[DEV-169] add to BlockDAG TipHashes() and HighestTipHash() and remove Tiphashes() and SelectedTipHash from VirtualBlock (#82)

* [DEV-169] add to BlockDAG TipHashes() and HighestTipHash() and remove Tiphashes() and SelectedTipHash from VirtualBlock

* [DEV-169] move highest node logic to separate method of blockset

blockdag/blockset.go

@@ -35,6 +35,16 @@ func (bs blockSet) maxHeight() int32 {
 	return maxHeight
 }
 
+func (bs blockSet) highest() *blockNode {
+	var highest *blockNode
+	for _, node := range bs {
+		if highest.height < node.height || daghash.Less(&highest.hash, &node.hash) {
+			highest = node
+		}
+	}
+	return highest
+}
+
 // add adds a block to this BlockSet
 func (bs blockSet) add(block *blockNode) {
 	bs[block.hash] = block

blockdag/dag.go

@@ -516,7 +516,7 @@ func (dag *BlockDAG) connectBlock(node *blockNode, block *util.Block) error {
 	// Atomically insert info into the database.
 	err = dag.db.Update(func(dbTx database.Tx) error {
 		// Update best block state.
-		err := dbPutDAGTipHashes(dbTx, dag.virtual.TipHashes())
+		err := dbPutDAGTipHashes(dbTx, dag.TipHashes())
 		if err != nil {
 			return err
 		}
@@ -930,6 +930,17 @@ func (dag *BlockDAG) Height() int32 {
 	return dag.virtual.tips().maxHeight()
 }
 
+// TipHashes returns the hashes of the DAG's tips
+func (dag *BlockDAG) TipHashes() []daghash.Hash {
+	return dag.virtual.tips().hashes()
+}
+
+// HighestTipHash returns the hash of the highest tip.
+// This function is a placeholder for places that aren't DAG-compatible, and it's needed to be removed in the future
+func (dag *BlockDAG) HighestTipHash() daghash.Hash {
+	return dag.virtual.tips().highest().hash
+}
+
 // HeaderByHash returns the block header identified by the given hash or an
 // error if it doesn't exist.
 func (dag *BlockDAG) HeaderByHash(hash *daghash.Hash) (wire.BlockHeader, error) {

blockdag/dagio.go

@@ -811,7 +811,7 @@ func (dag *BlockDAG) createDAGState() error {
 		}
 
 		// Store the current DAG tip hashes into the database.
-		err = dbPutDAGTipHashes(dbTx, dag.virtual.TipHashes())
+		err = dbPutDAGTipHashes(dbTx, dag.TipHashes())
 		if err != nil {
 			return err
 		}

blockdag/fullblocks_test.go

@@ -272,14 +272,13 @@ func TestFullBlocks(t *testing.T) {
 			item.Name, block.Hash(), blockHeight)
 
 		// Ensure hash and height match.
-		virtualBlock := dag.VirtualBlock()
+		if dag.HighestTipHash() != item.Block.BlockHash() ||
-		if virtualBlock.SelectedTipHash() != item.Block.BlockHash() ||
+			dag.Height() != blockHeight { //TODO: (Ori) the use of dag.Height() and virtualBlock.HighestTipHash() is wrong, and was done only for compilation
-			dag.Height() != blockHeight { //TODO: (Ori) the use of dag.Height() and virtualBlock.SelectedTipHash() is wrong, and was done only for compilation
 
 			t.Fatalf("block %q (hash %s, height %d) should be "+
 				"the current tip -- got (hash %s, height %d)",
-				item.Name, block.Hash(), blockHeight, virtualBlock.SelectedTipHash(),
+				item.Name, block.Hash(), blockHeight, dag.HighestTipHash(),
-				dag.Height()) //TODO: (Ori) the use of dag.Height() and virtualBlock.SelectedTipHash() is wrong, and was done only for compilation
+				dag.Height()) //TODO: (Ori) the use of dag.Height() and virtualBlock.HighestTipHash() is wrong, and was done only for compilation
 		}
 	}
 

blockdag/virtualblock.go

@@ -7,7 +7,6 @@ package blockdag
 import (
 	"sync"
 
-	"github.com/daglabs/btcd/dagconfig/daghash"
 	"github.com/daglabs/btcd/wire"
 )
 
@@ -101,16 +100,6 @@ func (v *VirtualBlock) SelectedTip() *blockNode {
 	return v.selectedParent
 }
 
-// TipHashes returns the hashes of the tips of the virtual block.
-func (v *VirtualBlock) TipHashes() []daghash.Hash {
-	return v.tips().hashes()
-}
-
-// SelectedTipHash returns the hash of the selected tip of the virtual block.
-func (v *VirtualBlock) SelectedTipHash() daghash.Hash {
-	return v.SelectedTip().hash
-}
-
 // GetUTXOEntry returns the requested unspent transaction output. The returned
 // instance must be treated as immutable since it is shared by all callers.
 //

cmd/findcheckpoint/findcheckpoint.go

@@ -38,9 +38,9 @@ func loadBlockDB() (database.DB, error) {
 // returns a slice of found candidates, if any.  It also stops searching for
 // candidates at the last checkpoint that is already hard coded since there
 // is no point in finding candidates before already existing checkpoints.
-func findCandidates(dag *blockdag.BlockDAG, selectedTipHash *daghash.Hash) ([]*dagconfig.Checkpoint, error) {
+func findCandidates(dag *blockdag.BlockDAG, highestTipHash *daghash.Hash) ([]*dagconfig.Checkpoint, error) {
 	// Start with the selected tip.
-	block, err := dag.BlockByHash(selectedTipHash)
+	block, err := dag.BlockByHash(highestTipHash)
 	if err != nil {
 		return nil, err
 	}
@@ -162,12 +162,11 @@ func main() {
 
 	// Get the latest block hash and height from the database and report
 	// status.
-	virtualBlock := dag.VirtualBlock()
 	fmt.Printf("Block database loaded with block height %d\n", dag.Height())
 
 	// Find checkpoint candidates.
-	selectedTipHash := virtualBlock.SelectedTipHash()
+	highestTipHash := dag.HighestTipHash()
-	candidates, err := findCandidates(dag, &selectedTipHash)
+	candidates, err := findCandidates(dag, &highestTipHash)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, "Unable to identify candidates:", err)
 		return

mining/cpuminer/cpuminer.go

@@ -162,7 +162,7 @@ func (m *CPUMiner) submitBlock(block *util.Block) bool {
 	// a new block, but the check only happens periodically, so it is
 	// possible a block was found and submitted in between.
 	msgBlock := block.MsgBlock()
-	if !daghash.AreEqual(msgBlock.Header.PrevBlocks, m.g.VirtualBlock().TipHashes()) {
+	if !daghash.AreEqual(msgBlock.Header.PrevBlocks, m.g.TipHashes()) {
 		log.Debugf("Block submitted via CPU miner with previous "+
 			"blocks %s is stale", msgBlock.Header.PrevBlocks)
 		return false
@@ -247,8 +247,7 @@ func (m *CPUMiner) solveBlock(msgBlock *wire.MsgBlock, blockHeight int32,
 				hashesCompleted = 0
 
 				// The current block is stale if the DAG has changed.
-				virtualBlock := m.g.VirtualBlock()
+				if !daghash.AreEqual(header.PrevBlocks, m.g.TipHashes()) {
-				if !daghash.AreEqual(header.PrevBlocks, virtualBlock.TipHashes()) {
 					return false
 				}
 

mining/mining.go

@@ -717,8 +717,8 @@ mempoolLoop:
 	var msgBlock wire.MsgBlock
 	msgBlock.Header = wire.BlockHeader{
 		Version:       nextBlockVersion,
-		NumPrevBlocks: byte(len(virtualBlock.TipHashes())),
+		NumPrevBlocks: byte(len(g.dag.TipHashes())),
-		PrevBlocks:    virtualBlock.TipHashes(),
+		PrevBlocks:    g.dag.TipHashes(),
 		MerkleRoot:    *merkles[len(merkles)-1],
 		Timestamp:     ts,
 		Bits:          reqDifficulty,
@@ -820,6 +820,11 @@ func (g *BlkTmplGenerator) DAGHeight() int32 {
 	return g.dag.Height()
 }
 
+// TipHashes returns the hashes of the DAG's tips
+func (g *BlkTmplGenerator) TipHashes() []daghash.Hash {
+	return g.dag.TipHashes()
+}
+
 // TxSource returns the associated transaction source.
 //
 // This function is safe for concurrent access.

netsync/manager.go

@@ -392,9 +392,8 @@ func (sm *SyncManager) handleDonePeerMsg(peer *peerpkg.Peer) {
 	if sm.syncPeer == peer {
 		sm.syncPeer = nil
 		if sm.headersFirstMode {
-			virtualBlock := sm.dag.VirtualBlock()
+			highestTipHash := sm.dag.HighestTipHash()
-			selectedTipHash := virtualBlock.SelectedTipHash()
+			sm.resetHeaderState(&highestTipHash, sm.dag.Height()) //TODO: (Ori) This is probably wrong. Done only for compilation
-			sm.resetHeaderState(&selectedTipHash, sm.dag.Height()) //TODO: (Ori) This is probably wrong. Done only for compilation
 		}
 		sm.startSync()
 	}
@@ -616,10 +615,9 @@ func (sm *SyncManager) handleBlockMsg(bmsg *blockMsg) {
 
 		// Update this peer's latest block height, for future
 		// potential sync node candidacy.
-		virtualBlock := sm.dag.VirtualBlock()
+		highestTipHash := sm.dag.HighestTipHash()
-		selectedTipHash := virtualBlock.SelectedTipHash()
 		heightUpdate = sm.dag.Height() //TODO: (Ori) This is probably wrong. Done only for compilation
-		blkHashUpdate = &selectedTipHash
+		blkHashUpdate = &highestTipHash
 
 		// Clear the rejected transactions.
 		sm.rejectedTxns = make(map[daghash.Hash]struct{})
@@ -1389,13 +1387,12 @@ func New(config *Config) (*SyncManager, error) {
 		feeEstimator:    config.FeeEstimator,
 	}
 
-	virtualBlock := sm.dag.VirtualBlock()
+	highestTipHash := sm.dag.HighestTipHash()
-	selectedTipHash := virtualBlock.SelectedTipHash()
 	if !config.DisableCheckpoints {
 		// Initialize the next checkpoint based on the current height.
 		sm.nextCheckpoint = sm.findNextHeaderCheckpoint(sm.dag.Height()) //TODO: (Ori) This is probably wrong. Done only for compilation
 		if sm.nextCheckpoint != nil {
-			sm.resetHeaderState(&selectedTipHash, sm.dag.Height()) //TODO: (Ori) This is probably wrong. Done only for compilation)
+			sm.resetHeaderState(&highestTipHash, sm.dag.Height()) //TODO: (Ori) This is probably wrong. Done only for compilation)
 		}
 	} else {
 		log.Info("Checkpoints are disabled")

server/p2p/p2p.go

@@ -290,9 +290,8 @@ func newServerPeer(s *Server, isPersistent bool) *Peer {
 // newestBlock returns the current best block hash and height using the format
 // required by the configuration for the peer package.
 func (sp *Peer) newestBlock() (*daghash.Hash, int32, error) {
-	virtualBlock := sp.server.DAG.VirtualBlock()
+	highestTipHash := sp.server.DAG.HighestTipHash()
-	selectedTipHash := virtualBlock.SelectedTipHash()
+	return &highestTipHash, sp.server.DAG.Height(), nil //TODO: (Ori) This is probably wrong. Done only for compilation
-	return &selectedTipHash, sp.server.DAG.Height(), nil //TODO: (Ori) This is probably wrong. Done only for compilation
 }
 
 // addKnownAddresses adds the given addresses to the set of known addresses to
@@ -1308,9 +1307,9 @@ func (s *Server) pushBlockMsg(sp *Peer, hash *daghash.Hash, doneChan chan<- stru
 	// to trigger it to issue another getblocks message for the next
 	// batch of inventory.
 	if sendInv {
-		selectedTipHash := sp.server.DAG.VirtualBlock().SelectedTipHash()
+		highestTipHash := sp.server.DAG.HighestTipHash()
 		invMsg := wire.NewMsgInvSizeHint(1)
-		iv := wire.NewInvVect(wire.InvTypeBlock, &selectedTipHash)
+		iv := wire.NewInvVect(wire.InvTypeBlock, &highestTipHash)
 		invMsg.AddInvVect(iv)
 		sp.QueueMessage(invMsg, doneChan)
 		sp.continueHash = nil

server/rpc/rpcserver.go

@@ -1008,9 +1008,8 @@ func handleGetBestBlock(s *Server, cmd interface{}, closeChan <-chan struct{}) (
 	// All other "get block" commands give either the height, the
 	// hash, or both but require the block SHA.  This gets both for
 	// the best block.
-	virtualBlock := s.cfg.DAG.VirtualBlock()
 	result := &btcjson.GetBestBlockResult{
-		Hash:   virtualBlock.SelectedTipHash().String(),
+		Hash:   s.cfg.DAG.HighestTipHash().String(),
 		Height: s.cfg.DAG.Height(), //TODO: (Ori) This is probably wrong. Done only for compilation
 	}
 	return result, nil
@@ -1018,8 +1017,7 @@ func handleGetBestBlock(s *Server, cmd interface{}, closeChan <-chan struct{}) (
 
 // handleGetBestBlockHash implements the getbestblockhash command.
 func handleGetBestBlockHash(s *Server, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
-	virtualBlock := s.cfg.DAG.VirtualBlock()
+	return s.cfg.DAG.HighestTipHash().String(), nil
-	return virtualBlock.SelectedTipHash().String(), nil
 }
 
 // getDifficultyRatio returns the proof-of-work difficulty as a multiple of the
@@ -1173,7 +1171,7 @@ func handleGetBlockDAGInfo(s *Server, cmd interface{}, closeChan <-chan struct{}
 		DAG:           params.Name,
 		Blocks:        dag.Height(), //TODO: (Ori) This is wrong. Done only for compilation
 		Headers:       dag.Height(), //TODO: (Ori) This is wrong. Done only for compilation
-		TipHashes:     daghash.Strings(virtualBlock.TipHashes()),
+		TipHashes:     daghash.Strings(dag.TipHashes()),
 		Difficulty:    getDifficultyRatio(virtualBlock.SelectedTip().Header().Bits, params),
 		MedianTime:    virtualBlock.SelectedTip().CalcPastMedianTime().Unix(),
 		Pruned:        false,
@@ -1490,7 +1488,7 @@ func (state *gbtWorkState) updateBlockTemplate(s *Server, useCoinbaseValue bool)
 	var msgBlock *wire.MsgBlock
 	var targetDifficulty string
 	virtualBlock := s.cfg.DAG.VirtualBlock()
-	tipHashes := virtualBlock.TipHashes()
+	tipHashes := s.cfg.DAG.TipHashes()
 	template := state.template
 	if template == nil || state.tipHashes == nil ||
 		!daghash.AreEqual(state.tipHashes, tipHashes) ||
@@ -2050,7 +2048,7 @@ func handleGetBlockTemplateProposal(s *Server, request *btcjson.TemplateRequest)
 	block := util.NewBlock(&msgBlock)
 
 	// Ensure the block is building from the expected previous blocks.
-	expectedPrevHashes := s.cfg.DAG.VirtualBlock().TipHashes()
+	expectedPrevHashes := s.cfg.DAG.TipHashes()
 	prevHashes := block.MsgBlock().Header.PrevBlocks
 	if !daghash.AreEqual(expectedPrevHashes, prevHashes) {
 		return "bad-prevblk", nil
@@ -2283,8 +2281,8 @@ func handleGetMiningInfo(s *Server, cmd interface{}, closeChan <-chan struct{})
 	}
 
 	virtualBlock := s.cfg.DAG.VirtualBlock()
-	selectedTipHash := virtualBlock.SelectedTipHash()
+	highestTipHash := s.cfg.DAG.HighestTipHash()
-	selectedBlock, err := s.cfg.DAG.BlockByHash(&selectedTipHash)
+	selectedBlock, err := s.cfg.DAG.BlockByHash(&highestTipHash)
 	if err != nil {
 		return nil, &btcjson.RPCError{
 			Code:    btcjson.ErrRPCInternal.Code,
@@ -2548,8 +2546,7 @@ func handleGetTxOut(s *Server, cmd interface{}, closeChan <-chan struct{}) (inte
 			return nil, internalRPCError(errStr, "")
 		}
 
-		virtualBlock := s.cfg.DAG.VirtualBlock()
+		bestBlockHash = s.cfg.DAG.HighestTipHash().String()
-		bestBlockHash = virtualBlock.SelectedTipHash().String()
 		confirmations = 0
 		value = txOut.Value
 		pkScript = txOut.PkScript
@@ -2570,8 +2567,7 @@ func handleGetTxOut(s *Server, cmd interface{}, closeChan <-chan struct{}) (inte
 			return nil, nil
 		}
 
-		virtualBlock := s.cfg.DAG.VirtualBlock()
+		bestBlockHash = s.cfg.DAG.HighestTipHash().String()
-		bestBlockHash = virtualBlock.SelectedTipHash().String()
 		confirmations = 1 + s.cfg.DAG.Height() - entry.BlockHeight() //TODO: (Ori) This is probably wrong. Done only for compilation
 		value = entry.Amount()
 		pkScript = entry.PkScript()
@@ -3322,7 +3318,6 @@ func handleValidateAddress(s *Server, cmd interface{}, closeChan <-chan struct{}
 }
 
 func verifyDAG(s *Server, level, depth int32) error {
-	virtualBlock := s.cfg.DAG.VirtualBlock()
 	finishHeight := s.cfg.DAG.Height() - depth //TODO: (Ori) This is probably wrong. Done only for compilation
 	if finishHeight < 0 {
 		finishHeight = 0
@@ -3330,7 +3325,7 @@ func verifyDAG(s *Server, level, depth int32) error {
 	log.Infof("Verifying chain for %d blocks at level %d",
 		s.cfg.DAG.Height()-finishHeight, level) //TODO: (Ori) This is probably wrong. Done only for compilation
 
-	currentHash := virtualBlock.SelectedTipHash()
+	currentHash := s.cfg.DAG.HighestTipHash()
 	for height := s.cfg.DAG.Height(); height > finishHeight; { //TODO: (Ori) This is probably wrong. Done only for compilation
 		// Level 0 just looks up the block.
 		block, err := s.cfg.DAG.BlockByHash(&currentHash)