blockchain: Simplify blocknode construction.

blockchain/accept.go

@@ -126,8 +126,6 @@ func (b *BlockChain) maybeAcceptBlock(block *dcrutil.Block, flags BehaviorFlags)
 		return false, ruleError(ErrMissingParent, str)
 	}
 
-	blockHeight := block.Height()
-
 	// The block must pass all of the validation rules which depend on the
 	// position of the block within the block chain.
 	err = b.checkBlockContext(block, prevNode, flags)
@@ -160,11 +158,8 @@ func (b *BlockChain) maybeAcceptBlock(block *dcrutil.Block, flags BehaviorFlags)
 	// Create a new block node for the block and add it to the in-memory
 	// block chain (could be either a side chain or the main chain).
 	blockHeader := &block.MsgBlock().Header
-	newNode := newBlockNode(blockHeader,
-		stake.FindSpentTicketsInBlock(block.MsgBlock()))
-	newNode.parent = prevNode
-	newNode.height = blockHeight
-	newNode.workSum.Add(prevNode.workSum, newNode.workSum)
+	newNode := newBlockNode(blockHeader, prevNode)
+	newNode.populateTicketInfo(stake.FindSpentTicketsInBlock(block.MsgBlock()))
 
 	// Fetching a stake node could enable a new DoS vector, so restrict
 	// this only to blocks that are recent in history.

blockchain/blockindex.go

@@ -91,11 +91,10 @@ type blockNode struct {
 	votes []stake.VoteVersionTuple
 }
 
-// newBlockNode returns a new block node for the given block header.  It is
-// completely disconnected from the chain and the workSum value is just the work
-// for the passed block.  The work sum is updated accordingly when the node is
-// inserted into a chain.
-func newBlockNode(blockHeader *wire.BlockHeader, spentTickets *stake.SpentTicketsInBlock) *blockNode {
+// newBlockNode returns a new block node for the given block header and parent
+// node.  The workSum is calculated based on the parent, or, in the case no
+// parent is provided, it will just be the work for the passed block.
+func newBlockNode(blockHeader *wire.BlockHeader, parent *blockNode) *blockNode {
 	// Serialize the block header for use in calculating the initialization
 	// vector for the ticket lottery.  The only way this can fail is if the
 	// process is out of memory in which case it would panic anyways, so
@@ -106,42 +105,35 @@ func newBlockNode(blockHeader *wire.BlockHeader, spentTickets *stake.SpentTicket
 		panic(err)
 	}
 
-	var ticketsVoted, ticketsRevoked []chainhash.Hash
-	var votes []stake.VoteVersionTuple
-	if spentTickets != nil {
-		ticketsVoted = spentTickets.VotedTickets
-		ticketsRevoked = spentTickets.RevokedTickets
-		votes = spentTickets.Votes
-	}
-
 	// Make a copy of the hash so the node doesn't keep a reference to part
 	// of the full block/block header preventing it from being garbage
 	// collected.
 	node := blockNode{
-		hash:           blockHeader.BlockHash(),
-		parentHash:     blockHeader.PrevBlock,
-		workSum:        CalcWork(blockHeader.Bits),
-		height:         int64(blockHeader.Height),
-		blockVersion:   blockHeader.Version,
-		voteBits:       blockHeader.VoteBits,
-		finalState:     blockHeader.FinalState,
-		voters:         blockHeader.Voters,
-		freshStake:     blockHeader.FreshStake,
-		poolSize:       blockHeader.PoolSize,
-		bits:           blockHeader.Bits,
-		sbits:          blockHeader.SBits,
-		timestamp:      blockHeader.Timestamp.Unix(),
-		merkleRoot:     blockHeader.MerkleRoot,
-		stakeRoot:      blockHeader.StakeRoot,
-		revocations:    blockHeader.Revocations,
-		blockSize:      blockHeader.Size,
-		nonce:          blockHeader.Nonce,
-		extraData:      blockHeader.ExtraData,
-		stakeVersion:   blockHeader.StakeVersion,
-		lotteryIV:      stake.CalcHash256PRNGIV(hB),
-		ticketsVoted:   ticketsVoted,
-		ticketsRevoked: ticketsRevoked,
-		votes:          votes,
+		hash:         blockHeader.BlockHash(),
+		parentHash:   blockHeader.PrevBlock,
+		workSum:      CalcWork(blockHeader.Bits),
+		height:       int64(blockHeader.Height),
+		blockVersion: blockHeader.Version,
+		voteBits:     blockHeader.VoteBits,
+		finalState:   blockHeader.FinalState,
+		voters:       blockHeader.Voters,
+		freshStake:   blockHeader.FreshStake,
+		poolSize:     blockHeader.PoolSize,
+		bits:         blockHeader.Bits,
+		sbits:        blockHeader.SBits,
+		timestamp:    blockHeader.Timestamp.Unix(),
+		merkleRoot:   blockHeader.MerkleRoot,
+		stakeRoot:    blockHeader.StakeRoot,
+		revocations:  blockHeader.Revocations,
+		blockSize:    blockHeader.Size,
+		nonce:        blockHeader.Nonce,
+		extraData:    blockHeader.ExtraData,
+		stakeVersion: blockHeader.StakeVersion,
+		lotteryIV:    stake.CalcHash256PRNGIV(hB),
+	}
+	if parent != nil {
+		node.parent = parent
+		node.workSum = node.workSum.Add(parent.workSum, node.workSum)
 	}
 
 	return &node
@@ -174,6 +166,17 @@ func (node *blockNode) Header() wire.BlockHeader {
 	}
 }
 
+// populateTicketInfo sets prunable ticket information in the provided block
+// node.
+//
+// This function is NOT safe for concurrent access.  It must only be called when
+// initially creating a node.
+func (node *blockNode) populateTicketInfo(spentTickets *stake.SpentTicketsInBlock) {
+	node.ticketsVoted = spentTickets.VotedTickets
+	node.ticketsRevoked = spentTickets.RevokedTickets
+	node.votes = spentTickets.Votes
+}
+
 // removeChildNode deletes node from the provided slice of child block
 // nodes.  It ensures the final pointer reference is set to nil to prevent
 // potential memory leaks.  The original slice is returned unmodified if node
@@ -253,7 +256,8 @@ func (bi *blockIndex) loadBlockNode(dbTx database.Tx, hash *chainhash.Hash) (*bl
 
 	// Create the new block node for the block.
 	blockHeader := block.MsgBlock().Header
-	node := newBlockNode(&blockHeader, stake.FindSpentTicketsInBlock(block.MsgBlock()))
+	node := newBlockNode(&blockHeader, nil)
+	node.populateTicketInfo(stake.FindSpentTicketsInBlock(block.MsgBlock()))
 	node.inMainChain = true
 
 	// Add the node to the chain.

blockchain/blockindex_test.go

@@ -54,9 +54,8 @@ func TestBlockNodeHeader(t *testing.T) {
 		ExtraData:    [32]byte{0xbb},
 		StakeVersion: 5,
 	}
-	node := newBlockNode(&testHeader, nil)
+	node := newBlockNode(&testHeader, bc.bestNode)
 	bc.index.AddNode(node)
-	node.parent = bc.bestNode
 
 	// Ensure reconstructing the header for the node produces the same header
 	// used to create the node.

blockchain/chainio.go

@@ -1476,7 +1476,8 @@ func (b *BlockChain) initChainState(interrupt <-chan struct{}) error {
 		// Create a new node and set it as the best node.  The preceding
 		// nodes will be loaded on demand as needed.
 		header := &block.Header
-		node := newBlockNode(header, stake.FindSpentTicketsInBlock(&block))
+		node := newBlockNode(header, nil)
+		node.populateTicketInfo(stake.FindSpentTicketsInBlock(&block))
 		node.inMainChain = true
 		node.workSum = state.workSum
 

blockchain/difficulty.go

@@ -1087,8 +1087,7 @@ func (b *BlockChain) estimateNextStakeDifficultyV1(curNode *blockNode, ticketsIn
 			// Connect the header.
 			emptyHeader.PrevBlock = topNode.hash
 
-			thisNode := newBlockNode(&emptyHeader, nil)
-			thisNode.parent = topNode
+			thisNode := newBlockNode(&emptyHeader, topNode)
 			topNode = thisNode
 		}
 	}

blockchain/difficulty_test.go

@@ -428,8 +428,7 @@ nextTest:
 					FreshStake: ticketInfo.newTickets,
 					PoolSize:   poolSize,
 				}
-				node := newBlockNode(header, nil)
-				node.parent = bc.bestNode
+				node := newBlockNode(header, bc.bestNode)
 
 				// Update the pool size for the next header.
 				// Notice how tickets that mature for this block
@@ -729,8 +728,7 @@ nextTest:
 					FreshStake: ticketInfo.newTickets,
 					PoolSize:   poolSize,
 				}
-				node := newBlockNode(header, nil)
-				node.parent = bc.bestNode
+				node := newBlockNode(header, bc.bestNode)
 
 				// Update the pool size for the next header.
 				// Notice how tickets that mature for this block

blockchain/internal_test.go

@@ -16,7 +16,6 @@ package blockchain
 import (
 	"sort"
 
-	"github.com/decred/dcrd/blockchain/stake"
 	"github.com/decred/dcrd/wire"
 )
 
@@ -40,6 +39,6 @@ func (b *BlockChain) TstCheckBlockHeaderContext(header *wire.BlockHeader, prevNo
 
 // TstNewBlockNode makes the internal newBlockNode function available to the
 // test package.
-func TstNewBlockNode(blockHeader *wire.BlockHeader, spentTickets *stake.SpentTicketsInBlock) *blockNode {
-	return newBlockNode(blockHeader, spentTickets)
+func TstNewBlockNode(blockHeader *wire.BlockHeader, parent *blockNode) *blockNode {
+	return newBlockNode(blockHeader, parent)
 }

blockchain/stakeversion_test.go

@@ -53,10 +53,7 @@ func newFakeNode(parent *blockNode, blockVersion int32, stakeVersion uint32, bit
 		Timestamp:    timestamp,
 		StakeVersion: stakeVersion,
 	}
-	node := newBlockNode(header, nil)
-	node.parent = parent
-	node.workSum.Add(parent.workSum, node.workSum)
-	return node
+	return newBlockNode(header, parent)
 }
 
 // appendFakeVotes appends the passed number of votes to the node with the

blockchain/validate.go

@@ -2601,10 +2601,8 @@ func (b *BlockChain) CheckConnectBlock(block *dcrutil.Block, flags BehaviorFlags
 		return err
 	}
 
-	newNode := newBlockNode(&block.MsgBlock().Header,
-		stake.FindSpentTicketsInBlock(block.MsgBlock()))
-	newNode.parent = prevNode
-	newNode.workSum.Add(prevNode.workSum, newNode.workSum)
+	newNode := newBlockNode(&block.MsgBlock().Header, prevNode)
+	newNode.populateTicketInfo(stake.FindSpentTicketsInBlock(block.MsgBlock()))
 
 	// If we are extending the main (best) chain with a new block, just use
 	// the ticket database we already have.

blockchain/validate_test.go

@@ -2110,7 +2110,7 @@ func TestCheckWorklessBlockSanity(t *testing.T) {
 }
 
 // TestCheckBlockHeaderContext tests that genesis block passes context headers
-// because it's previousNode is nil.
+// because its parent is nil.
 func TestCheckBlockHeaderContext(t *testing.T) {
 	// Create a new database for the blocks.
 	params := &chaincfg.SimNetParams
@@ -2145,8 +2145,7 @@ func TestCheckBlockHeaderContext(t *testing.T) {
 	// Test failing checkBlockHeaderContext when calcNextRequiredDifficulty
 	// fails.
 	block := dcrutil.NewBlock(&badBlock)
-	newNode := blockchain.TstNewBlockNode(&block.MsgBlock().Header,
-		&stake.SpentTicketsInBlock{})
+	newNode := blockchain.TstNewBlockNode(&block.MsgBlock().Header, nil)
 	err = chain.TstCheckBlockHeaderContext(&block.MsgBlock().Header, newNode, blockchain.BFNone)
 	if err == nil {
 		t.Fatalf("Should fail due to bad diff in newNode\n")