Golang Block.Transactions方法代码示例

// disconnectTransactions updates the passed map by undoing transaction and
// spend information for all transactions in the passed block.  Only
// transactions in the passed map are updated.
func disconnectTransactions(txStore TxStore, block *coinutil.Block) error {
	// Loop through all of the transactions in the block to see if any of
	// them are ones that need to be undone based on the transaction store.
	for _, tx := range block.Transactions() {
		// Clear this transaction from the transaction store if needed.
		// Only clear it rather than deleting it because the transaction
		// connect code relies on its presence to decide whether or not
		// to update the store and any transactions which exist on both
		// sides of a fork would otherwise not be updated.
		if txD, exists := txStore[*tx.Sha()]; exists {
			txD.Tx = nil
			txD.BlockHeight = 0
			txD.Spent = nil
			txD.Err = database.ErrTxShaMissing
		}

		// Unspend the origin transaction output.
		for _, txIn := range tx.MsgTx().TxIn {
			originHash := &txIn.PreviousOutPoint.Hash
			originIndex := txIn.PreviousOutPoint.Index
			originTx, exists := txStore[*originHash]
			if exists && originTx.Tx != nil && originTx.Err == nil {
				if originIndex > uint32(len(originTx.Spent)) {
					continue
				}
				originTx.Spent[originIndex] = false
			}
		}
	}

	return nil
}

// checkBlockScripts executes and validates the scripts for all transactions in
// the passed block.
func checkBlockScripts(block *coinutil.Block, txStore TxStore,
	scriptFlags txscript.ScriptFlags, sigCache *txscript.SigCache) error {

	// Collect all of the transaction inputs and required information for
	// validation for all transactions in the block into a single slice.
	numInputs := 0
	for _, tx := range block.Transactions() {
		numInputs += len(tx.MsgTx().TxIn)
	}
	txValItems := make([]*txValidateItem, 0, numInputs)
	for _, tx := range block.Transactions() {
		for txInIdx, txIn := range tx.MsgTx().TxIn {
			// Skip coinbases.
			if txIn.PreviousOutPoint.Index == math.MaxUint32 {
				continue
			}

			txVI := &txValidateItem{
				txInIndex: txInIdx,
				txIn:      txIn,
				tx:        tx,
			}
			txValItems = append(txValItems, txVI)
		}
	}

	// Validate all of the inputs.
	validator := newTxValidator(txStore, scriptFlags, sigCache)
	if err := validator.Validate(txValItems); err != nil {
		return err
	}

	return nil
}

// connectTransactions updates the passed map by applying transaction and
// spend information for all the transactions in the passed block.  Only
// transactions in the passed map are updated.
func connectTransactions(txStore TxStore, block *coinutil.Block) error {
	// Loop through all of the transactions in the block to see if any of
	// them are ones we need to update and spend based on the results map.
	for _, tx := range block.Transactions() {
		// Update the transaction store with the transaction information
		// if it's one of the requested transactions.
		msgTx := tx.MsgTx()
		if txD, exists := txStore[*tx.Sha()]; exists {
			txD.Tx = tx
			txD.BlockHeight = block.Height()
			txD.Spent = make([]bool, len(msgTx.TxOut))
			txD.Err = nil
		}

		// Spend the origin transaction output.
		for _, txIn := range msgTx.TxIn {
			originHash := &txIn.PreviousOutPoint.Hash
			originIndex := txIn.PreviousOutPoint.Index
			if originTx, exists := txStore[*originHash]; exists {
				if originIndex > uint32(len(originTx.Spent)) {
					continue
				}
				originTx.Spent[originIndex] = true
			}
		}
	}

	return nil
}

// DropAfterBlockBySha will remove any blocks from the database after
// the given block.
func (db *LevelDb) DropAfterBlockBySha(sha *wire.ShaHash) (rerr error) {
	db.dbLock.Lock()
	defer db.dbLock.Unlock()
	defer func() {
		if rerr == nil {
			rerr = db.processBatches()
		} else {
			db.lBatch().Reset()
		}
	}()

	startheight := db.nextBlock - 1

	keepidx, err := db.getBlkLoc(sha)
	if err != nil {
		// should the error here be normalized ?
		log.Tracef("block loc failed %v ", sha)
		return err
	}

	for height := startheight; height > keepidx; height = height - 1 {
		var blk *coinutil.Block
		blksha, buf, err := db.getBlkByHeight(height)
		if err != nil {
			return err
		}
		blk, err = coinutil.NewBlockFromBytes(buf)
		if err != nil {
			return err
		}

		for _, tx := range blk.MsgBlock().Transactions {
			err = db.unSpend(tx)
			if err != nil {
				return err
			}
		}
		// rather than iterate the list of tx backward, do it twice.
		for _, tx := range blk.Transactions() {
			var txUo txUpdateObj
			txUo.delete = true
			db.txUpdateMap[*tx.Sha()] = &txUo
		}
		db.lBatch().Delete(shaBlkToKey(blksha))
		db.lBatch().Delete(int64ToKey(int64(height)))
	}

	// update the last block cache
	db.lastBlkShaCached = true
	db.lastBlkSha = *sha
	db.lastBlkIdx = keepidx
	db.nextBlock = keepidx + 1

	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.
func (b *BlockChain) checkBlockContext(block *coinutil.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
	}

	fastAdd := flags&BFFastAdd == BFFastAdd
	if !fastAdd {
		// 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,
				header.Timestamp) {

				str := fmt.Sprintf("block contains unfinalized "+
					"transaction %v", tx.Sha())
				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) &&
			b.isMajorityVersion(serializedHeightVersion, prevNode,
				b.chainParams.BlockEnforceNumRequired) {

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

	return nil
}

// NewMerkleBlock returns a new *wire.MsgMerkleBlock and an array of the matched
// transaction index numbers based on the passed block and filter.
func NewMerkleBlock(block *coinutil.Block, filter *Filter) (*wire.MsgMerkleBlock, []uint32) {
	numTx := uint32(len(block.Transactions()))
	mBlock := merkleBlock{
		numTx:       numTx,
		allHashes:   make([]*wire.ShaHash, 0, numTx),
		matchedBits: make([]byte, 0, numTx),
	}

	// Find and keep track of any transactions that match the filter.
	var matchedIndices []uint32
	for txIndex, tx := range block.Transactions() {
		if filter.MatchTxAndUpdate(tx) {
			mBlock.matchedBits = append(mBlock.matchedBits, 0x01)
			matchedIndices = append(matchedIndices, uint32(txIndex))
		} else {
			mBlock.matchedBits = append(mBlock.matchedBits, 0x00)
		}
		mBlock.allHashes = append(mBlock.allHashes, tx.Sha())
	}

	// Calculate the number of merkle branches (height) in the tree.
	height := uint32(0)
	for mBlock.calcTreeWidth(height) > 1 {
		height++
	}

	// Build the depth-first partial merkle tree.
	mBlock.traverseAndBuild(height, 0)

	// Create and return the merkle block.
	msgMerkleBlock := wire.MsgMerkleBlock{
		Header:       block.MsgBlock().Header,
		Transactions: uint32(mBlock.numTx),
		Hashes:       make([]*wire.ShaHash, 0, len(mBlock.finalHashes)),
		Flags:        make([]byte, (len(mBlock.bits)+7)/8),
	}
	for _, sha := range mBlock.finalHashes {
		msgMerkleBlock.AddTxHash(sha)
	}
	for i := uint32(0); i < uint32(len(mBlock.bits)); i++ {
		msgMerkleBlock.Flags[i/8] |= mBlock.bits[i] << (i % 8)
	}
	return &msgMerkleBlock, matchedIndices
}

// indexBlockAddrs returns a populated index of the all the transactions in the
// passed block based on the addresses involved in each transaction.
func (a *addrIndexer) indexBlockAddrs(blk *coinutil.Block) (database.BlockAddrIndex, error) {
	addrIndex := make(database.BlockAddrIndex)
	txLocs, err := blk.TxLoc()
	if err != nil {
		return nil, err
	}

	for txIdx, tx := range blk.Transactions() {
		// Tx's offset and length in the block.
		locInBlock := &txLocs[txIdx]

		// Coinbases don't have any inputs.
		if !blockchain.IsCoinBase(tx) {
			// Index the SPK's of each input's previous outpoint
			// transaction.
			for _, txIn := range tx.MsgTx().TxIn {
				// Lookup and fetch the referenced output's tx.
				prevOut := txIn.PreviousOutPoint
				txList, err := a.server.db.FetchTxBySha(&prevOut.Hash)
				if len(txList) == 0 {
					return nil, fmt.Errorf("transaction %v not found",
						prevOut.Hash)
				}
				if err != nil {
					adxrLog.Errorf("Error fetching tx %v: %v",
						prevOut.Hash, err)
					return nil, err
				}
				prevOutTx := txList[len(txList)-1]
				inputOutPoint := prevOutTx.Tx.TxOut[prevOut.Index]

				indexScriptPubKey(addrIndex, inputOutPoint.PkScript, locInBlock)
			}
		}

		for _, txOut := range tx.MsgTx().TxOut {
			indexScriptPubKey(addrIndex, txOut.PkScript, locInBlock)
		}
	}
	return addrIndex, nil
}

// checkBIP0030 ensures blocks do not contain duplicate transactions which
// 'overwrite' older transactions that are not fully spent.  This prevents an
// attack where a coinbase and all of its dependent transactions could be
// duplicated to effectively revert the overwritten transactions to a single
// confirmation thereby making them vulnerable to a double spend.
//
// For more details, see https://en.bitcoin.it/wiki/BIP_0030 and
// http://r6.ca/blog/20120206T005236Z.html.
func (b *BlockChain) checkBIP0030(node *blockNode, block *coinutil.Block) error {
	// Attempt to fetch duplicate transactions for all of the transactions
	// in this block from the point of view of the parent node.
	fetchSet := make(map[wire.ShaHash]struct{})
	for _, tx := range block.Transactions() {
		fetchSet[*tx.Sha()] = struct{}{}
	}
	txResults, err := b.fetchTxStore(node, fetchSet)
	if err != nil {
		return err
	}

	// Examine the resulting data about the requested transactions.
	for _, txD := range txResults {
		switch txD.Err {
		// A duplicate transaction was not found.  This is the most
		// common case.
		case database.ErrTxShaMissing:
			continue

		// A duplicate transaction was found.  This is only allowed if
		// the duplicate transaction is fully spent.
		case nil:
			if !isTransactionSpent(txD) {
				str := fmt.Sprintf("tried to overwrite "+
					"transaction %v at block height %d "+
					"that is not fully spent", txD.Hash,
					txD.BlockHeight)
				return ruleError(ErrOverwriteTx, str)
			}

		// Some other unexpected error occurred.  Return it now.
		default:
			return txD.Err
		}
	}

	return nil
}

// InsertBlock inserts raw block and transaction data from a block into the
// database.  The first block inserted into the database will be treated as the
// genesis block.  Every subsequent block insert requires the referenced parent
// block to already exist.  This is part of the database.Db interface
// implementation.
func (db *MemDb) InsertBlock(block *coinutil.Block) (int32, error) {
	db.Lock()
	defer db.Unlock()

	if db.closed {
		return 0, ErrDbClosed
	}

	// Reject the insert if the previously reference block does not exist
	// except in the case there are no blocks inserted yet where the first
	// inserted block is assumed to be a genesis block.
	msgBlock := block.MsgBlock()
	if _, exists := db.blocksBySha[msgBlock.Header.PrevBlock]; !exists {
		if len(db.blocks) > 0 {
			return 0, database.ErrPrevShaMissing
		}
	}

	// Build a map of in-flight transactions because some of the inputs in
	// this block could be referencing other transactions earlier in this
	// block which are not yet in the chain.
	txInFlight := map[wire.ShaHash]int{}
	transactions := block.Transactions()
	for i, tx := range transactions {
		txInFlight[*tx.Sha()] = i
	}

	// Loop through all transactions and inputs to ensure there are no error
	// conditions that would prevent them from be inserted into the db.
	// Although these checks could could be done in the loop below, checking
	// for error conditions up front means the code below doesn't have to
	// deal with rollback on errors.
	newHeight := int32(len(db.blocks))
	for i, tx := range transactions {
		// Two old blocks contain duplicate transactions due to being
		// mined by faulty miners and accepted by the origin Satoshi
		// client.  Rules have since been added to the ensure this
		// problem can no longer happen, but the two duplicate
		// transactions which were originally accepted are forever in
		// the block chain history and must be dealth with specially.
		// http://blockexplorer.com/b/91842
		// http://blockexplorer.com/b/91880
		if newHeight == 91842 && tx.Sha().IsEqual(dupTxHash91842) {
			continue
		}

		if newHeight == 91880 && tx.Sha().IsEqual(dupTxHash91880) {
			continue
		}

		for _, txIn := range tx.MsgTx().TxIn {
			if isCoinbaseInput(txIn) {
				continue
			}

			// It is acceptable for a transaction input to reference
			// the output of another transaction in this block only
			// if the referenced transaction comes before the
			// current one in this block.
			prevOut := &txIn.PreviousOutPoint
			if inFlightIndex, ok := txInFlight[prevOut.Hash]; ok {
				if i <= inFlightIndex {
					log.Warnf("InsertBlock: requested hash "+
						" of %s does not exist in-flight",
						tx.Sha())
					return 0, database.ErrTxShaMissing
				}
			} else {
				originTxns, exists := db.txns[prevOut.Hash]
				if !exists {
					log.Warnf("InsertBlock: requested hash "+
						"of %s by %s does not exist",
						prevOut.Hash, tx.Sha())
					return 0, database.ErrTxShaMissing
				}
				originTxD := originTxns[len(originTxns)-1]
				if prevOut.Index > uint32(len(originTxD.spentBuf)) {
					log.Warnf("InsertBlock: requested hash "+
						"of %s with index %d does not "+
						"exist", tx.Sha(), prevOut.Index)
					return 0, database.ErrTxShaMissing
				}
			}
		}

		// Prevent duplicate transactions in the same block.
		if inFlightIndex, exists := txInFlight[*tx.Sha()]; exists &&
			inFlightIndex < i {
			log.Warnf("Block contains duplicate transaction %s",
				tx.Sha())
			return 0, database.ErrDuplicateSha
		}

		// Prevent duplicate transactions unless the old one is fully
		// spent.
//.........这里部分代码省略.........

// fetchInputTransactions fetches the input transactions referenced by the
// transactions in the given block from its point of view.  See fetchTxList
// for more details on what the point of view entails.
func (b *BlockChain) fetchInputTransactions(node *blockNode, block *coinutil.Block) (TxStore, error) {
	// Build a map of in-flight transactions because some of the inputs in
	// this block could be referencing other transactions earlier in this
	// block which are not yet in the chain.
	txInFlight := map[wire.ShaHash]int{}
	transactions := block.Transactions()
	for i, tx := range transactions {
		txInFlight[*tx.Sha()] = i
	}

	// Loop through all of the transaction inputs (except for the coinbase
	// which has no inputs) collecting them into sets of what is needed and
	// what is already known (in-flight).
	txNeededSet := make(map[wire.ShaHash]struct{})
	txStore := make(TxStore)
	for i, tx := range transactions[1:] {
		for _, txIn := range tx.MsgTx().TxIn {
			// Add an entry to the transaction store for the needed
			// transaction with it set to missing by default.
			originHash := &txIn.PreviousOutPoint.Hash
			txD := &TxData{Hash: originHash, Err: database.ErrTxShaMissing}
			txStore[*originHash] = txD

			// It is acceptable for a transaction input to reference
			// the output of another transaction in this block only
			// if the referenced transaction comes before the
			// current one in this block.  Update the transaction
			// store acccordingly when this is the case.  Otherwise,
			// we still need the transaction.
			//
			// NOTE: The >= is correct here because i is one less
			// than the actual position of the transaction within
			// the block due to skipping the coinbase.
			if inFlightIndex, ok := txInFlight[*originHash]; ok &&
				i >= inFlightIndex {

				originTx := transactions[inFlightIndex]
				txD.Tx = originTx
				txD.BlockHeight = node.height
				txD.Spent = make([]bool, len(originTx.MsgTx().TxOut))
				txD.Err = nil
			} else {
				txNeededSet[*originHash] = struct{}{}
			}
		}
	}

	// Request the input transactions from the point of view of the node.
	txNeededStore, err := b.fetchTxStore(node, txNeededSet)
	if err != nil {
		return nil, err
	}

	// Merge the results of the requested transactions and the in-flight
	// transactions.
	for _, txD := range txNeededStore {
		txStore[*txD.Hash] = txD
	}

	return txStore, nil
}

// 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.
func (b *BlockChain) IsCheckpointCandidate(block *coinutil.Block) (bool, error) {
	// Checkpoints must be enabled.
	if b.noCheckpoints {
		return false, fmt.Errorf("checkpoints are disabled")
	}

	// A checkpoint must be in the main chain.
	exists, err := b.db.ExistsSha(block.Sha())
	if err != nil {
		return false, err
	}
	if !exists {
		return false, nil
	}

	// A checkpoint must be at least CheckpointConfirmations blocks before
	// the end of the main chain.
	blockHeight := block.Height()
	_, mainChainHeight, err := b.db.NewestSha()
	if err != nil {
		return false, err
	}
	if blockHeight > (mainChainHeight - CheckpointConfirmations) {
		return false, nil
	}

	// Get the previous block.
	prevHash := &block.MsgBlock().Header.PrevBlock
	prevBlock, err := b.db.FetchBlockBySha(prevHash)
	if err != nil {
		return false, err
	}

	// Get the next block.
	nextHash, err := b.db.FetchBlockShaByHeight(blockHeight + 1)
	if err != nil {
		return false, err
	}
	nextBlock, err := b.db.FetchBlockBySha(nextHash)
	if err != nil {
		return false, 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 := prevBlock.MsgBlock().Header.Timestamp
	curTime := block.MsgBlock().Header.Timestamp
	nextTime := nextBlock.MsgBlock().Header.Timestamp
	if prevTime.After(curTime) || nextTime.Before(curTime) {
		return false, nil
	}

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

	return true, nil
}

// checkConnectBlock performs several checks to confirm connecting the passed
// block to the main chain (including whatever reorganization might be necessary
// to get this node to the main chain) does not violate any rules.
//
// The CheckConnectBlock function makes use of this function to perform the
// bulk of its work.  The only difference is this function accepts a node which
// may or may not require reorganization to connect it to the main chain whereas
// CheckConnectBlock creates a new node which specifically connects to the end
// of the current main chain and then calls this function with that node.
//
// See the comments for CheckConnectBlock for some examples of the type of
// checks performed by this function.
func (b *BlockChain) checkConnectBlock(node *blockNode, block *coinutil.Block) error {
	// If the side chain blocks end up in the database, a call to
	// CheckBlockSanity should be done here in case a previous version
	// allowed a block that is no longer valid.  However, since the
	// implementation only currently uses memory for the side chain blocks,
	// it isn't currently necessary.

	// The coinbase for the Genesis block is not spendable, so just return
	// now.
	if node.hash.IsEqual(b.chainParams.GenesisHash) && b.bestChain == nil {
		return nil
	}

	// BIP0030 added a rule to prevent blocks which contain duplicate
	// transactions that 'overwrite' older transactions which are not fully
	// spent.  See the documentation for checkBIP0030 for more details.
	//
	// There are two blocks in the chain which violate this
	// rule, so the check must be skipped for those blocks. The
	// isBIP0030Node function is used to determine if this block is one
	// of the two blocks that must be skipped.
	enforceBIP0030 := !isBIP0030Node(node)
	if enforceBIP0030 {
		err := b.checkBIP0030(node, block)
		if err != nil {
			return err
		}
	}

	// Request a map that contains all input transactions for the block from
	// the point of view of its position within the block chain.  These
	// transactions are needed for verification of things such as
	// transaction inputs, counting pay-to-script-hashes, and scripts.
	txInputStore, err := b.fetchInputTransactions(node, block)
	if err != nil {
		return err
	}

	// BIP0016 describes a pay-to-script-hash type that is considered a
	// "standard" type.  The rules for this BIP only apply to transactions
	// after the timestamp defined by txscript.Bip16Activation.  See
	// https://en.bitcoin.it/wiki/BIP_0016 for more details.
	enforceBIP0016 := false
	if node.timestamp.After(txscript.Bip16Activation) {
		enforceBIP0016 = true
	}

	// The number of signature operations must be less than the maximum
	// allowed per block.  Note that the preliminary sanity checks on a
	// block also include a check similar to this one, but this check
	// expands the count to include a precise count of pay-to-script-hash
	// signature operations in each of the input transaction public key
	// scripts.
	transactions := block.Transactions()
	totalSigOps := 0
	for i, tx := range transactions {
		numsigOps := CountSigOps(tx)
		if enforceBIP0016 {
			// Since the first (and only the first) transaction has
			// already been verified to be a coinbase transaction,
			// use i == 0 as an optimization for the flag to
			// countP2SHSigOps for whether or not the transaction is
			// a coinbase transaction rather than having to do a
			// full coinbase check again.
			numP2SHSigOps, err := CountP2SHSigOps(tx, i == 0,
				txInputStore)
			if err != nil {
				return err
			}
			numsigOps += numP2SHSigOps
		}

		// Check for overflow or going over the limits.  We have to do
		// this on every loop iteration to avoid overflow.
		lastSigops := totalSigOps
		totalSigOps += numsigOps
		if totalSigOps < lastSigops || totalSigOps > MaxSigOpsPerBlock {
			str := fmt.Sprintf("block contains too many "+
				"signature operations - got %v, max %v",
				totalSigOps, MaxSigOpsPerBlock)
			return ruleError(ErrTooManySigOps, str)
		}
	}

	// Perform several checks on the inputs for each transaction.  Also
	// accumulate the total fees.  This could technically be combined with
	// the loop above instead of running another loop over the transactions,
	// but by separating it we can avoid running the more expensive (though
//.........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 *coinutil.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.SerializeSize()
	if serializedSize > wire.MaxBlockPayload {
		str := fmt.Sprintf("serialized block is too big - got %d, "+
			"max %d", serializedSize, wire.MaxBlockPayload)
		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)
			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())
	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[wire.ShaHash]struct{})
	for _, tx := range transactions {
		hash := tx.Sha()
		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)
		if totalSigOps < lastSigOps || totalSigOps > MaxSigOpsPerBlock {
			str := fmt.Sprintf("block contains too many signature "+
//.........这里部分代码省略.........