Golang Block.MsgBlock方法代码示例

// getPrevNodeFromBlock returns a block node for the block previous to the
// passed block (the passed block's parent).  When it is already in the memory
// block chain, it simply returns it.  Otherwise, it loads the previous block
// from the block database, creates a new block node from it, and returns it.
// The returned node will be nil if the genesis block is passed.
func (b *BlockChain) getPrevNodeFromBlock(block *btcutil.Block) (*blockNode, error) {
	// Genesis block.
	prevHash := &block.MsgBlock().Header.PrevBlock
	if prevHash.IsEqual(zeroHash) {
		return nil, nil
	}

	// Latest checkpoint block
	if prevHash.IsEqual(b.chainParams.Checkpoints[len(b.chainParams.Checkpoints)-1].Hash) {
		return nil, nil
	}

	// Return the existing previous block node if it's already there.
	if bn, ok := b.index[*prevHash]; ok {
		return bn, nil
	}

	// Dynamically load the previous block from the block database, create
	// a new block node for it, and update the memory chain accordingly.
	prevBlockNode, err := b.loadBlockNode(prevHash)
	if err != nil {
		return nil, err
	}
	return prevBlockNode, nil
}

// connectBlock handles connecting the passed node/block to the end of the main
// (best) chain.
func (b *BlockChain) connectBlock(node *blockNode, block *btcutil.Block) error {
	// Make sure it's extending the end of the best chain.
	prevHash := &block.MsgBlock().Header.PrevBlock
	if b.bestChain != nil && !prevHash.IsEqual(b.bestChain.hash) {
		return fmt.Errorf("connectBlock must be called with a block " +
			"that extends the main chain")
	}

	// Insert the block into the database which houses the main chain.
	_, err := b.db.InsertBlock(block)
	if err != nil {
		return err
	}

	// Add the new node to the memory main chain indices for faster
	// lookups.
	node.inMainChain = true
	b.index[*node.hash] = node
	b.depNodes[*prevHash] = append(b.depNodes[*prevHash], node)

	// This node is now the end of the best chain.
	b.bestChain = node

	// Notify the caller that the block was connected to the main chain.
	// The caller would typically want to react with actions such as
	// updating wallets.
	b.sendNotification(NTBlockConnected, block)

	return nil
}

// 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
}

// 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.Sha()) {
		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.Sha()))
	}

	// 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)
}

// 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.
//
//
// The flags modify the behavior of this function as follows:
//  - BFNoPoWCheck: The check to ensure the block hash is less than the target
//    difficulty is not performed.
func checkProofOfWork(block *btcutil.Block, powLimit *big.Int, flags BehaviorFlags) error {
	// The target difficulty must be larger than zero.
	target := CompactToBig(block.MsgBlock().Header.Bits)
	if target.Sign() <= 0 {
		str := fmt.Sprintf("block target difficulty of %064x is too low",
			target)
		return ruleError(ErrUnexpectedDifficulty, str)
	}

	// The target difficulty must be less than the maximum allowed.
	if target.Cmp(powLimit) > 0 {
		str := fmt.Sprintf("block target difficulty of %064x is "+
			"higher than max of %064x", target, powLimit)
		return ruleError(ErrUnexpectedDifficulty, str)
	}

	// The block hash must be less than the claimed target unless the flag
	// to avoid proof of work checks is set.
	if flags&BFNoPoWCheck != BFNoPoWCheck {
		// The block hash must be less than the claimed target.
		blockHash, err := block.Sha()
		if err != nil {
			return err
		}
		hashNum := ShaHashToBig(blockHash)
		if hashNum.Cmp(target) > 0 {
			str := fmt.Sprintf("block hash of %064x is higher than "+
				"expected max of %064x", hashNum, target)
			return ruleError(ErrHighHash, str)
		}
	}

	return nil
}

// createBlock creates a new block building from the previous block.
func createBlock(prevBlock *btcutil.Block, inclusionTxs []*btcutil.Tx,
	blockVersion int32, blockTime time.Time,
	miningAddr btcutil.Address, net *chaincfg.Params) (*btcutil.Block, error) {

	prevHash := prevBlock.Hash()
	blockHeight := prevBlock.Height() + 1

	// 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 = prevBlock.MsgBlock().Header.Timestamp.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)
	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
}

// 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 *btcutil.Block
		blksha, buf, err := db.getBlkByHeight(height)
		if err != nil {
			return err
		}
		blk, err = btcutil.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(height))
	}

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

	return nil
}

// 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 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)
}

// 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
	}

	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.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) &&
			b.isMajorityVersion(serializedHeightVersion, prevNode,
				b.chainParams.BlockEnforceNumRequired) {

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

	return 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)
}

// 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
	}

	// Get the block sha.  It is safe to ignore the error here since any
	// errors would've been caught prior to calling this function.
	blockSha, _ := block.Sha()

	// 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[*blockSha] = 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
}

// 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 *btcutil.Block, filter *Filter) (*wire.MsgMerkleBlock, []uint32) {
	numTx := uint32(len(block.Transactions()))
	mBlock := merkleBlock{
		numTx:       numTx,
		allHashes:   make([]*chainhash.Hash, 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.Hash())
	}

	// 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: mBlock.numTx,
		Hashes:       make([]*chainhash.Hash, 0, len(mBlock.finalHashes)),
		Flags:        make([]byte, (len(mBlock.bits)+7)/8),
	}
	for _, hash := range mBlock.finalHashes {
		msgMerkleBlock.AddTxHash(hash)
	}
	for i := uint32(0); i < uint32(len(mBlock.bits)); i++ {
		msgMerkleBlock.Flags[i/8] |= mBlock.bits[i] << (i % 8)
	}
	return &msgMerkleBlock, matchedIndices
}

// 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.
	blockSha, _ := block.Sha()
	coinbaseTx := block.MsgBlock().Transactions[0].TxOut[0]
	minrLog.Infof("Block submitted via CPU miner accepted (hash %s, "+
		"amount %v)", blockSha, 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.Sha()))
	}

	// 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.Sha(), block.Height())
}