Golang Block.MsgBlock方法代码示例

// dbIndexDisconnectBlock removes all of the index entries associated with the
// given block using the provided indexer and updates the tip of the indexer
// accordingly.  An error will be returned if the current tip for the indexer is
// not the passed block.
func dbIndexDisconnectBlock(dbTx database.Tx, indexer Indexer, block *btcutil.Block, view *blockchain.UtxoViewpoint) error {
	// Assert that the block being disconnected is the current tip of the
	// index.
	idxKey := indexer.Key()
	curTipHash, _, err := dbFetchIndexerTip(dbTx, idxKey)
	if err != nil {
		return err
	}
	if !curTipHash.IsEqual(block.Hash()) {
		return AssertError(fmt.Sprintf("dbIndexDisconnectBlock must "+
			"be called with the block at the current index tip "+
			"(%s, tip %s, block %s)", indexer.Name(),
			curTipHash, block.Hash()))
	}

	// Notify the indexer with the disconnected block so it can remove all
	// of the appropriate entries.
	if err := indexer.DisconnectBlock(dbTx, block, view); err != nil {
		return err
	}

	// Update the current index tip.
	prevHash := &block.MsgBlock().Header.PrevBlock
	return dbPutIndexerTip(dbTx, idxKey, prevHash, block.Height()-1)
}

// LogBlockHeight logs a new block height as an information message to show
// progress to the user. In order to prevent spam, it limits logging to one
// message every 10 seconds with duration and totals included.
func (b *blockProgressLogger) LogBlockHeight(block *btcutil.Block) {
	b.Lock()
	defer b.Unlock()

	b.receivedLogBlocks++
	b.receivedLogTx += int64(len(block.MsgBlock().Transactions))

	now := time.Now()
	duration := now.Sub(b.lastBlockLogTime)
	if duration < time.Second*10 {
		return
	}

	// Truncate the duration to 10s of milliseconds.
	durationMillis := int64(duration / time.Millisecond)
	tDuration := 10 * time.Millisecond * time.Duration(durationMillis/10)

	// Log information about new block height.
	blockStr := "blocks"
	if b.receivedLogBlocks == 1 {
		blockStr = "block"
	}
	txStr := "transactions"
	if b.receivedLogTx == 1 {
		txStr = "transaction"
	}
	b.subsystemLogger.Infof("%s %d %s in the last %s (%d %s, height %d, %s)",
		b.progressAction, b.receivedLogBlocks, blockStr, tDuration, b.receivedLogTx,
		txStr, block.Height(), block.MsgBlock().Header.Timestamp)

	b.receivedLogBlocks = 0
	b.receivedLogTx = 0
	b.lastBlockLogTime = now
}

// GetBlockWeight computes the value of the weight metric for a given block.
// Currently the weight metric is simply the sum of the block's serialized size
// without any witness data scaled proportionally by the WitnessScaleFactor,
// and the block's serialized size including any witness data.
func GetBlockWeight(blk *btcutil.Block) int64 {
	msgBlock := blk.MsgBlock()

	baseSize := msgBlock.SerializeSizeStripped()
	totalSize := msgBlock.SerializeSize()

	// (baseSize * 3) + totalSize
	return int64((baseSize * (WitnessScaleFactor - 1)) + totalSize)
}

// maybeAcceptBlock potentially accepts a block into the block chain and, if
// accepted, returns whether or not it is on the main chain.  It performs
// several validation checks which depend on its position within the block chain
// before adding it.  The block is expected to have already gone through
// ProcessBlock before calling this function with it.
//
// The flags modify the behavior of this function as follows:
//  - BFDryRun: The memory chain index will not be pruned and no accept
//    notification will be sent since the block is not being accepted.
//
// The flags are also passed to checkBlockContext and connectBestChain.  See
// their documentation for how the flags modify their behavior.
//
// This function MUST be called with the chain state lock held (for writes).
func (b *BlockChain) maybeAcceptBlock(block *btcutil.Block, flags BehaviorFlags) (bool, error) {
	dryRun := flags&BFDryRun == BFDryRun

	// Get a block node for the block previous to this one.  Will be nil
	// if this is the genesis block.
	prevNode, err := b.getPrevNodeFromBlock(block)
	if err != nil {
		log.Errorf("getPrevNodeFromBlock: %v", err)
		return false, err
	}

	// The height of this block is one more than the referenced previous
	// block.
	blockHeight := int32(0)
	if prevNode != nil {
		blockHeight = prevNode.height + 1
	}
	block.SetHeight(blockHeight)

	// 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)
	if err != nil {
		return false, err
	}

	// 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, block.Hash(), blockHeight)
	if prevNode != nil {
		newNode.parent = prevNode
		newNode.height = blockHeight
		newNode.workSum.Add(prevNode.workSum, newNode.workSum)
	}

	// Connect the passed block to the chain while respecting proper chain
	// selection according to the chain with the most proof of work.  This
	// also handles validation of the transaction scripts.
	isMainChain, err := b.connectBestChain(newNode, block, flags)
	if err != nil {
		return false, err
	}

	// Notify the caller that the new block was accepted into the block
	// chain.  The caller would typically want to react by relaying the
	// inventory to other peers.
	if !dryRun {
		b.chainLock.Unlock()
		b.sendNotification(NTBlockAccepted, block)
		b.chainLock.Lock()
	}

	return isMainChain, nil
}

// CheckConnectBlock performs several checks to confirm connecting the passed
// block to the main chain does not violate any rules.  An example of some of
// the checks performed are ensuring connecting the block would not cause any
// duplicate transaction hashes for old transactions that aren't already fully
// spent, double spends, exceeding the maximum allowed signature operations
// per block, invalid values in relation to the expected block subsidy, or fail
// transaction script validation.
//
// This function is safe for concurrent access.
func (b *BlockChain) CheckConnectBlock(block *btcutil.Block) error {
	b.chainLock.Lock()
	defer b.chainLock.Unlock()

	prevNode := b.bestNode
	newNode := newBlockNode(&block.MsgBlock().Header, block.Hash(),
		prevNode.height+1)
	newNode.parent = prevNode
	newNode.workSum.Add(prevNode.workSum, newNode.workSum)

	// Leave the spent txouts entry nil in the state since the information
	// is not needed and thus extra work can be avoided.
	view := NewUtxoViewpoint()
	view.SetBestHash(prevNode.hash)
	return b.checkConnectBlock(newNode, block, view, nil)
}

// submitBlock submits the passed block to network after ensuring it passes all
// of the consensus validation rules.
func (m *CPUMiner) submitBlock(block *btcutil.Block) bool {
	m.submitBlockLock.Lock()
	defer m.submitBlockLock.Unlock()

	// Ensure the block is not stale since a new block could have shown up
	// while the solution was being found.  Typically that condition is
	// detected and all work on the stale block is halted to start work on
	// 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 !msgBlock.Header.PrevBlock.IsEqual(m.g.BestSnapshot().Hash) {
		log.Debugf("Block submitted via CPU miner with previous "+
			"block %s is stale", msgBlock.Header.PrevBlock)
		return false
	}

	// Process this block using the same rules as blocks coming from other
	// nodes.  This will in turn relay it to the network like normal.
	isOrphan, err := m.cfg.ProcessBlock(block, blockchain.BFNone)
	if err != nil {
		// Anything other than a rule violation is an unexpected error,
		// so log that error as an internal error.
		if _, ok := err.(blockchain.RuleError); !ok {
			log.Errorf("Unexpected error while processing "+
				"block submitted via CPU miner: %v", err)
			return false
		}

		log.Debugf("Block submitted via CPU miner rejected: %v", err)
		return false
	}
	if isOrphan {
		log.Debugf("Block submitted via CPU miner is an orphan")
		return false
	}

	// The block was accepted.
	coinbaseTx := block.MsgBlock().Transactions[0].TxOut[0]
	log.Infof("Block submitted via CPU miner accepted (hash %s, "+
		"amount %v)", block.Hash(), btcutil.Amount(coinbaseTx.Value))
	return true
}

// dbIndexConnectBlock adds all of the index entries associated with the
// given block using the provided indexer and updates the tip of the indexer
// accordingly.  An error will be returned if the current tip for the indexer is
// not the previous block for the passed block.
func dbIndexConnectBlock(dbTx database.Tx, indexer Indexer, block *btcutil.Block, view *blockchain.UtxoViewpoint) error {
	// Assert that the block being connected properly connects to the
	// current tip of the index.
	idxKey := indexer.Key()
	curTipHash, _, err := dbFetchIndexerTip(dbTx, idxKey)
	if err != nil {
		return err
	}
	if !curTipHash.IsEqual(&block.MsgBlock().Header.PrevBlock) {
		return AssertError(fmt.Sprintf("dbIndexConnectBlock must be "+
			"called with a block that extends the current index "+
			"tip (%s, tip %s, block %s)", indexer.Name(),
			curTipHash, block.Hash()))
	}

	// Notify the indexer with the connected block so it can index it.
	if err := indexer.ConnectBlock(dbTx, block, view); err != nil {
		return err
	}

	// Update the current index tip.
	return dbPutIndexerTip(dbTx, idxKey, block.Hash(), block.Height())
}

// IsCheckpointCandidate returns whether or not the passed block is a good
// checkpoint candidate.
//
// The factors used to determine a good checkpoint are:
//  - The block must be in the main chain
//  - The block must be at least 'CheckpointConfirmations' blocks prior to the
//    current end of the main chain
//  - The timestamps for the blocks before and after the checkpoint must have
//    timestamps which are also before and after the checkpoint, respectively
//    (due to the median time allowance this is not always the case)
//  - The block must not contain any strange transaction such as those with
//    nonstandard scripts
//
// The intent is that candidates are reviewed by a developer to make the final
// decision and then manually added to the list of checkpoints for a network.
//
// This function is safe for concurrent access.
func (b *BlockChain) IsCheckpointCandidate(block *btcutil.Block) (bool, error) {
	b.chainLock.RLock()
	defer b.chainLock.RUnlock()

	// Checkpoints must be enabled.
	if b.noCheckpoints {
		return false, fmt.Errorf("checkpoints are disabled")
	}

	var isCandidate bool
	err := b.db.View(func(dbTx database.Tx) error {
		// A checkpoint must be in the main chain.
		blockHeight, err := dbFetchHeightByHash(dbTx, block.Hash())
		if err != nil {
			// Only return an error if it's not due to the block not
			// being in the main chain.
			if !isNotInMainChainErr(err) {
				return err
			}
			return nil
		}

		// Ensure the height of the passed block and the entry for the
		// block in the main chain match.  This should always be the
		// case unless the caller provided an invalid block.
		if blockHeight != block.Height() {
			return fmt.Errorf("passed block height of %d does not "+
				"match the main chain height of %d",
				block.Height(), blockHeight)
		}

		// A checkpoint must be at least CheckpointConfirmations blocks
		// before the end of the main chain.
		mainChainHeight := b.bestNode.height
		if blockHeight > (mainChainHeight - CheckpointConfirmations) {
			return nil
		}

		// Get the previous block header.
		prevHash := &block.MsgBlock().Header.PrevBlock
		prevHeader, err := dbFetchHeaderByHash(dbTx, prevHash)
		if err != nil {
			return err
		}

		// Get the next block header.
		nextHeader, err := dbFetchHeaderByHeight(dbTx, blockHeight+1)
		if err != nil {
			return err
		}

		// A checkpoint must have timestamps for the block and the
		// blocks on either side of it in order (due to the median time
		// allowance this is not always the case).
		prevTime := prevHeader.Timestamp
		curTime := block.MsgBlock().Header.Timestamp
		nextTime := nextHeader.Timestamp
		if prevTime.After(curTime) || nextTime.Before(curTime) {
			return nil
		}

		// A checkpoint must have transactions that only contain
		// standard scripts.
		for _, tx := range block.Transactions() {
			if isNonstandardTransaction(tx) {
				return nil
			}
		}

		// All of the checks passed, so the block is a candidate.
		isCandidate = true
		return nil
	})
	return isCandidate, err
}

// CreateBlock creates a new block building from the previous block with a
// specified blockversion and timestamp. If the timestamp passed is zero (not
// initialized), then the timestamp of the previous block will be used plus 1
// second is used. Passing nil for the previous block results in a block that
// builds off of the genesis block for the specified chain.
func CreateBlock(prevBlock *btcutil.Block, inclusionTxs []*btcutil.Tx,
	blockVersion int32, blockTime time.Time,
	miningAddr btcutil.Address, net *chaincfg.Params) (*btcutil.Block, error) {

	var (
		prevHash      *chainhash.Hash
		blockHeight   int32
		prevBlockTime time.Time
	)

	// If the previous block isn't specified, then we'll construct a block
	// that builds off of the genesis block for the chain.
	if prevBlock == nil {
		prevHash = net.GenesisHash
		blockHeight = 1
		prevBlockTime = net.GenesisBlock.Header.Timestamp.Add(time.Minute)
	} else {
		prevHash = prevBlock.Hash()
		blockHeight = prevBlock.Height() + 1
		prevBlockTime = prevBlock.MsgBlock().Header.Timestamp
	}

	// If a target block time was specified, then use that as the header's
	// timestamp. Otherwise, add one second to the previous block unless
	// it's the genesis block in which case use the current time.
	var ts time.Time
	switch {
	case !blockTime.IsZero():
		ts = blockTime
	default:
		ts = prevBlockTime.Add(time.Second)
	}

	extraNonce := uint64(0)
	coinbaseScript, err := standardCoinbaseScript(blockHeight, extraNonce)
	if err != nil {
		return nil, err
	}
	coinbaseTx, err := createCoinbaseTx(coinbaseScript, blockHeight,
		miningAddr, net)
	if err != nil {
		return nil, err
	}

	// Create a new block ready to be solved.
	blockTxns := []*btcutil.Tx{coinbaseTx}
	if inclusionTxs != nil {
		blockTxns = append(blockTxns, inclusionTxs...)
	}
	merkles := blockchain.BuildMerkleTreeStore(blockTxns, false)
	var block wire.MsgBlock
	block.Header = wire.BlockHeader{
		Version:    blockVersion,
		PrevBlock:  *prevHash,
		MerkleRoot: *merkles[len(merkles)-1],
		Timestamp:  ts,
		Bits:       net.PowLimitBits,
	}
	for _, tx := range blockTxns {
		if err := block.AddTransaction(tx.MsgTx()); err != nil {
			return nil, err
		}
	}

	found := solveBlock(&block.Header, net.PowLimit)
	if !found {
		return nil, errors.New("Unable to solve block")
	}

	utilBlock := btcutil.NewBlock(&block)
	utilBlock.SetHeight(blockHeight)
	return utilBlock, nil
}

// disconnectTransactions updates the view by removing all of the transactions
// created by the passed block, restoring all utxos the transactions spent by
// using the provided spent txo information, and setting the best hash for the
// view to the block before the passed block.
func (view *UtxoViewpoint) disconnectTransactions(block *btcutil.Block, stxos []spentTxOut) error {
	// Sanity check the correct number of stxos are provided.
	if len(stxos) != countSpentOutputs(block) {
		return AssertError("disconnectTransactions called with bad " +
			"spent transaction out information")
	}

	// Loop backwards through all transactions so everything is unspent in
	// reverse order.  This is necessary since transactions later in a block
	// can spend from previous ones.
	stxoIdx := len(stxos) - 1
	transactions := block.Transactions()
	for txIdx := len(transactions) - 1; txIdx > -1; txIdx-- {
		tx := transactions[txIdx]

		// Clear this transaction from the view if it already exists or
		// create a new empty entry for when it does not.  This is done
		// because the code relies on its existence in the view in order
		// to signal modifications have happened.
		isCoinbase := txIdx == 0
		entry := view.entries[*tx.Hash()]
		if entry == nil {
			entry = newUtxoEntry(tx.MsgTx().Version, isCoinbase,
				block.Height())
			view.entries[*tx.Hash()] = entry
		}
		entry.modified = true
		entry.sparseOutputs = make(map[uint32]*utxoOutput)

		// Loop backwards through all of the transaction inputs (except
		// for the coinbase which has no inputs) and unspend the
		// referenced txos.  This is necessary to match the order of the
		// spent txout entries.
		if isCoinbase {
			continue
		}
		for txInIdx := len(tx.MsgTx().TxIn) - 1; txInIdx > -1; txInIdx-- {
			// Ensure the spent txout index is decremented to stay
			// in sync with the transaction input.
			stxo := &stxos[stxoIdx]
			stxoIdx--

			// When there is not already an entry for the referenced
			// transaction in the view, it means it was fully spent,
			// so create a new utxo entry in order to resurrect it.
			txIn := tx.MsgTx().TxIn[txInIdx]
			originHash := &txIn.PreviousOutPoint.Hash
			originIndex := txIn.PreviousOutPoint.Index
			entry := view.entries[*originHash]
			if entry == nil {
				entry = newUtxoEntry(stxo.version,
					stxo.isCoinBase, stxo.height)
				view.entries[*originHash] = entry
			}

			// Mark the entry as modified since it is either new
			// or will be changed below.
			entry.modified = true

			// Restore the specific utxo using the stxo data from
			// the spend journal if it doesn't already exist in the
			// view.
			output, ok := entry.sparseOutputs[originIndex]
			if !ok {
				// Add the unspent transaction output.
				entry.sparseOutputs[originIndex] = &utxoOutput{
					spent:      false,
					compressed: stxo.compressed,
					amount:     stxo.amount,
					pkScript:   stxo.pkScript,
				}
				continue
			}

			// Mark the existing referenced transaction output as
			// unspent.
			output.spent = false
		}
	}

	// Update the best hash for view to the previous block since all of the
	// transactions for the current block have been disconnected.
	view.SetBestHash(&block.MsgBlock().Header.PrevBlock)
	return nil
}

// checkBlockContext peforms several validation checks on the block which depend
// on its position within the block chain.
//
// The flags modify the behavior of this function as follows:
//  - BFFastAdd: The transaction are not checked to see if they are finalized
//    and the somewhat expensive BIP0034 validation is not performed.
//
// The flags are also passed to checkBlockHeaderContext.  See its documentation
// for how the flags modify its behavior.
//
// This function MUST be called with the chain state lock held (for writes).
func (b *BlockChain) checkBlockContext(block *btcutil.Block, prevNode *blockNode, flags BehaviorFlags) error {
	// The genesis block is valid by definition.
	if prevNode == nil {
		return nil
	}

	// Perform all block header related validation checks.
	header := &block.MsgBlock().Header
	err := b.checkBlockHeaderContext(header, prevNode, flags)
	if err != nil {
		return err
	}

	// Query for the Version Bits state for the segwit soft-fork
	// deployment. If segwit is active, we'll switch over to enforcing all
	// the new rules.
	segwitState, err := b.deploymentState(prevNode, chaincfg.DeploymentSegwit)
	if err != nil {
		return err
	}

	// If segwit is active, then we'll need to fully validate the new
	// witness commitment for adherance to the rules.
	if segwitState == ThresholdActive {
		// Validate the witness commitment (if any) within the block.
		// This involves asserting that if the coinbase contains the
		// special commitment output, then this merkle root matches a
		// computed merkle root of all the wtxid's of the transactions
		// within the block. In addition, various other checks against
		// the coinbase's witness stack.
		if err := ValidateWitnessCommitment(block); err != nil {
			return err
		}
	}

	fastAdd := flags&BFFastAdd == BFFastAdd
	if !fastAdd {
		// Obtain the latest state of the deployed CSV soft-fork in
		// order to properly guard the new validation behavior based on
		// the current BIP 9 version bits state.
		csvState, err := b.deploymentState(prevNode, chaincfg.DeploymentCSV)
		if err != nil {
			return err
		}

		// Once the CSV soft-fork is fully active, we'll switch to
		// using the current median time past of the past block's
		// timestamps for all lock-time based checks.
		blockTime := header.Timestamp
		if csvState == ThresholdActive {
			medianTime, err := b.calcPastMedianTime(prevNode)
			if err != nil {
				return err
			}

			blockTime = medianTime
		}

		// The height of this block is one more than the referenced
		// previous block.
		blockHeight := prevNode.height + 1

		// Ensure all transactions in the block are finalized.
		for _, tx := range block.Transactions() {
			if !IsFinalizedTransaction(tx, blockHeight,
				blockTime) {

				str := fmt.Sprintf("block contains unfinalized "+
					"transaction %v", tx.Hash())
				return ruleError(ErrUnfinalizedTx, str)
			}
		}

		// Ensure coinbase starts with serialized block heights for
		// blocks whose version is the serializedHeightVersion or newer
		// once a majority of the network has upgraded.  This is part of
		// BIP0034.
		if ShouldHaveSerializedBlockHeight(header) &&
			blockHeight >= b.chainParams.BIP0034Height {

			coinbaseTx := block.Transactions()[0]
			err := checkSerializedHeight(coinbaseTx, blockHeight)
			if err != nil {
				return err
			}
		}
	}

	return nil
//.........这里部分代码省略.........

// checkBlockSanity performs some preliminary checks on a block to ensure it is
// sane before continuing with block processing.  These checks are context free.
//
// The flags do not modify the behavior of this function directly, however they
// are needed to pass along to checkBlockHeaderSanity.
func checkBlockSanity(block *btcutil.Block, powLimit *big.Int, timeSource MedianTimeSource, flags BehaviorFlags) error {
	msgBlock := block.MsgBlock()
	header := &msgBlock.Header
	err := checkBlockHeaderSanity(header, powLimit, timeSource, flags)
	if err != nil {
		return err
	}

	// A block must have at least one transaction.
	numTx := len(msgBlock.Transactions)
	if numTx == 0 {
		return ruleError(ErrNoTransactions, "block does not contain "+
			"any transactions")
	}

	// A block must not have more transactions than the max block payload.
	if numTx > wire.MaxBlockPayload {
		str := fmt.Sprintf("block contains too many transactions - "+
			"got %d, max %d", numTx, wire.MaxBlockPayload)
		return ruleError(ErrTooManyTransactions, str)
	}

	// A block must not exceed the maximum allowed block payload when
	// serialized.
	serializedSize := msgBlock.SerializeSizeStripped()
	if serializedSize > MaxBlockBaseSize {
		str := fmt.Sprintf("serialized block is too big - got %d, "+
			"max %d", serializedSize, MaxBlockBaseSize)
		return ruleError(ErrBlockTooBig, str)
	}

	// The first transaction in a block must be a coinbase.
	transactions := block.Transactions()
	if !IsCoinBase(transactions[0]) {
		return ruleError(ErrFirstTxNotCoinbase, "first transaction in "+
			"block is not a coinbase")
	}

	// A block must not have more than one coinbase.
	for i, tx := range transactions[1:] {
		if IsCoinBase(tx) {
			str := fmt.Sprintf("block contains second coinbase at "+
				"index %d", i+1)
			return ruleError(ErrMultipleCoinbases, str)
		}
	}

	// Do some preliminary checks on each transaction to ensure they are
	// sane before continuing.
	for _, tx := range transactions {
		err := CheckTransactionSanity(tx)
		if err != nil {
			return err
		}
	}

	// Build merkle tree and ensure the calculated merkle root matches the
	// entry in the block header.  This also has the effect of caching all
	// of the transaction hashes in the block to speed up future hash
	// checks.  Bitcoind builds the tree here and checks the merkle root
	// after the following checks, but there is no reason not to check the
	// merkle root matches here.
	merkles := BuildMerkleTreeStore(block.Transactions(), false)
	calculatedMerkleRoot := merkles[len(merkles)-1]
	if !header.MerkleRoot.IsEqual(calculatedMerkleRoot) {
		str := fmt.Sprintf("block merkle root is invalid - block "+
			"header indicates %v, but calculated value is %v",
			header.MerkleRoot, calculatedMerkleRoot)
		return ruleError(ErrBadMerkleRoot, str)
	}

	// Check for duplicate transactions.  This check will be fairly quick
	// since the transaction hashes are already cached due to building the
	// merkle tree above.
	existingTxHashes := make(map[chainhash.Hash]struct{})
	for _, tx := range transactions {
		hash := tx.Hash()
		if _, exists := existingTxHashes[*hash]; exists {
			str := fmt.Sprintf("block contains duplicate "+
				"transaction %v", hash)
			return ruleError(ErrDuplicateTx, str)
		}
		existingTxHashes[*hash] = struct{}{}
	}

	// The number of signature operations must be less than the maximum
	// allowed per block.
	totalSigOps := 0
	for _, tx := range transactions {
		// We could potentially overflow the accumulator so check for
		// overflow.
		lastSigOps := totalSigOps
		totalSigOps += (CountSigOps(tx) * WitnessScaleFactor)
		if totalSigOps < lastSigOps || totalSigOps > MaxBlockSigOpsCost {
			str := fmt.Sprintf("block contains too many signature "+
//.........这里部分代码省略.........

// CheckProofOfWork ensures the block header bits which indicate the target
// difficulty is in min/max range and that the block hash is less than the
// target difficulty as claimed.
func CheckProofOfWork(block *btcutil.Block, powLimit *big.Int) error {
	return checkProofOfWork(&block.MsgBlock().Header, powLimit, BFNone)
}

//.........这里部分代码省略.........
	for _, txOut := range transactions[0].MsgTx().TxOut {
		totalSatoshiOut += txOut.Value
	}
	expectedSatoshiOut := CalcBlockSubsidy(node.height, b.chainParams) +
		totalFees
	if totalSatoshiOut > expectedSatoshiOut {
		str := fmt.Sprintf("coinbase transaction for block pays %v "+
			"which is more than expected value of %v",
			totalSatoshiOut, expectedSatoshiOut)
		return ruleError(ErrBadCoinbaseValue, str)
	}

	// Don't run scripts if this node is before the latest known good
	// checkpoint since the validity is verified via the checkpoints (all
	// transactions are included in the merkle root hash and any changes
	// will therefore be detected by the next checkpoint).  This is a huge
	// optimization because running the scripts is the most time consuming
	// portion of block handling.
	checkpoint := b.latestCheckpoint()
	runScripts := !b.noVerify
	if checkpoint != nil && node.height <= checkpoint.Height {
		runScripts = false
	}

	// Blocks created after the BIP0016 activation time need to have the
	// pay-to-script-hash checks enabled.
	var scriptFlags txscript.ScriptFlags
	if enforceBIP0016 {
		scriptFlags |= txscript.ScriptBip16
	}

	// Enforce DER signatures for block versions 3+ once the historical
	// activation threshold has been reached.  This is part of BIP0066.
	blockHeader := &block.MsgBlock().Header
	if blockHeader.Version >= 3 && node.height >= b.chainParams.BIP0066Height {
		scriptFlags |= txscript.ScriptVerifyDERSignatures
	}

	// Enforce CHECKLOCKTIMEVERIFY for block versions 4+ once the historical
	// activation threshold has been reached.  This is part of BIP0065.
	if blockHeader.Version >= 4 && node.height >= b.chainParams.BIP0065Height {
		scriptFlags |= txscript.ScriptVerifyCheckLockTimeVerify
	}

	// Enforce the segwit soft-fork package once the soft-fork has shifted
	// into the "active" version bits state.
	if enforceSegWit {
		scriptFlags |= txscript.ScriptVerifyWitness
		scriptFlags |= txscript.ScriptStrictMultiSig
	}

	// Enforce CHECKSEQUENCEVERIFY during all block validation checks once
	// the soft-fork deployment is fully active.
	csvState, err := b.deploymentState(node.parent, chaincfg.DeploymentCSV)
	if err != nil {
		return err
	}
	if csvState == ThresholdActive {
		// If the CSV soft-fork is now active, then modify the
		// scriptFlags to ensure that the CSV op code is properly
		// validated during the script checks bleow.
		scriptFlags |= txscript.ScriptVerifyCheckSequenceVerify

		// We obtain the MTP of the *previous* block in order to
		// determine if transactions in the current block are final.
		medianTime, err := b.calcPastMedianTime(node.parent)

// ProcessBlock is the main workhorse for handling insertion of new blocks into
// the block chain.  It includes functionality such as rejecting duplicate
// blocks, ensuring blocks follow all rules, orphan handling, and insertion into
// the block chain along with best chain selection and reorganization.
//
// When no errors occurred during processing, the first return value indicates
// whether or not the block is on the main chain and the second indicates
// whether or not the block is an orphan.
//
// This function is safe for concurrent access.
func (b *BlockChain) ProcessBlock(block *btcutil.Block, flags BehaviorFlags) (bool, bool, error) {
	b.chainLock.Lock()
	defer b.chainLock.Unlock()

	fastAdd := flags&BFFastAdd == BFFastAdd
	dryRun := flags&BFDryRun == BFDryRun

	blockHash := block.Hash()
	log.Tracef("Processing block %v", blockHash)

	// The block must not already exist in the main chain or side chains.
	exists, err := b.blockExists(blockHash)
	if err != nil {
		return false, false, err
	}
	if exists {
		str := fmt.Sprintf("already have block %v", blockHash)
		return false, false, ruleError(ErrDuplicateBlock, str)
	}

	// The block must not already exist as an orphan.
	if _, exists := b.orphans[*blockHash]; exists {
		str := fmt.Sprintf("already have block (orphan) %v", blockHash)
		return false, false, ruleError(ErrDuplicateBlock, str)
	}

	// Perform preliminary sanity checks on the block and its transactions.
	err = checkBlockSanity(block, b.chainParams.PowLimit, b.timeSource, flags)
	if err != nil {
		return false, false, err
	}

	// Find the previous checkpoint and perform some additional checks based
	// on the checkpoint.  This provides a few nice properties such as
	// preventing old side chain blocks before the last checkpoint,
	// rejecting easy to mine, but otherwise bogus, blocks that could be
	// used to eat memory, and ensuring expected (versus claimed) proof of
	// work requirements since the previous checkpoint are met.
	blockHeader := &block.MsgBlock().Header
	checkpointBlock, err := b.findPreviousCheckpoint()
	if err != nil {
		return false, false, err
	}
	if checkpointBlock != nil {
		// Ensure the block timestamp is after the checkpoint timestamp.
		checkpointHeader := &checkpointBlock.MsgBlock().Header
		checkpointTime := checkpointHeader.Timestamp
		if blockHeader.Timestamp.Before(checkpointTime) {
			str := fmt.Sprintf("block %v has timestamp %v before "+
				"last checkpoint timestamp %v", blockHash,
				blockHeader.Timestamp, checkpointTime)
			return false, false, ruleError(ErrCheckpointTimeTooOld, str)
		}
		if !fastAdd {
			// Even though the checks prior to now have already ensured the
			// proof of work exceeds the claimed amount, the claimed amount
			// is a field in the block header which could be forged.  This
			// check ensures the proof of work is at least the minimum
			// expected based on elapsed time since the last checkpoint and
			// maximum adjustment allowed by the retarget rules.
			duration := blockHeader.Timestamp.Sub(checkpointTime)
			requiredTarget := CompactToBig(b.calcEasiestDifficulty(
				checkpointHeader.Bits, duration))
			currentTarget := CompactToBig(blockHeader.Bits)
			if currentTarget.Cmp(requiredTarget) > 0 {
				str := fmt.Sprintf("block target difficulty of %064x "+
					"is too low when compared to the previous "+
					"checkpoint", currentTarget)
				return false, false, ruleError(ErrDifficultyTooLow, str)
			}
		}
	}

	// Handle orphan blocks.
	prevHash := &blockHeader.PrevBlock
	prevHashExists, err := b.blockExists(prevHash)
	if err != nil {
		return false, false, err
	}
	if !prevHashExists {
		if !dryRun {
			log.Infof("Adding orphan block %v with parent %v",
				blockHash, prevHash)
			b.addOrphanBlock(block)
		}

		return false, true, nil
	}

	// The block has passed all context independent checks and appears sane
//.........这里部分代码省略.........