[NOD-629] change GHOSTDAG k to uint8 (#594)

* [NOD-629] Change GHOSTDAG K to a a single byte using type

* [NOD-629] Rename variable

* [NOD-629] Rename K to KSize

* [NOD-629] Remove redundant casting

* [NOD-629] Add test for KSize

* [NOD-629] Seperate block serialization and db store

* [NOD-629] Make sure K is serialized as uint8

* [NOD-629] Rename KSize to KType

* [NOD-629] Comment for test

* [NOD-629] Change fail message

* [NOD-629] Remove newlines

* [NOD-629] Fix test

* [NOD-629] Do not use maxuint8, but !0 instead

* [NOD-629] Fix test

* [NOD-629] Merge conflict

* [NOD-629] Fix test; Update comment

blockdag/blocknode.go

@@ -6,6 +6,7 @@ package blockdag
 
 import (
 	"fmt"
+	"github.com/kaspanet/kaspad/dagconfig"
 	"github.com/pkg/errors"
 	"math"
 	"time"
@@ -79,7 +80,7 @@ type blockNode struct {
 
 	// bluesAnticoneSizes is a map holding the set of blues affected by this block and their
 	// modified blue anticone size.
-	bluesAnticoneSizes map[daghash.Hash]uint32
+	bluesAnticoneSizes map[daghash.Hash]dagconfig.KType
 
 	// hash is the double sha 256 of the block.
 	hash *daghash.Hash
@@ -115,7 +116,7 @@ func (dag *BlockDAG) newBlockNode(blockHeader *wire.BlockHeader, parents blockSe
 		children:           make(blockSet),
 		blueScore:          math.MaxUint64, // Initialized to the max value to avoid collisions with the genesis block
 		timestamp:          dag.AdjustedTime().Unix(),
-		bluesAnticoneSizes: make(map[daghash.Hash]uint32),
+		bluesAnticoneSizes: make(map[daghash.Hash]dagconfig.KType),
 	}
 
 	// blockHeader is nil only for the virtual block

blockdag/blocknode_test.go

@@ -0,0 +1,40 @@
+package blockdag
+
+import (
+	"github.com/kaspanet/kaspad/dagconfig"
+	"github.com/kaspanet/kaspad/util/daghash"
+	"testing"
+)
+
+// 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{
+		DAGParams: &dagconfig.SimnetParams,
+	})
+	if err != nil {
+		t.Fatalf("TestBlueAnticoneSizesSize: Failed to setup DAG instance: %s", err)
+	}
+	defer teardownFunc()
+
+	k := dagconfig.KType(0)
+	k--
+
+	if k < dagconfig.KType(0) {
+		t.Fatalf("KType must be unsigned")
+	}
+
+	blockHeader := dagconfig.SimnetParams.GenesisBlock.Header
+	node, _ := dag.newBlockNode(&blockHeader, newSet())
+	hash := daghash.Hash{1}
+	// Setting maxKType to maximum value of KType.
+	// As we verify above that KType is unsigned we can be sure that maxKType is indeed the maximum value of KType.
+	maxKType := ^dagconfig.KType(0)
+	node.bluesAnticoneSizes[hash] = maxKType
+	serializedNode, _ := serializeBlockNode(node)
+	deserializedNode, _ := dag.deserializeBlockNode(serializedNode)
+	if deserializedNode.bluesAnticoneSizes[hash] != maxKType {
+		t.Fatalf("TestBlueAnticoneSizesSize: BlueAnticoneSize should not change when deserializing. Expected: %v but got %v",
+			maxKType, deserializedNode.bluesAnticoneSizes[hash])
+	}
+}

blockdag/dagio.go

@@ -9,6 +9,7 @@ import (
 	"encoding/binary"
 	"encoding/json"
 	"fmt"
+	"github.com/kaspanet/kaspad/dagconfig"
 	"github.com/pkg/errors"
 	"io"
 	"sync"
@@ -705,13 +706,14 @@ func (dag *BlockDAG) deserializeBlockNode(blockRow []byte) (*blockNode, error) {
 		return nil, err
 	}
 
-	node.bluesAnticoneSizes = make(map[daghash.Hash]uint32)
+	node.bluesAnticoneSizes = make(map[daghash.Hash]dagconfig.KType)
 	for i := uint64(0); i < bluesAnticoneSizesLen; i++ {
 		hash := &daghash.Hash{}
 		if _, err := io.ReadFull(buffer, hash[:]); err != nil {
 			return nil, err
 		}
-		node.bluesAnticoneSizes[*hash], err = binaryserializer.Uint32(buffer, byteOrder)
+		bluesAnticoneSize, err := binaryserializer.Uint8(buffer)
+		node.bluesAnticoneSizes[*hash] = dagconfig.KType(bluesAnticoneSize)
 		if err != nil {
 			return nil, err
 		}
@@ -738,20 +740,17 @@ func dbFetchBlockByNode(dbTx database.Tx, node *blockNode) (*util.Block, error)
 	return block, 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 {
-	// Serialize block data to be stored.
+func serializeBlockNode(node *blockNode) ([]byte, error) {
 	w := bytes.NewBuffer(make([]byte, 0, blockHdrSize+1))
 	header := node.Header()
 	err := header.Serialize(w)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	err = w.WriteByte(byte(node.status))
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	// Because genesis doesn't have selected parent, it's serialized as zero hash
@@ -761,48 +760,55 @@ func dbStoreBlockNode(dbTx database.Tx, node *blockNode) error {
 	}
 	_, err = w.Write(selectedParentHash[:])
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	err = binaryserializer.PutUint64(w, byteOrder, node.blueScore)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	err = wire.WriteVarInt(w, uint64(len(node.blues)))
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	for _, blue := range node.blues {
 		_, err = w.Write(blue.hash[:])
 		if err != nil {
-			return err
+			return nil, err
 		}
 	}
 
 	err = wire.WriteVarInt(w, uint64(len(node.bluesAnticoneSizes)))
 	if err != nil {
-		return err
+		return nil, err
 	}
 	for blockHash, blueAnticoneSize := range node.bluesAnticoneSizes {
 		_, err = w.Write(blockHash[:])
 		if err != nil {
-			return err
+			return nil, err
 		}
 
-		err = binaryserializer.PutUint32(w, byteOrder, blueAnticoneSize)
+		err = binaryserializer.PutUint8(w, uint8(blueAnticoneSize))
 		if err != nil {
-			return err
+			return nil, err
 		}
 	}
+	return w.Bytes(), nil
+}
 
-	value := w.Bytes()
-
+// 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, value)
+	return blockIndexBucket.Put(key, serializedNode)
 }
 
 // dbStoreBlock stores the provided block in the database if it is not already

blockdag/external_dag_test.go

@@ -320,7 +320,7 @@ func TestChainedTransactions(t *testing.T) {
 func TestOrderInDiffFromAcceptanceData(t *testing.T) {
 	// Create a new database and DAG instance to run tests against.
 	params := dagconfig.SimnetParams
-	params.K = math.MaxUint32
+	params.K = math.MaxUint8
 	dag, teardownFunc, err := blockdag.DAGSetup("TestOrderInDiffFromAcceptanceData", blockdag.Config{
 		DAGParams: &params,
 	})

blockdag/ghostdag.go

@@ -1,6 +1,7 @@
 package blockdag
 
 import (
+	"github.com/kaspanet/kaspad/dagconfig"
 	"github.com/pkg/errors"
 	"sort"
 )
@@ -38,8 +39,8 @@ func (dag *BlockDAG) ghostdag(newNode *blockNode) (selectedParentAnticone []*blo
 	})
 
 	for _, blueCandidate := range selectedParentAnticone {
-		candidateBluesAnticoneSizes := make(map[*blockNode]uint32)
-		var candidateAnticoneSize uint32
+		candidateBluesAnticoneSizes := make(map[*blockNode]dagconfig.KType)
+		var candidateAnticoneSize dagconfig.KType
 		possiblyBlue := true
 
 		// Iterate over all blocks in the blue set of newNode that are not in the past
@@ -108,7 +109,7 @@ func (dag *BlockDAG) ghostdag(newNode *blockNode) (selectedParentAnticone []*blo
 
 			// The maximum length of node.blues can be K+1 because
 			// it contains the selected parent.
-			if uint32(len(newNode.blues)) == dag.dagParams.K+1 {
+			if dagconfig.KType(len(newNode.blues)) == dag.dagParams.K+1 {
 				break
 			}
 		}
@@ -165,7 +166,7 @@ func (dag *BlockDAG) selectedParentAnticone(node *blockNode) ([]*blockNode, erro
 
 // blueAnticoneSize returns the blue anticone size of 'block' from the worldview of 'context'.
 // Expects 'block' to be in the blue set of 'context'
-func (dag *BlockDAG) blueAnticoneSize(block, context *blockNode) (uint32, error) {
+func (dag *BlockDAG) blueAnticoneSize(block, context *blockNode) (dagconfig.KType, error) {
 	for current := context; current != nil; current = current.selectedParent {
 		if blueAnticoneSize, ok := current.bluesAnticoneSizes[*block.hash]; ok {
 			return blueAnticoneSize, nil

blockdag/ghostdag_test.go

@@ -24,7 +24,7 @@ func TestGHOSTDAG(t *testing.T) {
 	dagParams := dagconfig.SimnetParams
 
 	tests := []struct {
-		k            uint32
+		k            dagconfig.KType
 		expectedReds []string
 		dagData      []*testBlockData
 	}{

blockdag/process.go

@@ -6,6 +6,7 @@ package blockdag
 
 import (
 	"fmt"
+	"github.com/kaspanet/kaspad/dagconfig"
 	"time"
 
 	"github.com/kaspanet/kaspad/util"
@@ -208,7 +209,7 @@ func (dag *BlockDAG) processBlockNoLock(block *util.Block, flags BehaviorFlags)
 		// The number K*2 was chosen since in peace times anticone is limited to K blocks,
 		// while some red block can make it a bit bigger, but much more than that indicates
 		// there might be some problem with the netsync process.
-		if flags&BFIsSync == BFIsSync && uint32(len(dag.orphans)) < dag.dagParams.K*2 {
+		if flags&BFIsSync == BFIsSync && dagconfig.KType(len(dag.orphans)) < dag.dagParams.K*2 {
 			log.Debugf("Adding orphan block %s. This is normal part of netsync process", blockHash)
 		} else {
 			log.Infof("Adding orphan block %s", blockHash)

dagconfig/params.go

@@ -82,11 +82,16 @@ const (
 	DefinedDeployments
 )
 
+// KType defines the size of GHOSTDAG consensus algorithm K parameter.
+type KType uint8
+
 // Params defines a Kaspa network by its parameters. These parameters may be
 // used by Kaspa applications to differentiate networks as well as addresses
 // and keys for one network from those intended for use on another network.
 type Params struct {
-	K uint32
+	// K defines the K parameter for GHOSTDAG consensus algorithm.
+	// See ghostdag.go for further details.
+	K KType
 
 	// Name defines a human-readable identifier for the network.
 	Name string