[NOD-1064] Don't send GetBlockInvsMsg with lowHash = nil (#769)

* [NOD-900] Fix Seek not working at expected.

* [NOD-900] Wrap error messages.

* [NOD-900] Use ldbIterator.Key instead of LevelDBCursor.Key.

* [NOD-900] Add a comment.

blockdag/accept.go

@@ -6,7 +6,7 @@ package blockdag
 
 import (
 	"fmt"
-	"github.com/kaspanet/kaspad/database"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/pkg/errors"
 )
@@ -16,7 +16,17 @@ func (dag *BlockDAG) addNodeToIndexWithInvalidAncestor(block *util.Block) error
 	newNode, _ := dag.newBlockNode(blockHeader, newBlockSet())
 	newNode.status = statusInvalidAncestor
 	dag.index.AddNode(newNode)
-	return dag.index.flushToDB()
+
+	dbTx, err := dbaccess.NewTx()
+	if err != nil {
+		return err
+	}
+	defer dbTx.RollbackUnlessClosed()
+	err = dag.index.flushToDB(dbTx)
+	if err != nil {
+		return err
+	}
+	return dbTx.Commit()
 }
 
 // maybeAcceptBlock potentially accepts a block into the block DAG. It
@@ -62,13 +72,26 @@ func (dag *BlockDAG) maybeAcceptBlock(block *util.Block, flags BehaviorFlags) er
 	// expensive connection logic. It also has some other nice properties
 	// such as making blocks that never become part of the DAG or
 	// blocks that fail to connect available for further analysis.
-	err = dag.db.Update(func(dbTx database.Tx) error {
-		err := dbStoreBlock(dbTx, block)
+	dbTx, err := dbaccess.NewTx()
+	if err != nil {
+		return err
+	}
+	defer dbTx.RollbackUnlessClosed()
+	blockExists, err := dbaccess.HasBlock(dbTx, block.Hash())
+	if err != nil {
+		return err
+	}
+	if !blockExists {
+		err := storeBlock(dbTx, block)
 		if err != nil {
 			return err
 		}
-		return dag.index.flushToDBWithTx(dbTx)
-	})
+	}
+	err = dag.index.flushToDB(dbTx)
+	if err != nil {
+		return err
+	}
+	err = dbTx.Commit()
 	if err != nil {
 		return err
 	}

blockdag/accept_test.go

@@ -10,7 +10,7 @@ import (
 
 func TestMaybeAcceptBlockErrors(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("TestMaybeAcceptBlockErrors", Config{
+	dag, teardownFunc, err := DAGSetup("TestMaybeAcceptBlockErrors", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {

blockdag/blockheap_test.go

@@ -10,7 +10,7 @@ import (
 // TestBlockHeap tests pushing, popping, and determining the length of the heap.
 func TestBlockHeap(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("TestBlockHeap", Config{
+	dag, teardownFunc, err := DAGSetup("TestBlockHeap", true, Config{
 		DAGParams: &dagconfig.MainnetParams,
 	})
 	if err != nil {

blockdag/blockidhash.go

@@ -1,136 +0,0 @@
-package blockdag
-
-import (
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/util/daghash"
-	"github.com/pkg/errors"
-)
-
-var (
-	// idByHashIndexBucketName is the name of the db bucket used to house
-	// the block hash -> block id index.
-	idByHashIndexBucketName = []byte("idbyhashidx")
-
-	// hashByIDIndexBucketName is the name of the db bucket used to house
-	// the block id -> block hash index.
-	hashByIDIndexBucketName = []byte("hashbyididx")
-
-	currentBlockIDKey = []byte("currentblockid")
-)
-
-// -----------------------------------------------------------------------------
-// This is a mapping between block hashes and unique IDs. The ID
-// is simply a sequentially incremented uint64 that is used instead of block hash
-// for the indexers. This is useful because it is only 8 bytes versus 32 bytes
-// hashes and thus saves a ton of space when a block is referenced in an index.
-// It consists of three buckets: the first bucket maps the hash of each
-// block to the unique ID and the second maps that ID back to the block hash.
-// The third bucket contains the last received block ID, and is used
-// when starting the node to check that the enabled indexes are up to date
-// with the latest received block, and if not, initiate recovery process.
-//
-// The serialized format for keys and values in the block hash to ID bucket is:
-//   <hash> = <ID>
-//
-//   Field           Type              Size
-//   hash            daghash.Hash     32 bytes
-//   ID              uint64            8 bytes
-//   -----
-//   Total: 40 bytes
-//
-// The serialized format for keys and values in the ID to block hash bucket is:
-//   <ID> = <hash>
-//
-//   Field           Type              Size
-//   ID              uint64            8 bytes
-//   hash            daghash.Hash     32 bytes
-//   -----
-//   Total: 40 bytes
-//
-// -----------------------------------------------------------------------------
-
-const blockIDSize = 8 // 8 bytes for block ID
-
-// DBFetchBlockIDByHash uses an existing database transaction to retrieve the
-// block id for the provided hash from the index.
-func DBFetchBlockIDByHash(dbTx database.Tx, hash *daghash.Hash) (uint64, error) {
-	hashIndex := dbTx.Metadata().Bucket(idByHashIndexBucketName)
-	serializedID := hashIndex.Get(hash[:])
-	if serializedID == nil {
-		return 0, errors.Errorf("no entry in the block ID index for block with hash %s", hash)
-	}
-
-	return DeserializeBlockID(serializedID), nil
-}
-
-// DBFetchBlockHashBySerializedID uses an existing database transaction to
-// retrieve the hash for the provided serialized block id from the index.
-func DBFetchBlockHashBySerializedID(dbTx database.Tx, serializedID []byte) (*daghash.Hash, error) {
-	idIndex := dbTx.Metadata().Bucket(hashByIDIndexBucketName)
-	hashBytes := idIndex.Get(serializedID)
-	if hashBytes == nil {
-		return nil, errors.Errorf("no entry in the block ID index for block with id %d", byteOrder.Uint64(serializedID))
-	}
-
-	var hash daghash.Hash
-	copy(hash[:], hashBytes)
-	return &hash, nil
-}
-
-// dbPutBlockIDIndexEntry uses an existing database transaction to update or add
-// the index entries for the hash to id and id to hash mappings for the provided
-// values.
-func dbPutBlockIDIndexEntry(dbTx database.Tx, hash *daghash.Hash, serializedID []byte) error {
-	// Add the block hash to ID mapping to the index.
-	meta := dbTx.Metadata()
-	hashIndex := meta.Bucket(idByHashIndexBucketName)
-	if err := hashIndex.Put(hash[:], serializedID[:]); err != nil {
-		return err
-	}
-
-	// Add the block ID to hash mapping to the index.
-	idIndex := meta.Bucket(hashByIDIndexBucketName)
-	return idIndex.Put(serializedID[:], hash[:])
-}
-
-// DBFetchCurrentBlockID returns the last known block ID.
-func DBFetchCurrentBlockID(dbTx database.Tx) uint64 {
-	serializedID := dbTx.Metadata().Get(currentBlockIDKey)
-	if serializedID == nil {
-		return 0
-	}
-	return DeserializeBlockID(serializedID)
-}
-
-// DeserializeBlockID returns a deserialized block id
-func DeserializeBlockID(serializedID []byte) uint64 {
-	return byteOrder.Uint64(serializedID)
-}
-
-// SerializeBlockID returns a serialized block id
-func SerializeBlockID(blockID uint64) []byte {
-	serializedBlockID := make([]byte, blockIDSize)
-	byteOrder.PutUint64(serializedBlockID, blockID)
-	return serializedBlockID
-}
-
-// DBFetchBlockHashByID uses an existing database transaction to retrieve the
-// hash for the provided block id from the index.
-func DBFetchBlockHashByID(dbTx database.Tx, id uint64) (*daghash.Hash, error) {
-	return DBFetchBlockHashBySerializedID(dbTx, SerializeBlockID(id))
-}
-
-func createBlockID(dbTx database.Tx, blockHash *daghash.Hash) (uint64, error) {
-	currentBlockID := DBFetchCurrentBlockID(dbTx)
-	newBlockID := currentBlockID + 1
-	serializedNewBlockID := SerializeBlockID(newBlockID)
-	err := dbTx.Metadata().Put(currentBlockIDKey, serializedNewBlockID)
-	if err != nil {
-		return 0, err
-	}
-	err = dbPutBlockIDIndexEntry(dbTx, blockHash, serializedNewBlockID)
-	if err != nil {
-		return 0, err
-	}
-	return newBlockID, nil
-}

blockdag/blockindex.go

@@ -5,10 +5,10 @@
 package blockdag
 
 import (
+	"github.com/kaspanet/kaspad/dbaccess"
 	"sync"
 
 	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
 	"github.com/kaspanet/kaspad/util/daghash"
 )
 
@@ -18,7 +18,6 @@ type blockIndex struct {
 	// The following fields are set when the instance is created and can't
 	// be changed afterwards, so there is no need to protect them with a
 	// separate mutex.
-	db        database.DB
 	dagParams *dagconfig.Params
 
 	sync.RWMutex
@@ -29,9 +28,8 @@ type blockIndex struct {
 // newBlockIndex returns a new empty instance of a block index. The index will
 // be dynamically populated as block nodes are loaded from the database and
 // manually added.
-func newBlockIndex(db database.DB, dagParams *dagconfig.Params) *blockIndex {
+func newBlockIndex(dagParams *dagconfig.Params) *blockIndex {
 	return &blockIndex{
-		db:        db,
 		dagParams: dagParams,
 		index:     make(map[daghash.Hash]*blockNode),
 		dirty:     make(map[*blockNode]struct{}),
@@ -111,17 +109,8 @@ func (bi *blockIndex) UnsetStatusFlags(node *blockNode, flags blockStatus) {
 	bi.dirty[node] = struct{}{}
 }
 
-// flushToDB writes all dirty block nodes to the database. If all writes
-// succeed, this clears the dirty set.
-func (bi *blockIndex) flushToDB() error {
-	return bi.db.Update(func(dbTx database.Tx) error {
-		return bi.flushToDBWithTx(dbTx)
-	})
-}
-
-// flushToDBWithTx writes all dirty block nodes to the database. If all
-// writes succeed, this clears the dirty set.
-func (bi *blockIndex) flushToDBWithTx(dbTx database.Tx) error {
+// flushToDB writes all dirty block nodes to the database.
+func (bi *blockIndex) flushToDB(dbContext *dbaccess.TxContext) error {
 	bi.Lock()
 	defer bi.Unlock()
 	if len(bi.dirty) == 0 {
@@ -129,7 +118,12 @@ func (bi *blockIndex) flushToDBWithTx(dbTx database.Tx) error {
 	}
 
 	for node := range bi.dirty {
-		err := dbStoreBlockNode(dbTx, node)
+		serializedBlockNode, err := serializeBlockNode(node)
+		if err != nil {
+			return err
+		}
+		key := blockIndexKey(node.hash, node.blueScore)
+		err = dbaccess.StoreIndexBlock(dbContext, key, serializedBlockNode)
 		if err != nil {
 			return err
 		}

blockdag/blockindex_test.go

@@ -10,7 +10,7 @@ import (
 func TestAncestorErrors(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
 	params := dagconfig.SimnetParams
-	dag, teardownFunc, err := DAGSetup("TestAncestorErrors", Config{
+	dag, teardownFunc, err := DAGSetup("TestAncestorErrors", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {

blockdag/blocknode.go

@@ -110,7 +110,7 @@ func (dag *BlockDAG) newBlockNode(blockHeader *wire.BlockHeader, parents blockSe
 		parents:            parents,
 		children:           make(blockSet),
 		blueScore:          math.MaxUint64, // Initialized to the max value to avoid collisions with the genesis block
-		timestamp:          dag.AdjustedTime().Unix(),
+		timestamp:          dag.Now().Unix(),
 		bluesAnticoneSizes: make(map[*blockNode]dagconfig.KType),
 	}
 

blockdag/blocknode_test.go

@@ -9,7 +9,7 @@ import (
 // This test is to ensure the size BlueAnticoneSizesSize is serialized to the size of KType.
 // We verify that by serializing and deserializing the block while making sure that we stay within the expected range.
 func TestBlueAnticoneSizesSize(t *testing.T) {
-	dag, teardownFunc, err := DAGSetup("TestBlueAnticoneSizesSize", Config{
+	dag, teardownFunc, err := DAGSetup("TestBlueAnticoneSizesSize", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {

blockdag/blockwindow_test.go

@@ -12,7 +12,7 @@ import (
 func TestBlueBlockWindow(t *testing.T) {
 	params := dagconfig.SimnetParams
 	params.K = 1
-	dag, teardownFunc, err := DAGSetup("TestBlueBlockWindow", Config{
+	dag, teardownFunc, err := DAGSetup("TestBlueBlockWindow", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {

blockdag/coinbase.go

@@ -4,12 +4,12 @@ import (
 	"bufio"
 	"bytes"
 	"encoding/binary"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util/subnetworkid"
 	"github.com/pkg/errors"
 	"io"
 	"math"
 
-	"github.com/kaspanet/kaspad/database"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/util/txsort"
@@ -73,55 +73,24 @@ func (cfr *compactFeeIterator) next() (uint64, error) {
 }
 
 // The following functions relate to storing and retrieving fee data from the database
-var feeBucket = []byte("fees")
 
 // getBluesFeeData returns the compactFeeData for all nodes's blues,
 // used to calculate the fees this blockNode needs to pay
 func (node *blockNode) getBluesFeeData(dag *BlockDAG) (map[daghash.Hash]compactFeeData, error) {
 	bluesFeeData := make(map[daghash.Hash]compactFeeData)
 
-	err := dag.db.View(func(dbTx database.Tx) error {
-		for _, blueBlock := range node.blues {
-			feeData, err := dbFetchFeeData(dbTx, blueBlock.hash)
-			if err != nil {
-				return errors.Errorf("Error getting fee data for block %s: %s", blueBlock.hash, err)
-			}
-
-			bluesFeeData[*blueBlock.hash] = feeData
+	for _, blueBlock := range node.blues {
+		feeData, err := dbaccess.FetchFeeData(dbaccess.NoTx(), blueBlock.hash)
+		if err != nil {
+			return nil, err
 		}
 
-		return nil
-	})
-	if err != nil {
-		return nil, err
+		bluesFeeData[*blueBlock.hash] = feeData
 	}
 
 	return bluesFeeData, nil
 }
 
-func dbStoreFeeData(dbTx database.Tx, blockHash *daghash.Hash, feeData compactFeeData) error {
-	feeBucket, err := dbTx.Metadata().CreateBucketIfNotExists(feeBucket)
-	if err != nil {
-		return errors.Errorf("Error creating or retrieving fee bucket: %s", err)
-	}
-
-	return feeBucket.Put(blockHash.CloneBytes(), feeData)
-}
-
-func dbFetchFeeData(dbTx database.Tx, blockHash *daghash.Hash) (compactFeeData, error) {
-	feeBucket := dbTx.Metadata().Bucket(feeBucket)
-	if feeBucket == nil {
-		return nil, errors.New("Fee bucket does not exist")
-	}
-
-	feeData := feeBucket.Get(blockHash.CloneBytes())
-	if feeData == nil {
-		return nil, errors.Errorf("No fee data found for block %s", blockHash)
-	}
-
-	return feeData, nil
-}
-
 // The following functions deal with building and validating the coinbase transaction
 
 func (node *blockNode) validateCoinbaseTransaction(dag *BlockDAG, block *util.Block, txsAcceptanceData MultiBlockTxsAcceptanceData) error {

blockdag/common_test.go

@@ -17,7 +17,6 @@ import (
 	"time"
 
 	"github.com/kaspanet/kaspad/dagconfig"
-	_ "github.com/kaspanet/kaspad/database/ffldb"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
@@ -73,15 +72,8 @@ func loadUTXOSet(filename string) (UTXOSet, error) {
 			return nil, err
 		}
 
-		// Serialized utxo entry.
-		serialized := make([]byte, numBytes)
-		_, err = io.ReadAtLeast(r, serialized, int(numBytes))
-		if err != nil {
-			return nil, err
-		}
-
-		// Deserialize it and add it to the view.
-		entry, err := deserializeUTXOEntry(serialized)
+		// Deserialize the UTXO entry and add it to the UTXO set.
+		entry, err := deserializeUTXOEntry(r)
 		if err != nil {
 			return nil, err
 		}
@@ -102,11 +94,11 @@ func (dag *BlockDAG) TestSetCoinbaseMaturity(maturity uint64) {
 // it is not usable with all functions and the tests must take care when making
 // use of it.
 func newTestDAG(params *dagconfig.Params) *BlockDAG {
-	index := newBlockIndex(nil, params)
+	index := newBlockIndex(params)
 	targetTimePerBlock := int64(params.TargetTimePerBlock / time.Second)
 	dag := &BlockDAG{
 		dagParams:                      params,
-		timeSource:                     NewMedianTime(),
+		timeSource:                     NewTimeSource(),
 		targetTimePerBlock:             targetTimePerBlock,
 		difficultyAdjustmentWindowSize: params.DifficultyAdjustmentWindowSize,
 		TimestampDeviationTolerance:    params.TimestampDeviationTolerance,
@@ -211,3 +203,15 @@ func nodeByMsgBlock(t *testing.T, dag *BlockDAG, block *wire.MsgBlock) *blockNod
 	}
 	return node
 }
+
+type fakeTimeSource struct {
+	time time.Time
+}
+
+func (fts *fakeTimeSource) Now() time.Time {
+	return time.Unix(fts.time.Unix(), 0)
+}
+
+func newFakeTimeSource(fakeTime time.Time) TimeSource {
+	return &fakeTimeSource{time: fakeTime}
+}

blockdag/compress.go

@@ -1,584 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package blockdag
-
-import (
-	"github.com/kaspanet/kaspad/ecc"
-	"github.com/kaspanet/kaspad/txscript"
-)
-
-// -----------------------------------------------------------------------------
-// A variable length quantity (VLQ) is an encoding that uses an arbitrary number
-// of binary octets to represent an arbitrarily large integer. The scheme
-// employs a most significant byte (MSB) base-128 encoding where the high bit in
-// each byte indicates whether or not the byte is the final one. In addition,
-// to ensure there are no redundant encodings, an offset is subtracted every
-// time a group of 7 bits is shifted out. Therefore each integer can be
-// represented in exactly one way, and each representation stands for exactly
-// one integer.
-//
-// Another nice property of this encoding is that it provides a compact
-// representation of values that are typically used to indicate sizes. For
-// example, the values 0 - 127 are represented with a single byte, 128 - 16511
-// with two bytes, and 16512 - 2113663 with three bytes.
-//
-// While the encoding allows arbitrarily large integers, it is artificially
-// limited in this code to an unsigned 64-bit integer for efficiency purposes.
-//
-// Example encodings:
-//           0 -> [0x00]
-//         127 -> [0x7f]                 * Max 1-byte value
-//         128 -> [0x80 0x00]
-//         129 -> [0x80 0x01]
-//         255 -> [0x80 0x7f]
-//         256 -> [0x81 0x00]
-//       16511 -> [0xff 0x7f]            * Max 2-byte value
-//       16512 -> [0x80 0x80 0x00]
-//       32895 -> [0x80 0xff 0x7f]
-//     2113663 -> [0xff 0xff 0x7f]       * Max 3-byte value
-//   270549119 -> [0xff 0xff 0xff 0x7f]  * Max 4-byte value
-//      2^64-1 -> [0x80 0xfe 0xfe 0xfe 0xfe 0xfe 0xfe 0xfe 0xfe 0x7f]
-//
-// References:
-//   https://en.wikipedia.org/wiki/Variable-length_quantity
-//   http://www.codecodex.com/wiki/Variable-Length_Integers
-// -----------------------------------------------------------------------------
-
-// serializeSizeVLQ returns the number of bytes it would take to serialize the
-// passed number as a variable-length quantity according to the format described
-// above.
-func serializeSizeVLQ(n uint64) int {
-	size := 1
-	for ; n > 0x7f; n = (n >> 7) - 1 {
-		size++
-	}
-
-	return size
-}
-
-// putVLQ serializes the provided number to a variable-length quantity according
-// to the format described above and returns the number of bytes of the encoded
-// value. The result is placed directly into the passed byte slice which must
-// be at least large enough to handle the number of bytes returned by the
-// serializeSizeVLQ function or it will panic.
-func putVLQ(target []byte, n uint64) int {
-	offset := 0
-	for ; ; offset++ {
-		// The high bit is set when another byte follows.
-		highBitMask := byte(0x80)
-		if offset == 0 {
-			highBitMask = 0x00
-		}
-
-		target[offset] = byte(n&0x7f) | highBitMask
-		if n <= 0x7f {
-			break
-		}
-		n = (n >> 7) - 1
-	}
-
-	// Reverse the bytes so it is MSB-encoded.
-	for i, j := 0, offset; i < j; i, j = i+1, j-1 {
-		target[i], target[j] = target[j], target[i]
-	}
-
-	return offset + 1
-}
-
-// deserializeVLQ deserializes the provided variable-length quantity according
-// to the format described above. It also returns the number of bytes
-// deserialized.
-func deserializeVLQ(serialized []byte) (uint64, int) {
-	var n uint64
-	var size int
-	for _, val := range serialized {
-		size++
-		n = (n << 7) | uint64(val&0x7f)
-		if val&0x80 != 0x80 {
-			break
-		}
-		n++
-	}
-
-	return n, size
-}
-
-// -----------------------------------------------------------------------------
-// In order to reduce the size of stored scripts, a domain specific compression
-// algorithm is used which recognizes standard scripts and stores them using
-// less bytes than the original script.
-//
-// The general serialized format is:
-//
-//   <script size or type><script data>
-//
-//   Field                 Type     Size
-//   script size or type   VLQ      variable
-//   script data           []byte   variable
-//
-// The specific serialized format for each recognized standard script is:
-//
-// - Pay-to-pubkey-hash: (21 bytes) - <0><20-byte pubkey hash>
-// - Pay-to-script-hash: (21 bytes) - <1><20-byte script hash>
-// - Pay-to-pubkey**:    (33 bytes) - <2, 3, 4, or 5><32-byte pubkey X value>
-//   2, 3 = compressed pubkey with bit 0 specifying the y coordinate to use
-//   4, 5 = uncompressed pubkey with bit 0 specifying the y coordinate to use
-//   ** Only valid public keys starting with 0x02, 0x03, and 0x04 are supported.
-//
-// Any scripts which are not recognized as one of the aforementioned standard
-// scripts are encoded using the general serialized format and encode the script
-// size as the sum of the actual size of the script and the number of special
-// cases.
-// -----------------------------------------------------------------------------
-
-// The following constants specify the special constants used to identify a
-// special script type in the domain-specific compressed script encoding.
-//
-// NOTE: This section specifically does not use iota since these values are
-// serialized and must be stable for long-term storage.
-const (
-	// cstPayToPubKeyHash identifies a compressed pay-to-pubkey-hash script.
-	cstPayToPubKeyHash = 0
-
-	// cstPayToScriptHash identifies a compressed pay-to-script-hash script.
-	cstPayToScriptHash = 1
-
-	// cstPayToPubKeyComp2 identifies a compressed pay-to-pubkey script to
-	// a compressed pubkey. Bit 0 specifies which y-coordinate to use
-	// to reconstruct the full uncompressed pubkey.
-	cstPayToPubKeyComp2 = 2
-
-	// cstPayToPubKeyComp3 identifies a compressed pay-to-pubkey script to
-	// a compressed pubkey. Bit 0 specifies which y-coordinate to use
-	// to reconstruct the full uncompressed pubkey.
-	cstPayToPubKeyComp3 = 3
-
-	// cstPayToPubKeyUncomp4 identifies a compressed pay-to-pubkey script to
-	// an uncompressed pubkey. Bit 0 specifies which y-coordinate to use
-	// to reconstruct the full uncompressed pubkey.
-	cstPayToPubKeyUncomp4 = 4
-
-	// cstPayToPubKeyUncomp5 identifies a compressed pay-to-pubkey script to
-	// an uncompressed pubkey. Bit 0 specifies which y-coordinate to use
-	// to reconstruct the full uncompressed pubkey.
-	cstPayToPubKeyUncomp5 = 5
-
-	// numSpecialScripts is the number of special scripts recognized by the
-	// domain-specific script compression algorithm.
-	numSpecialScripts = 6
-)
-
-// isPubKeyHash returns whether or not the passed public key script is a
-// standard pay-to-pubkey-hash script along with the pubkey hash it is paying to
-// if it is.
-func isPubKeyHash(script []byte) (bool, []byte) {
-	if len(script) == 25 && script[0] == txscript.OpDup &&
-		script[1] == txscript.OpHash160 &&
-		script[2] == txscript.OpData20 &&
-		script[23] == txscript.OpEqualVerify &&
-		script[24] == txscript.OpCheckSig {
-
-		return true, script[3:23]
-	}
-
-	return false, nil
-}
-
-// isScriptHash returns whether or not the passed public key script is a
-// standard pay-to-script-hash script along with the script hash it is paying to
-// if it is.
-func isScriptHash(script []byte) (bool, []byte) {
-	if len(script) == 23 && script[0] == txscript.OpHash160 &&
-		script[1] == txscript.OpData20 &&
-		script[22] == txscript.OpEqual {
-
-		return true, script[2:22]
-	}
-
-	return false, nil
-}
-
-// isPubKey returns whether or not the passed public key script is a standard
-// pay-to-pubkey script that pays to a valid compressed or uncompressed public
-// key along with the serialized pubkey it is paying to if it is.
-//
-// NOTE: This function ensures the public key is actually valid since the
-// compression algorithm requires valid pubkeys. It does not support hybrid
-// pubkeys. This means that even if the script has the correct form for a
-// pay-to-pubkey script, this function will only return true when it is paying
-// to a valid compressed or uncompressed pubkey.
-func isPubKey(script []byte) (bool, []byte) {
-	// Pay-to-compressed-pubkey script.
-	if len(script) == 35 && script[0] == txscript.OpData33 &&
-		script[34] == txscript.OpCheckSig && (script[1] == 0x02 ||
-		script[1] == 0x03) {
-
-		// Ensure the public key is valid.
-		serializedPubKey := script[1:34]
-		_, err := ecc.ParsePubKey(serializedPubKey, ecc.S256())
-		if err == nil {
-			return true, serializedPubKey
-		}
-	}
-
-	// Pay-to-uncompressed-pubkey script.
-	if len(script) == 67 && script[0] == txscript.OpData65 &&
-		script[66] == txscript.OpCheckSig && script[1] == 0x04 {
-
-		// Ensure the public key is valid.
-		serializedPubKey := script[1:66]
-		_, err := ecc.ParsePubKey(serializedPubKey, ecc.S256())
-		if err == nil {
-			return true, serializedPubKey
-		}
-	}
-
-	return false, nil
-}
-
-// compressedScriptSize returns the number of bytes the passed script would take
-// when encoded with the domain specific compression algorithm described above.
-func compressedScriptSize(scriptPubKey []byte) int {
-	// Pay-to-pubkey-hash script.
-	if valid, _ := isPubKeyHash(scriptPubKey); valid {
-		return 21
-	}
-
-	// Pay-to-script-hash script.
-	if valid, _ := isScriptHash(scriptPubKey); valid {
-		return 21
-	}
-
-	// Pay-to-pubkey (compressed or uncompressed) script.
-	if valid, _ := isPubKey(scriptPubKey); valid {
-		return 33
-	}
-
-	// When none of the above special cases apply, encode the script as is
-	// preceded by the sum of its size and the number of special cases
-	// encoded as a variable length quantity.
-	return serializeSizeVLQ(uint64(len(scriptPubKey)+numSpecialScripts)) +
-		len(scriptPubKey)
-}
-
-// decodeCompressedScriptSize treats the passed serialized bytes as a compressed
-// script, possibly followed by other data, and returns the number of bytes it
-// occupies taking into account the special encoding of the script size by the
-// domain specific compression algorithm described above.
-func decodeCompressedScriptSize(serialized []byte) int {
-	scriptSize, bytesRead := deserializeVLQ(serialized)
-	if bytesRead == 0 {
-		return 0
-	}
-
-	switch scriptSize {
-	case cstPayToPubKeyHash:
-		return 21
-
-	case cstPayToScriptHash:
-		return 21
-
-	case cstPayToPubKeyComp2, cstPayToPubKeyComp3, cstPayToPubKeyUncomp4,
-		cstPayToPubKeyUncomp5:
-		return 33
-	}
-
-	scriptSize -= numSpecialScripts
-	scriptSize += uint64(bytesRead)
-	return int(scriptSize)
-}
-
-// putCompressedScript compresses the passed script according to the domain
-// specific compression algorithm described above directly into the passed
-// target byte slice. The target byte slice must be at least large enough to
-// handle the number of bytes returned by the compressedScriptSize function or
-// it will panic.
-func putCompressedScript(target, scriptPubKey []byte) int {
-	// Pay-to-pubkey-hash script.
-	if valid, hash := isPubKeyHash(scriptPubKey); valid {
-		target[0] = cstPayToPubKeyHash
-		copy(target[1:21], hash)
-		return 21
-	}
-
-	// Pay-to-script-hash script.
-	if valid, hash := isScriptHash(scriptPubKey); valid {
-		target[0] = cstPayToScriptHash
-		copy(target[1:21], hash)
-		return 21
-	}
-
-	// Pay-to-pubkey (compressed or uncompressed) script.
-	if valid, serializedPubKey := isPubKey(scriptPubKey); valid {
-		pubKeyFormat := serializedPubKey[0]
-		switch pubKeyFormat {
-		case 0x02, 0x03:
-			target[0] = pubKeyFormat
-			copy(target[1:33], serializedPubKey[1:33])
-			return 33
-		case 0x04:
-			// Encode the oddness of the serialized pubkey into the
-			// compressed script type.
-			target[0] = pubKeyFormat | (serializedPubKey[64] & 0x01)
-			copy(target[1:33], serializedPubKey[1:33])
-			return 33
-		}
-	}
-
-	// When none of the above special cases apply, encode the unmodified
-	// script preceded by the sum of its size and the number of special
-	// cases encoded as a variable length quantity.
-	encodedSize := uint64(len(scriptPubKey) + numSpecialScripts)
-	vlqSizeLen := putVLQ(target, encodedSize)
-	copy(target[vlqSizeLen:], scriptPubKey)
-	return vlqSizeLen + len(scriptPubKey)
-}
-
-// decompressScript returns the original script obtained by decompressing the
-// passed compressed script according to the domain specific compression
-// algorithm described above.
-//
-// NOTE: The script parameter must already have been proven to be long enough
-// to contain the number of bytes returned by decodeCompressedScriptSize or it
-// will panic. This is acceptable since it is only an internal function.
-func decompressScript(compressedScriptPubKey []byte) []byte {
-	// In practice this function will not be called with a zero-length or
-	// nil script since the nil script encoding includes the length, however
-	// the code below assumes the length exists, so just return nil now if
-	// the function ever ends up being called with a nil script in the
-	// future.
-	if len(compressedScriptPubKey) == 0 {
-		return nil
-	}
-
-	// Decode the script size and examine it for the special cases.
-	encodedScriptSize, bytesRead := deserializeVLQ(compressedScriptPubKey)
-	switch encodedScriptSize {
-	// Pay-to-pubkey-hash script. The resulting script is:
-	// <OP_DUP><OP_HASH160><20 byte hash><OP_EQUALVERIFY><OP_CHECKSIG>
-	case cstPayToPubKeyHash:
-		scriptPubKey := make([]byte, 25)
-		scriptPubKey[0] = txscript.OpDup
-		scriptPubKey[1] = txscript.OpHash160
-		scriptPubKey[2] = txscript.OpData20
-		copy(scriptPubKey[3:], compressedScriptPubKey[bytesRead:bytesRead+20])
-		scriptPubKey[23] = txscript.OpEqualVerify
-		scriptPubKey[24] = txscript.OpCheckSig
-		return scriptPubKey
-
-	// Pay-to-script-hash script. The resulting script is:
-	// <OP_HASH160><20 byte script hash><OP_EQUAL>
-	case cstPayToScriptHash:
-		scriptPubKey := make([]byte, 23)
-		scriptPubKey[0] = txscript.OpHash160
-		scriptPubKey[1] = txscript.OpData20
-		copy(scriptPubKey[2:], compressedScriptPubKey[bytesRead:bytesRead+20])
-		scriptPubKey[22] = txscript.OpEqual
-		return scriptPubKey
-
-	// Pay-to-compressed-pubkey script. The resulting script is:
-	// <OP_DATA_33><33 byte compressed pubkey><OP_CHECKSIG>
-	case cstPayToPubKeyComp2, cstPayToPubKeyComp3:
-		scriptPubKey := make([]byte, 35)
-		scriptPubKey[0] = txscript.OpData33
-		scriptPubKey[1] = byte(encodedScriptSize)
-		copy(scriptPubKey[2:], compressedScriptPubKey[bytesRead:bytesRead+32])
-		scriptPubKey[34] = txscript.OpCheckSig
-		return scriptPubKey
-
-	// Pay-to-uncompressed-pubkey script. The resulting script is:
-	// <OP_DATA_65><65 byte uncompressed pubkey><OP_CHECKSIG>
-	case cstPayToPubKeyUncomp4, cstPayToPubKeyUncomp5:
-		// Change the leading byte to the appropriate compressed pubkey
-		// identifier (0x02 or 0x03) so it can be decoded as a
-		// compressed pubkey. This really should never fail since the
-		// encoding ensures it is valid before compressing to this type.
-		compressedKey := make([]byte, 33)
-		compressedKey[0] = byte(encodedScriptSize - 2)
-		copy(compressedKey[1:], compressedScriptPubKey[1:])
-		key, err := ecc.ParsePubKey(compressedKey, ecc.S256())
-		if err != nil {
-			return nil
-		}
-
-		scriptPubKey := make([]byte, 67)
-		scriptPubKey[0] = txscript.OpData65
-		copy(scriptPubKey[1:], key.SerializeUncompressed())
-		scriptPubKey[66] = txscript.OpCheckSig
-		return scriptPubKey
-	}
-
-	// When none of the special cases apply, the script was encoded using
-	// the general format, so reduce the script size by the number of
-	// special cases and return the unmodified script.
-	scriptSize := int(encodedScriptSize - numSpecialScripts)
-	scriptPubKey := make([]byte, scriptSize)
-	copy(scriptPubKey, compressedScriptPubKey[bytesRead:bytesRead+scriptSize])
-	return scriptPubKey
-}
-
-// -----------------------------------------------------------------------------
-// In order to reduce the size of stored amounts, a domain specific compression
-// algorithm is used which relies on there typically being a lot of zeroes at
-// end of the amounts.
-//
-// While this is simply exchanging one uint64 for another, the resulting value
-// for typical amounts has a much smaller magnitude which results in fewer bytes
-// when encoded as variable length quantity. For example, consider the amount
-// of 0.1 KAS which is 10000000 sompi. Encoding 10000000 as a VLQ would take
-// 4 bytes while encoding the compressed value of 8 as a VLQ only takes 1 byte.
-//
-// Essentially the compression is achieved by splitting the value into an
-// exponent in the range [0-9] and a digit in the range [1-9], when possible,
-// and encoding them in a way that can be decoded. More specifically, the
-// encoding is as follows:
-// - 0 is 0
-// - Find the exponent, e, as the largest power of 10 that evenly divides the
-//   value up to a maximum of 9
-// - When e < 9, the final digit can't be 0 so store it as d and remove it by
-//   dividing the value by 10 (call the result n). The encoded value is thus:
-//   1 + 10*(9*n + d-1) + e
-// - When e==9, the only thing known is the amount is not 0. The encoded value
-//   is thus:
-//   1 + 10*(n-1) + e   ==   10 + 10*(n-1)
-//
-// Example encodings:
-// (The numbers in parenthesis are the number of bytes when serialized as a VLQ)
-//            0 (1) -> 0        (1)           *  0.00000000 KAS
-//         1000 (2) -> 4        (1)           *  0.00001000 KAS
-//        10000 (2) -> 5        (1)           *  0.00010000 KAS
-//     12345678 (4) -> 111111101(4)           *  0.12345678 KAS
-//     50000000 (4) -> 47       (1)           *  0.50000000 KAS
-//    100000000 (4) -> 9        (1)           *  1.00000000 KAS
-//    500000000 (5) -> 49       (1)           *  5.00000000 KAS
-//   1000000000 (5) -> 10       (1)           * 10.00000000 KAS
-// -----------------------------------------------------------------------------
-
-// compressTxOutAmount compresses the passed amount according to the domain
-// specific compression algorithm described above.
-func compressTxOutAmount(amount uint64) uint64 {
-	// No need to do any work if it's zero.
-	if amount == 0 {
-		return 0
-	}
-
-	// Find the largest power of 10 (max of 9) that evenly divides the
-	// value.
-	exponent := uint64(0)
-	for amount%10 == 0 && exponent < 9 {
-		amount /= 10
-		exponent++
-	}
-
-	// The compressed result for exponents less than 9 is:
-	// 1 + 10*(9*n + d-1) + e
-	if exponent < 9 {
-		lastDigit := amount % 10
-		amount /= 10
-		return 1 + 10*(9*amount+lastDigit-1) + exponent
-	}
-
-	// The compressed result for an exponent of 9 is:
-	// 1 + 10*(n-1) + e   ==   10 + 10*(n-1)
-	return 10 + 10*(amount-1)
-}
-
-// decompressTxOutAmount returns the original amount the passed compressed
-// amount represents according to the domain specific compression algorithm
-// described above.
-func decompressTxOutAmount(amount uint64) uint64 {
-	// No need to do any work if it's zero.
-	if amount == 0 {
-		return 0
-	}
-
-	// The decompressed amount is either of the following two equations:
-	// x = 1 + 10*(9*n + d - 1) + e
-	// x = 1 + 10*(n - 1)       + 9
-	amount--
-
-	// The decompressed amount is now one of the following two equations:
-	// x = 10*(9*n + d - 1) + e
-	// x = 10*(n - 1)       + 9
-	exponent := amount % 10
-	amount /= 10
-
-	// The decompressed amount is now one of the following two equations:
-	// x = 9*n + d - 1  | where e < 9
-	// x = n - 1        | where e = 9
-	n := uint64(0)
-	if exponent < 9 {
-		lastDigit := amount%9 + 1
-		amount /= 9
-		n = amount*10 + lastDigit
-	} else {
-		n = amount + 1
-	}
-
-	// Apply the exponent.
-	for ; exponent > 0; exponent-- {
-		n *= 10
-	}
-
-	return n
-}
-
-// -----------------------------------------------------------------------------
-// Compressed transaction outputs consist of an amount and a public key script
-// both compressed using the domain specific compression algorithms previously
-// described.
-//
-// The serialized format is:
-//
-//   <compressed amount><compressed script>
-//
-//   Field                 Type     Size
-//     compressed amount   VLQ      variable
-//     compressed script   []byte   variable
-// -----------------------------------------------------------------------------
-
-// compressedTxOutSize returns the number of bytes the passed transaction output
-// fields would take when encoded with the format described above.
-func compressedTxOutSize(amount uint64, scriptPubKey []byte) int {
-	return serializeSizeVLQ(compressTxOutAmount(amount)) +
-		compressedScriptSize(scriptPubKey)
-}
-
-// putCompressedTxOut compresses the passed amount and script according to their
-// domain specific compression algorithms and encodes them directly into the
-// passed target byte slice with the format described above. The target byte
-// slice must be at least large enough to handle the number of bytes returned by
-// the compressedTxOutSize function or it will panic.
-func putCompressedTxOut(target []byte, amount uint64, scriptPubKey []byte) int {
-	offset := putVLQ(target, compressTxOutAmount(amount))
-	offset += putCompressedScript(target[offset:], scriptPubKey)
-	return offset
-}
-
-// decodeCompressedTxOut decodes the passed compressed txout, possibly followed
-// by other data, into its uncompressed amount and script and returns them along
-// with the number of bytes they occupied prior to decompression.
-func decodeCompressedTxOut(serialized []byte) (uint64, []byte, int, error) {
-	// Deserialize the compressed amount and ensure there are bytes
-	// remaining for the compressed script.
-	compressedAmount, bytesRead := deserializeVLQ(serialized)
-	if bytesRead >= len(serialized) {
-		return 0, nil, bytesRead, errDeserialize("unexpected end of " +
-			"data after compressed amount")
-	}
-
-	// Decode the compressed script size and ensure there are enough bytes
-	// left in the slice for it.
-	scriptSize := decodeCompressedScriptSize(serialized[bytesRead:])
-	if len(serialized[bytesRead:]) < scriptSize {
-		return 0, nil, bytesRead, errDeserialize("unexpected end of " +
-			"data after script size")
-	}
-
-	// Decompress and return the amount and script.
-	amount := decompressTxOutAmount(compressedAmount)
-	script := decompressScript(serialized[bytesRead : bytesRead+scriptSize])
-	return amount, script, bytesRead + scriptSize, nil
-}

blockdag/compress_test.go

@@ -1,436 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package blockdag
-
-import (
-	"bytes"
-	"encoding/hex"
-	"testing"
-)
-
-// hexToBytes converts the passed hex string into bytes and will panic if there
-// is an error. This is only provided for the hard-coded constants so errors in
-// the source code can be detected. It will only (and must only) be called with
-// hard-coded values.
-func hexToBytes(s string) []byte {
-	b, err := hex.DecodeString(s)
-	if err != nil {
-		panic("invalid hex in source file: " + s)
-	}
-	return b
-}
-
-// TestVLQ ensures the variable length quantity serialization, deserialization,
-// and size calculation works as expected.
-func TestVLQ(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		val        uint64
-		serialized []byte
-	}{
-		{0, hexToBytes("00")},
-		{1, hexToBytes("01")},
-		{127, hexToBytes("7f")},
-		{128, hexToBytes("8000")},
-		{129, hexToBytes("8001")},
-		{255, hexToBytes("807f")},
-		{256, hexToBytes("8100")},
-		{16383, hexToBytes("fe7f")},
-		{16384, hexToBytes("ff00")},
-		{16511, hexToBytes("ff7f")}, // Max 2-byte value
-		{16512, hexToBytes("808000")},
-		{16513, hexToBytes("808001")},
-		{16639, hexToBytes("80807f")},
-		{32895, hexToBytes("80ff7f")},
-		{2113663, hexToBytes("ffff7f")}, // Max 3-byte value
-		{2113664, hexToBytes("80808000")},
-		{270549119, hexToBytes("ffffff7f")}, // Max 4-byte value
-		{270549120, hexToBytes("8080808000")},
-		{2147483647, hexToBytes("86fefefe7f")},
-		{2147483648, hexToBytes("86fefeff00")},
-		{4294967295, hexToBytes("8efefefe7f")}, // Max uint32, 5 bytes
-		// Max uint64, 10 bytes
-		{18446744073709551615, hexToBytes("80fefefefefefefefe7f")},
-	}
-
-	for _, test := range tests {
-		// Ensure the function to calculate the serialized size without
-		// actually serializing the value is calculated properly.
-		gotSize := serializeSizeVLQ(test.val)
-		if gotSize != len(test.serialized) {
-			t.Errorf("serializeSizeVLQ: did not get expected size "+
-				"for %d - got %d, want %d", test.val, gotSize,
-				len(test.serialized))
-			continue
-		}
-
-		// Ensure the value serializes to the expected bytes.
-		gotBytes := make([]byte, gotSize)
-		gotBytesWritten := putVLQ(gotBytes, test.val)
-		if !bytes.Equal(gotBytes, test.serialized) {
-			t.Errorf("putVLQUnchecked: did not get expected bytes "+
-				"for %d - got %x, want %x", test.val, gotBytes,
-				test.serialized)
-			continue
-		}
-		if gotBytesWritten != len(test.serialized) {
-			t.Errorf("putVLQUnchecked: did not get expected number "+
-				"of bytes written for %d - got %d, want %d",
-				test.val, gotBytesWritten, len(test.serialized))
-			continue
-		}
-
-		// Ensure the serialized bytes deserialize to the expected
-		// value.
-		gotVal, gotBytesRead := deserializeVLQ(test.serialized)
-		if gotVal != test.val {
-			t.Errorf("deserializeVLQ: did not get expected value "+
-				"for %x - got %d, want %d", test.serialized,
-				gotVal, test.val)
-			continue
-		}
-		if gotBytesRead != len(test.serialized) {
-			t.Errorf("deserializeVLQ: did not get expected number "+
-				"of bytes read for %d - got %d, want %d",
-				test.serialized, gotBytesRead,
-				len(test.serialized))
-			continue
-		}
-	}
-}
-
-// TestScriptCompression ensures the domain-specific script compression and
-// decompression works as expected.
-func TestScriptCompression(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name         string
-		uncompressed []byte
-		compressed   []byte
-	}{
-		{
-			name:         "nil",
-			uncompressed: nil,
-			compressed:   hexToBytes("06"),
-		},
-		{
-			name:         "pay-to-pubkey-hash 1",
-			uncompressed: hexToBytes("76a9141018853670f9f3b0582c5b9ee8ce93764ac32b9388ac"),
-			compressed:   hexToBytes("001018853670f9f3b0582c5b9ee8ce93764ac32b93"),
-		},
-		{
-			name:         "pay-to-pubkey-hash 2",
-			uncompressed: hexToBytes("76a914e34cce70c86373273efcc54ce7d2a491bb4a0e8488ac"),
-			compressed:   hexToBytes("00e34cce70c86373273efcc54ce7d2a491bb4a0e84"),
-		},
-		{
-			name:         "pay-to-script-hash 1",
-			uncompressed: hexToBytes("a914da1745e9b549bd0bfa1a569971c77eba30cd5a4b87"),
-			compressed:   hexToBytes("01da1745e9b549bd0bfa1a569971c77eba30cd5a4b"),
-		},
-		{
-			name:         "pay-to-script-hash 2",
-			uncompressed: hexToBytes("a914f815b036d9bbbce5e9f2a00abd1bf3dc91e9551087"),
-			compressed:   hexToBytes("01f815b036d9bbbce5e9f2a00abd1bf3dc91e95510"),
-		},
-		{
-			name:         "pay-to-pubkey compressed 0x02",
-			uncompressed: hexToBytes("2102192d74d0cb94344c9569c2e77901573d8d7903c3ebec3a957724895dca52c6b4ac"),
-			compressed:   hexToBytes("02192d74d0cb94344c9569c2e77901573d8d7903c3ebec3a957724895dca52c6b4"),
-		},
-		{
-			name:         "pay-to-pubkey compressed 0x03",
-			uncompressed: hexToBytes("2103b0bd634234abbb1ba1e986e884185c61cf43e001f9137f23c2c409273eb16e65ac"),
-			compressed:   hexToBytes("03b0bd634234abbb1ba1e986e884185c61cf43e001f9137f23c2c409273eb16e65"),
-		},
-		{
-			name:         "pay-to-pubkey uncompressed 0x04 even",
-			uncompressed: hexToBytes("4104192d74d0cb94344c9569c2e77901573d8d7903c3ebec3a957724895dca52c6b40d45264838c0bd96852662ce6a847b197376830160c6d2eb5e6a4c44d33f453eac"),
-			compressed:   hexToBytes("04192d74d0cb94344c9569c2e77901573d8d7903c3ebec3a957724895dca52c6b4"),
-		},
-		{
-			name:         "pay-to-pubkey uncompressed 0x04 odd",
-			uncompressed: hexToBytes("410411db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5cb2e0eaddfb84ccf9744464f82e160bfa9b8b64f9d4c03f999b8643f656b412a3ac"),
-			compressed:   hexToBytes("0511db93e1dcdb8a016b49840f8c53bc1eb68a382e97b1482ecad7b148a6909a5c"),
-		},
-		{
-			name:         "pay-to-pubkey invalid pubkey",
-			uncompressed: hexToBytes("3302aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac"),
-			compressed:   hexToBytes("293302aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaac"),
-		},
-		{
-			name:         "requires 2 size bytes - data push 200 bytes",
-			uncompressed: append(hexToBytes("4cc8"), bytes.Repeat([]byte{0x00}, 200)...),
-			// [0x80, 0x50] = 208 as a variable length quantity
-			// [0x4c, 0xc8] = OP_PUSHDATA1 200
-			compressed: append(hexToBytes("80504cc8"), bytes.Repeat([]byte{0x00}, 200)...),
-		},
-	}
-
-	for _, test := range tests {
-		// Ensure the function to calculate the serialized size without
-		// actually serializing the value is calculated properly.
-		gotSize := compressedScriptSize(test.uncompressed)
-		if gotSize != len(test.compressed) {
-			t.Errorf("compressedScriptSize (%s): did not get "+
-				"expected size - got %d, want %d", test.name,
-				gotSize, len(test.compressed))
-			continue
-		}
-
-		// Ensure the script compresses to the expected bytes.
-		gotCompressed := make([]byte, gotSize)
-		gotBytesWritten := putCompressedScript(gotCompressed,
-			test.uncompressed)
-		if !bytes.Equal(gotCompressed, test.compressed) {
-			t.Errorf("putCompressedScript (%s): did not get "+
-				"expected bytes - got %x, want %x", test.name,
-				gotCompressed, test.compressed)
-			continue
-		}
-		if gotBytesWritten != len(test.compressed) {
-			t.Errorf("putCompressedScript (%s): did not get "+
-				"expected number of bytes written - got %d, "+
-				"want %d", test.name, gotBytesWritten,
-				len(test.compressed))
-			continue
-		}
-
-		// Ensure the compressed script size is properly decoded from
-		// the compressed script.
-		gotDecodedSize := decodeCompressedScriptSize(test.compressed)
-		if gotDecodedSize != len(test.compressed) {
-			t.Errorf("decodeCompressedScriptSize (%s): did not get "+
-				"expected size - got %d, want %d", test.name,
-				gotDecodedSize, len(test.compressed))
-			continue
-		}
-
-		// Ensure the script decompresses to the expected bytes.
-		gotDecompressed := decompressScript(test.compressed)
-		if !bytes.Equal(gotDecompressed, test.uncompressed) {
-			t.Errorf("decompressScript (%s): did not get expected "+
-				"bytes - got %x, want %x", test.name,
-				gotDecompressed, test.uncompressed)
-			continue
-		}
-	}
-}
-
-// TestScriptCompressionErrors ensures calling various functions related to
-// script compression with incorrect data returns the expected results.
-func TestScriptCompressionErrors(t *testing.T) {
-	t.Parallel()
-
-	// A nil script must result in a decoded size of 0.
-	if gotSize := decodeCompressedScriptSize(nil); gotSize != 0 {
-		t.Fatalf("decodeCompressedScriptSize with nil script did not "+
-			"return 0 - got %d", gotSize)
-	}
-
-	// A nil script must result in a nil decompressed script.
-	if gotScript := decompressScript(nil); gotScript != nil {
-		t.Fatalf("decompressScript with nil script did not return nil "+
-			"decompressed script - got %x", gotScript)
-	}
-
-	// A compressed script for a pay-to-pubkey (uncompressed) that results
-	// in an invalid pubkey must result in a nil decompressed script.
-	compressedScript := hexToBytes("04012d74d0cb94344c9569c2e77901573d8d" +
-		"7903c3ebec3a957724895dca52c6b4")
-	if gotScript := decompressScript(compressedScript); gotScript != nil {
-		t.Fatalf("decompressScript with compressed pay-to-"+
-			"uncompressed-pubkey that is invalid did not return "+
-			"nil decompressed script - got %x", gotScript)
-	}
-}
-
-// TestAmountCompression ensures the domain-specific transaction output amount
-// compression and decompression works as expected.
-func TestAmountCompression(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name         string
-		uncompressed uint64
-		compressed   uint64
-	}{
-		{
-			name:         "0 KAS",
-			uncompressed: 0,
-			compressed:   0,
-		},
-		{
-			name:         "546 Sompi (current network dust value)",
-			uncompressed: 546,
-			compressed:   4911,
-		},
-		{
-			name:         "0.00001 KAS (typical transaction fee)",
-			uncompressed: 1000,
-			compressed:   4,
-		},
-		{
-			name:         "0.0001 KAS (typical transaction fee)",
-			uncompressed: 10000,
-			compressed:   5,
-		},
-		{
-			name:         "0.12345678 KAS",
-			uncompressed: 12345678,
-			compressed:   111111101,
-		},
-		{
-			name:         "0.5 KAS",
-			uncompressed: 50000000,
-			compressed:   48,
-		},
-		{
-			name:         "1 KAS",
-			uncompressed: 100000000,
-			compressed:   9,
-		},
-		{
-			name:         "5 KAS",
-			uncompressed: 500000000,
-			compressed:   49,
-		},
-		{
-			name:         "21000000 KAS (max minted coins)",
-			uncompressed: 2100000000000000,
-			compressed:   21000000,
-		},
-	}
-
-	for _, test := range tests {
-		// Ensure the amount compresses to the expected value.
-		gotCompressed := compressTxOutAmount(test.uncompressed)
-		if gotCompressed != test.compressed {
-			t.Errorf("compressTxOutAmount (%s): did not get "+
-				"expected value - got %d, want %d", test.name,
-				gotCompressed, test.compressed)
-			continue
-		}
-
-		// Ensure the value decompresses to the expected value.
-		gotDecompressed := decompressTxOutAmount(test.compressed)
-		if gotDecompressed != test.uncompressed {
-			t.Errorf("decompressTxOutAmount (%s): did not get "+
-				"expected value - got %d, want %d", test.name,
-				gotDecompressed, test.uncompressed)
-			continue
-		}
-	}
-}
-
-// TestCompressedTxOut ensures the transaction output serialization and
-// deserialization works as expected.
-func TestCompressedTxOut(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name         string
-		amount       uint64
-		scriptPubKey []byte
-		compressed   []byte
-	}{
-		{
-			name:         "pay-to-pubkey-hash dust",
-			amount:       546,
-			scriptPubKey: hexToBytes("76a9141018853670f9f3b0582c5b9ee8ce93764ac32b9388ac"),
-			compressed:   hexToBytes("a52f001018853670f9f3b0582c5b9ee8ce93764ac32b93"),
-		},
-		{
-			name:         "pay-to-pubkey uncompressed 1 KAS",
-			amount:       100000000,
-			scriptPubKey: hexToBytes("4104192d74d0cb94344c9569c2e77901573d8d7903c3ebec3a957724895dca52c6b40d45264838c0bd96852662ce6a847b197376830160c6d2eb5e6a4c44d33f453eac"),
-			compressed:   hexToBytes("0904192d74d0cb94344c9569c2e77901573d8d7903c3ebec3a957724895dca52c6b4"),
-		},
-	}
-
-	for _, test := range tests {
-		// Ensure the function to calculate the serialized size without
-		// actually serializing the txout is calculated properly.
-		gotSize := compressedTxOutSize(test.amount, test.scriptPubKey)
-		if gotSize != len(test.compressed) {
-			t.Errorf("compressedTxOutSize (%s): did not get "+
-				"expected size - got %d, want %d", test.name,
-				gotSize, len(test.compressed))
-			continue
-		}
-
-		// Ensure the txout compresses to the expected value.
-		gotCompressed := make([]byte, gotSize)
-		gotBytesWritten := putCompressedTxOut(gotCompressed,
-			test.amount, test.scriptPubKey)
-		if !bytes.Equal(gotCompressed, test.compressed) {
-			t.Errorf("compressTxOut (%s): did not get expected "+
-				"bytes - got %x, want %x", test.name,
-				gotCompressed, test.compressed)
-			continue
-		}
-		if gotBytesWritten != len(test.compressed) {
-			t.Errorf("compressTxOut (%s): did not get expected "+
-				"number of bytes written - got %d, want %d",
-				test.name, gotBytesWritten,
-				len(test.compressed))
-			continue
-		}
-
-		// Ensure the serialized bytes are decoded back to the expected
-		// uncompressed values.
-		gotAmount, gotScript, gotBytesRead, err := decodeCompressedTxOut(
-			test.compressed)
-		if err != nil {
-			t.Errorf("decodeCompressedTxOut (%s): unexpected "+
-				"error: %v", test.name, err)
-			continue
-		}
-		if gotAmount != test.amount {
-			t.Errorf("decodeCompressedTxOut (%s): did not get "+
-				"expected amount - got %d, want %d",
-				test.name, gotAmount, test.amount)
-			continue
-		}
-		if !bytes.Equal(gotScript, test.scriptPubKey) {
-			t.Errorf("decodeCompressedTxOut (%s): did not get "+
-				"expected script - got %x, want %x",
-				test.name, gotScript, test.scriptPubKey)
-			continue
-		}
-		if gotBytesRead != len(test.compressed) {
-			t.Errorf("decodeCompressedTxOut (%s): did not get "+
-				"expected number of bytes read - got %d, want %d",
-				test.name, gotBytesRead, len(test.compressed))
-			continue
-		}
-	}
-}
-
-// TestTxOutCompressionErrors ensures calling various functions related to
-// txout compression with incorrect data returns the expected results.
-func TestTxOutCompressionErrors(t *testing.T) {
-	t.Parallel()
-
-	// A compressed txout with missing compressed script must error.
-	compressedTxOut := hexToBytes("00")
-	_, _, _, err := decodeCompressedTxOut(compressedTxOut)
-	if !isDeserializeErr(err) {
-		t.Fatalf("decodeCompressedTxOut with missing compressed script "+
-			"did not return expected error type - got %T, want "+
-			"errDeserialize", err)
-	}
-
-	// A compressed txout with short compressed script must error.
-	compressedTxOut = hexToBytes("0010")
-	_, _, _, err = decodeCompressedTxOut(compressedTxOut)
-	if !isDeserializeErr(err) {
-		t.Fatalf("decodeCompressedTxOut with short compressed script "+
-			"did not return expected error type - got %T, want "+
-			"errDeserialize", err)
-	}
-}

blockdag/dag.go

@@ -6,6 +6,7 @@ package blockdag
 
 import (
 	"fmt"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"math"
 	"sort"
 	"sync"
@@ -15,8 +16,8 @@ import (
 
 	"github.com/kaspanet/kaspad/util/subnetworkid"
 
+	"github.com/kaspanet/go-secp256k1"
 	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
 	"github.com/kaspanet/kaspad/txscript"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/util/daghash"
@@ -59,9 +60,8 @@ type BlockDAG struct {
 	// The following fields are set when the instance is created and can't
 	// be changed afterwards, so there is no need to protect them with a
 	// separate mutex.
-	db           database.DB
 	dagParams    *dagconfig.Params
-	timeSource   MedianTimeSource
+	timeSource   TimeSource
 	sigCache     *txscript.SigCache
 	indexManager IndexManager
 	genesis      *blockNode
@@ -150,9 +150,9 @@ type BlockDAG struct {
 
 	lastFinalityPoint *blockNode
 
-	SubnetworkStore   *SubnetworkStore
 	utxoDiffStore     *utxoDiffStore
 	reachabilityStore *reachabilityStore
+	multisetStore     *multisetStore
 }
 
 // IsKnownBlock returns whether or not the DAG instance has the block represented
@@ -486,25 +486,24 @@ func (dag *BlockDAG) addBlock(node *blockNode,
 	if err != nil {
 		if errors.As(err, &RuleError{}) {
 			dag.index.SetStatusFlags(node, statusValidateFailed)
-		} else {
-			return nil, err
-		}
-	} else {
-		dag.blockCount++
-	}
 
-	// Intentionally ignore errors writing updated node status to DB. If
-	// it fails to write, it's not the end of the world. If the block is
-	// invalid, the worst that can happen is we revalidate the block
-	// after a restart.
-	if writeErr := dag.index.flushToDB(); writeErr != nil {
-		log.Warnf("Error flushing block index changes to disk: %s",
-			writeErr)
-	}
-	// If dag.connectBlock returned a rule error, return it here after updating DB
-	if err != nil {
+			dbTx, err := dbaccess.NewTx()
+			if err != nil {
+				return nil, err
+			}
+			defer dbTx.RollbackUnlessClosed()
+			err = dag.index.flushToDB(dbTx)
+			if err != nil {
+				return nil, err
+			}
+			err = dbTx.Commit()
+			if err != nil {
+				return nil, err
+			}
+		}
 		return nil, err
 	}
+	dag.blockCount++
 	return chainUpdates, nil
 }
 
@@ -571,14 +570,13 @@ func (dag *BlockDAG) connectBlock(node *blockNode,
 		return nil, err
 	}
 
-	newBlockUTXO, txsAcceptanceData, newBlockFeeData, err := node.verifyAndBuildUTXO(dag, block.Transactions(), fastAdd)
+	newBlockUTXO, txsAcceptanceData, newBlockFeeData, newBlockMultiSet, err := node.verifyAndBuildUTXO(dag, block.Transactions(), fastAdd)
 	if err != nil {
-		newErrString := fmt.Sprintf("error verifying UTXO for %s: %s", node, err)
 		var ruleErr RuleError
 		if ok := errors.As(err, &ruleErr); ok {
-			return nil, ruleError(ruleErr.ErrorCode, newErrString)
+			return nil, ruleError(ruleErr.ErrorCode, fmt.Sprintf("error verifying UTXO for %s: %s", node, err))
 		}
-		return nil, errors.New(newErrString)
+		return nil, errors.Wrapf(err, "error verifying UTXO for %s", node)
 	}
 
 	err = node.validateCoinbaseTransaction(dag, block, txsAcceptanceData)
@@ -587,7 +585,7 @@ func (dag *BlockDAG) connectBlock(node *blockNode,
 	}
 
 	// Apply all changes to the DAG.
-	virtualUTXODiff, virtualTxsAcceptanceData, chainUpdates, err := dag.applyDAGChanges(node, newBlockUTXO, selectedParentAnticone)
+	virtualUTXODiff, chainUpdates, err := dag.applyDAGChanges(node, newBlockUTXO, newBlockMultiSet, selectedParentAnticone)
 	if err != nil {
 		// Since all validation logic has already ran, if applyDAGChanges errors out,
 		// this means we have a problem in the internal structure of the DAG - a problem which is
@@ -596,7 +594,7 @@ func (dag *BlockDAG) connectBlock(node *blockNode,
 		panic(err)
 	}
 
-	err = dag.saveChangesFromBlock(block, virtualUTXODiff, txsAcceptanceData, virtualTxsAcceptanceData, newBlockFeeData)
+	err = dag.saveChangesFromBlock(block, virtualUTXODiff, txsAcceptanceData, newBlockFeeData)
 	if err != nil {
 		return nil, err
 	}
@@ -604,77 +602,207 @@ func (dag *BlockDAG) connectBlock(node *blockNode,
 	return chainUpdates, nil
 }
 
-func (dag *BlockDAG) saveChangesFromBlock(block *util.Block, virtualUTXODiff *UTXODiff,
-	txsAcceptanceData MultiBlockTxsAcceptanceData, virtualTxsAcceptanceData MultiBlockTxsAcceptanceData,
-	feeData compactFeeData) error {
-
-	// Write any block status changes to DB before updating the DAG state.
-	err := dag.index.flushToDB()
+// calcMultiset returns the multiset of the UTXO of the given block with the given transactions.
+func (node *blockNode) calcMultiset(dag *BlockDAG, transactions []*util.Tx, acceptanceData MultiBlockTxsAcceptanceData, selectedParentUTXO, pastUTXO UTXOSet) (*secp256k1.MultiSet, error) {
+	ms, err := node.pastUTXOMultiSet(dag, acceptanceData, selectedParentUTXO)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
-	// Atomically insert info into the database.
-	err = dag.db.Update(func(dbTx database.Tx) error {
-		err := dag.utxoDiffStore.flushToDB(dbTx)
+	for _, tx := range transactions {
+		ms, err = addTxToMultiset(ms, tx.MsgTx(), pastUTXO, UnacceptedBlueScore)
 		if err != nil {
-			return err
+			return nil, err
 		}
+	}
 
-		err = dag.reachabilityStore.flushToDB(dbTx)
-		if err != nil {
-			return err
-		}
+	return ms, nil
+}
 
-		// Update best block state.
-		state := &dagState{
-			TipHashes:         dag.TipHashes(),
-			LastFinalityPoint: dag.lastFinalityPoint.hash,
-		}
-		err = dbPutDAGState(dbTx, state)
-		if err != nil {
-			return err
-		}
+// acceptedSelectedParentMultiset takes the multiset of the selected
+// parent, replaces all the selected parent outputs' blue score with
+// the block blue score and returns the result.
+func (node *blockNode) acceptedSelectedParentMultiset(dag *BlockDAG,
+	acceptanceData MultiBlockTxsAcceptanceData) (*secp256k1.MultiSet, error) {
 
-		// Update the UTXO set using the diffSet that was melded into the
-		// full UTXO set.
-		err = dbPutUTXODiff(dbTx, virtualUTXODiff)
-		if err != nil {
-			return err
-		}
+	if node.isGenesis() {
+		return secp256k1.NewMultiset(), nil
+	}
 
-		// Scan all accepted transactions and register any subnetwork registry
-		// transaction. If any subnetwork registry transaction is not well-formed,
-		// fail the entire block.
-		err = registerSubnetworks(dbTx, block.Transactions())
-		if err != nil {
-			return err
-		}
+	ms, err := dag.multisetStore.multisetByBlockNode(node.selectedParent)
+	if err != nil {
+		return nil, err
+	}
 
-		blockID, err := createBlockID(dbTx, block.Hash())
-		if err != nil {
-			return err
-		}
+	selectedParentAcceptanceData, exists := acceptanceData.FindAcceptanceData(node.selectedParent.hash)
+	if !exists {
+		return nil, errors.Errorf("couldn't find selected parent acceptance data for block %s", node)
+	}
+	for _, txAcceptanceData := range selectedParentAcceptanceData.TxAcceptanceData {
+		tx := txAcceptanceData.Tx
+		msgTx := tx.MsgTx()
+		isCoinbase := tx.IsCoinBase()
+		for i, txOut := range msgTx.TxOut {
+			outpoint := *wire.NewOutpoint(tx.ID(), uint32(i))
 
-		// Allow the index manager to call each of the currently active
-		// optional indexes with the block being connected so they can
-		// update themselves accordingly.
-		if dag.indexManager != nil {
-			err := dag.indexManager.ConnectBlock(dbTx, block, blockID, dag, txsAcceptanceData, virtualTxsAcceptanceData)
+			unacceptedEntry := NewUTXOEntry(txOut, isCoinbase, UnacceptedBlueScore)
+			acceptedEntry := NewUTXOEntry(txOut, isCoinbase, node.blueScore)
+
+			var err error
+			ms, err = removeUTXOFromMultiset(ms, unacceptedEntry, &outpoint)
 			if err != nil {
-				return err
+				return nil, err
+			}
+
+			ms, err = addUTXOToMultiset(ms, acceptedEntry, &outpoint)
+			if err != nil {
+				return nil, err
 			}
 		}
+	}
 
-		// Apply the fee data into the database
-		return dbStoreFeeData(dbTx, block.Hash(), feeData)
-	})
+	return ms, nil
+}
+
+func (node *blockNode) pastUTXOMultiSet(dag *BlockDAG, acceptanceData MultiBlockTxsAcceptanceData, selectedParentUTXO UTXOSet) (*secp256k1.MultiSet, error) {
+	ms, err := node.acceptedSelectedParentMultiset(dag, acceptanceData)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, blockAcceptanceData := range acceptanceData {
+		if blockAcceptanceData.BlockHash.IsEqual(node.selectedParent.hash) {
+			continue
+		}
+
+		for _, txAcceptanceData := range blockAcceptanceData.TxAcceptanceData {
+			if !txAcceptanceData.IsAccepted {
+				continue
+			}
+
+			tx := txAcceptanceData.Tx.MsgTx()
+
+			var err error
+			ms, err = addTxToMultiset(ms, tx, selectedParentUTXO, node.blueScore)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+	return ms, nil
+}
+
+func addTxToMultiset(ms *secp256k1.MultiSet, tx *wire.MsgTx, pastUTXO UTXOSet, blockBlueScore uint64) (*secp256k1.MultiSet, error) {
+	isCoinbase := tx.IsCoinBase()
+	if !isCoinbase {
+		for _, txIn := range tx.TxIn {
+			entry, ok := pastUTXO.Get(txIn.PreviousOutpoint)
+			if !ok {
+				return nil, errors.Errorf("Couldn't find entry for outpoint %s", txIn.PreviousOutpoint)
+			}
+
+			var err error
+			ms, err = removeUTXOFromMultiset(ms, entry, &txIn.PreviousOutpoint)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	for i, txOut := range tx.TxOut {
+		outpoint := *wire.NewOutpoint(tx.TxID(), uint32(i))
+		entry := NewUTXOEntry(txOut, isCoinbase, blockBlueScore)
+
+		var err error
+		ms, err = addUTXOToMultiset(ms, entry, &outpoint)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return ms, nil
+}
+
+func (dag *BlockDAG) saveChangesFromBlock(block *util.Block, virtualUTXODiff *UTXODiff,
+	txsAcceptanceData MultiBlockTxsAcceptanceData, feeData compactFeeData) error {
+
+	dbTx, err := dbaccess.NewTx()
 	if err != nil {
 		return err
 	}
+	defer dbTx.RollbackUnlessClosed()
+
+	err = dag.index.flushToDB(dbTx)
+	if err != nil {
+		return err
+	}
+
+	err = dag.utxoDiffStore.flushToDB(dbTx)
+	if err != nil {
+		return err
+	}
+
+	err = dag.reachabilityStore.flushToDB(dbTx)
+	if err != nil {
+		return err
+	}
+
+	err = dag.multisetStore.flushToDB(dbTx)
+	if err != nil {
+		return err
+	}
+
+	// Update DAG state.
+	state := &dagState{
+		TipHashes:         dag.TipHashes(),
+		LastFinalityPoint: dag.lastFinalityPoint.hash,
+		LocalSubnetworkID: dag.subnetworkID,
+	}
+	err = saveDAGState(dbTx, state)
+	if err != nil {
+		return err
+	}
+
+	// Update the UTXO set using the diffSet that was melded into the
+	// full UTXO set.
+	err = updateUTXOSet(dbTx, virtualUTXODiff)
+	if err != nil {
+		return err
+	}
+
+	// Scan all accepted transactions and register any subnetwork registry
+	// transaction. If any subnetwork registry transaction is not well-formed,
+	// fail the entire block.
+	err = registerSubnetworks(dbTx, block.Transactions())
+	if err != nil {
+		return err
+	}
+
+	// Allow the index manager to call each of the currently active
+	// optional indexes with the block being connected so they can
+	// update themselves accordingly.
+	if dag.indexManager != nil {
+		err := dag.indexManager.ConnectBlock(dbTx, block.Hash(), txsAcceptanceData)
+		if err != nil {
+			return err
+		}
+	}
+
+	// Apply the fee data into the database
+	err = dbaccess.StoreFeeData(dbTx, block.Hash(), feeData)
+	if err != nil {
+		return err
+	}
+
+	err = dbTx.Commit()
+	if err != nil {
+		return err
+	}
+
 	dag.index.clearDirtyEntries()
 	dag.utxoDiffStore.clearDirtyEntries()
 	dag.reachabilityStore.clearDirtyEntries()
+	dag.multisetStore.clearNewEntries()
+
 	return nil
 }
 
@@ -698,7 +826,7 @@ func (dag *BlockDAG) validateGasLimit(block *util.Block) error {
 		if !msgTx.SubnetworkID.IsEqual(currentSubnetworkID) {
 			currentSubnetworkID = &msgTx.SubnetworkID
 			currentGasUsage = 0
-			currentSubnetworkGasLimit, err = dag.SubnetworkStore.GasLimit(currentSubnetworkID)
+			currentSubnetworkGasLimit, err = GasLimit(currentSubnetworkID)
 			if err != nil {
 				return errors.Errorf("Error getting gas limit for subnetworkID '%s': %s", currentSubnetworkID, err)
 			}
@@ -796,9 +924,7 @@ func (dag *BlockDAG) finalizeNodesBelowFinalityPoint(deleteDiffData bool) {
 		}
 	}
 	if deleteDiffData {
-		err := dag.db.Update(func(dbTx database.Tx) error {
-			return dag.utxoDiffStore.removeBlocksDiffData(dbTx, blockHashesToDelete)
-		})
+		err := dag.utxoDiffStore.removeBlocksDiffData(dbaccess.NoTx(), blockHashesToDelete)
 		if err != nil {
 			panic(fmt.Sprintf("Error removing diff data from utxoDiffStore: %s", err))
 		}
@@ -851,7 +977,7 @@ func (dag *BlockDAG) NextAcceptedIDMerkleRootNoLock() (*daghash.Hash, error) {
 //
 // This function MUST be called with the DAG read-lock held
 func (dag *BlockDAG) TxsAcceptedByVirtual() (MultiBlockTxsAcceptanceData, error) {
-	_, txsAcceptanceData, err := dag.pastUTXO(&dag.virtual.blockNode)
+	_, _, txsAcceptanceData, err := dag.pastUTXO(&dag.virtual.blockNode)
 	return txsAcceptanceData, err
 }
 
@@ -863,7 +989,7 @@ func (dag *BlockDAG) TxsAcceptedByBlockHash(blockHash *daghash.Hash) (MultiBlock
 	if node == nil {
 		return nil, errors.Errorf("Couldn't find block %s", blockHash)
 	}
-	_, txsAcceptanceData, err := dag.pastUTXO(node)
+	_, _, txsAcceptanceData, err := dag.pastUTXO(node)
 	return txsAcceptanceData, err
 }
 
@@ -874,38 +1000,40 @@ func (dag *BlockDAG) TxsAcceptedByBlockHash(blockHash *daghash.Hash) (MultiBlock
 // 4. Updates each of the tips' utxoDiff.
 // 5. Applies the new virtual's blue score to all the unaccepted UTXOs
 // 6. Adds the block to the reachability structures
-// 7. Updates the finality point of the DAG (if required).
+// 7. Adds the multiset of the block to the multiset store.
+// 8. Updates the finality point of the DAG (if required).
 //
 // It returns the diff in the virtual block's UTXO set.
 //
 // This function MUST be called with the DAG state lock held (for writes).
-func (dag *BlockDAG) applyDAGChanges(node *blockNode, newBlockUTXO UTXOSet, selectedParentAnticone []*blockNode) (
-	virtualUTXODiff *UTXODiff, virtualTxsAcceptanceData MultiBlockTxsAcceptanceData,
-	chainUpdates *chainUpdates, err error) {
+func (dag *BlockDAG) applyDAGChanges(node *blockNode, newBlockUTXO UTXOSet, newBlockMultiset *secp256k1.MultiSet, selectedParentAnticone []*blockNode) (
+	virtualUTXODiff *UTXODiff, chainUpdates *chainUpdates, err error) {
 
 	// Add the block to the reachability structures
 	err = dag.updateReachability(node, selectedParentAnticone)
 	if err != nil {
-		return nil, nil, nil, errors.Wrap(err, "failed updating reachability")
+		return nil, nil, errors.Wrap(err, "failed updating reachability")
 	}
 
+	dag.multisetStore.setMultiset(node, newBlockMultiset)
+
 	if err = node.updateParents(dag, newBlockUTXO); err != nil {
-		return nil, nil, nil, errors.Wrapf(err, "failed updating parents of %s", node)
+		return nil, nil, errors.Wrapf(err, "failed updating parents of %s", node)
 	}
 
 	// Update the virtual block's parents (the DAG tips) to include the new block.
 	chainUpdates = dag.virtual.AddTip(node)
 
 	// Build a UTXO set for the new virtual block
-	newVirtualUTXO, virtualTxsAcceptanceData, err := dag.pastUTXO(&dag.virtual.blockNode)
+	newVirtualUTXO, _, _, err := dag.pastUTXO(&dag.virtual.blockNode)
 	if err != nil {
-		return nil, nil, nil, errors.Wrap(err, "could not restore past UTXO for virtual")
+		return nil, nil, errors.Wrap(err, "could not restore past UTXO for virtual")
 	}
 
 	// Apply new utxoDiffs to all the tips
 	err = updateTipsUTXO(dag, newVirtualUTXO)
 	if err != nil {
-		return nil, nil, nil, errors.Wrap(err, "failed updating the tips' UTXO")
+		return nil, nil, errors.Wrap(err, "failed updating the tips' UTXO")
 	}
 
 	// It is now safe to meld the UTXO set to base.
@@ -913,7 +1041,7 @@ func (dag *BlockDAG) applyDAGChanges(node *blockNode, newBlockUTXO UTXOSet, sele
 	virtualUTXODiff = diffSet.UTXODiff
 	err = dag.meldVirtualUTXO(diffSet)
 	if err != nil {
-		return nil, nil, nil, errors.Wrap(err, "failed melding the virtual UTXO")
+		return nil, nil, errors.Wrap(err, "failed melding the virtual UTXO")
 	}
 
 	dag.index.SetStatusFlags(node, statusValid)
@@ -921,7 +1049,7 @@ func (dag *BlockDAG) applyDAGChanges(node *blockNode, newBlockUTXO UTXOSet, sele
 	// And now we can update the finality point of the DAG (if required)
 	dag.updateFinalityPoint()
 
-	return virtualUTXODiff, virtualTxsAcceptanceData, chainUpdates, nil
+	return virtualUTXODiff, chainUpdates, nil
 }
 
 func (dag *BlockDAG) meldVirtualUTXO(newVirtualUTXODiffSet *DiffUTXOSet) error {
@@ -948,42 +1076,49 @@ func (node *blockNode) diffFromTxs(pastUTXO UTXOSet, transactions []*util.Tx) (*
 }
 
 // verifyAndBuildUTXO verifies all transactions in the given block and builds its UTXO
-// to save extra traversals it returns the transactions acceptance data and the compactFeeData for the new block
+// to save extra traversals it returns the transactions acceptance data, the compactFeeData
+// for the new block and its multiset.
 func (node *blockNode) verifyAndBuildUTXO(dag *BlockDAG, transactions []*util.Tx, fastAdd bool) (
-	newBlockUTXO UTXOSet, txsAcceptanceData MultiBlockTxsAcceptanceData, newBlockFeeData compactFeeData, err error) {
+	newBlockUTXO UTXOSet, txsAcceptanceData MultiBlockTxsAcceptanceData, newBlockFeeData compactFeeData, multiset *secp256k1.MultiSet, err error) {
 
-	pastUTXO, txsAcceptanceData, err := dag.pastUTXO(node)
+	pastUTXO, selectedParentUTXO, txsAcceptanceData, err := dag.pastUTXO(node)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, nil, nil, err
 	}
 
 	err = node.validateAcceptedIDMerkleRoot(dag, txsAcceptanceData)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, nil, nil, err
 	}
 
 	feeData, err := dag.checkConnectToPastUTXO(node, pastUTXO, transactions, fastAdd)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, nil, nil, err
 	}
 
 	diffFromTxs, err := node.diffFromTxs(pastUTXO, transactions)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, nil, nil, err
 	}
 	utxo, err := pastUTXO.WithDiff(diffFromTxs)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, nil, nil, err
 	}
 
-	calculatedMultisetHash := utxo.Multiset().Hash()
+	multiset, err = node.calcMultiset(dag, transactions, txsAcceptanceData, selectedParentUTXO, pastUTXO)
+	if err != nil {
+		return nil, nil, nil, nil, err
+	}
+
+	calculatedMultisetHash := daghash.Hash(*multiset.Finalize())
 	if !calculatedMultisetHash.IsEqual(node.utxoCommitment) {
 		str := fmt.Sprintf("block %s UTXO commitment is invalid - block "+
 			"header indicates %s, but calculated value is %s", node.hash,
 			node.utxoCommitment, calculatedMultisetHash)
-		return nil, nil, nil, ruleError(ErrBadUTXOCommitment, str)
+		return nil, nil, nil, nil, ruleError(ErrBadUTXOCommitment, str)
 	}
-	return utxo, txsAcceptanceData, feeData, nil
+
+	return utxo, txsAcceptanceData, feeData, multiset, nil
 }
 
 // TxAcceptanceData stores a transaction together with an indication
@@ -1026,21 +1161,17 @@ func genesisPastUTXO(virtual *virtualBlock) UTXOSet {
 	return genesisPastUTXO
 }
 
-func (node *blockNode) fetchBlueBlocks(db database.DB) ([]*util.Block, error) {
+func (node *blockNode) fetchBlueBlocks() ([]*util.Block, error) {
 	blueBlocks := make([]*util.Block, len(node.blues))
-	err := db.View(func(dbTx database.Tx) error {
-		for i, blueBlockNode := range node.blues {
-			blueBlock, err := dbFetchBlockByNode(dbTx, blueBlockNode)
-			if err != nil {
-				return err
-			}
-
-			blueBlocks[i] = blueBlock
+	for i, blueBlockNode := range node.blues {
+		blueBlock, err := fetchBlockByHash(dbaccess.NoTx(), blueBlockNode.hash)
+		if err != nil {
+			return nil, err
 		}
 
-		return nil
-	})
-	return blueBlocks, err
+		blueBlocks[i] = blueBlock
+	}
+	return blueBlocks, nil
 }
 
 // applyBlueBlocks adds all transactions in the blue blocks to the selectedParent's UTXO set
@@ -1137,28 +1268,33 @@ func (node *blockNode) updateParentsDiffs(dag *BlockDAG, newBlockUTXO UTXOSet) e
 // To save traversals over the blue blocks, it also returns the transaction acceptance data for
 // all blue blocks
 func (dag *BlockDAG) pastUTXO(node *blockNode) (
-	pastUTXO UTXOSet, bluesTxsAcceptanceData MultiBlockTxsAcceptanceData, err error) {
+	pastUTXO, selectedParentUTXO UTXOSet, bluesTxsAcceptanceData MultiBlockTxsAcceptanceData, err error) {
 
 	if node.isGenesis() {
-		return genesisPastUTXO(dag.virtual), MultiBlockTxsAcceptanceData{}, nil
+		return genesisPastUTXO(dag.virtual), NewFullUTXOSet(), MultiBlockTxsAcceptanceData{}, nil
 	}
-	selectedParentUTXO, err := dag.restoreUTXO(node.selectedParent)
+	selectedParentUTXO, err = dag.restoreUTXO(node.selectedParent)
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, nil, err
 	}
 
-	blueBlocks, err := node.fetchBlueBlocks(dag.db)
+	blueBlocks, err := node.fetchBlueBlocks()
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, nil, err
 	}
 
 	selectedParent := blueBlocks[0]
 	acceptedSelectedParentUTXO, selectedParentAcceptanceData, err := node.acceptSelectedParentTransactions(selectedParent, selectedParentUTXO)
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, nil, err
 	}
 
-	return node.applyBlueBlocks(acceptedSelectedParentUTXO, selectedParentAcceptanceData, blueBlocks)
+	pastUTXO, bluesTxsAcceptanceData, err = node.applyBlueBlocks(acceptedSelectedParentUTXO, selectedParentAcceptanceData, blueBlocks)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
+	return pastUTXO, selectedParentUTXO, bluesTxsAcceptanceData, nil
 }
 
 func (node *blockNode) acceptSelectedParentTransactions(selectedParent *util.Block, selectedParentUTXO UTXOSet) (acceptedSelectedParentUTXO UTXOSet, txAcceptanceData []TxAcceptanceData, err error) {
@@ -1214,8 +1350,8 @@ func (dag *BlockDAG) restoreUTXO(node *blockNode) (UTXOSet, error) {
 		if err != nil {
 			return nil, err
 		}
-		// Use WithDiffInPlace, otherwise copying the diffs again and again create a polynomial overhead
-		err = accumulatedDiff.WithDiffInPlace(diff)
+		// Use withDiffInPlace, otherwise copying the diffs again and again create a polynomial overhead
+		err = accumulatedDiff.withDiffInPlace(diff)
 		if err != nil {
 			return nil, err
 		}
@@ -1265,14 +1401,14 @@ func (dag *BlockDAG) isCurrent() bool {
 		dagTimestamp = selectedTip.timestamp
 	}
 	dagTime := time.Unix(dagTimestamp, 0)
-	return dag.AdjustedTime().Sub(dagTime) <= isDAGCurrentMaxDiff
+	return dag.Now().Sub(dagTime) <= isDAGCurrentMaxDiff
 }
 
-// AdjustedTime returns the adjusted time according to
-// dag.timeSource. See MedianTimeSource.AdjustedTime for
+// Now returns the adjusted time according to
+// dag.timeSource. See TimeSource.Now for
 // more details.
-func (dag *BlockDAG) AdjustedTime() time.Time {
-	return dag.timeSource.AdjustedTime()
+func (dag *BlockDAG) Now() time.Time {
+	return dag.timeSource.Now()
 }
 
 // IsCurrent returns whether or not the DAG believes it is current. Several
@@ -1393,11 +1529,6 @@ func (dag *BlockDAG) UTXOConfirmations(outpoint *wire.Outpoint) (uint64, bool) {
 	return confirmations, true
 }
 
-// UTXOCommitment returns a commitment to the dag's current UTXOSet
-func (dag *BlockDAG) UTXOCommitment() string {
-	return dag.UTXOSet().UTXOMultiset.Hash().String()
-}
-
 // blockConfirmations returns the current confirmations number of the given node
 // The confirmations number is defined as follows:
 // * If the node is in the selected tip red set	-> 0
@@ -1810,8 +1941,23 @@ func (dag *BlockDAG) SubnetworkID() *subnetworkid.SubnetworkID {
 	return dag.subnetworkID
 }
 
+// ForEachHash runs the given fn on every hash that's currently known to
+// the DAG.
+//
+// This function is NOT safe for concurrent access. It is meant to be
+// used either on initialization or when the dag lock is held for reads.
+func (dag *BlockDAG) ForEachHash(fn func(hash daghash.Hash) error) error {
+	for hash := range dag.index.index {
+		err := fn(hash)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func (dag *BlockDAG) addDelayedBlock(block *util.Block, delay time.Duration) error {
-	processTime := dag.AdjustedTime().Add(delay)
+	processTime := dag.Now().Add(delay)
 	log.Debugf("Adding block to delayed blocks queue (block hash: %s, process time: %s)", block.Hash().String(), processTime)
 	delayedBlock := &delayedBlock{
 		block:       block,
@@ -1829,7 +1975,7 @@ func (dag *BlockDAG) processDelayedBlocks() error {
 	// Check if the delayed block with the earliest process time should be processed
 	for dag.delayedBlocksQueue.Len() > 0 {
 		earliestDelayedBlockProcessTime := dag.peekDelayedBlock().processTime
-		if earliestDelayedBlockProcessTime.After(dag.AdjustedTime()) {
+		if earliestDelayedBlockProcessTime.After(dag.Now()) {
 			break
 		}
 		delayedBlock := dag.popDelayedBlock()
@@ -1863,25 +2009,16 @@ func (dag *BlockDAG) peekDelayedBlock() *delayedBlock {
 // connected to the DAG for the purpose of supporting optional indexes.
 type IndexManager interface {
 	// Init is invoked during DAG initialize in order to allow the index
-	// manager to initialize itself and any indexes it is managing. The
-	// channel parameter specifies a channel the caller can close to signal
-	// that the process should be interrupted. It can be nil if that
-	// behavior is not desired.
-	Init(database.DB, *BlockDAG, <-chan struct{}) error
+	// manager to initialize itself and any indexes it is managing.
+	Init(*BlockDAG) error
 
 	// ConnectBlock is invoked when a new block has been connected to the
 	// DAG.
-	ConnectBlock(dbTx database.Tx, block *util.Block, blockID uint64, dag *BlockDAG, acceptedTxsData MultiBlockTxsAcceptanceData, virtualTxsAcceptanceData MultiBlockTxsAcceptanceData) error
+	ConnectBlock(dbContext *dbaccess.TxContext, blockHash *daghash.Hash, acceptedTxsData MultiBlockTxsAcceptanceData) error
 }
 
 // Config is a descriptor which specifies the blockDAG instance configuration.
 type Config struct {
-	// DB defines the database which houses the blocks and will be used to
-	// store all metadata created by this package such as the utxo set.
-	//
-	// This field is required.
-	DB database.DB
-
 	// Interrupt specifies a channel the caller can close to signal that
 	// long running operations, such as catching up indexes or performing
 	// database migrations, should be interrupted.
@@ -1895,13 +2032,9 @@ type Config struct {
 	// This field is required.
 	DAGParams *dagconfig.Params
 
-	// TimeSource defines the median time source to use for things such as
+	// TimeSource defines the time source to use for things such as
 	// block processing and determining whether or not the DAG is current.
-	//
-	// The caller is expected to keep a reference to the time source as well
-	// and add time samples from other peers on the network so the local
-	// time is adjusted to be in agreement with other peers.
-	TimeSource MedianTimeSource
+	TimeSource TimeSource
 
 	// SigCache defines a signature cache to use when when validating
 	// signatures. This is typically most useful when individual
@@ -1929,9 +2062,6 @@ type Config struct {
 // New returns a BlockDAG instance using the provided configuration details.
 func New(config *Config) (*BlockDAG, error) {
 	// Enforce required config fields.
-	if config.DB == nil {
-		return nil, AssertError("BlockDAG.New database is nil")
-	}
 	if config.DAGParams == nil {
 		return nil, AssertError("BlockDAG.New DAG parameters nil")
 	}
@@ -1942,9 +2072,8 @@ func New(config *Config) (*BlockDAG, error) {
 	params := config.DAGParams
 	targetTimePerBlock := int64(params.TargetTimePerBlock / time.Second)
 
-	index := newBlockIndex(config.DB, params)
+	index := newBlockIndex(params)
 	dag := &BlockDAG{
-		db:                             config.DB,
 		dagParams:                      params,
 		timeSource:                     config.TimeSource,
 		sigCache:                       config.SigCache,
@@ -1961,13 +2090,13 @@ func New(config *Config) (*BlockDAG, error) {
 		warningCaches:                  newThresholdCaches(vbNumBits),
 		deploymentCaches:               newThresholdCaches(dagconfig.DefinedDeployments),
 		blockCount:                     0,
-		SubnetworkStore:                newSubnetworkStore(config.DB),
 		subnetworkID:                   config.SubnetworkID,
 	}
 
 	dag.virtual = newVirtualBlock(dag, nil)
 	dag.utxoDiffStore = newUTXODiffStore(dag)
 	dag.reachabilityStore = newReachabilityStore(dag)
+	dag.multisetStore = newMultisetStore(dag)
 
 	// Initialize the DAG state from the passed database. When the db
 	// does not yet contain any DAG state, both it and the DAG state
@@ -1976,19 +2105,11 @@ func New(config *Config) (*BlockDAG, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer func() {
-		if err != nil {
-			err := dag.removeDAGState()
-			if err != nil {
-				panic(fmt.Sprintf("Couldn't remove the DAG State: %s", err))
-			}
-		}
-	}()
 
 	// Initialize and catch up all of the currently active optional indexes
 	// as needed.
 	if config.IndexManager != nil {
-		err = config.IndexManager.Init(dag.db, dag, config.Interrupt)
+		err = config.IndexManager.Init(dag)
 		if err != nil {
 			return nil, err
 		}

blockdag/dag_test.go

@@ -6,6 +6,7 @@ package blockdag
 
 import (
 	"fmt"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/pkg/errors"
 	"os"
 	"path/filepath"
@@ -13,7 +14,6 @@ import (
 	"time"
 
 	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
 	"github.com/kaspanet/kaspad/txscript"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/util/daghash"
@@ -40,7 +40,7 @@ func TestBlockCount(t *testing.T) {
 	}
 
 	// Create a new database and DAG instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("TestBlockCount", Config{
+	dag, teardownFunc, err := DAGSetup("TestBlockCount", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
@@ -93,7 +93,7 @@ func TestIsKnownBlock(t *testing.T) {
 	}
 
 	// Create a new database and DAG instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("haveblock", Config{
+	dag, teardownFunc, err := DAGSetup("haveblock", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
@@ -204,7 +204,7 @@ func TestIsKnownBlock(t *testing.T) {
 		{hash: dagconfig.SimnetParams.GenesisHash.String(), want: true},
 
 		// Block 3b should be present (as a second child of Block 2).
-		{hash: "264176fb6072e2362db18f92d3f4b739cff071a206736df7c407c0bf9a1d7fef", want: true},
+		{hash: "216301e3fc03cf89973b9192b4ecdd732bf3b677cf1ca4f6c340a56f1533fb4f", want: true},
 
 		// Block 100000 should be present (as an orphan).
 		{hash: "65b20b048a074793ebfd1196e49341c8d194dabfc6b44a4fd0c607406e122baf", want: true},
@@ -550,18 +550,17 @@ func TestNew(t *testing.T) {
 
 	dbPath := filepath.Join(tempDir, "TestNew")
 	_ = os.RemoveAll(dbPath)
-	db, err := database.Create(testDbType, dbPath, blockDataNet)
+	err := dbaccess.Open(dbPath)
 	if err != nil {
 		t.Fatalf("error creating db: %s", err)
 	}
 	defer func() {
-		db.Close()
+		dbaccess.Close()
 		os.RemoveAll(dbPath)
 	}()
 	config := &Config{
 		DAGParams:  &dagconfig.SimnetParams,
-		DB:         db,
-		TimeSource: NewMedianTime(),
+		TimeSource: NewTimeSource(),
 		SigCache:   txscript.NewSigCache(1000),
 	}
 	_, err = New(config)
@@ -590,20 +589,19 @@ func TestAcceptingInInit(t *testing.T) {
 	// Create a test database
 	dbPath := filepath.Join(tempDir, "TestAcceptingInInit")
 	_ = os.RemoveAll(dbPath)
-	db, err := database.Create(testDbType, dbPath, blockDataNet)
+	err := dbaccess.Open(dbPath)
 	if err != nil {
 		t.Fatalf("error creating db: %s", err)
 	}
 	defer func() {
-		db.Close()
+		dbaccess.Close()
 		os.RemoveAll(dbPath)
 	}()
 
 	// Create a DAG to add the test block into
 	config := &Config{
 		DAGParams:  &dagconfig.SimnetParams,
-		DB:         db,
-		TimeSource: NewMedianTime(),
+		TimeSource: NewTimeSource(),
 		SigCache:   txscript.NewSigCache(1000),
 	}
 	dag, err := New(config)
@@ -625,16 +623,30 @@ func TestAcceptingInInit(t *testing.T) {
 	testNode.status = statusDataStored
 
 	// Manually add the test block to the database
-	err = db.Update(func(dbTx database.Tx) error {
-		err := dbStoreBlock(dbTx, testBlock)
-		if err != nil {
-			return err
-		}
-		return dbStoreBlockNode(dbTx, testNode)
-	})
+	dbTx, err := dbaccess.NewTx()
+	if err != nil {
+		t.Fatalf("Failed to open database "+
+			"transaction: %s", err)
+	}
+	defer dbTx.RollbackUnlessClosed()
+	err = storeBlock(dbTx, testBlock)
+	if err != nil {
+		t.Fatalf("Failed to store block: %s", err)
+	}
+	dbTestNode, err := serializeBlockNode(testNode)
+	if err != nil {
+		t.Fatalf("Failed to serialize blockNode: %s", err)
+	}
+	key := blockIndexKey(testNode.hash, testNode.blueScore)
+	err = dbaccess.StoreIndexBlock(dbTx, key, dbTestNode)
 	if err != nil {
 		t.Fatalf("Failed to update block index: %s", err)
 	}
+	err = dbTx.Commit()
+	if err != nil {
+		t.Fatalf("Failed to commit database "+
+			"transaction: %s", err)
+	}
 
 	// Create a new DAG. We expect this DAG to process the
 	// test node
@@ -654,7 +666,7 @@ func TestConfirmations(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
 	params := dagconfig.SimnetParams
 	params.K = 1
-	dag, teardownFunc, err := DAGSetup("TestConfirmations", Config{
+	dag, teardownFunc, err := DAGSetup("TestConfirmations", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -757,7 +769,7 @@ func TestAcceptingBlock(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
 	params := dagconfig.SimnetParams
 	params.K = 3
-	dag, teardownFunc, err := DAGSetup("TestAcceptingBlock", Config{
+	dag, teardownFunc, err := DAGSetup("TestAcceptingBlock", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -887,7 +899,7 @@ func TestFinalizeNodesBelowFinalityPoint(t *testing.T) {
 func testFinalizeNodesBelowFinalityPoint(t *testing.T, deleteDiffData bool) {
 	params := dagconfig.SimnetParams
 	params.K = 1
-	dag, teardownFunc, err := DAGSetup("testFinalizeNodesBelowFinalityPoint", Config{
+	dag, teardownFunc, err := DAGSetup("testFinalizeNodesBelowFinalityPoint", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -899,13 +911,20 @@ func testFinalizeNodesBelowFinalityPoint(t *testing.T, deleteDiffData bool) {
 	blockTime := dag.genesis.Header().Timestamp
 
 	flushUTXODiffStore := func() {
-		err := dag.db.Update(func(dbTx database.Tx) error {
-			return dag.utxoDiffStore.flushToDB(dbTx)
-		})
+		dbTx, err := dbaccess.NewTx()
+		if err != nil {
+			t.Fatalf("Failed to open database transaction: %s", err)
+		}
+		defer dbTx.RollbackUnlessClosed()
+		err = dag.utxoDiffStore.flushToDB(dbTx)
 		if err != nil {
 			t.Fatalf("Error flushing utxoDiffStore data to DB: %s", err)
 		}
 		dag.utxoDiffStore.clearDirtyEntries()
+		err = dbTx.Commit()
+		if err != nil {
+			t.Fatalf("Failed to commit database transaction: %s", err)
+		}
 	}
 
 	addNode := func(parent *blockNode) *blockNode {
@@ -946,12 +965,22 @@ func testFinalizeNodesBelowFinalityPoint(t *testing.T, deleteDiffData bool) {
 		} else if !deleteDiffData && !ok {
 			t.Errorf("The diff data of node with blue score %d shouldn't have been unloaded if deleteDiffData is %T", node.blueScore, deleteDiffData)
 		}
-		if diffData, err := dag.utxoDiffStore.diffDataFromDB(node.hash); err != nil {
+
+		_, err := dag.utxoDiffStore.diffDataFromDB(node.hash)
+		exists := !dbaccess.IsNotFoundError(err)
+		if exists && err != nil {
 			t.Errorf("diffDataFromDB: %s", err)
-		} else if deleteDiffData && diffData != nil {
+			continue
+		}
+
+		if deleteDiffData && exists {
 			t.Errorf("The diff data of node with blue score %d should have been deleted from the database if deleteDiffData is %T", node.blueScore, deleteDiffData)
-		} else if !deleteDiffData && diffData == nil {
+			continue
+		}
+
+		if !deleteDiffData && !exists {
 			t.Errorf("The diff data of node with blue score %d shouldn't have been deleted from the database if deleteDiffData is %T", node.blueScore, deleteDiffData)
+			continue
 		}
 	}
 
@@ -972,7 +1001,7 @@ func testFinalizeNodesBelowFinalityPoint(t *testing.T, deleteDiffData bool) {
 
 func TestDAGIndexFailedStatus(t *testing.T) {
 	params := dagconfig.SimnetParams
-	dag, teardownFunc, err := DAGSetup("TestDAGIndexFailedStatus", Config{
+	dag, teardownFunc, err := DAGSetup("TestDAGIndexFailedStatus", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {

blockdag/dagio.go

@@ -9,63 +9,22 @@ import (
 	"encoding/binary"
 	"encoding/json"
 	"fmt"
-	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/pkg/errors"
 	"io"
 	"sync"
 
-	"github.com/kaspanet/kaspad/database"
+	"github.com/kaspanet/kaspad/dagconfig"
+	"github.com/kaspanet/kaspad/dbaccess"
+	"github.com/pkg/errors"
+
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/util/binaryserializer"
+	"github.com/kaspanet/kaspad/util/buffers"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/util/subnetworkid"
 	"github.com/kaspanet/kaspad/wire"
 )
 
-const (
-	// blockHdrSize is the size of a block header. This is simply the
-	// constant from wire and is only provided here for convenience since
-	// wire.MaxBlockHeaderPayload is quite long.
-	blockHdrSize = wire.MaxBlockHeaderPayload
-
-	// latestUTXOSetBucketVersion is the current version of the UTXO set
-	// bucket that is used to track all unspent outputs.
-	latestUTXOSetBucketVersion = 1
-)
-
 var (
-	// blockIndexBucketName is the name of the database bucket used to house the
-	// block headers and contextual information.
-	blockIndexBucketName = []byte("blockheaderidx")
-
-	// dagStateKeyName is the name of the db key used to store the DAG
-	// tip hashes.
-	dagStateKeyName = []byte("dagstate")
-
-	// utxoSetVersionKeyName is the name of the db key used to store the
-	// version of the utxo set currently in the database.
-	utxoSetVersionKeyName = []byte("utxosetversion")
-
-	// utxoSetBucketName is the name of the database bucket used to house the
-	// unspent transaction output set.
-	utxoSetBucketName = []byte("utxoset")
-
-	// utxoDiffsBucketName is the name of the database bucket used to house the
-	// diffs and diff children of blocks.
-	utxoDiffsBucketName = []byte("utxodiffs")
-
-	// reachabilityDataBucketName is the name of the database bucket used to house the
-	// reachability tree nodes and future covering sets of blocks.
-	reachabilityDataBucketName = []byte("reachability")
-
-	// subnetworksBucketName is the name of the database bucket used to store the
-	// subnetwork registry.
-	subnetworksBucketName = []byte("subnetworks")
-
-	// localSubnetworkKeyName is the name of the db key used to store the
-	// node's local subnetwork ID.
-	localSubnetworkKeyName = []byte("localsubnetworkidkey")
-
 	// byteOrder is the preferred byte order used for serializing numeric
 	// fields for storage in the database.
 	byteOrder = binary.LittleEndian
@@ -87,167 +46,88 @@ func isNotInDAGErr(err error) bool {
 	return errors.As(err, &notInDAGErr)
 }
 
-// errDeserialize signifies that a problem was encountered when deserializing
-// data.
-type errDeserialize string
-
-// Error implements the error interface.
-func (e errDeserialize) Error() string {
-	return string(e)
-}
-
-// isDeserializeErr returns whether or not the passed error is an errDeserialize
-// error.
-func isDeserializeErr(err error) bool {
-	var deserializeErr errDeserialize
-	return errors.As(err, &deserializeErr)
-}
-
-// dbPutVersion uses an existing database transaction to update the provided
-// key in the metadata bucket to the given version. It is primarily used to
-// track versions on entities such as buckets.
-func dbPutVersion(dbTx database.Tx, key []byte, version uint32) error {
-	var serialized [4]byte
-	byteOrder.PutUint32(serialized[:], version)
-	return dbTx.Metadata().Put(key, serialized[:])
-}
-
-// -----------------------------------------------------------------------------
-// The unspent transaction output (UTXO) set consists of an entry for each
-// unspent output using a format that is optimized to reduce space using domain
-// specific compression algorithms.
-//
-// Each entry is keyed by an outpoint as specified below. It is important to
-// note that the key encoding uses a VLQ, which employs an MSB encoding so
-// iteration of UTXOs when doing byte-wise comparisons will produce them in
-// order.
-//
-// The serialized key format is:
-//   <hash><output index>
-//
-//   Field                Type             Size
-//   hash                 daghash.Hash   daghash.HashSize
-//   output index         VLQ              variable
-//
-// The serialized value format is:
-//
-//   <header code><compressed txout>
-//
-//   Field                Type     Size
-//   header code          VLQ      variable
-//   compressed txout
-//     compressed amount  VLQ      variable
-//     compressed script  []byte   variable
-//
-// The serialized header code format is:
-//   bit 0 - containing transaction is a coinbase
-//   bits 1-x - height of the block that contains the unspent txout
-//
-// Example 1:
-// b7c3332bc138e2c9429818f5fed500bcc1746544218772389054dc8047d7cd3f:0
-//
-//    03320496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52
-//    <><------------------------------------------------------------------>
-//     |                                          |
-//   header code                         compressed txout
-//
-//  - header code: 0x03 (coinbase, height 1)
-//  - compressed txout:
-//    - 0x32: VLQ-encoded compressed amount for 5000000000 (50 KAS)
-//    - 0x04: special script type pay-to-pubkey
-//    - 0x96...52: x-coordinate of the pubkey
-//
-// Example 2:
-// 4a16969aa4764dd7507fc1de7f0baa4850a246de90c45e59a3207f9a26b5036f:2
-//
-//    8cf316800900b8025be1b3efc63b0ad48e7f9f10e87544528d58
-//    <----><------------------------------------------>
-//      |                             |
-//   header code             compressed txout
-//
-//  - header code: 0x8cf316 (not coinbase, height 113931)
-//  - compressed txout:
-//    - 0x8009: VLQ-encoded compressed amount for 15000000 (0.15 KAS)
-//    - 0x00: special script type pay-to-pubkey-hash
-//    - 0xb8...58: pubkey hash
-//
-// Example 3:
-// 1b02d1c8cfef60a189017b9a420c682cf4a0028175f2f563209e4ff61c8c3620:22
-//
-//    a8a2588ba5b9e763011dd46a006572d820e448e12d2bbb38640bc718e6
-//    <----><-------------------------------------------------->
-//      |                             |
-//   header code             compressed txout
-//
-//  - header code: 0xa8a258 (not coinbase, height 338156)
-//  - compressed txout:
-//    - 0x8ba5b9e763: VLQ-encoded compressed amount for 366875659 (3.66875659 KAS)
-//    - 0x01: special script type pay-to-script-hash
-//    - 0x1d...e6: script hash
-// -----------------------------------------------------------------------------
-
-// maxUint32VLQSerializeSize is the maximum number of bytes a max uint32 takes
-// to serialize as a VLQ.
-var maxUint32VLQSerializeSize = serializeSizeVLQ(1<<32 - 1)
-
-// outpointKeyPool defines a concurrent safe free list of byte slices used to
+// outpointKeyPool defines a concurrent safe free list of byte buffers used to
 // provide temporary buffers for outpoint database keys.
 var outpointKeyPool = sync.Pool{
 	New: func() interface{} {
-		b := make([]byte, daghash.HashSize+maxUint32VLQSerializeSize)
-		return &b // Pointer to slice to avoid boxing alloc.
+		return &bytes.Buffer{} // Pointer to a buffer to avoid boxing alloc.
 	},
 }
 
-// outpointKey returns a key suitable for use as a database key in the UTXO set
-// while making use of a free list. A new buffer is allocated if there are not
-// already any available on the free list. The returned byte slice should be
-// returned to the free list by using the recycleOutpointKey function when the
-// caller is done with it _unless_ the slice will need to live for longer than
-// the caller can calculate such as when used to write to the database.
-func outpointKey(outpoint wire.Outpoint) *[]byte {
-	// A VLQ employs an MSB encoding, so they are useful not only to reduce
-	// the amount of storage space, but also so iteration of UTXOs when
-	// doing byte-wise comparisons will produce them in order.
-	key := outpointKeyPool.Get().(*[]byte)
-	idx := uint64(outpoint.Index)
-	*key = (*key)[:daghash.HashSize+serializeSizeVLQ(idx)]
-	copy(*key, outpoint.TxID[:])
-	putVLQ((*key)[daghash.HashSize:], idx)
-	return key
+// outpointIndexByteOrder is the byte order for serializing the outpoint index.
+// It uses big endian to ensure that when outpoint is used as database key, the
+// keys will be iterated in an ascending order by the outpoint index.
+var outpointIndexByteOrder = binary.BigEndian
+
+func serializeOutpoint(w io.Writer, outpoint *wire.Outpoint) error {
+	_, err := w.Write(outpoint.TxID[:])
+	if err != nil {
+		return err
+	}
+
+	return binaryserializer.PutUint32(w, outpointIndexByteOrder, outpoint.Index)
 }
 
-// recycleOutpointKey puts the provided byte slice, which should have been
-// obtained via the outpointKey function, back on the free list.
-func recycleOutpointKey(key *[]byte) {
-	outpointKeyPool.Put(key)
+var outpointSerializeSize = daghash.TxIDSize + 4
+
+// deserializeOutpoint decodes an outpoint from the passed serialized byte
+// slice into a new wire.Outpoint using a format that is suitable for long-
+// term storage. This format is described in detail above.
+func deserializeOutpoint(r io.Reader) (*wire.Outpoint, error) {
+	outpoint := &wire.Outpoint{}
+	_, err := r.Read(outpoint.TxID[:])
+	if err != nil {
+		return nil, err
+	}
+
+	outpoint.Index, err = binaryserializer.Uint32(r, outpointIndexByteOrder)
+	if err != nil {
+		return nil, err
+	}
+
+	return outpoint, nil
 }
 
-// dbPutUTXODiff uses an existing database transaction to update the UTXO set
-// in the database based on the provided UTXO view contents and state. In
-// particular, only the entries that have been marked as modified are written
-// to the database.
-func dbPutUTXODiff(dbTx database.Tx, diff *UTXODiff) error {
-	utxoBucket := dbTx.Metadata().Bucket(utxoSetBucketName)
-	for outpoint := range diff.toRemove {
-		key := outpointKey(outpoint)
-		err := utxoBucket.Delete(*key)
-		recycleOutpointKey(key)
+// updateUTXOSet updates the UTXO set in the database based on the provided
+// UTXO diff.
+func updateUTXOSet(dbContext dbaccess.Context, virtualUTXODiff *UTXODiff) error {
+	for outpoint := range virtualUTXODiff.toRemove {
+		w := outpointKeyPool.Get().(*bytes.Buffer)
+		w.Reset()
+		err := serializeOutpoint(w, &outpoint)
 		if err != nil {
 			return err
 		}
+
+		key := w.Bytes()
+		err = dbaccess.RemoveFromUTXOSet(dbContext, key)
+		if err != nil {
+			return err
+		}
+		outpointKeyPool.Put(w)
 	}
 
-	for outpoint, entry := range diff.toAdd {
+	// We are preallocating for P2PKH entries because they are the most common ones.
+	// If we have entries with a compressed script bigger than P2PKH's, the buffer will grow.
+	bytesToPreallocate := (p2pkhUTXOEntrySerializeSize + outpointSerializeSize) * len(virtualUTXODiff.toAdd)
+	buff := bytes.NewBuffer(make([]byte, bytesToPreallocate))
+	for outpoint, entry := range virtualUTXODiff.toAdd {
 		// Serialize and store the UTXO entry.
-		serialized := serializeUTXOEntry(entry)
+		sBuff := buffers.NewSubBuffer(buff)
+		err := serializeUTXOEntry(sBuff, entry)
+		if err != nil {
+			return err
+		}
+		serializedEntry := sBuff.Bytes()
 
-		key := outpointKey(outpoint)
-		err := utxoBucket.Put(*key, serialized)
-		// NOTE: The key is intentionally not recycled here since the
-		// database interface contract prohibits modifications. It will
-		// be garbage collected normally when the database is done with
-		// it.
+		sBuff = buffers.NewSubBuffer(buff)
+		err = serializeOutpoint(sBuff, &outpoint)
+		if err != nil {
+			return err
+		}
+
+		key := sBuff.Bytes()
+		err = dbaccess.AddToUTXOSet(dbContext, key, serializedEntry)
 		if err != nil {
 			return err
 		}
@@ -259,6 +139,7 @@ func dbPutUTXODiff(dbTx database.Tx, diff *UTXODiff) error {
 type dagState struct {
 	TipHashes         []*daghash.Hash
 	LastFinalityPoint *daghash.Hash
+	LocalSubnetworkID *subnetworkid.SubnetworkID
 }
 
 // serializeDAGState returns the serialization of the DAG state.
@@ -274,366 +155,220 @@ func deserializeDAGState(serializedData []byte) (*dagState, error) {
 	var state *dagState
 	err := json.Unmarshal(serializedData, &state)
 	if err != nil {
-		return nil, database.Error{
-			ErrorCode:   database.ErrCorruption,
-			Description: "corrupt DAG state",
-		}
+		return nil, err
 	}
 
 	return state, nil
 }
 
-// dbPutDAGState uses an existing database transaction to store the latest
+// saveDAGState uses an existing database context to store the latest
 // tip hashes of the DAG.
-func dbPutDAGState(dbTx database.Tx, state *dagState) error {
-	serializedData, err := serializeDAGState(state)
-
+func saveDAGState(dbContext dbaccess.Context, state *dagState) error {
+	serializedDAGState, err := serializeDAGState(state)
 	if err != nil {
 		return err
 	}
 
-	return dbTx.Metadata().Put(dagStateKeyName, serializedData)
+	return dbaccess.StoreDAGState(dbContext, serializedDAGState)
 }
 
-// createDAGState initializes both the database and the DAG state to the
-// genesis block. This includes creating the necessary buckets, so it
-// must only be called on an uninitialized database.
-func (dag *BlockDAG) createDAGState() error {
-	// Create the initial the database DAG state including creating the
-	// necessary index buckets and inserting the genesis block.
-	err := dag.db.Update(func(dbTx database.Tx) error {
-		meta := dbTx.Metadata()
-
-		// Create the bucket that houses the block index data.
-		_, err := meta.CreateBucket(blockIndexBucketName)
-		if err != nil {
-			return err
-		}
-
-		// Create the buckets that house the utxo set, the utxo diffs, and their
-		// version.
-		_, err = meta.CreateBucket(utxoSetBucketName)
-		if err != nil {
-			return err
-		}
-
-		_, err = meta.CreateBucket(utxoDiffsBucketName)
-		if err != nil {
-			return err
-		}
-
-		_, err = meta.CreateBucket(reachabilityDataBucketName)
-		if err != nil {
-			return err
-		}
-
-		err = dbPutVersion(dbTx, utxoSetVersionKeyName,
-			latestUTXOSetBucketVersion)
-		if err != nil {
-			return err
-		}
-
-		// Create the bucket that houses the registered subnetworks.
-		_, err = meta.CreateBucket(subnetworksBucketName)
-		if err != nil {
-			return err
-		}
-
-		if err := dbPutLocalSubnetworkID(dbTx, dag.subnetworkID); err != nil {
-			return err
-		}
-
-		if _, err := meta.CreateBucketIfNotExists(idByHashIndexBucketName); err != nil {
-			return err
-		}
-		if _, err := meta.CreateBucketIfNotExists(hashByIDIndexBucketName); err != nil {
-			return err
-		}
-		return nil
+// createDAGState initializes the DAG state to the
+// genesis block and the node's local subnetwork id.
+func (dag *BlockDAG) createDAGState(localSubnetworkID *subnetworkid.SubnetworkID) error {
+	return saveDAGState(dbaccess.NoTx(), &dagState{
+		TipHashes:         []*daghash.Hash{dag.dagParams.GenesisHash},
+		LastFinalityPoint: dag.dagParams.GenesisHash,
+		LocalSubnetworkID: localSubnetworkID,
 	})
-
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
-func (dag *BlockDAG) removeDAGState() error {
-	err := dag.db.Update(func(dbTx database.Tx) error {
-		meta := dbTx.Metadata()
-
-		err := meta.DeleteBucket(blockIndexBucketName)
-		if err != nil {
-			return err
-		}
-
-		err = meta.DeleteBucket(utxoSetBucketName)
-		if err != nil {
-			return err
-		}
-
-		err = meta.DeleteBucket(utxoDiffsBucketName)
-		if err != nil {
-			return err
-		}
-
-		err = meta.DeleteBucket(reachabilityDataBucketName)
-		if err != nil {
-			return err
-		}
-
-		err = dbTx.Metadata().Delete(utxoSetVersionKeyName)
-		if err != nil {
-			return err
-		}
-
-		err = meta.DeleteBucket(subnetworksBucketName)
-		if err != nil {
-			return err
-		}
-
-		err = dbTx.Metadata().Delete(localSubnetworkKeyName)
-		if err != nil {
-			return err
-		}
-
-		return nil
-	})
-
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
-func dbPutLocalSubnetworkID(dbTx database.Tx, subnetworkID *subnetworkid.SubnetworkID) error {
-	if subnetworkID == nil {
-		return dbTx.Metadata().Put(localSubnetworkKeyName, []byte{})
-	}
-	return dbTx.Metadata().Put(localSubnetworkKeyName, subnetworkID[:])
 }
 
 // initDAGState attempts to load and initialize the DAG state from the
 // database. When the db does not yet contain any DAG state, both it and the
 // DAG state are initialized to the genesis block.
 func (dag *BlockDAG) initDAGState() error {
-	// Determine the state of the DAG database. We may need to initialize
-	// everything from scratch or upgrade certain buckets.
-	var initialized bool
-	err := dag.db.View(func(dbTx database.Tx) error {
-		initialized = dbTx.Metadata().Get(dagStateKeyName) != nil
-		if initialized {
-			var localSubnetworkID *subnetworkid.SubnetworkID
-			localSubnetworkIDBytes := dbTx.Metadata().Get(localSubnetworkKeyName)
-			if len(localSubnetworkIDBytes) != 0 {
-				localSubnetworkID = &subnetworkid.SubnetworkID{}
-				localSubnetworkID.SetBytes(localSubnetworkIDBytes)
-			}
-			if !localSubnetworkID.IsEqual(dag.subnetworkID) {
-				return errors.Errorf("Cannot start kaspad with subnetwork ID %s because"+
-					" its database is already built with subnetwork ID %s. If you"+
-					" want to switch to a new database, please reset the"+
-					" database by starting kaspad with --reset-db flag", dag.subnetworkID, localSubnetworkID)
-			}
-		}
-		return nil
-	})
+	// Fetch the stored DAG state from the database. If it doesn't exist,
+	// it means that kaspad is running for the first time.
+	serializedDAGState, err := dbaccess.FetchDAGState(dbaccess.NoTx())
+	if dbaccess.IsNotFoundError(err) {
+		// Initialize the database and the DAG state to the genesis block.
+		return dag.createDAGState(dag.subnetworkID)
+	}
 	if err != nil {
 		return err
 	}
 
-	if !initialized {
-		// At this point the database has not already been initialized, so
-		// initialize both it and the DAG state to the genesis block.
-		return dag.createDAGState()
+	dagState, err := deserializeDAGState(serializedDAGState)
+	if err != nil {
+		return err
+	}
+	if !dagState.LocalSubnetworkID.IsEqual(dag.subnetworkID) {
+		return errors.Errorf("Cannot start kaspad with subnetwork ID %s because"+
+			" its database is already built with subnetwork ID %s. If you"+
+			" want to switch to a new database, please reset the"+
+			" database by starting kaspad with --reset-db flag", dag.subnetworkID, dagState.LocalSubnetworkID)
 	}
 
-	// Attempt to load the DAG state from the database.
-	return dag.db.View(func(dbTx database.Tx) error {
-		// Fetch the stored DAG tipHashes from the database metadata.
-		// When it doesn't exist, it means the database hasn't been
-		// initialized for use with the DAG yet, so break out now to allow
-		// that to happen under a writable database transaction.
-		serializedData := dbTx.Metadata().Get(dagStateKeyName)
-		log.Tracef("Serialized DAG tip hashes: %x", serializedData)
-		state, err := deserializeDAGState(serializedData)
+	log.Debugf("Loading block index...")
+	var unprocessedBlockNodes []*blockNode
+	blockIndexCursor, err := dbaccess.BlockIndexCursor(dbaccess.NoTx())
+	if err != nil {
+		return err
+	}
+	defer blockIndexCursor.Close()
+	for blockIndexCursor.Next() {
+		serializedDBNode, err := blockIndexCursor.Value()
+		if err != nil {
+			return err
+		}
+		node, err := dag.deserializeBlockNode(serializedDBNode)
 		if err != nil {
 			return err
 		}
 
-		// Load all of the headers from the data for the known DAG
-		// and construct the block index accordingly. Since the
-		// number of nodes are already known, perform a single alloc
-		// for them versus a whole bunch of little ones to reduce
-		// pressure on the GC.
-		log.Infof("Loading block index...")
+		// Check to see if this node had been stored in the the block DB
+		// but not yet accepted. If so, add it to a slice to be processed later.
+		if node.status == statusDataStored {
+			unprocessedBlockNodes = append(unprocessedBlockNodes, node)
+			continue
+		}
 
-		blockIndexBucket := dbTx.Metadata().Bucket(blockIndexBucketName)
-
-		var unprocessedBlockNodes []*blockNode
-		cursor := blockIndexBucket.Cursor()
-		for ok := cursor.First(); ok; ok = cursor.Next() {
-			node, err := dag.deserializeBlockNode(cursor.Value())
-			if err != nil {
-				return err
-			}
-
-			// Check to see if this node had been stored in the the block DB
-			// but not yet accepted. If so, add it to a slice to be processed later.
-			if node.status == statusDataStored {
-				unprocessedBlockNodes = append(unprocessedBlockNodes, node)
-				continue
-			}
-
-			// If the node is known to be invalid add it as-is to the block
-			// index and continue.
-			if node.status.KnownInvalid() {
-				dag.index.addNode(node)
-				continue
-			}
-
-			if dag.blockCount == 0 {
-				if !node.hash.IsEqual(dag.dagParams.GenesisHash) {
-					return AssertError(fmt.Sprintf("initDAGState: Expected "+
-						"first entry in block index to be genesis block, "+
-						"found %s", node.hash))
-				}
-			} else {
-				if len(node.parents) == 0 {
-					return AssertError(fmt.Sprintf("initDAGState: Could "+
-						"not find any parent for block %s", node.hash))
-				}
-			}
-
-			// Add the node to its parents children, connect it,
-			// and add it to the block index.
-			node.updateParentsChildren()
+		// If the node is known to be invalid add it as-is to the block
+		// index and continue.
+		if node.status.KnownInvalid() {
 			dag.index.addNode(node)
-
-			dag.blockCount++
+			continue
 		}
 
-		// Load all of the known UTXO entries and construct the full
-		// UTXO set accordingly. Since the number of entries is already
-		// known, perform a single alloc for them versus a whole bunch
-		// of little ones to reduce pressure on the GC.
-		log.Infof("Loading UTXO set...")
-
-		utxoEntryBucket := dbTx.Metadata().Bucket(utxoSetBucketName)
-
-		// Determine how many UTXO entries will be loaded into the index so we can
-		// allocate the right amount.
-		var utxoEntryCount int32
-		cursor = utxoEntryBucket.Cursor()
-		for ok := cursor.First(); ok; ok = cursor.Next() {
-			utxoEntryCount++
-		}
-
-		fullUTXOCollection := make(utxoCollection, utxoEntryCount)
-		for ok := cursor.First(); ok; ok = cursor.Next() {
-			// Deserialize the outpoint
-			outpoint, err := deserializeOutpoint(cursor.Key())
-			if err != nil {
-				// Ensure any deserialization errors are returned as database
-				// corruption errors.
-				if isDeserializeErr(err) {
-					return database.Error{
-						ErrorCode:   database.ErrCorruption,
-						Description: fmt.Sprintf("corrupt outpoint: %s", err),
-					}
-				}
-
-				return err
+		if dag.blockCount == 0 {
+			if !node.hash.IsEqual(dag.dagParams.GenesisHash) {
+				return AssertError(fmt.Sprintf("initDAGState: Expected "+
+					"first entry in block index to be genesis block, "+
+					"found %s", node.hash))
 			}
-
-			// Deserialize the utxo entry
-			entry, err := deserializeUTXOEntry(cursor.Value())
-			if err != nil {
-				// Ensure any deserialization errors are returned as database
-				// corruption errors.
-				if isDeserializeErr(err) {
-					return database.Error{
-						ErrorCode:   database.ErrCorruption,
-						Description: fmt.Sprintf("corrupt utxo entry: %s", err),
-					}
-				}
-
-				return err
+		} else {
+			if len(node.parents) == 0 {
+				return AssertError(fmt.Sprintf("initDAGState: block %s "+
+					"has no parents but it's not the genesis block", node.hash))
 			}
-
-			fullUTXOCollection[*outpoint] = entry
 		}
 
-		// Initialize the reachability store
-		err = dag.reachabilityStore.init(dbTx)
+		// Add the node to its parents children, connect it,
+		// and add it to the block index.
+		node.updateParentsChildren()
+		dag.index.addNode(node)
+
+		dag.blockCount++
+	}
+
+	log.Debugf("Loading UTXO set...")
+	fullUTXOCollection := make(utxoCollection)
+	cursor, err := dbaccess.UTXOSetCursor(dbaccess.NoTx())
+	if err != nil {
+		return err
+	}
+	defer cursor.Close()
+
+	for cursor.Next() {
+		// Deserialize the outpoint
+		key, err := cursor.Key()
+		if err != nil {
+			return err
+		}
+		outpoint, err := deserializeOutpoint(bytes.NewReader(key))
 		if err != nil {
 			return err
 		}
 
-		// Apply the loaded utxoCollection to the virtual block.
-		dag.virtual.utxoSet, err = newFullUTXOSetFromUTXOCollection(fullUTXOCollection)
+		// Deserialize the utxo entry
+		value, err := cursor.Value()
 		if err != nil {
-			return AssertError(fmt.Sprintf("Error loading UTXOSet: %s", err))
+			return err
+		}
+		entry, err := deserializeUTXOEntry(bytes.NewReader(value))
+		if err != nil {
+			return err
 		}
 
-		// Apply the stored tips to the virtual block.
-		tips := newBlockSet()
-		for _, tipHash := range state.TipHashes {
-			tip := dag.index.LookupNode(tipHash)
-			if tip == nil {
-				return AssertError(fmt.Sprintf("initDAGState: cannot find "+
-					"DAG tip %s in block index", state.TipHashes))
-			}
-			tips.add(tip)
+		fullUTXOCollection[*outpoint] = entry
+	}
+
+	log.Debugf("Loading reachability data...")
+	err = dag.reachabilityStore.init(dbaccess.NoTx())
+	if err != nil {
+		return err
+	}
+
+	log.Debugf("Loading multiset data...")
+	err = dag.multisetStore.init(dbaccess.NoTx())
+	if err != nil {
+		return err
+	}
+
+	log.Debugf("Applying the loaded utxoCollection to the virtual block...")
+	dag.virtual.utxoSet, err = newFullUTXOSetFromUTXOCollection(fullUTXOCollection)
+	if err != nil {
+		return AssertError(fmt.Sprintf("Error loading UTXOSet: %s", err))
+	}
+
+	log.Debugf("Applying the stored tips to the virtual block...")
+	tips := newBlockSet()
+	for _, tipHash := range dagState.TipHashes {
+		tip := dag.index.LookupNode(tipHash)
+		if tip == nil {
+			return AssertError(fmt.Sprintf("initDAGState: cannot find "+
+				"DAG tip %s in block index", dagState.TipHashes))
 		}
-		dag.virtual.SetTips(tips)
+		tips.add(tip)
+	}
+	dag.virtual.SetTips(tips)
 
-		// Set the last finality point
-		dag.lastFinalityPoint = dag.index.LookupNode(state.LastFinalityPoint)
-		dag.finalizeNodesBelowFinalityPoint(false)
+	log.Debugf("Setting the last finality point...")
+	dag.lastFinalityPoint = dag.index.LookupNode(dagState.LastFinalityPoint)
+	dag.finalizeNodesBelowFinalityPoint(false)
 
-		// Go over any unprocessed blockNodes and process them now.
-		for _, node := range unprocessedBlockNodes {
-			// Check to see if the block exists in the block DB. If it
-			// doesn't, the database has certainly been corrupted.
-			blockExists, err := dbTx.HasBlock(node.hash)
-			if err != nil {
-				return AssertError(fmt.Sprintf("initDAGState: HasBlock "+
-					"for block %s failed: %s", node.hash, err))
-			}
-			if !blockExists {
-				return AssertError(fmt.Sprintf("initDAGState: block %s "+
-					"exists in block index but not in block db", node.hash))
-			}
-
-			// Attempt to accept the block.
-			block, err := dbFetchBlockByNode(dbTx, node)
-			if err != nil {
-				return err
-			}
-			isOrphan, isDelayed, err := dag.ProcessBlock(block, BFWasStored)
-			if err != nil {
-				log.Warnf("Block %s, which was not previously processed, "+
-					"failed to be accepted to the DAG: %s", node.hash, err)
-				continue
-			}
-
-			// If the block is an orphan or is delayed then it couldn't have
-			// possibly been written to the block index in the first place.
-			if isOrphan {
-				return AssertError(fmt.Sprintf("Block %s, which was not "+
-					"previously processed, turned out to be an orphan, which is "+
-					"impossible.", node.hash))
-			}
-			if isDelayed {
-				return AssertError(fmt.Sprintf("Block %s, which was not "+
-					"previously processed, turned out to be delayed, which is "+
-					"impossible.", node.hash))
-			}
+	log.Debugf("Processing unprocessed blockNodes...")
+	for _, node := range unprocessedBlockNodes {
+		// Check to see if the block exists in the block DB. If it
+		// doesn't, the database has certainly been corrupted.
+		blockExists, err := dbaccess.HasBlock(dbaccess.NoTx(), node.hash)
+		if err != nil {
+			return AssertError(fmt.Sprintf("initDAGState: HasBlock "+
+				"for block %s failed: %s", node.hash, err))
+		}
+		if !blockExists {
+			return AssertError(fmt.Sprintf("initDAGState: block %s "+
+				"exists in block index but not in block db", node.hash))
 		}
 
-		return nil
-	})
+		// Attempt to accept the block.
+		block, err := fetchBlockByHash(dbaccess.NoTx(), node.hash)
+		if err != nil {
+			return err
+		}
+		isOrphan, isDelayed, err := dag.ProcessBlock(block, BFWasStored)
+		if err != nil {
+			log.Warnf("Block %s, which was not previously processed, "+
+				"failed to be accepted to the DAG: %s", node.hash, err)
+			continue
+		}
+
+		// If the block is an orphan or is delayed then it couldn't have
+		// possibly been written to the block index in the first place.
+		if isOrphan {
+			return AssertError(fmt.Sprintf("Block %s, which was not "+
+				"previously processed, turned out to be an orphan, which is "+
+				"impossible.", node.hash))
+		}
+		if isDelayed {
+			return AssertError(fmt.Sprintf("Block %s, which was not "+
+				"previously processed, turned out to be delayed, which is "+
+				"impossible.", node.hash))
+		}
+	}
+
+	log.Infof("DAG state initialized.")
+
+	return nil
 }
 
 // deserializeBlockNode parses a value in the block index bucket and returns a block node.
@@ -729,26 +464,26 @@ func (dag *BlockDAG) deserializeBlockNode(blockRow []byte) (*blockNode, error) {
 	return node, nil
 }
 
-// dbFetchBlockByNode uses an existing database transaction to retrieve the
-// raw block for the provided node, deserialize it, and return a util.Block
-// of it.
-func dbFetchBlockByNode(dbTx database.Tx, node *blockNode) (*util.Block, error) {
-	// Load the raw block bytes from the database.
-	blockBytes, err := dbTx.FetchBlock(node.hash)
+// fetchBlockByHash retrieves the raw block for the provided hash,
+// deserializes it, and returns a util.Block of it.
+func fetchBlockByHash(dbContext dbaccess.Context, hash *daghash.Hash) (*util.Block, error) {
+	blockBytes, err := dbaccess.FetchBlock(dbContext, hash)
 	if err != nil {
 		return nil, err
 	}
+	return util.NewBlockFromBytes(blockBytes)
+}
 
-	// Create the encapsulated block.
-	block, err := util.NewBlockFromBytes(blockBytes)
+func storeBlock(dbContext *dbaccess.TxContext, block *util.Block) error {
+	blockBytes, err := block.Bytes()
 	if err != nil {
-		return nil, err
+		return err
 	}
-	return block, nil
+	return dbaccess.StoreBlock(dbContext, block.Hash(), blockBytes)
 }
 
 func serializeBlockNode(node *blockNode) ([]byte, error) {
-	w := bytes.NewBuffer(make([]byte, 0, blockHdrSize+1))
+	w := bytes.NewBuffer(make([]byte, 0, wire.MaxBlockHeaderPayload+1))
 	header := node.Header()
 	err := header.Serialize(w)
 	if err != nil {
@@ -805,37 +540,11 @@ func serializeBlockNode(node *blockNode) ([]byte, error) {
 	return w.Bytes(), nil
 }
 
-// dbStoreBlockNode stores the block node data into the block
-// index bucket. This overwrites the current entry if there exists one.
-func dbStoreBlockNode(dbTx database.Tx, node *blockNode) error {
-	serializedNode, err := serializeBlockNode(node)
-	if err != nil {
-		return err
-	}
-	// Write block header data to block index bucket.
-	blockIndexBucket := dbTx.Metadata().Bucket(blockIndexBucketName)
-	key := BlockIndexKey(node.hash, node.blueScore)
-	return blockIndexBucket.Put(key, serializedNode)
-}
-
-// dbStoreBlock stores the provided block in the database if it is not already
-// there. The full block data is written to ffldb.
-func dbStoreBlock(dbTx database.Tx, block *util.Block) error {
-	hasBlock, err := dbTx.HasBlock(block.Hash())
-	if err != nil {
-		return err
-	}
-	if hasBlock {
-		return nil
-	}
-	return dbTx.StoreBlock(block)
-}
-
-// BlockIndexKey generates the binary key for an entry in the block index
+// blockIndexKey generates the binary key for an entry in the block index
 // bucket. The key is composed of the block blue score encoded as a big-endian
 // 64-bit unsigned int followed by the 32 byte block hash.
 // The blue score component is important for iteration order.
-func BlockIndexKey(blockHash *daghash.Hash, blueScore uint64) []byte {
+func blockIndexKey(blockHash *daghash.Hash, blueScore uint64) []byte {
 	indexKey := make([]byte, daghash.HashSize+8)
 	binary.BigEndian.PutUint64(indexKey[0:8], blueScore)
 	copy(indexKey[8:daghash.HashSize+8], blockHash[:])
@@ -857,13 +566,10 @@ func (dag *BlockDAG) BlockByHash(hash *daghash.Hash) (*util.Block, error) {
 		return nil, errNotInDAG(str)
 	}
 
-	// Load the block from the database and return it.
-	var block *util.Block
-	err := dag.db.View(func(dbTx database.Tx) error {
-		var err error
-		block, err = dbFetchBlockByNode(dbTx, node)
-		return err
-	})
+	block, err := fetchBlockByHash(dbaccess.NoTx(), node.hash)
+	if err != nil {
+		return nil, err
+	}
 	return block, err
 }
 
@@ -888,27 +594,27 @@ func (dag *BlockDAG) BlockHashesFrom(lowHash *daghash.Hash, limit int) ([]*dagha
 		return nil, err
 	}
 
-	err = dag.index.db.View(func(dbTx database.Tx) error {
-		blockIndexBucket := dbTx.Metadata().Bucket(blockIndexBucketName)
-		lowKey := BlockIndexKey(lowHash, blueScore)
-
-		cursor := blockIndexBucket.Cursor()
-		cursor.Seek(lowKey)
-		for ok := cursor.Next(); ok; ok = cursor.Next() {
-			key := cursor.Key()
-			blockHash, err := blockHashFromBlockIndexKey(key)
-			if err != nil {
-				return err
-			}
-			blockHashes = append(blockHashes, blockHash)
-			if len(blockHashes) == limit {
-				break
-			}
-		}
-		return nil
-	})
+	key := blockIndexKey(lowHash, blueScore)
+	cursor, err := dbaccess.BlockIndexCursorFrom(dbaccess.NoTx(), key)
+	if dbaccess.IsNotFoundError(err) {
+		return nil, errors.Wrapf(err, "block %s not in block index", lowHash)
+	}
 	if err != nil {
 		return nil, err
 	}
+	defer cursor.Close()
+
+	for cursor.Next() && len(blockHashes) < limit {
+		key, err := cursor.Key()
+		if err != nil {
+			return nil, err
+		}
+		blockHash, err := blockHashFromBlockIndexKey(key)
+		if err != nil {
+			return nil, err
+		}
+		blockHashes = append(blockHashes, blockHash)
+	}
+
 	return blockHashes, nil
 }

blockdag/dagio_test.go

@@ -6,11 +6,11 @@ package blockdag
 
 import (
 	"bytes"
+	"encoding/hex"
 	"github.com/pkg/errors"
 	"reflect"
 	"testing"
 
-	"github.com/kaspanet/kaspad/database"
 	"github.com/kaspanet/kaspad/util/daghash"
 )
 
@@ -36,9 +36,21 @@ func TestErrNotInDAG(t *testing.T) {
 	}
 }
 
-// TestUtxoSerialization ensures serializing and deserializing unspent
+// hexToBytes converts the passed hex string into bytes and will panic if there
+// is an error. This is only provided for the hard-coded constants so errors in
+// the source code can be detected. It will only (and must only) be called with
+// hard-coded values.
+func hexToBytes(s string) []byte {
+	b, err := hex.DecodeString(s)
+	if err != nil {
+		panic("invalid hex in source file: " + s)
+	}
+	return b
+}
+
+// TestUTXOSerialization ensures serializing and deserializing unspent
 // trasaction output entries works as expected.
-func TestUtxoSerialization(t *testing.T) {
+func TestUTXOSerialization(t *testing.T) {
 	t.Parallel()
 
 	tests := []struct {
@@ -54,7 +66,7 @@ func TestUtxoSerialization(t *testing.T) {
 				blockBlueScore: 1,
 				packedFlags:    tfCoinbase,
 			},
-			serialized: hexToBytes("03320496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52"),
+			serialized: hexToBytes("030000000000000000f2052a0100000043410496b538e853519c726a2c91e61ec11600ae1390813a627c66fb8be7947be63c52da7589379515d4e0a604f8141781e62294721166bf621e73a82cbf2342c858eeac"),
 		},
 		{
 			name: "blue score 100001, not coinbase",
@@ -64,13 +76,21 @@ func TestUtxoSerialization(t *testing.T) {
 				blockBlueScore: 100001,
 				packedFlags:    0,
 			},
-			serialized: hexToBytes("8b99420700ee8bd501094a7d5ca318da2506de35e1cb025ddc"),
+			serialized: hexToBytes("420d03000000000040420f00000000001976a914ee8bd501094a7d5ca318da2506de35e1cb025ddc88ac"),
 		},
 	}
 
 	for i, test := range tests {
 		// Ensure the utxo entry serializes to the expected value.
-		gotBytes := serializeUTXOEntry(test.entry)
+		w := &bytes.Buffer{}
+		err := serializeUTXOEntry(w, test.entry)
+		if err != nil {
+			t.Errorf("serializeUTXOEntry #%d (%s) unexpected "+
+				"error: %v", i, test.name, err)
+			continue
+		}
+
+		gotBytes := w.Bytes()
 		if !bytes.Equal(gotBytes, test.serialized) {
 			t.Errorf("serializeUTXOEntry #%d (%s): mismatched "+
 				"bytes - got %x, want %x", i, test.name,
@@ -78,8 +98,8 @@ func TestUtxoSerialization(t *testing.T) {
 			continue
 		}
 
-		// Deserialize to a utxo entry.
-		utxoEntry, err := deserializeUTXOEntry(test.serialized)
+		// Deserialize to a utxo entry.gotBytes
+		utxoEntry, err := deserializeUTXOEntry(bytes.NewReader(test.serialized))
 		if err != nil {
 			t.Errorf("deserializeUTXOEntry #%d (%s) unexpected "+
 				"error: %v", i, test.name, err)
@@ -124,28 +144,24 @@ func TestUtxoEntryDeserializeErrors(t *testing.T) {
 	tests := []struct {
 		name       string
 		serialized []byte
-		errType    error
 	}{
 		{
 			name:       "no data after header code",
 			serialized: hexToBytes("02"),
-			errType:    errDeserialize(""),
 		},
 		{
 			name:       "incomplete compressed txout",
 			serialized: hexToBytes("0232"),
-			errType:    errDeserialize(""),
 		},
 	}
 
 	for _, test := range tests {
 		// Ensure the expected error type is returned and the returned
 		// entry is nil.
-		entry, err := deserializeUTXOEntry(test.serialized)
-		if reflect.TypeOf(err) != reflect.TypeOf(test.errType) {
-			t.Errorf("deserializeUTXOEntry (%s): expected error "+
-				"type does not match - got %T, want %T",
-				test.name, err, test.errType)
+		entry, err := deserializeUTXOEntry(bytes.NewReader(test.serialized))
+		if err == nil {
+			t.Errorf("deserializeUTXOEntry (%s): didn't return an error",
+				test.name)
 			continue
 		}
 		if entry != nil {
@@ -172,7 +188,7 @@ func TestDAGStateSerialization(t *testing.T) {
 				TipHashes:         []*daghash.Hash{newHashFromStr("000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f")},
 				LastFinalityPoint: newHashFromStr("000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"),
 			},
-			serialized: []byte("{\"TipHashes\":[[111,226,140,10,182,241,179,114,193,166,162,70,174,99,247,79,147,30,131,101,225,90,8,156,104,214,25,0,0,0,0,0]],\"LastFinalityPoint\":[111,226,140,10,182,241,179,114,193,166,162,70,174,99,247,79,147,30,131,101,225,90,8,156,104,214,25,0,0,0,0,0]}"),
+			serialized: []byte("{\"TipHashes\":[[111,226,140,10,182,241,179,114,193,166,162,70,174,99,247,79,147,30,131,101,225,90,8,156,104,214,25,0,0,0,0,0]],\"LastFinalityPoint\":[111,226,140,10,182,241,179,114,193,166,162,70,174,99,247,79,147,30,131,101,225,90,8,156,104,214,25,0,0,0,0,0],\"LocalSubnetworkID\":null}"),
 		},
 		{
 			name: "block 1",
@@ -180,7 +196,7 @@ func TestDAGStateSerialization(t *testing.T) {
 				TipHashes:         []*daghash.Hash{newHashFromStr("00000000839a8e6886ab5951d76f411475428afc90947ee320161bbf18eb6048")},
 				LastFinalityPoint: newHashFromStr("000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"),
 			},
-			serialized: []byte("{\"TipHashes\":[[72,96,235,24,191,27,22,32,227,126,148,144,252,138,66,117,20,65,111,215,81,89,171,134,104,142,154,131,0,0,0,0]],\"LastFinalityPoint\":[111,226,140,10,182,241,179,114,193,166,162,70,174,99,247,79,147,30,131,101,225,90,8,156,104,214,25,0,0,0,0,0]}"),
+			serialized: []byte("{\"TipHashes\":[[72,96,235,24,191,27,22,32,227,126,148,144,252,138,66,117,20,65,111,215,81,89,171,134,104,142,154,131,0,0,0,0]],\"LastFinalityPoint\":[111,226,140,10,182,241,179,114,193,166,162,70,174,99,247,79,147,30,131,101,225,90,8,156,104,214,25,0,0,0,0,0],\"LocalSubnetworkID\":null}"),
 		},
 	}
 
@@ -217,51 +233,6 @@ func TestDAGStateSerialization(t *testing.T) {
 	}
 }
 
-// TestDAGStateDeserializeErrors performs negative tests against
-// deserializing the DAG state to ensure error paths work as expected.
-func TestDAGStateDeserializeErrors(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name       string
-		serialized []byte
-		errType    error
-	}{
-		{
-			name:       "nothing serialized",
-			serialized: hexToBytes(""),
-			errType:    database.Error{ErrorCode: database.ErrCorruption},
-		},
-		{
-			name:       "corrupted data",
-			serialized: []byte("[[111,226,140,10,182,241,179,114,193,166,162,70,174,99,247,7"),
-			errType:    database.Error{ErrorCode: database.ErrCorruption},
-		},
-	}
-
-	for _, test := range tests {
-		// Ensure the expected error type and code is returned.
-		_, err := deserializeDAGState(test.serialized)
-		if reflect.TypeOf(err) != reflect.TypeOf(test.errType) {
-			t.Errorf("deserializeDAGState (%s): expected "+
-				"error type does not match - got %T, want %T",
-				test.name, err, test.errType)
-			continue
-		}
-		var dbErr database.Error
-		if ok := errors.As(err, &dbErr); ok {
-			tderr := test.errType.(database.Error)
-			if dbErr.ErrorCode != tderr.ErrorCode {
-				t.Errorf("deserializeDAGState (%s): "+
-					"wrong error code got: %v, want: %v",
-					test.name, dbErr.ErrorCode,
-					tderr.ErrorCode)
-				continue
-			}
-		}
-	}
-}
-
 // newHashFromStr converts the passed big-endian hex string into a
 // daghash.Hash. It only differs from the one available in daghash in that
 // it panics in case of an error since it will only (and must only) be

blockdag/difficulty_test.go

@@ -82,7 +82,7 @@ func TestDifficulty(t *testing.T) {
 	params := dagconfig.SimnetParams
 	params.K = 1
 	params.DifficultyAdjustmentWindowSize = 264
-	dag, teardownFunc, err := DAGSetup("TestDifficulty", Config{
+	dag, teardownFunc, err := DAGSetup("TestDifficulty", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -94,7 +94,8 @@ func TestDifficulty(t *testing.T) {
 	addNode := func(parents blockSet, blockTime time.Time) *blockNode {
 		bluestParent := parents.bluest()
 		if blockTime == zeroTime {
-			blockTime = time.Unix(bluestParent.timestamp+1, 0)
+			blockTime = time.Unix(bluestParent.timestamp, 0)
+			blockTime = blockTime.Add(params.TargetTimePerBlock)
 		}
 		block, err := PrepareBlockForTest(dag, parents.hashes(), nil)
 		if err != nil {
@@ -119,7 +120,8 @@ func TestDifficulty(t *testing.T) {
 	for i := uint64(0); i < dag.difficultyAdjustmentWindowSize; i++ {
 		tip = addNode(blockSetFromSlice(tip), zeroTime)
 		if tip.bits != dag.genesis.bits {
-			t.Fatalf("As long as the bluest parent's blue score is less then the difficulty adjustment window size, the difficulty should be the same as genesis'")
+			t.Fatalf("As long as the bluest parent's blue score is less then the difficulty adjustment " +
+				"window size, the difficulty should be the same as genesis'")
 		}
 	}
 	for i := uint64(0); i < dag.difficultyAdjustmentWindowSize+100; i++ {
@@ -140,7 +142,8 @@ func TestDifficulty(t *testing.T) {
 	}
 	tip = addNode(blockSetFromSlice(tip), zeroTime)
 	if compareBits(tip.bits, nodeInThePast.bits) >= 0 {
-		t.Fatalf("tip.bits should be smaller than nodeInThePast.bits because nodeInThePast increased the block rate, so the difficulty should increase as well")
+		t.Fatalf("tip.bits should be smaller than nodeInThePast.bits because nodeInThePast increased the " +
+			"block rate, so the difficulty should increase as well")
 	}
 	expectedBits := uint32(0x207f83df)
 	if tip.bits != expectedBits {
@@ -167,7 +170,9 @@ func TestDifficulty(t *testing.T) {
 			sameBitsCount = 0
 		}
 	}
-	slowNode := addNode(blockSetFromSlice(tip), time.Unix(tip.timestamp+2, 0))
+	slowBlockTime := time.Unix(tip.timestamp, 0)
+	slowBlockTime = slowBlockTime.Add(params.TargetTimePerBlock + time.Second)
+	slowNode := addNode(blockSetFromSlice(tip), slowBlockTime)
 	if slowNode.bits != tip.bits {
 		t.Fatalf("The difficulty should only change when slowNode is in the past of a block bluest parent")
 	}
@@ -180,7 +185,8 @@ func TestDifficulty(t *testing.T) {
 	}
 	tip = addNode(blockSetFromSlice(tip), zeroTime)
 	if compareBits(tip.bits, slowNode.bits) <= 0 {
-		t.Fatalf("tip.bits should be smaller than slowNode.bits because slowNode decreased the block rate, so the difficulty should decrease as well")
+		t.Fatalf("tip.bits should be smaller than slowNode.bits because slowNode decreased the block" +
+			" rate, so the difficulty should decrease as well")
 	}
 
 	splitNode := addNode(blockSetFromSlice(tip), zeroTime)
@@ -197,7 +203,8 @@ func TestDifficulty(t *testing.T) {
 	tipWithRedPast := addNode(blockSetFromSlice(redChainTip, blueTip), zeroTime)
 	tipWithoutRedPast := addNode(blockSetFromSlice(blueTip), zeroTime)
 	if tipWithoutRedPast.bits != tipWithRedPast.bits {
-		t.Fatalf("tipWithoutRedPast.bits should be the same as tipWithRedPast.bits because red blocks shouldn't affect the difficulty")
+		t.Fatalf("tipWithoutRedPast.bits should be the same as tipWithRedPast.bits because red blocks" +
+			" shouldn't affect the difficulty")
 	}
 }
 

blockdag/external_dag_test.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"github.com/pkg/errors"
 	"math"
+	"strings"
 	"testing"
 
 	"github.com/kaspanet/kaspad/util/subnetworkid"
@@ -40,7 +41,7 @@ func TestFinality(t *testing.T) {
 	params := dagconfig.SimnetParams
 	params.K = 1
 	params.FinalityInterval = 100
-	dag, teardownFunc, err := blockdag.DAGSetup("TestFinality", blockdag.Config{
+	dag, teardownFunc, err := blockdag.DAGSetup("TestFinality", true, blockdag.Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -185,7 +186,7 @@ func TestSubnetworkRegistry(t *testing.T) {
 	params := dagconfig.SimnetParams
 	params.K = 1
 	params.BlockCoinbaseMaturity = 0
-	dag, teardownFunc, err := blockdag.DAGSetup("TestSubnetworkRegistry", blockdag.Config{
+	dag, teardownFunc, err := blockdag.DAGSetup("TestSubnetworkRegistry", true, blockdag.Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -198,7 +199,7 @@ func TestSubnetworkRegistry(t *testing.T) {
 	if err != nil {
 		t.Fatalf("could not register network: %s", err)
 	}
-	limit, err := dag.SubnetworkStore.GasLimit(subnetworkID)
+	limit, err := blockdag.GasLimit(subnetworkID)
 	if err != nil {
 		t.Fatalf("could not retrieve gas limit: %s", err)
 	}
@@ -211,7 +212,7 @@ func TestChainedTransactions(t *testing.T) {
 	params := dagconfig.SimnetParams
 	params.BlockCoinbaseMaturity = 0
 	// Create a new database and dag instance to run tests against.
-	dag, teardownFunc, err := blockdag.DAGSetup("TestChainedTransactions", blockdag.Config{
+	dag, teardownFunc, err := blockdag.DAGSetup("TestChainedTransactions", true, blockdag.Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -267,11 +268,19 @@ func TestChainedTransactions(t *testing.T) {
 	}
 	chainedTx := wire.NewNativeMsgTx(wire.TxVersion, []*wire.TxIn{chainedTxIn}, []*wire.TxOut{chainedTxOut})
 
-	block2, err := mining.PrepareBlockForTest(dag, &params, []*daghash.Hash{block1.BlockHash()}, []*wire.MsgTx{tx, chainedTx}, true)
+	block2, err := mining.PrepareBlockForTest(dag, &params, []*daghash.Hash{block1.BlockHash()}, []*wire.MsgTx{tx}, false)
 	if err != nil {
 		t.Fatalf("PrepareBlockForTest: %v", err)
 	}
 
+	// Manually add a chained transaction to block2
+	block2.Transactions = append(block2.Transactions, chainedTx)
+	block2UtilTxs := make([]*util.Tx, len(block2.Transactions))
+	for i, tx := range block2.Transactions {
+		block2UtilTxs[i] = util.NewTx(tx)
+	}
+	block2.Header.HashMerkleRoot = blockdag.BuildHashMerkleTreeStore(block2UtilTxs).Root()
+
 	//Checks that dag.ProcessBlock fails because we don't allow a transaction to spend another transaction from the same block
 	isOrphan, isDelayed, err = dag.ProcessBlock(util.NewBlock(block2), blockdag.BFNoPoWCheck)
 	if err == nil {
@@ -331,7 +340,7 @@ func TestOrderInDiffFromAcceptanceData(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
 	params := dagconfig.SimnetParams
 	params.K = math.MaxUint8
-	dag, teardownFunc, err := blockdag.DAGSetup("TestOrderInDiffFromAcceptanceData", blockdag.Config{
+	dag, teardownFunc, err := blockdag.DAGSetup("TestOrderInDiffFromAcceptanceData", true, blockdag.Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -401,7 +410,7 @@ func TestGasLimit(t *testing.T) {
 	params := dagconfig.SimnetParams
 	params.K = 1
 	params.BlockCoinbaseMaturity = 0
-	dag, teardownFunc, err := blockdag.DAGSetup("TestSubnetworkRegistry", blockdag.Config{
+	dag, teardownFunc, err := blockdag.DAGSetup("TestSubnetworkRegistry", true, blockdag.Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -548,7 +557,7 @@ func TestGasLimit(t *testing.T) {
 	isOrphan, isDelayed, err = dag.ProcessBlock(util.NewBlock(nonExistentSubnetworkBlock), blockdag.BFNoPoWCheck)
 	expectedErrStr := fmt.Sprintf("Error getting gas limit for subnetworkID '%s': subnetwork '%s' not found",
 		nonExistentSubnetwork, nonExistentSubnetwork)
-	if err.Error() != expectedErrStr {
+	if strings.Contains(err.Error(), expectedErrStr) {
 		t.Fatalf("ProcessBlock expected error \"%v\" but got \"%v\"", expectedErrStr, err)
 	}
 	if isDelayed {

blockdag/ghostdag_test.go

@@ -3,7 +3,7 @@ package blockdag
 import (
 	"fmt"
 	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"reflect"
@@ -33,7 +33,7 @@ func TestGHOSTDAG(t *testing.T) {
 	}{
 		{
 			k:            3,
-			expectedReds: []string{"F", "G", "H", "I", "O", "P"},
+			expectedReds: []string{"F", "G", "H", "I", "N", "Q"},
 			dagData: []*testBlockData{
 				{
 					parents:                []string{"A"},
@@ -166,7 +166,7 @@ func TestGHOSTDAG(t *testing.T) {
 					id:                     "T",
 					expectedScore:          13,
 					expectedSelectedParent: "S",
-					expectedBlues:          []string{"S", "N", "Q"},
+					expectedBlues:          []string{"S", "O", "P"},
 				},
 			},
 		},
@@ -176,7 +176,7 @@ func TestGHOSTDAG(t *testing.T) {
 		func() {
 			resetExtraNonceForTest()
 			dagParams.K = test.k
-			dag, teardownFunc, err := DAGSetup(fmt.Sprintf("TestGHOSTDAG%d", i), Config{
+			dag, teardownFunc, err := DAGSetup(fmt.Sprintf("TestGHOSTDAG%d", i), true, Config{
 				DAGParams: &dagParams,
 			})
 			if err != nil {
@@ -282,7 +282,7 @@ func checkReds(expectedReds []string, reds map[string]bool) bool {
 
 func TestBlueAnticoneSizeErrors(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("TestBlueAnticoneSizeErrors", Config{
+	dag, teardownFunc, err := DAGSetup("TestBlueAnticoneSizeErrors", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
@@ -323,7 +323,7 @@ func TestBlueAnticoneSizeErrors(t *testing.T) {
 
 func TestGHOSTDAGErrors(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("TestGHOSTDAGErrors", Config{
+	dag, teardownFunc, err := DAGSetup("TestGHOSTDAGErrors", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
@@ -340,19 +340,21 @@ func TestGHOSTDAGErrors(t *testing.T) {
 
 	// Clear the reachability store
 	dag.reachabilityStore.loaded = map[daghash.Hash]*reachabilityData{}
-	err = dag.db.Update(func(dbTx database.Tx) error {
-		bucket := dbTx.Metadata().Bucket(reachabilityDataBucketName)
-		cursor := bucket.Cursor()
-		for ok := cursor.First(); ok; ok = cursor.Next() {
-			err := bucket.Delete(cursor.Key())
-			if err != nil {
-				return err
-			}
-		}
-		return nil
-	})
+
+	dbTx, err := dbaccess.NewTx()
 	if err != nil {
-		t.Fatalf("TestGHOSTDAGErrors: db.Update failed: %s", err)
+		t.Fatalf("NewTx: %s", err)
+	}
+	defer dbTx.RollbackUnlessClosed()
+
+	err = dbaccess.ClearReachabilityData(dbTx)
+	if err != nil {
+		t.Fatalf("ClearReachabilityData: %s", err)
+	}
+
+	err = dbTx.Commit()
+	if err != nil {
+		t.Fatalf("Commit: %s", err)
 	}
 
 	// Try to rerun GHOSTDAG on the last block. GHOSTDAG uses

blockdag/indexers/acceptanceindex.go

@@ -4,29 +4,16 @@ import (
 	"bytes"
 	"encoding/gob"
 	"github.com/kaspanet/kaspad/blockdag"
-	"github.com/kaspanet/kaspad/database"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
-	"github.com/pkg/errors"
-)
-
-const (
-	// acceptanceIndexName is the human-readable name for the index.
-	acceptanceIndexName = "acceptance index"
-)
-
-var (
-	// acceptanceIndexKey is the key of the acceptance index and the db bucket used
-	// to house it.
-	acceptanceIndexKey = []byte("acceptanceidx")
 )
 
 // AcceptanceIndex implements a txAcceptanceData by block hash index. That is to say,
 // it stores a mapping between a block's hash and the set of transactions that the
 // block accepts among its blue blocks.
 type AcceptanceIndex struct {
-	db  database.DB
 	dag *blockdag.BlockDAG
 }
 
@@ -43,122 +30,82 @@ func NewAcceptanceIndex() *AcceptanceIndex {
 	return &AcceptanceIndex{}
 }
 
-// DropAcceptanceIndex drops the acceptance index from the provided database if it
-// exists.
-func DropAcceptanceIndex(db database.DB, interrupt <-chan struct{}) error {
-	return dropIndex(db, acceptanceIndexKey, acceptanceIndexName, interrupt)
-}
+// DropAcceptanceIndex drops the acceptance index.
+func DropAcceptanceIndex() error {
+	dbTx, err := dbaccess.NewTx()
+	if err != nil {
+		return err
+	}
+	defer dbTx.RollbackUnlessClosed()
 
-// Key returns the database key to use for the index as a byte slice.
-//
-// This is part of the Indexer interface.
-func (idx *AcceptanceIndex) Key() []byte {
-	return acceptanceIndexKey
-}
+	err = dbaccess.DropAcceptanceIndex(dbTx)
+	if err != nil {
+		return err
+	}
 
-// Name returns the human-readable name of the index.
-//
-// This is part of the Indexer interface.
-func (idx *AcceptanceIndex) Name() string {
-	return acceptanceIndexName
-}
-
-// Create is invoked when the indexer manager determines the index needs
-// to be created for the first time. It creates the bucket for the
-// acceptance index.
-//
-// This is part of the Indexer interface.
-func (idx *AcceptanceIndex) Create(dbTx database.Tx) error {
-	_, err := dbTx.Metadata().CreateBucket(acceptanceIndexKey)
-	return err
+	return dbTx.Commit()
 }
 
 // Init initializes the hash-based acceptance index.
 //
 // This is part of the Indexer interface.
-func (idx *AcceptanceIndex) Init(db database.DB, dag *blockdag.BlockDAG) error {
-	idx.db = db
+func (idx *AcceptanceIndex) Init(dag *blockdag.BlockDAG) error {
 	idx.dag = dag
-	return nil
+	return idx.recover()
+}
+
+// recover attempts to insert any data that's missing from the
+// acceptance index.
+//
+// This is part of the Indexer interface.
+func (idx *AcceptanceIndex) recover() error {
+	dbTx, err := dbaccess.NewTx()
+	if err != nil {
+		return err
+	}
+	defer dbTx.RollbackUnlessClosed()
+
+	err = idx.dag.ForEachHash(func(hash daghash.Hash) error {
+		exists, err := dbaccess.HasAcceptanceData(dbTx, &hash)
+		if err != nil {
+			return err
+		}
+		if exists {
+			return nil
+		}
+		txAcceptanceData, err := idx.dag.TxsAcceptedByBlockHash(&hash)
+		if err != nil {
+			return err
+		}
+		return idx.ConnectBlock(dbTx, &hash, txAcceptanceData)
+	})
+	if err != nil {
+		return err
+	}
+
+	return dbTx.Commit()
 }
 
 // ConnectBlock is invoked by the index manager when a new block has been
 // connected to the DAG.
 //
 // This is part of the Indexer interface.
-func (idx *AcceptanceIndex) ConnectBlock(dbTx database.Tx, _ *util.Block, blockID uint64, _ *blockdag.BlockDAG,
-	txsAcceptanceData blockdag.MultiBlockTxsAcceptanceData, _ blockdag.MultiBlockTxsAcceptanceData) error {
-	return dbPutTxsAcceptanceData(dbTx, blockID, txsAcceptanceData)
-}
-
-// TxsAcceptanceData returns the acceptance data of all the transactions that
-// were accepted by the block with hash blockHash.
-func (idx *AcceptanceIndex) TxsAcceptanceData(blockHash *daghash.Hash) (blockdag.MultiBlockTxsAcceptanceData, error) {
-	var txsAcceptanceData blockdag.MultiBlockTxsAcceptanceData
-	err := idx.db.View(func(dbTx database.Tx) error {
-		var err error
-		txsAcceptanceData, err = dbFetchTxsAcceptanceDataByHash(dbTx, blockHash)
-		return err
-	})
-	if err != nil {
-		return nil, err
-	}
-	return txsAcceptanceData, nil
-}
-
-// Recover is invoked when the indexer wasn't turned on for several blocks
-// and the indexer needs to close the gaps.
-//
-// This is part of the Indexer interface.
-func (idx *AcceptanceIndex) Recover(dbTx database.Tx, currentBlockID, lastKnownBlockID uint64) error {
-	for blockID := currentBlockID + 1; blockID <= lastKnownBlockID; blockID++ {
-		hash, err := blockdag.DBFetchBlockHashByID(dbTx, currentBlockID)
-		if err != nil {
-			return err
-		}
-		txAcceptanceData, err := idx.dag.TxsAcceptedByBlockHash(hash)
-		if err != nil {
-			return err
-		}
-		err = idx.ConnectBlock(dbTx, nil, blockID, nil, txAcceptanceData, nil)
-		if err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-func dbPutTxsAcceptanceData(dbTx database.Tx, blockID uint64,
+func (idx *AcceptanceIndex) ConnectBlock(dbContext *dbaccess.TxContext, blockHash *daghash.Hash,
 	txsAcceptanceData blockdag.MultiBlockTxsAcceptanceData) error {
 	serializedTxsAcceptanceData, err := serializeMultiBlockTxsAcceptanceData(txsAcceptanceData)
 	if err != nil {
 		return err
 	}
-
-	bucket := dbTx.Metadata().Bucket(acceptanceIndexKey)
-	return bucket.Put(blockdag.SerializeBlockID(blockID), serializedTxsAcceptanceData)
+	return dbaccess.StoreAcceptanceData(dbContext, blockHash, serializedTxsAcceptanceData)
 }
 
-func dbFetchTxsAcceptanceDataByHash(dbTx database.Tx,
-	hash *daghash.Hash) (blockdag.MultiBlockTxsAcceptanceData, error) {
-
-	blockID, err := blockdag.DBFetchBlockIDByHash(dbTx, hash)
+// TxsAcceptanceData returns the acceptance data of all the transactions that
+// were accepted by the block with hash blockHash.
+func (idx *AcceptanceIndex) TxsAcceptanceData(blockHash *daghash.Hash) (blockdag.MultiBlockTxsAcceptanceData, error) {
+	serializedTxsAcceptanceData, err := dbaccess.FetchAcceptanceData(dbaccess.NoTx(), blockHash)
 	if err != nil {
 		return nil, err
 	}
-
-	return dbFetchTxsAcceptanceDataByID(dbTx, blockID)
-}
-
-func dbFetchTxsAcceptanceDataByID(dbTx database.Tx,
-	blockID uint64) (blockdag.MultiBlockTxsAcceptanceData, error) {
-	serializedBlockID := blockdag.SerializeBlockID(blockID)
-	bucket := dbTx.Metadata().Bucket(acceptanceIndexKey)
-	serializedTxsAcceptanceData := bucket.Get(serializedBlockID)
-	if serializedTxsAcceptanceData == nil {
-		return nil, errors.Errorf("no entry in the accpetance index for block id %d", blockID)
-	}
-
 	return deserializeMultiBlockTxsAcceptanceData(serializedTxsAcceptanceData)
 }
 

blockdag/indexers/acceptanceindex_test.go

@@ -3,7 +3,7 @@ package indexers
 import (
 	"github.com/kaspanet/kaspad/blockdag"
 	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
@@ -96,7 +96,7 @@ func TestAcceptanceIndexRecover(t *testing.T) {
 	}
 	defer os.RemoveAll(db1Path)
 
-	db1, err := database.Create("ffldb", db1Path, params.Net)
+	err = dbaccess.Open(db1Path)
 	if err != nil {
 		t.Fatalf("error creating db: %s", err)
 	}
@@ -104,10 +104,9 @@ func TestAcceptanceIndexRecover(t *testing.T) {
 	db1Config := blockdag.Config{
 		IndexManager: db1IndexManager,
 		DAGParams:    params,
-		DB:           db1,
 	}
 
-	db1DAG, teardown, err := blockdag.DAGSetup("", db1Config)
+	db1DAG, teardown, err := blockdag.DAGSetup("", false, db1Config)
 	if err != nil {
 		t.Fatalf("TestAcceptanceIndexRecover: Failed to setup DAG instance: %v", err)
 	}
@@ -130,11 +129,6 @@ func TestAcceptanceIndexRecover(t *testing.T) {
 		}
 	}
 
-	err = db1.FlushCache()
-	if err != nil {
-		t.Fatalf("Error flushing database to disk: %s", err)
-	}
-
 	db2Path, err := ioutil.TempDir("", "TestAcceptanceIndexRecover2")
 	if err != nil {
 		t.Fatalf("Error creating temporary directory: %s", err)
@@ -166,17 +160,20 @@ func TestAcceptanceIndexRecover(t *testing.T) {
 		t.Fatalf("Error fetching acceptance data: %s", err)
 	}
 
-	db2, err := database.Open("ffldb", db2Path, params.Net)
+	err = dbaccess.Close()
 	if err != nil {
-		t.Fatalf("Error opening database: %s", err)
+		t.Fatalf("Error closing the database: %s", err)
+	}
+	err = dbaccess.Open(db2Path)
+	if err != nil {
+		t.Fatalf("error creating db: %s", err)
 	}
 
 	db2Config := blockdag.Config{
 		DAGParams: params,
-		DB:        db2,
 	}
 
-	db2DAG, teardown, err := blockdag.DAGSetup("", db2Config)
+	db2DAG, teardown, err := blockdag.DAGSetup("", false, db2Config)
 	if err != nil {
 		t.Fatalf("TestAcceptanceIndexRecover: Failed to setup DAG instance: %v", err)
 	}
@@ -199,10 +196,6 @@ func TestAcceptanceIndexRecover(t *testing.T) {
 		}
 	}
 
-	err = db2.FlushCache()
-	if err != nil {
-		t.Fatalf("Error flushing database to disk: %s", err)
-	}
 	db3Path, err := ioutil.TempDir("", "TestAcceptanceIndexRecover3")
 	if err != nil {
 		t.Fatalf("Error creating temporary directory: %s", err)
@@ -213,9 +206,13 @@ func TestAcceptanceIndexRecover(t *testing.T) {
 		t.Fatalf("copyDirectory: %s", err)
 	}
 
-	db3, err := database.Open("ffldb", db3Path, params.Net)
+	err = dbaccess.Close()
 	if err != nil {
-		t.Fatalf("Error opening database: %s", err)
+		t.Fatalf("Error closing the database: %s", err)
+	}
+	err = dbaccess.Open(db3Path)
+	if err != nil {
+		t.Fatalf("error creating db: %s", err)
 	}
 
 	db3AcceptanceIndex := NewAcceptanceIndex()
@@ -223,10 +220,9 @@ func TestAcceptanceIndexRecover(t *testing.T) {
 	db3Config := blockdag.Config{
 		IndexManager: db3IndexManager,
 		DAGParams:    params,
-		DB:           db3,
 	}
 
-	_, teardown, err = blockdag.DAGSetup("", db3Config)
+	_, teardown, err = blockdag.DAGSetup("", false, db3Config)
 	if err != nil {
 		t.Fatalf("TestAcceptanceIndexRecover: Failed to setup DAG instance: %v", err)
 	}

blockdag/indexers/common.go

@@ -1,112 +0,0 @@
-// Copyright (c) 2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-/*
-Package indexers implements optional block DAG indexes.
-*/
-package indexers
-
-import (
-	"encoding/binary"
-	"github.com/kaspanet/kaspad/blockdag"
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/util"
-	"github.com/pkg/errors"
-)
-
-var (
-	// byteOrder is the preferred byte order used for serializing numeric
-	// fields for storage in the database.
-	byteOrder = binary.LittleEndian
-
-	// errInterruptRequested indicates that an operation was cancelled due
-	// to a user-requested interrupt.
-	errInterruptRequested = errors.New("interrupt requested")
-)
-
-// NeedsInputser provides a generic interface for an indexer to specify the it
-// requires the ability to look up inputs for a transaction.
-type NeedsInputser interface {
-	NeedsInputs() bool
-}
-
-// Indexer provides a generic interface for an indexer that is managed by an
-// index manager such as the Manager type provided by this package.
-type Indexer interface {
-	// Key returns the key of the index as a byte slice.
-	Key() []byte
-
-	// Name returns the human-readable name of the index.
-	Name() string
-
-	// Create is invoked when the indexer manager determines the index needs
-	// to be created for the first time.
-	Create(dbTx database.Tx) error
-
-	// Init is invoked when the index manager is first initializing the
-	// index. This differs from the Create method in that it is called on
-	// every load, including the case the index was just created.
-	Init(db database.DB, dag *blockdag.BlockDAG) error
-
-	// ConnectBlock is invoked when the index manager is notified that a new
-	// block has been connected to the DAG.
-	ConnectBlock(dbTx database.Tx,
-		block *util.Block,
-		blockID uint64,
-		dag *blockdag.BlockDAG,
-		acceptedTxsData blockdag.MultiBlockTxsAcceptanceData,
-		virtualTxsAcceptanceData blockdag.MultiBlockTxsAcceptanceData) error
-
-	// Recover is invoked when the indexer wasn't turned on for several blocks
-	// and the indexer needs to close the gaps.
-	Recover(dbTx database.Tx, currentBlockID, lastKnownBlockID uint64) error
-}
-
-// AssertError identifies an error that indicates an internal code consistency
-// issue and should be treated as a critical and unrecoverable error.
-type AssertError string
-
-// Error returns the assertion error as a huma-readable string and satisfies
-// the error interface.
-func (e AssertError) Error() string {
-	return "assertion failed: " + string(e)
-}
-
-// errDeserialize signifies that a problem was encountered when deserializing
-// data.
-type errDeserialize string
-
-// Error implements the error interface.
-func (e errDeserialize) Error() string {
-	return string(e)
-}
-
-// isDeserializeErr returns whether or not the passed error is an errDeserialize
-// error.
-func isDeserializeErr(err error) bool {
-	var deserializeErr errDeserialize
-	return errors.As(err, &deserializeErr)
-}
-
-// internalBucket is an abstraction over a database bucket. It is used to make
-// the code easier to test since it allows mock objects in the tests to only
-// implement these functions instead of everything a database.Bucket supports.
-type internalBucket interface {
-	Get(key []byte) []byte
-	Put(key []byte, value []byte) error
-	Delete(key []byte) error
-}
-
-// interruptRequested returns true when the provided channel has been closed.
-// This simplifies early shutdown slightly since the caller can just use an if
-// statement instead of a select.
-func interruptRequested(interrupted <-chan struct{}) bool {
-	select {
-	case <-interrupted:
-		return true
-	default:
-	}
-
-	return false
-}

blockdag/indexers/indexer.go

@@ -0,0 +1,28 @@
+// Copyright (c) 2016 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+/*
+Package indexers implements optional block DAG indexes.
+*/
+package indexers
+
+import (
+	"github.com/kaspanet/kaspad/blockdag"
+	"github.com/kaspanet/kaspad/dbaccess"
+	"github.com/kaspanet/kaspad/util/daghash"
+)
+
+// Indexer provides a generic interface for an indexer that is managed by an
+// index manager such as the Manager type provided by this package.
+type Indexer interface {
+	// Init is invoked when the index manager is first initializing the
+	// index.
+	Init(dag *blockdag.BlockDAG) error
+
+	// ConnectBlock is invoked when the index manager is notified that a new
+	// block has been connected to the DAG.
+	ConnectBlock(dbContext *dbaccess.TxContext,
+		blockHash *daghash.Hash,
+		acceptedTxsData blockdag.MultiBlockTxsAcceptanceData) error
+}

blockdag/indexers/manager.go

@@ -6,190 +6,30 @@ package indexers
 
 import (
 	"github.com/kaspanet/kaspad/blockdag"
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/util"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util/daghash"
 )
 
-var (
-	// indexTipsBucketName is the name of the db bucket used to house the
-	// current tip of each index.
-	indexTipsBucketName = []byte("idxtips")
-
-	indexCurrentBlockIDBucketName = []byte("idxcurrentblockid")
-)
-
 // Manager defines an index manager that manages multiple optional indexes and
 // implements the blockdag.IndexManager interface so it can be seamlessly
 // plugged into normal DAG processing.
 type Manager struct {
-	db             database.DB
 	enabledIndexes []Indexer
 }
 
 // Ensure the Manager type implements the blockdag.IndexManager interface.
 var _ blockdag.IndexManager = (*Manager)(nil)
 
-// indexDropKey returns the key for an index which indicates it is in the
-// process of being dropped.
-func indexDropKey(idxKey []byte) []byte {
-	dropKey := make([]byte, len(idxKey)+1)
-	dropKey[0] = 'd'
-	copy(dropKey[1:], idxKey)
-	return dropKey
-}
-
-// maybeFinishDrops determines if each of the enabled indexes are in the middle
-// of being dropped and finishes dropping them when the are. This is necessary
-// because dropping and index has to be done in several atomic steps rather than
-// one big atomic step due to the massive number of entries.
-func (m *Manager) maybeFinishDrops(interrupt <-chan struct{}) error {
-	indexNeedsDrop := make([]bool, len(m.enabledIndexes))
-	err := m.db.View(func(dbTx database.Tx) error {
-		// None of the indexes needs to be dropped if the index tips
-		// bucket hasn't been created yet.
-		indexesBucket := dbTx.Metadata().Bucket(indexTipsBucketName)
-		if indexesBucket == nil {
-			return nil
-		}
-
-		// Mark the indexer as requiring a drop if one is already in
-		// progress.
-		for i, indexer := range m.enabledIndexes {
-			dropKey := indexDropKey(indexer.Key())
-			if indexesBucket.Get(dropKey) != nil {
-				indexNeedsDrop[i] = true
-			}
-		}
-
-		return nil
-	})
-	if err != nil {
-		return err
-	}
-
-	if interruptRequested(interrupt) {
-		return errInterruptRequested
-	}
-
-	// Finish dropping any of the enabled indexes that are already in the
-	// middle of being dropped.
-	for i, indexer := range m.enabledIndexes {
-		if !indexNeedsDrop[i] {
-			continue
-		}
-
-		log.Infof("Resuming %s drop", indexer.Name())
-		err := dropIndex(m.db, indexer.Key(), indexer.Name(), interrupt)
-		if err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-// maybeCreateIndexes determines if each of the enabled indexes have already
-// been created and creates them if not.
-func (m *Manager) maybeCreateIndexes(dbTx database.Tx) error {
-	indexesBucket := dbTx.Metadata().Bucket(indexTipsBucketName)
-	for _, indexer := range m.enabledIndexes {
-		// Nothing to do if the index tip already exists.
-		idxKey := indexer.Key()
-		if indexesBucket.Get(idxKey) != nil {
-			continue
-		}
-
-		// The tip for the index does not exist, so create it and
-		// invoke the create callback for the index so it can perform
-		// any one-time initialization it requires.
-		if err := indexer.Create(dbTx); err != nil {
-			return err
-		}
-
-		// TODO (Mike): this is temporary solution to prevent node from not starting
-		// because it thinks indexers are not initialized.
-		// Indexers, however, do not work properly, and a general solution to their work operation is required
-		indexesBucket.Put(idxKey, []byte{0})
-	}
-
-	return nil
-}
-
-// Init initializes the enabled indexes. This is called during DAG
-// initialization and primarily consists of catching up all indexes to the
-// current tips. This is necessary since each index can be disabled
-// and re-enabled at any time and attempting to catch-up indexes at the same
-// time new blocks are being downloaded would lead to an overall longer time to
-// catch up due to the I/O contention.
-//
+// Init initializes the enabled indexes.
 // This is part of the blockdag.IndexManager interface.
-func (m *Manager) Init(db database.DB, blockDAG *blockdag.BlockDAG, interrupt <-chan struct{}) error {
-	// Nothing to do when no indexes are enabled.
-	if len(m.enabledIndexes) == 0 {
-		return nil
-	}
-
-	if interruptRequested(interrupt) {
-		return errInterruptRequested
-	}
-
-	m.db = db
-
-	// Finish and drops that were previously interrupted.
-	if err := m.maybeFinishDrops(interrupt); err != nil {
-		return err
-	}
-
-	// Create the initial state for the indexes as needed.
-	err := m.db.Update(func(dbTx database.Tx) error {
-		// Create the bucket for the current tips as needed.
-		meta := dbTx.Metadata()
-		_, err := meta.CreateBucketIfNotExists(indexTipsBucketName)
-		if err != nil {
-			return err
-		}
-		if _, err := meta.CreateBucketIfNotExists(indexCurrentBlockIDBucketName); err != nil {
-			return err
-		}
-
-		return m.maybeCreateIndexes(dbTx)
-	})
-	if err != nil {
-		return err
-	}
-
-	// Initialize each of the enabled indexes.
+func (m *Manager) Init(dag *blockdag.BlockDAG) error {
 	for _, indexer := range m.enabledIndexes {
-		if err := indexer.Init(db, blockDAG); err != nil {
+		if err := indexer.Init(dag); err != nil {
 			return err
 		}
 	}
 
-	return m.recoverIfNeeded()
-}
-
-// recoverIfNeeded checks if the node worked for some time
-// without one of the current enabled indexes, and if it's
-// the case, recovers the missing blocks from the index.
-func (m *Manager) recoverIfNeeded() error {
-	return m.db.Update(func(dbTx database.Tx) error {
-		lastKnownBlockID := blockdag.DBFetchCurrentBlockID(dbTx)
-		for _, indexer := range m.enabledIndexes {
-			serializedCurrentIdxBlockID := dbTx.Metadata().Bucket(indexCurrentBlockIDBucketName).Get(indexer.Key())
-			currentIdxBlockID := uint64(0)
-			if serializedCurrentIdxBlockID != nil {
-				currentIdxBlockID = blockdag.DeserializeBlockID(serializedCurrentIdxBlockID)
-			}
-			if lastKnownBlockID > currentIdxBlockID {
-				err := indexer.Recover(dbTx, currentIdxBlockID, lastKnownBlockID)
-				if err != nil {
-					return err
-				}
-			}
-		}
-		return nil
-	})
+	return nil
 }
 
 // ConnectBlock must be invoked when a block is added to the DAG. It
@@ -197,32 +37,13 @@ func (m *Manager) recoverIfNeeded() error {
 // checks, and invokes each indexer.
 //
 // This is part of the blockdag.IndexManager interface.
-func (m *Manager) ConnectBlock(dbTx database.Tx, block *util.Block, blockID uint64, dag *blockdag.BlockDAG,
-	txsAcceptanceData blockdag.MultiBlockTxsAcceptanceData, virtualTxsAcceptanceData blockdag.MultiBlockTxsAcceptanceData) error {
+func (m *Manager) ConnectBlock(dbContext *dbaccess.TxContext, blockHash *daghash.Hash, txsAcceptanceData blockdag.MultiBlockTxsAcceptanceData) error {
 
 	// Call each of the currently active optional indexes with the block
 	// being connected so they can update accordingly.
 	for _, index := range m.enabledIndexes {
 		// Notify the indexer with the connected block so it can index it.
-		if err := index.ConnectBlock(dbTx, block, blockID, dag, txsAcceptanceData, virtualTxsAcceptanceData); err != nil {
-			return err
-		}
-	}
-
-	// Add the new block ID index entry for the block being connected and
-	// update the current internal block ID accordingly.
-	err := m.updateIndexersWithCurrentBlockID(dbTx, block.Hash(), blockID)
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
-func (m *Manager) updateIndexersWithCurrentBlockID(dbTx database.Tx, blockHash *daghash.Hash, blockID uint64) error {
-	serializedBlockID := blockdag.SerializeBlockID(blockID)
-	for _, index := range m.enabledIndexes {
-		err := dbTx.Metadata().Bucket(indexCurrentBlockIDBucketName).Put(index.Key(), serializedBlockID)
-		if err != nil {
+		if err := index.ConnectBlock(dbContext, blockHash, txsAcceptanceData); err != nil {
 			return err
 		}
 	}
@@ -238,155 +59,3 @@ func NewManager(enabledIndexes []Indexer) *Manager {
 		enabledIndexes: enabledIndexes,
 	}
 }
-
-// dropIndex drops the passed index from the database. Since indexes can be
-// massive, it deletes the index in multiple database transactions in order to
-// keep memory usage to reasonable levels. It also marks the drop in progress
-// so the drop can be resumed if it is stopped before it is done before the
-// index can be used again.
-func dropIndex(db database.DB, idxKey []byte, idxName string, interrupt <-chan struct{}) error {
-	// Nothing to do if the index doesn't already exist.
-	var needsDelete bool
-	err := db.View(func(dbTx database.Tx) error {
-		indexesBucket := dbTx.Metadata().Bucket(indexTipsBucketName)
-		if indexesBucket != nil && indexesBucket.Get(idxKey) != nil {
-			needsDelete = true
-		}
-		return nil
-	})
-	if err != nil {
-		return err
-	}
-	if !needsDelete {
-		log.Infof("Not dropping %s because it does not exist", idxName)
-		return nil
-	}
-
-	// Mark that the index is in the process of being dropped so that it
-	// can be resumed on the next start if interrupted before the process is
-	// complete.
-	log.Infof("Dropping all %s entries. This might take a while...",
-		idxName)
-	err = db.Update(func(dbTx database.Tx) error {
-		indexesBucket := dbTx.Metadata().Bucket(indexTipsBucketName)
-		return indexesBucket.Put(indexDropKey(idxKey), idxKey)
-	})
-	if err != nil {
-		return err
-	}
-
-	// Since the indexes can be so large, attempting to simply delete
-	// the bucket in a single database transaction would result in massive
-	// memory usage and likely crash many systems due to ulimits. In order
-	// to avoid this, use a cursor to delete a maximum number of entries out
-	// of the bucket at a time. Recurse buckets depth-first to delete any
-	// sub-buckets.
-	const maxDeletions = 2000000
-	var totalDeleted uint64
-
-	// Recurse through all buckets in the index, cataloging each for
-	// later deletion.
-	var subBuckets [][][]byte
-	var subBucketClosure func(database.Tx, []byte, [][]byte) error
-	subBucketClosure = func(dbTx database.Tx,
-		subBucket []byte, tlBucket [][]byte) error {
-		// Get full bucket name and append to subBuckets for later
-		// deletion.
-		var bucketName [][]byte
-		if (tlBucket == nil) || (len(tlBucket) == 0) {
-			bucketName = append(bucketName, subBucket)
-		} else {
-			bucketName = append(tlBucket, subBucket)
-		}
-		subBuckets = append(subBuckets, bucketName)
-		// Recurse sub-buckets to append to subBuckets slice.
-		bucket := dbTx.Metadata()
-		for _, subBucketName := range bucketName {
-			bucket = bucket.Bucket(subBucketName)
-		}
-		return bucket.ForEachBucket(func(k []byte) error {
-			return subBucketClosure(dbTx, k, bucketName)
-		})
-	}
-
-	// Call subBucketClosure with top-level bucket.
-	err = db.View(func(dbTx database.Tx) error {
-		return subBucketClosure(dbTx, idxKey, nil)
-	})
-	if err != nil {
-		return nil
-	}
-
-	// Iterate through each sub-bucket in reverse, deepest-first, deleting
-	// all keys inside them and then dropping the buckets themselves.
-	for i := range subBuckets {
-		bucketName := subBuckets[len(subBuckets)-1-i]
-		// Delete maxDeletions key/value pairs at a time.
-		for numDeleted := maxDeletions; numDeleted == maxDeletions; {
-			numDeleted = 0
-			err := db.Update(func(dbTx database.Tx) error {
-				subBucket := dbTx.Metadata()
-				for _, subBucketName := range bucketName {
-					subBucket = subBucket.Bucket(subBucketName)
-				}
-				cursor := subBucket.Cursor()
-				for ok := cursor.First(); ok; ok = cursor.Next() &&
-					numDeleted < maxDeletions {
-
-					if err := cursor.Delete(); err != nil {
-						return err
-					}
-					numDeleted++
-				}
-				return nil
-			})
-			if err != nil {
-				return err
-			}
-
-			if numDeleted > 0 {
-				totalDeleted += uint64(numDeleted)
-				log.Infof("Deleted %d keys (%d total) from %s",
-					numDeleted, totalDeleted, idxName)
-			}
-		}
-
-		if interruptRequested(interrupt) {
-			return errInterruptRequested
-		}
-
-		// Drop the bucket itself.
-		err = db.Update(func(dbTx database.Tx) error {
-			bucket := dbTx.Metadata()
-			for j := 0; j < len(bucketName)-1; j++ {
-				bucket = bucket.Bucket(bucketName[j])
-			}
-			return bucket.DeleteBucket(bucketName[len(bucketName)-1])
-		})
-		if err != nil {
-			return err
-		}
-	}
-
-	// Remove the index tip, index bucket, and in-progress drop flag now
-	// that all index entries have been removed.
-	err = db.Update(func(dbTx database.Tx) error {
-		meta := dbTx.Metadata()
-		indexesBucket := meta.Bucket(indexTipsBucketName)
-		if err := indexesBucket.Delete(idxKey); err != nil {
-			return err
-		}
-
-		if err := meta.Bucket(indexCurrentBlockIDBucketName).Delete(idxKey); err != nil {
-			return err
-		}
-
-		return indexesBucket.Delete(indexDropKey(idxKey))
-	})
-	if err != nil {
-		return err
-	}
-
-	log.Infof("Dropped %s", idxName)
-	return nil
-}

blockdag/mediantime.go

@@ -1,206 +0,0 @@
-// Copyright (c) 2013-2014 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package blockdag
-
-import (
-	"math"
-	"sort"
-	"sync"
-	"time"
-)
-
-const (
-	// maxAllowedOffsetSeconds is the maximum number of seconds in either
-	// direction that local clock will be adjusted. When the median time
-	// of the network is outside of this range, no offset will be applied.
-	maxAllowedOffsetSecs = 70 * 60 // 1 hour 10 minutes
-
-	// similarTimeSecs is the number of seconds in either direction from the
-	// local clock that is used to determine that it is likley wrong and
-	// hence to show a warning.
-	similarTimeSecs = 5 * 60 // 5 minutes
-)
-
-var (
-	// maxMedianTimeEntries is the maximum number of entries allowed in the
-	// median time data. This is a variable as opposed to a constant so the
-	// test code can modify it.
-	maxMedianTimeEntries = 200
-)
-
-// MedianTimeSource provides a mechanism to add several time samples which are
-// used to determine a median time which is then used as an offset to the local
-// clock.
-type MedianTimeSource interface {
-	// AdjustedTime returns the current time adjusted by the median time
-	// offset as calculated from the time samples added by AddTimeSample.
-	AdjustedTime() time.Time
-
-	// AddTimeSample adds a time sample that is used when determining the
-	// median time of the added samples.
-	AddTimeSample(id string, timeVal time.Time)
-
-	// Offset returns the number of seconds to adjust the local clock based
-	// upon the median of the time samples added by AddTimeData.
-	Offset() time.Duration
-}
-
-// int64Sorter implements sort.Interface to allow a slice of 64-bit integers to
-// be sorted.
-type int64Sorter []int64
-
-// Len returns the number of 64-bit integers in the slice. It is part of the
-// sort.Interface implementation.
-func (s int64Sorter) Len() int {
-	return len(s)
-}
-
-// Swap swaps the 64-bit integers at the passed indices. It is part of the
-// sort.Interface implementation.
-func (s int64Sorter) Swap(i, j int) {
-	s[i], s[j] = s[j], s[i]
-}
-
-// Less returns whether the 64-bit integer with index i should sort before the
-// 64-bit integer with index j. It is part of the sort.Interface
-// implementation.
-func (s int64Sorter) Less(i, j int) bool {
-	return s[i] < s[j]
-}
-
-// medianTime provides an implementation of the MedianTimeSource interface.
-type medianTime struct {
-	mtx                sync.Mutex
-	knownIDs           map[string]struct{}
-	offsets            []int64
-	offsetSecs         int64
-	invalidTimeChecked bool
-}
-
-// Ensure the medianTime type implements the MedianTimeSource interface.
-var _ MedianTimeSource = (*medianTime)(nil)
-
-// AdjustedTime returns the current time adjusted by the median time offset as
-// calculated from the time samples added by AddTimeSample.
-//
-// This function is safe for concurrent access and is part of the
-// MedianTimeSource interface implementation.
-func (m *medianTime) AdjustedTime() time.Time {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	// Limit the adjusted time to 1 second precision.
-	now := time.Unix(time.Now().Unix(), 0)
-	return now.Add(time.Duration(m.offsetSecs) * time.Second)
-}
-
-// AddTimeSample adds a time sample that is used when determining the median
-// time of the added samples.
-//
-// This function is safe for concurrent access and is part of the
-// MedianTimeSource interface implementation.
-func (m *medianTime) AddTimeSample(sourceID string, timeVal time.Time) {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	// Don't add time data from the same source.
-	if _, exists := m.knownIDs[sourceID]; exists {
-		return
-	}
-	m.knownIDs[sourceID] = struct{}{}
-
-	// Truncate the provided offset to seconds and append it to the slice
-	// of offsets while respecting the maximum number of allowed entries by
-	// replacing the oldest entry with the new entry once the maximum number
-	// of entries is reached.
-	now := time.Unix(time.Now().Unix(), 0)
-	offsetSecs := int64(timeVal.Sub(now).Seconds())
-	numOffsets := len(m.offsets)
-	if numOffsets == maxMedianTimeEntries && maxMedianTimeEntries > 0 {
-		m.offsets = m.offsets[1:]
-		numOffsets--
-	}
-	m.offsets = append(m.offsets, offsetSecs)
-	numOffsets++
-
-	// Sort the offsets so the median can be obtained as needed later.
-	sortedOffsets := make([]int64, numOffsets)
-	copy(sortedOffsets, m.offsets)
-	sort.Sort(int64Sorter(sortedOffsets))
-
-	offsetDuration := time.Duration(offsetSecs) * time.Second
-	log.Debugf("Added time sample of %s (total: %d)", offsetDuration,
-		numOffsets)
-
-	// The median offset is only updated when there are enough offsets and
-	// the number of offsets is odd so the middle value is the true median.
-	// Thus, there is nothing to do when those conditions are not met.
-	if numOffsets < 5 || numOffsets&0x01 != 1 {
-		return
-	}
-
-	// At this point the number of offsets in the list is odd, so the
-	// middle value of the sorted offsets is the median.
-	median := sortedOffsets[numOffsets/2]
-
-	// Set the new offset when the median offset is within the allowed
-	// offset range.
-	if math.Abs(float64(median)) < maxAllowedOffsetSecs {
-		m.offsetSecs = median
-	} else {
-		// The median offset of all added time data is larger than the
-		// maximum allowed offset, so don't use an offset. This
-		// effectively limits how far the local clock can be skewed.
-		m.offsetSecs = 0
-
-		if !m.invalidTimeChecked {
-			m.invalidTimeChecked = true
-
-			// Find if any time samples have a time that is close
-			// to the local time.
-			var remoteHasCloseTime bool
-			for _, offset := range sortedOffsets {
-				if math.Abs(float64(offset)) < similarTimeSecs {
-					remoteHasCloseTime = true
-					break
-				}
-			}
-
-			// Warn if none of the time samples are close.
-			if !remoteHasCloseTime {
-				log.Warnf("Please check your date and time " +
-					"are correct!  kaspad will not work " +
-					"properly with an invalid time")
-			}
-		}
-	}
-
-	medianDuration := time.Duration(m.offsetSecs) * time.Second
-	log.Debugf("New time offset: %d", medianDuration)
-}
-
-// Offset returns the number of seconds to adjust the local clock based upon the
-// median of the time samples added by AddTimeData.
-//
-// This function is safe for concurrent access and is part of the
-// MedianTimeSource interface implementation.
-func (m *medianTime) Offset() time.Duration {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	return time.Duration(m.offsetSecs) * time.Second
-}
-
-// NewMedianTime returns a new instance of concurrency-safe implementation of
-// the MedianTimeSource interface. The returned implementation contains the
-// rules necessary for proper time handling in the DAG consensus rules and
-// expects the time samples to be added from the timestamp field of the version
-// message received from remote peers that successfully connect and negotiate.
-func NewMedianTime() MedianTimeSource {
-	return &medianTime{
-		knownIDs: make(map[string]struct{}),
-		offsets:  make([]int64, 0, maxMedianTimeEntries),
-	}
-}

blockdag/mediantime_test.go

@@ -1,102 +0,0 @@
-// Copyright (c) 2013-2017 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package blockdag
-
-import (
-	"strconv"
-	"testing"
-	"time"
-)
-
-// TestMedianTime tests the medianTime implementation.
-func TestMedianTime(t *testing.T) {
-	tests := []struct {
-		in         []int64
-		wantOffset int64
-		useDupID   bool
-	}{
-		// Not enough samples must result in an offset of 0.
-		{in: []int64{1}, wantOffset: 0},
-		{in: []int64{1, 2}, wantOffset: 0},
-		{in: []int64{1, 2, 3}, wantOffset: 0},
-		{in: []int64{1, 2, 3, 4}, wantOffset: 0},
-
-		// Various number of entries. The expected offset is only
-		// updated on odd number of elements.
-		{in: []int64{-13, 57, -4, -23, -12}, wantOffset: -12},
-		{in: []int64{55, -13, 61, -52, 39, 55}, wantOffset: 39},
-		{in: []int64{-62, -58, -30, -62, 51, -30, 15}, wantOffset: -30},
-		{in: []int64{29, -47, 39, 54, 42, 41, 8, -33}, wantOffset: 39},
-		{in: []int64{37, 54, 9, -21, -56, -36, 5, -11, -39}, wantOffset: -11},
-		{in: []int64{57, -28, 25, -39, 9, 63, -16, 19, -60, 25}, wantOffset: 9},
-		{in: []int64{-5, -4, -3, -2, -1}, wantOffset: -3, useDupID: true},
-
-		// The offset stops being updated once the max number of entries
-		// has been reached.
-		{in: []int64{-67, 67, -50, 24, 63, 17, 58, -14, 5, -32, -52}, wantOffset: 17},
-		{in: []int64{-67, 67, -50, 24, 63, 17, 58, -14, 5, -32, -52, 45}, wantOffset: 17},
-		{in: []int64{-67, 67, -50, 24, 63, 17, 58, -14, 5, -32, -52, 45, 4}, wantOffset: 17},
-
-		// Offsets that are too far away from the local time should
-		// be ignored.
-		{in: []int64{-4201, 4202, -4203, 4204, -4205}, wantOffset: 0},
-
-		// Exercise the condition where the median offset is greater
-		// than the max allowed adjustment, but there is at least one
-		// sample that is close enough to the current time to avoid
-		// triggering a warning about an invalid local clock.
-		{in: []int64{4201, 4202, 4203, 4204, -299}, wantOffset: 0},
-	}
-
-	// Modify the max number of allowed median time entries for these tests.
-	maxMedianTimeEntries = 10
-	defer func() { maxMedianTimeEntries = 200 }()
-
-	for i, test := range tests {
-		filter := NewMedianTime()
-		for j, offset := range test.in {
-			id := strconv.Itoa(j)
-			now := time.Unix(time.Now().Unix(), 0)
-			tOffset := now.Add(time.Duration(offset) * time.Second)
-			filter.AddTimeSample(id, tOffset)
-
-			// Ensure the duplicate IDs are ignored.
-			if test.useDupID {
-				// Modify the offsets to ensure the final median
-				// would be different if the duplicate is added.
-				tOffset = tOffset.Add(time.Duration(offset) *
-					time.Second)
-				filter.AddTimeSample(id, tOffset)
-			}
-		}
-
-		// Since it is possible that the time.Now call in AddTimeSample
-		// and the time.Now calls here in the tests will be off by one
-		// second, allow a fudge factor to compensate.
-		gotOffset := filter.Offset()
-		wantOffset := time.Duration(test.wantOffset) * time.Second
-		wantOffset2 := time.Duration(test.wantOffset-1) * time.Second
-		if gotOffset != wantOffset && gotOffset != wantOffset2 {
-			t.Errorf("Offset #%d: unexpected offset -- got %v, "+
-				"want %v or %v", i, gotOffset, wantOffset,
-				wantOffset2)
-			continue
-		}
-
-		// Since it is possible that the time.Now call in AdjustedTime
-		// and the time.Now call here in the tests will be off by one
-		// second, allow a fudge factor to compensate.
-		adjustedTime := filter.AdjustedTime()
-		now := time.Unix(time.Now().Unix(), 0)
-		wantTime := now.Add(filter.Offset())
-		wantTime2 := now.Add(filter.Offset() - time.Second)
-		if !adjustedTime.Equal(wantTime) && !adjustedTime.Equal(wantTime2) {
-			t.Errorf("AdjustedTime #%d: unexpected result -- got %v, "+
-				"want %v or %v", i, adjustedTime, wantTime,
-				wantTime2)
-			continue
-		}
-	}
-}

blockdag/mining.go

@@ -3,8 +3,10 @@ package blockdag
 import (
 	"bytes"
 	"encoding/binary"
+	"github.com/kaspanet/go-secp256k1"
 	"github.com/kaspanet/kaspad/txscript"
 	"github.com/kaspanet/kaspad/util"
+	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
 	"time"
 )
@@ -12,6 +14,8 @@ import (
 // BlockForMining returns a block with the given transactions
 // that points to the current DAG tips, that is valid from
 // all aspects except proof of work.
+//
+// This function MUST be called with the DAG state lock held (for reads).
 func (dag *BlockDAG) BlockForMining(transactions []*util.Tx) (*wire.MsgBlock, error) {
 	blockTimestamp := dag.NextBlockTime()
 	requiredDifficulty := dag.NextRequiredDifficulty(blockTimestamp)
@@ -34,18 +38,17 @@ func (dag *BlockDAG) BlockForMining(transactions []*util.Tx) (*wire.MsgBlock, er
 		msgBlock.AddTransaction(tx.MsgTx())
 	}
 
-	utxoWithTransactions, err := dag.UTXOSet().WithTransactions(msgBlock.Transactions, UnacceptedBlueScore, false)
+	multiset, err := dag.NextBlockMultiset(transactions)
 	if err != nil {
 		return nil, err
 	}
-	utxoCommitment := utxoWithTransactions.Multiset().Hash()
 
 	msgBlock.Header = wire.BlockHeader{
 		Version:              nextBlockVersion,
 		ParentHashes:         dag.TipHashes(),
 		HashMerkleRoot:       hashMerkleTree.Root(),
 		AcceptedIDMerkleRoot: acceptedIDMerkleRoot,
-		UTXOCommitment:       utxoCommitment,
+		UTXOCommitment:       (*daghash.Hash)(multiset.Finalize()),
 		Timestamp:            blockTimestamp,
 		Bits:                 requiredDifficulty,
 	}
@@ -53,6 +56,19 @@ func (dag *BlockDAG) BlockForMining(transactions []*util.Tx) (*wire.MsgBlock, er
 	return &msgBlock, nil
 }
 
+// NextBlockMultiset returns the multiset of an assumed next block
+// built on top of the current tips, with the given transactions.
+//
+// This function MUST be called with the DAG state lock held (for reads).
+func (dag *BlockDAG) NextBlockMultiset(transactions []*util.Tx) (*secp256k1.MultiSet, error) {
+	pastUTXO, selectedParentUTXO, txsAcceptanceData, err := dag.pastUTXO(&dag.virtual.blockNode)
+	if err != nil {
+		return nil, err
+	}
+
+	return dag.virtual.blockNode.calcMultiset(dag, transactions, txsAcceptanceData, selectedParentUTXO, pastUTXO)
+}
+
 // CoinbasePayloadExtraData returns coinbase payload extra data parameter
 // which is built from extra nonce and coinbase flags.
 func CoinbasePayloadExtraData(extraNonce uint64, coinbaseFlags string) ([]byte, error) {
@@ -101,7 +117,7 @@ func (dag *BlockDAG) NextBlockTime() time.Time {
 	// timestamp is truncated to a second boundary before comparison since a
 	// block timestamp does not supported a precision greater than one
 	// second.
-	newTimestamp := dag.AdjustedTime()
+	newTimestamp := dag.Now()
 	minTimestamp := dag.NextBlockMinimumTime()
 	if newTimestamp.Before(minTimestamp) {
 		newTimestamp = minTimestamp

blockdag/multisetio.go

@@ -0,0 +1,29 @@
+package blockdag
+
+import (
+	"encoding/binary"
+	"github.com/kaspanet/go-secp256k1"
+	"io"
+)
+
+const multisetPointSize = 32
+
+// serializeMultiset serializes an ECMH multiset.
+func serializeMultiset(w io.Writer, ms *secp256k1.MultiSet) error {
+	serialized := ms.Serialize()
+	err := binary.Write(w, byteOrder, serialized)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// deserializeMultiset deserializes an EMCH multiset.
+func deserializeMultiset(r io.Reader) (*secp256k1.MultiSet, error) {
+	serialized := &secp256k1.SerializedMultiSet{}
+	err := binary.Read(r, byteOrder, serialized[:])
+	if err != nil {
+		return nil, err
+	}
+	return secp256k1.DeserializeMultiSet(serialized)
+}

blockdag/multisetstore.go

@@ -0,0 +1,131 @@
+package blockdag
+
+import (
+	"bytes"
+	"github.com/kaspanet/go-secp256k1"
+	"github.com/kaspanet/kaspad/dbaccess"
+	"github.com/kaspanet/kaspad/util/daghash"
+	"github.com/kaspanet/kaspad/util/locks"
+	"github.com/pkg/errors"
+)
+
+type multisetStore struct {
+	dag    *BlockDAG
+	new    map[daghash.Hash]struct{}
+	loaded map[daghash.Hash]secp256k1.MultiSet
+	mtx    *locks.PriorityMutex
+}
+
+func newMultisetStore(dag *BlockDAG) *multisetStore {
+	return &multisetStore{
+		dag:    dag,
+		new:    make(map[daghash.Hash]struct{}),
+		loaded: make(map[daghash.Hash]secp256k1.MultiSet),
+	}
+}
+
+func (store *multisetStore) setMultiset(node *blockNode, ms *secp256k1.MultiSet) {
+	store.loaded[*node.hash] = *ms
+	store.addToNewBlocks(node.hash)
+}
+
+func (store *multisetStore) addToNewBlocks(blockHash *daghash.Hash) {
+	store.new[*blockHash] = struct{}{}
+}
+
+func multisetNotFoundError(blockHash *daghash.Hash) error {
+	return errors.Errorf("Couldn't find multiset data for block %s", blockHash)
+}
+
+func (store *multisetStore) multisetByBlockNode(node *blockNode) (*secp256k1.MultiSet, error) {
+	ms, exists := store.multisetByBlockHash(node.hash)
+	if !exists {
+		return nil, multisetNotFoundError(node.hash)
+	}
+	return ms, nil
+}
+
+func (store *multisetStore) multisetByBlockHash(hash *daghash.Hash) (*secp256k1.MultiSet, bool) {
+	ms, ok := store.loaded[*hash]
+	return &ms, ok
+}
+
+// flushToDB writes all new multiset data to the database.
+func (store *multisetStore) flushToDB(dbContext *dbaccess.TxContext) error {
+	if len(store.new) == 0 {
+		return nil
+	}
+
+	w := &bytes.Buffer{}
+	for hash := range store.new {
+		hash := hash // Copy hash to a new variable to avoid passing the same pointer
+
+		w.Reset()
+		ms, exists := store.loaded[hash]
+		if !exists {
+			return multisetNotFoundError(&hash)
+		}
+
+		err := serializeMultiset(w, &ms)
+		if err != nil {
+			return err
+		}
+
+		err = store.storeMultiset(dbContext, &hash, w.Bytes())
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (store *multisetStore) clearNewEntries() {
+	store.new = make(map[daghash.Hash]struct{})
+}
+
+func (store *multisetStore) init(dbContext dbaccess.Context) error {
+	cursor, err := dbaccess.MultisetCursor(dbContext)
+	if err != nil {
+		return err
+	}
+	defer cursor.Close()
+
+	for ok := cursor.First(); ok; ok = cursor.Next() {
+		key, err := cursor.Key()
+		if err != nil {
+			return err
+		}
+
+		hash, err := daghash.NewHash(key)
+		if err != nil {
+			return err
+		}
+
+		serializedMS, err := cursor.Value()
+		if err != nil {
+			return err
+		}
+
+		ms, err := deserializeMultiset(bytes.NewReader(serializedMS))
+		if err != nil {
+			return err
+		}
+
+		store.loaded[*hash] = *ms
+	}
+	return nil
+}
+
+// storeMultiset stores the multiset data to the database.
+func (store *multisetStore) storeMultiset(dbContext dbaccess.Context, blockHash *daghash.Hash, serializedMS []byte) error {
+	exists, err := dbaccess.HasMultiset(dbContext, blockHash)
+	if err != nil {
+		return err
+	}
+
+	if exists {
+		return errors.Errorf("Can't override an existing multiset database entry for block %s", blockHash)
+	}
+
+	return dbaccess.StoreMultiset(dbContext, blockHash, serializedMS)
+}

blockdag/notifications_test.go

@@ -19,7 +19,7 @@ func TestNotifications(t *testing.T) {
 	}
 
 	// Create a new database and dag instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("notifications", Config{
+	dag, teardownFunc, err := DAGSetup("notifications", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {

blockdag/process.go

@@ -264,7 +264,7 @@ func (dag *BlockDAG) maxDelayOfParents(parentHashes []*daghash.Hash) (delay time
 	for _, parentHash := range parentHashes {
 		if delayedParent, exists := dag.delayedBlocks[*parentHash]; exists {
 			isDelayed = true
-			parentDelay := delayedParent.processTime.Sub(dag.AdjustedTime())
+			parentDelay := delayedParent.processTime.Sub(dag.Now())
 			if parentDelay > delay {
 				delay = parentDelay
 			}

blockdag/process_test.go

@@ -11,7 +11,7 @@ import (
 )
 
 func TestProcessOrphans(t *testing.T) {
-	dag, teardownFunc, err := DAGSetup("TestProcessOrphans", Config{
+	dag, teardownFunc, err := DAGSetup("TestProcessOrphans", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
@@ -72,45 +72,35 @@ func TestProcessOrphans(t *testing.T) {
 	}
 }
 
-type fakeTimeSource struct {
-	time time.Time
-}
-
-func (fts *fakeTimeSource) AdjustedTime() time.Time {
-	return fts.time
-}
-
-func (fts *fakeTimeSource) AddTimeSample(_ string, _ time.Time) {
-}
-
-func (fts *fakeTimeSource) Offset() time.Duration {
-	return 0
-}
-
 func TestProcessDelayedBlocks(t *testing.T) {
 	// We use dag1 so we can build the test blocks with the proper
 	// block header (UTXO commitment, acceptedIDMerkleroot, etc), and
 	// then we use dag2 for the actual test.
-	dag1, teardownFunc, err := DAGSetup("TestProcessDelayedBlocks1", Config{
+	dag1, teardownFunc, err := DAGSetup("TestProcessDelayedBlocks1", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
 		t.Fatalf("Failed to setup DAG instance: %v", err)
 	}
-	defer teardownFunc()
+	isDAG1Open := true
+	defer func() {
+		if isDAG1Open {
+			teardownFunc()
+		}
+	}()
 
 	initialTime := dag1.dagParams.GenesisBlock.Header.Timestamp
 	// Here we use a fake time source that returns a timestamp
 	// one hour into the future to make delayedBlock artificially
 	// valid.
-	dag1.timeSource = &fakeTimeSource{initialTime.Add(time.Hour)}
+	dag1.timeSource = newFakeTimeSource(initialTime.Add(time.Hour))
 
 	delayedBlock, err := PrepareBlockForTest(dag1, []*daghash.Hash{dag1.dagParams.GenesisBlock.BlockHash()}, nil)
 	if err != nil {
 		t.Fatalf("error in PrepareBlockForTest: %s", err)
 	}
 
-	blockDelay := time.Duration(dag1.dagParams.TimestampDeviationTolerance+5) * time.Second
+	blockDelay := time.Duration(dag1.dagParams.TimestampDeviationTolerance*uint64(dag1.targetTimePerBlock)+5) * time.Second
 	delayedBlock.Header.Timestamp = initialTime.Add(blockDelay)
 
 	isOrphan, isDelayed, err := dag1.ProcessBlock(util.NewBlock(delayedBlock), BFNoPoWCheck)
@@ -131,18 +121,21 @@ func TestProcessDelayedBlocks(t *testing.T) {
 		t.Fatalf("error in PrepareBlockForTest: %s", err)
 	}
 
+	teardownFunc()
+	isDAG1Open = false
+
 	// Here the actual test begins. We add a delayed block and
 	// its child and check that they are not added to the DAG,
 	// and check that they're added only if we add a new block
 	// after the delayed block timestamp is valid.
-	dag2, teardownFunc2, err := DAGSetup("TestProcessDelayedBlocks2", Config{
+	dag2, teardownFunc2, err := DAGSetup("TestProcessDelayedBlocks2", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
 		t.Fatalf("Failed to setup DAG instance: %v", err)
 	}
 	defer teardownFunc2()
-	dag2.timeSource = &fakeTimeSource{initialTime}
+	dag2.timeSource = newFakeTimeSource(initialTime)
 
 	isOrphan, isDelayed, err = dag2.ProcessBlock(util.NewBlock(delayedBlock), BFNoPoWCheck)
 	if err != nil {
@@ -209,10 +202,13 @@ func TestProcessDelayedBlocks(t *testing.T) {
 	}
 
 	// We advance the clock to the point where delayedBlock timestamp is valid.
-	secondsUntilDelayedBlockIsValid := delayedBlock.Header.Timestamp.Unix() - int64(dag2.TimestampDeviationTolerance) - dag2.AdjustedTime().Unix() + 1
-	dag2.timeSource = &fakeTimeSource{initialTime.Add(time.Duration(secondsUntilDelayedBlockIsValid) * time.Second)}
+	deviationTolerance := int64(dag2.TimestampDeviationTolerance) * dag2.targetTimePerBlock
+	secondsUntilDelayedBlockIsValid := delayedBlock.Header.Timestamp.Unix() - deviationTolerance - dag2.Now().Unix() + 1
+	dag2.timeSource = newFakeTimeSource(initialTime.Add(time.Duration(secondsUntilDelayedBlockIsValid) * time.Second))
 
-	blockAfterDelay, err := PrepareBlockForTest(dag2, []*daghash.Hash{dag2.dagParams.GenesisBlock.BlockHash()}, nil)
+	blockAfterDelay, err := PrepareBlockForTest(dag2,
+		[]*daghash.Hash{dag2.dagParams.GenesisBlock.BlockHash()},
+		nil)
 	if err != nil {
 		t.Fatalf("error in PrepareBlockForTest: %s", err)
 	}

blockdag/reachability.go

@@ -311,7 +311,7 @@ func (rtn *reachabilityTreeNode) countSubtrees(subTreeSizeMap map[*reachabilityT
 		if len(current.children) == 0 {
 			// We reached a leaf
 			subTreeSizeMap[current] = 1
-		} else if calculatedChildrenCount[current] <= uint64(len(current.children)) {
+		} else if _, ok := subTreeSizeMap[current]; !ok {
 			// We haven't yet calculated the subtree size of
 			// the current node. Add all its children to the
 			// queue

blockdag/reachability_test.go

@@ -609,6 +609,46 @@ func TestReindexIntervalErrors(t *testing.T) {
 	}
 }
 
+func BenchmarkReindexInterval(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		b.StopTimer()
+		root := newReachabilityTreeNode(&blockNode{})
+
+		const subTreeSize = 70000
+		// We set the interval of the root to subTreeSize*2 because
+		// its first child gets half of the interval, so a reindex
+		// from the root should happen after adding subTreeSize
+		// nodes.
+		root.setInterval(newReachabilityInterval(0, subTreeSize*2))
+
+		currentTreeNode := root
+		for i := 0; i < subTreeSize; i++ {
+			childTreeNode := newReachabilityTreeNode(&blockNode{})
+			_, err := currentTreeNode.addChild(childTreeNode)
+			if err != nil {
+				b.Fatalf("addChild: %s", err)
+			}
+
+			currentTreeNode = childTreeNode
+		}
+
+		remainingIntervalBefore := *root.remainingInterval
+		// After we added subTreeSize nodes, adding the next
+		// node should lead to a reindex from root.
+		fullReindexTriggeringNode := newReachabilityTreeNode(&blockNode{})
+		b.StartTimer()
+		_, err := currentTreeNode.addChild(fullReindexTriggeringNode)
+		b.StopTimer()
+		if err != nil {
+			b.Fatalf("addChild: %s", err)
+		}
+
+		if *root.remainingInterval == remainingIntervalBefore {
+			b.Fatal("Expected a reindex from root, but it didn't happen")
+		}
+	}
+}
+
 func TestFutureCoveringBlockSetString(t *testing.T) {
 	treeNodeA := newReachabilityTreeNode(&blockNode{})
 	treeNodeA.setInterval(newReachabilityInterval(123, 456))

blockdag/reachabilitystore.go

@@ -3,6 +3,7 @@ package blockdag
 import (
 	"bytes"
 	"github.com/kaspanet/kaspad/database"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
 	"github.com/pkg/errors"
@@ -82,7 +83,7 @@ func (store *reachabilityStore) reachabilityDataByHash(hash *daghash.Hash) (*rea
 }
 
 // flushToDB writes all dirty reachability data to the database.
-func (store *reachabilityStore) flushToDB(dbTx database.Tx) error {
+func (store *reachabilityStore) flushToDB(dbContext *dbaccess.TxContext) error {
 	if len(store.dirty) == 0 {
 		return nil
 	}
@@ -90,7 +91,7 @@ func (store *reachabilityStore) flushToDB(dbTx database.Tx) error {
 	for hash := range store.dirty {
 		hash := hash // Copy hash to a new variable to avoid passing the same pointer
 		reachabilityData := store.loaded[hash]
-		err := store.dbStoreReachabilityData(dbTx, &hash, reachabilityData)
+		err := store.storeReachabilityData(dbContext, &hash, reachabilityData)
 		if err != nil {
 			return err
 		}
@@ -102,22 +103,25 @@ func (store *reachabilityStore) clearDirtyEntries() {
 	store.dirty = make(map[daghash.Hash]struct{})
 }
 
-func (store *reachabilityStore) init(dbTx database.Tx) error {
-	bucket := dbTx.Metadata().Bucket(reachabilityDataBucketName)
-
+func (store *reachabilityStore) init(dbContext dbaccess.Context) error {
 	// TODO: (Stas) This is a quick and dirty hack.
 	// We iterate over the entire bucket twice:
 	// * First, populate the loaded set with all entries
 	// * Second, connect the parent/children pointers in each entry
 	//   with other nodes, which are now guaranteed to exist
-	cursor := bucket.Cursor()
+	cursor, err := dbaccess.ReachabilityDataCursor(dbContext)
+	if err != nil {
+		return err
+	}
+	defer cursor.Close()
+
 	for ok := cursor.First(); ok; ok = cursor.Next() {
 		err := store.initReachabilityData(cursor)
 		if err != nil {
 			return err
 		}
 	}
-	cursor = bucket.Cursor()
+
 	for ok := cursor.First(); ok; ok = cursor.Next() {
 		err := store.loadReachabilityDataFromCursor(cursor)
 		if err != nil {
@@ -128,7 +132,12 @@ func (store *reachabilityStore) init(dbTx database.Tx) error {
 }
 
 func (store *reachabilityStore) initReachabilityData(cursor database.Cursor) error {
-	hash, err := daghash.NewHash(cursor.Key())
+	key, err := cursor.Key()
+	if err != nil {
+		return err
+	}
+
+	hash, err := daghash.NewHash(key)
 	if err != nil {
 		return err
 	}
@@ -141,7 +150,12 @@ func (store *reachabilityStore) initReachabilityData(cursor database.Cursor) err
 }
 
 func (store *reachabilityStore) loadReachabilityDataFromCursor(cursor database.Cursor) error {
-	hash, err := daghash.NewHash(cursor.Key())
+	key, err := cursor.Key()
+	if err != nil {
+		return err
+	}
+
+	hash, err := daghash.NewHash(key)
 	if err != nil {
 		return err
 	}
@@ -151,7 +165,12 @@ func (store *reachabilityStore) loadReachabilityDataFromCursor(cursor database.C
 		return errors.Errorf("cannot find reachability data for block hash: %s", hash)
 	}
 
-	err = store.deserializeReachabilityData(cursor.Value(), reachabilityData)
+	serializedReachabilityData, err := cursor.Value()
+	if err != nil {
+		return err
+	}
+
+	err = store.deserializeReachabilityData(serializedReachabilityData, reachabilityData)
 	if err != nil {
 		return err
 	}
@@ -162,15 +181,15 @@ func (store *reachabilityStore) loadReachabilityDataFromCursor(cursor database.C
 	return nil
 }
 
-// dbStoreReachabilityData stores the reachability data to the database.
+// storeReachabilityData stores the reachability data to the database.
 // This overwrites the current entry if there exists one.
-func (store *reachabilityStore) dbStoreReachabilityData(dbTx database.Tx, hash *daghash.Hash, reachabilityData *reachabilityData) error {
+func (store *reachabilityStore) storeReachabilityData(dbContext dbaccess.Context, hash *daghash.Hash, reachabilityData *reachabilityData) error {
 	serializedReachabilyData, err := store.serializeReachabilityData(reachabilityData)
 	if err != nil {
 		return err
 	}
 
-	return dbTx.Metadata().Bucket(reachabilityDataBucketName).Put(hash[:], serializedReachabilyData)
+	return dbaccess.StoreReachabilityData(dbContext, hash, serializedReachabilyData)
 }
 
 func (store *reachabilityStore) serializeReachabilityData(reachabilityData *reachabilityData) ([]byte, error) {

blockdag/subnetworks.go

@@ -4,31 +4,20 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/pkg/errors"
 
 	"github.com/kaspanet/kaspad/util"
 
-	"github.com/kaspanet/kaspad/database"
 	"github.com/kaspanet/kaspad/util/subnetworkid"
 	"github.com/kaspanet/kaspad/wire"
 )
 
-// SubnetworkStore stores the subnetworks data
-type SubnetworkStore struct {
-	db database.DB
-}
-
-func newSubnetworkStore(db database.DB) *SubnetworkStore {
-	return &SubnetworkStore{
-		db: db,
-	}
-}
-
 // registerSubnetworks scans a list of transactions, singles out
 // subnetwork registry transactions, validates them, and registers a new
 // subnetwork based on it.
 // This function returns an error if one or more transactions are invalid
-func registerSubnetworks(dbTx database.Tx, txs []*util.Tx) error {
+func registerSubnetworks(dbContext dbaccess.Context, txs []*util.Tx) error {
 	subnetworkRegistryTxs := make([]*wire.MsgTx, 0)
 	for _, tx := range txs {
 		msgTx := tx.MsgTx()
@@ -50,13 +39,13 @@ func registerSubnetworks(dbTx database.Tx, txs []*util.Tx) error {
 		if err != nil {
 			return err
 		}
-		sNet, err := dbGetSubnetwork(dbTx, subnetworkID)
+		exists, err := dbaccess.HasSubnetwork(dbContext, subnetworkID)
 		if err != nil {
 			return err
 		}
-		if sNet == nil {
+		if !exists {
 			createdSubnetwork := newSubnetwork(registryTx)
-			err := dbRegisterSubnetwork(dbTx, subnetworkID, createdSubnetwork)
+			err := registerSubnetwork(dbContext, subnetworkID, createdSubnetwork)
 			if err != nil {
 				return errors.Errorf("failed registering subnetwork"+
 					"for tx '%s': %s", registryTx.TxHash(), err)
@@ -85,66 +74,39 @@ func TxToSubnetworkID(tx *wire.MsgTx) (*subnetworkid.SubnetworkID, error) {
 	return subnetworkid.New(util.Hash160(txHash[:]))
 }
 
-// subnetwork returns a registered subnetwork. If the subnetwork does not exist
-// this method returns an error.
-func (s *SubnetworkStore) subnetwork(subnetworkID *subnetworkid.SubnetworkID) (*subnetwork, error) {
-	var sNet *subnetwork
-	var err error
-	dbErr := s.db.View(func(dbTx database.Tx) error {
-		sNet, err = dbGetSubnetwork(dbTx, subnetworkID)
-		return nil
-	})
-	if dbErr != nil {
-		return nil, errors.Errorf("could not retrieve subnetwork '%d': %s", subnetworkID, dbErr)
-	}
+// fetchSubnetwork returns a registered subnetwork.
+func fetchSubnetwork(subnetworkID *subnetworkid.SubnetworkID) (*subnetwork, error) {
+	serializedSubnetwork, err := dbaccess.FetchSubnetworkData(dbaccess.NoTx(), subnetworkID)
 	if err != nil {
-		return nil, errors.Errorf("could not retrieve subnetwork '%d': %s", subnetworkID, err)
+		return nil, err
 	}
 
-	return sNet, nil
+	subnet, err := deserializeSubnetwork(serializedSubnetwork)
+	if err != nil {
+		return nil, err
+	}
+
+	return subnet, nil
 }
 
 // GasLimit returns the gas limit of a registered subnetwork. If the subnetwork does not
 // exist this method returns an error.
-func (s *SubnetworkStore) GasLimit(subnetworkID *subnetworkid.SubnetworkID) (uint64, error) {
-	sNet, err := s.subnetwork(subnetworkID)
+func GasLimit(subnetworkID *subnetworkid.SubnetworkID) (uint64, error) {
+	sNet, err := fetchSubnetwork(subnetworkID)
 	if err != nil {
 		return 0, err
 	}
-	if sNet == nil {
-		return 0, errors.Errorf("subnetwork '%s' not found", subnetworkID)
-	}
 
 	return sNet.gasLimit, nil
 }
 
-// dbRegisterSubnetwork stores mappings from ID of the subnetwork to the subnetwork data.
-func dbRegisterSubnetwork(dbTx database.Tx, subnetworkID *subnetworkid.SubnetworkID, network *subnetwork) error {
-	// Serialize the subnetwork
+func registerSubnetwork(dbContext dbaccess.Context, subnetworkID *subnetworkid.SubnetworkID, network *subnetwork) error {
 	serializedSubnetwork, err := serializeSubnetwork(network)
 	if err != nil {
 		return errors.Errorf("failed to serialize sub-netowrk '%s': %s", subnetworkID, err)
 	}
 
-	// Store the subnetwork
-	subnetworksBucket := dbTx.Metadata().Bucket(subnetworksBucketName)
-	err = subnetworksBucket.Put(subnetworkID[:], serializedSubnetwork)
-	if err != nil {
-		return errors.Errorf("failed to write sub-netowrk '%s': %s", subnetworkID, err)
-	}
-
-	return nil
-}
-
-// dbGetSubnetwork returns the subnetwork associated with subnetworkID or nil if the subnetwork was not found.
-func dbGetSubnetwork(dbTx database.Tx, subnetworkID *subnetworkid.SubnetworkID) (*subnetwork, error) {
-	bucket := dbTx.Metadata().Bucket(subnetworksBucketName)
-	serializedSubnetwork := bucket.Get(subnetworkID[:])
-	if serializedSubnetwork == nil {
-		return nil, nil
-	}
-
-	return deserializeSubnetwork(serializedSubnetwork)
+	return dbaccess.StoreSubnetwork(dbContext, subnetworkID, serializedSubnetwork)
 }
 
 type subnetwork struct {

blockdag/test_utils.go

@@ -5,9 +5,11 @@ package blockdag
 import (
 	"compress/bzip2"
 	"encoding/binary"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/pkg/errors"
 	"io"
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -16,34 +18,11 @@ import (
 
 	"github.com/kaspanet/kaspad/util/subnetworkid"
 
-	"github.com/kaspanet/kaspad/database"
-	_ "github.com/kaspanet/kaspad/database/ffldb" // blank import ffldb so that its init() function runs before tests
 	"github.com/kaspanet/kaspad/txscript"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
 )
 
-const (
-	// testDbType is the database backend type to use for the tests.
-	testDbType = "ffldb"
-
-	// blockDataNet is the expected network in the test block data.
-	blockDataNet = wire.Mainnet
-)
-
-// isSupportedDbType returns whether or not the passed database type is
-// currently supported.
-func isSupportedDbType(dbType string) bool {
-	supportedDrivers := database.SupportedDrivers()
-	for _, driver := range supportedDrivers {
-		if dbType == driver {
-			return true
-		}
-	}
-
-	return false
-}
-
 // FileExists returns whether or not the named file or directory exists.
 func FileExists(name string) bool {
 	if _, err := os.Stat(name); err != nil {
@@ -57,11 +36,10 @@ func FileExists(name string) bool {
 // DAGSetup is used to create a new db and DAG instance with the genesis
 // block already inserted. In addition to the new DAG instance, it returns
 // a teardown function the caller should invoke when done testing to clean up.
-func DAGSetup(dbName string, config Config) (*BlockDAG, func(), error) {
-	if !isSupportedDbType(testDbType) {
-		return nil, nil, errors.Errorf("unsupported db type %s", testDbType)
-	}
-
+// The openDB parameter instructs DAGSetup whether or not to also open the
+// database. Setting it to false is useful in tests that handle database
+// opening/closing by themselves.
+func DAGSetup(dbName string, openDb bool, config Config) (*BlockDAG, func(), error) {
 	var teardown func()
 
 	// To make sure that the teardown function is not called before any goroutines finished to run -
@@ -76,13 +54,16 @@ func DAGSetup(dbName string, config Config) (*BlockDAG, func(), error) {
 		})
 	}
 
-	if config.DB == nil {
-		tmpDir := os.TempDir()
+	if openDb {
+		var err error
+		tmpDir, err := ioutil.TempDir("", "DAGSetup")
+		if err != nil {
+			return nil, nil, errors.Errorf("error creating temp dir: %s", err)
+		}
 
 		dbPath := filepath.Join(tmpDir, dbName)
 		_ = os.RemoveAll(dbPath)
-		var err error
-		config.DB, err = database.Create(testDbType, dbPath, blockDataNet)
+		err = dbaccess.Open(dbPath)
 		if err != nil {
 			return nil, nil, errors.Errorf("error creating db: %s", err)
 		}
@@ -92,18 +73,17 @@ func DAGSetup(dbName string, config Config) (*BlockDAG, func(), error) {
 		teardown = func() {
 			spawnWaitGroup.Wait()
 			spawn = realSpawn
-			config.DB.Close()
+			dbaccess.Close()
 			os.RemoveAll(dbPath)
 		}
 	} else {
 		teardown = func() {
 			spawnWaitGroup.Wait()
 			spawn = realSpawn
-			config.DB.Close()
 		}
 	}
 
-	config.TimeSource = NewMedianTime()
+	config.TimeSource = NewTimeSource()
 	config.SigCache = txscript.NewSigCache(1000)
 
 	// Create the DAG instance.
@@ -173,7 +153,7 @@ func GetVirtualFromParentsForTest(dag *BlockDAG, parentHashes []*daghash.Hash) (
 	}
 	virtual := newVirtualBlock(dag, parents)
 
-	pastUTXO, _, err := dag.pastUTXO(&virtual.blockNode)
+	pastUTXO, _, _, err := dag.pastUTXO(&virtual.blockNode)
 	if err != nil {
 		return nil, err
 	}

blockdag/test_utils_test.go

@@ -1,14 +0,0 @@
-package blockdag
-
-import (
-	"testing"
-)
-
-func TestIsSupportedDbType(t *testing.T) {
-	if !isSupportedDbType("ffldb") {
-		t.Errorf("ffldb should be a supported DB driver")
-	}
-	if isSupportedDbType("madeUpDb") {
-		t.Errorf("madeUpDb should not be a supported DB driver")
-	}
-}

blockdag/timesource.go

@@ -0,0 +1,25 @@
+package blockdag
+
+import (
+	"time"
+)
+
+// TimeSource is the interface to access time.
+type TimeSource interface {
+	// Now returns the current time.
+	Now() time.Time
+}
+
+// timeSource provides an implementation of the TimeSource interface
+// that simply returns the current local time.
+type timeSource struct{}
+
+// Now returns the current local time, with one second precision.
+func (m *timeSource) Now() time.Time {
+	return time.Unix(time.Now().Unix(), 0)
+}
+
+// NewTimeSource returns a new instance of a TimeSource
+func NewTimeSource() TimeSource {
+	return &timeSource{}
+}

blockdag/utxo_ecmh.go

@@ -2,31 +2,26 @@ package blockdag
 
 import (
 	"bytes"
-	"github.com/golang/groupcache/lru"
-	"github.com/kaspanet/kaspad/ecc"
-	"github.com/kaspanet/kaspad/util/daghash"
+	"github.com/kaspanet/go-secp256k1"
 	"github.com/kaspanet/kaspad/wire"
 )
 
-const ecmhCacheSize = 4_000_000
-
-var (
-	utxoToECMHCache = lru.New(ecmhCacheSize)
-)
-
-func utxoMultiset(entry *UTXOEntry, outpoint *wire.Outpoint) (*ecc.Multiset, error) {
+func addUTXOToMultiset(ms *secp256k1.MultiSet, entry *UTXOEntry, outpoint *wire.Outpoint) (*secp256k1.MultiSet, error) {
 	w := &bytes.Buffer{}
 	err := serializeUTXO(w, entry, outpoint)
 	if err != nil {
 		return nil, err
 	}
-	serializedUTXO := w.Bytes()
-	utxoHash := daghash.DoubleHashH(serializedUTXO)
-
-	if cachedMSPoint, ok := utxoToECMHCache.Get(utxoHash); ok {
-		return cachedMSPoint.(*ecc.Multiset), nil
-	}
-	msPoint := ecc.NewMultiset(ecc.S256()).Add(serializedUTXO)
-	utxoToECMHCache.Add(utxoHash, msPoint)
-	return msPoint, nil
+	ms.Add(w.Bytes())
+	return ms, nil
+}
+
+func removeUTXOFromMultiset(ms *secp256k1.MultiSet, entry *UTXOEntry, outpoint *wire.Outpoint) (*secp256k1.MultiSet, error) {
+	w := &bytes.Buffer{}
+	err := serializeUTXO(w, entry, outpoint)
+	if err != nil {
+		return nil, err
+	}
+	ms.Remove(w.Bytes())
+	return ms, nil
 }

blockdag/utxodiffstore.go

@@ -2,14 +2,11 @@ package blockdag
 
 import (
 	"bytes"
-	"github.com/kaspanet/kaspad/database"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/util/locks"
-	"github.com/pkg/errors"
 )
 
-var multisetPointSize = 32
-
 type blockUTXODiffData struct {
 	diff      *UTXODiff
 	diffChild *blockNode
@@ -35,12 +32,11 @@ func (diffStore *utxoDiffStore) setBlockDiff(node *blockNode, diff *UTXODiff) er
 	diffStore.mtx.HighPriorityWriteLock()
 	defer diffStore.mtx.HighPriorityWriteUnlock()
 	// load the diff data from DB to diffStore.loaded
-	_, exists, err := diffStore.diffDataByHash(node.hash)
-	if err != nil {
-		return err
-	}
-	if !exists {
+	_, err := diffStore.diffDataByHash(node.hash)
+	if dbaccess.IsNotFoundError(err) {
 		diffStore.loaded[*node.hash] = &blockUTXODiffData{}
+	} else if err != nil {
+		return err
 	}
 
 	diffStore.loaded[*node.hash].diff = diff
@@ -52,22 +48,19 @@ func (diffStore *utxoDiffStore) setBlockDiffChild(node *blockNode, diffChild *bl
 	diffStore.mtx.HighPriorityWriteLock()
 	defer diffStore.mtx.HighPriorityWriteUnlock()
 	// load the diff data from DB to diffStore.loaded
-	_, exists, err := diffStore.diffDataByHash(node.hash)
+	_, err := diffStore.diffDataByHash(node.hash)
 	if err != nil {
 		return err
 	}
-	if !exists {
-		return diffNotFoundError(node)
-	}
 
 	diffStore.loaded[*node.hash].diffChild = diffChild
 	diffStore.setBlockAsDirty(node.hash)
 	return nil
 }
 
-func (diffStore *utxoDiffStore) removeBlocksDiffData(dbTx database.Tx, blockHashes []*daghash.Hash) error {
+func (diffStore *utxoDiffStore) removeBlocksDiffData(dbContext dbaccess.Context, blockHashes []*daghash.Hash) error {
 	for _, hash := range blockHashes {
-		err := diffStore.removeBlockDiffData(dbTx, hash)
+		err := diffStore.removeBlockDiffData(dbContext, hash)
 		if err != nil {
 			return err
 		}
@@ -75,11 +68,11 @@ func (diffStore *utxoDiffStore) removeBlocksDiffData(dbTx database.Tx, blockHash
 	return nil
 }
 
-func (diffStore *utxoDiffStore) removeBlockDiffData(dbTx database.Tx, blockHash *daghash.Hash) error {
+func (diffStore *utxoDiffStore) removeBlockDiffData(dbContext dbaccess.Context, blockHash *daghash.Hash) error {
 	diffStore.mtx.LowPriorityWriteLock()
 	defer diffStore.mtx.LowPriorityWriteUnlock()
 	delete(diffStore.loaded, *blockHash)
-	err := dbRemoveDiffData(dbTx, blockHash)
+	err := dbaccess.RemoveDiffData(dbContext, blockHash)
 	if err != nil {
 		return err
 	}
@@ -90,72 +83,49 @@ func (diffStore *utxoDiffStore) setBlockAsDirty(blockHash *daghash.Hash) {
 	diffStore.dirty[*blockHash] = struct{}{}
 }
 
-func (diffStore *utxoDiffStore) diffDataByHash(hash *daghash.Hash) (*blockUTXODiffData, bool, error) {
+func (diffStore *utxoDiffStore) diffDataByHash(hash *daghash.Hash) (*blockUTXODiffData, error) {
 	if diffData, ok := diffStore.loaded[*hash]; ok {
-		return diffData, true, nil
+		return diffData, nil
 	}
 	diffData, err := diffStore.diffDataFromDB(hash)
 	if err != nil {
-		return nil, false, err
+		return nil, err
 	}
-	exists := diffData != nil
-	if exists {
-		diffStore.loaded[*hash] = diffData
-	}
-	return diffData, exists, nil
-}
-
-func diffNotFoundError(node *blockNode) error {
-	return errors.Errorf("Couldn't find diff data for block %s", node.hash)
+	diffStore.loaded[*hash] = diffData
+	return diffData, nil
 }
 
 func (diffStore *utxoDiffStore) diffByNode(node *blockNode) (*UTXODiff, error) {
 	diffStore.mtx.HighPriorityReadLock()
 	defer diffStore.mtx.HighPriorityReadUnlock()
-	diffData, exists, err := diffStore.diffDataByHash(node.hash)
+	diffData, err := diffStore.diffDataByHash(node.hash)
 	if err != nil {
 		return nil, err
 	}
-	if !exists {
-		return nil, diffNotFoundError(node)
-	}
 	return diffData.diff, nil
 }
 
 func (diffStore *utxoDiffStore) diffChildByNode(node *blockNode) (*blockNode, error) {
 	diffStore.mtx.HighPriorityReadLock()
 	defer diffStore.mtx.HighPriorityReadUnlock()
-	diffData, exists, err := diffStore.diffDataByHash(node.hash)
+	diffData, err := diffStore.diffDataByHash(node.hash)
 	if err != nil {
 		return nil, err
 	}
-	if !exists {
-		return nil, diffNotFoundError(node)
-	}
 	return diffData.diffChild, nil
 }
 
 func (diffStore *utxoDiffStore) diffDataFromDB(hash *daghash.Hash) (*blockUTXODiffData, error) {
-	var diffData *blockUTXODiffData
-	err := diffStore.dag.db.View(func(dbTx database.Tx) error {
-		bucket := dbTx.Metadata().Bucket(utxoDiffsBucketName)
-		serializedBlockDiffData := bucket.Get(hash[:])
-		if serializedBlockDiffData != nil {
-			var err error
-			diffData, err = diffStore.deserializeBlockUTXODiffData(serializedBlockDiffData)
-			return err
-		}
-		return nil
-	})
+	serializedBlockDiffData, err := dbaccess.FetchUTXODiffData(dbaccess.NoTx(), hash)
 	if err != nil {
 		return nil, err
 	}
-	return diffData, nil
+
+	return diffStore.deserializeBlockUTXODiffData(serializedBlockDiffData)
 }
 
-// flushToDB writes all dirty diff data to the database. If all writes
-// succeed, this clears the dirty set.
-func (diffStore *utxoDiffStore) flushToDB(dbTx database.Tx) error {
+// flushToDB writes all dirty diff data to the database.
+func (diffStore *utxoDiffStore) flushToDB(dbContext *dbaccess.TxContext) error {
 	diffStore.mtx.HighPriorityWriteLock()
 	defer diffStore.mtx.HighPriorityWriteUnlock()
 	if len(diffStore.dirty) == 0 {
@@ -169,7 +139,7 @@ func (diffStore *utxoDiffStore) flushToDB(dbTx database.Tx) error {
 		hash := hash // Copy hash to a new variable to avoid passing the same pointer
 		buffer.Reset()
 		diffData := diffStore.loaded[hash]
-		err := dbStoreDiffData(dbTx, buffer, &hash, diffData)
+		err := storeDiffData(dbContext, buffer, &hash, diffData)
 		if err != nil {
 			return err
 		}
@@ -181,28 +151,18 @@ func (diffStore *utxoDiffStore) clearDirtyEntries() {
 	diffStore.dirty = make(map[daghash.Hash]struct{})
 }
 
-// dbStoreDiffData stores the UTXO diff data to the database.
+// storeDiffData stores the UTXO diff data to the database.
 // This overwrites the current entry if there exists one.
-func dbStoreDiffData(dbTx database.Tx, writeBuffer *bytes.Buffer, hash *daghash.Hash, diffData *blockUTXODiffData) error {
-	// To avoid a ton of allocs, use the given writeBuffer
+func storeDiffData(dbContext dbaccess.Context, w *bytes.Buffer, hash *daghash.Hash, diffData *blockUTXODiffData) error {
+	// To avoid a ton of allocs, use the io.Writer
 	// instead of allocating one. We expect the buffer to
 	// already be initalized and, in most cases, to already
 	// be large enough to accommodate the serialized data
 	// without growing.
-	err := serializeBlockUTXODiffData(writeBuffer, diffData)
+	err := serializeBlockUTXODiffData(w, diffData)
 	if err != nil {
 		return err
 	}
 
-	// Bucket.Put doesn't copy on its own, so we manually
-	// copy here. We do so because we expect the buffer
-	// to be reused once we're done with it.
-	serializedDiffData := make([]byte, writeBuffer.Len())
-	copy(serializedDiffData, writeBuffer.Bytes())
-
-	return dbTx.Metadata().Bucket(utxoDiffsBucketName).Put(hash[:], serializedDiffData)
-}
-
-func dbRemoveDiffData(dbTx database.Tx, hash *daghash.Hash) error {
-	return dbTx.Metadata().Bucket(utxoDiffsBucketName).Delete(hash[:])
+	return dbaccess.StoreUTXODiffData(dbContext, hash, w.Bytes())
 }

blockdag/utxodiffstore_test.go

@@ -1,9 +1,8 @@
 package blockdag
 
 import (
-	"fmt"
 	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
+	"github.com/kaspanet/kaspad/dbaccess"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
 	"reflect"
@@ -12,7 +11,7 @@ import (
 
 func TestUTXODiffStore(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("TestUTXODiffStore", Config{
+	dag, teardownFunc, err := DAGSetup("TestUTXODiffStore", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
@@ -31,9 +30,12 @@ func TestUTXODiffStore(t *testing.T) {
 	// Check that an error is returned when asking for non existing node
 	nonExistingNode := createNode()
 	_, err = dag.utxoDiffStore.diffByNode(nonExistingNode)
-	expectedErrString := fmt.Sprintf("Couldn't find diff data for block %s", nonExistingNode.hash)
-	if err == nil || err.Error() != expectedErrString {
-		t.Errorf("diffByNode: expected error %s but got %s", expectedErrString, err)
+	if !dbaccess.IsNotFoundError(err) {
+		if err != nil {
+			t.Errorf("diffByNode: %s", err)
+		} else {
+			t.Errorf("diffByNode: unexpectedly found diff data")
+		}
 	}
 
 	// Add node's diff data to the utxoDiffStore and check if it's checked correctly.
@@ -63,12 +65,19 @@ func TestUTXODiffStore(t *testing.T) {
 
 	// Flush changes to db, delete them from the dag.utxoDiffStore.loaded
 	// map, and check if the diff data is re-fetched from the database.
-	err = dag.db.Update(func(dbTx database.Tx) error {
-		return dag.utxoDiffStore.flushToDB(dbTx)
-	})
+	dbTx, err := dbaccess.NewTx()
+	if err != nil {
+		t.Fatalf("Failed to open database transaction: %s", err)
+	}
+	defer dbTx.RollbackUnlessClosed()
+	err = dag.utxoDiffStore.flushToDB(dbTx)
 	if err != nil {
 		t.Fatalf("Error flushing utxoDiffStore data to DB: %s", err)
 	}
+	err = dbTx.Commit()
+	if err != nil {
+		t.Fatalf("Failed to commit database transaction: %s", err)
+	}
 	delete(dag.utxoDiffStore.loaded, *node.hash)
 
 	if storeDiff, err := dag.utxoDiffStore.diffByNode(node); err != nil {

blockdag/utxoio.go

@@ -2,15 +2,11 @@ package blockdag
 
 import (
 	"bytes"
-	"encoding/binary"
-	"fmt"
-	"github.com/pkg/errors"
-	"io"
-	"math/big"
-
-	"github.com/kaspanet/kaspad/ecc"
+	"github.com/kaspanet/kaspad/util/binaryserializer"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
+	"github.com/pkg/errors"
+	"io"
 )
 
 // serializeBlockUTXODiffData serializes diff data in the following format:
@@ -54,40 +50,26 @@ func utxoEntryHeaderCode(entry *UTXOEntry) uint64 {
 	return headerCode
 }
 
-func (diffStore *utxoDiffStore) deserializeBlockUTXODiffData(serializedDiffDataBytes []byte) (*blockUTXODiffData, error) {
+func (diffStore *utxoDiffStore) deserializeBlockUTXODiffData(serializedDiffData []byte) (*blockUTXODiffData, error) {
 	diffData := &blockUTXODiffData{}
-	serializedDiffData := bytes.NewBuffer(serializedDiffDataBytes)
+	r := bytes.NewBuffer(serializedDiffData)
 
 	var hasDiffChild bool
-	err := wire.ReadElement(serializedDiffData, &hasDiffChild)
+	err := wire.ReadElement(r, &hasDiffChild)
 	if err != nil {
 		return nil, err
 	}
 
 	if hasDiffChild {
 		hash := &daghash.Hash{}
-		err := wire.ReadElement(serializedDiffData, hash)
+		err := wire.ReadElement(r, hash)
 		if err != nil {
 			return nil, err
 		}
 		diffData.diffChild = diffStore.dag.index.LookupNode(hash)
 	}
 
-	diffData.diff = &UTXODiff{
-		useMultiset: true,
-	}
-
-	diffData.diff.toAdd, err = deserializeDiffEntries(serializedDiffData)
-	if err != nil {
-		return nil, err
-	}
-
-	diffData.diff.toRemove, err = deserializeDiffEntries(serializedDiffData)
-	if err != nil {
-		return nil, err
-	}
-
-	diffData.diff.diffMultiset, err = deserializeMultiset(serializedDiffData)
+	diffData.diff, err = deserializeUTXODiff(r)
 	if err != nil {
 		return nil, err
 	}
@@ -95,38 +77,31 @@ func (diffStore *utxoDiffStore) deserializeBlockUTXODiffData(serializedDiffDataB
 	return diffData, nil
 }
 
-func deserializeDiffEntries(r io.Reader) (utxoCollection, error) {
+func deserializeUTXODiff(r io.Reader) (*UTXODiff, error) {
+	diff := &UTXODiff{}
+
+	var err error
+	diff.toAdd, err = deserializeUTXOCollection(r)
+	if err != nil {
+		return nil, err
+	}
+
+	diff.toRemove, err = deserializeUTXOCollection(r)
+	if err != nil {
+		return nil, err
+	}
+
+	return diff, nil
+}
+
+func deserializeUTXOCollection(r io.Reader) (utxoCollection, error) {
 	count, err := wire.ReadVarInt(r)
 	if err != nil {
 		return nil, err
 	}
 	collection := utxoCollection{}
 	for i := uint64(0); i < count; i++ {
-		outpointSize, err := wire.ReadVarInt(r)
-		if err != nil {
-			return nil, err
-		}
-
-		serializedOutpoint := make([]byte, outpointSize)
-		err = binary.Read(r, byteOrder, serializedOutpoint)
-		if err != nil {
-			return nil, err
-		}
-		outpoint, err := deserializeOutpoint(serializedOutpoint)
-		if err != nil {
-			return nil, err
-		}
-
-		utxoEntrySize, err := wire.ReadVarInt(r)
-		if err != nil {
-			return nil, err
-		}
-		serializedEntry := make([]byte, utxoEntrySize)
-		err = binary.Read(r, byteOrder, serializedEntry)
-		if err != nil {
-			return nil, err
-		}
-		utxoEntry, err := deserializeUTXOEntry(serializedEntry)
+		utxoEntry, outpoint, err := deserializeUTXO(r)
 		if err != nil {
 			return nil, err
 		}
@@ -135,31 +110,22 @@ func deserializeDiffEntries(r io.Reader) (utxoCollection, error) {
 	return collection, nil
 }
 
-// deserializeMultiset deserializes an EMCH multiset.
-// See serializeMultiset for more details.
-func deserializeMultiset(r io.Reader) (*ecc.Multiset, error) {
-	xBytes := make([]byte, multisetPointSize)
-	yBytes := make([]byte, multisetPointSize)
-	err := binary.Read(r, byteOrder, xBytes)
+func deserializeUTXO(r io.Reader) (*UTXOEntry, *wire.Outpoint, error) {
+	outpoint, err := deserializeOutpoint(r)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
-	err = binary.Read(r, byteOrder, yBytes)
+
+	utxoEntry, err := deserializeUTXOEntry(r)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
-	var x, y big.Int
-	x.SetBytes(xBytes)
-	y.SetBytes(yBytes)
-	return ecc.NewMultisetFromPoint(ecc.S256(), &x, &y), nil
+	return utxoEntry, outpoint, nil
 }
 
 // serializeUTXODiff serializes UTXODiff by serializing
 // UTXODiff.toAdd, UTXODiff.toRemove and UTXODiff.Multiset one after the other.
 func serializeUTXODiff(w io.Writer, diff *UTXODiff) error {
-	if !diff.useMultiset {
-		return errors.New("Cannot serialize a UTXO diff without a multiset")
-	}
 	err := serializeUTXOCollection(w, diff.toAdd)
 	if err != nil {
 		return err
@@ -169,10 +135,7 @@ func serializeUTXODiff(w io.Writer, diff *UTXODiff) error {
 	if err != nil {
 		return err
 	}
-	err = serializeMultiset(w, diff.diffMultiset)
-	if err != nil {
-		return err
-	}
+
 	return nil
 }
 
@@ -193,121 +156,95 @@ func serializeUTXOCollection(w io.Writer, collection utxoCollection) error {
 	return nil
 }
 
-// serializeMultiset serializes an ECMH multiset. The serialization
-// is done by taking the (x,y) coordinnates of the multiset point and
-// padding each one of them with 32 byte (it'll be 32 byte in most
-// cases anyway except one of the coordinates is zero) and writing
-// them one after the other.
-func serializeMultiset(w io.Writer, ms *ecc.Multiset) error {
-	x, y := ms.Point()
-	xBytes := make([]byte, multisetPointSize)
-	copy(xBytes, x.Bytes())
-	yBytes := make([]byte, multisetPointSize)
-	copy(yBytes, y.Bytes())
-
-	err := binary.Write(w, byteOrder, xBytes)
-	if err != nil {
-		return err
-	}
-	err = binary.Write(w, byteOrder, yBytes)
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
 // serializeUTXO serializes a utxo entry-outpoint pair
 func serializeUTXO(w io.Writer, entry *UTXOEntry, outpoint *wire.Outpoint) error {
-	serializedOutpoint := *outpointKey(*outpoint)
-	err := wire.WriteVarInt(w, uint64(len(serializedOutpoint)))
+	err := serializeOutpoint(w, outpoint)
 	if err != nil {
 		return err
 	}
 
-	err = binary.Write(w, byteOrder, serializedOutpoint)
-	if err != nil {
-		return err
-	}
-
-	serializedUTXOEntry := serializeUTXOEntry(entry)
-	err = wire.WriteVarInt(w, uint64(len(serializedUTXOEntry)))
-	if err != nil {
-		return err
-	}
-	err = binary.Write(w, byteOrder, serializedUTXOEntry)
+	err = serializeUTXOEntry(w, entry)
 	if err != nil {
 		return err
 	}
 	return nil
 }
 
-// serializeUTXOEntry returns the entry serialized to a format that is suitable
-// for long-term storage. The format is described in detail above.
-func serializeUTXOEntry(entry *UTXOEntry) []byte {
+// p2pkhUTXOEntrySerializeSize is the serialized size for a P2PKH UTXO entry.
+// 8 bytes (header code) + 8 bytes (amount) + varint for script pub key length of 25 (for P2PKH) + 25 bytes for P2PKH script.
+var p2pkhUTXOEntrySerializeSize = 8 + 8 + wire.VarIntSerializeSize(25) + 25
+
+// serializeUTXOEntry encodes the entry to the given io.Writer and use compression if useCompression is true.
+// The compression format is described in detail above.
+func serializeUTXOEntry(w io.Writer, entry *UTXOEntry) error {
 	// Encode the header code.
 	headerCode := utxoEntryHeaderCode(entry)
 
-	// Calculate the size needed to serialize the entry.
-	size := serializeSizeVLQ(headerCode) +
-		compressedTxOutSize(uint64(entry.Amount()), entry.ScriptPubKey())
-
-	// Serialize the header code followed by the compressed unspent
-	// transaction output.
-	serialized := make([]byte, size)
-	offset := putVLQ(serialized, headerCode)
-	offset += putCompressedTxOut(serialized[offset:], uint64(entry.Amount()),
-		entry.ScriptPubKey())
-
-	return serialized
-}
-
-// deserializeOutpoint decodes an outpoint from the passed serialized byte
-// slice into a new wire.Outpoint using a format that is suitable for long-
-// term storage. this format is described in detail above.
-func deserializeOutpoint(serialized []byte) (*wire.Outpoint, error) {
-	if len(serialized) <= daghash.HashSize {
-		return nil, errDeserialize("unexpected end of data")
+	err := binaryserializer.PutUint64(w, byteOrder, headerCode)
+	if err != nil {
+		return err
 	}
 
-	txID := daghash.TxID{}
-	txID.SetBytes(serialized[:daghash.HashSize])
-	index, _ := deserializeVLQ(serialized[daghash.HashSize:])
-	return wire.NewOutpoint(&txID, uint32(index)), nil
+	err = binaryserializer.PutUint64(w, byteOrder, entry.Amount())
+	if err != nil {
+		return err
+	}
+
+	err = wire.WriteVarInt(w, uint64(len(entry.ScriptPubKey())))
+	if err != nil {
+		return err
+	}
+
+	_, err = w.Write(entry.ScriptPubKey())
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
 }
 
-// deserializeUTXOEntry decodes a UTXO entry from the passed serialized byte
-// slice into a new UTXOEntry using a format that is suitable for long-term
-// storage. The format is described in detail above.
-func deserializeUTXOEntry(serialized []byte) (*UTXOEntry, error) {
+// deserializeUTXOEntry decodes a UTXO entry from the passed reader
+// into a new UTXOEntry. If isCompressed is used it will decompress
+// the entry according to the format that is described in detail
+// above.
+func deserializeUTXOEntry(r io.Reader) (*UTXOEntry, error) {
 	// Deserialize the header code.
-	code, offset := deserializeVLQ(serialized)
-	if offset >= len(serialized) {
-		return nil, errDeserialize("unexpected end of data after header")
+	headerCode, err := binaryserializer.Uint64(r, byteOrder)
+	if err != nil {
+		return nil, err
 	}
 
 	// Decode the header code.
 	//
 	// Bit 0 indicates whether the containing transaction is a coinbase.
 	// Bits 1-x encode blue score of the containing transaction.
-	isCoinbase := code&0x01 != 0
-	blockBlueScore := code >> 1
-
-	// Decode the compressed unspent transaction output.
-	amount, scriptPubKey, _, err := decodeCompressedTxOut(serialized[offset:])
-	if err != nil {
-		return nil, errDeserialize(fmt.Sprintf("unable to decode "+
-			"UTXO: %s", err))
-	}
+	isCoinbase := headerCode&0x01 != 0
+	blockBlueScore := headerCode >> 1
 
 	entry := &UTXOEntry{
-		amount:         amount,
-		scriptPubKey:   scriptPubKey,
 		blockBlueScore: blockBlueScore,
 		packedFlags:    0,
 	}
+
 	if isCoinbase {
 		entry.packedFlags |= tfCoinbase
 	}
 
+	entry.amount, err = binaryserializer.Uint64(r, byteOrder)
+	if err != nil {
+		return nil, err
+	}
+
+	scriptPubKeyLen, err := wire.ReadVarInt(r)
+	if err != nil {
+		return nil, err
+	}
+
+	entry.scriptPubKey = make([]byte, scriptPubKeyLen)
+	_, err = r.Read(entry.scriptPubKey)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
 	return entry, nil
 }

blockdag/utxoset.go

@@ -8,7 +8,7 @@ import (
 
 	"github.com/pkg/errors"
 
-	"github.com/kaspanet/kaspad/ecc"
+	"github.com/kaspanet/go-secp256k1"
 	"github.com/kaspanet/kaspad/wire"
 )
 
@@ -153,29 +153,16 @@ func (uc utxoCollection) clone() utxoCollection {
 
 // UTXODiff represents a diff between two UTXO Sets.
 type UTXODiff struct {
-	toAdd        utxoCollection
-	toRemove     utxoCollection
-	diffMultiset *ecc.Multiset
-	useMultiset  bool
+	toAdd    utxoCollection
+	toRemove utxoCollection
 }
 
-// NewUTXODiffWithoutMultiset creates a new, empty utxoDiff
+// NewUTXODiff creates a new, empty utxoDiff
 // without a multiset.
-func NewUTXODiffWithoutMultiset() *UTXODiff {
-	return &UTXODiff{
-		toAdd:       utxoCollection{},
-		toRemove:    utxoCollection{},
-		useMultiset: false,
-	}
-}
-
-// NewUTXODiff creates a new, empty utxoDiff.
 func NewUTXODiff() *UTXODiff {
 	return &UTXODiff{
-		toAdd:        utxoCollection{},
-		toRemove:     utxoCollection{},
-		useMultiset:  true,
-		diffMultiset: ecc.NewMultiset(ecc.S256()),
+		toAdd:    utxoCollection{},
+		toRemove: utxoCollection{},
 	}
 }
 
@@ -209,9 +196,8 @@ func NewUTXODiff() *UTXODiff {
 //    diffFrom results in the UTXO being added to toAdd
 func (d *UTXODiff) diffFrom(other *UTXODiff) (*UTXODiff, error) {
 	result := UTXODiff{
-		toAdd:       make(utxoCollection, len(d.toRemove)+len(other.toAdd)),
-		toRemove:    make(utxoCollection, len(d.toAdd)+len(other.toRemove)),
-		useMultiset: d.useMultiset,
+		toAdd:    make(utxoCollection, len(d.toRemove)+len(other.toAdd)),
+		toRemove: make(utxoCollection, len(d.toAdd)+len(other.toRemove)),
 	}
 
 	// Note that the following cases are not accounted for, as they are impossible
@@ -293,17 +279,12 @@ func (d *UTXODiff) diffFrom(other *UTXODiff) (*UTXODiff, error) {
 		}
 	}
 
-	if d.useMultiset {
-		// Create a new diffMultiset as the subtraction of the two diffs.
-		result.diffMultiset = other.diffMultiset.Subtract(d.diffMultiset)
-	}
-
 	return &result, nil
 }
 
-// WithDiffInPlace applies provided diff to this diff in-place, that would be the result if
+// withDiffInPlace applies provided diff to this diff in-place, that would be the result if
 // first d, and than diff were applied to the same base
-func (d *UTXODiff) WithDiffInPlace(diff *UTXODiff) error {
+func (d *UTXODiff) withDiffInPlace(diff *UTXODiff) error {
 	for outpoint, entryToRemove := range diff.toRemove {
 		if d.toAdd.containsWithBlueScore(outpoint, entryToRemove.blockBlueScore) {
 			// If already exists in toAdd with the same blueScore - remove from toAdd
@@ -313,7 +294,7 @@ func (d *UTXODiff) WithDiffInPlace(diff *UTXODiff) error {
 		if d.toRemove.contains(outpoint) {
 			// If already exists - this is an error
 			return ruleError(ErrWithDiff, fmt.Sprintf(
-				"WithDiffInPlace: outpoint %s both in d.toRemove and in diff.toRemove", outpoint))
+				"withDiffInPlace: outpoint %s both in d.toRemove and in diff.toRemove", outpoint))
 		}
 
 		// If not exists neither in toAdd nor in toRemove - add to toRemove
@@ -325,7 +306,7 @@ func (d *UTXODiff) WithDiffInPlace(diff *UTXODiff) error {
 			// If already exists in toRemove with the same blueScore - remove from toRemove
 			if d.toAdd.contains(outpoint) && !diff.toRemove.contains(outpoint) {
 				return ruleError(ErrWithDiff, fmt.Sprintf(
-					"WithDiffInPlace: outpoint %s both in d.toAdd and in diff.toAdd with no "+
+					"withDiffInPlace: outpoint %s both in d.toAdd and in diff.toAdd with no "+
 						"corresponding entry in diff.toRemove", outpoint))
 			}
 			d.toRemove.remove(outpoint)
@@ -336,129 +317,34 @@ func (d *UTXODiff) WithDiffInPlace(diff *UTXODiff) error {
 				!diff.toRemove.containsWithBlueScore(outpoint, existingEntry.blockBlueScore)) {
 			// If already exists - this is an error
 			return ruleError(ErrWithDiff, fmt.Sprintf(
-				"WithDiffInPlace: outpoint %s both in d.toAdd and in diff.toAdd", outpoint))
+				"withDiffInPlace: outpoint %s both in d.toAdd and in diff.toAdd", outpoint))
 		}
 
 		// If not exists neither in toAdd nor in toRemove, or exists in toRemove with different blueScore - add to toAdd
 		d.toAdd.add(outpoint, entryToAdd)
 	}
 
-	// Apply diff.diffMultiset to d.diffMultiset
-	if d.useMultiset {
-		d.diffMultiset = d.diffMultiset.Union(diff.diffMultiset)
-	}
-
 	return nil
 }
 
 // WithDiff applies provided diff to this diff, creating a new utxoDiff, that would be the result if
-// first d, and than diff were applied to the same base
-//
-// WithDiff follows a set of rules represented by the following 3 by 3 table:
-//
-//          |           | this      |           |
-// ---------+-----------+-----------+-----------+-----------
-//          |           | toAdd     | toRemove  | None
-// ---------+-----------+-----------+-----------+-----------
-// other    | toAdd     | X         | -         | toAdd
-// ---------+-----------+-----------+-----------+-----------
-//          | toRemove  | -         | X         | toRemove
-// ---------+-----------+-----------+-----------+-----------
-//          | None      | toAdd     | toRemove  | -
-//
-// Key:
-// -		Don't add anything to the result
-// X		Return an error
-// toAdd	Add the UTXO into the toAdd collection of the result
-// toRemove	Add the UTXO into the toRemove collection of the result
-//
-// Examples:
-// 1. This diff contains a UTXO in toAdd, and the other diff contains it in toRemove
-//    WithDiff results in nothing being added
-// 2. This diff contains a UTXO in toRemove, and the other diff does not contain it
-//    WithDiff results in the UTXO being added to toRemove
+// first d, and than diff were applied to some base
 func (d *UTXODiff) WithDiff(diff *UTXODiff) (*UTXODiff, error) {
-	result := UTXODiff{
-		toAdd:       make(utxoCollection, len(d.toAdd)+len(diff.toAdd)),
-		toRemove:    make(utxoCollection, len(d.toRemove)+len(diff.toRemove)),
-		useMultiset: d.useMultiset,
+	clone := d.clone()
+
+	err := clone.withDiffInPlace(diff)
+	if err != nil {
+		return nil, err
 	}
 
-	// All transactions in d.toAdd:
-	// If they are not in diff.toRemove - should be added in result.toAdd
-	// If they are in diff.toAdd - should throw an error
-	// Otherwise - should be ignored
-	for outpoint, utxoEntry := range d.toAdd {
-		if !diff.toRemove.containsWithBlueScore(outpoint, utxoEntry.blockBlueScore) {
-			result.toAdd.add(outpoint, utxoEntry)
-		}
-		if diffEntry, ok := diff.toAdd.get(outpoint); ok {
-			// An exception is made for entries with unequal blue scores
-			// as long as the appropriate entry exists in either d.toRemove
-			// or diff.toRemove.
-			// These are just "updates" to accepted blue score
-			if diffEntry.blockBlueScore != utxoEntry.blockBlueScore &&
-				diff.toRemove.containsWithBlueScore(outpoint, utxoEntry.blockBlueScore) {
-				continue
-			}
-			return nil, ruleError(ErrWithDiff, fmt.Sprintf("WithDiff: outpoint %s both in d.toAdd and in other.toAdd", outpoint))
-		}
-	}
-
-	// All transactions in d.toRemove:
-	// If they are not in diff.toAdd - should be added in result.toRemove
-	// If they are in diff.toRemove - should throw an error
-	// Otherwise - should be ignored
-	for outpoint, utxoEntry := range d.toRemove {
-		if !diff.toAdd.containsWithBlueScore(outpoint, utxoEntry.blockBlueScore) {
-			result.toRemove.add(outpoint, utxoEntry)
-		}
-		if diffEntry, ok := diff.toRemove.get(outpoint); ok {
-			// An exception is made for entries with unequal blue scores
-			// as long as the appropriate entry exists in either d.toAdd
-			// or diff.toAdd.
-			// These are just "updates" to accepted blue score
-			if diffEntry.blockBlueScore != utxoEntry.blockBlueScore &&
-				d.toAdd.containsWithBlueScore(outpoint, diffEntry.blockBlueScore) {
-				continue
-			}
-			return nil, ruleError(ErrWithDiff, "WithDiff: outpoint both in d.toRemove and in other.toRemove")
-		}
-	}
-
-	// All transactions in diff.toAdd:
-	// If they are not in d.toRemove - should be added in result.toAdd
-	for outpoint, utxoEntry := range diff.toAdd {
-		if !d.toRemove.containsWithBlueScore(outpoint, utxoEntry.blockBlueScore) {
-			result.toAdd.add(outpoint, utxoEntry)
-		}
-	}
-
-	// All transactions in diff.toRemove:
-	// If they are not in d.toAdd - should be added in result.toRemove
-	for outpoint, utxoEntry := range diff.toRemove {
-		if !d.toAdd.containsWithBlueScore(outpoint, utxoEntry.blockBlueScore) {
-			result.toRemove.add(outpoint, utxoEntry)
-		}
-	}
-
-	// Apply diff.diffMultiset to d.diffMultiset
-	if d.useMultiset {
-		result.diffMultiset = d.diffMultiset.Union(diff.diffMultiset)
-	}
-
-	return &result, nil
+	return clone, nil
 }
 
 // clone returns a clone of this utxoDiff
 func (d *UTXODiff) clone() *UTXODiff {
 	clone := &UTXODiff{
-		toAdd:       d.toAdd.clone(),
-		toRemove:    d.toRemove.clone(),
-		useMultiset: d.useMultiset,
-	}
-	if d.useMultiset {
-		clone.diffMultiset = d.diffMultiset.Clone()
+		toAdd:    d.toAdd.clone(),
+		toRemove: d.toRemove.clone(),
 	}
 	return clone
 }
@@ -475,14 +361,6 @@ func (d *UTXODiff) AddEntry(outpoint wire.Outpoint, entry *UTXOEntry) error {
 	} else {
 		d.toAdd.add(outpoint, entry)
 	}
-
-	if d.useMultiset {
-		newMs, err := addUTXOToMultiset(d.diffMultiset, entry, &outpoint)
-		if err != nil {
-			return err
-		}
-		d.diffMultiset = newMs
-	}
 	return nil
 }
 
@@ -498,21 +376,10 @@ func (d *UTXODiff) RemoveEntry(outpoint wire.Outpoint, entry *UTXOEntry) error {
 	} else {
 		d.toRemove.add(outpoint, entry)
 	}
-
-	if d.useMultiset {
-		newMs, err := removeUTXOFromMultiset(d.diffMultiset, entry, &outpoint)
-		if err != nil {
-			return err
-		}
-		d.diffMultiset = newMs
-	}
 	return nil
 }
 
 func (d UTXODiff) String() string {
-	if d.useMultiset {
-		return fmt.Sprintf("toAdd: %s; toRemove: %s, Multiset-Hash: %s", d.toAdd, d.toRemove, d.diffMultiset.Hash())
-	}
 	return fmt.Sprintf("toAdd: %s; toRemove: %s", d.toAdd, d.toRemove)
 }
 
@@ -537,8 +404,6 @@ type UTXOSet interface {
 	AddTx(tx *wire.MsgTx, blockBlueScore uint64) (ok bool, err error)
 	clone() UTXOSet
 	Get(outpoint wire.Outpoint) (*UTXOEntry, bool)
-	Multiset() *ecc.Multiset
-	WithTransactions(transactions []*wire.MsgTx, blockBlueScore uint64, ignoreDoubleSpends bool) (UTXOSet, error)
 }
 
 // diffFromTx is a common implementation for diffFromTx, that works
@@ -608,21 +473,19 @@ func diffFromAcceptedTx(u UTXOSet, tx *wire.MsgTx, acceptingBlueScore uint64) (*
 // FullUTXOSet represents a full list of transaction outputs and their values
 type FullUTXOSet struct {
 	utxoCollection
-	UTXOMultiset *ecc.Multiset
 }
 
 // NewFullUTXOSet creates a new utxoSet with full list of transaction outputs and their values
 func NewFullUTXOSet() *FullUTXOSet {
 	return &FullUTXOSet{
 		utxoCollection: utxoCollection{},
-		UTXOMultiset:   ecc.NewMultiset(ecc.S256()),
 	}
 }
 
 // newFullUTXOSetFromUTXOCollection converts a utxoCollection to a FullUTXOSet
 func newFullUTXOSetFromUTXOCollection(collection utxoCollection) (*FullUTXOSet, error) {
 	var err error
-	multiset := ecc.NewMultiset(ecc.S256())
+	multiset := secp256k1.NewMultiset()
 	for outpoint, utxoEntry := range collection {
 		multiset, err = addUTXOToMultiset(multiset, utxoEntry, &outpoint)
 		if err != nil {
@@ -631,7 +494,6 @@ func newFullUTXOSetFromUTXOCollection(collection utxoCollection) (*FullUTXOSet,
 	}
 	return &FullUTXOSet{
 		utxoCollection: collection,
-		UTXOMultiset:   multiset,
 	}, nil
 }
 
@@ -668,22 +530,14 @@ func (fus *FullUTXOSet) AddTx(tx *wire.MsgTx, blueScore uint64) (isAccepted bool
 		}
 
 		for _, txIn := range tx.TxIn {
-			outpoint := *wire.NewOutpoint(&txIn.PreviousOutpoint.TxID, txIn.PreviousOutpoint.Index)
-			err := fus.removeAndUpdateMultiset(outpoint)
-			if err != nil {
-				return false, err
-			}
+			fus.remove(txIn.PreviousOutpoint)
 		}
 	}
 
 	for i, txOut := range tx.TxOut {
 		outpoint := *wire.NewOutpoint(tx.TxID(), uint32(i))
 		entry := NewUTXOEntry(txOut, isCoinbase, blueScore)
-
-		err := fus.addAndUpdateMultiset(outpoint, entry)
-		if err != nil {
-			return false, err
-		}
+		fus.add(outpoint, entry)
 	}
 
 	return true, nil
@@ -712,7 +566,7 @@ func (fus *FullUTXOSet) diffFromAcceptedTx(tx *wire.MsgTx, acceptingBlueScore ui
 
 // clone returns a clone of this utxoSet
 func (fus *FullUTXOSet) clone() UTXOSet {
-	return &FullUTXOSet{utxoCollection: fus.utxoCollection.clone(), UTXOMultiset: fus.UTXOMultiset.Clone()}
+	return &FullUTXOSet{utxoCollection: fus.utxoCollection.clone()}
 }
 
 // Get returns the UTXOEntry associated with the given Outpoint, and a boolean indicating if such entry was found
@@ -721,55 +575,6 @@ func (fus *FullUTXOSet) Get(outpoint wire.Outpoint) (*UTXOEntry, bool) {
 	return utxoEntry, ok
 }
 
-// Multiset returns the ecmh-Multiset of this utxoSet
-func (fus *FullUTXOSet) Multiset() *ecc.Multiset {
-	return fus.UTXOMultiset
-}
-
-// addAndUpdateMultiset adds a UTXOEntry to this utxoSet and updates its multiset accordingly
-func (fus *FullUTXOSet) addAndUpdateMultiset(outpoint wire.Outpoint, entry *UTXOEntry) error {
-	fus.add(outpoint, entry)
-	newMs, err := addUTXOToMultiset(fus.UTXOMultiset, entry, &outpoint)
-	if err != nil {
-		return err
-	}
-	fus.UTXOMultiset = newMs
-	return nil
-}
-
-// removeAndUpdateMultiset removes a UTXOEntry from this utxoSet and updates its multiset accordingly
-func (fus *FullUTXOSet) removeAndUpdateMultiset(outpoint wire.Outpoint) error {
-	entry, ok := fus.Get(outpoint)
-	if !ok {
-		return errors.Errorf("Couldn't find outpoint %s", outpoint)
-	}
-	fus.remove(outpoint)
-	var err error
-	newMs, err := removeUTXOFromMultiset(fus.UTXOMultiset, entry, &outpoint)
-	if err != nil {
-		return err
-	}
-	fus.UTXOMultiset = newMs
-	return nil
-}
-
-// WithTransactions returns a new UTXO Set with the added transactions.
-//
-// This function MUST be called with the DAG lock held.
-func (fus *FullUTXOSet) WithTransactions(transactions []*wire.MsgTx, blockBlueScore uint64, ignoreDoubleSpends bool) (UTXOSet, error) {
-	diffSet := NewDiffUTXOSet(fus, NewUTXODiff())
-	for _, tx := range transactions {
-		isAccepted, err := diffSet.AddTx(tx, blockBlueScore)
-		if err != nil {
-			return nil, err
-		}
-		if !ignoreDoubleSpends && !isAccepted {
-			return nil, errors.Errorf("Transaction %s is not valid with the current UTXO set", tx.TxID())
-		}
-	}
-	return UTXOSet(diffSet), nil
-}
-
 // DiffUTXOSet represents a utxoSet with a base fullUTXOSet and a UTXODiff
 type DiffUTXOSet struct {
 	base     *FullUTXOSet
@@ -830,12 +635,11 @@ func (dus *DiffUTXOSet) AddTx(tx *wire.MsgTx, blockBlueScore uint64) (bool, erro
 func (dus *DiffUTXOSet) appendTx(tx *wire.MsgTx, blockBlueScore uint64, isCoinbase bool) error {
 	if !isCoinbase {
 		for _, txIn := range tx.TxIn {
-			outpoint := *wire.NewOutpoint(&txIn.PreviousOutpoint.TxID, txIn.PreviousOutpoint.Index)
-			entry, ok := dus.Get(outpoint)
+			entry, ok := dus.Get(txIn.PreviousOutpoint)
 			if !ok {
-				return errors.Errorf("Couldn't find entry for outpoint %s", outpoint)
+				return errors.Errorf("Couldn't find entry for outpoint %s", txIn.PreviousOutpoint)
 			}
-			err := dus.UTXODiff.RemoveEntry(outpoint, entry)
+			err := dus.UTXODiff.RemoveEntry(txIn.PreviousOutpoint, entry)
 			if err != nil {
 				return err
 			}
@@ -881,16 +685,7 @@ func (dus *DiffUTXOSet) meldToBase() error {
 	for outpoint, utxoEntry := range dus.UTXODiff.toAdd {
 		dus.base.add(outpoint, utxoEntry)
 	}
-
-	if dus.UTXODiff.useMultiset {
-		dus.base.UTXOMultiset = dus.base.UTXOMultiset.Union(dus.UTXODiff.diffMultiset)
-	}
-
-	if dus.UTXODiff.useMultiset {
-		dus.UTXODiff = NewUTXODiff()
-	} else {
-		dus.UTXODiff = NewUTXODiffWithoutMultiset()
-	}
+	dus.UTXODiff = NewUTXODiff()
 	return nil
 }
 
@@ -905,7 +700,7 @@ func (dus *DiffUTXOSet) diffFromAcceptedTx(tx *wire.MsgTx, acceptingBlueScore ui
 }
 
 func (dus *DiffUTXOSet) String() string {
-	return fmt.Sprintf("{Base: %s, To Add: %s, To Remove: %s, Multiset-Hash:%s}", dus.base, dus.UTXODiff.toAdd, dus.UTXODiff.toRemove, dus.Multiset().Hash())
+	return fmt.Sprintf("{Base: %s, To Add: %s, To Remove: %s}", dus.base, dus.UTXODiff.toAdd, dus.UTXODiff.toRemove)
 }
 
 // clone returns a clone of this UTXO Set
@@ -930,42 +725,3 @@ func (dus *DiffUTXOSet) Get(outpoint wire.Outpoint) (*UTXOEntry, bool) {
 	txOut, ok := dus.UTXODiff.toAdd.get(outpoint)
 	return txOut, ok
 }
-
-// Multiset returns the ecmh-Multiset of this utxoSet
-func (dus *DiffUTXOSet) Multiset() *ecc.Multiset {
-	return dus.base.UTXOMultiset.Union(dus.UTXODiff.diffMultiset)
-}
-
-// WithTransactions returns a new UTXO Set with the added transactions.
-//
-// If dus.UTXODiff.useMultiset is true, this function MUST be
-// called with the DAG lock held.
-func (dus *DiffUTXOSet) WithTransactions(transactions []*wire.MsgTx, blockBlueScore uint64, ignoreDoubleSpends bool) (UTXOSet, error) {
-	diffSet := NewDiffUTXOSet(dus.base, dus.UTXODiff.clone())
-	for _, tx := range transactions {
-		isAccepted, err := diffSet.AddTx(tx, blockBlueScore)
-		if err != nil {
-			return nil, err
-		}
-		if !ignoreDoubleSpends && !isAccepted {
-			return nil, errors.Errorf("Transaction %s is not valid with the current UTXO set", tx.TxID())
-		}
-	}
-	return UTXOSet(diffSet), nil
-}
-
-func addUTXOToMultiset(ms *ecc.Multiset, entry *UTXOEntry, outpoint *wire.Outpoint) (*ecc.Multiset, error) {
-	utxoMS, err := utxoMultiset(entry, outpoint)
-	if err != nil {
-		return nil, err
-	}
-	return ms.Union(utxoMS), nil
-}
-
-func removeUTXOFromMultiset(ms *ecc.Multiset, entry *UTXOEntry, outpoint *wire.Outpoint) (*ecc.Multiset, error) {
-	utxoMS, err := utxoMultiset(entry, outpoint)
-	if err != nil {
-		return nil, err
-	}
-	return ms.Subtract(utxoMS), nil
-}

blockdag/utxoset_test.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/kaspanet/kaspad/util/subnetworkid"
 
-	"github.com/kaspanet/kaspad/ecc"
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
 )
@@ -80,49 +79,40 @@ func TestUTXODiff(t *testing.T) {
 	utxoEntry0 := NewUTXOEntry(&wire.TxOut{ScriptPubKey: []byte{}, Value: 10}, true, 0)
 	utxoEntry1 := NewUTXOEntry(&wire.TxOut{ScriptPubKey: []byte{}, Value: 20}, false, 1)
 
-	for i := 0; i < 2; i++ {
-		withMultiset := i == 0
-		// Test utxoDiff creation
-		var diff *UTXODiff
-		if withMultiset {
-			diff = NewUTXODiff()
-		} else {
-			diff = NewUTXODiffWithoutMultiset()
-		}
-		if len(diff.toAdd) != 0 || len(diff.toRemove) != 0 {
-			t.Errorf("new diff is not empty")
-		}
+	// Test utxoDiff creation
 
-		err := diff.AddEntry(outpoint0, utxoEntry0)
-		if err != nil {
-			t.Fatalf("error adding entry to utxo diff: %s", err)
-		}
+	diff := NewUTXODiff()
 
-		err = diff.RemoveEntry(outpoint1, utxoEntry1)
-		if err != nil {
-			t.Fatalf("error adding entry to utxo diff: %s", err)
-		}
+	if len(diff.toAdd) != 0 || len(diff.toRemove) != 0 {
+		t.Errorf("new diff is not empty")
+	}
 
-		// Test utxoDiff cloning
-		clonedDiff := diff.clone()
-		if clonedDiff == diff {
-			t.Errorf("cloned diff is reference-equal to the original")
-		}
-		if !reflect.DeepEqual(clonedDiff, diff) {
-			t.Errorf("cloned diff not equal to the original"+
-				"Original: \"%v\", cloned: \"%v\".", diff, clonedDiff)
-		}
+	err := diff.AddEntry(outpoint0, utxoEntry0)
+	if err != nil {
+		t.Fatalf("error adding entry to utxo diff: %s", err)
+	}
 
-		// Test utxoDiff string representation
-		expectedDiffString := "toAdd: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ]; toRemove: [ (1111111111111111111111111111111111111111111111111111111111111111, 0) => 20, blueScore: 1 ]"
-		if withMultiset {
-			expectedDiffString = "toAdd: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ]; toRemove: [ (1111111111111111111111111111111111111111111111111111111111111111, 0) => 20, blueScore: 1 ], Multiset-Hash: 7cb61e48005b0c817211d04589d719bff87d86a6a6ce2454515f57265382ded7"
-		}
-		diffString := clonedDiff.String()
-		if diffString != expectedDiffString {
-			t.Errorf("unexpected diff string. "+
-				"Expected: \"%s\", got: \"%s\".", expectedDiffString, diffString)
-		}
+	err = diff.RemoveEntry(outpoint1, utxoEntry1)
+	if err != nil {
+		t.Fatalf("error adding entry to utxo diff: %s", err)
+	}
+
+	// Test utxoDiff cloning
+	clonedDiff := diff.clone()
+	if clonedDiff == diff {
+		t.Errorf("cloned diff is reference-equal to the original")
+	}
+	if !reflect.DeepEqual(clonedDiff, diff) {
+		t.Errorf("cloned diff not equal to the original"+
+			"Original: \"%v\", cloned: \"%v\".", diff, clonedDiff)
+	}
+
+	// Test utxoDiff string representation
+	expectedDiffString := "toAdd: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ]; toRemove: [ (1111111111111111111111111111111111111111111111111111111111111111, 0) => 20, blueScore: 1 ]"
+	diffString := clonedDiff.String()
+	if diffString != expectedDiffString {
+		t.Errorf("unexpected diff string. "+
+			"Expected: \"%s\", got: \"%s\".", expectedDiffString, diffString)
 	}
 }
 
@@ -137,7 +127,7 @@ func TestUTXODiffRules(t *testing.T) {
 	// For each of the following test cases, we will:
 	// this.diffFrom(other) and compare it to expectedDiffFromResult
 	// this.WithDiff(other) and compare it to expectedWithDiffResult
-	// this.WithDiffInPlace(other) and compare it to expectedWithDiffResult
+	// this.withDiffInPlace(other) and compare it to expectedWithDiffResult
 	//
 	// Note: an expected nil result means that we expect the respective operation to fail
 	// See the following spreadsheet for a summary of all test-cases:
@@ -542,157 +532,101 @@ func TestUTXODiffRules(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		this := addMultisetToDiff(t, test.this)
-		other := addMultisetToDiff(t, test.other)
-		expectedDiffFromResult := addMultisetToDiff(t, test.expectedDiffFromResult)
-		expectedWithDiffResult := addMultisetToDiff(t, test.expectedWithDiffResult)
-
-		// diffFrom from this to other
-		diffResult, err := this.diffFrom(other)
+		// diffFrom from test.this to test.other
+		diffResult, err := test.this.diffFrom(test.other)
 
 		// Test whether diffFrom returned an error
 		isDiffFromOk := err == nil
-		expectedIsDiffFromOk := expectedDiffFromResult != nil
+		expectedIsDiffFromOk := test.expectedDiffFromResult != nil
 		if isDiffFromOk != expectedIsDiffFromOk {
 			t.Errorf("unexpected diffFrom error in test \"%s\". "+
 				"Expected: \"%t\", got: \"%t\".", test.name, expectedIsDiffFromOk, isDiffFromOk)
 		}
 
 		// If not error, test the diffFrom result
-		if isDiffFromOk && !expectedDiffFromResult.equal(diffResult) {
+		if isDiffFromOk && !test.expectedDiffFromResult.equal(diffResult) {
 			t.Errorf("unexpected diffFrom result in test \"%s\". "+
-				"Expected: \"%v\", got: \"%v\".", test.name, expectedDiffFromResult, diffResult)
+				"Expected: \"%v\", got: \"%v\".", test.name, test.expectedDiffFromResult, diffResult)
 		}
 
-		// Make sure that WithDiff after diffFrom results in the original other
+		// Make sure that WithDiff after diffFrom results in the original test.other
 		if isDiffFromOk {
-			otherResult, err := this.WithDiff(diffResult)
+			otherResult, err := test.this.WithDiff(diffResult)
 			if err != nil {
 				t.Errorf("WithDiff unexpectedly failed in test \"%s\": %s", test.name, err)
 			}
-			if !other.equal(otherResult) {
+			if !test.other.equal(otherResult) {
 				t.Errorf("unexpected WithDiff result in test \"%s\". "+
-					"Expected: \"%v\", got: \"%v\".", test.name, other, otherResult)
+					"Expected: \"%v\", got: \"%v\".", test.name, test.other, otherResult)
 			}
 		}
 
-		// WithDiff from this to other
-		withDiffResult, err := this.WithDiff(other)
+		// WithDiff from test.this to test.other
+		withDiffResult, err := test.this.WithDiff(test.other)
 
 		// Test whether WithDiff returned an error
 		isWithDiffOk := err == nil
-		expectedIsWithDiffOk := expectedWithDiffResult != nil
+		expectedIsWithDiffOk := test.expectedWithDiffResult != nil
 		if isWithDiffOk != expectedIsWithDiffOk {
 			t.Errorf("unexpected WithDiff error in test \"%s\". "+
 				"Expected: \"%t\", got: \"%t\".", test.name, expectedIsWithDiffOk, isWithDiffOk)
 		}
 
 		// If not error, test the WithDiff result
-		if isWithDiffOk && !withDiffResult.equal(expectedWithDiffResult) {
+		if isWithDiffOk && !withDiffResult.equal(test.expectedWithDiffResult) {
 			t.Errorf("unexpected WithDiff result in test \"%s\". "+
-				"Expected: \"%v\", got: \"%v\".", test.name, expectedWithDiffResult, withDiffResult)
+				"Expected: \"%v\", got: \"%v\".", test.name, test.expectedWithDiffResult, withDiffResult)
 		}
 
-		// Repeat WithDiff check this time using WithDiffInPlace
-		thisClone := this.clone()
-		err = thisClone.WithDiffInPlace(other)
+		// Repeat WithDiff check test.this time using withDiffInPlace
+		thisClone := test.this.clone()
+		err = thisClone.withDiffInPlace(test.other)
 
-		// Test whether WithDiffInPlace returned an error
+		// Test whether withDiffInPlace returned an error
 		isWithDiffInPlaceOk := err == nil
-		expectedIsWithDiffInPlaceOk := expectedWithDiffResult != nil
+		expectedIsWithDiffInPlaceOk := test.expectedWithDiffResult != nil
 		if isWithDiffInPlaceOk != expectedIsWithDiffInPlaceOk {
-			t.Errorf("unexpected WithDiffInPlace error in test \"%s\". "+
+			t.Errorf("unexpected withDiffInPlace error in test \"%s\". "+
 				"Expected: \"%t\", got: \"%t\".", test.name, expectedIsWithDiffInPlaceOk, isWithDiffInPlaceOk)
 		}
 
-		// If not error, test the WithDiffInPlace result
-		if isWithDiffInPlaceOk && !thisClone.equal(expectedWithDiffResult) {
-			t.Errorf("unexpected WithDiffInPlace result in test \"%s\". "+
-				"Expected: \"%v\", got: \"%v\".", test.name, expectedWithDiffResult, thisClone)
+		// If not error, test the withDiffInPlace result
+		if isWithDiffInPlaceOk && !thisClone.equal(test.expectedWithDiffResult) {
+			t.Errorf("unexpected withDiffInPlace result in test \"%s\". "+
+				"Expected: \"%v\", got: \"%v\".", test.name, test.expectedWithDiffResult, thisClone)
 		}
 
-		// Make sure that diffFrom after WithDiff results in the original other
+		// Make sure that diffFrom after WithDiff results in the original test.other
 		if isWithDiffOk {
-			otherResult, err := this.diffFrom(withDiffResult)
+			otherResult, err := test.this.diffFrom(withDiffResult)
 			if err != nil {
 				t.Errorf("diffFrom unexpectedly failed in test \"%s\": %s", test.name, err)
 			}
-			if !other.equal(otherResult) {
+			if !test.other.equal(otherResult) {
 				t.Errorf("unexpected diffFrom result in test \"%s\". "+
-					"Expected: \"%v\", got: \"%v\".", test.name, other, otherResult)
+					"Expected: \"%v\", got: \"%v\".", test.name, test.other, otherResult)
 			}
 		}
 	}
 }
 
-func areMultisetsEqual(a *ecc.Multiset, b *ecc.Multiset) bool {
-	aX, aY := a.Point()
-	bX, bY := b.Point()
-	return aX.Cmp(bX) == 0 && aY.Cmp(bY) == 0
-}
-
 func (d *UTXODiff) equal(other *UTXODiff) bool {
 	if d == nil || other == nil {
 		return d == other
 	}
 
 	return reflect.DeepEqual(d.toAdd, other.toAdd) &&
-		reflect.DeepEqual(d.toRemove, other.toRemove) &&
-		areMultisetsEqual(d.diffMultiset, other.diffMultiset)
+		reflect.DeepEqual(d.toRemove, other.toRemove)
 }
 
 func (fus *FullUTXOSet) equal(other *FullUTXOSet) bool {
-	return reflect.DeepEqual(fus.utxoCollection, other.utxoCollection) &&
-		areMultisetsEqual(fus.UTXOMultiset, other.UTXOMultiset)
+	return reflect.DeepEqual(fus.utxoCollection, other.utxoCollection)
 }
 
 func (dus *DiffUTXOSet) equal(other *DiffUTXOSet) bool {
 	return dus.base.equal(other.base) && dus.UTXODiff.equal(other.UTXODiff)
 }
 
-func addMultisetToDiff(t *testing.T, diff *UTXODiff) *UTXODiff {
-	if diff == nil {
-		return nil
-	}
-	diffWithMs := NewUTXODiff()
-	for outpoint, entry := range diff.toAdd {
-		err := diffWithMs.AddEntry(outpoint, entry)
-		if err != nil {
-			t.Fatalf("Error with diffWithMs.AddEntry: %s", err)
-		}
-	}
-	for outpoint, entry := range diff.toRemove {
-		err := diffWithMs.RemoveEntry(outpoint, entry)
-		if err != nil {
-			t.Fatalf("Error with diffWithMs.removeEntry: %s", err)
-		}
-	}
-	return diffWithMs
-}
-
-func addMultisetToFullUTXOSet(t *testing.T, fus *FullUTXOSet) *FullUTXOSet {
-	if fus == nil {
-		return nil
-	}
-	fusWithMs := NewFullUTXOSet()
-	for outpoint, entry := range fus.utxoCollection {
-		err := fusWithMs.addAndUpdateMultiset(outpoint, entry)
-		if err != nil {
-			t.Fatalf("Error with diffWithMs.AddEntry: %s", err)
-		}
-	}
-	return fusWithMs
-}
-
-func addMultisetToDiffUTXOSet(t *testing.T, diffSet *DiffUTXOSet) *DiffUTXOSet {
-	if diffSet == nil {
-		return nil
-	}
-	diffWithMs := addMultisetToDiff(t, diffSet.UTXODiff)
-	baseWithMs := addMultisetToFullUTXOSet(t, diffSet.base)
-	return NewDiffUTXOSet(baseWithMs, diffWithMs)
-}
-
 // TestFullUTXOSet makes sure that fullUTXOSet is working as expected.
 func TestFullUTXOSet(t *testing.T) {
 	txID0, _ := daghash.NewTxIDFromStr("0000000000000000000000000000000000000000000000000000000000000000")
@@ -703,10 +637,10 @@ func TestFullUTXOSet(t *testing.T) {
 	txOut1 := &wire.TxOut{ScriptPubKey: []byte{}, Value: 20}
 	utxoEntry0 := NewUTXOEntry(txOut0, true, 0)
 	utxoEntry1 := NewUTXOEntry(txOut1, false, 1)
-	diff := addMultisetToDiff(t, &UTXODiff{
+	diff := &UTXODiff{
 		toAdd:    utxoCollection{outpoint0: utxoEntry0},
 		toRemove: utxoCollection{outpoint1: utxoEntry1},
-	})
+	}
 
 	// Test fullUTXOSet creation
 	emptySet := NewFullUTXOSet()
@@ -735,7 +669,7 @@ func TestFullUTXOSet(t *testing.T) {
 	} else if isAccepted {
 		t.Errorf("addTx unexpectedly succeeded")
 	}
-	emptySet = addMultisetToFullUTXOSet(t, &FullUTXOSet{utxoCollection: utxoCollection{outpoint0: utxoEntry0}})
+	emptySet = &FullUTXOSet{utxoCollection: utxoCollection{outpoint0: utxoEntry0}}
 	if isAccepted, err := emptySet.AddTx(transaction0, 0); err != nil {
 		t.Errorf("addTx unexpectedly failed. Error: %s", err)
 	} else if !isAccepted {
@@ -767,10 +701,10 @@ func TestDiffUTXOSet(t *testing.T) {
 	txOut1 := &wire.TxOut{ScriptPubKey: []byte{}, Value: 20}
 	utxoEntry0 := NewUTXOEntry(txOut0, true, 0)
 	utxoEntry1 := NewUTXOEntry(txOut1, false, 1)
-	diff := addMultisetToDiff(t, &UTXODiff{
+	diff := &UTXODiff{
 		toAdd:    utxoCollection{outpoint0: utxoEntry0},
 		toRemove: utxoCollection{outpoint1: utxoEntry1},
-	})
+	}
 
 	// Test diffUTXOSet creation
 	emptySet := NewDiffUTXOSet(NewFullUTXOSet(), NewUTXODiff())
@@ -828,7 +762,7 @@ func TestDiffUTXOSet(t *testing.T) {
 					toRemove: utxoCollection{},
 				},
 			},
-			expectedString:     "{Base: [  ], To Add: [  ], To Remove: [  ], Multiset-Hash:0000000000000000000000000000000000000000000000000000000000000000}",
+			expectedString:     "{Base: [  ], To Add: [  ], To Remove: [  ]}",
 			expectedCollection: utxoCollection{},
 		},
 		{
@@ -847,7 +781,7 @@ func TestDiffUTXOSet(t *testing.T) {
 					toRemove: utxoCollection{},
 				},
 			},
-			expectedString:     "{Base: [  ], To Add: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ], To Remove: [  ], Multiset-Hash:da4768bd0359c3426268d6707c1fc17a68c45ef1ea734331b07568418234487f}",
+			expectedString:     "{Base: [  ], To Add: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ], To Remove: [  ]}",
 			expectedCollection: utxoCollection{outpoint0: utxoEntry0},
 		},
 		{
@@ -860,7 +794,7 @@ func TestDiffUTXOSet(t *testing.T) {
 				},
 			},
 			expectedMeldSet:         nil,
-			expectedString:          "{Base: [  ], To Add: [  ], To Remove: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ], Multiset-Hash:046242cb1bb1e6d3fd91d0f181e1b2d4a597ac57fa2584fc3c2eb0e0f46c9369}",
+			expectedString:          "{Base: [  ], To Add: [  ], To Remove: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ]}",
 			expectedCollection:      utxoCollection{},
 			expectedMeldToBaseError: "Couldn't remove outpoint 0000000000000000000000000000000000000000000000000000000000000000:0 because it doesn't exist in the DiffUTXOSet base",
 		},
@@ -885,7 +819,7 @@ func TestDiffUTXOSet(t *testing.T) {
 					toRemove: utxoCollection{},
 				},
 			},
-			expectedString: "{Base: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ], To Add: [ (1111111111111111111111111111111111111111111111111111111111111111, 0) => 20, blueScore: 1 ], To Remove: [  ], Multiset-Hash:556cc61fd4d7e74d7807ca2298c5320375a6a20310a18920e54667220924baff}",
+			expectedString: "{Base: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ], To Add: [ (1111111111111111111111111111111111111111111111111111111111111111, 0) => 20, blueScore: 1 ], To Remove: [  ]}",
 			expectedCollection: utxoCollection{
 				outpoint0: utxoEntry0,
 				outpoint1: utxoEntry1,
@@ -909,24 +843,21 @@ func TestDiffUTXOSet(t *testing.T) {
 					toRemove: utxoCollection{},
 				},
 			},
-			expectedString:     "{Base: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ], To Add: [  ], To Remove: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ], Multiset-Hash:0000000000000000000000000000000000000000000000000000000000000000}",
+			expectedString:     "{Base: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ], To Add: [  ], To Remove: [ (0000000000000000000000000000000000000000000000000000000000000000, 0) => 10, blueScore: 0 ]}",
 			expectedCollection: utxoCollection{},
 		},
 	}
 
 	for _, test := range tests {
-		diffSet := addMultisetToDiffUTXOSet(t, test.diffSet)
-		expectedMeldSet := addMultisetToDiffUTXOSet(t, test.expectedMeldSet)
-
 		// Test string representation
-		setString := diffSet.String()
+		setString := test.diffSet.String()
 		if setString != test.expectedString {
 			t.Errorf("unexpected string in test \"%s\". "+
 				"Expected: \"%s\", got: \"%s\".", test.name, test.expectedString, setString)
 		}
 
 		// Test meldToBase
-		meldSet := diffSet.clone().(*DiffUTXOSet)
+		meldSet := test.diffSet.clone().(*DiffUTXOSet)
 		err := meldSet.meldToBase()
 		errString := ""
 		if err != nil {
@@ -938,27 +869,27 @@ func TestDiffUTXOSet(t *testing.T) {
 		if err != nil {
 			continue
 		}
-		if !meldSet.equal(expectedMeldSet) {
+		if !meldSet.equal(test.expectedMeldSet) {
 			t.Errorf("unexpected melded set in test \"%s\". "+
-				"Expected: \"%v\", got: \"%v\".", test.name, expectedMeldSet, meldSet)
+				"Expected: \"%v\", got: \"%v\".", test.name, test.expectedMeldSet, meldSet)
 		}
 
 		// Test collection
-		setCollection, err := diffSet.collection()
+		setCollection, err := test.diffSet.collection()
 		if err != nil {
-			t.Errorf("Error getting diffSet collection: %s", err)
+			t.Errorf("Error getting test.diffSet collection: %s", err)
 		} else if !reflect.DeepEqual(setCollection, test.expectedCollection) {
 			t.Errorf("unexpected set collection in test \"%s\". "+
 				"Expected: \"%v\", got: \"%v\".", test.name, test.expectedCollection, setCollection)
 		}
 
 		// Test cloning
-		clonedSet := diffSet.clone().(*DiffUTXOSet)
-		if !reflect.DeepEqual(clonedSet, diffSet) {
+		clonedSet := test.diffSet.clone().(*DiffUTXOSet)
+		if !reflect.DeepEqual(clonedSet, test.diffSet) {
 			t.Errorf("unexpected set clone in test \"%s\". "+
-				"Expected: \"%v\", got: \"%v\".", test.name, diffSet, clonedSet)
+				"Expected: \"%v\", got: \"%v\".", test.name, test.diffSet, clonedSet)
 		}
-		if clonedSet == diffSet {
+		if clonedSet == test.diffSet {
 			t.Errorf("cloned set is reference-equal to the original")
 		}
 	}
@@ -1159,10 +1090,7 @@ func TestDiffUTXOSet_addTx(t *testing.T) {
 
 testLoop:
 	for _, test := range tests {
-		startSet := addMultisetToDiffUTXOSet(t, test.startSet)
-		expectedSet := addMultisetToDiffUTXOSet(t, test.expectedSet)
-
-		diffSet := startSet.clone()
+		diffSet := test.startSet.clone()
 
 		// Apply all transactions to diffSet, in order, with the initial block height startHeight
 		for i, transaction := range test.toAdd {
@@ -1174,18 +1102,18 @@ testLoop:
 			}
 		}
 
-		// Make sure that the result diffSet equals to the expectedSet
-		if !diffSet.(*DiffUTXOSet).equal(expectedSet) {
+		// Make sure that the result diffSet equals to test.expectedSet
+		if !diffSet.(*DiffUTXOSet).equal(test.expectedSet) {
 			t.Errorf("unexpected diffSet in test \"%s\". "+
-				"Expected: \"%v\", got: \"%v\".", test.name, expectedSet, diffSet)
+				"Expected: \"%v\", got: \"%v\".", test.name, test.expectedSet, diffSet)
 		}
 	}
 }
 
 func TestDiffFromTx(t *testing.T) {
-	fus := addMultisetToFullUTXOSet(t, &FullUTXOSet{
+	fus := &FullUTXOSet{
 		utxoCollection: utxoCollection{},
-	})
+	}
 
 	txID0, _ := daghash.NewTxIDFromStr("0000000000000000000000000000000000000000000000000000000000000000")
 	txIn0 := &wire.TxIn{SignatureScript: []byte{}, PreviousOutpoint: wire.Outpoint{TxID: *txID0, Index: math.MaxUint32}, Sequence: 0}
@@ -1241,10 +1169,10 @@ func TestDiffFromTx(t *testing.T) {
 	}
 
 	//Test that we get an error if the outpoint is inside diffUTXOSet's toRemove
-	diff2 := addMultisetToDiff(t, &UTXODiff{
+	diff2 := &UTXODiff{
 		toAdd:    utxoCollection{},
 		toRemove: utxoCollection{},
-	})
+	}
 	dus := NewDiffUTXOSet(fus, diff2)
 	if isAccepted, err := dus.AddTx(tx, 2); err != nil {
 		t.Fatalf("AddTx unexpectedly failed. Error: %s", err)
@@ -1321,7 +1249,6 @@ func TestUTXOSetAddEntry(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		expectedUTXODiff := addMultisetToDiff(t, test.expectedUTXODiff)
 		err := utxoDiff.AddEntry(*test.outpointToAdd, test.utxoEntryToAdd)
 		errString := ""
 		if err != nil {
@@ -1330,9 +1257,9 @@ func TestUTXOSetAddEntry(t *testing.T) {
 		if errString != test.expectedError {
 			t.Fatalf("utxoDiff.AddEntry: unexpected err in test \"%s\". Expected: %s but got: %s", test.name, test.expectedError, err)
 		}
-		if err == nil && !utxoDiff.equal(expectedUTXODiff) {
+		if err == nil && !utxoDiff.equal(test.expectedUTXODiff) {
 			t.Fatalf("utxoDiff.AddEntry: unexpected utxoDiff in test \"%s\". "+
-				"Expected: %v, got: %v", test.name, expectedUTXODiff, utxoDiff)
+				"Expected: %v, got: %v", test.name, test.expectedUTXODiff, utxoDiff)
 		}
 	}
 }

blockdag/validate.go

@@ -435,7 +435,7 @@ func (dag *BlockDAG) checkBlockHeaderSanity(header *wire.BlockHeader, flags Beha
 	// the duration of time that should be waited before the block becomes valid.
 	// This check needs to be last as it does not return an error but rather marks the
 	// header as delayed (and valid).
-	maxTimestamp := dag.AdjustedTime().Add(time.Second *
+	maxTimestamp := dag.Now().Add(time.Second *
 		time.Duration(int64(dag.TimestampDeviationTolerance)*dag.targetTimePerBlock))
 	if header.Timestamp.After(maxTimestamp) {
 		return header.Timestamp.Sub(maxTimestamp), nil

blockdag/validate_test.go

@@ -69,7 +69,7 @@ func TestSequenceLocksActive(t *testing.T) {
 // ensure it fails.
 func TestCheckConnectBlockTemplate(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("checkconnectblocktemplate", Config{
+	dag, teardownFunc, err := DAGSetup("checkconnectblocktemplate", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
@@ -161,7 +161,7 @@ func TestCheckConnectBlockTemplate(t *testing.T) {
 // as expected.
 func TestCheckBlockSanity(t *testing.T) {
 	// Create a new database and dag instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("TestCheckBlockSanity", Config{
+	dag, teardownFunc, err := DAGSetup("TestCheckBlockSanity", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {
@@ -169,6 +169,7 @@ func TestCheckBlockSanity(t *testing.T) {
 		return
 	}
 	defer teardownFunc()
+	dag.timeSource = newFakeTimeSource(time.Now())
 
 	block := util.NewBlock(&Block100000)
 	if len(block.Transactions()) < 3 {
@@ -191,7 +192,8 @@ func TestCheckBlockSanity(t *testing.T) {
 	if !errors.As(err, &ruleErr) {
 		t.Errorf("CheckBlockSanity: wrong error returned, expect RuleError, got %T", err)
 	} else if ruleErr.ErrorCode != ErrTransactionsNotSorted {
-		t.Errorf("CheckBlockSanity: wrong error returned, expect ErrTransactionsNotSorted, got %v, err %s", ruleErr.ErrorCode, err)
+		t.Errorf("CheckBlockSanity: wrong error returned, expect ErrTransactionsNotSorted, got"+
+			" %v, err %s", ruleErr.ErrorCode, err)
 	}
 	if delay != 0 {
 		t.Errorf("CheckBlockSanity: unexpected return %s delay", delay)
@@ -492,8 +494,8 @@ func TestCheckBlockSanity(t *testing.T) {
 
 	blockInTheFuture := Block100000
 	expectedDelay := 10 * time.Second
-	now := time.Unix(time.Now().Unix(), 0)
-	blockInTheFuture.Header.Timestamp = now.Add(time.Duration(dag.TimestampDeviationTolerance)*time.Second + expectedDelay)
+	deviationTolerance := time.Duration(dag.TimestampDeviationTolerance*uint64(dag.targetTimePerBlock)) * time.Second
+	blockInTheFuture.Header.Timestamp = dag.Now().Add(deviationTolerance + expectedDelay)
 	delay, err = dag.checkBlockSanity(util.NewBlock(&blockInTheFuture), BFNoPoWCheck)
 	if err != nil {
 		t.Errorf("CheckBlockSanity: %v", err)
@@ -559,7 +561,7 @@ func TestPastMedianTime(t *testing.T) {
 
 func TestValidateParents(t *testing.T) {
 	// Create a new database and dag instance to run tests against.
-	dag, teardownFunc, err := DAGSetup("TestCheckBlockSanity", Config{
+	dag, teardownFunc, err := DAGSetup("TestCheckBlockSanity", true, Config{
 		DAGParams: &dagconfig.SimnetParams,
 	})
 	if err != nil {

blockdag/virtualblock_test.go

@@ -35,7 +35,7 @@ func TestVirtualBlock(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
 	params := dagconfig.SimnetParams
 	params.K = 1
-	dag, teardownFunc, err := DAGSetup("TestVirtualBlock", Config{
+	dag, teardownFunc, err := DAGSetup("TestVirtualBlock", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -134,7 +134,7 @@ func TestSelectedPath(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
 	params := dagconfig.SimnetParams
 	params.K = 1
-	dag, teardownFunc, err := DAGSetup("TestSelectedPath", Config{
+	dag, teardownFunc, err := DAGSetup("TestSelectedPath", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {
@@ -222,7 +222,7 @@ func TestChainUpdates(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
 	params := dagconfig.SimnetParams
 	params.K = 1
-	dag, teardownFunc, err := DAGSetup("TestChainUpdates", Config{
+	dag, teardownFunc, err := DAGSetup("TestChainUpdates", true, Config{
 		DAGParams: &params,
 	})
 	if err != nil {

cmd/addblock/addblock.go

@@ -5,12 +5,9 @@
 package main
 
 import (
-	"github.com/pkg/errors"
 	"os"
-	"path/filepath"
 	"runtime"
 
-	"github.com/kaspanet/kaspad/database"
 	"github.com/kaspanet/kaspad/limits"
 	"github.com/kaspanet/kaspad/logs"
 	"github.com/kaspanet/kaspad/util/panics"
@@ -27,39 +24,6 @@ var (
 	spawn func(func())
 )
 
-// loadBlockDB opens the block database and returns a handle to it.
-func loadBlockDB() (database.DB, error) {
-	// The database name is based on the database type.
-	dbName := blockDBNamePrefix + "_" + cfg.DBType
-	dbPath := filepath.Join(cfg.DataDir, dbName)
-
-	log.Infof("Loading block database from '%s'", dbPath)
-	db, err := database.Open(cfg.DBType, dbPath, ActiveConfig().NetParams().Net)
-	if err != nil {
-		// Return the error if it's not because the database doesn't
-		// exist.
-		var dbErr database.Error
-		if ok := errors.As(err, &dbErr); !ok || dbErr.ErrorCode !=
-			database.ErrDbDoesNotExist {
-
-			return nil, err
-		}
-
-		// Create the db if it does not exist.
-		err = os.MkdirAll(cfg.DataDir, 0700)
-		if err != nil {
-			return nil, err
-		}
-		db, err = database.Create(cfg.DBType, dbPath, ActiveConfig().NetParams().Net)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	log.Info("Block database loaded")
-	return db, nil
-}
-
 // realMain is the real main function for the utility. It is necessary to work
 // around the fact that deferred functions do not run when os.Exit() is called.
 func realMain() error {
@@ -76,14 +40,6 @@ func realMain() error {
 	log = backendLogger.Logger("MAIN")
 	spawn = panics.GoroutineWrapperFunc(log)
 
-	// Load the block database.
-	db, err := loadBlockDB()
-	if err != nil {
-		log.Errorf("Failed to load database: %s", err)
-		return err
-	}
-	defer db.Close()
-
 	fi, err := os.Open(cfg.InFile)
 	if err != nil {
 		log.Errorf("Failed to open file %s: %s", cfg.InFile, err)
@@ -94,7 +50,7 @@ func realMain() error {
 	// Create a block importer for the database and input file and start it.
 	// The done channel returned from start will contain an error if
 	// anything went wrong.
-	importer, err := newBlockImporter(db, fi)
+	importer, err := newBlockImporter(fi)
 	if err != nil {
 		log.Errorf("Failed create block importer: %s", err)
 		return err

cmd/addblock/config.go

@@ -6,20 +6,15 @@ package main
 
 import (
 	"fmt"
+	flags "github.com/jessevdk/go-flags"
 	"github.com/kaspanet/kaspad/config"
+	"github.com/kaspanet/kaspad/util"
 	"github.com/pkg/errors"
 	"os"
 	"path/filepath"
-	"strings"
-
-	flags "github.com/jessevdk/go-flags"
-	"github.com/kaspanet/kaspad/database"
-	_ "github.com/kaspanet/kaspad/database/ffldb"
-	"github.com/kaspanet/kaspad/util"
 )
 
 const (
-	defaultDBType   = "ffldb"
 	defaultDataFile = "bootstrap.dat"
 	defaultProgress = 10
 )
@@ -27,7 +22,6 @@ const (
 var (
 	kaspadHomeDir  = util.AppDataDir("kaspad", false)
 	defaultDataDir = filepath.Join(kaspadHomeDir, "data")
-	knownDbTypes   = database.SupportedDrivers()
 	activeConfig   *ConfigFlags
 )
 
@@ -41,7 +35,6 @@ func ActiveConfig() *ConfigFlags {
 // See loadConfig for details on the configuration load process.
 type ConfigFlags struct {
 	DataDir         string `short:"b" long:"datadir" description:"Location of the kaspad data directory"`
-	DBType          string `long:"dbtype" description:"Database backend to use for the Block DAG"`
 	InFile          string `short:"i" long:"infile" description:"File containing the block(s)"`
 	Progress        int    `short:"p" long:"progress" description:"Show a progress message each time this number of seconds have passed -- Use 0 to disable progress announcements"`
 	AcceptanceIndex bool   `long:"acceptanceindex" description:"Maintain a full hash-based acceptance index which makes the getChainFromBlock RPC available"`
@@ -58,23 +51,11 @@ func fileExists(name string) bool {
 	return true
 }
 
-// validDbType returns whether or not dbType is a supported database type.
-func validDbType(dbType string) bool {
-	for _, knownType := range knownDbTypes {
-		if dbType == knownType {
-			return true
-		}
-	}
-
-	return false
-}
-
 // loadConfig initializes and parses the config using command line options.
 func loadConfig() (*ConfigFlags, []string, error) {
 	// Default config.
 	activeConfig = &ConfigFlags{
 		DataDir:  defaultDataDir,
-		DBType:   defaultDBType,
 		InFile:   defaultDataFile,
 		Progress: defaultProgress,
 	}
@@ -95,16 +76,6 @@ func loadConfig() (*ConfigFlags, []string, error) {
 		return nil, nil, err
 	}
 
-	// Validate database type.
-	if !validDbType(activeConfig.DBType) {
-		str := "%s: The specified database type [%s] is invalid -- " +
-			"supported types %s"
-		err := errors.Errorf(str, "loadConfig", activeConfig.DBType, strings.Join(knownDbTypes, ", "))
-		fmt.Fprintln(os.Stderr, err)
-		parser.WriteHelp(os.Stderr)
-		return nil, nil, err
-	}
-
 	// Append the network type to the data directory so it is "namespaced"
 	// per network. In addition to the block database, there are other
 	// pieces of data that are saved to disk such as address manager state.

cmd/addblock/import.go

@@ -13,7 +13,6 @@ import (
 	"time"
 
 	"github.com/kaspanet/kaspad/blockdag"
-	"github.com/kaspanet/kaspad/database"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/wire"
 )
@@ -28,7 +27,6 @@ type importResults struct {
 // blockImporter houses information about an ongoing import from a block data
 // file to the block database.
 type blockImporter struct {
-	db                database.DB
 	dag               *blockdag.BlockDAG
 	r                 io.ReadSeeker
 	processQueue      chan []byte
@@ -287,7 +285,7 @@ func (bi *blockImporter) Import() chan *importResults {
 
 // newBlockImporter returns a new importer for the provided file reader seeker
 // and database.
-func newBlockImporter(db database.DB, r io.ReadSeeker) (*blockImporter, error) {
+func newBlockImporter(r io.ReadSeeker) (*blockImporter, error) {
 	// Create the acceptance index if needed.
 	var indexes []indexers.Indexer
 	if cfg.AcceptanceIndex {
@@ -302,9 +300,8 @@ func newBlockImporter(db database.DB, r io.ReadSeeker) (*blockImporter, error) {
 	}
 
 	dag, err := blockdag.New(&blockdag.Config{
-		DB:           db,
 		DAGParams:    ActiveConfig().NetParams(),
-		TimeSource:   blockdag.NewMedianTime(),
+		TimeSource:   blockdag.NewTimeSource(),
 		IndexManager: indexManager,
 	})
 	if err != nil {
@@ -312,7 +309,6 @@ func newBlockImporter(db database.DB, r io.ReadSeeker) (*blockImporter, error) {
 	}
 
 	return &blockImporter{
-		db:           db,
 		r:            r,
 		processQueue: make(chan []byte, 2),
 		doneChan:     make(chan bool),

cmd/kaspaminer/config.go

@@ -2,11 +2,13 @@ package main
 
 import (
 	"fmt"
-	"github.com/kaspanet/kaspad/config"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 
+	"github.com/kaspanet/kaspad/config"
+
 	"github.com/kaspanet/kaspad/util"
 	"github.com/pkg/errors"
 
@@ -37,6 +39,7 @@ type configFlags struct {
 	Verbose        bool   `long:"verbose" short:"v" description:"Enable logging of RPC requests"`
 	NumberOfBlocks uint64 `short:"n" long:"numblocks" description:"Number of blocks to mine. If omitted, will mine until the process is interrupted."`
 	BlockDelay     uint64 `long:"block-delay" description:"Delay for block submission (in milliseconds). This is used only for testing purposes."`
+	Profile        string `long:"profile" description:"Enable HTTP profiling on given port -- NOTE port must be between 1024 and 65536"`
 	config.NetworkFlags
 }
 
@@ -78,6 +81,13 @@ func parseConfig() (*configFlags, error) {
 		return nil, errors.New("--rpccert should be omitted if --notls is used")
 	}
 
+	if cfg.Profile != "" {
+		profilePort, err := strconv.Atoi(cfg.Profile)
+		if err != nil || profilePort < 1024 || profilePort > 65535 {
+			return nil, errors.New("The profile port must be between 1024 and 65535")
+		}
+	}
+
 	initLog(defaultLogFile, defaultErrLogFile)
 
 	return cfg, nil

cmd/kaspaminer/docker/Dockerfile

@@ -1,5 +1,5 @@
 # -- multistage docker build: stage #1: build stage
-FROM golang:1.13-alpine AS build
+FROM golang:1.14-alpine AS build
 
 RUN mkdir -p /go/src/github.com/kaspanet/kaspad
 
@@ -20,7 +20,7 @@ WORKDIR /go/src/github.com/kaspanet/kaspad/cmd/kaspaminer
 RUN GOFMT_RESULT=`go fmt ./...`; echo $GOFMT_RESULT; test -z "$GOFMT_RESULT"
 RUN go vet ./...
 RUN golint -set_exit_status ./...
-RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o kaspaminer .
+RUN GOOS=linux go build -a -installsuffix cgo -o kaspaminer .
 
 # --- multistage docker build: stage #2: runtime image
 FROM alpine

cmd/kaspaminer/main.go

@@ -2,13 +2,17 @@ package main
 
 import (
 	"fmt"
-	"github.com/kaspanet/kaspad/version"
 	"os"
 
+	"github.com/kaspanet/kaspad/version"
+
 	"github.com/pkg/errors"
 
+	_ "net/http/pprof"
+
 	"github.com/kaspanet/kaspad/signal"
 	"github.com/kaspanet/kaspad/util/panics"
+	"github.com/kaspanet/kaspad/util/profiling"
 )
 
 func main() {
@@ -28,6 +32,11 @@ func main() {
 		enableRPCLogging()
 	}
 
+	// Enable http profiling server if requested.
+	if cfg.Profile != "" {
+		profiling.Start(cfg.Profile, log)
+	}
+
 	client, err := connectToServer(cfg)
 	if err != nil {
 		panic(errors.Wrap(err, "Error connecting to the RPC server"))

cmd/txsigner/txsigner.go

@@ -4,7 +4,7 @@ import (
 	"bytes"
 	"encoding/hex"
 	"fmt"
-	"github.com/kaspanet/kaspad/ecc"
+	"github.com/kaspanet/go-secp256k1"
 	"github.com/kaspanet/kaspad/txscript"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/wire"
@@ -28,7 +28,11 @@ func main() {
 		printErrorAndExit(err, "Failed to decode transaction")
 	}
 
-	scriptPubKey, err := createScriptPubKey(privateKey.PubKey())
+	pubkey, err := privateKey.SchnorrPublicKey()
+	if err != nil {
+		printErrorAndExit(err, "Failed to generate a public key")
+	}
+	scriptPubKey, err := createScriptPubKey(pubkey)
 	if err != nil {
 		printErrorAndExit(err, "Failed to create scriptPubKey")
 	}
@@ -46,10 +50,12 @@ func main() {
 	fmt.Printf("Signed Transaction (hex): %s\n\n", serializedTransaction)
 }
 
-func parsePrivateKey(privateKeyHex string) (*ecc.PrivateKey, error) {
+func parsePrivateKey(privateKeyHex string) (*secp256k1.PrivateKey, error) {
 	privateKeyBytes, err := hex.DecodeString(privateKeyHex)
-	privateKey, _ := ecc.PrivKeyFromBytes(ecc.S256(), privateKeyBytes)
-	return privateKey, err
+	if err != nil {
+		return nil, errors.Errorf("'%s' isn't a valid hex. err: '%s' ", privateKeyHex, err)
+	}
+	return secp256k1.DeserializePrivateKeyFromSlice(privateKeyBytes)
 }
 
 func parseTransaction(transactionHex string) (*wire.MsgTx, error) {
@@ -62,8 +68,12 @@ func parseTransaction(transactionHex string) (*wire.MsgTx, error) {
 	return &transaction, err
 }
 
-func createScriptPubKey(publicKey *ecc.PublicKey) ([]byte, error) {
-	p2pkhAddress, err := util.NewAddressPubKeyHashFromPublicKey(publicKey.SerializeCompressed(), ActiveConfig().NetParams().Prefix)
+func createScriptPubKey(publicKey *secp256k1.SchnorrPublicKey) ([]byte, error) {
+	serializedKey, err := publicKey.SerializeCompressed()
+	if err != nil {
+		return nil, err
+	}
+	p2pkhAddress, err := util.NewAddressPubKeyHashFromPublicKey(serializedKey, ActiveConfig().NetParams().Prefix)
 	if err != nil {
 		return nil, err
 	}
@@ -71,7 +81,7 @@ func createScriptPubKey(publicKey *ecc.PublicKey) ([]byte, error) {
 	return scriptPubKey, err
 }
 
-func signTransaction(transaction *wire.MsgTx, privateKey *ecc.PrivateKey, scriptPubKey []byte) error {
+func signTransaction(transaction *wire.MsgTx, privateKey *secp256k1.PrivateKey, scriptPubKey []byte) error {
 	for i, transactionInput := range transaction.TxIn {
 		signatureScript, err := txscript.SignatureScript(transaction, i, scriptPubKey, txscript.SigHashAll, privateKey, true)
 		if err != nil {

config/config.go

@@ -22,7 +22,6 @@ import (
 
 	"github.com/btcsuite/go-socks/socks"
 	"github.com/jessevdk/go-flags"
-	"github.com/kaspanet/kaspad/database"
 	"github.com/kaspanet/kaspad/logger"
 	"github.com/kaspanet/kaspad/util"
 	"github.com/kaspanet/kaspad/util/network"
@@ -46,7 +45,6 @@ const (
 	defaultMaxRPCClients         = 10
 	defaultMaxRPCWebsockets      = 25
 	defaultMaxRPCConcurrentReqs  = 20
-	defaultDbType                = "ffldb"
 	defaultBlockMaxMass          = 10000000
 	blockMaxMassMin              = 1000
 	blockMaxMassMax              = 10000000
@@ -65,7 +63,6 @@ var (
 
 	defaultConfigFile  = filepath.Join(DefaultHomeDir, defaultConfigFilename)
 	defaultDataDir     = filepath.Join(DefaultHomeDir, defaultDataDirname)
-	knownDbTypes       = database.SupportedDrivers()
 	defaultRPCKeyFile  = filepath.Join(DefaultHomeDir, "rpc.key")
 	defaultRPCCertFile = filepath.Join(DefaultHomeDir, "rpc.cert")
 	defaultLogDir      = filepath.Join(DefaultHomeDir, defaultLogDirname)
@@ -168,17 +165,6 @@ func cleanAndExpandPath(path string) string {
 	return filepath.Clean(os.ExpandEnv(path))
 }
 
-// validDbType returns whether or not dbType is a supported database type.
-func validDbType(dbType string) bool {
-	for _, knownType := range knownDbTypes {
-		if dbType == knownType {
-			return true
-		}
-	}
-
-	return false
-}
-
 // newConfigParser returns a new command line flags parser.
 func newConfigParser(cfgFlags *Flags, so *serviceOptions, options flags.Options) *flags.Parser {
 	parser := flags.NewParser(cfgFlags, options)
@@ -235,7 +221,6 @@ func loadConfig() (*Config, []string, error) {
 		RPCMaxConcurrentReqs: defaultMaxRPCConcurrentReqs,
 		DataDir:              defaultDataDir,
 		LogDir:               defaultLogDir,
-		DbType:               defaultDbType,
 		RPCKey:               defaultRPCKeyFile,
 		RPCCert:              defaultRPCCertFile,
 		BlockMaxMass:         defaultBlockMaxMass,
@@ -424,16 +409,6 @@ func loadConfig() (*Config, []string, error) {
 		return nil, nil, err
 	}
 
-	// Validate database type.
-	if !validDbType(activeConfig.DbType) {
-		str := "%s: The specified database type [%s] is invalid -- " +
-			"supported types %s"
-		err := errors.Errorf(str, funcName, activeConfig.DbType, knownDbTypes)
-		fmt.Fprintln(os.Stderr, err)
-		fmt.Fprintln(os.Stderr, usageMessage)
-		return nil, nil, err
-	}
-
 	// Validate profile port number
 	if activeConfig.Profile != "" {
 		profilePort, err := strconv.Atoi(activeConfig.Profile)

dagconfig/params.go

@@ -13,7 +13,6 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/kaspanet/kaspad/util"
-	"github.com/kaspanet/kaspad/util/hdkeychain"
 
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
@@ -177,13 +176,6 @@ type Params struct {
 
 	// Address encoding magics
 	PrivateKeyID byte // First byte of a WIF private key
-
-	// BIP32 hierarchical deterministic extended key magics
-	HDKeyIDPair hdkeychain.HDKeyIDPair
-
-	// BIP44 coin type used in the hierarchical deterministic path for
-	// address generation.
-	HDCoinType uint32
 }
 
 // NormalizeRPCServerAddress returns addr with the current network default
@@ -238,13 +230,6 @@ var MainnetParams = Params{
 
 	// Address encoding magics
 	PrivateKeyID: 0x80, // starts with 5 (uncompressed) or K (compressed)
-
-	// BIP32 hierarchical deterministic extended key magics
-	HDKeyIDPair: hdkeychain.HDKeyPairMainnet,
-
-	// BIP44 coin type used in the hierarchical deterministic path for
-	// address generation.
-	HDCoinType: 0,
 }
 
 // RegressionNetParams defines the network parameters for the regression test
@@ -295,13 +280,6 @@ var RegressionNetParams = Params{
 
 	// Address encoding magics
 	PrivateKeyID: 0xef, // starts with 9 (uncompressed) or c (compressed)
-
-	// BIP32 hierarchical deterministic extended key magics
-	HDKeyIDPair: hdkeychain.HDKeyPairRegressionNet,
-
-	// BIP44 coin type used in the hierarchical deterministic path for
-	// address generation.
-	HDCoinType: 1,
 }
 
 // TestnetParams defines the network parameters for the test Kaspa network.
@@ -350,13 +328,6 @@ var TestnetParams = Params{
 
 	// Address encoding magics
 	PrivateKeyID: 0xef, // starts with 9 (uncompressed) or c (compressed)
-
-	// BIP32 hierarchical deterministic extended key magics
-	HDKeyIDPair: hdkeychain.HDKeyPairTestnet,
-
-	// BIP44 coin type used in the hierarchical deterministic path for
-	// address generation.
-	HDCoinType: 1,
 }
 
 // SimnetParams defines the network parameters for the simulation test Kaspa
@@ -409,13 +380,6 @@ var SimnetParams = Params{
 	PrivateKeyID: 0x64, // starts with 4 (uncompressed) or F (compressed)
 	// Human-readable part for Bech32 encoded addresses
 	Prefix: util.Bech32PrefixKaspaSim,
-
-	// BIP32 hierarchical deterministic extended key magics
-	HDKeyIDPair: hdkeychain.HDKeyPairSimnet,
-
-	// BIP44 coin type used in the hierarchical deterministic path for
-	// address generation.
-	HDCoinType: 115, // ASCII for s
 }
 
 // DevnetParams defines the network parameters for the development Kaspa network.
@@ -464,13 +428,6 @@ var DevnetParams = Params{
 
 	// Address encoding magics
 	PrivateKeyID: 0xef, // starts with 9 (uncompressed) or c (compressed)
-
-	// BIP32 hierarchical deterministic extended key magics
-	HDKeyIDPair: hdkeychain.HDKeyPairDevnet,
-
-	// BIP44 coin type used in the hierarchical deterministic path for
-	// address generation.
-	HDCoinType: 1,
 }
 
 var (

dagconfig/register_test.go

@@ -1,9 +1,6 @@
 package dagconfig_test
 
 import (
-	"bytes"
-	"github.com/kaspanet/kaspad/util/hdkeychain"
-	"reflect"
 	"testing"
 
 	. "github.com/kaspanet/kaspad/dagconfig"
@@ -15,10 +12,6 @@ import (
 var mockNetParams = Params{
 	Name: "mocknet",
 	Net:  1<<32 - 1,
-	HDKeyIDPair: hdkeychain.HDKeyIDPair{
-		PrivateKeyID: [4]byte{0x01, 0x02, 0x03, 0x04},
-		PublicKeyID:  [4]byte{0x05, 0x06, 0x07, 0x08},
-	},
 }
 
 func TestRegister(t *testing.T) {
@@ -27,16 +20,10 @@ func TestRegister(t *testing.T) {
 		params *Params
 		err    error
 	}
-	type hdTest struct {
-		priv []byte
-		want []byte
-		err  error
-	}
 
 	tests := []struct {
 		name     string
 		register []registerTest
-		hdMagics []hdTest
 	}{
 		{
 			name: "default networks",
@@ -62,40 +49,6 @@ func TestRegister(t *testing.T) {
 					err:    ErrDuplicateNet,
 				},
 			},
-			hdMagics: []hdTest{
-				{
-					priv: MainnetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: MainnetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-				{
-					priv: TestnetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: TestnetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-				{
-					priv: RegressionNetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: RegressionNetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-				{
-					priv: SimnetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: SimnetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-				{
-					priv: mockNetParams.HDKeyIDPair.PrivateKeyID[:],
-					err:  hdkeychain.ErrUnknownHDKeyID,
-				},
-				{
-					priv: []byte{0xff, 0xff, 0xff, 0xff},
-					err:  hdkeychain.ErrUnknownHDKeyID,
-				},
-				{
-					priv: []byte{0xff},
-					err:  hdkeychain.ErrUnknownHDKeyID,
-				},
-			},
 		},
 		{
 			name: "register mocknet",
@@ -106,13 +59,6 @@ func TestRegister(t *testing.T) {
 					err:    nil,
 				},
 			},
-			hdMagics: []hdTest{
-				{
-					priv: mockNetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: mockNetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-			},
 		},
 		{
 			name: "more duplicates",
@@ -143,41 +89,6 @@ func TestRegister(t *testing.T) {
 					err:    ErrDuplicateNet,
 				},
 			},
-			hdMagics: []hdTest{
-				{
-					priv: MainnetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: MainnetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-				{
-					priv: TestnetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: TestnetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-				{
-					priv: RegressionNetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: RegressionNetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-				{
-					priv: SimnetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: SimnetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-				{
-					priv: mockNetParams.HDKeyIDPair.PrivateKeyID[:],
-					want: mockNetParams.HDKeyIDPair.PublicKeyID[:],
-					err:  nil,
-				},
-				{
-					priv: []byte{0xff, 0xff, 0xff, 0xff},
-					err:  hdkeychain.ErrUnknownHDKeyID,
-				},
-				{
-					priv: []byte{0xff},
-					err:  hdkeychain.ErrUnknownHDKeyID,
-				},
-			},
 		},
 	}
 
@@ -185,25 +96,10 @@ func TestRegister(t *testing.T) {
 		for _, regtest := range test.register {
 			err := Register(regtest.params)
 
-			// HDKeyIDPairs must be registered separately
-			hdkeychain.RegisterHDKeyIDPair(regtest.params.HDKeyIDPair)
-
 			if err != regtest.err {
 				t.Errorf("%s:%s: Registered network with unexpected error: got %v expected %v",
 					test.name, regtest.name, err, regtest.err)
 			}
 		}
-		for i, magTest := range test.hdMagics {
-			pubKey, err := hdkeychain.HDPrivateKeyToPublicKeyID(magTest.priv[:])
-			if !reflect.DeepEqual(err, magTest.err) {
-				t.Errorf("%s: HD magic %d mismatched error: got %v expected %v ",
-					test.name, i, err, magTest.err)
-				continue
-			}
-			if magTest.err == nil && !bytes.Equal(pubKey, magTest.want[:]) {
-				t.Errorf("%s: HD magic %d private and public mismatch: got %v expected %v ",
-					test.name, i, pubKey, magTest.want[:])
-			}
-		}
 	}
 }

database/README.md

@@ -4,29 +4,35 @@ database
 [![ISC License](http://img.shields.io/badge/license-ISC-blue.svg)](https://choosealicense.com/licenses/isc/)
 [![GoDoc](https://img.shields.io/badge/godoc-reference-blue.svg)](http://godoc.org/github.com/kaspanet/kaspad/database)
 
-Package database provides a block and metadata storage database.
+Package database provides a database for kaspad.
 
-Please note that this package is intended to enable kaspad to support different
-database backends and is not something that a client can directly access as only
-one entity can have the database open at a time (for most database backends),
-and that entity will be kaspad.
+Overview
+--------
+This package provides a database layer to store and retrieve data in a simple
+and efficient manner.
 
-When a client wants programmatic access to the data provided by kaspad, they'll
-likely want to use the [rpcclient](https://github.com/kaspanet/kaspad/tree/master/rpcclient)
-package which makes use of the [JSON-RPC API](https://github.com/kaspanet/kaspad/tree/master/docs/json_rpc_api.md).
+The current backend is ffldb, which makes use of leveldb, flat files, and strict
+checksums in key areas to ensure data integrity.
 
-The default backend, ffldb, has a strong focus on speed, efficiency, and
-robustness. It makes use of leveldb for the metadata, flat files for block
-storage, and strict checksums in key areas to ensure data integrity.
+Implementors of additional backends are required to implement the following interfaces:
 
-## Feature Overview
+DataAccessor
+------------
+This defines the common interface by which data gets accessed in a generic kaspad
+database. Both the Database and the Transaction interfaces (see below) implement it.
 
-- Key/value metadata store
-- Kaspa block storage
-- Efficient retrieval of block headers and regions (transactions, scripts, etc)
-- Read-only and read-write transactions with both manual and managed modes
-- Nested buckets
-- Iteration support including cursors with seek capability
-- Supports registration of backend databases
-- Comprehensive test coverage
+Database
+--------
+This defines the interface of a database that can begin transactions and close itself.
 
+Transaction
+-----------
+This defines the interface of a generic kaspad database transaction.
+
+Note: Transactions provide data consistency over the state of the database as it was
+when the transaction started. There is NO guarantee that if one puts data into the
+transaction then it will be available to get within the same transaction.
+
+Cursor
+------
+This iterates over database entries given some bucket.

database/bucket.go

@@ -0,0 +1,51 @@
+package database
+
+import "bytes"
+
+var separator = []byte("/")
+
+// Bucket is a helper type meant to combine buckets,
+// sub-buckets, and keys into a single full key-value
+// database key.
+type Bucket struct {
+	path [][]byte
+}
+
+// MakeBucket creates a new Bucket using the given path
+// of buckets.
+func MakeBucket(path ...[]byte) *Bucket {
+	return &Bucket{path: path}
+}
+
+// Bucket returns the sub-bucket of the current bucket
+// defined by bucketBytes.
+func (b *Bucket) Bucket(bucketBytes []byte) *Bucket {
+	newPath := make([][]byte, len(b.path)+1)
+	copy(newPath, b.path)
+	copy(newPath[len(b.path):], [][]byte{bucketBytes})
+
+	return MakeBucket(newPath...)
+}
+
+// Key returns the key inside of the current bucket.
+func (b *Bucket) Key(key []byte) []byte {
+	bucketPath := b.Path()
+
+	fullKeyLength := len(bucketPath) + len(key)
+	fullKey := make([]byte, fullKeyLength)
+	copy(fullKey, bucketPath)
+	copy(fullKey[len(bucketPath):], key)
+
+	return fullKey
+}
+
+// Path returns the full path of the current bucket.
+func (b *Bucket) Path() []byte {
+	bucketPath := bytes.Join(b.path, separator)
+
+	bucketPathWithFinalSeparator := make([]byte, len(bucketPath)+len(separator))
+	copy(bucketPathWithFinalSeparator, bucketPath)
+	copy(bucketPathWithFinalSeparator[len(bucketPath):], separator)
+
+	return bucketPathWithFinalSeparator
+}

database/bucket_test.go

@@ -0,0 +1,69 @@
+package database
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestBucketPath(t *testing.T) {
+	tests := []struct {
+		bucketByteSlices [][]byte
+		expectedPath     []byte
+	}{
+		{
+			bucketByteSlices: [][]byte{[]byte("hello")},
+			expectedPath:     []byte("hello/"),
+		},
+		{
+			bucketByteSlices: [][]byte{[]byte("hello"), []byte("world")},
+			expectedPath:     []byte("hello/world/"),
+		},
+	}
+
+	for _, test := range tests {
+		// Build a result using the MakeBucket function alone
+		resultKey := MakeBucket(test.bucketByteSlices...).Path()
+		if !reflect.DeepEqual(resultKey, test.expectedPath) {
+			t.Errorf("TestBucketPath: got wrong path using MakeBucket. "+
+				"Want: %s, got: %s", string(test.expectedPath), string(resultKey))
+		}
+
+		// Build a result using sub-Bucket calls
+		bucket := MakeBucket()
+		for _, bucketBytes := range test.bucketByteSlices {
+			bucket = bucket.Bucket(bucketBytes)
+		}
+		resultKey = bucket.Path()
+		if !reflect.DeepEqual(resultKey, test.expectedPath) {
+			t.Errorf("TestBucketPath: got wrong path using sub-Bucket "+
+				"calls. Want: %s, got: %s", string(test.expectedPath), string(resultKey))
+		}
+	}
+}
+
+func TestBucketKey(t *testing.T) {
+	tests := []struct {
+		bucketByteSlices [][]byte
+		key              []byte
+		expectedKey      []byte
+	}{
+		{
+			bucketByteSlices: [][]byte{[]byte("hello")},
+			key:              []byte("test"),
+			expectedKey:      []byte("hello/test"),
+		},
+		{
+			bucketByteSlices: [][]byte{[]byte("hello"), []byte("world")},
+			key:              []byte("test"),
+			expectedKey:      []byte("hello/world/test"),
+		},
+	}
+
+	for _, test := range tests {
+		resultKey := MakeBucket(test.bucketByteSlices...).Key(test.key)
+		if !reflect.DeepEqual(resultKey, test.expectedKey) {
+			t.Errorf("TestBucketKey: got wrong key. Want: %s, got: %s",
+				string(test.expectedKey), string(resultKey))
+		}
+	}
+}

database/cmd/dbtool/fetchblock.go

@@ -1,62 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package main
-
-import (
-	"encoding/hex"
-	"github.com/pkg/errors"
-	"time"
-
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/util/daghash"
-)
-
-// fetchBlockCmd defines the configuration options for the fetchblock command.
-type fetchBlockCmd struct{}
-
-var (
-	// fetchBlockCfg defines the configuration options for the command.
-	fetchBlockCfg = fetchBlockCmd{}
-)
-
-// Execute is the main entry point for the command. It's invoked by the parser.
-func (cmd *fetchBlockCmd) Execute(args []string) error {
-	// Setup the global config options and ensure they are valid.
-	if err := setupGlobalConfig(); err != nil {
-		return err
-	}
-
-	if len(args) < 1 {
-		return errors.New("required block hash parameter not specified")
-	}
-	blockHash, err := daghash.NewHashFromStr(args[0])
-	if err != nil {
-		return err
-	}
-
-	// Load the block database.
-	db, err := loadBlockDB()
-	if err != nil {
-		return err
-	}
-	defer db.Close()
-
-	return db.View(func(dbTx database.Tx) error {
-		log.Infof("Fetching block %s", blockHash)
-		startTime := time.Now()
-		blockBytes, err := dbTx.FetchBlock(blockHash)
-		if err != nil {
-			return err
-		}
-		log.Infof("Loaded block in %s", time.Since(startTime))
-		log.Infof("Block Hex: %s", hex.EncodeToString(blockBytes))
-		return nil
-	})
-}
-
-// Usage overrides the usage display for the command.
-func (cmd *fetchBlockCmd) Usage() string {
-	return "<block-hash>"
-}

database/cmd/dbtool/fetchblockregion.go

@@ -1,90 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package main
-
-import (
-	"encoding/hex"
-	"github.com/pkg/errors"
-	"strconv"
-	"time"
-
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/util/daghash"
-)
-
-// blockRegionCmd defines the configuration options for the fetchblockregion
-// command.
-type blockRegionCmd struct{}
-
-var (
-	// blockRegionCfg defines the configuration options for the command.
-	blockRegionCfg = blockRegionCmd{}
-)
-
-// Execute is the main entry point for the command. It's invoked by the parser.
-func (cmd *blockRegionCmd) Execute(args []string) error {
-	// Setup the global config options and ensure they are valid.
-	if err := setupGlobalConfig(); err != nil {
-		return err
-	}
-
-	// Ensure expected arguments.
-	if len(args) < 1 {
-		return errors.New("required block hash parameter not specified")
-	}
-	if len(args) < 2 {
-		return errors.New("required start offset parameter not " +
-			"specified")
-	}
-	if len(args) < 3 {
-		return errors.New("required region length parameter not " +
-			"specified")
-	}
-
-	// Parse arguments.
-	blockHash, err := daghash.NewHashFromStr(args[0])
-	if err != nil {
-		return err
-	}
-	startOffset, err := strconv.ParseUint(args[1], 10, 32)
-	if err != nil {
-		return err
-	}
-	regionLen, err := strconv.ParseUint(args[2], 10, 32)
-	if err != nil {
-		return err
-	}
-
-	// Load the block database.
-	db, err := loadBlockDB()
-	if err != nil {
-		return err
-	}
-	defer db.Close()
-
-	return db.View(func(dbTx database.Tx) error {
-		log.Infof("Fetching block region %s<%d:%d>", blockHash,
-			startOffset, startOffset+regionLen-1)
-		region := database.BlockRegion{
-			Hash:   blockHash,
-			Offset: uint32(startOffset),
-			Len:    uint32(regionLen),
-		}
-		startTime := time.Now()
-		regionBytes, err := dbTx.FetchBlockRegion(&region)
-		if err != nil {
-			return err
-		}
-		log.Infof("Loaded block region in %s", time.Since(startTime))
-		log.Infof("Double Hash: %s", daghash.DoubleHashH(regionBytes))
-		log.Infof("Region Hex: %s", hex.EncodeToString(regionBytes))
-		return nil
-	})
-}
-
-// Usage overrides the usage display for the command.
-func (cmd *blockRegionCmd) Usage() string {
-	return "<block-hash> <start-offset> <length-of-region>"
-}

database/cmd/dbtool/globalconfig.go

@@ -1,111 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package main
-
-import (
-	"github.com/pkg/errors"
-	"os"
-	"path/filepath"
-	"strings"
-
-	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
-	_ "github.com/kaspanet/kaspad/database/ffldb"
-	"github.com/kaspanet/kaspad/util"
-)
-
-var (
-	kaspadHomeDir   = util.AppDataDir("kaspad", false)
-	knownDbTypes    = database.SupportedDrivers()
-	activeNetParams = &dagconfig.MainnetParams
-
-	// Default global config.
-	cfg = &config{
-		DataDir: filepath.Join(kaspadHomeDir, "data"),
-		DbType:  "ffldb",
-	}
-)
-
-// config defines the global configuration options.
-type config struct {
-	DataDir        string `short:"b" long:"datadir" description:"Location of the kaspad data directory"`
-	DbType         string `long:"dbtype" description:"Database backend to use for the Block DAG"`
-	Testnet        bool   `long:"testnet" description:"Use the test network"`
-	RegressionTest bool   `long:"regtest" description:"Use the regression test network"`
-	Simnet         bool   `long:"simnet" description:"Use the simulation test network"`
-	Devnet         bool   `long:"devnet" description:"Use the development test network"`
-}
-
-// fileExists reports whether the named file or directory exists.
-func fileExists(name string) bool {
-	if _, err := os.Stat(name); err != nil {
-		if os.IsNotExist(err) {
-			return false
-		}
-	}
-	return true
-}
-
-// validDbType returns whether or not dbType is a supported database type.
-func validDbType(dbType string) bool {
-	for _, knownType := range knownDbTypes {
-		if dbType == knownType {
-			return true
-		}
-	}
-
-	return false
-}
-
-// setupGlobalConfig examine the global configuration options for any conditions
-// which are invalid as well as performs any addition setup necessary after the
-// initial parse.
-func setupGlobalConfig() error {
-	// Multiple networks can't be selected simultaneously.
-	// Count number of network flags passed; assign active network params
-	// while we're at it
-	numNets := 0
-	if cfg.Testnet {
-		numNets++
-		activeNetParams = &dagconfig.TestnetParams
-	}
-	if cfg.RegressionTest {
-		numNets++
-		activeNetParams = &dagconfig.RegressionNetParams
-	}
-	if cfg.Simnet {
-		numNets++
-		activeNetParams = &dagconfig.SimnetParams
-	}
-	if cfg.Devnet {
-		numNets++
-		activeNetParams = &dagconfig.DevnetParams
-	}
-	if numNets > 1 {
-		return errors.New("The testnet, regtest, simnet and devnet params " +
-			"can't be used together -- choose one of the four")
-	}
-
-	if numNets == 0 {
-		return errors.New("Mainnet has not launched yet, use --testnet to run in testnet mode")
-	}
-
-	// Validate database type.
-	if !validDbType(cfg.DbType) {
-		str := "The specified database type [%s] is invalid -- " +
-			"supported types: %s"
-		return errors.Errorf(str, cfg.DbType, strings.Join(knownDbTypes, ", "))
-	}
-
-	// Append the network type to the data directory so it is "namespaced"
-	// per network. In addition to the block database, there are other
-	// pieces of data that are saved to disk such as address manager state.
-	// All data is specific to a network, so namespacing the data directory
-	// means each individual piece of serialized data does not have to
-	// worry about changing names per network and such.
-	cfg.DataDir = filepath.Join(cfg.DataDir, activeNetParams.Name)
-
-	return nil
-}

database/cmd/dbtool/main.go

@@ -1,113 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package main
-
-import (
-	"github.com/kaspanet/kaspad/util/panics"
-	"github.com/pkg/errors"
-	"os"
-	"path/filepath"
-	"runtime"
-	"strings"
-
-	"github.com/jessevdk/go-flags"
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/logger"
-	"github.com/kaspanet/kaspad/logs"
-)
-
-const (
-	// blockDbNamePrefix is the prefix for the kaspad block database.
-	blockDbNamePrefix = "blocks"
-)
-
-var (
-	log             *logs.Logger
-	spawn           func(func())
-	shutdownChannel = make(chan error)
-)
-
-// loadBlockDB opens the block database and returns a handle to it.
-func loadBlockDB() (database.DB, error) {
-	// The database name is based on the database type.
-	dbName := blockDbNamePrefix + "_" + cfg.DbType
-	dbPath := filepath.Join(cfg.DataDir, dbName)
-
-	log.Infof("Loading block database from '%s'", dbPath)
-	db, err := database.Open(cfg.DbType, dbPath, activeNetParams.Net)
-	if err != nil {
-		// Return the error if it's not because the database doesn't
-		// exist.
-		var dbErr database.Error
-		if ok := errors.As(err, &dbErr); !ok || dbErr.ErrorCode !=
-			database.ErrDbDoesNotExist {
-
-			return nil, err
-		}
-
-		// Create the db if it does not exist.
-		err = os.MkdirAll(cfg.DataDir, 0700)
-		if err != nil {
-			return nil, err
-		}
-		db, err = database.Create(cfg.DbType, dbPath, activeNetParams.Net)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	log.Info("Block database loaded")
-	return db, nil
-}
-
-// realMain is the real main function for the utility. It is necessary to work
-// around the fact that deferred functions do not run when os.Exit() is called.
-func realMain() error {
-	// Setup logging.
-	backendLogger := logs.NewBackend()
-	defer os.Stdout.Sync()
-	log = backendLogger.Logger("MAIN")
-	spawn = panics.GoroutineWrapperFunc(log)
-	dbLog, _ := logger.Get(logger.SubsystemTags.KSDB)
-	dbLog.SetLevel(logs.LevelDebug)
-
-	// Setup the parser options and commands.
-	appName := filepath.Base(os.Args[0])
-	appName = strings.TrimSuffix(appName, filepath.Ext(appName))
-	parserFlags := flags.Options(flags.HelpFlag | flags.PassDoubleDash)
-	parser := flags.NewNamedParser(appName, parserFlags)
-	parser.AddGroup("Global Options", "", cfg)
-	parser.AddCommand("fetchblock",
-		"Fetch the specific block hash from the database", "",
-		&fetchBlockCfg)
-	parser.AddCommand("fetchblockregion",
-		"Fetch the specified block region from the database", "",
-		&blockRegionCfg)
-
-	// Parse command line and invoke the Execute function for the specified
-	// command.
-	if _, err := parser.Parse(); err != nil {
-		var flagsErr *flags.Error
-		if ok := errors.As(err, &flagsErr); ok && flagsErr.Type == flags.ErrHelp {
-			parser.WriteHelp(os.Stderr)
-		} else {
-			log.Error(err)
-		}
-
-		return err
-	}
-
-	return nil
-}
-
-func main() {
-	// Use all processor cores.
-	runtime.GOMAXPROCS(runtime.NumCPU())
-
-	// Work around defer not working after os.Exit()
-	if err := realMain(); err != nil {
-		os.Exit(1)
-	}
-}

database/cmd/dbtool/signal.go

@@ -1,82 +0,0 @@
-// Copyright (c) 2013-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package main
-
-import (
-	"os"
-	"os/signal"
-)
-
-// interruptChannel is used to receive SIGINT (Ctrl+C) signals.
-var interruptChannel chan os.Signal
-
-// addHandlerChannel is used to add an interrupt handler to the list of handlers
-// to be invoked on SIGINT (Ctrl+C) signals.
-var addHandlerChannel = make(chan func())
-
-// mainInterruptHandler listens for SIGINT (Ctrl+C) signals on the
-// interruptChannel and invokes the registered interruptCallbacks accordingly.
-// It also listens for callback registration. It must be run as a goroutine.
-func mainInterruptHandler() {
-	// interruptCallbacks is a list of callbacks to invoke when a
-	// SIGINT (Ctrl+C) is received.
-	var interruptCallbacks []func()
-
-	// isShutdown is a flag which is used to indicate whether or not
-	// the shutdown signal has already been received and hence any future
-	// attempts to add a new interrupt handler should invoke them
-	// immediately.
-	var isShutdown bool
-
-	for {
-		select {
-		case <-interruptChannel:
-			// Ignore more than one shutdown signal.
-			if isShutdown {
-				log.Infof("Received SIGINT (Ctrl+C). " +
-					"Already shutting down...")
-				continue
-			}
-
-			isShutdown = true
-			log.Infof("Received SIGINT (Ctrl+C). Shutting down...")
-
-			// Run handlers in LIFO order.
-			for i := range interruptCallbacks {
-				idx := len(interruptCallbacks) - 1 - i
-				callback := interruptCallbacks[idx]
-				callback()
-			}
-
-			// Signal the main goroutine to shutdown.
-			spawn(func() {
-				shutdownChannel <- nil
-			})
-
-		case handler := <-addHandlerChannel:
-			// The shutdown signal has already been received, so
-			// just invoke and new handlers immediately.
-			if isShutdown {
-				handler()
-			}
-
-			interruptCallbacks = append(interruptCallbacks, handler)
-		}
-	}
-}
-
-// addInterruptHandler adds a handler to call when a SIGINT (Ctrl+C) is
-// received.
-func addInterruptHandler(handler func()) {
-	// Create the channel and start the main interrupt handler which invokes
-	// all other callbacks and exits if not already done.
-	if interruptChannel == nil {
-		interruptChannel = make(chan os.Signal, 1)
-		signal.Notify(interruptChannel, os.Interrupt)
-		spawn(mainInterruptHandler)
-	}
-
-	addHandlerChannel <- handler
-}

database/cursor.go

@@ -0,0 +1,31 @@
+package database
+
+// Cursor iterates over database entries given some bucket.
+type Cursor interface {
+	// Next moves the iterator to the next key/value pair. It returns whether the
+	// iterator is exhausted. Returns false if the cursor is closed.
+	Next() bool
+
+	// First moves the iterator to the first key/value pair. It returns false if
+	// such a pair does not exist or if the cursor is closed.
+	First() bool
+
+	// Seek moves the iterator to the first key/value pair whose key is greater
+	// than or equal to the given key. It returns ErrNotFound if such pair does not
+	// exist.
+	Seek(key []byte) error
+
+	// Key returns the key of the current key/value pair, or ErrNotFound if done.
+	// Note that the key is trimmed to not include the prefix the cursor was opened
+	// with. The caller should not modify the contents of the returned slice, and
+	// its contents may change on the next call to Next.
+	Key() ([]byte, error)
+
+	// Value returns the value of the current key/value pair, or ErrNotFound if done.
+	// The caller should not modify the contents of the returned slice, and its
+	// contents may change on the next call to Next.
+	Value() ([]byte, error)
+
+	// Close releases associated resources.
+	Close() error
+}

database/dataaccessor.go

@@ -0,0 +1,36 @@
+package database
+
+// DataAccessor defines the common interface by which data gets
+// accessed in a generic kaspad database.
+type DataAccessor interface {
+	// Put sets the value for the given key. It overwrites
+	// any previous value for that key.
+	Put(key []byte, value []byte) error
+
+	// Get gets the value for the given key. It returns
+	// ErrNotFound if the given key does not exist.
+	Get(key []byte) ([]byte, error)
+
+	// Has returns true if the database does contains the
+	// given key.
+	Has(key []byte) (bool, error)
+
+	// Delete deletes the value for the given key. Will not
+	// return an error if the key doesn't exist.
+	Delete(key []byte) error
+
+	// AppendToStore appends the given data to the store
+	// defined by storeName. This function returns a serialized
+	// location handle that's meant to be stored and later used
+	// when querying the data that has just now been inserted.
+	AppendToStore(storeName string, data []byte) ([]byte, error)
+
+	// RetrieveFromStore retrieves data from the store defined by
+	// storeName using the given serialized location handle. It
+	// returns ErrNotFound if the location does not exist. See
+	// AppendToStore for further details.
+	RetrieveFromStore(storeName string, location []byte) ([]byte, error)
+
+	// Cursor begins a new cursor over the given bucket.
+	Cursor(bucket []byte) (Cursor, error)
+}

database/database.go

@@ -0,0 +1,19 @@
+package database
+
+// Database defines the interface of a database that can begin
+// transactions and close itself.
+//
+// Important: This is not part of the DataAccessor interface
+// because the Transaction interface includes it. Were we to
+// merge Database with DataAccessor, implementors of the
+// Transaction interface would be forced to implement methods
+// such as Begin and Close, which is undesirable.
+type Database interface {
+	DataAccessor
+
+	// Begin begins a new database transaction.
+	Begin() (Transaction, error)
+
+	// Close closes the database.
+	Close() error
+}

database/doc.go

@@ -1,85 +1,34 @@
 /*
-Package database provides a block and metadata storage database.
+Package database provides a database for kaspad.
 
 Overview
 
-This package provides a database layer to store and retrieve this data in a
-simple and efficient manner.
+This package provides a database layer to store and retrieve data in a simple
+and efficient manner.
 
-The default backend, ffldb, has a strong focus on speed, efficiency, and
-robustness. It makes use leveldb for the metadata, flat files for block
-storage, and strict checksums in key areas to ensure data integrity.
+The current backend is ffldb, which makes use of leveldb, flat files, and strict
+checksums in key areas to ensure data integrity.
 
-A quick overview of the features database provides are as follows:
+Implementors of additional backends are required to implement the following interfaces:
 
- - Key/value metadata store
- - Kaspa block storage
- - Efficient retrieval of block headers and regions (transactions, scripts, etc)
- - Read-only and read-write transactions with both manual and managed modes
- - Nested buckets
- - Supports registration of backend databases
- - Comprehensive test coverage
+DataAccessor
+
+This defines the common interface by which data gets accessed in a generic kaspad
+database. Both the Database and the Transaction interfaces (see below) implement it.
 
 Database
 
-The main entry point is the DB interface. It exposes functionality for
-transactional-based access and storage of metadata and block data. It is
-obtained via the Create and Open functions which take a database type string
-that identifies the specific database driver (backend) to use as well as
-arguments specific to the specified driver.
+This defines the interface of a database that can begin transactions and close itself.
 
-The interface provides facilities for obtaining transactions (the Tx interface)
-that are the basis of all database reads and writes. Unlike some database
-interfaces that support reading and writing without transactions, this interface
-requires transactions even when only reading or writing a single key.
+Transaction
 
-The Begin function provides an unmanaged transaction while the View and Update
-functions provide a managed transaction. These are described in more detail
-below.
+This defines the interface of a generic kaspad database transaction.
+Note: transactions provide data consistency over the state of the database as it was
+when the transaction started. There is NO guarantee that if one puts data into the
+transaction then it will be available to get within the same transaction.
 
-Transactions
+Cursor
 
-The Tx interface provides facilities for rolling back or committing changes that
-took place while the transaction was active. It also provides the root metadata
-bucket under which all keys, values, and nested buckets are stored. A
-transaction can either be read-only or read-write and managed or unmanaged.
-
-Managed versus Unmanaged Transactions
-
-A managed transaction is one where the caller provides a function to execute
-within the context of the transaction and the commit or rollback is handled
-automatically depending on whether or not the provided function returns an
-error. Attempting to manually call Rollback or Commit on the managed
-transaction will result in a panic.
-
-An unmanaged transaction, on the other hand, requires the caller to manually
-call Commit or Rollback when they are finished with it. Leaving transactions
-open for long periods of time can have several adverse effects, so it is
-recommended that managed transactions are used instead.
-
-Buckets
-
-The Bucket interface provides the ability to manipulate key/value pairs and
-nested buckets as well as iterate through them.
-
-The Get, Put, and Delete functions work with key/value pairs, while the Bucket,
-CreateBucket, CreateBucketIfNotExists, and DeleteBucket functions work with
-buckets. The ForEach function allows the caller to provide a function to be
-called with each key/value pair and nested bucket in the current bucket.
-
-Metadata Bucket
-
-As discussed above, all of the functions which are used to manipulate key/value
-pairs and nested buckets exist on the Bucket interface. The root metadata
-bucket is the upper-most bucket in which data is stored and is created at the
-same time as the database. Use the Metadata function on the Tx interface
-to retrieve it.
-
-Nested Buckets
-
-The CreateBucket and CreateBucketIfNotExists functions on the Bucket interface
-provide the ability to create an arbitrary number of nested buckets. It is
-a good idea to avoid a lot of buckets with little data in them as it could lead
-to poor page utilization depending on the specific driver in use.
+This iterates over database entries given some bucket.
 */
 package database

database/driver.go

@@ -1,84 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package database
-
-import (
-	"fmt"
-)
-
-// Driver defines a structure for backend drivers to use when they registered
-// themselves as a backend which implements the DB interface.
-type Driver struct {
-	// DbType is the identifier used to uniquely identify a specific
-	// database driver. There can be only one driver with the same name.
-	DbType string
-
-	// Create is the function that will be invoked with all user-specified
-	// arguments to create the database. This function must return
-	// ErrDbExists if the database already exists.
-	Create func(args ...interface{}) (DB, error)
-
-	// Open is the function that will be invoked with all user-specified
-	// arguments to open the database. This function must return
-	// ErrDbDoesNotExist if the database has not already been created.
-	Open func(args ...interface{}) (DB, error)
-}
-
-// driverList holds all of the registered database backends.
-var drivers = make(map[string]*Driver)
-
-// RegisterDriver adds a backend database driver to available interfaces.
-// ErrDbTypeRegistered will be returned if the database type for the driver has
-// already been registered.
-func RegisterDriver(driver Driver) error {
-	if _, exists := drivers[driver.DbType]; exists {
-		str := fmt.Sprintf("driver %q is already registered",
-			driver.DbType)
-		return makeError(ErrDbTypeRegistered, str, nil)
-	}
-
-	drivers[driver.DbType] = &driver
-	return nil
-}
-
-// SupportedDrivers returns a slice of strings that represent the database
-// drivers that have been registered and are therefore supported.
-func SupportedDrivers() []string {
-	supportedDBs := make([]string, 0, len(drivers))
-	for _, drv := range drivers {
-		supportedDBs = append(supportedDBs, drv.DbType)
-	}
-	return supportedDBs
-}
-
-// Create initializes and opens a database for the specified type. The
-// arguments are specific to the database type driver. See the documentation
-// for the database driver for further details.
-//
-// ErrDbUnknownType will be returned if the the database type is not registered.
-func Create(dbType string, args ...interface{}) (DB, error) {
-	drv, exists := drivers[dbType]
-	if !exists {
-		str := fmt.Sprintf("driver %q is not registered", dbType)
-		return nil, makeError(ErrDbUnknownType, str, nil)
-	}
-
-	return drv.Create(args...)
-}
-
-// Open opens an existing database for the specified type. The arguments are
-// specific to the database type driver. See the documentation for the database
-// driver for further details.
-//
-// ErrDbUnknownType will be returned if the the database type is not registered.
-func Open(dbType string, args ...interface{}) (DB, error) {
-	drv, exists := drivers[dbType]
-	if !exists {
-		str := fmt.Sprintf("driver %q is not registered", dbType)
-		return nil, makeError(ErrDbUnknownType, str, nil)
-	}
-
-	return drv.Open(args...)
-}

database/driver_test.go

@@ -1,128 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package database_test
-
-import (
-	"github.com/pkg/errors"
-	"testing"
-
-	"github.com/kaspanet/kaspad/database"
-	_ "github.com/kaspanet/kaspad/database/ffldb"
-)
-
-// checkDbError ensures the passed error is a database.Error with an error code
-// that matches the passed  error code.
-func checkDbError(t *testing.T, testName string, gotErr error, wantErrCode database.ErrorCode) bool {
-	dbErr, ok := gotErr.(database.Error)
-	if !ok {
-		t.Errorf("%s: unexpected error type - got %T, want %T",
-			testName, gotErr, database.Error{})
-		return false
-	}
-	if dbErr.ErrorCode != wantErrCode {
-		t.Errorf("%s: unexpected error code - got %s (%s), want %s",
-			testName, dbErr.ErrorCode, dbErr.Description,
-			wantErrCode)
-		return false
-	}
-
-	return true
-}
-
-// TestAddDuplicateDriver ensures that adding a duplicate driver does not
-// overwrite an existing one.
-func TestAddDuplicateDriver(t *testing.T) {
-	supportedDrivers := database.SupportedDrivers()
-	if len(supportedDrivers) == 0 {
-		t.Errorf("no backends to test")
-		return
-	}
-	dbType := supportedDrivers[0]
-
-	// bogusCreateDB is a function which acts as a bogus create and open
-	// driver function and intentionally returns a failure that can be
-	// detected if the interface allows a duplicate driver to overwrite an
-	// existing one.
-	bogusCreateDB := func(args ...interface{}) (database.DB, error) {
-		return nil, errors.Errorf("duplicate driver allowed for database "+
-			"type [%v]", dbType)
-	}
-
-	// Create a driver that tries to replace an existing one. Set its
-	// create and open functions to a function that causes a test failure if
-	// they are invoked.
-	driver := database.Driver{
-		DbType: dbType,
-		Create: bogusCreateDB,
-		Open:   bogusCreateDB,
-	}
-	testName := "duplicate driver registration"
-	err := database.RegisterDriver(driver)
-	if !checkDbError(t, testName, err, database.ErrDbTypeRegistered) {
-		return
-	}
-}
-
-// TestCreateOpenFail ensures that errors which occur while opening or closing
-// a database are handled properly.
-func TestCreateOpenFail(t *testing.T) {
-	// bogusCreateDB is a function which acts as a bogus create and open
-	// driver function that intentionally returns a failure which can be
-	// detected.
-	dbType := "createopenfail"
-	openError := errors.Errorf("failed to create or open database for "+
-		"database type [%v]", dbType)
-	bogusCreateDB := func(args ...interface{}) (database.DB, error) {
-		return nil, openError
-	}
-
-	// Create and add driver that intentionally fails when created or opened
-	// to ensure errors on database open and create are handled properly.
-	driver := database.Driver{
-		DbType: dbType,
-		Create: bogusCreateDB,
-		Open:   bogusCreateDB,
-	}
-	database.RegisterDriver(driver)
-
-	// Ensure creating a database with the new type fails with the expected
-	// error.
-	_, err := database.Create(dbType)
-	if err != openError {
-		t.Errorf("expected error not received - got: %v, want %v", err,
-			openError)
-		return
-	}
-
-	// Ensure opening a database with the new type fails with the expected
-	// error.
-	_, err = database.Open(dbType)
-	if err != openError {
-		t.Errorf("expected error not received - got: %v, want %v", err,
-			openError)
-		return
-	}
-}
-
-// TestCreateOpenUnsupported ensures that attempting to create or open an
-// unsupported database type is handled properly.
-func TestCreateOpenUnsupported(t *testing.T) {
-	// Ensure creating a database with an unsupported type fails with the
-	// expected error.
-	testName := "create with unsupported database type"
-	dbType := "unsupported"
-	_, err := database.Create(dbType)
-	if !checkDbError(t, testName, err, database.ErrDbUnknownType) {
-		return
-	}
-
-	// Ensure opening a database with the an unsupported type fails with the
-	// expected error.
-	testName = "open with unsupported database type"
-	_, err = database.Open(dbType)
-	if !checkDbError(t, testName, err, database.ErrDbUnknownType) {
-		return
-	}
-}

database/error.go

@@ -1,211 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package database
-
-import (
-	"fmt"
-	"github.com/pkg/errors"
-)
-
-// ErrorCode identifies a kind of error.
-type ErrorCode int
-
-// These constants are used to identify a specific database Error.
-const (
-	// **************************************
-	// Errors related to driver registration.
-	// **************************************
-
-	// ErrDbTypeRegistered indicates two different database drivers
-	// attempt to register with the name database type.
-	ErrDbTypeRegistered ErrorCode = iota
-
-	// *************************************
-	// Errors related to database functions.
-	// *************************************
-
-	// ErrDbUnknownType indicates there is no driver registered for
-	// the specified database type.
-	ErrDbUnknownType
-
-	// ErrDbDoesNotExist indicates open is called for a database that
-	// does not exist.
-	ErrDbDoesNotExist
-
-	// ErrDbExists indicates create is called for a database that
-	// already exists.
-	ErrDbExists
-
-	// ErrDbNotOpen indicates a database instance is accessed before
-	// it is opened or after it is closed.
-	ErrDbNotOpen
-
-	// ErrDbAlreadyOpen indicates open was called on a database that
-	// is already open.
-	ErrDbAlreadyOpen
-
-	// ErrInvalid indicates the specified database is not valid.
-	ErrInvalid
-
-	// ErrCorruption indicates a checksum failure occurred which invariably
-	// means the database is corrupt.
-	ErrCorruption
-
-	// ****************************************
-	// Errors related to database transactions.
-	// ****************************************
-
-	// ErrTxClosed indicates an attempt was made to commit or rollback a
-	// transaction that has already had one of those operations performed.
-	ErrTxClosed
-
-	// ErrTxNotWritable indicates an operation that requires write access to
-	// the database was attempted against a read-only transaction.
-	ErrTxNotWritable
-
-	// **************************************
-	// Errors related to metadata operations.
-	// **************************************
-
-	// ErrBucketNotFound indicates an attempt to access a bucket that has
-	// not been created yet.
-	ErrBucketNotFound
-
-	// ErrBucketExists indicates an attempt to create a bucket that already
-	// exists.
-	ErrBucketExists
-
-	// ErrBucketNameRequired indicates an attempt to create a bucket with a
-	// blank name.
-	ErrBucketNameRequired
-
-	// ErrKeyRequired indicates at attempt to insert a zero-length key.
-	ErrKeyRequired
-
-	// ErrKeyTooLarge indicates an attmempt to insert a key that is larger
-	// than the max allowed key size. The max key size depends on the
-	// specific backend driver being used. As a general rule, key sizes
-	// should be relatively, so this should rarely be an issue.
-	ErrKeyTooLarge
-
-	// ErrValueTooLarge indicates an attmpt to insert a value that is larger
-	// than max allowed value size. The max key size depends on the
-	// specific backend driver being used.
-	ErrValueTooLarge
-
-	// ErrIncompatibleValue indicates the value in question is invalid for
-	// the specific requested operation. For example, trying create or
-	// delete a bucket with an existing non-bucket key, attempting to create
-	// or delete a non-bucket key with an existing bucket key, or trying to
-	// delete a value via a cursor when it points to a nested bucket.
-	ErrIncompatibleValue
-
-	// ***************************************
-	// Errors related to block I/O operations.
-	// ***************************************
-
-	// ErrBlockNotFound indicates a block with the provided hash does not
-	// exist in the database.
-	ErrBlockNotFound
-
-	// ErrBlockExists indicates a block with the provided hash already
-	// exists in the database.
-	ErrBlockExists
-
-	// ErrBlockRegionInvalid indicates a region that exceeds the bounds of
-	// the specified block was requested. When the hash provided by the
-	// region does not correspond to an existing block, the error will be
-	// ErrBlockNotFound instead.
-	ErrBlockRegionInvalid
-
-	// ***********************************
-	// Support for driver-specific errors.
-	// ***********************************
-
-	// ErrDriverSpecific indicates the Err field is a driver-specific error.
-	// This provides a mechanism for drivers to plug-in their own custom
-	// errors for any situations which aren't already covered by the error
-	// codes provided by this package.
-	ErrDriverSpecific
-
-	// numErrorCodes is the maximum error code number used in tests.
-	numErrorCodes
-)
-
-// Map of ErrorCode values back to their constant names for pretty printing.
-var errorCodeStrings = map[ErrorCode]string{
-	ErrDbTypeRegistered:   "ErrDbTypeRegistered",
-	ErrDbUnknownType:      "ErrDbUnknownType",
-	ErrDbDoesNotExist:     "ErrDbDoesNotExist",
-	ErrDbExists:           "ErrDbExists",
-	ErrDbNotOpen:          "ErrDbNotOpen",
-	ErrDbAlreadyOpen:      "ErrDbAlreadyOpen",
-	ErrInvalid:            "ErrInvalid",
-	ErrCorruption:         "ErrCorruption",
-	ErrTxClosed:           "ErrTxClosed",
-	ErrTxNotWritable:      "ErrTxNotWritable",
-	ErrBucketNotFound:     "ErrBucketNotFound",
-	ErrBucketExists:       "ErrBucketExists",
-	ErrBucketNameRequired: "ErrBucketNameRequired",
-	ErrKeyRequired:        "ErrKeyRequired",
-	ErrKeyTooLarge:        "ErrKeyTooLarge",
-	ErrValueTooLarge:      "ErrValueTooLarge",
-	ErrIncompatibleValue:  "ErrIncompatibleValue",
-	ErrBlockNotFound:      "ErrBlockNotFound",
-	ErrBlockExists:        "ErrBlockExists",
-	ErrBlockRegionInvalid: "ErrBlockRegionInvalid",
-	ErrDriverSpecific:     "ErrDriverSpecific",
-}
-
-// String returns the ErrorCode as a human-readable name.
-func (e ErrorCode) String() string {
-	if s := errorCodeStrings[e]; s != "" {
-		return s
-	}
-	return fmt.Sprintf("Unknown ErrorCode (%d)", int(e))
-}
-
-// Error provides a single type for errors that can happen during database
-// operation. It is used to indicate several types of failures including errors
-// with caller requests such as specifying invalid block regions or attempting
-// to access data against closed database transactions, driver errors, errors
-// retrieving data, and errors communicating with database servers.
-//
-// The caller can use type assertions to determine if an error is an Error and
-// access the ErrorCode field to ascertain the specific reason for the failure.
-//
-// The ErrDriverSpecific error code will also have the Err field set with the
-// underlying error. Depending on the backend driver, the Err field might be
-// set to the underlying error for other error codes as well.
-type Error struct {
-	ErrorCode   ErrorCode // Describes the kind of error
-	Description string    // Human readable description of the issue
-	Err         error     // Underlying error
-}
-
-// Error satisfies the error interface and prints human-readable errors.
-func (e Error) Error() string {
-	if e.Err != nil {
-		return e.Description + ": " + e.Err.Error()
-	}
-	return e.Description
-}
-
-// makeError creates an Error given a set of arguments. The error code must
-// be one of the error codes provided by this package.
-func makeError(c ErrorCode, desc string, err error) Error {
-	return Error{ErrorCode: c, Description: desc, Err: err}
-}
-
-// IsErrorCode returns whether or not the provided error is a script error with
-// the provided error code.
-func IsErrorCode(err error, c ErrorCode) bool {
-	var errError Error
-	if ok := errors.As(err, &errError); ok {
-		return errError.ErrorCode == c
-	}
-
-	return false
-}

database/error_test.go

@@ -1,118 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package database
-
-import (
-	"github.com/pkg/errors"
-	"testing"
-)
-
-// TestErrorCodeStringer tests the stringized output for the ErrorCode type.
-func TestErrorCodeStringer(t *testing.T) {
-	tests := []struct {
-		in   ErrorCode
-		want string
-	}{
-		{ErrDbTypeRegistered, "ErrDbTypeRegistered"},
-		{ErrDbUnknownType, "ErrDbUnknownType"},
-		{ErrDbDoesNotExist, "ErrDbDoesNotExist"},
-		{ErrDbExists, "ErrDbExists"},
-		{ErrDbNotOpen, "ErrDbNotOpen"},
-		{ErrDbAlreadyOpen, "ErrDbAlreadyOpen"},
-		{ErrInvalid, "ErrInvalid"},
-		{ErrCorruption, "ErrCorruption"},
-		{ErrTxClosed, "ErrTxClosed"},
-		{ErrTxNotWritable, "ErrTxNotWritable"},
-		{ErrBucketNotFound, "ErrBucketNotFound"},
-		{ErrBucketExists, "ErrBucketExists"},
-		{ErrBucketNameRequired, "ErrBucketNameRequired"},
-		{ErrKeyRequired, "ErrKeyRequired"},
-		{ErrKeyTooLarge, "ErrKeyTooLarge"},
-		{ErrValueTooLarge, "ErrValueTooLarge"},
-		{ErrIncompatibleValue, "ErrIncompatibleValue"},
-		{ErrBlockNotFound, "ErrBlockNotFound"},
-		{ErrBlockExists, "ErrBlockExists"},
-		{ErrBlockRegionInvalid, "ErrBlockRegionInvalid"},
-		{ErrDriverSpecific, "ErrDriverSpecific"},
-
-		{0xffff, "Unknown ErrorCode (65535)"},
-	}
-
-	// Detect additional error codes that don't have the stringer added.
-	if len(tests)-1 != int(TstNumErrorCodes) {
-		t.Errorf("It appears an error code was added without adding " +
-			"an associated stringer test")
-	}
-
-	t.Logf("Running %d tests", len(tests))
-	for i, test := range tests {
-		result := test.in.String()
-		if result != test.want {
-			t.Errorf("String #%d\ngot: %s\nwant: %s", i, result,
-				test.want)
-			continue
-		}
-	}
-}
-
-// TestError tests the error output for the Error type.
-func TestError(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		in   Error
-		want string
-	}{
-		{
-			Error{Description: "some error"},
-			"some error",
-		},
-		{
-			Error{Description: "human-readable error"},
-			"human-readable error",
-		},
-		{
-			Error{
-				ErrorCode:   ErrDriverSpecific,
-				Description: "some error",
-				Err:         errors.New("driver-specific error"),
-			},
-			"some error: driver-specific error",
-		},
-	}
-
-	t.Logf("Running %d tests", len(tests))
-	for i, test := range tests {
-		result := test.in.Error()
-		if result != test.want {
-			t.Errorf("Error #%d\n got: %s want: %s", i, result,
-				test.want)
-			continue
-		}
-	}
-}
-
-func TestIsErrorCode(t *testing.T) {
-	dummyError := errors.New("")
-
-	tests := []struct {
-		err            error
-		code           ErrorCode
-		expectedResult bool
-	}{
-		{makeError(ErrBucketExists, "", dummyError), ErrBucketExists, true},
-		{makeError(ErrBucketExists, "", dummyError), ErrBlockExists, false},
-		{dummyError, ErrBlockExists, false},
-		{nil, ErrBlockExists, false},
-	}
-
-	for i, test := range tests {
-		actualResult := IsErrorCode(test.err, test.code)
-		if test.expectedResult != actualResult {
-			t.Errorf("TestIsErrorCode: %d: Expected: %t, but got: %t",
-				i, test.expectedResult, actualResult)
-		}
-	}
-}

database/errors.go

@@ -0,0 +1,12 @@
+package database
+
+import "errors"
+
+// ErrNotFound denotes that the requested item was not
+// found in the database.
+var ErrNotFound = errors.New("not found")
+
+// IsNotFoundError checks whether an error is an ErrNotFound.
+func IsNotFoundError(err error) bool {
+	return errors.Is(err, ErrNotFound)
+}

database/example_test.go

@@ -1,180 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package database_test
-
-import (
-	"bytes"
-	"fmt"
-	"github.com/pkg/errors"
-	"os"
-	"path/filepath"
-
-	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
-	_ "github.com/kaspanet/kaspad/database/ffldb"
-	"github.com/kaspanet/kaspad/util"
-	"github.com/kaspanet/kaspad/wire"
-)
-
-// This example demonstrates creating a new database.
-func ExampleCreate() {
-	// This example assumes the ffldb driver is imported.
-	//
-	// import (
-	// 	"github.com/kaspanet/kaspad/database"
-	// 	_ "github.com/kaspanet/kaspad/database/ffldb"
-	// )
-
-	// Create a database and schedule it to be closed and removed on exit.
-	// Typically you wouldn't want to remove the database right away like
-	// this, nor put it in the temp directory, but it's done here to ensure
-	// the example cleans up after itself.
-	dbPath := filepath.Join(os.TempDir(), "examplecreate")
-	db, err := database.Create("ffldb", dbPath, wire.Mainnet)
-	if err != nil {
-		fmt.Println(err)
-		return
-	}
-	defer os.RemoveAll(dbPath)
-	defer db.Close()
-
-	// Output:
-}
-
-// This example demonstrates creating a new database and using a managed
-// read-write transaction to store and retrieve metadata.
-func Example_basicUsage() {
-	// This example assumes the ffldb driver is imported.
-	//
-	// import (
-	// 	"github.com/kaspanet/kaspad/database"
-	// 	_ "github.com/kaspanet/kaspad/database/ffldb"
-	// )
-
-	// Create a database and schedule it to be closed and removed on exit.
-	// Typically you wouldn't want to remove the database right away like
-	// this, nor put it in the temp directory, but it's done here to ensure
-	// the example cleans up after itself.
-	dbPath := filepath.Join(os.TempDir(), "exampleusage")
-	// ensure that DB does not exist before test starts
-	os.RemoveAll(dbPath)
-	db, err := database.Create("ffldb", dbPath, wire.Mainnet)
-	if err != nil {
-		fmt.Println(err)
-		return
-	}
-	defer os.RemoveAll(dbPath)
-	defer db.Close()
-
-	// Use the Update function of the database to perform a managed
-	// read-write transaction. The transaction will automatically be rolled
-	// back if the supplied inner function returns a non-nil error.
-	err = db.Update(func(dbTx database.Tx) error {
-		// Store a key/value pair directly in the metadata bucket.
-		// Typically a nested bucket would be used for a given feature,
-		// but this example is using the metadata bucket directly for
-		// simplicity.
-		key := []byte("mykey")
-		value := []byte("myvalue")
-		if err := dbTx.Metadata().Put(key, value); err != nil {
-			return err
-		}
-
-		// Read the key back and ensure it matches.
-		if !bytes.Equal(dbTx.Metadata().Get(key), value) {
-			return errors.Errorf("unexpected value for key '%s'", key)
-		}
-
-		// Create a new nested bucket under the metadata bucket.
-		nestedBucketKey := []byte("mybucket")
-		nestedBucket, err := dbTx.Metadata().CreateBucket(nestedBucketKey)
-		if err != nil {
-			return err
-		}
-
-		// The key from above that was set in the metadata bucket does
-		// not exist in this new nested bucket.
-		if nestedBucket.Get(key) != nil {
-			return errors.Errorf("key '%s' is not expected nil", key)
-		}
-
-		return nil
-	})
-	if err != nil {
-		fmt.Println(err)
-		return
-	}
-
-	// Output:
-}
-
-// This example demonstrates creating a new database, using a managed read-write
-// transaction to store a block, and using a managed read-only transaction to
-// fetch the block.
-func Example_blockStorageAndRetrieval() {
-	// This example assumes the ffldb driver is imported.
-	//
-	// import (
-	// 	"github.com/kaspanet/kaspad/database"
-	// 	_ "github.com/kaspanet/kaspad/database/ffldb"
-	// )
-
-	// Create a database and schedule it to be closed and removed on exit.
-	// Typically you wouldn't want to remove the database right away like
-	// this, nor put it in the temp directory, but it's done here to ensure
-	// the example cleans up after itself.
-	dbPath := filepath.Join(os.TempDir(), "exampleblkstorage")
-	db, err := database.Create("ffldb", dbPath, wire.Mainnet)
-	if err != nil {
-		fmt.Println(err)
-		return
-	}
-	defer os.RemoveAll(dbPath)
-	defer db.Close()
-
-	// Use the Update function of the database to perform a managed
-	// read-write transaction and store a genesis block in the database as
-	// and example.
-	err = db.Update(func(dbTx database.Tx) error {
-		genesisBlock := dagconfig.MainnetParams.GenesisBlock
-		return dbTx.StoreBlock(util.NewBlock(genesisBlock))
-	})
-	if err != nil {
-		fmt.Println(err)
-		return
-	}
-
-	// Use the View function of the database to perform a managed read-only
-	// transaction and fetch the block stored above.
-	var loadedBlockBytes []byte
-	err = db.Update(func(dbTx database.Tx) error {
-		genesisHash := dagconfig.MainnetParams.GenesisHash
-		blockBytes, err := dbTx.FetchBlock(genesisHash)
-		if err != nil {
-			return err
-		}
-
-		// As documented, all data fetched from the database is only
-		// valid during a database transaction in order to support
-		// zero-copy backends. Thus, make a copy of the data so it
-		// can be used outside of the transaction.
-		loadedBlockBytes = make([]byte, len(blockBytes))
-		copy(loadedBlockBytes, blockBytes)
-		return nil
-	})
-	if err != nil {
-		fmt.Println(err)
-		return
-	}
-
-	// Typically at this point, the block could be deserialized via the
-	// wire.MsgBlock.Deserialize function or used in its serialized form
-	// depending on need. However, for this example, just display the
-	// number of serialized bytes to show it was loaded as expected.
-	fmt.Printf("Serialized block size: %d bytes\n", len(loadedBlockBytes))
-
-	// Output:
-	// Serialized block size: 280 bytes
-}

database/export_test.go

@@ -1,17 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-/*
-This test file is part of the database package rather than than the
-database_test package so it can bridge access to the internals to properly test
-cases which are either not possible or can't reliably be tested via the public
-interface. The functions, constants, and variables are only exported while the
-tests are being run.
-*/
-
-package database
-
-// TstNumErrorCodes makes the internal numErrorCodes parameter available to the
-// test package.
-const TstNumErrorCodes = numErrorCodes

database/ffldb/README.md

@@ -1,34 +0,0 @@
-ffldb
-=====
-
-[![ISC License](http://img.shields.io/badge/license-ISC-blue.svg)](https://choosealicense.com/licenses/isc/)
-[![GoDoc](https://godoc.org/github.com/kaspanet/kaspad/database/ffldb?status.png)](http://godoc.org/github.com/kaspanet/kaspad/database/ffldb)
-=======
-
-Package ffldb implements a driver for the database package that uses leveldb for
-the backing metadata and flat files for block storage.
-
-This driver is the recommended driver for use with kaspad. It makes use of leveldb
-for the metadata, flat files for block storage, and checksums in key areas to
-ensure data integrity.
-
-## Usage
-
-This package is a driver to the database package and provides the database type
-of "ffldb". The parameters the Open and Create functions take are the
-database path as a string and the block network.
-
-```Go
-db, err := database.Open("ffldb", "path/to/database", wire.Mainnet)
-if err != nil {
-	// Handle error
-}
-```
-
-```Go
-db, err := database.Create("ffldb", "path/to/database", wire.Mainnet)
-if err != nil {
-	// Handle error
-}
-```
-

database/ffldb/bench_test.go

@@ -1,97 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package ffldb
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-
-	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/util"
-)
-
-// BenchmarkBlockHeader benchmarks how long it takes to load the mainnet genesis
-// block header.
-func BenchmarkBlockHeader(b *testing.B) {
-	// Start by creating a new database and populating it with the mainnet
-	// genesis block.
-	dbPath := filepath.Join(os.TempDir(), "ffldb-benchblkhdr")
-	_ = os.RemoveAll(dbPath)
-	db, err := database.Create("ffldb", dbPath, blockDataNet)
-	if err != nil {
-		b.Fatal(err)
-	}
-	defer os.RemoveAll(dbPath)
-	defer db.Close()
-	err = db.Update(func(dbTx database.Tx) error {
-		block := util.NewBlock(dagconfig.MainnetParams.GenesisBlock)
-		return dbTx.StoreBlock(block)
-	})
-	if err != nil {
-		b.Fatal(err)
-	}
-
-	b.ReportAllocs()
-	b.ResetTimer()
-	err = db.View(func(dbTx database.Tx) error {
-		blockHash := dagconfig.MainnetParams.GenesisHash
-		for i := 0; i < b.N; i++ {
-			_, err := dbTx.FetchBlockHeader(blockHash)
-			if err != nil {
-				return err
-			}
-		}
-		return nil
-	})
-	if err != nil {
-		b.Fatal(err)
-	}
-
-	// Don't benchmark teardown.
-	b.StopTimer()
-}
-
-// BenchmarkBlockHeader benchmarks how long it takes to load the mainnet genesis
-// block.
-func BenchmarkBlock(b *testing.B) {
-	// Start by creating a new database and populating it with the mainnet
-	// genesis block.
-	dbPath := filepath.Join(os.TempDir(), "ffldb-benchblk")
-	_ = os.RemoveAll(dbPath)
-	db, err := database.Create("ffldb", dbPath, blockDataNet)
-	if err != nil {
-		b.Fatal(err)
-	}
-	defer os.RemoveAll(dbPath)
-	defer db.Close()
-	err = db.Update(func(dbTx database.Tx) error {
-		block := util.NewBlock(dagconfig.MainnetParams.GenesisBlock)
-		return dbTx.StoreBlock(block)
-	})
-	if err != nil {
-		b.Fatal(err)
-	}
-
-	b.ReportAllocs()
-	b.ResetTimer()
-	err = db.View(func(dbTx database.Tx) error {
-		blockHash := dagconfig.MainnetParams.GenesisHash
-		for i := 0; i < b.N; i++ {
-			_, err := dbTx.FetchBlock(blockHash)
-			if err != nil {
-				return err
-			}
-		}
-		return nil
-	})
-	if err != nil {
-		b.Fatal(err)
-	}
-
-	// Don't benchmark teardown.
-	b.StopTimer()
-}

database/ffldb/blockio.go

@@ -1,765 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-// This file contains the implementation functions for reading, writing, and
-// otherwise working with the flat files that house the actual blocks.
-
-package ffldb
-
-import (
-	"container/list"
-	"encoding/binary"
-	"fmt"
-	"github.com/pkg/errors"
-	"hash/crc32"
-	"io"
-	"os"
-	"path/filepath"
-	"sync"
-	"syscall"
-
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/util/daghash"
-	"github.com/kaspanet/kaspad/wire"
-)
-
-const (
-	// maxOpenFiles is the max number of open files to maintain in the
-	// open blocks cache. Note that this does not include the current
-	// write file, so there will typically be one more than this value open.
-	maxOpenFiles = 25
-
-	// maxBlockFileSize is the maximum size for each file used to store
-	// blocks.
-	//
-	// NOTE: The current code uses uint32 for all offsets, so this value
-	// must be less than 2^32 (4 GiB). This is also why it's a typed
-	// constant.
-	maxBlockFileSize uint32 = 512 * 1024 * 1024 // 512 MiB
-)
-
-var (
-	// castagnoli houses the Catagnoli polynomial used for CRC-32 checksums.
-	castagnoli = crc32.MakeTable(crc32.Castagnoli)
-)
-
-// filer is an interface which acts very similar to a *os.File and is typically
-// implemented by it. It exists so the test code can provide mock files for
-// properly testing corruption and file system issues.
-type filer interface {
-	io.Closer
-	io.WriterAt
-	io.ReaderAt
-	Truncate(size int64) error
-	Sync() error
-}
-
-// lockableFile represents a block file on disk that has been opened for either
-// read or read/write access. It also contains a read-write mutex to support
-// multiple concurrent readers.
-type lockableFile struct {
-	sync.RWMutex
-	file filer
-}
-
-// writeCursor represents the current file and offset of the block file on disk
-// for performing all writes. It also contains a read-write mutex to support
-// multiple concurrent readers which can reuse the file handle.
-type writeCursor struct {
-	sync.RWMutex
-
-	// curFile is the current block file that will be appended to when
-	// writing new blocks.
-	curFile *lockableFile
-
-	// curFileNum is the current block file number and is used to allow
-	// readers to use the same open file handle.
-	curFileNum uint32
-
-	// curOffset is the offset in the current write block file where the
-	// next new block will be written.
-	curOffset uint32
-}
-
-// blockStore houses information used to handle reading and writing blocks (and
-// part of blocks) into flat files with support for multiple concurrent readers.
-type blockStore struct {
-	// network is the specific network to use in the flat files for each
-	// block.
-	network wire.KaspaNet
-
-	// basePath is the base path used for the flat block files and metadata.
-	basePath string
-
-	// maxBlockFileSize is the maximum size for each file used to store
-	// blocks. It is defined on the store so the whitebox tests can
-	// override the value.
-	maxBlockFileSize uint32
-
-	// maxOpenFiles is the max number of open files to maintain in the
-	// open blocks cache. Note that this does not include the current
-	// write file, so there will typically be one more than this value open.
-	// It is defined on the store so the whitebox tests can override the value.
-	maxOpenFiles int
-
-	// The following fields are related to the flat files which hold the
-	// actual blocks. The number of open files is limited by maxOpenFiles.
-	//
-	// obfMutex protects concurrent access to the openBlockFiles map. It is
-	// a RWMutex so multiple readers can simultaneously access open files.
-	//
-	// openBlockFiles houses the open file handles for existing block files
-	// which have been opened read-only along with an individual RWMutex.
-	// This scheme allows multiple concurrent readers to the same file while
-	// preventing the file from being closed out from under them.
-	//
-	// lruMutex protects concurrent access to the least recently used list
-	// and lookup map.
-	//
-	// openBlocksLRU tracks how the open files are refenced by pushing the
-	// most recently used files to the front of the list thereby trickling
-	// the least recently used files to end of the list. When a file needs
-	// to be closed due to exceeding the the max number of allowed open
-	// files, the one at the end of the list is closed.
-	//
-	// fileNumToLRUElem is a mapping between a specific block file number
-	// and the associated list element on the least recently used list.
-	//
-	// Thus, with the combination of these fields, the database supports
-	// concurrent non-blocking reads across multiple and individual files
-	// along with intelligently limiting the number of open file handles by
-	// closing the least recently used files as needed.
-	//
-	// NOTE: The locking order used throughout is well-defined and MUST be
-	// followed. Failure to do so could lead to deadlocks. In particular,
-	// the locking order is as follows:
-	//   1) obfMutex
-	//   2) lruMutex
-	//   3) writeCursor mutex
-	//   4) specific file mutexes
-	//
-	// None of the mutexes are required to be locked at the same time, and
-	// often aren't. However, if they are to be locked simultaneously, they
-	// MUST be locked in the order previously specified.
-	//
-	// Due to the high performance and multi-read concurrency requirements,
-	// write locks should only be held for the minimum time necessary.
-	obfMutex         sync.RWMutex
-	lruMutex         sync.Mutex
-	openBlocksLRU    *list.List // Contains uint32 block file numbers.
-	fileNumToLRUElem map[uint32]*list.Element
-	openBlockFiles   map[uint32]*lockableFile
-
-	// writeCursor houses the state for the current file and location that
-	// new blocks are written to.
-	writeCursor *writeCursor
-
-	// These functions are set to openFile, openWriteFile, and deleteFile by
-	// default, but are exposed here to allow the whitebox tests to replace
-	// them when working with mock files.
-	openFileFunc      func(fileNum uint32) (*lockableFile, error)
-	openWriteFileFunc func(fileNum uint32) (filer, error)
-	deleteFileFunc    func(fileNum uint32) error
-}
-
-// blockLocation identifies a particular block file and location.
-type blockLocation struct {
-	blockFileNum uint32
-	fileOffset   uint32
-	blockLen     uint32
-}
-
-// deserializeBlockLoc deserializes the passed serialized block location
-// information. This is data stored into the block index metadata for each
-// block. The serialized data passed to this function MUST be at least
-// blockLocSize bytes or it will panic. The error check is avoided here because
-// this information will always be coming from the block index which includes a
-// checksum to detect corruption. Thus it is safe to use this unchecked here.
-func deserializeBlockLoc(serializedLoc []byte) blockLocation {
-	// The serialized block location format is:
-	//
-	//  [0:4]  Block file (4 bytes)
-	//  [4:8]  File offset (4 bytes)
-	//  [8:12] Block length (4 bytes)
-	return blockLocation{
-		blockFileNum: byteOrder.Uint32(serializedLoc[0:4]),
-		fileOffset:   byteOrder.Uint32(serializedLoc[4:8]),
-		blockLen:     byteOrder.Uint32(serializedLoc[8:12]),
-	}
-}
-
-// serializeBlockLoc returns the serialization of the passed block location.
-// This is data to be stored into the block index metadata for each block.
-func serializeBlockLoc(loc blockLocation) []byte {
-	// The serialized block location format is:
-	//
-	//  [0:4]  Block file (4 bytes)
-	//  [4:8]  File offset (4 bytes)
-	//  [8:12] Block length (4 bytes)
-	var serializedData [12]byte
-	byteOrder.PutUint32(serializedData[0:4], loc.blockFileNum)
-	byteOrder.PutUint32(serializedData[4:8], loc.fileOffset)
-	byteOrder.PutUint32(serializedData[8:12], loc.blockLen)
-	return serializedData[:]
-}
-
-// blockFilePath return the file path for the provided block file number.
-func blockFilePath(dbPath string, fileNum uint32) string {
-	// Choose 9 digits of precision for the filenames. 9 digits provide
-	// 10^9 files @ 512MiB each a total of ~476.84PiB.
-
-	fileName := fmt.Sprintf("%09d.fdb", fileNum)
-	return filepath.Join(dbPath, fileName)
-}
-
-// openWriteFile returns a file handle for the passed flat file number in
-// read/write mode. The file will be created if needed. It is typically used
-// for the current file that will have all new data appended. Unlike openFile,
-// this function does not keep track of the open file and it is not subject to
-// the maxOpenFiles limit.
-func (s *blockStore) openWriteFile(fileNum uint32) (filer, error) {
-	// The current block file needs to be read-write so it is possible to
-	// append to it. Also, it shouldn't be part of the least recently used
-	// file.
-	filePath := blockFilePath(s.basePath, fileNum)
-	file, err := os.OpenFile(filePath, os.O_RDWR|os.O_CREATE, 0666)
-	if err != nil {
-		str := fmt.Sprintf("failed to open file %q: %s", filePath, err)
-		return nil, makeDbErr(database.ErrDriverSpecific, str, err)
-	}
-
-	return file, nil
-}
-
-// openFile returns a read-only file handle for the passed flat file number.
-// The function also keeps track of the open files, performs least recently
-// used tracking, and limits the number of open files to maxOpenFiles by closing
-// the least recently used file as needed.
-//
-// This function MUST be called with the overall files mutex (s.obfMutex) locked
-// for WRITES.
-func (s *blockStore) openFile(fileNum uint32) (*lockableFile, error) {
-	// Open the appropriate file as read-only.
-	filePath := blockFilePath(s.basePath, fileNum)
-	file, err := os.Open(filePath)
-	if err != nil {
-		return nil, makeDbErr(database.ErrDriverSpecific, err.Error(),
-			err)
-	}
-	blockFile := &lockableFile{file: file}
-
-	// Close the least recently used file if the file exceeds the max
-	// allowed open files. This is not done until after the file open in
-	// case the file fails to open, there is no need to close any files.
-	//
-	// A write lock is required on the LRU list here to protect against
-	// modifications happening as already open files are read from and
-	// shuffled to the front of the list.
-	//
-	// Also, add the file that was just opened to the front of the least
-	// recently used list to indicate it is the most recently used file and
-	// therefore should be closed last.
-	s.lruMutex.Lock()
-	lruList := s.openBlocksLRU
-	if lruList.Len() >= s.maxOpenFiles {
-		lruFileNum := lruList.Remove(lruList.Back()).(uint32)
-		oldBlockFile := s.openBlockFiles[lruFileNum]
-
-		// Close the old file under the write lock for the file in case
-		// any readers are currently reading from it so it's not closed
-		// out from under them.
-		oldBlockFile.Lock()
-		_ = oldBlockFile.file.Close()
-		oldBlockFile.Unlock()
-
-		delete(s.openBlockFiles, lruFileNum)
-		delete(s.fileNumToLRUElem, lruFileNum)
-	}
-	s.fileNumToLRUElem[fileNum] = lruList.PushFront(fileNum)
-	s.lruMutex.Unlock()
-
-	// Store a reference to it in the open block files map.
-	s.openBlockFiles[fileNum] = blockFile
-
-	return blockFile, nil
-}
-
-// deleteFile removes the block file for the passed flat file number. The file
-// must already be closed and it is the responsibility of the caller to do any
-// other state cleanup necessary.
-func (s *blockStore) deleteFile(fileNum uint32) error {
-	filePath := blockFilePath(s.basePath, fileNum)
-	if err := os.Remove(filePath); err != nil {
-		return makeDbErr(database.ErrDriverSpecific, err.Error(), err)
-	}
-
-	return nil
-}
-
-// blockFile attempts to return an existing file handle for the passed flat file
-// number if it is already open as well as marking it as most recently used. It
-// will also open the file when it's not already open subject to the rules
-// described in openFile.
-//
-// NOTE: The returned block file will already have the read lock acquired and
-// the caller MUST call .RUnlock() to release it once it has finished all read
-// operations. This is necessary because otherwise it would be possible for a
-// separate goroutine to close the file after it is returned from here, but
-// before the caller has acquired a read lock.
-func (s *blockStore) blockFile(fileNum uint32) (*lockableFile, error) {
-	// When the requested block file is open for writes, return it.
-	wc := s.writeCursor
-	wc.RLock()
-	if fileNum == wc.curFileNum && wc.curFile.file != nil {
-		obf := wc.curFile
-		obf.RLock()
-		wc.RUnlock()
-		return obf, nil
-	}
-	wc.RUnlock()
-
-	// Try to return an open file under the overall files read lock.
-	s.obfMutex.RLock()
-	if obf, ok := s.openBlockFiles[fileNum]; ok {
-		s.lruMutex.Lock()
-		s.openBlocksLRU.MoveToFront(s.fileNumToLRUElem[fileNum])
-		s.lruMutex.Unlock()
-
-		obf.RLock()
-		s.obfMutex.RUnlock()
-		return obf, nil
-	}
-	s.obfMutex.RUnlock()
-
-	// Since the file isn't open already, need to check the open block files
-	// map again under write lock in case multiple readers got here and a
-	// separate one is already opening the file.
-	s.obfMutex.Lock()
-	if obf, ok := s.openBlockFiles[fileNum]; ok {
-		obf.RLock()
-		s.obfMutex.Unlock()
-		return obf, nil
-	}
-
-	// The file isn't open, so open it while potentially closing the least
-	// recently used one as needed.
-	obf, err := s.openFileFunc(fileNum)
-	if err != nil {
-		s.obfMutex.Unlock()
-		return nil, err
-	}
-	obf.RLock()
-	s.obfMutex.Unlock()
-	return obf, nil
-}
-
-// writeData is a helper function for writeBlock which writes the provided data
-// at the current write offset and updates the write cursor accordingly. The
-// field name parameter is only used when there is an error to provide a nicer
-// error message.
-//
-// The write cursor will be advanced the number of bytes actually written in the
-// event of failure.
-//
-// NOTE: This function MUST be called with the write cursor current file lock
-// held and must only be called during a write transaction so it is effectively
-// locked for writes. Also, the write cursor current file must NOT be nil.
-func (s *blockStore) writeData(data []byte, fieldName string) error {
-	wc := s.writeCursor
-	n, err := wc.curFile.file.WriteAt(data, int64(wc.curOffset))
-	wc.curOffset += uint32(n)
-	if err != nil {
-		var pathErr *os.PathError
-		if ok := errors.As(err, &pathErr); ok && pathErr.Err == syscall.ENOSPC {
-			log.Errorf("No space left on the hard disk, exiting...")
-			os.Exit(1)
-		}
-		str := fmt.Sprintf("failed to write %s to file %d at "+
-			"offset %d: %s", fieldName, wc.curFileNum,
-			wc.curOffset-uint32(n), err)
-		return makeDbErr(database.ErrDriverSpecific, str, err)
-	}
-
-	return nil
-}
-
-// writeBlock appends the specified raw block bytes to the store's write cursor
-// location and increments it accordingly. When the block would exceed the max
-// file size for the current flat file, this function will close the current
-// file, create the next file, update the write cursor, and write the block to
-// the new file.
-//
-// The write cursor will also be advanced the number of bytes actually written
-// in the event of failure.
-//
-// Format: <network><block length><serialized block><checksum>
-func (s *blockStore) writeBlock(rawBlock []byte) (blockLocation, error) {
-	// Compute how many bytes will be written.
-	// 4 bytes each for block network + 4 bytes for block length +
-	// length of raw block + 4 bytes for checksum.
-	blockLen := uint32(len(rawBlock))
-	fullLen := blockLen + 12
-
-	// Move to the next block file if adding the new block would exceed the
-	// max allowed size for the current block file. Also detect overflow
-	// to be paranoid, even though it isn't possible currently, numbers
-	// might change in the future to make it possible.
-	//
-	// NOTE: The writeCursor.offset field isn't protected by the mutex
-	// since it's only read/changed during this function which can only be
-	// called during a write transaction, of which there can be only one at
-	// a time.
-	wc := s.writeCursor
-	finalOffset := wc.curOffset + fullLen
-	if finalOffset < wc.curOffset || finalOffset > s.maxBlockFileSize {
-		// This is done under the write cursor lock since the curFileNum
-		// field is accessed elsewhere by readers.
-		//
-		// Close the current write file to force a read-only reopen
-		// with LRU tracking. The close is done under the write lock
-		// for the file to prevent it from being closed out from under
-		// any readers currently reading from it.
-		wc.Lock()
-		wc.curFile.Lock()
-		if wc.curFile.file != nil {
-			_ = wc.curFile.file.Close()
-			wc.curFile.file = nil
-		}
-		wc.curFile.Unlock()
-
-		// Start writes into next file.
-		wc.curFileNum++
-		wc.curOffset = 0
-		wc.Unlock()
-	}
-
-	// All writes are done under the write lock for the file to ensure any
-	// readers are finished and blocked first.
-	wc.curFile.Lock()
-	defer wc.curFile.Unlock()
-
-	// Open the current file if needed. This will typically only be the
-	// case when moving to the next file to write to or on initial database
-	// load. However, it might also be the case if rollbacks happened after
-	// file writes started during a transaction commit.
-	if wc.curFile.file == nil {
-		file, err := s.openWriteFileFunc(wc.curFileNum)
-		if err != nil {
-			return blockLocation{}, err
-		}
-		wc.curFile.file = file
-	}
-
-	// Kaspa network.
-	origOffset := wc.curOffset
-	hasher := crc32.New(castagnoli)
-	var scratch [4]byte
-	byteOrder.PutUint32(scratch[:], uint32(s.network))
-	if err := s.writeData(scratch[:], "network"); err != nil {
-		return blockLocation{}, err
-	}
-	_, _ = hasher.Write(scratch[:])
-
-	// Block length.
-	byteOrder.PutUint32(scratch[:], blockLen)
-	if err := s.writeData(scratch[:], "block length"); err != nil {
-		return blockLocation{}, err
-	}
-	_, _ = hasher.Write(scratch[:])
-
-	// Serialized block.
-	if err := s.writeData(rawBlock[:], "block"); err != nil {
-		return blockLocation{}, err
-	}
-	_, _ = hasher.Write(rawBlock)
-
-	// Castagnoli CRC-32 as a checksum of all the previous.
-	if err := s.writeData(hasher.Sum(nil), "checksum"); err != nil {
-		return blockLocation{}, err
-	}
-
-	loc := blockLocation{
-		blockFileNum: wc.curFileNum,
-		fileOffset:   origOffset,
-		blockLen:     fullLen,
-	}
-	return loc, nil
-}
-
-// readBlock reads the specified block record and returns the serialized block.
-// It ensures the integrity of the block data by checking that the serialized
-// network matches the current network associated with the block store and
-// comparing the calculated checksum against the one stored in the flat file.
-// This function also automatically handles all file management such as opening
-// and closing files as necessary to stay within the maximum allowed open files
-// limit.
-//
-// Returns ErrDriverSpecific if the data fails to read for any reason and
-// ErrCorruption if the checksum of the read data doesn't match the checksum
-// read from the file.
-//
-// Format: <network><block length><serialized block><checksum>
-func (s *blockStore) readBlock(hash *daghash.Hash, loc blockLocation) ([]byte, error) {
-	// Get the referenced block file handle opening the file as needed. The
-	// function also handles closing files as needed to avoid going over the
-	// max allowed open files.
-	blockFile, err := s.blockFile(loc.blockFileNum)
-	if err != nil {
-		return nil, err
-	}
-
-	serializedData := make([]byte, loc.blockLen)
-	n, err := blockFile.file.ReadAt(serializedData, int64(loc.fileOffset))
-	blockFile.RUnlock()
-	if err != nil {
-		str := fmt.Sprintf("failed to read block %s from file %d, "+
-			"offset %d: %s", hash, loc.blockFileNum, loc.fileOffset,
-			err)
-		return nil, makeDbErr(database.ErrDriverSpecific, str, err)
-	}
-
-	// Calculate the checksum of the read data and ensure it matches the
-	// serialized checksum. This will detect any data corruption in the
-	// flat file without having to do much more expensive merkle root
-	// calculations on the loaded block.
-	serializedChecksum := binary.BigEndian.Uint32(serializedData[n-4:])
-	calculatedChecksum := crc32.Checksum(serializedData[:n-4], castagnoli)
-	if serializedChecksum != calculatedChecksum {
-		str := fmt.Sprintf("block data for block %s checksum "+
-			"does not match - got %x, want %x", hash,
-			calculatedChecksum, serializedChecksum)
-		return nil, makeDbErr(database.ErrCorruption, str, nil)
-	}
-
-	// The network associated with the block must match the current active
-	// network, otherwise somebody probably put the block files for the
-	// wrong network in the directory.
-	serializedNet := byteOrder.Uint32(serializedData[:4])
-	if serializedNet != uint32(s.network) {
-		str := fmt.Sprintf("block data for block %s is for the "+
-			"wrong network - got %d, want %d", hash, serializedNet,
-			uint32(s.network))
-		return nil, makeDbErr(database.ErrDriverSpecific, str, nil)
-	}
-
-	// The raw block excludes the network, length of the block, and
-	// checksum.
-	return serializedData[8 : n-4], nil
-}
-
-// readBlockRegion reads the specified amount of data at the provided offset for
-// a given block location. The offset is relative to the start of the
-// serialized block (as opposed to the beginning of the block record). This
-// function automatically handles all file management such as opening and
-// closing files as necessary to stay within the maximum allowed open files
-// limit.
-//
-// Returns ErrDriverSpecific if the data fails to read for any reason.
-func (s *blockStore) readBlockRegion(loc blockLocation, offset, numBytes uint32) ([]byte, error) {
-	// Get the referenced block file handle opening the file as needed. The
-	// function also handles closing files as needed to avoid going over the
-	// max allowed open files.
-	blockFile, err := s.blockFile(loc.blockFileNum)
-	if err != nil {
-		return nil, err
-	}
-
-	// Regions are offsets into the actual block, however the serialized
-	// data for a block includes an initial 4 bytes for network + 4 bytes
-	// for block length. Thus, add 8 bytes to adjust.
-	readOffset := loc.fileOffset + 8 + offset
-	serializedData := make([]byte, numBytes)
-	_, err = blockFile.file.ReadAt(serializedData, int64(readOffset))
-	blockFile.RUnlock()
-	if err != nil {
-		str := fmt.Sprintf("failed to read region from block file %d, "+
-			"offset %d, len %d: %s", loc.blockFileNum, readOffset,
-			numBytes, err)
-		return nil, makeDbErr(database.ErrDriverSpecific, str, err)
-	}
-
-	return serializedData, nil
-}
-
-// syncBlocks performs a file system sync on the flat file associated with the
-// store's current write cursor. It is safe to call even when there is not a
-// current write file in which case it will have no effect.
-//
-// This is used when flushing cached metadata updates to disk to ensure all the
-// block data is fully written before updating the metadata. This ensures the
-// metadata and block data can be properly reconciled in failure scenarios.
-func (s *blockStore) syncBlocks() error {
-	wc := s.writeCursor
-	wc.RLock()
-	defer wc.RUnlock()
-
-	// Nothing to do if there is no current file associated with the write
-	// cursor.
-	wc.curFile.RLock()
-	defer wc.curFile.RUnlock()
-	if wc.curFile.file == nil {
-		return nil
-	}
-
-	// Sync the file to disk.
-	if err := wc.curFile.file.Sync(); err != nil {
-		str := fmt.Sprintf("failed to sync file %d: %s", wc.curFileNum,
-			err)
-		return makeDbErr(database.ErrDriverSpecific, str, err)
-	}
-
-	return nil
-}
-
-// handleRollback rolls the block files on disk back to the provided file number
-// and offset. This involves potentially deleting and truncating the files that
-// were partially written.
-//
-// There are effectively two scenarios to consider here:
-//   1) Transient write failures from which recovery is possible
-//   2) More permanent failures such as hard disk death and/or removal
-//
-// In either case, the write cursor will be repositioned to the old block file
-// offset regardless of any other errors that occur while attempting to undo
-// writes.
-//
-// For the first scenario, this will lead to any data which failed to be undone
-// being overwritten and thus behaves as desired as the system continues to run.
-//
-// For the second scenario, the metadata which stores the current write cursor
-// position within the block files will not have been updated yet and thus if
-// the system eventually recovers (perhaps the hard drive is reconnected), it
-// will also lead to any data which failed to be undone being overwritten and
-// thus behaves as desired.
-//
-// Therefore, any errors are simply logged at a warning level rather than being
-// returned since there is nothing more that could be done about it anyways.
-func (s *blockStore) handleRollback(oldBlockFileNum, oldBlockOffset uint32) {
-	// Grab the write cursor mutex since it is modified throughout this
-	// function.
-	wc := s.writeCursor
-	wc.Lock()
-	defer wc.Unlock()
-
-	// Nothing to do if the rollback point is the same as the current write
-	// cursor.
-	if wc.curFileNum == oldBlockFileNum && wc.curOffset == oldBlockOffset {
-		return
-	}
-
-	// Regardless of any failures that happen below, reposition the write
-	// cursor to the old block file and offset.
-	defer func() {
-		wc.curFileNum = oldBlockFileNum
-		wc.curOffset = oldBlockOffset
-	}()
-
-	log.Debugf("ROLLBACK: Rolling back to file %d, offset %d",
-		oldBlockFileNum, oldBlockOffset)
-
-	// Close the current write file if it needs to be deleted. Then delete
-	// all files that are newer than the provided rollback file while
-	// also moving the write cursor file backwards accordingly.
-	if wc.curFileNum > oldBlockFileNum {
-		wc.curFile.Lock()
-		if wc.curFile.file != nil {
-			_ = wc.curFile.file.Close()
-			wc.curFile.file = nil
-		}
-		wc.curFile.Unlock()
-	}
-	for ; wc.curFileNum > oldBlockFileNum; wc.curFileNum-- {
-		if err := s.deleteFileFunc(wc.curFileNum); err != nil {
-			log.Warnf("ROLLBACK: Failed to delete block file "+
-				"number %d: %s", wc.curFileNum, err)
-			return
-		}
-	}
-
-	// Open the file for the current write cursor if needed.
-	wc.curFile.Lock()
-	if wc.curFile.file == nil {
-		obf, err := s.openWriteFileFunc(wc.curFileNum)
-		if err != nil {
-			wc.curFile.Unlock()
-			log.Warnf("ROLLBACK: %s", err)
-			return
-		}
-		wc.curFile.file = obf
-	}
-
-	// Truncate the to the provided rollback offset.
-	if err := wc.curFile.file.Truncate(int64(oldBlockOffset)); err != nil {
-		wc.curFile.Unlock()
-		log.Warnf("ROLLBACK: Failed to truncate file %d: %s",
-			wc.curFileNum, err)
-		return
-	}
-
-	// Sync the file to disk.
-	err := wc.curFile.file.Sync()
-	wc.curFile.Unlock()
-	if err != nil {
-		log.Warnf("ROLLBACK: Failed to sync file %d: %s",
-			wc.curFileNum, err)
-		return
-	}
-}
-
-// scanBlockFiles searches the database directory for all flat block files to
-// find the end of the most recent file. This position is considered the
-// current write cursor which is also stored in the metadata. Thus, it is used
-// to detect unexpected shutdowns in the middle of writes so the block files
-// can be reconciled.
-func scanBlockFiles(dbPath string) (int, uint32) {
-	lastFile := -1
-	fileLen := uint32(0)
-	for i := 0; ; i++ {
-		filePath := blockFilePath(dbPath, uint32(i))
-		st, err := os.Stat(filePath)
-		if err != nil {
-			break
-		}
-		lastFile = i
-
-		fileLen = uint32(st.Size())
-	}
-
-	log.Tracef("Scan found latest block file #%d with length %d", lastFile,
-		fileLen)
-	return lastFile, fileLen
-}
-
-// newBlockStore returns a new block store with the current block file number
-// and offset set and all fields initialized.
-func newBlockStore(basePath string, network wire.KaspaNet) *blockStore {
-	// Look for the end of the latest block to file to determine what the
-	// write cursor position is from the viewpoing of the block files on
-	// disk.
-	fileNum, fileOff := scanBlockFiles(basePath)
-	if fileNum == -1 {
-		fileNum = 0
-		fileOff = 0
-	}
-
-	store := &blockStore{
-		network:          network,
-		basePath:         basePath,
-		maxBlockFileSize: maxBlockFileSize,
-		maxOpenFiles:     maxOpenFiles,
-		openBlockFiles:   make(map[uint32]*lockableFile),
-		openBlocksLRU:    list.New(),
-		fileNumToLRUElem: make(map[uint32]*list.Element),
-
-		writeCursor: &writeCursor{
-			curFile:    &lockableFile{},
-			curFileNum: uint32(fileNum),
-			curOffset:  fileOff,
-		},
-	}
-	store.openFileFunc = store.openFile
-	store.openWriteFileFunc = store.openWriteFile
-	store.deleteFileFunc = store.deleteFile
-	return store
-}

database/ffldb/blockio_test.go

@@ -1,108 +0,0 @@
-package ffldb
-
-import (
-	"os"
-	"testing"
-
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/util"
-	"github.com/kaspanet/kaspad/util/daghash"
-	"github.com/kaspanet/kaspad/wire"
-)
-
-func TestDeleteFile(t *testing.T) {
-	testBlock := util.NewBlock(wire.NewMsgBlock(
-		wire.NewBlockHeader(1, []*daghash.Hash{}, &daghash.Hash{}, &daghash.Hash{}, &daghash.Hash{}, 0, 0)))
-
-	tests := []struct {
-		fileNum     uint32
-		expectedErr bool
-	}{
-		{0, false},
-		{1, true},
-	}
-
-	for _, test := range tests {
-		func() {
-			pdb := newTestDb("TestDeleteFile", t)
-			defer func() {
-				if !pdb.closed {
-					pdb.Close()
-				}
-			}()
-
-			err := pdb.Update(func(dbTx database.Tx) error {
-				dbTx.StoreBlock(testBlock)
-				return nil
-			})
-			if err != nil {
-				t.Fatalf("TestDeleteFile: Error storing block: %s", err)
-			}
-
-			err = pdb.Close()
-			if err != nil {
-				t.Fatalf("TestDeleteFile: Error closing file before deletion: %s", err)
-			}
-
-			err = pdb.store.deleteFile(test.fileNum)
-			if (err != nil) != test.expectedErr {
-				t.Errorf("TestDeleteFile: %d: Expected error status: %t, but got: %t",
-					test.fileNum, test.expectedErr, (err != nil))
-			}
-			if err == nil {
-				filePath := blockFilePath(pdb.store.basePath, test.fileNum)
-				if _, err := os.Stat(filePath); !os.IsNotExist(err) {
-					t.Errorf("TestDeleteFile: %d: File %s still exists", test.fileNum, filePath)
-				}
-			}
-		}()
-	}
-}
-
-// TestHandleRollbackErrors tests all error-cases in *blockStore.handleRollback().
-// The non-error-cases are tested in the more general tests.
-// Since handleRollback just logs errors, this test simply causes all error-cases to be hit,
-// and makes sure no panic occurs, as well as ensures the writeCursor was updated correctly.
-func TestHandleRollbackErrors(t *testing.T) {
-	testBlock := util.NewBlock(wire.NewMsgBlock(
-		wire.NewBlockHeader(1, []*daghash.Hash{}, &daghash.Hash{}, &daghash.Hash{}, &daghash.Hash{}, 0, 0)))
-
-	testBlockSize := uint32(testBlock.MsgBlock().SerializeSize())
-	tests := []struct {
-		name    string
-		fileNum uint32
-		offset  uint32
-	}{
-		// offset should be size of block + 12 bytes for block network, size and checksum
-		{"Nothing to rollback", 1, testBlockSize + 12},
-	}
-
-	for _, test := range tests {
-		func() {
-			pdb := newTestDb("TestHandleRollbackErrors", t)
-			defer pdb.Close()
-
-			// Set maxBlockFileSize to testBlockSize so that writeCursor.curFileNum increments
-			pdb.store.maxBlockFileSize = testBlockSize
-
-			err := pdb.Update(func(dbTx database.Tx) error {
-				return dbTx.StoreBlock(testBlock)
-			})
-			if err != nil {
-				t.Fatalf("TestHandleRollbackErrors: %s: Error adding test block to database: %s", test.name, err)
-			}
-
-			pdb.store.handleRollback(test.fileNum, test.offset)
-
-			if pdb.store.writeCursor.curFileNum != test.fileNum {
-				t.Errorf("TestHandleRollbackErrors: %s: Expected fileNum: %d, but got: %d",
-					test.name, test.fileNum, pdb.store.writeCursor.curFileNum)
-			}
-
-			if pdb.store.writeCursor.curOffset != test.offset {
-				t.Errorf("TestHandleRollbackErrors: %s: offset fileNum: %d, but got: %d",
-					test.name, test.offset, pdb.store.writeCursor.curOffset)
-			}
-		}()
-	}
-}

database/ffldb/common_test.go

@@ -1,43 +0,0 @@
-package ffldb
-
-import (
-	"os"
-	"path"
-	"path/filepath"
-	"testing"
-
-	"github.com/kaspanet/kaspad/wire"
-	"github.com/syndtr/goleveldb/leveldb"
-	"github.com/syndtr/goleveldb/leveldb/filter"
-	"github.com/syndtr/goleveldb/leveldb/opt"
-)
-
-func newTestDb(testName string, t *testing.T) *db {
-	dbPath := path.Join(os.TempDir(), "db_test", testName)
-	err := os.RemoveAll(dbPath)
-	if err != nil && !os.IsNotExist(err) {
-		t.Fatalf("%s: Error deleting database folder before starting: %s", testName, err)
-	}
-
-	network := wire.Simnet
-
-	opts := opt.Options{
-		ErrorIfExist: true,
-		Strict:       opt.DefaultStrict,
-		Compression:  opt.NoCompression,
-		Filter:       filter.NewBloomFilter(10),
-	}
-	metadataDbPath := filepath.Join(dbPath, metadataDbName)
-	ldb, err := leveldb.OpenFile(metadataDbPath, &opts)
-	if err != nil {
-		t.Errorf("%s: Error opening metadataDbPath: %s", testName, err)
-	}
-	err = initDB(ldb)
-	if err != nil {
-		t.Errorf("%s: Error initializing metadata Db: %s", testName, err)
-	}
-
-	store := newBlockStore(dbPath, network)
-	cache := newDbCache(ldb, store, defaultCacheSize, defaultFlushSecs)
-	return &db{store: store, cache: cache}
-}

database/ffldb/db_test.go

@@ -1,658 +0,0 @@
-package ffldb
-
-import (
-	"bytes"
-	"testing"
-
-	"github.com/pkg/errors"
-
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/util"
-	"github.com/kaspanet/kaspad/util/daghash"
-	"github.com/kaspanet/kaspad/wire"
-)
-
-// TestCursorDeleteErrors tests all error-cases in *cursor.Delete().
-// The non-error-cases are tested in the more general tests.
-func TestCursorDeleteErrors(t *testing.T) {
-	pdb := newTestDb("TestCursorDeleteErrors", t)
-
-	nestedBucket := []byte("nestedBucket")
-	key := []byte("key")
-	value := []byte("value")
-
-	err := pdb.Update(func(dbTx database.Tx) error {
-		metadata := dbTx.Metadata()
-		_, err := metadata.CreateBucket(nestedBucket)
-		if err != nil {
-			return err
-		}
-		metadata.Put(key, value)
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestCursorDeleteErrors: Error setting up test-database: %s", err)
-	}
-
-	// Check for error when attempted to delete a bucket
-	err = pdb.Update(func(dbTx database.Tx) error {
-		cursor := dbTx.Metadata().Cursor()
-		found := false
-		for ok := cursor.First(); ok; ok = cursor.Next() {
-			if bytes.Equal(cursor.Key(), nestedBucket) {
-				found = true
-				break
-			}
-		}
-		if !found {
-			t.Errorf("TestCursorDeleteErrors: Key '%s' not found", string(nestedBucket))
-		}
-
-		err := cursor.Delete()
-		if !database.IsErrorCode(err, database.ErrIncompatibleValue) {
-			t.Errorf("TestCursorDeleteErrors: Expected error of type ErrIncompatibleValue, "+
-				"when deleting bucket, but got %v", err)
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestCursorDeleteErrors: Unexpected error from pdb.Update "+
-			"when attempting to delete bucket: %s", err)
-	}
-
-	// Check for error when transaction is not writable
-	err = pdb.View(func(dbTx database.Tx) error {
-		cursor := dbTx.Metadata().Cursor()
-		if !cursor.First() {
-			t.Fatal("TestCursorDeleteErrors: Nothing in cursor when testing for delete in " +
-				"non-writable transaction")
-		}
-
-		err := cursor.Delete()
-		if !database.IsErrorCode(err, database.ErrTxNotWritable) {
-			t.Errorf("TestCursorDeleteErrors: Expected error of type ErrTxNotWritable "+
-				"when calling .Delete() on non-writable transaction, but got '%v' instead", err)
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestCursorDeleteErrors: Unexpected error from pdb.Update "+
-			"when attempting to delete on non-writable transaction: %s", err)
-	}
-
-	// Check for error when cursor was exhausted
-	err = pdb.Update(func(dbTx database.Tx) error {
-		cursor := dbTx.Metadata().Cursor()
-		for ok := cursor.First(); ok; ok = cursor.Next() {
-		}
-
-		err := cursor.Delete()
-		if !database.IsErrorCode(err, database.ErrIncompatibleValue) {
-			t.Errorf("TestCursorDeleteErrors: Expected error of type ErrIncompatibleValue "+
-				"when calling .Delete() on exhausted cursor, but got '%v' instead", err)
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestCursorDeleteErrors: Unexpected error from pdb.Update "+
-			"when attempting to delete on exhausted cursor: %s", err)
-	}
-
-	// Check for error when transaction is closed
-	tx, err := pdb.Begin(true)
-	if err != nil {
-		t.Fatalf("TestCursorDeleteErrors: Error in pdb.Begin(): %s", err)
-	}
-	cursor := tx.Metadata().Cursor()
-	err = tx.Commit()
-	if err != nil {
-		t.Fatalf("TestCursorDeleteErrors: Error in tx.Commit(): %s", err)
-	}
-
-	err = cursor.Delete()
-	if !database.IsErrorCode(err, database.ErrTxClosed) {
-		t.Errorf("TestCursorDeleteErrors: Expected error of type ErrTxClosed "+
-			"when calling .Delete() on with closed transaction, but got '%s' instead", err)
-	}
-}
-
-func TestSkipPendingUpdates(t *testing.T) {
-	pdb := newTestDb("TestSkipPendingUpdates", t)
-	defer pdb.Close()
-
-	value := []byte("value")
-	// Add numbered prefixes to keys so that they are in expected order, and before any other keys
-	firstKey := []byte("1 - first")
-	toDeleteKey := []byte("2 - toDelete")
-	toUpdateKey := []byte("3 - toUpdate")
-	secondKey := []byte("4 - second")
-
-	// create initial metadata for test
-	err := pdb.Update(func(dbTx database.Tx) error {
-		metadata := dbTx.Metadata()
-		if err := metadata.Put(firstKey, value); err != nil {
-			return err
-		}
-		if err := metadata.Put(toDeleteKey, value); err != nil {
-			return err
-		}
-		if err := metadata.Put(toUpdateKey, value); err != nil {
-			return err
-		}
-		if err := metadata.Put(secondKey, value); err != nil {
-			return err
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestSkipPendingUpdates: Error adding to metadata: %s", err)
-	}
-
-	// test skips
-	err = pdb.Update(func(dbTx database.Tx) error {
-		metadata := dbTx.Metadata()
-		if err := metadata.Delete(toDeleteKey); err != nil {
-			return err
-		}
-		if err := metadata.Put(toUpdateKey, value); err != nil {
-			return err
-		}
-		cursor := metadata.Cursor().(*cursor)
-		dbIter := cursor.dbIter
-
-		// Check that first is ok
-		dbIter.First()
-		expectedKey := bucketizedKey(metadataBucketID, firstKey)
-		if !bytes.Equal(dbIter.Key(), expectedKey) {
-			t.Errorf("TestSkipPendingUpdates: 1: key expected to be %v but is %v", expectedKey, dbIter.Key())
-		}
-
-		// Go to the next key, which is toDelete
-		dbIter.Next()
-		expectedKey = bucketizedKey(metadataBucketID, toDeleteKey)
-		if !bytes.Equal(dbIter.Key(), expectedKey) {
-			t.Errorf("TestSkipPendingUpdates: 2: key expected to be %s but is %s", expectedKey, dbIter.Key())
-		}
-
-		// at this point toDeleteKey and toUpdateKey should be skipped
-		cursor.skipPendingUpdates(true)
-		expectedKey = bucketizedKey(metadataBucketID, secondKey)
-		if !bytes.Equal(dbIter.Key(), expectedKey) {
-			t.Errorf("TestSkipPendingUpdates: 3: key expected to be %s but is %s", expectedKey, dbIter.Key())
-		}
-
-		// now traverse backwards - should get toUpdate
-		dbIter.Prev()
-		expectedKey = bucketizedKey(metadataBucketID, toUpdateKey)
-		if !bytes.Equal(dbIter.Key(), expectedKey) {
-			t.Errorf("TestSkipPendingUpdates: 4: key expected to be %s but is %s", expectedKey, dbIter.Key())
-		}
-
-		// at this point toUpdateKey and toDeleteKey should be skipped
-		cursor.skipPendingUpdates(false)
-		expectedKey = bucketizedKey(metadataBucketID, firstKey)
-		if !bytes.Equal(dbIter.Key(), expectedKey) {
-			t.Errorf("TestSkipPendingUpdates: 5: key expected to be %s but is %s", expectedKey, dbIter.Key())
-		}
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestSkipPendingUpdates: Error running main part of test: %s", err)
-	}
-}
-
-// TestCursor tests various edge-cases in cursor that were not hit by the more general tests
-func TestCursor(t *testing.T) {
-	pdb := newTestDb("TestCursor", t)
-	defer pdb.Close()
-
-	value := []byte("value")
-	// Add numbered prefixes to keys so that they are in expected order, and before any other keys
-	firstKey := []byte("1 - first")
-	toDeleteKey := []byte("2 - toDelete")
-	toUpdateKey := []byte("3 - toUpdate")
-	secondKey := []byte("4 - second")
-
-	// create initial metadata for test
-	err := pdb.Update(func(dbTx database.Tx) error {
-		metadata := dbTx.Metadata()
-		if err := metadata.Put(firstKey, value); err != nil {
-			return err
-		}
-		if err := metadata.Put(toDeleteKey, value); err != nil {
-			return err
-		}
-		if err := metadata.Put(toUpdateKey, value); err != nil {
-			return err
-		}
-		if err := metadata.Put(secondKey, value); err != nil {
-			return err
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("Error adding to metadata: %s", err)
-	}
-
-	// run the actual tests
-	err = pdb.Update(func(dbTx database.Tx) error {
-		metadata := dbTx.Metadata()
-		if err := metadata.Delete(toDeleteKey); err != nil {
-			return err
-		}
-		if err := metadata.Put(toUpdateKey, value); err != nil {
-			return err
-		}
-		cursor := metadata.Cursor().(*cursor)
-
-		// Check prev when currentIter == nil
-		if ok := cursor.Prev(); ok {
-			t.Error("1: .Prev() should have returned false, but have returned true")
-		}
-		// Same thing for .Next()
-		for ok := cursor.First(); ok; ok = cursor.Next() {
-		}
-		if ok := cursor.Next(); ok {
-			t.Error("2: .Next() should have returned false, but have returned true")
-		}
-
-		// Check that Key(), rawKey(), Value(), and rawValue() all return nil when currentIter == nil
-		if key := cursor.Key(); key != nil {
-			t.Errorf("3: .Key() should have returned nil, but have returned '%s' instead", key)
-		}
-		if key := cursor.rawKey(); key != nil {
-			t.Errorf("4: .rawKey() should have returned nil, but have returned '%s' instead", key)
-		}
-		if value := cursor.Value(); value != nil {
-			t.Errorf("5: .Value() should have returned nil, but have returned '%s' instead", value)
-		}
-		if value := cursor.rawValue(); value != nil {
-			t.Errorf("6: .rawValue() should have returned nil, but have returned '%s' instead", value)
-		}
-
-		// Check rawValue in normal operation
-		cursor.First()
-		if rawValue := cursor.rawValue(); !bytes.Equal(rawValue, value) {
-			t.Errorf("7: rawValue should have returned '%s' but have returned '%s' instead", value, rawValue)
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("Error running the actual tests: %s", err)
-	}
-}
-
-// TestCreateBucketErrors tests all error-cases in *bucket.CreateBucket().
-// The non-error-cases are tested in the more general tests.
-func TestCreateBucketErrors(t *testing.T) {
-	testKey := []byte("key")
-
-	tests := []struct {
-		name        string
-		key         []byte
-		isWritable  bool
-		isClosed    bool
-		expectedErr database.ErrorCode
-	}{
-		{"empty key", []byte{}, true, false, database.ErrBucketNameRequired},
-		{"transaction is closed", testKey, true, true, database.ErrTxClosed},
-		{"transaction is not writable", testKey, false, false, database.ErrTxNotWritable},
-		{"key already exists", blockIdxBucketName, true, false, database.ErrBucketExists},
-	}
-
-	for _, test := range tests {
-		func() {
-			pdb := newTestDb("TestCreateBucketErrors", t)
-			defer pdb.Close()
-
-			tx, err := pdb.Begin(test.isWritable)
-			defer tx.Commit()
-			if err != nil {
-				t.Fatalf("TestCreateBucketErrors: %s: error from pdb.Begin: %s", test.name, err)
-			}
-			if test.isClosed {
-				err = tx.Commit()
-				if err != nil {
-					t.Fatalf("TestCreateBucketErrors: %s: error from tx.Commit: %s", test.name, err)
-				}
-			}
-
-			metadata := tx.Metadata()
-
-			_, err = metadata.CreateBucket(test.key)
-
-			if !database.IsErrorCode(err, test.expectedErr) {
-				t.Errorf("TestCreateBucketErrors: %s: Expected error of type %d "+
-					"but got '%v'", test.name, test.expectedErr, err)
-			}
-
-		}()
-	}
-}
-
-// TestPutErrors tests all error-cases in *bucket.Put().
-// The non-error-cases are tested in the more general tests.
-func TestPutErrors(t *testing.T) {
-	testKey := []byte("key")
-	testValue := []byte("value")
-
-	tests := []struct {
-		name        string
-		key         []byte
-		isWritable  bool
-		isClosed    bool
-		expectedErr database.ErrorCode
-	}{
-		{"empty key", []byte{}, true, false, database.ErrKeyRequired},
-		{"transaction is closed", testKey, true, true, database.ErrTxClosed},
-		{"transaction is not writable", testKey, false, false, database.ErrTxNotWritable},
-	}
-
-	for _, test := range tests {
-		func() {
-			pdb := newTestDb("TestPutErrors", t)
-			defer pdb.Close()
-
-			tx, err := pdb.Begin(test.isWritable)
-			defer tx.Commit()
-			if err != nil {
-				t.Fatalf("TestPutErrors: %s: error from pdb.Begin: %s", test.name, err)
-			}
-			if test.isClosed {
-				err = tx.Commit()
-				if err != nil {
-					t.Fatalf("TestPutErrors: %s: error from tx.Commit: %s", test.name, err)
-				}
-			}
-
-			metadata := tx.Metadata()
-
-			err = metadata.Put(test.key, testValue)
-
-			if !database.IsErrorCode(err, test.expectedErr) {
-				t.Errorf("TestPutErrors: %s: Expected error of type %d "+
-					"but got '%v'", test.name, test.expectedErr, err)
-			}
-
-		}()
-	}
-}
-
-// TestGetErrors tests all error-cases in *bucket.Get().
-// The non-error-cases are tested in the more general tests.
-func TestGetErrors(t *testing.T) {
-	testKey := []byte("key")
-
-	tests := []struct {
-		name     string
-		key      []byte
-		isClosed bool
-	}{
-		{"empty key", []byte{}, false},
-		{"transaction is closed", testKey, true},
-	}
-
-	for _, test := range tests {
-		func() {
-			pdb := newTestDb("TestGetErrors", t)
-			defer pdb.Close()
-
-			tx, err := pdb.Begin(false)
-			defer tx.Rollback()
-			if err != nil {
-				t.Fatalf("TestGetErrors: %s: error from pdb.Begin: %s", test.name, err)
-			}
-			if test.isClosed {
-				err = tx.Rollback()
-				if err != nil {
-					t.Fatalf("TestGetErrors: %s: error from tx.Commit: %s", test.name, err)
-				}
-			}
-
-			metadata := tx.Metadata()
-
-			if result := metadata.Get(test.key); result != nil {
-				t.Errorf("TestGetErrors: %s: Expected to return nil, but got %v", test.name, result)
-			}
-		}()
-	}
-}
-
-// TestDeleteErrors tests all error-cases in *bucket.Delete().
-// The non-error-cases are tested in the more general tests.
-func TestDeleteErrors(t *testing.T) {
-	testKey := []byte("key")
-
-	tests := []struct {
-		name        string
-		key         []byte
-		isWritable  bool
-		isClosed    bool
-		expectedErr database.ErrorCode
-	}{
-		{"empty key", []byte{}, true, false, database.ErrKeyRequired},
-		{"transaction is closed", testKey, true, true, database.ErrTxClosed},
-		{"transaction is not writable", testKey, false, false, database.ErrTxNotWritable},
-	}
-
-	for _, test := range tests {
-		func() {
-			pdb := newTestDb("TestDeleteErrors", t)
-			defer pdb.Close()
-
-			tx, err := pdb.Begin(test.isWritable)
-			defer tx.Commit()
-			if err != nil {
-				t.Fatalf("TestDeleteErrors: %s: error from pdb.Begin: %s", test.name, err)
-			}
-			if test.isClosed {
-				err = tx.Commit()
-				if err != nil {
-					t.Fatalf("TestDeleteErrors: %s: error from tx.Commit: %s", test.name, err)
-				}
-			}
-
-			metadata := tx.Metadata()
-
-			err = metadata.Delete(test.key)
-
-			if !database.IsErrorCode(err, test.expectedErr) {
-				t.Errorf("TestDeleteErrors: %s: Expected error of type %d "+
-					"but got '%v'", test.name, test.expectedErr, err)
-			}
-		}()
-	}
-}
-
-func TestForEachBucket(t *testing.T) {
-	pdb := newTestDb("TestForEachBucket", t)
-
-	// set-up test
-	testKey := []byte("key")
-	testValue := []byte("value")
-	bucketKeys := [][]byte{{1}, {2}, {3}}
-
-	err := pdb.Update(func(dbTx database.Tx) error {
-		metadata := dbTx.Metadata()
-		for _, bucketKey := range bucketKeys {
-			bucket, err := metadata.CreateBucket(bucketKey)
-			if err != nil {
-				return err
-			}
-
-			err = bucket.Put(testKey, testValue)
-			if err != nil {
-				return err
-			}
-		}
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestForEachBucket: Error setting up test-database: %s", err)
-	}
-
-	// actual test
-	err = pdb.View(func(dbTx database.Tx) error {
-		i := 0
-		metadata := dbTx.Metadata()
-
-		err := metadata.ForEachBucket(func(bucketKey []byte) error {
-			if i >= len(bucketKeys) { // in case there are any other buckets in metadata
-				return nil
-			}
-
-			expectedBucketKey := bucketKeys[i]
-			if !bytes.Equal(expectedBucketKey, bucketKey) {
-				t.Errorf("TestForEachBucket: %d: Expected bucket key: %v, but got: %v",
-					i, expectedBucketKey, bucketKey)
-				return nil
-			}
-			bucket := metadata.Bucket(bucketKey)
-			if bucket == nil {
-				t.Errorf("TestForEachBucket: %d: Bucket is nil", i)
-				return nil
-			}
-
-			value := bucket.Get(testKey)
-			if !bytes.Equal(testValue, value) {
-				t.Errorf("TestForEachBucket: %d: Expected value: %s, but got: %s",
-					i, testValue, value)
-				return nil
-			}
-
-			i++
-			return nil
-		})
-
-		return err
-	})
-	if err != nil {
-		t.Fatalf("TestForEachBucket: Error running actual tests: %s", err)
-	}
-}
-
-// TestStoreBlockErrors tests all error-cases in *tx.StoreBlock().
-// The non-error-cases are tested in the more general tests.
-func TestStoreBlockErrors(t *testing.T) {
-	testBlock := util.NewBlock(wire.NewMsgBlock(wire.NewBlockHeader(1, []*daghash.Hash{}, &daghash.Hash{}, &daghash.Hash{}, &daghash.Hash{}, 0, 0)))
-
-	tests := []struct {
-		name        string
-		isWritable  bool
-		isClosed    bool
-		expectedErr database.ErrorCode
-	}{
-		{"transaction is closed", true, true, database.ErrTxClosed},
-		{"transaction is not writable", false, false, database.ErrTxNotWritable},
-	}
-
-	for _, test := range tests {
-		func() {
-			pdb := newTestDb("TestStoreBlockErrors", t)
-			defer pdb.Close()
-
-			tx, err := pdb.Begin(test.isWritable)
-			defer tx.Commit()
-			if err != nil {
-				t.Fatalf("TestStoreBlockErrors: %s: error from pdb.Begin: %s", test.name, err)
-			}
-			if test.isClosed {
-				err = tx.Commit()
-				if err != nil {
-					t.Fatalf("TestStoreBlockErrors: %s: error from tx.Commit: %s", test.name, err)
-				}
-			}
-
-			err = tx.StoreBlock(testBlock)
-			if !database.IsErrorCode(err, test.expectedErr) {
-				t.Errorf("TestStoreBlockErrors: %s: Expected error of type %d "+
-					"but got '%v'", test.name, test.expectedErr, err)
-			}
-
-		}()
-	}
-}
-
-// TestDeleteDoubleNestedBucket tests what happens when bucket.DeleteBucket()
-// is invoked on a bucket that contains a nested bucket.
-func TestDeleteDoubleNestedBucket(t *testing.T) {
-	pdb := newTestDb("TestDeleteDoubleNestedBucket", t)
-	defer pdb.Close()
-
-	firstKey := []byte("first")
-	secondKey := []byte("second")
-	key := []byte("key")
-	value := []byte("value")
-	var rawKey, rawSecondKey []byte
-
-	// Test setup
-	err := pdb.Update(func(dbTx database.Tx) error {
-		metadata := dbTx.Metadata()
-		firstBucket, err := metadata.CreateBucket(firstKey)
-		if err != nil {
-			return errors.Errorf("Error creating first bucket: %s", err)
-		}
-		secondBucket, err := firstBucket.CreateBucket(secondKey)
-		if err != nil {
-			return errors.Errorf("Error creating second bucket: %s", err)
-		}
-		secondBucket.Put(key, value)
-
-		// extract rawKey from cursor and make sure it's in raw database
-		c := secondBucket.Cursor()
-		for ok := c.First(); ok && !bytes.Equal(c.Key(), key); ok = c.Next() {
-		}
-		if !bytes.Equal(c.Key(), key) {
-			return errors.Errorf("Couldn't find key to extract rawKey")
-		}
-		rawKey = c.(*cursor).rawKey()
-		if dbTx.(*transaction).fetchKey(rawKey) == nil {
-			return errors.Errorf("rawKey not found")
-		}
-
-		// extract rawSecondKey from cursor and make sure it's in raw database
-		c = firstBucket.Cursor()
-		for ok := c.First(); ok && !bytes.Equal(c.Key(), secondKey); ok = c.Next() {
-		}
-		if !bytes.Equal(c.Key(), secondKey) {
-			return errors.Errorf("Couldn't find secondKey to extract rawSecondKey")
-		}
-		rawSecondKey = c.(*cursor).rawKey()
-		if dbTx.(*transaction).fetchKey(rawSecondKey) == nil {
-			return errors.Errorf("rawSecondKey not found for some reason")
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestDeleteDoubleNestedBucket: Error in test setup pdb.Update: %s", err)
-	}
-
-	// Actual test
-	err = pdb.Update(func(dbTx database.Tx) error {
-		metadata := dbTx.Metadata()
-		err := metadata.DeleteBucket(firstKey)
-		if err != nil {
-			return err
-		}
-
-		if dbTx.(*transaction).fetchKey(rawSecondKey) != nil {
-			t.Error("TestDeleteDoubleNestedBucket: secondBucket was not deleted")
-		}
-
-		if dbTx.(*transaction).fetchKey(rawKey) != nil {
-			t.Error("TestDeleteDoubleNestedBucket: value inside secondBucket was not deleted")
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestDeleteDoubleNestedBucket: Error in actual test pdb.Update: %s", err)
-	}
-}

database/ffldb/dbcache.go

@@ -1,647 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package ffldb
-
-import (
-	"bytes"
-	"fmt"
-	"sync"
-	"time"
-
-	"github.com/kaspanet/kaspad/database/internal/treap"
-	"github.com/syndtr/goleveldb/leveldb"
-	"github.com/syndtr/goleveldb/leveldb/iterator"
-	"github.com/syndtr/goleveldb/leveldb/util"
-)
-
-const (
-	// defaultCacheSize is the default size for the database cache.
-	defaultCacheSize = 100 * 1024 * 1024 // 100 MB
-
-	// defaultFlushSecs is the default number of seconds to use as a
-	// threshold in between database cache flushes when the cache size has
-	// not been exceeded.
-	defaultFlushSecs = 300 // 5 minutes
-)
-
-// ldbCacheIter wraps a treap iterator to provide the additional functionality
-// needed to satisfy the leveldb iterator.Iterator interface.
-type ldbCacheIter struct {
-	*treap.Iterator
-}
-
-// Enforce ldbCacheIterator implements the leveldb iterator.Iterator interface.
-var _ iterator.Iterator = (*ldbCacheIter)(nil)
-
-// Error is only provided to satisfy the iterator interface as there are no
-// errors for this memory-only structure.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *ldbCacheIter) Error() error {
-	return nil
-}
-
-// SetReleaser is only provided to satisfy the iterator interface as there is no
-// need to override it.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *ldbCacheIter) SetReleaser(releaser util.Releaser) {
-}
-
-// Release is only provided to satisfy the iterator interface.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *ldbCacheIter) Release() {
-}
-
-// newLdbCacheIter creates a new treap iterator for the given slice against the
-// pending keys for the passed cache snapshot and returns it wrapped in an
-// ldbCacheIter so it can be used as a leveldb iterator.
-func newLdbCacheIter(snap *dbCacheSnapshot, slice *util.Range) *ldbCacheIter {
-	iter := snap.pendingKeys.Iterator(slice.Start, slice.Limit)
-	return &ldbCacheIter{Iterator: iter}
-}
-
-// dbCacheIterator defines an iterator over the key/value pairs in the database
-// cache and underlying database.
-type dbCacheIterator struct {
-	cacheSnapshot *dbCacheSnapshot
-	dbIter        iterator.Iterator
-	cacheIter     iterator.Iterator
-	currentIter   iterator.Iterator
-	released      bool
-}
-
-// Enforce dbCacheIterator implements the leveldb iterator.Iterator interface.
-var _ iterator.Iterator = (*dbCacheIterator)(nil)
-
-// skipPendingUpdates skips any keys at the current database iterator position
-// that are being updated by the cache. The forwards flag indicates the
-// direction the iterator is moving.
-func (iter *dbCacheIterator) skipPendingUpdates(forwards bool) {
-	for iter.dbIter.Valid() {
-		var skip bool
-		key := iter.dbIter.Key()
-		if iter.cacheSnapshot.pendingRemove.Has(key) {
-			skip = true
-		} else if iter.cacheSnapshot.pendingKeys.Has(key) {
-			skip = true
-		}
-		if !skip {
-			break
-		}
-
-		if forwards {
-			iter.dbIter.Next()
-		} else {
-			iter.dbIter.Prev()
-		}
-	}
-}
-
-// chooseIterator first skips any entries in the database iterator that are
-// being updated by the cache and sets the current iterator to the appropriate
-// iterator depending on their validity and the order they compare in while taking
-// into account the direction flag. When the iterator is being moved forwards
-// and both iterators are valid, the iterator with the smaller key is chosen and
-// vice versa when the iterator is being moved backwards.
-func (iter *dbCacheIterator) chooseIterator(forwards bool) bool {
-	// Skip any keys at the current database iterator position that are
-	// being updated by the cache.
-	iter.skipPendingUpdates(forwards)
-
-	// When both iterators are exhausted, the iterator is exhausted too.
-	if !iter.dbIter.Valid() && !iter.cacheIter.Valid() {
-		iter.currentIter = nil
-		return false
-	}
-
-	// Choose the database iterator when the cache iterator is exhausted.
-	if !iter.cacheIter.Valid() {
-		iter.currentIter = iter.dbIter
-		return true
-	}
-
-	// Choose the cache iterator when the database iterator is exhausted.
-	if !iter.dbIter.Valid() {
-		iter.currentIter = iter.cacheIter
-		return true
-	}
-
-	// Both iterators are valid, so choose the iterator with either the
-	// smaller or larger key depending on the forwards flag.
-	compare := bytes.Compare(iter.dbIter.Key(), iter.cacheIter.Key())
-	if (forwards && compare > 0) || (!forwards && compare < 0) {
-		iter.currentIter = iter.cacheIter
-	} else {
-		iter.currentIter = iter.dbIter
-	}
-	return true
-}
-
-// First positions the iterator at the first key/value pair and returns whether
-// or not the pair exists.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) First() bool {
-	// Seek to the first key in both the database and cache iterators and
-	// choose the iterator that is both valid and has the smaller key.
-	iter.dbIter.First()
-	iter.cacheIter.First()
-	return iter.chooseIterator(true)
-}
-
-// Last positions the iterator at the last key/value pair and returns whether or
-// not the pair exists.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) Last() bool {
-	// Seek to the last key in both the database and cache iterators and
-	// choose the iterator that is both valid and has the larger key.
-	iter.dbIter.Last()
-	iter.cacheIter.Last()
-	return iter.chooseIterator(false)
-}
-
-// Next moves the iterator one key/value pair forward and returns whether or not
-// the pair exists.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) Next() bool {
-	// Nothing to return if cursor is exhausted.
-	if iter.currentIter == nil {
-		return false
-	}
-
-	// Move the current iterator to the next entry and choose the iterator
-	// that is both valid and has the smaller key.
-	iter.currentIter.Next()
-	return iter.chooseIterator(true)
-}
-
-// Prev moves the iterator one key/value pair backward and returns whether or
-// not the pair exists.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) Prev() bool {
-	// Nothing to return if cursor is exhausted.
-	if iter.currentIter == nil {
-		return false
-	}
-
-	// Move the current iterator to the previous entry and choose the
-	// iterator that is both valid and has the larger key.
-	iter.currentIter.Prev()
-	return iter.chooseIterator(false)
-}
-
-// Seek positions the iterator at the first key/value pair that is greater than
-// or equal to the passed seek key. Returns false if no suitable key was found.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) Seek(key []byte) bool {
-	// Seek to the provided key in both the database and cache iterators
-	// then choose the iterator that is both valid and has the larger key.
-	iter.dbIter.Seek(key)
-	iter.cacheIter.Seek(key)
-	return iter.chooseIterator(true)
-}
-
-// Valid indicates whether the iterator is positioned at a valid key/value pair.
-// It will be considered invalid when the iterator is newly created or exhausted.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) Valid() bool {
-	return iter.currentIter != nil
-}
-
-// Key returns the current key the iterator is pointing to.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) Key() []byte {
-	// Nothing to return if iterator is exhausted.
-	if iter.currentIter == nil {
-		return nil
-	}
-
-	return iter.currentIter.Key()
-}
-
-// Value returns the current value the iterator is pointing to.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) Value() []byte {
-	// Nothing to return if iterator is exhausted.
-	if iter.currentIter == nil {
-		return nil
-	}
-
-	return iter.currentIter.Value()
-}
-
-// SetReleaser is only provided to satisfy the iterator interface as there is no
-// need to override it.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) SetReleaser(releaser util.Releaser) {
-}
-
-// Release releases the iterator by removing the underlying treap iterator from
-// the list of active iterators against the pending keys treap.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) Release() {
-	if !iter.released {
-		iter.dbIter.Release()
-		iter.cacheIter.Release()
-		iter.currentIter = nil
-		iter.released = true
-	}
-}
-
-// Error is only provided to satisfy the iterator interface as there are no
-// errors for this memory-only structure.
-//
-// This is part of the leveldb iterator.Iterator interface implementation.
-func (iter *dbCacheIterator) Error() error {
-	return nil
-}
-
-// dbCacheSnapshot defines a snapshot of the database cache and underlying
-// database at a particular point in time.
-type dbCacheSnapshot struct {
-	dbSnapshot    *leveldb.Snapshot
-	pendingKeys   *treap.Immutable
-	pendingRemove *treap.Immutable
-}
-
-// Has returns whether or not the passed key exists.
-func (snap *dbCacheSnapshot) Has(key []byte) bool {
-	// Check the cached entries first.
-	if snap.pendingRemove.Has(key) {
-		return false
-	}
-	if snap.pendingKeys.Has(key) {
-		return true
-	}
-
-	// Consult the database.
-	hasKey, _ := snap.dbSnapshot.Has(key, nil)
-	return hasKey
-}
-
-// Get returns the value for the passed key. The function will return nil when
-// the key does not exist.
-func (snap *dbCacheSnapshot) Get(key []byte) []byte {
-	// Check the cached entries first.
-	if snap.pendingRemove.Has(key) {
-		return nil
-	}
-	if value := snap.pendingKeys.Get(key); value != nil {
-		return value
-	}
-
-	// Consult the database.
-	value, err := snap.dbSnapshot.Get(key, nil)
-	if err != nil {
-		return nil
-	}
-	return value
-}
-
-// Release releases the snapshot.
-func (snap *dbCacheSnapshot) Release() {
-	snap.dbSnapshot.Release()
-	snap.pendingKeys = nil
-	snap.pendingRemove = nil
-}
-
-// NewIterator returns a new iterator for the snapshot. The newly returned
-// iterator is not pointing to a valid item until a call to one of the methods
-// to position it is made.
-//
-// The slice parameter allows the iterator to be limited to a range of keys.
-// The start key is inclusive and the limit key is exclusive. Either or both
-// can be nil if the functionality is not desired.
-func (snap *dbCacheSnapshot) NewIterator(slice *util.Range) *dbCacheIterator {
-	return &dbCacheIterator{
-		dbIter:        snap.dbSnapshot.NewIterator(slice, nil),
-		cacheIter:     newLdbCacheIter(snap, slice),
-		cacheSnapshot: snap,
-	}
-}
-
-// dbCache provides a database cache layer backed by an underlying database. It
-// allows a maximum cache size and flush interval to be specified such that the
-// cache is flushed to the database when the cache size exceeds the maximum
-// configured value or it has been longer than the configured interval since the
-// last flush. This effectively provides transaction batching so that callers
-// can commit transactions at will without incurring large performance hits due
-// to frequent disk syncs.
-type dbCache struct {
-	// ldb is the underlying leveldb DB for metadata.
-	ldb *leveldb.DB
-
-	// store is used to sync blocks to flat files.
-	store *blockStore
-
-	// The following fields are related to flushing the cache to persistent
-	// storage. Note that all flushing is performed in an opportunistic
-	// fashion. This means that it is only flushed during a transaction or
-	// when the database cache is closed.
-	//
-	// maxSize is the maximum size threshold the cache can grow to before
-	// it is flushed.
-	//
-	// flushInterval is the threshold interval of time that is allowed to
-	// pass before the cache is flushed.
-	//
-	// lastFlush is the time the cache was last flushed. It is used in
-	// conjunction with the current time and the flush interval.
-	//
-	// NOTE: These flush related fields are protected by the database write
-	// lock.
-	maxSize       uint64
-	flushInterval time.Duration
-	lastFlush     time.Time
-
-	// The following fields hold the keys that need to be stored or deleted
-	// from the underlying database once the cache is full, enough time has
-	// passed, or when the database is shutting down. Note that these are
-	// stored using immutable treaps to support O(1) MVCC snapshots against
-	// the cached data. The cacheLock is used to protect concurrent access
-	// for cache updates and snapshots.
-	cacheLock    sync.RWMutex
-	cachedKeys   *treap.Immutable
-	cachedRemove *treap.Immutable
-}
-
-// Snapshot returns a snapshot of the database cache and underlying database at
-// a particular point in time.
-//
-// The snapshot must be released after use by calling Release.
-func (c *dbCache) Snapshot() (*dbCacheSnapshot, error) {
-	dbSnapshot, err := c.ldb.GetSnapshot()
-	if err != nil {
-		str := "failed to open transaction"
-		return nil, convertErr(str, err)
-	}
-
-	// Since the cached keys to be added and removed use an immutable treap,
-	// a snapshot is simply obtaining the root of the tree under the lock
-	// which is used to atomically swap the root.
-	c.cacheLock.RLock()
-	cacheSnapshot := &dbCacheSnapshot{
-		dbSnapshot:    dbSnapshot,
-		pendingKeys:   c.cachedKeys,
-		pendingRemove: c.cachedRemove,
-	}
-	c.cacheLock.RUnlock()
-	return cacheSnapshot, nil
-}
-
-// updateDB invokes the passed function in the context of a managed leveldb
-// transaction. Any errors returned from the user-supplied function will cause
-// the transaction to be rolled back and are returned from this function.
-// Otherwise, the transaction is committed when the user-supplied function
-// returns a nil error.
-func (c *dbCache) updateDB(fn func(ldbTx *leveldb.Transaction) error) error {
-	// Start a leveldb transaction.
-	ldbTx, err := c.ldb.OpenTransaction()
-	if err != nil {
-		return convertErr("failed to open ldb transaction", err)
-	}
-
-	if err := fn(ldbTx); err != nil {
-		ldbTx.Discard()
-		return err
-	}
-
-	// Commit the leveldb transaction and convert any errors as needed.
-	if err := ldbTx.Commit(); err != nil {
-		return convertErr("failed to commit leveldb transaction", err)
-	}
-	return nil
-}
-
-// TreapForEacher is an interface which allows iteration of a treap in ascending
-// order using a user-supplied callback for each key/value pair. It mainly
-// exists so both mutable and immutable treaps can be atomically committed to
-// the database with the same function.
-type TreapForEacher interface {
-	ForEach(func(k, v []byte) bool)
-}
-
-// commitTreaps atomically commits all of the passed pending add/update/remove
-// updates to the underlying database.
-func (c *dbCache) commitTreaps(pendingKeys, pendingRemove TreapForEacher) error {
-	// Perform all leveldb updates using an atomic transaction.
-	return c.updateDB(func(ldbTx *leveldb.Transaction) error {
-		var innerErr error
-		pendingKeys.ForEach(func(k, v []byte) bool {
-			if dbErr := ldbTx.Put(k, v, nil); dbErr != nil {
-				str := fmt.Sprintf("failed to put key %q to "+
-					"ldb transaction", k)
-				innerErr = convertErr(str, dbErr)
-				return false
-			}
-			return true
-		})
-		if innerErr != nil {
-			return innerErr
-		}
-
-		pendingRemove.ForEach(func(k, v []byte) bool {
-			if dbErr := ldbTx.Delete(k, nil); dbErr != nil {
-				str := fmt.Sprintf("failed to delete "+
-					"key %q from ldb transaction",
-					k)
-				innerErr = convertErr(str, dbErr)
-				return false
-			}
-			return true
-		})
-		return innerErr
-	})
-}
-
-// flush flushes the database cache to persistent storage. This involes syncing
-// the block store and replaying all transactions that have been applied to the
-// cache to the underlying database.
-//
-// This function MUST be called with the database write lock held.
-func (c *dbCache) flush() error {
-	c.lastFlush = time.Now()
-
-	// Sync the current write file associated with the block store. This is
-	// necessary before writing the metadata to prevent the case where the
-	// metadata contains information about a block which actually hasn't
-	// been written yet in unexpected shutdown scenarios.
-	if err := c.store.syncBlocks(); err != nil {
-		return err
-	}
-
-	// Since the cached keys to be added and removed use an immutable treap,
-	// a snapshot is simply obtaining the root of the tree under the lock
-	// which is used to atomically swap the root.
-	c.cacheLock.RLock()
-	cachedKeys := c.cachedKeys
-	cachedRemove := c.cachedRemove
-	c.cacheLock.RUnlock()
-
-	// Nothing to do if there is no data to flush.
-	if cachedKeys.Len() == 0 && cachedRemove.Len() == 0 {
-		return nil
-	}
-
-	// Perform all leveldb updates using an atomic transaction.
-	if err := c.commitTreaps(cachedKeys, cachedRemove); err != nil {
-		return err
-	}
-
-	// Clear the cache since it has been flushed.
-	c.cacheLock.Lock()
-	c.cachedKeys = treap.NewImmutable()
-	c.cachedRemove = treap.NewImmutable()
-	c.cacheLock.Unlock()
-
-	return nil
-}
-
-// needsFlush returns whether or not the database cache needs to be flushed to
-// persistent storage based on its current size, whether or not adding all of
-// the entries in the passed database transaction would cause it to exceed the
-// configured limit, and how much time has elapsed since the last time the cache
-// was flushed.
-//
-// This function MUST be called with the database write lock held.
-func (c *dbCache) needsFlush(tx *transaction) bool {
-	// A flush is needed when more time has elapsed than the configured
-	// flush interval.
-	if time.Since(c.lastFlush) >= c.flushInterval {
-		return true
-	}
-
-	// A flush is needed when the size of the database cache exceeds the
-	// specified max cache size. The total calculated size is multiplied by
-	// 1.5 here to account for additional memory consumption that will be
-	// needed during the flush as well as old nodes in the cache that are
-	// referenced by the snapshot used by the transaction.
-	snap := tx.snapshot
-	totalSize := snap.pendingKeys.Size() + snap.pendingRemove.Size()
-	totalSize = uint64(float64(totalSize) * 1.5)
-	return totalSize > c.maxSize
-}
-
-// commitTx atomically adds all of the pending keys to add and remove into the
-// database cache. When adding the pending keys would cause the size of the
-// cache to exceed the max cache size, or the time since the last flush exceeds
-// the configured flush interval, the cache will be flushed to the underlying
-// persistent database.
-//
-// This is an atomic operation with respect to the cache in that either all of
-// the pending keys to add and remove in the transaction will be applied or none
-// of them will.
-//
-// The database cache itself might be flushed to the underlying persistent
-// database even if the transaction fails to apply, but it will only be the
-// state of the cache without the transaction applied.
-//
-// This function MUST be called during a database write transaction which in
-// turn implies the database write lock will be held.
-func (c *dbCache) commitTx(tx *transaction) error {
-	// Flush the cache and write the current transaction directly to the
-	// database if a flush is needed.
-	if c.needsFlush(tx) {
-		if err := c.flush(); err != nil {
-			return err
-		}
-
-		// Perform all leveldb updates using an atomic transaction.
-		err := c.commitTreaps(tx.pendingKeys, tx.pendingRemove)
-		if err != nil {
-			return err
-		}
-
-		// Clear the transaction entries since they have been committed.
-		tx.pendingKeys = nil
-		tx.pendingRemove = nil
-		return nil
-	}
-
-	// At this point a database flush is not needed, so atomically commit
-	// the transaction to the cache.
-
-	// Since the cached keys to be added and removed use an immutable treap,
-	// a snapshot is simply obtaining the root of the tree under the lock
-	// which is used to atomically swap the root.
-	c.cacheLock.RLock()
-	newCachedKeys := c.cachedKeys
-	newCachedRemove := c.cachedRemove
-	c.cacheLock.RUnlock()
-
-	// Apply every key to add in the database transaction to the cache.
-	tx.pendingKeys.ForEach(func(k, v []byte) bool {
-		newCachedRemove = newCachedRemove.Delete(k)
-		newCachedKeys = newCachedKeys.Put(k, v)
-		return true
-	})
-	tx.pendingKeys = nil
-
-	// Apply every key to remove in the database transaction to the cache.
-	tx.pendingRemove.ForEach(func(k, v []byte) bool {
-		newCachedKeys = newCachedKeys.Delete(k)
-		newCachedRemove = newCachedRemove.Put(k, nil)
-		return true
-	})
-	tx.pendingRemove = nil
-
-	// Atomically replace the immutable treaps which hold the cached keys to
-	// add and delete.
-	c.cacheLock.Lock()
-	c.cachedKeys = newCachedKeys
-	c.cachedRemove = newCachedRemove
-	c.cacheLock.Unlock()
-	return nil
-}
-
-// Close cleanly shuts down the database cache by syncing all data and closing
-// the underlying leveldb database.
-//
-// This function MUST be called with the database write lock held.
-func (c *dbCache) Close() error {
-	// Flush any outstanding cached entries to disk.
-	if err := c.flush(); err != nil {
-		// Even if there is an error while flushing, attempt to close
-		// the underlying database. The error is ignored since it would
-		// mask the flush error.
-		_ = c.ldb.Close()
-		return err
-	}
-
-	// Close the underlying leveldb database.
-	if err := c.ldb.Close(); err != nil {
-		str := "failed to close underlying leveldb database"
-		return convertErr(str, err)
-	}
-
-	return nil
-}
-
-// newDbCache returns a new database cache instance backed by the provided
-// leveldb instance. The cache will be flushed to leveldb when the max size
-// exceeds the provided value or it has been longer than the provided interval
-// since the last flush.
-func newDbCache(ldb *leveldb.DB, store *blockStore, maxSize uint64, flushIntervalSecs uint32) *dbCache {
-	return &dbCache{
-		ldb:           ldb,
-		store:         store,
-		maxSize:       maxSize,
-		flushInterval: time.Second * time.Duration(flushIntervalSecs),
-		lastFlush:     time.Now(),
-		cachedKeys:    treap.NewImmutable(),
-		cachedRemove:  treap.NewImmutable(),
-	}
-}

database/ffldb/dbcache_test.go

@@ -1,136 +0,0 @@
-package ffldb
-
-import (
-	"bytes"
-	"testing"
-
-	"github.com/kaspanet/kaspad/database"
-	ldbutil "github.com/syndtr/goleveldb/leveldb/util"
-)
-
-func TestExhaustedDbCacheIterator(t *testing.T) {
-	db := newTestDb("TestExhaustedDbCacheIterator", t)
-	defer db.Close()
-
-	snapshot, err := db.cache.Snapshot()
-	if err != nil {
-		t.Fatalf("TestExhaustedDbCacheIterator: Error creating cache snapshot: %s", err)
-	}
-	iterator := snapshot.NewIterator(&ldbutil.Range{})
-
-	if next := iterator.Next(); next != false {
-		t.Errorf("TestExhaustedDbCacheIterator: Expected .Next() = false, but got %v", next)
-	}
-
-	if prev := iterator.Prev(); prev != false {
-		t.Errorf("TestExhaustedDbCacheIterator: Expected .Prev() = false, but got %v", prev)
-	}
-
-	if key := iterator.Key(); key != nil {
-		t.Errorf("TestExhaustedDbCacheIterator: Expected .Key() = nil, but got %v", key)
-	}
-
-	if value := iterator.Value(); value != nil {
-		t.Errorf("TestExhaustedDbCacheIterator: Expected .Value() = nil, but got %v", value)
-	}
-}
-
-// TestLDBIteratorImplPlaceholders hits functions that are there to implement leveldb iterator.Iterator interface,
-// but surve no other purpose.
-func TestLDBIteratorImplPlaceholders(t *testing.T) {
-	db := newTestDb("TestIteratorImplPlaceholders", t)
-	defer db.Close()
-
-	snapshot, err := db.cache.Snapshot()
-	if err != nil {
-		t.Fatalf("TestLDBIteratorImplPlaceholders: Error creating cache snapshot: %s", err)
-	}
-	iterator := newLdbCacheIter(snapshot, &ldbutil.Range{})
-
-	if err = iterator.Error(); err != nil {
-		t.Errorf("TestLDBIteratorImplPlaceholders: Expected .Error() = nil, but got %v", err)
-	}
-
-	// Call SetReleaser to achieve coverage of it. Actually does nothing
-	iterator.SetReleaser(nil)
-}
-
-func TestSkipPendingUpdatesCache(t *testing.T) {
-	pdb := newTestDb("TestSkipPendingUpdatesCache", t)
-	defer pdb.Close()
-
-	value := []byte("value")
-	// Add numbered prefixes to keys so that they are in expected order, and before any other keys
-	firstKey := []byte("1 - first")
-	toDeleteKey := []byte("2 - toDelete")
-	toUpdateKey := []byte("3 - toUpdate")
-	secondKey := []byte("4 - second")
-
-	// create initial metadata for test
-	err := pdb.Update(func(dbTx database.Tx) error {
-		metadata := dbTx.Metadata()
-		if err := metadata.Put(firstKey, value); err != nil {
-			return err
-		}
-		if err := metadata.Put(toDeleteKey, value); err != nil {
-			return err
-		}
-		if err := metadata.Put(toUpdateKey, value); err != nil {
-			return err
-		}
-		if err := metadata.Put(secondKey, value); err != nil {
-			return err
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("Error adding to metadata: %s", err)
-	}
-
-	err = pdb.cache.flush()
-	if err != nil {
-		t.Fatalf("Error flushing cache: %s", err)
-	}
-
-	// test skips
-	err = pdb.Update(func(dbTx database.Tx) error {
-		snapshot, err := pdb.cache.Snapshot()
-		if err != nil {
-			t.Fatalf("TestSkipPendingUpdatesCache: Error getting snapshot: %s", err)
-		}
-
-		iterator := snapshot.NewIterator(&ldbutil.Range{})
-		snapshot.pendingRemove = snapshot.pendingRemove.Put(bucketizedKey(metadataBucketID, toDeleteKey), value)
-		snapshot.pendingKeys = snapshot.pendingKeys.Put(bucketizedKey(metadataBucketID, toUpdateKey), value)
-
-		// Check that first is ok
-		iterator.First()
-		expectedKey := bucketizedKey(metadataBucketID, firstKey)
-		actualKey := iterator.Key()
-		if !bytes.Equal(actualKey, expectedKey) {
-			t.Errorf("TestSkipPendingUpdatesCache: 1: key expected to be %v but is %v", expectedKey, actualKey)
-		}
-
-		// Go to the next key, which is second, toDelete and toUpdate will be skipped
-		iterator.Next()
-		expectedKey = bucketizedKey(metadataBucketID, secondKey)
-		actualKey = iterator.Key()
-		if !bytes.Equal(actualKey, expectedKey) {
-			t.Errorf("TestSkipPendingUpdatesCache: 2: key expected to be %s but is %s", expectedKey, actualKey)
-		}
-
-		// now traverse backwards - should get first, toUpdate and toDelete will be skipped
-		iterator.Prev()
-		expectedKey = bucketizedKey(metadataBucketID, firstKey)
-		actualKey = iterator.Key()
-		if !bytes.Equal(actualKey, expectedKey) {
-			t.Errorf("TestSkipPendingUpdatesCache: 4: key expected to be %s but is %s", expectedKey, actualKey)
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Fatalf("TestSkipPendingUpdatesCache: Error running main part of test: %s", err)
-	}
-}

database/ffldb/doc.go

@@ -1,25 +0,0 @@
-/*
-Package ffldb implements a driver for the database package that uses leveldb
-for the backing metadata and flat files for block storage.
-
-This driver is the recommended driver for use with kaspad. It makes use leveldb
-for the metadata, flat files for block storage, and checksums in key areas to
-ensure data integrity.
-
-Usage
-
-This package is a driver to the database package and provides the database type
-of "ffldb". The parameters the Open and Create functions take are the
-database path as a string and the block network:
-
-	db, err := database.Open("ffldb", "path/to/database", wire.Mainnet)
-	if err != nil {
-		// Handle error
-	}
-
-	db, err := database.Create("ffldb", "path/to/database", wire.Mainnet)
-	if err != nil {
-		// Handle error
-	}
-*/
-package ffldb

database/ffldb/driver.go

@@ -1,60 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package ffldb
-
-import (
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/wire"
-	"github.com/pkg/errors"
-)
-
-const (
-	dbType = "ffldb"
-)
-
-// parseArgs parses the arguments from the database Open/Create methods.
-func parseArgs(funcName string, args ...interface{}) (string, wire.KaspaNet, error) {
-	if len(args) != 2 {
-		return "", 0, errors.Errorf("invalid arguments to %s.%s -- "+
-			"expected database path and block network", dbType,
-			funcName)
-	}
-
-	dbPath, ok := args[0].(string)
-	if !ok {
-		return "", 0, errors.Errorf("first argument to %s.%s is invalid -- "+
-			"expected database path string", dbType, funcName)
-	}
-
-	network, ok := args[1].(wire.KaspaNet)
-	if !ok {
-		return "", 0, errors.Errorf("second argument to %s.%s is invalid -- "+
-			"expected block network", dbType, funcName)
-	}
-
-	return dbPath, network, nil
-}
-
-// openDBDriver is the callback provided during driver registration that opens
-// an existing database for use.
-func openDBDriver(args ...interface{}) (database.DB, error) {
-	dbPath, network, err := parseArgs("Open", args...)
-	if err != nil {
-		return nil, err
-	}
-
-	return openDB(dbPath, network, false)
-}
-
-// createDBDriver is the callback provided during driver registration that
-// creates, initializes, and opens a database for use.
-func createDBDriver(args ...interface{}) (database.DB, error) {
-	dbPath, network, err := parseArgs("Create", args...)
-	if err != nil {
-		return nil, err
-	}
-
-	return openDB(dbPath, network, true)
-}

database/ffldb/driver_test.go

@@ -1,290 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-package ffldb_test
-
-import (
-	"github.com/pkg/errors"
-	"os"
-	"path/filepath"
-	"reflect"
-	"runtime"
-	"testing"
-
-	"github.com/kaspanet/kaspad/dagconfig"
-	"github.com/kaspanet/kaspad/database"
-	"github.com/kaspanet/kaspad/database/ffldb"
-	"github.com/kaspanet/kaspad/util"
-)
-
-// dbType is the database type name for this driver.
-const dbType = "ffldb"
-
-// TestCreateOpenFail ensures that errors related to creating and opening a
-// database are handled properly.
-func TestCreateOpenFail(t *testing.T) {
-	t.Parallel()
-
-	// Ensure that attempting to open a database that doesn't exist returns
-	// the expected error.
-	wantErrCode := database.ErrDbDoesNotExist
-	_, err := database.Open(dbType, "noexist", blockDataNet)
-	if !checkDbError(t, "Open", err, wantErrCode) {
-		return
-	}
-
-	// Ensure that attempting to open a database with the wrong number of
-	// parameters returns the expected error.
-	wantErr := errors.Errorf("invalid arguments to %s.Open -- expected "+
-		"database path and block network", dbType)
-	_, err = database.Open(dbType, 1, 2, 3)
-	if err.Error() != wantErr.Error() {
-		t.Errorf("Open: did not receive expected error - got %v, "+
-			"want %v", err, wantErr)
-		return
-	}
-
-	// Ensure that attempting to open a database with an invalid type for
-	// the first parameter returns the expected error.
-	wantErr = errors.Errorf("first argument to %s.Open is invalid -- "+
-		"expected database path string", dbType)
-	_, err = database.Open(dbType, 1, blockDataNet)
-	if err.Error() != wantErr.Error() {
-		t.Errorf("Open: did not receive expected error - got %v, "+
-			"want %v", err, wantErr)
-		return
-	}
-
-	// Ensure that attempting to open a database with an invalid type for
-	// the second parameter returns the expected error.
-	wantErr = errors.Errorf("second argument to %s.Open is invalid -- "+
-		"expected block network", dbType)
-	_, err = database.Open(dbType, "noexist", "invalid")
-	if err.Error() != wantErr.Error() {
-		t.Errorf("Open: did not receive expected error - got %v, "+
-			"want %v", err, wantErr)
-		return
-	}
-
-	// Ensure that attempting to create a database with the wrong number of
-	// parameters returns the expected error.
-	wantErr = errors.Errorf("invalid arguments to %s.Create -- expected "+
-		"database path and block network", dbType)
-	_, err = database.Create(dbType, 1, 2, 3)
-	if err.Error() != wantErr.Error() {
-		t.Errorf("Create: did not receive expected error - got %v, "+
-			"want %v", err, wantErr)
-		return
-	}
-
-	// Ensure that attempting to create a database with an invalid type for
-	// the first parameter returns the expected error.
-	wantErr = errors.Errorf("first argument to %s.Create is invalid -- "+
-		"expected database path string", dbType)
-	_, err = database.Create(dbType, 1, blockDataNet)
-	if err.Error() != wantErr.Error() {
-		t.Errorf("Create: did not receive expected error - got %v, "+
-			"want %v", err, wantErr)
-		return
-	}
-
-	// Ensure that attempting to create a database with an invalid type for
-	// the second parameter returns the expected error.
-	wantErr = errors.Errorf("second argument to %s.Create is invalid -- "+
-		"expected block network", dbType)
-	_, err = database.Create(dbType, "noexist", "invalid")
-	if err.Error() != wantErr.Error() {
-		t.Errorf("Create: did not receive expected error - got %v, "+
-			"want %v", err, wantErr)
-		return
-	}
-
-	// Ensure operations against a closed database return the expected
-	// error.
-	dbPath := filepath.Join(os.TempDir(), "ffldb-createfail")
-	_ = os.RemoveAll(dbPath)
-	db, err := database.Create(dbType, dbPath, blockDataNet)
-	if err != nil {
-		t.Errorf("Create: unexpected error: %v", err)
-		return
-	}
-	defer os.RemoveAll(dbPath)
-	db.Close()
-
-	wantErrCode = database.ErrDbNotOpen
-	err = db.View(func(dbTx database.Tx) error {
-		return nil
-	})
-	if !checkDbError(t, "View", err, wantErrCode) {
-		return
-	}
-
-	wantErrCode = database.ErrDbNotOpen
-	err = db.Update(func(dbTx database.Tx) error {
-		return nil
-	})
-	if !checkDbError(t, "Update", err, wantErrCode) {
-		return
-	}
-
-	wantErrCode = database.ErrDbNotOpen
-	_, err = db.Begin(false)
-	if !checkDbError(t, "Begin(false)", err, wantErrCode) {
-		return
-	}
-
-	wantErrCode = database.ErrDbNotOpen
-	_, err = db.Begin(true)
-	if !checkDbError(t, "Begin(true)", err, wantErrCode) {
-		return
-	}
-
-	wantErrCode = database.ErrDbNotOpen
-	err = db.Close()
-	if !checkDbError(t, "Close", err, wantErrCode) {
-		return
-	}
-}
-
-// TestPersistence ensures that values stored are still valid after closing and
-// reopening the database.
-func TestPersistence(t *testing.T) {
-	t.Parallel()
-
-	// Create a new database to run tests against.
-	dbPath := filepath.Join(os.TempDir(), "ffldb-persistencetest")
-	_ = os.RemoveAll(dbPath)
-	db, err := database.Create(dbType, dbPath, blockDataNet)
-	if err != nil {
-		t.Errorf("Failed to create test database (%s) %v", dbType, err)
-		return
-	}
-	defer os.RemoveAll(dbPath)
-	defer db.Close()
-
-	// Create a bucket, put some values into it, and store a block so they
-	// can be tested for existence on re-open.
-	bucket1Key := []byte("bucket1")
-	storeValues := map[string]string{
-		"b1key1": "foo1",
-		"b1key2": "foo2",
-		"b1key3": "foo3",
-	}
-	genesisBlock := util.NewBlock(dagconfig.MainnetParams.GenesisBlock)
-	genesisHash := dagconfig.MainnetParams.GenesisHash
-	err = db.Update(func(dbTx database.Tx) error {
-		metadataBucket := dbTx.Metadata()
-		if metadataBucket == nil {
-			return errors.Errorf("Metadata: unexpected nil bucket")
-		}
-
-		bucket1, err := metadataBucket.CreateBucket(bucket1Key)
-		if err != nil {
-			return errors.Errorf("CreateBucket: unexpected error: %v",
-				err)
-		}
-
-		for k, v := range storeValues {
-			err := bucket1.Put([]byte(k), []byte(v))
-			if err != nil {
-				return errors.Errorf("Put: unexpected error: %v",
-					err)
-			}
-		}
-
-		if err := dbTx.StoreBlock(genesisBlock); err != nil {
-			return errors.Errorf("StoreBlock: unexpected error: %v",
-				err)
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Errorf("Update: unexpected error: %v", err)
-		return
-	}
-
-	// Close and reopen the database to ensure the values persist.
-	db.Close()
-	db, err = database.Open(dbType, dbPath, blockDataNet)
-	if err != nil {
-		t.Errorf("Failed to open test database (%s) %v", dbType, err)
-		return
-	}
-	defer db.Close()
-
-	// Ensure the values previously stored in the 3rd namespace still exist
-	// and are correct.
-	err = db.View(func(dbTx database.Tx) error {
-		metadataBucket := dbTx.Metadata()
-		if metadataBucket == nil {
-			return errors.Errorf("Metadata: unexpected nil bucket")
-		}
-
-		bucket1 := metadataBucket.Bucket(bucket1Key)
-		if bucket1 == nil {
-			return errors.Errorf("Bucket1: unexpected nil bucket")
-		}
-
-		for k, v := range storeValues {
-			gotVal := bucket1.Get([]byte(k))
-			if !reflect.DeepEqual(gotVal, []byte(v)) {
-				return errors.Errorf("Get: key '%s' does not "+
-					"match expected value - got %s, want %s",
-					k, gotVal, v)
-			}
-		}
-
-		genesisBlockBytes, _ := genesisBlock.Bytes()
-		gotBytes, err := dbTx.FetchBlock(genesisHash)
-		if err != nil {
-			return errors.Errorf("FetchBlock: unexpected error: %v",
-				err)
-		}
-		if !reflect.DeepEqual(gotBytes, genesisBlockBytes) {
-			return errors.Errorf("FetchBlock: stored block mismatch")
-		}
-
-		return nil
-	})
-	if err != nil {
-		t.Errorf("View: unexpected error: %v", err)
-		return
-	}
-}
-
-// TestInterface performs all interfaces tests for this database driver.
-func TestInterface(t *testing.T) {
-	t.Parallel()
-
-	// Create a new database to run tests against.
-	dbPath := filepath.Join(os.TempDir(), "ffldb-interfacetest")
-	_ = os.RemoveAll(dbPath)
-	db, err := database.Create(dbType, dbPath, blockDataNet)
-	if err != nil {
-		t.Errorf("Failed to create test database (%s) %v", dbType, err)
-		return
-	}
-	defer os.RemoveAll(dbPath)
-	defer db.Close()
-
-	// Ensure the driver type is the expected value.
-	gotDbType := db.Type()
-	if gotDbType != dbType {
-		t.Errorf("Type: unepxected driver type - got %v, want %v",
-			gotDbType, dbType)
-		return
-	}
-
-	// Run all of the interface tests against the database.
-	runtime.GOMAXPROCS(runtime.NumCPU())
-
-	// Change the maximum file size to a small value to force multiple flat
-	// files with the test data set.
-	// Change maximum open files to small value to force shifts in the LRU
-	// mechanism
-	ffldb.TstRunWithMaxBlockFileSizeAndMaxOpenFiles(db, 2048, 10, func() {
-		testInterface(t, db)
-	})
-}

database/ffldb/export_test.go

@@ -1,29 +0,0 @@
-// Copyright (c) 2015-2016 The btcsuite developers
-// Use of this source code is governed by an ISC
-// license that can be found in the LICENSE file.
-
-/*
-This test file is part of the ffldb package rather than than the ffldb_test
-package so it can bridge access to the internals to properly test cases which
-are either not possible or can't reliably be tested via the public interface.
-The functions are only exported while the tests are being run.
-*/
-
-package ffldb
-
-import "github.com/kaspanet/kaspad/database"
-
-// TstRunWithMaxBlockFileSize runs the passed function with the maximum allowed
-// file size for the database set to the provided value. The value will be set
-// back to the original value upon completion.
-func TstRunWithMaxBlockFileSizeAndMaxOpenFiles(idb database.DB, size uint32, maxOpenFiles int, fn func()) {
-	ffldb := idb.(*db)
-	origSize := ffldb.store.maxBlockFileSize
-	origMaxOpenFiles := ffldb.store.maxOpenFiles
-
-	ffldb.store.maxBlockFileSize = size
-	ffldb.store.maxOpenFiles = maxOpenFiles
-	fn()
-	ffldb.store.maxBlockFileSize = origSize
-	ffldb.store.maxOpenFiles = origMaxOpenFiles
-}

database/ffldb/ff/flatfile.go

@@ -0,0 +1,229 @@
+package ff
+
+import (
+	"container/list"
+	"encoding/binary"
+	"fmt"
+	"github.com/pkg/errors"
+	"hash/crc32"
+	"os"
+	"path/filepath"
+	"sync"
+)
+
+const (
+	// maxOpenFiles is the max number of open files to maintain in each store's
+	// cache. Note that this does not include the current/write file, so there
+	// will typically be one more than this value open.
+	maxOpenFiles = 25
+
+	// maxFileSize is the maximum size for each file used to store data.
+	//
+	// NOTE: The current code uses uint32 for all offsets, so this value
+	// must be less than 2^32 (4 GiB). This is also why it's a typed
+	// constant.
+	maxFileSize uint32 = 512 * 1024 * 1024 // 512 MiB
+)
+
+var (
+	// byteOrder is the preferred byte order used through the flat files.
+	// Sometimes big endian will be used to allow ordered byte sortable
+	// integer values.
+	byteOrder = binary.LittleEndian
+
+	// crc32ByteOrder is the byte order used for CRC-32 checksums.
+	crc32ByteOrder = binary.BigEndian
+
+	// crc32ChecksumLength is the length in bytes of a CRC-32 checksum.
+	crc32ChecksumLength = 4
+
+	// dataLengthLength is the length in bytes of the "data length" section
+	// of a serialized entry in a flat file store.
+	dataLengthLength = 4
+
+	// castagnoli houses the Catagnoli polynomial used for CRC-32 checksums.
+	castagnoli = crc32.MakeTable(crc32.Castagnoli)
+)
+
+// flatFileStore houses information used to handle reading and writing data
+// into flat files with support for multiple concurrent readers.
+type flatFileStore struct {
+	// basePath is the base path used for the flat files.
+	basePath string
+
+	// storeName is the name of this flat-file store.
+	storeName string
+
+	// The following fields are related to the flat files which hold the
+	// actual data. The number of open files is limited by maxOpenFiles.
+	//
+	// openFilesMutex protects concurrent access to the openFiles map. It
+	// is a RWMutex so multiple readers can simultaneously access open
+	// files.
+	//
+	// openFiles houses the open file handles for existing files which have
+	// been opened read-only along with an individual RWMutex. This scheme
+	// allows multiple concurrent readers to the same file while preventing
+	// the file from being closed out from under them.
+	//
+	// lruMutex protects concurrent access to the least recently used list
+	// and lookup map.
+	//
+	// openFilesLRU tracks how the open files are referenced by pushing the
+	// most recently used files to the front of the list thereby trickling
+	// the least recently used files to end of the list. When a file needs
+	// to be closed due to exceeding the max number of allowed open
+	// files, the one at the end of the list is closed.
+	//
+	// fileNumberToLRUElement is a mapping between a specific file number and
+	// the associated list element on the least recently used list.
+	//
+	// Thus, with the combination of these fields, the database supports
+	// concurrent non-blocking reads across multiple and individual files
+	// along with intelligently limiting the number of open file handles by
+	// closing the least recently used files as needed.
+	//
+	// NOTE: The locking order used throughout is well-defined and MUST be
+	// followed. Failure to do so could lead to deadlocks. In particular,
+	// the locking order is as follows:
+	//   1) openFilesMutex
+	//   2) lruMutex
+	//   3) writeCursor mutex
+	//   4) specific file mutexes
+	//
+	// None of the mutexes are required to be locked at the same time, and
+	// often aren't. However, if they are to be locked simultaneously, they
+	// MUST be locked in the order previously specified.
+	//
+	// Due to the high performance and multi-read concurrency requirements,
+	// write locks should only be held for the minimum time necessary.
+	openFilesMutex         sync.RWMutex
+	openFiles              map[uint32]*lockableFile
+	lruMutex               sync.Mutex
+	openFilesLRU           *list.List // Contains uint32 file numbers.
+	fileNumberToLRUElement map[uint32]*list.Element
+
+	// writeCursor houses the state for the current file and location that
+	// new data is written to.
+	writeCursor *writeCursor
+
+	// isClosed is true when the store is closed. Any operations on a closed
+	// store will fail.
+	isClosed bool
+}
+
+// writeCursor represents the current file and offset of the flat file on disk
+// for performing all writes. It also contains a read-write mutex to support
+// multiple concurrent readers which can reuse the file handle.
+type writeCursor struct {
+	sync.RWMutex
+
+	// currentFile is the current file that will be appended to when writing
+	// new data.
+	currentFile *lockableFile
+
+	// currentFileNumber is the current file number and is used to allow
+	// readers to use the same open file handle.
+	currentFileNumber uint32
+
+	// currentOffset is the offset in the current file where the next new
+	// data will be written.
+	currentOffset uint32
+}
+
+// openFlatFileStore returns a new flat file store with the current file number
+// and offset set and all fields initialized.
+func openFlatFileStore(basePath string, storeName string) (*flatFileStore, error) {
+	// Look for the end of the latest file to determine what the write cursor
+	// position is from the viewpoint of the flat files on disk.
+	fileNumber, fileOffset, err := findCurrentLocation(basePath, storeName)
+	if err != nil {
+		return nil, err
+	}
+
+	store := &flatFileStore{
+		basePath:               basePath,
+		storeName:              storeName,
+		openFiles:              make(map[uint32]*lockableFile),
+		openFilesLRU:           list.New(),
+		fileNumberToLRUElement: make(map[uint32]*list.Element),
+		writeCursor: &writeCursor{
+			currentFile:       &lockableFile{},
+			currentFileNumber: fileNumber,
+			currentOffset:     fileOffset,
+		},
+		isClosed: false,
+	}
+	return store, nil
+}
+
+func (s *flatFileStore) Close() error {
+	if s.isClosed {
+		return errors.Errorf("cannot close a closed store %s",
+			s.storeName)
+	}
+	s.isClosed = true
+
+	// Close the write cursor. We lock the write cursor here
+	// to let it finish any undergoing writing.
+	s.writeCursor.Lock()
+	defer s.writeCursor.Unlock()
+	err := s.writeCursor.currentFile.Close()
+	if err != nil {
+		return err
+	}
+
+	// Close all open files
+	for _, openFile := range s.openFiles {
+		err := openFile.Close()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *flatFileStore) currentLocation() *flatFileLocation {
+	return &flatFileLocation{
+		fileNumber: s.writeCursor.currentFileNumber,
+		fileOffset: s.writeCursor.currentOffset,
+		dataLength: 0,
+	}
+}
+
+// findCurrentLocation searches the database directory for all flat files for a given
+// store to find the end of the most recent file. This position is considered
+// the current write cursor.
+func findCurrentLocation(dbPath string, storeName string) (fileNumber uint32, fileLength uint32, err error) {
+	currentFileNumber := uint32(0)
+	currentFileLength := uint32(0)
+	for {
+		currentFilePath := flatFilePath(dbPath, storeName, currentFileNumber)
+		stat, err := os.Stat(currentFilePath)
+		if err != nil {
+			if !os.IsNotExist(err) {
+				return 0, 0, errors.WithStack(err)
+			}
+			if currentFileNumber > 0 {
+				fileNumber = currentFileNumber - 1
+			}
+			fileLength = currentFileLength
+			break
+		}
+		currentFileLength = uint32(stat.Size())
+		currentFileNumber++
+	}
+
+	log.Tracef("Scan for store '%s' found latest file #%d with length %d",
+		storeName, fileNumber, fileLength)
+	return fileNumber, fileLength, nil
+}
+
+// flatFilePath return the file path for the provided store's flat file number.
+func flatFilePath(dbPath string, storeName string, fileNumber uint32) string {
+	// Choose 9 digits of precision for the filenames. 9 digits provide
+	// 10^9 files @ 512MiB each a total of ~476.84PiB.
+
+	fileName := fmt.Sprintf("%s-%09d.fdb", storeName, fileNumber)
+	return filepath.Join(dbPath, fileName)
+}

database/ffldb/ff/flatfile_test.go

@@ -0,0 +1,74 @@
+package ff
+
+import (
+	"io/ioutil"
+	"reflect"
+	"testing"
+)
+
+func TestFlatFileStoreSanity(t *testing.T) {
+	// Open a test store
+	path, err := ioutil.TempDir("", "TestFlatFileStoreSanity")
+	if err != nil {
+		t.Fatalf("TestFlatFileStoreSanity: TempDir unexpectedly "+
+			"failed: %s", err)
+	}
+	name := "test"
+	store, err := openFlatFileStore(path, name)
+	if err != nil {
+		t.Fatalf("TestFlatFileStoreSanity: openFlatFileStore "+
+			"unexpectedly failed: %s", err)
+	}
+
+	// Write something to the store
+	writeData := []byte("Hello world!")
+	location, err := store.write(writeData)
+	if err != nil {
+		t.Fatalf("TestFlatFileStoreSanity: Write returned "+
+			"unexpected error: %s", err)
+	}
+
+	// Read from the location previously written to
+	readData, err := store.read(location)
+	if err != nil {
+		t.Fatalf("TestFlatFileStoreSanity: read returned "+
+			"unexpected error: %s", err)
+	}
+
+	// Make sure that the written data and the read data are equal
+	if !reflect.DeepEqual(readData, writeData) {
+		t.Fatalf("TestFlatFileStoreSanity: read data and "+
+			"write data are not equal. Wrote: %s, read: %s",
+			string(writeData), string(readData))
+	}
+}
+
+func TestFlatFilePath(t *testing.T) {
+	tests := []struct {
+		dbPath       string
+		storeName    string
+		fileNumber   uint32
+		expectedPath string
+	}{
+		{
+			dbPath:       "path",
+			storeName:    "store",
+			fileNumber:   0,
+			expectedPath: "path/store-000000000.fdb",
+		},
+		{
+			dbPath:       "path/to/database",
+			storeName:    "blocks",
+			fileNumber:   123456789,
+			expectedPath: "path/to/database/blocks-123456789.fdb",
+		},
+	}
+
+	for _, test := range tests {
+		path := flatFilePath(test.dbPath, test.storeName, test.fileNumber)
+		if path != test.expectedPath {
+			t.Errorf("TestFlatFilePath: unexpected path. Want: %s, got: %s",
+				test.expectedPath, path)
+		}
+	}
+}

database/ffldb/ff/flatfiledb.go

@@ -0,0 +1,103 @@
+package ff
+
+// FlatFileDB is a flat-file database. It supports opening
+// multiple flat-file stores. See flatFileStore for further
+// details.
+type FlatFileDB struct {
+	path           string
+	flatFileStores map[string]*flatFileStore
+}
+
+// NewFlatFileDB opens the flat-file database defined by
+// the given path.
+func NewFlatFileDB(path string) *FlatFileDB {
+	return &FlatFileDB{
+		path:           path,
+		flatFileStores: make(map[string]*flatFileStore),
+	}
+}
+
+// Close closes the flat-file database.
+func (ffdb *FlatFileDB) Close() error {
+	for _, store := range ffdb.flatFileStores {
+		err := store.Close()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Write appends the specified data bytes to the specified store.
+// It returns a serialized location handle that's meant to be
+// stored and later used when querying the data that has just now
+// been inserted.
+// See flatFileStore.write() for further details.
+func (ffdb *FlatFileDB) Write(storeName string, data []byte) ([]byte, error) {
+	store, err := ffdb.store(storeName)
+	if err != nil {
+		return nil, err
+	}
+	location, err := store.write(data)
+	if err != nil {
+		return nil, err
+	}
+	return serializeLocation(location), nil
+}
+
+// Read reads data from the specified flat file store at the
+// location specified by the given serialized location handle.
+// It returns ErrNotFound if the location does not exist.
+// See flatFileStore.read() for further details.
+func (ffdb *FlatFileDB) Read(storeName string, serializedLocation []byte) ([]byte, error) {
+	store, err := ffdb.store(storeName)
+	if err != nil {
+		return nil, err
+	}
+	location, err := deserializeLocation(serializedLocation)
+	if err != nil {
+		return nil, err
+	}
+	return store.read(location)
+}
+
+// CurrentLocation returns the serialized location handle to
+// the current location within the flat file store defined
+// storeName. It is mainly to be used to rollback flat-file
+// stores in case of data incongruency.
+func (ffdb *FlatFileDB) CurrentLocation(storeName string) ([]byte, error) {
+	store, err := ffdb.store(storeName)
+	if err != nil {
+		return nil, err
+	}
+	currentLocation := store.currentLocation()
+	return serializeLocation(currentLocation), nil
+}
+
+// Rollback truncates the flat-file store defined by the given
+// storeName to the location defined by the given serialized
+// location handle.
+func (ffdb *FlatFileDB) Rollback(storeName string, serializedLocation []byte) error {
+	store, err := ffdb.store(storeName)
+	if err != nil {
+		return err
+	}
+	location, err := deserializeLocation(serializedLocation)
+	if err != nil {
+		return err
+	}
+	return store.rollback(location)
+}
+
+func (ffdb *FlatFileDB) store(storeName string) (*flatFileStore, error) {
+	store, ok := ffdb.flatFileStores[storeName]
+	if !ok {
+		var err error
+		store, err = openFlatFileStore(ffdb.path, storeName)
+		if err != nil {
+			return nil, err
+		}
+		ffdb.flatFileStores[storeName] = store
+	}
+	return store, nil
+}

database/ffldb/ff/location.go

@@ -0,0 +1,44 @@
+package ff
+
+import "github.com/pkg/errors"
+
+// flatFileLocationSerializedSize is the size in bytes of a serialized flat
+// file location. See serializeLocation for further details.
+const flatFileLocationSerializedSize = 12
+
+// flatFileLocation identifies a particular flat file location.
+type flatFileLocation struct {
+	fileNumber uint32
+	fileOffset uint32
+	dataLength uint32
+}
+
+// serializeLocation returns the serialization of the passed flat file location
+// of certain data. This to later on be used for retrieval of said data.
+// The serialized location format is:
+//
+//  [0:4]  File Number (4 bytes)
+//  [4:8]  File offset (4 bytes)
+//  [8:12] Data length (4 bytes)
+func serializeLocation(location *flatFileLocation) []byte {
+	var serializedLocation [flatFileLocationSerializedSize]byte
+	byteOrder.PutUint32(serializedLocation[0:4], location.fileNumber)
+	byteOrder.PutUint32(serializedLocation[4:8], location.fileOffset)
+	byteOrder.PutUint32(serializedLocation[8:12], location.dataLength)
+	return serializedLocation[:]
+}
+
+// deserializeLocation deserializes the passed serialized flat file location.
+// See serializeLocation for further details.
+func deserializeLocation(serializedLocation []byte) (*flatFileLocation, error) {
+	if len(serializedLocation) != flatFileLocationSerializedSize {
+		return nil, errors.Errorf("unexpected serializedLocation length: %d",
+			len(serializedLocation))
+	}
+	location := &flatFileLocation{
+		fileNumber: byteOrder.Uint32(serializedLocation[0:4]),
+		fileOffset: byteOrder.Uint32(serializedLocation[4:8]),
+		dataLength: byteOrder.Uint32(serializedLocation[8:12]),
+	}
+	return location, nil
+}