Golang btcutil.Block类代码示例

// 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 *btcutil.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 using multiple goroutines.
func checkBlockScripts(block *btcutil.Block, utxoView *UtxoViewpoint, 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(utxoView, scriptFlags, sigCache)
	return validator.Validate(txValItems)
}

// indexBlock extract all of the standard addresses from all of the transactions
// in the passed block and maps each of them to the assocaited transaction using
// the passed map.
func (idx *AddrIndex) indexBlock(data writeIndexData, block *btcutil.Block, view *blockchain.UtxoViewpoint) {
	for txIdx, tx := range block.Transactions() {
		// Coinbases do not reference any inputs.  Since the block is
		// required to have already gone through full validation, it has
		// already been proven on the first transaction in the block is
		// a coinbase.
		if txIdx != 0 {
			for _, txIn := range tx.MsgTx().TxIn {
				// The view should always have the input since
				// the index contract requires it, however, be
				// safe and simply ignore any missing entries.
				origin := &txIn.PreviousOutPoint
				entry := view.LookupEntry(&origin.Hash)
				if entry == nil {
					continue
				}

				pkScript := entry.PkScriptByIndex(origin.Index)
				idx.indexPkScript(data, pkScript, txIdx)
			}
		}

		for _, txOut := range tx.MsgTx().TxOut {
			idx.indexPkScript(data, txOut.PkScript, txIdx)
		}
	}
}

// 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
}

// 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
}

// 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.
//
// This function MUST be called with the chain state lock held (for reads).
func (b *BlockChain) checkBIP0030(node *blockNode, block *btcutil.Block, view *UtxoViewpoint) error {
	// Fetch utxo details for all of the transactions in this block.
	// Typically, there will not be any utxos for any of the transactions.
	fetchSet := make(map[chainhash.Hash]struct{})
	for _, tx := range block.Transactions() {
		fetchSet[*tx.Hash()] = struct{}{}
	}
	err := view.fetchUtxos(b.db, fetchSet)
	if err != nil {
		return err
	}

	// Duplicate transactions are only allowed if the previous transaction
	// is fully spent.
	for _, tx := range block.Transactions() {
		txEntry := view.LookupEntry(tx.Hash())
		if txEntry != nil && !txEntry.IsFullySpent() {
			str := fmt.Sprintf("tried to overwrite transaction %v "+
				"at block height %d that is not fully spent",
				tx.Hash(), txEntry.blockHeight)
			return ruleError(ErrOverwriteTx, str)
		}
	}

	return nil
}

// ConnectBlock is invoked by the index manager when a new block has been
// connected to the main chain.  This indexer adds a mapping for each address
// the transactions in the block involve.
//
// This is part of the Indexer interface.
func (idx *AddrIndex) ConnectBlock(dbTx database.Tx, block *btcutil.Block, view *blockchain.UtxoViewpoint) error {
	// The offset and length of the transactions within the serialized
	// block.
	txLocs, err := block.TxLoc()
	if err != nil {
		return err
	}

	// Get the internal block ID associated with the block.
	blockID, err := dbFetchBlockIDByHash(dbTx, block.Hash())
	if err != nil {
		return err
	}

	// Build all of the address to transaction mappings in a local map.
	addrsToTxns := make(writeIndexData)
	idx.indexBlock(addrsToTxns, block, view)

	// Add all of the index entries for each address.
	addrIdxBucket := dbTx.Metadata().Bucket(addrIndexKey)
	for addrKey, txIdxs := range addrsToTxns {
		for _, txIdx := range txIdxs {
			err := dbPutAddrIndexEntry(addrIdxBucket, addrKey,
				blockID, txLocs[txIdx])
			if err != nil {
				return err
			}
		}
	}

	return nil
}

// makeUtxoView creates a mock unspent transaction output view by using the
// transaction index in order to look up all inputs referenced by the
// transactions in the block.  This is sometimes needed when catching indexes up
// because many of the txouts could actually already be spent however the
// associated scripts are still required to index them.
func makeUtxoView(dbTx database.Tx, block *btcutil.Block) (*blockchain.UtxoViewpoint, error) {
	view := blockchain.NewUtxoViewpoint()
	for txIdx, tx := range block.Transactions() {
		// Coinbases do not reference any inputs.  Since the block is
		// required to have already gone through full validation, it has
		// already been proven on the first transaction in the block is
		// a coinbase.
		if txIdx == 0 {
			continue
		}

		// Use the transaction index to load all of the referenced
		// inputs and add their outputs to the view.
		for _, txIn := range tx.MsgTx().TxIn {
			originOut := &txIn.PreviousOutPoint
			originTx, err := dbFetchTx(dbTx, &originOut.Hash)
			if err != nil {
				return nil, err
			}

			view.AddTxOuts(btcutil.NewTx(originTx), 0)
		}
	}

	return view, 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
}

// 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 *btcutil.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
}

// dbRemoveTxIndexEntries uses an existing database transaction to remove the
// latest transaction entry for every transaction in the passed block.
func dbRemoveTxIndexEntries(dbTx database.Tx, block *btcutil.Block) error {
	for _, tx := range block.Transactions() {
		err := dbRemoveTxIndexEntry(dbTx, tx.Hash())
		if err != nil {
			return err
		}
	}

	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 *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
}

// SubmitBlockAsync returns an instance of a type that can be used to get the
// result of the RPC at some future time by invoking the Receive function on the
// returned instance.
//
// See SubmitBlock for the blocking version and more details.
func (c *Client) SubmitBlockAsync(block *btcutil.Block, options *btcjson.SubmitBlockOptions) FutureSubmitBlockResult {
	blockHex := ""
	if block != nil {
		blockBytes, err := block.Bytes()
		if err != nil {
			return newFutureError(err)
		}

		blockHex = hex.EncodeToString(blockBytes)
	}

	cmd := btcjson.NewSubmitBlockCmd(blockHex, options)
	return c.sendCmd(cmd)
}

// 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)
}

// DisconnectBlock is invoked by the index manager when a block has been
// disconnected from the main chain.  This indexer removes the
// hash-to-transaction mapping for every transaction in the block.
//
// This is part of the Indexer interface.
func (idx *TxIndex) DisconnectBlock(dbTx database.Tx, block *btcutil.Block, view *blockchain.UtxoViewpoint) error {
	// Remove all of the transactions in the block from the index.
	if err := dbRemoveTxIndexEntries(dbTx, block); err != nil {
		return err
	}

	// Remove the block ID index entry for the block being disconnected and
	// decrement the current internal block ID to account for it.
	if err := dbRemoveBlockIDIndexEntry(dbTx, block.Hash()); err != nil {
		return err
	}
	idx.curBlockID--
	return nil
}