Golang Tx.Sha方法代碼示例

// CountP2SHSigOps returns the number of signature operations for all input
// transactions which are of the pay-to-script-hash type.  This uses the
// precise, signature operation counting mechanism from the script engine which
// requires access to the input transaction scripts.
func CountP2SHSigOps(tx *btcutil.Tx, isCoinBaseTx bool, txStore TxStore) (int, error) {
	// Coinbase transactions have no interesting inputs.
	if isCoinBaseTx {
		return 0, nil
	}

	// Accumulate the number of signature operations in all transaction
	// inputs.
	msgTx := tx.MsgTx()
	totalSigOps := 0
	for _, txIn := range msgTx.TxIn {
		// Ensure the referenced input transaction is available.
		txInHash := &txIn.PreviousOutPoint.Hash
		originTx, exists := txStore[*txInHash]
		if !exists || originTx.Err != nil || originTx.Tx == nil {
			str := fmt.Sprintf("unable to find input transaction "+
				"%v referenced from transaction %v", txInHash,
				tx.Sha())
			return 0, ruleError(ErrMissingTx, str)
		}
		originMsgTx := originTx.Tx.MsgTx()

		// Ensure the output index in the referenced transaction is
		// available.
		originTxIndex := txIn.PreviousOutPoint.Index
		if originTxIndex >= uint32(len(originMsgTx.TxOut)) {
			str := fmt.Sprintf("out of bounds input index %d in "+
				"transaction %v referenced from transaction %v",
				originTxIndex, txInHash, tx.Sha())
			return 0, ruleError(ErrBadTxInput, str)
		}

		// We're only interested in pay-to-script-hash types, so skip
		// this input if it's not one.
		pkScript := originMsgTx.TxOut[originTxIndex].PkScript
		if !txscript.IsPayToScriptHash(pkScript) {
			continue
		}

		// Count the precise number of signature operations in the
		// referenced public key script.
		sigScript := txIn.SignatureScript
		numSigOps := txscript.GetPreciseSigOpCount(sigScript, pkScript,
			true)

		// We could potentially overflow the accumulator so check for
		// overflow.
		lastSigOps := totalSigOps
		totalSigOps += numSigOps
		if totalSigOps < lastSigOps {
			str := fmt.Sprintf("the public key script from "+
				"output index %d in transaction %v contains "+
				"too many signature operations - overflow",
				originTxIndex, txInHash)
			return 0, ruleError(ErrTooManySigOps, str)
		}
	}

	return totalSigOps, nil
}

// removeTransaction is the internal function which implements the public
// RemoveTransaction.  See the comment for RemoveTransaction for more details.
//
// This function MUST be called with the mempool lock held (for writes).
func (mp *txMemPool) removeTransaction(tx *btcutil.Tx, removeRedeemers bool) {
	txHash := tx.Sha()
	if removeRedeemers {
		// Remove any transactions which rely on this one.
		for i := uint32(0); i < uint32(len(tx.MsgTx().TxOut)); i++ {
			outpoint := wire.NewOutPoint(txHash, i)
			if txRedeemer, exists := mp.outpoints[*outpoint]; exists {
				mp.removeTransaction(txRedeemer, true)
			}
		}
	}

	// Remove the transaction and mark the referenced outpoints as unspent
	// by the pool.
	if txDesc, exists := mp.pool[*txHash]; exists {
		if mp.cfg.EnableAddrIndex {
			mp.removeTransactionFromAddrIndex(tx)
		}

		for _, txIn := range txDesc.Tx.MsgTx().TxIn {
			delete(mp.outpoints, txIn.PreviousOutPoint)
		}
		delete(mp.pool, *txHash)
		mp.lastUpdated = time.Now()
	}

}

// logSkippedDeps logs any dependencies which are also skipped as a result of
// skipping a transaction while generating a block template at the trace level.
func logSkippedDeps(tx *btcutil.Tx, deps *list.List) {
	if deps == nil {
		return
	}

	for e := deps.Front(); e != nil; e = e.Next() {
		item := e.Value.(*txPrioItem)
		minrLog.Tracef("Skipping tx %s since it depends on %s\n",
			item.tx.Sha(), tx.Sha())
	}
}

// RemoveDoubleSpends removes all transactions which spend outputs spent by the
// passed transaction from the memory pool.  Removing those transactions then
// leads to removing all transactions which rely on them, recursively.  This is
// necessary when a block is connected to the main chain because the block may
// contain transactions which were previously unknown to the memory pool
//
// This function is safe for concurrent access.
func (mp *txMemPool) RemoveDoubleSpends(tx *btcutil.Tx) {
	// Protect concurrent access.
	mp.Lock()
	defer mp.Unlock()

	for _, txIn := range tx.MsgTx().TxIn {
		if txRedeemer, ok := mp.outpoints[txIn.PreviousOutPoint]; ok {
			if !txRedeemer.Sha().IsEqual(tx.Sha()) {
				mp.removeTransaction(txRedeemer, true)
			}
		}
	}
}

// removeScriptFromAddrIndex dissociates the address encoded by the
// passed pkScript from the passed tx in our address based tx index.
//
// This function MUST be called with the mempool lock held (for writes).
func (mp *txMemPool) removeScriptFromAddrIndex(pkScript []byte, tx *btcutil.Tx) error {
	_, addresses, _, err := txscript.ExtractPkScriptAddrs(pkScript,
		activeNetParams.Params)
	if err != nil {
		txmpLog.Errorf("Unable to extract encoded addresses from script "+
			"for addrindex (addrindex): %v", err)
		return err
	}
	for _, addr := range addresses {
		delete(mp.addrindex[addr.EncodeAddress()], *tx.Sha())
	}

	return nil
}

// FetchTransactionStore fetches the input transactions referenced by the
// passed transaction from the point of view of the end of the main chain.  It
// also attempts to fetch the transaction itself so the returned TxStore can be
// examined for duplicate transactions.
func (b *BlockChain) FetchTransactionStore(tx *btcutil.Tx, includeSpent bool) (TxStore, error) {
	// Create a set of needed transactions from the transactions referenced
	// by the inputs of the passed transaction.  Also, add the passed
	// transaction itself as a way for the caller to detect duplicates.
	txNeededSet := make(map[wire.ShaHash]struct{})
	txNeededSet[*tx.Sha()] = struct{}{}
	for _, txIn := range tx.MsgTx().TxIn {
		txNeededSet[txIn.PreviousOutPoint.Hash] = struct{}{}
	}

	// Request the input transactions from the point of view of the end of
	// the main chain with or without without including fully spent transactions
	// in the results.
	txStore := fetchTxStoreMain(b.db, txNeededSet, includeSpent)
	return txStore, nil
}

// indexScriptByAddress alters our address index by indexing the payment address
// encoded by the passed scriptPubKey to the passed transaction.
//
// This function MUST be called with the mempool lock held (for writes).
func (mp *txMemPool) indexScriptAddressToTx(pkScript []byte, tx *btcutil.Tx) error {
	_, addresses, _, err := txscript.ExtractPkScriptAddrs(pkScript,
		activeNetParams.Params)
	if err != nil {
		txmpLog.Errorf("Unable to extract encoded addresses from script "+
			"for addrindex: %v", err)
		return err
	}

	for _, addr := range addresses {
		if mp.addrindex[addr.EncodeAddress()] == nil {
			mp.addrindex[addr.EncodeAddress()] = make(map[wire.ShaHash]struct{})
		}
		mp.addrindex[addr.EncodeAddress()][*tx.Sha()] = struct{}{}
	}

	return nil
}

// spendTransaction updates the passed transaction store by marking the inputs
// to the passed transaction as spent.  It also adds the passed transaction to
// the store at the provided height.
func spendTransaction(txStore blockchain.TxStore, tx *btcutil.Tx, height int32) error {
	for _, txIn := range tx.MsgTx().TxIn {
		originHash := &txIn.PreviousOutPoint.Hash
		originIndex := txIn.PreviousOutPoint.Index
		if originTx, exists := txStore[*originHash]; exists {
			originTx.Spent[originIndex] = true
		}
	}

	txStore[*tx.Sha()] = &blockchain.TxData{
		Tx:          tx,
		Hash:        tx.Sha(),
		BlockHeight: height,
		Spent:       make([]bool, len(tx.MsgTx().TxOut)),
		Err:         nil,
	}

	return nil
}

// addTransaction adds the passed transaction to the memory pool.  It should
// not be called directly as it doesn't perform any validation.  This is a
// helper for maybeAcceptTransaction.
//
// This function MUST be called with the mempool lock held (for writes).
func (mp *txMemPool) addTransaction(txStore blockchain.TxStore, tx *btcutil.Tx, height int32, fee int64) {
	// Add the transaction to the pool and mark the referenced outpoints
	// as spent by the pool.
	mp.pool[*tx.Sha()] = &mempoolTxDesc{
		TxDesc: mining.TxDesc{
			Tx:     tx,
			Added:  time.Now(),
			Height: height,
			Fee:    fee,
		},
		StartingPriority: calcPriority(tx.MsgTx(), txStore, height),
	}
	for _, txIn := range tx.MsgTx().TxIn {
		mp.outpoints[txIn.PreviousOutPoint] = tx
	}
	mp.lastUpdated = time.Now()

	if mp.cfg.EnableAddrIndex {
		mp.addTransactionToAddrIndex(tx)
	}
}

// ProcessTransaction is the main workhorse for handling insertion of new
// free-standing transactions into the memory pool.  It includes functionality
// such as rejecting duplicate transactions, ensuring transactions follow all
// rules, orphan transaction handling, and insertion into the memory pool.
//
// This function is safe for concurrent access.
func (mp *txMemPool) ProcessTransaction(tx *btcutil.Tx, allowOrphan, rateLimit bool) error {
	// Protect concurrent access.
	mp.Lock()
	defer mp.Unlock()

	txmpLog.Tracef("Processing transaction %v", tx.Sha())

	// Potentially accept the transaction to the memory pool.
	missingParents, err := mp.maybeAcceptTransaction(tx, true, rateLimit)
	if err != nil {
		return err
	}

	if len(missingParents) == 0 {
		// Notify the caller that the tx was added to the mempool.
		if mp.cfg.RelayNtfnChan != nil {
			mp.cfg.RelayNtfnChan <- tx
		}

		// Accept any orphan transactions that depend on this
		// transaction (they may no longer be orphans if all inputs
		// are now available) and repeat for those accepted
		// transactions until there are no more.
		mp.processOrphans(tx.Sha())
	} else {
		// The transaction is an orphan (has inputs missing).  Reject
		// it if the flag to allow orphans is not set.
		if !allowOrphan {
			// Only use the first missing parent transaction in
			// the error message.
			//
			// NOTE: RejectDuplicate is really not an accurate
			// reject code here, but it matches the reference
			// implementation and there isn't a better choice due
			// to the limited number of reject codes.  Missing
			// inputs is assumed to mean they are already spent
			// which is not really always the case.
			str := fmt.Sprintf("orphan transaction %v references "+
				"outputs of unknown or fully-spent "+
				"transaction %v", tx.Sha(), missingParents[0])
			return txRuleError(wire.RejectDuplicate, str)
		}

		// Potentially add the orphan transaction to the orphan pool.
		err := mp.maybeAddOrphan(tx)
		if err != nil {
			return err
		}
	}

	return nil
}

// addOrphan adds an orphan transaction to the orphan pool.
//
// This function MUST be called with the mempool lock held (for writes).
func (mp *txMemPool) addOrphan(tx *btcutil.Tx) {
	// Limit the number orphan transactions to prevent memory exhaustion.  A
	// random orphan is evicted to make room if needed.
	mp.limitNumOrphans()

	mp.orphans[*tx.Sha()] = tx
	for _, txIn := range tx.MsgTx().TxIn {
		originTxHash := txIn.PreviousOutPoint.Hash
		if _, exists := mp.orphansByPrev[originTxHash]; !exists {
			mp.orphansByPrev[originTxHash] =
				make(map[wire.ShaHash]*btcutil.Tx)
		}
		mp.orphansByPrev[originTxHash][*tx.Sha()] = tx
	}

	txmpLog.Debugf("Stored orphan transaction %v (total: %d)", tx.Sha(),
		len(mp.orphans))
}

// CheckTransactionInputs performs a series of checks on the inputs to a
// transaction to ensure they are valid.  An example of some of the checks
// include verifying all inputs exist, ensuring the coinbase seasoning
// requirements are met, detecting double spends, validating all values and fees
// are in the legal range and the total output amount doesn't exceed the input
// amount, and verifying the signatures to prove the spender was the owner of
// the bitcoins and therefore allowed to spend them.  As it checks the inputs,
// it also calculates the total fees for the transaction and returns that value.
func CheckTransactionInputs(tx *btcutil.Tx, txHeight int32, txStore TxStore) (int64, error) {
	// Coinbase transactions have no inputs.
	if IsCoinBase(tx) {
		return 0, nil
	}

	txHash := tx.Sha()
	var totalSatoshiIn int64
	for _, txIn := range tx.MsgTx().TxIn {
		// Ensure the input is available.
		txInHash := &txIn.PreviousOutPoint.Hash
		originTx, exists := txStore[*txInHash]
		if !exists || originTx.Err != nil || originTx.Tx == nil {
			str := fmt.Sprintf("unable to find input transaction "+
				"%v for transaction %v", txInHash, txHash)
			return 0, ruleError(ErrMissingTx, str)
		}

		// Ensure the transaction is not spending coins which have not
		// yet reached the required coinbase maturity.
		if IsCoinBase(originTx.Tx) {
			originHeight := originTx.BlockHeight
			blocksSincePrev := txHeight - originHeight
			if blocksSincePrev < coinbaseMaturity {
				str := fmt.Sprintf("tried to spend coinbase "+
					"transaction %v from height %v at "+
					"height %v before required maturity "+
					"of %v blocks", txInHash, originHeight,
					txHeight, coinbaseMaturity)
				return 0, ruleError(ErrImmatureSpend, str)
			}
		}

		// Ensure the transaction is not double spending coins.
		originTxIndex := txIn.PreviousOutPoint.Index
		if originTxIndex >= uint32(len(originTx.Spent)) {
			str := fmt.Sprintf("out of bounds input index %d in "+
				"transaction %v referenced from transaction %v",
				originTxIndex, txInHash, txHash)
			return 0, ruleError(ErrBadTxInput, str)
		}
		if originTx.Spent[originTxIndex] {
			str := fmt.Sprintf("transaction %v tried to double "+
				"spend output %v", txHash, txIn.PreviousOutPoint)
			return 0, ruleError(ErrDoubleSpend, str)
		}

		// Ensure the transaction amounts are in range.  Each of the
		// output values of the input transactions must not be negative
		// or more than the max allowed per transaction.  All amounts in
		// a transaction are in a unit value known as a satoshi.  One
		// bitcoin is a quantity of satoshi as defined by the
		// SatoshiPerBitcoin constant.
		originTxSatoshi := originTx.Tx.MsgTx().TxOut[originTxIndex].Value
		if originTxSatoshi < 0 {
			str := fmt.Sprintf("transaction output has negative "+
				"value of %v", originTxSatoshi)
			return 0, ruleError(ErrBadTxOutValue, str)
		}
		if originTxSatoshi > btcutil.MaxSatoshi {
			str := fmt.Sprintf("transaction output value of %v is "+
				"higher than max allowed value of %v",
				originTxSatoshi, btcutil.MaxSatoshi)
			return 0, ruleError(ErrBadTxOutValue, str)
		}

		// The total of all outputs must not be more than the max
		// allowed per transaction.  Also, we could potentially overflow
		// the accumulator so check for overflow.
		lastSatoshiIn := totalSatoshiIn
		totalSatoshiIn += originTxSatoshi
		if totalSatoshiIn < lastSatoshiIn ||
			totalSatoshiIn > btcutil.MaxSatoshi {
			str := fmt.Sprintf("total value of all transaction "+
				"inputs is %v which is higher than max "+
				"allowed value of %v", totalSatoshiIn,
				btcutil.MaxSatoshi)
			return 0, ruleError(ErrBadTxOutValue, str)
		}

		// Mark the referenced output as spent.
		originTx.Spent[originTxIndex] = true
	}

	// Calculate the total output amount for this transaction.  It is safe
	// to ignore overflow and out of range errors here because those error
	// conditions would have already been caught by checkTransactionSanity.
	var totalSatoshiOut int64
	for _, txOut := range tx.MsgTx().TxOut {
		totalSatoshiOut += txOut.Value
	}

//.........這裏部分代碼省略.........

// maybeAcceptTransaction is the internal function which implements the public
// MaybeAcceptTransaction.  See the comment for MaybeAcceptTransaction for
// more details.
//
// This function MUST be called with the mempool lock held (for writes).
func (mp *txMemPool) maybeAcceptTransaction(tx *btcutil.Tx, isNew, rateLimit bool) ([]*wire.ShaHash, error) {
	txHash := tx.Sha()

	// Don't accept the transaction if it already exists in the pool.  This
	// applies to orphan transactions as well.  This check is intended to
	// be a quick check to weed out duplicates.
	if mp.haveTransaction(txHash) {
		str := fmt.Sprintf("already have transaction %v", txHash)
		return nil, txRuleError(wire.RejectDuplicate, str)
	}

	// Perform preliminary sanity checks on the transaction.  This makes
	// use of btcchain which contains the invariant rules for what
	// transactions are allowed into blocks.
	err := blockchain.CheckTransactionSanity(tx)
	if err != nil {
		if cerr, ok := err.(blockchain.RuleError); ok {
			return nil, chainRuleError(cerr)
		}
		return nil, err
	}

	// A standalone transaction must not be a coinbase transaction.
	if blockchain.IsCoinBase(tx) {
		str := fmt.Sprintf("transaction %v is an individual coinbase",
			txHash)
		return nil, txRuleError(wire.RejectInvalid, str)
	}

	// Don't accept transactions with a lock time after the maximum int32
	// value for now.  This is an artifact of older bitcoind clients which
	// treated this field as an int32 and would treat anything larger
	// incorrectly (as negative).
	if tx.MsgTx().LockTime > math.MaxInt32 {
		str := fmt.Sprintf("transaction %v has a lock time after "+
			"2038 which is not accepted yet", txHash)
		return nil, txRuleError(wire.RejectNonstandard, str)
	}

	// Get the current height of the main chain.  A standalone transaction
	// will be mined into the next block at best, so it's height is at least
	// one more than the current height.
	_, curHeight, err := mp.cfg.NewestSha()
	if err != nil {
		// This is an unexpected error so don't turn it into a rule
		// error.
		return nil, err
	}
	nextBlockHeight := curHeight + 1

	// Don't allow non-standard transactions if the network parameters
	// forbid their relaying.
	if !activeNetParams.RelayNonStdTxs {
		err := checkTransactionStandard(tx, nextBlockHeight,
			mp.cfg.TimeSource, mp.cfg.MinRelayTxFee)
		if err != nil {
			// Attempt to extract a reject code from the error so
			// it can be retained.  When not possible, fall back to
			// a non standard error.
			rejectCode, found := extractRejectCode(err)
			if !found {
				rejectCode = wire.RejectNonstandard
			}
			str := fmt.Sprintf("transaction %v is not standard: %v",
				txHash, err)
			return nil, txRuleError(rejectCode, str)
		}
	}

	// The transaction may not use any of the same outputs as other
	// transactions already in the pool as that would ultimately result in a
	// double spend.  This check is intended to be quick and therefore only
	// detects double spends within the transaction pool itself.  The
	// transaction could still be double spending coins from the main chain
	// at this point.  There is a more in-depth check that happens later
	// after fetching the referenced transaction inputs from the main chain
	// which examines the actual spend data and prevents double spends.
	err = mp.checkPoolDoubleSpend(tx)
	if err != nil {
		return nil, err
	}

	// Fetch all of the transactions referenced by the inputs to this
	// transaction.  This function also attempts to fetch the transaction
	// itself to be used for detecting a duplicate transaction without
	// needing to do a separate lookup.
	txStore, err := mp.fetchInputTransactions(tx, false)
	if err != nil {
		if cerr, ok := err.(blockchain.RuleError); ok {
			return nil, chainRuleError(cerr)
		}
		return nil, err
	}

	// Don't allow the transaction if it exists in the main chain and is not
//.........這裏部分代碼省略.........