blockchain: update BestState.

This adds PrevHash, PoolSize, NextStakeDiff, WinningTickets, MissedTickets and FinalState fields to BestState and updates newBestState accordingly. This is in preparation of the removal of chainState.

blockchain/chain.go

@@ -86,27 +86,52 @@ type orphanBlock struct {
 // However, the returned snapshot must be treated as immutable since it is
 // shared by all callers.
 type BestState struct {
-	Hash         chainhash.Hash // The hash of the block.
-	Height       int64          // The height of the block.
-	Bits         uint32         // The difficulty bits of the block.
-	BlockSize    uint64         // The size of the block.
-	NumTxns      uint64         // The number of txns in the block.
-	TotalTxns    uint64         // The total number of txns in the chain.
-	MedianTime   time.Time      // Median time as per CalcPastMedianTime.
-	TotalSubsidy int64          // The total subsidy for the chain.
+	Hash           chainhash.Hash   // The hash of the block.
+	PrevHash       chainhash.Hash   // The previous block hash.
+	Height         int64            // The height of the block.
+	Bits           uint32           // The difficulty bits of the block.
+	PoolSize       uint32           // The ticket pool size.
+	NextStakeDiff  int64            // The next stake difficulty.
+	BlockSize      uint64           // The size of the block.
+	NumTxns        uint64           // The number of txns in the block.
+	TotalTxns      uint64           // The total number of txns in the chain.
+	MedianTime     time.Time        // Median time as per CalcPastMedianTime.
+	TotalSubsidy   int64            // The total subsidy for the chain.
+	WinningTickets []chainhash.Hash // The eligigle tickets to vote on the next block.
+	MissedTickets  []chainhash.Hash // The missed tickets set to be revoked.
+	FinalState     [6]byte          // The calculated state of the lottery.
 }
 
 // newBestState returns a new best stats instance for the given parameters.
-func newBestState(node *blockNode, blockSize, numTxns, totalTxns uint64, medianTime time.Time, totalSubsidy int64) *BestState {
+func newBestState(node *blockNode, blockSize, numTxns, totalTxns uint64, medianTime time.Time, totalSubsidy int64, nextStakeDiff int64) *BestState {
+	prevHash := *zeroHash
+	if node.parent != nil {
+		prevHash = node.parent.hash
+	}
+
+	winners := make([]chainhash.Hash, 0)
+	if node.stakeNode != nil {
+		winners = node.stakeNode.Winners()
+	}
+
+	missed := make([]chainhash.Hash, 0)
+	if node.parent != nil {
+		missed = node.stakeNode.MissedTickets()
+	}
 	return &BestState{
-		Hash:         node.hash,
-		Height:       node.height,
-		Bits:         node.bits,
-		BlockSize:    blockSize,
-		NumTxns:      numTxns,
-		TotalTxns:    totalTxns,
-		MedianTime:   medianTime,
-		TotalSubsidy: totalSubsidy,
+		Hash:           node.hash,
+		PrevHash:       prevHash,
+		Height:         node.height,
+		Bits:           node.bits,
+		PoolSize:       node.poolSize,
+		NextStakeDiff:  nextStakeDiff,
+		BlockSize:      blockSize,
+		NumTxns:        numTxns,
+		TotalTxns:      totalTxns,
+		MedianTime:     medianTime,
+		TotalSubsidy:   totalSubsidy,
+		WinningTickets: winners,
+		MissedTickets:  missed,
 	}
 }
 
@@ -761,9 +786,11 @@ func (b *BlockChain) connectBlock(node *blockNode, block, parent *dcrutil.Block,
 	// Calculate the exact subsidy produced by adding the block.
 	subsidy := CalculateAddedSubsidy(block, parent)
 
-	blockSize := uint64(block.MsgBlock().Header.Size)
-	state := newBestState(node, blockSize, numTxns, curTotalTxns+numTxns,
-		node.CalcPastMedianTime(), curTotalSubsidy+subsidy)
+	// Calcultate the next stake difficulty.
+	nextStakeDiff, err := b.calcNextRequiredStakeDifficulty(node)
+	if err != nil {
+		return err
+	}
 
 	// Get the stake node for this node, filling in any data that
 	// may have yet to have been filled in.  In all cases this
@@ -774,6 +801,10 @@ func (b *BlockChain) connectBlock(node *blockNode, block, parent *dcrutil.Block,
 		return err
 	}
 
+	blockSize := uint64(block.MsgBlock().Header.Size)
+	state := newBestState(node, blockSize, numTxns, curTotalTxns+numTxns,
+		node.CalcPastMedianTime(), curTotalSubsidy+subsidy, nextStakeDiff)
+
 	// Atomically insert info into the database.
 	err = b.db.Update(func(dbTx database.Tx) error {
 		// Update best block state.
@@ -934,10 +965,6 @@ func (b *BlockChain) disconnectBlock(node *blockNode, block, parent *dcrutil.Blo
 	subsidy := CalculateAddedSubsidy(block, parent)
 	newTotalSubsidy := curTotalSubsidy - subsidy
 
-	prevNode := node.parent
-	state := newBestState(prevNode, parentBlockSize, numTxns, newTotalTxns,
-		prevNode.CalcPastMedianTime(), newTotalSubsidy)
-
 	// Prepare the information required to update the stake database
 	// contents.
 	childStakeNode, err := b.fetchStakeNode(node)
@@ -949,6 +976,10 @@ func (b *BlockChain) disconnectBlock(node *blockNode, block, parent *dcrutil.Blo
 		return err
 	}
 
+	prevNode := node.parent
+	state := newBestState(prevNode, parentBlockSize, numTxns, newTotalTxns,
+		prevNode.CalcPastMedianTime(), newTotalSubsidy, node.sbits)
+
 	err = b.db.Update(func(dbTx database.Tx) error {
 		// Update best block state.
 		err := dbPutBestState(dbTx, state, node.workSum)

blockchain/chainio.go

@@ -1463,8 +1463,9 @@ func (b *BlockChain) createChainState() error {
 	// genesis block, use its timestamp for the median time.
 	numTxns := uint64(len(genesisBlock.MsgBlock().Transactions))
 	blockSize := uint64(genesisBlock.MsgBlock().SerializeSize())
+
 	stateSnapshot := newBestState(node, blockSize, numTxns, numTxns,
-		time.Unix(node.timestamp, 0), 0)
+		time.Unix(node.timestamp, 0), 0, b.chainParams.MinimumStakeDiff)
 
 	// Create the initial the database chain state including creating the
 	// necessary index buckets and inserting the genesis block.
@@ -1770,9 +1771,16 @@ func (b *BlockChain) initChainState(interrupt <-chan struct{}) error {
 		block := utilBlock.MsgBlock()
 		blockSize := uint64(block.SerializeSize())
 		numTxns := uint64(len(block.Transactions))
+
+		// Calculate the next stake difficulty.
+		nextStakeDiff, err := b.calcNextRequiredStakeDifficulty(tip)
+		if err != nil {
+			return err
+		}
+
 		b.stateSnapshot = newBestState(tip, blockSize, numTxns,
 			state.totalTxns, tip.CalcPastMedianTime(),
-			state.totalSubsidy)
+			state.totalSubsidy, nextStakeDiff)
 
 		return nil
 	})