Golang Block.Sha方法代碼示例

// 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 NOT safe for concurrent access.
func (b *BlockChain) CheckConnectBlock(block *btcutil.Block) error {
	prevNode := b.bestChain
	newNode := newBlockNode(&block.MsgBlock().Header, block.Sha(),
		block.Height())
	if prevNode != nil {
		newNode.parent = prevNode
		newNode.workSum.Add(prevNode.workSum, newNode.workSum)
	}

	return b.checkConnectBlock(newNode, block)
}

// addOrphanBlock adds the passed block (which is already determined to be
// an orphan prior calling this function) to the orphan pool.  It lazily cleans
// up any expired blocks so a separate cleanup poller doesn't need to be run.
// It also imposes a maximum limit on the number of outstanding orphan
// blocks and will remove the oldest received orphan block if the limit is
// exceeded.
func (b *BlockChain) addOrphanBlock(block *btcutil.Block) {
	// Remove expired orphan blocks.
	for _, oBlock := range b.orphans {
		if time.Now().After(oBlock.expiration) {
			b.removeOrphanBlock(oBlock)
			continue
		}

		// Update the oldest orphan block pointer so it can be discarded
		// in case the orphan pool fills up.
		if b.oldestOrphan == nil || oBlock.expiration.Before(b.oldestOrphan.expiration) {
			b.oldestOrphan = oBlock
		}
	}

	// Limit orphan blocks to prevent memory exhaustion.
	if len(b.orphans)+1 > maxOrphanBlocks {
		// Remove the oldest orphan to make room for the new one.
		b.removeOrphanBlock(b.oldestOrphan)
		b.oldestOrphan = nil
	}

	// Protect concurrent access.  This is intentionally done here instead
	// of near the top since removeOrphanBlock does its own locking and
	// the range iterator is not invalidated by removing map entries.
	b.orphanLock.Lock()
	defer b.orphanLock.Unlock()

	// Insert the block into the orphan map with an expiration time
	// 1 hour from now.
	expiration := time.Now().Add(time.Hour)
	oBlock := &orphanBlock{
		block:      block,
		expiration: expiration,
	}
	b.orphans[*block.Sha()] = oBlock

	// Add to previous hash lookup index for faster dependency lookups.
	prevHash := &block.MsgBlock().Header.PrevBlock
	b.prevOrphans[*prevHash] = append(b.prevOrphans[*prevHash], oBlock)

	return
}

// 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.
	latestHash, _ := m.server.blockManager.chainState.Best()
	msgBlock := block.MsgBlock()
	if !msgBlock.Header.PrevBlock.IsEqual(latestHash) {
		minrLog.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.server.blockManager.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 {
			minrLog.Errorf("Unexpected error while processing "+
				"block submitted via CPU miner: %v", err)
			return false
		}

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

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

// maybeAcceptBlock potentially accepts a block into the memory block 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.
func (b *BlockChain) maybeAcceptBlock(block *btcutil.Block, flags BehaviorFlags) 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 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 err
	}

	// Prune block nodes which are no longer needed before creating
	// a new node.
	if !dryRun {
		err = b.pruneBlockNodes()
		if err != nil {
			return 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.Sha(), 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.
	err = b.connectBestChain(newNode, block, flags)
	if err != nil {
		return 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.sendNotification(NTBlockAccepted, block)
	}

	return 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 *btcutil.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
}

// connectBestChain handles connecting the passed block to the chain while
// respecting proper chain selection according to the chain with the most
// proof of work.  In the typical case, the new block simply extends the main
// chain.  However, it may also be extending (or creating) a side chain (fork)
// which may or may not end up becoming the main chain depending on which fork
// cumulatively has the most proof of work.
//
// The flags modify the behavior of this function as follows:
//  - BFFastAdd: Avoids the call to checkConnectBlock which does several
//    expensive transaction validation operations.
//  - BFDryRun: Prevents the block from being connected and avoids modifying the
//    state of the memory chain index.  Also, any log messages related to
//    modifying the state are avoided.
func (b *BlockChain) connectBestChain(node *blockNode, block *btcutil.Block, flags BehaviorFlags) error {
	fastAdd := flags&BFFastAdd == BFFastAdd
	dryRun := flags&BFDryRun == BFDryRun

	// We haven't selected a best chain yet or we are extending the main
	// (best) chain with a new block.  This is the most common case.
	if b.bestChain == nil || node.parent.hash.IsEqual(b.bestChain.hash) {
		// Perform several checks to verify the block can be connected
		// to the main chain (including whatever reorganization might
		// be necessary to get this node to the main chain) without
		// violating any rules and without actually connecting the
		// block.
		if !fastAdd {
			err := b.checkConnectBlock(node, block)
			if err != nil {
				return err
			}
		}

		// Don't connect the block if performing a dry run.
		if dryRun {
			return nil
		}

		// Connect the block to the main chain.
		err := b.connectBlock(node, block)
		if err != nil {
			return err
		}

		// Connect the parent node to this node.
		if node.parent != nil {
			node.parent.children = append(node.parent.children, node)
		}

		return nil
	}
	if fastAdd {
		log.Warnf("fastAdd set in the side chain case? %v\n",
			block.Sha())
	}

	// We're extending (or creating) a side chain which may or may not
	// become the main chain, but in either case we need the block stored
	// for future processing, so add the block to the side chain holding
	// cache.
	if !dryRun {
		log.Debugf("Adding block %v to side chain cache", node.hash)
	}
	b.blockCache[*node.hash] = block
	b.index[*node.hash] = node

	// Connect the parent node to this node.
	node.inMainChain = false
	node.parent.children = append(node.parent.children, node)

	// Remove the block from the side chain cache and disconnect it from the
	// parent node when the function returns when running in dry run mode.
	if dryRun {
		defer func() {
			children := node.parent.children
			children = removeChildNode(children, node)
			node.parent.children = children

			delete(b.index, *node.hash)
			delete(b.blockCache, *node.hash)
		}()
	}

	// We're extending (or creating) a side chain, but the cumulative
	// work for this new side chain is not enough to make it the new chain.
	if node.workSum.Cmp(b.bestChain.workSum) <= 0 {
		// Skip Logging info when the dry run flag is set.
		if dryRun {
			return nil
		}

		// Find the fork point.
		fork := node
		for ; fork.parent != nil; fork = fork.parent {
			if fork.inMainChain {
				break
			}
		}

		// Log information about how the block is forking the chain.
		if fork.hash.IsEqual(node.parent.hash) {
//.........這裏部分代碼省略.........

// 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.
//
// It returns a bool which indicates whether or not the block is an orphan and
// any errors that occurred during processing.  The returned bool is only valid
// when the error is nil.
func (b *BlockChain) ProcessBlock(block *btcutil.Block, timeSource MedianTimeSource, flags BehaviorFlags) (bool, error) {
	fastAdd := flags&BFFastAdd == BFFastAdd
	dryRun := flags&BFDryRun == BFDryRun

	blockHash := block.Sha()
	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, err
	}
	if exists {
		str := fmt.Sprintf("already have block %v", blockHash)
		return 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, ruleError(ErrDuplicateBlock, str)
	}

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

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

			return true, nil
		}
	}

	// The block has passed all context independent checks and appears sane
	// enough to potentially accept it into the block chain.
	err = b.maybeAcceptBlock(block, flags)
	if err != nil {
//.........這裏部分代碼省略.........

// 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.
func (db *LevelDb) InsertBlock(block *btcutil.Block) (height int32, rerr error) {
	db.dbLock.Lock()
	defer db.dbLock.Unlock()
	defer func() {
		if rerr == nil {
			rerr = db.processBatches()
		} else {
			db.lBatch().Reset()
		}
	}()

	blocksha := block.Sha()
	mblock := block.MsgBlock()
	rawMsg, err := block.Bytes()
	if err != nil {
		log.Warnf("Failed to obtain raw block sha %v", blocksha)
		return 0, err
	}
	txloc, err := block.TxLoc()
	if err != nil {
		log.Warnf("Failed to obtain raw block sha %v", blocksha)
		return 0, err
	}

	// Insert block into database
	newheight, err := db.insertBlockData(blocksha, &mblock.Header.PrevBlock,
		rawMsg)
	if err != nil {
		log.Warnf("Failed to insert block %v %v %v", blocksha,
			&mblock.Header.PrevBlock, err)
		return 0, err
	}

	// At least two blocks in the long past were generated by faulty
	// miners, the sha of the transaction exists in a previous block,
	// detect this condition and 'accept' the block.
	for txidx, tx := range mblock.Transactions {
		txsha, err := block.TxSha(txidx)
		if err != nil {
			log.Warnf("failed to compute tx name block %v idx %v err %v", blocksha, txidx, err)
			return 0, err
		}
		spentbuflen := (len(tx.TxOut) + 7) / 8
		spentbuf := make([]byte, spentbuflen, spentbuflen)
		if len(tx.TxOut)%8 != 0 {
			for i := uint(len(tx.TxOut) % 8); i < 8; i++ {
				spentbuf[spentbuflen-1] |= (byte(1) << i)
			}
		}

		err = db.insertTx(txsha, newheight, txloc[txidx].TxStart, txloc[txidx].TxLen, spentbuf)
		if err != nil {
			log.Warnf("block %v idx %v failed to insert tx %v %v err %v", blocksha, newheight, &txsha, txidx, err)
			return 0, err
		}

		// Some old blocks contain duplicate transactions
		// Attempt to cleanly bypass this problem by marking the
		// first as fully spent.
		// http://blockexplorer.com/b/91812 dup in 91842
		// http://blockexplorer.com/b/91722 dup in 91880
		if newheight == 91812 {
			dupsha, err := wire.NewShaHashFromStr("d5d27987d2a3dfc724e359870c6644b40e497bdc0589a033220fe15429d88599")
			if err != nil {
				panic("invalid sha string in source")
			}
			if txsha.IsEqual(dupsha) {
				// marking TxOut[0] as spent
				po := wire.NewOutPoint(dupsha, 0)
				txI := wire.NewTxIn(po, []byte("garbage"))

				var spendtx wire.MsgTx
				spendtx.AddTxIn(txI)
				err = db.doSpend(&spendtx)
				if err != nil {
					log.Warnf("block %v idx %v failed to spend tx %v %v err %v", blocksha, newheight, &txsha, txidx, err)
				}
			}
		}
		if newheight == 91722 {
			dupsha, err := wire.NewShaHashFromStr("e3bf3d07d4b0375638d5f1db5255fe07ba2c4cb067cd81b84ee974b6585fb468")
			if err != nil {
				panic("invalid sha string in source")
			}
			if txsha.IsEqual(dupsha) {
				// marking TxOut[0] as spent
				po := wire.NewOutPoint(dupsha, 0)
				txI := wire.NewTxIn(po, []byte("garbage"))

				var spendtx wire.MsgTx
				spendtx.AddTxIn(txI)
				err = db.doSpend(&spendtx)
				if err != nil {
					log.Warnf("block %v idx %v failed to spend tx %v %v err %v", blocksha, newheight, &txsha, txidx, err)
				}
			}
//.........這裏部分代碼省略.........

// 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 *btcutil.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.
//.........這裏部分代碼省略.........