Exemplo n.º 1
0
// NewBlockTemplate returns a new block template that is ready to be solved
// using the transactions from the passed transaction source pool and a coinbase
// that either pays to the passed address if it is not nil, or a coinbase that
// is redeemable by anyone if the passed address is nil.  The nil address
// functionality is useful since there are cases such as the getblocktemplate
// RPC where external mining software is responsible for creating their own
// coinbase which will replace the one generated for the block template.  Thus
// the need to have configured address can be avoided.
//
// The transactions selected and included are prioritized according to several
// factors.  First, each transaction has a priority calculated based on its
// value, age of inputs, and size.  Transactions which consist of larger
// amounts, older inputs, and small sizes have the highest priority.  Second, a
// fee per kilobyte is calculated for each transaction.  Transactions with a
// higher fee per kilobyte are preferred.  Finally, the block generation related
// policy settings are all taken into account.
//
// Transactions which only spend outputs from other transactions already in the
// block chain are immediately added to a priority queue which either
// prioritizes based on the priority (then fee per kilobyte) or the fee per
// kilobyte (then priority) depending on whether or not the BlockPrioritySize
// policy setting allots space for high-priority transactions.  Transactions
// which spend outputs from other transactions in the source pool are added to a
// dependency map so they can be added to the priority queue once the
// transactions they depend on have been included.
//
// Once the high-priority area (if configured) has been filled with
// transactions, or the priority falls below what is considered high-priority,
// the priority queue is updated to prioritize by fees per kilobyte (then
// priority).
//
// When the fees per kilobyte drop below the TxMinFreeFee policy setting, the
// transaction will be skipped unless the BlockMinSize policy setting is
// nonzero, in which case the block will be filled with the low-fee/free
// transactions until the block size reaches that minimum size.
//
// Any transactions which would cause the block to exceed the BlockMaxSize
// policy setting, exceed the maximum allowed signature operations per block, or
// otherwise cause the block to be invalid are skipped.
//
// Given the above, a block generated by this function is of the following form:
//
//   -----------------------------------  --  --
//  |      Coinbase Transaction         |   |   |
//  |-----------------------------------|   |   |
//  |                                   |   |   | ----- policy.BlockPrioritySize
//  |   High-priority Transactions      |   |   |
//  |                                   |   |   |
//  |-----------------------------------|   | --
//  |                                   |   |
//  |                                   |   |
//  |                                   |   |--- policy.BlockMaxSize
//  |  Transactions prioritized by fee  |   |
//  |  until <= policy.TxMinFreeFee     |   |
//  |                                   |   |
//  |                                   |   |
//  |                                   |   |
//  |-----------------------------------|   |
//  |  Low-fee/Non high-priority (free) |   |
//  |  transactions (while block size   |   |
//  |  <= policy.BlockMinSize)          |   |
//   -----------------------------------  --
func (g *BlkTmplGenerator) NewBlockTemplate(payToAddress btcutil.Address) (*BlockTemplate, error) {
	// Extend the most recently known best block.
	best := g.chain.BestSnapshot()
	prevHash := best.Hash
	nextBlockHeight := best.Height + 1

	// Create a standard coinbase transaction paying to the provided
	// address.  NOTE: The coinbase value will be updated to include the
	// fees from the selected transactions later after they have actually
	// been selected.  It is created here to detect any errors early
	// before potentially doing a lot of work below.  The extra nonce helps
	// ensure the transaction is not a duplicate transaction (paying the
	// same value to the same public key address would otherwise be an
	// identical transaction for block version 1).
	extraNonce := uint64(0)
	coinbaseScript, err := standardCoinbaseScript(nextBlockHeight, extraNonce)
	if err != nil {
		return nil, err
	}
	// TODO(roasbeef): add witnesss commitment output
	coinbaseTx, err := createCoinbaseTx(g.chainParams, coinbaseScript,
		nextBlockHeight, payToAddress)
	if err != nil {
		return nil, err
	}
	coinbaseSigOpCost := int64(blockchain.CountSigOps(coinbaseTx)) * blockchain.WitnessScaleFactor

	// Get the current source transactions and create a priority queue to
	// hold the transactions which are ready for inclusion into a block
	// along with some priority related and fee metadata.  Reserve the same
	// number of items that are available for the priority queue.  Also,
	// choose the initial sort order for the priority queue based on whether
	// or not there is an area allocated for high-priority transactions.
	sourceTxns := g.txSource.MiningDescs()
	sortedByFee := g.policy.BlockPrioritySize == 0
	priorityQueue := newTxPriorityQueue(len(sourceTxns), sortedByFee)

	// Create a slice to hold the transactions to be included in the
	// generated block with reserved space.  Also create a utxo view to
	// house all of the input transactions so multiple lookups can be
	// avoided.
	blockTxns := make([]*btcutil.Tx, 0, len(sourceTxns))
	blockTxns = append(blockTxns, coinbaseTx)
	blockUtxos := blockchain.NewUtxoViewpoint()

	// dependers is used to track transactions which depend on another
	// transaction in the source pool.  This, in conjunction with the
	// dependsOn map kept with each dependent transaction helps quickly
	// determine which dependent transactions are now eligible for inclusion
	// in the block once each transaction has been included.
	dependers := make(map[chainhash.Hash]map[chainhash.Hash]*txPrioItem)

	// Create slices to hold the fees and number of signature operations
	// for each of the selected transactions and add an entry for the
	// coinbase.  This allows the code below to simply append details about
	// a transaction as it is selected for inclusion in the final block.
	// However, since the total fees aren't known yet, use a dummy value for
	// the coinbase fee which will be updated later.
	txFees := make([]int64, 0, len(sourceTxns))
	txSigOpCosts := make([]int64, 0, len(sourceTxns))
	txFees = append(txFees, -1) // Updated once known
	txSigOpCosts = append(txSigOpCosts, coinbaseSigOpCost)

	log.Debugf("Considering %d transactions for inclusion to new block",
		len(sourceTxns))

mempoolLoop:
	for _, txDesc := range sourceTxns {
		// A block can't have more than one coinbase or contain
		// non-finalized transactions.
		tx := txDesc.Tx
		if blockchain.IsCoinBase(tx) {
			log.Tracef("Skipping coinbase tx %s", tx.Hash())
			continue
		}
		if !blockchain.IsFinalizedTransaction(tx, nextBlockHeight,
			g.timeSource.AdjustedTime()) {

			log.Tracef("Skipping non-finalized tx %s", tx.Hash())
			continue
		}

		// Fetch all of the utxos referenced by the this transaction.
		// NOTE: This intentionally does not fetch inputs from the
		// mempool since a transaction which depends on other
		// transactions in the mempool must come after those
		// dependencies in the final generated block.
		utxos, err := g.chain.FetchUtxoView(tx)
		if err != nil {
			log.Warnf("Unable to fetch utxo view for tx %s: %v",
				tx.Hash(), err)
			continue
		}

		// Setup dependencies for any transactions which reference
		// other transactions in the mempool so they can be properly
		// ordered below.
		prioItem := &txPrioItem{tx: tx}
		for _, txIn := range tx.MsgTx().TxIn {
			originHash := &txIn.PreviousOutPoint.Hash
			originIndex := txIn.PreviousOutPoint.Index
			utxoEntry := utxos.LookupEntry(originHash)
			if utxoEntry == nil || utxoEntry.IsOutputSpent(originIndex) {
				if !g.txSource.HaveTransaction(originHash) {
					log.Tracef("Skipping tx %s because it "+
						"references unspent output %s "+
						"which is not available",
						tx.Hash(), txIn.PreviousOutPoint)
					continue mempoolLoop
				}

				// The transaction is referencing another
				// transaction in the source pool, so setup an
				// ordering dependency.
				deps, exists := dependers[*originHash]
				if !exists {
					deps = make(map[chainhash.Hash]*txPrioItem)
					dependers[*originHash] = deps
				}
				deps[*prioItem.tx.Hash()] = prioItem
				if prioItem.dependsOn == nil {
					prioItem.dependsOn = make(
						map[chainhash.Hash]struct{})
				}
				prioItem.dependsOn[*originHash] = struct{}{}

				// Skip the check below. We already know the
				// referenced transaction is available.
				continue
			}
		}

		// Calculate the final transaction priority using the input
		// value age sum as well as the adjusted transaction size.  The
		// formula is: sum(inputValue * inputAge) / adjustedTxSize
		prioItem.priority = CalcPriority(tx.MsgTx(), utxos,
			nextBlockHeight)

		// Calculate the fee in Satoshi/kB.
		// TODO(roasbeef): cost accounting by weight
		prioItem.feePerKB = txDesc.FeePerKB
		prioItem.fee = txDesc.Fee

		// Add the transaction to the priority queue to mark it ready
		// for inclusion in the block unless it has dependencies.
		if prioItem.dependsOn == nil {
			heap.Push(priorityQueue, prioItem)
		}

		// Merge the referenced outputs from the input transactions to
		// this transaction into the block utxo view.  This allows the
		// code below to avoid a second lookup.
		mergeUtxoView(blockUtxos, utxos)
	}

	log.Tracef("Priority queue len %d, dependers len %d",
		priorityQueue.Len(), len(dependers))

	// The starting block size is the size of the block header plus the max
	// possible transaction count size, plus the size of the coinbase
	// transaction.
	blockWeight := uint32((blockHeaderOverhead * blockchain.WitnessScaleFactor) +
		blockchain.GetTransactionWeight(coinbaseTx))
	blockSigOpCost := coinbaseSigOpCost
	totalFees := int64(0)

	// Query the version bits state to see if segwit has been activated, if
	// so then this means that we'll include any transactions with witness
	// data in the mempool, and also add the witness commitment as an
	// OP_RETURN output in the coinbase transaction.
	segwitState, err := g.chain.ThresholdState(chaincfg.DeploymentSegwit)
	if err != nil {
		return nil, err
	}
	segwitActive := segwitState == blockchain.ThresholdActive

	witnessIncluded := false

	// Choose which transactions make it into the block.
	for priorityQueue.Len() > 0 {
		// Grab the highest priority (or highest fee per kilobyte
		// depending on the sort order) transaction.
		prioItem := heap.Pop(priorityQueue).(*txPrioItem)
		tx := prioItem.tx

		switch {
		// If segregated witness has not been activated yet, then we
		// shouldn't include any witness transactions in the block.
		case tx.MsgTx().HasWitness() && !segwitActive:
			continue

		// Otherwise, Keep track of if we've included a transaction
		// with witness data or not. If so, then we'll need to include
		// the witness commitment as the last output in the coinbase
		// transaction.
		case tx.MsgTx().HasWitness() && segwitActive:
			// If we're about to include a transaction bearing
			// witness data, then we'll also need to include a
			// witness commitment in the coinbase transaction.
			// Therefore, we account for the additional weight
			// within the block.
			if !witnessIncluded {
				// First we account for the additional witness
				// data in the witness nonce of the coinbaes
				// transaction: 32-bytes of zeroes.
				blockWeight += 2 + 32

				// Next we account for the additional flag and
				// marker bytes in the transaction
				// serialization.
				blockWeight += (1 + 1) * blockchain.WitnessScaleFactor

				// Finally we account for the weight of the
				// additional OP_RETURN output: 8-bytes (value)
				// + 1-byte (var-int) + 38-bytes (pkScript),
				// scaling up the weight as it's non-witness
				// data.
				blockWeight += (8 + 1 + 38) * blockchain.WitnessScaleFactor
			}

			witnessIncluded = true
		}

		// Grab any transactions which depend on this one.
		deps := dependers[*tx.Hash()]

		// Enforce maximum block size.  Also check for overflow.
		txWeight := uint32(blockchain.GetTransactionWeight(tx))
		blockPlusTxWeight := uint32(blockWeight + txWeight)
		if blockPlusTxWeight < blockWeight ||
			blockPlusTxWeight >= g.policy.BlockMaxWeight {

			log.Tracef("Skipping tx %s because it would exceed "+
				"the max block weight", tx.Hash())
			logSkippedDeps(tx, deps)
			continue
		}

		// Enforce maximum signature operation cost per block.  Also
		// check for overflow.
		sigOpCost, err := blockchain.GetSigOpCost(tx, false,
			blockUtxos, true, segwitActive)
		if err != nil {
			log.Tracef("Skipping tx %s due to error in "+
				"GetSigOpCost: %v", tx.Hash(), err)
			logSkippedDeps(tx, deps)
			continue
		}
		if blockSigOpCost+int64(sigOpCost) < blockSigOpCost ||
			blockSigOpCost+int64(sigOpCost) > blockchain.MaxBlockSigOpsCost {
			log.Tracef("Skipping tx %s because it would "+
				"exceed the maximum sigops per block", tx.Hash())
			logSkippedDeps(tx, deps)
			continue
		}

		// Skip free transactions once the block is larger than the
		// minimum block size.
		if sortedByFee &&
			prioItem.feePerKB < int64(g.policy.TxMinFreeFee) &&
			blockPlusTxWeight >= g.policy.BlockMinWeight {

			log.Tracef("Skipping tx %s with feePerKB %d "+
				"< TxMinFreeFee %d and block weight %d >= "+
				"minBlockWeight %d", tx.Hash(), prioItem.feePerKB,
				g.policy.TxMinFreeFee, blockPlusTxWeight,
				g.policy.BlockMinWeight)
			logSkippedDeps(tx, deps)
			continue
		}

		// Prioritize by fee per kilobyte once the block is larger than
		// the priority size or there are no more high-priority
		// transactions.
		if !sortedByFee && (blockPlusTxWeight >= g.policy.BlockPrioritySize ||
			prioItem.priority <= MinHighPriority) {

			log.Tracef("Switching to sort by fees per "+
				"kilobyte blockSize %d >= BlockPrioritySize "+
				"%d || priority %.2f <= minHighPriority %.2f",
				blockPlusTxWeight, g.policy.BlockPrioritySize,
				prioItem.priority, MinHighPriority)

			sortedByFee = true
			priorityQueue.SetLessFunc(txPQByFee)

			// Put the transaction back into the priority queue and
			// skip it so it is re-priortized by fees if it won't
			// fit into the high-priority section or the priority
			// is too low.  Otherwise this transaction will be the
			// final one in the high-priority section, so just fall
			// though to the code below so it is added now.
			if blockPlusTxWeight > g.policy.BlockPrioritySize ||
				prioItem.priority < MinHighPriority {

				heap.Push(priorityQueue, prioItem)
				continue
			}
		}

		// Ensure the transaction inputs pass all of the necessary
		// preconditions before allowing it to be added to the block.
		_, err = blockchain.CheckTransactionInputs(tx, nextBlockHeight,
			blockUtxos, g.chainParams)
		if err != nil {
			log.Tracef("Skipping tx %s due to error in "+
				"CheckTransactionInputs: %v", tx.Hash(), err)
			logSkippedDeps(tx, deps)
			continue
		}
		err = blockchain.ValidateTransactionScripts(tx, blockUtxos,
			txscript.StandardVerifyFlags, g.sigCache,
			g.hashCache)
		if err != nil {
			log.Tracef("Skipping tx %s due to error in "+
				"ValidateTransactionScripts: %v", tx.Hash(), err)
			logSkippedDeps(tx, deps)
			continue
		}

		// Spend the transaction inputs in the block utxo view and add
		// an entry for it to ensure any transactions which reference
		// this one have it available as an input and can ensure they
		// aren't double spending.
		spendTransaction(blockUtxos, tx, nextBlockHeight)

		// Add the transaction to the block, increment counters, and
		// save the fees and signature operation counts to the block
		// template.
		blockTxns = append(blockTxns, tx)
		blockWeight += txWeight
		blockSigOpCost += int64(sigOpCost)
		totalFees += prioItem.fee
		txFees = append(txFees, prioItem.fee)
		txSigOpCosts = append(txSigOpCosts, int64(sigOpCost))

		log.Tracef("Adding tx %s (priority %.2f, feePerKB %.2f)",
			prioItem.tx.Hash(), prioItem.priority, prioItem.feePerKB)

		// Add transactions which depend on this one (and also do not
		// have any other unsatisified dependencies) to the priority
		// queue.
		for _, item := range deps {
			// Add the transaction to the priority queue if there
			// are no more dependencies after this one.
			delete(item.dependsOn, *tx.Hash())
			if len(item.dependsOn) == 0 {
				heap.Push(priorityQueue, item)
			}
		}
	}

	// Now that the actual transactions have been selected, update the
	// block weight for the real transaction count and coinbase value with
	// the total fees accordingly.
	blockWeight -= wire.MaxVarIntPayload -
		(uint32(wire.VarIntSerializeSize(uint64(len(blockTxns)))) *
			blockchain.WitnessScaleFactor)
	coinbaseTx.MsgTx().TxOut[0].Value += totalFees
	txFees[0] = -totalFees

	// If segwit is active and we included transactions with witness data,
	// then we'll need to include a commitment to the witness data in an
	// OP_RETURN output within the coinbase transaction.
	if witnessIncluded {
		// The witness of the coinbase transaction MUST be exactly 32-bytes
		// of all zeroes.
		var witnessNonce [blockchain.CoinbaseWitnessDataLen]byte
		coinbaseTx.MsgTx().TxIn[0].Witness = wire.TxWitness{witnessNonce[:]}

		// Next, obtain the merkle root of a tree which consists of the
		// wtxid of all transactions in the block. The coinbase
		// transaction will have a special wtxid of all zeroes.
		witnessMerkleTree := blockchain.BuildMerkleTreeStore(blockTxns,
			true)
		witnessMerkleRoot := witnessMerkleTree[len(witnessMerkleTree)-1]

		// The preimage to the witness commitment is:
		// witnessRoot || coinbaseWitness
		var witnessPreimage [64]byte
		copy(witnessPreimage[:32], witnessMerkleRoot[:])
		copy(witnessPreimage[32:], witnessNonce[:])

		// The witness commitment itself is the double-sha256 of the
		// witness preimage generated above. With the commitment
		// generated, the witness script for the output is: OP_RETURN
		// OP_DATA_36 {0xaa21a9ed || witnessCommitment}. The leading
		// prefix is refered to as the "witness magic bytes".
		witnessCommitment := chainhash.DoubleHashB(witnessPreimage[:])
		witnessScript := append(blockchain.WitnessMagicBytes, witnessCommitment...)

		// Finally, create the OP_RETURN carrying witness commitment
		// output as an additional output within the coinbase.
		commitmentOutput := &wire.TxOut{
			Value:    0,
			PkScript: witnessScript,
		}
		coinbaseTx.MsgTx().TxOut = append(coinbaseTx.MsgTx().TxOut,
			commitmentOutput)
	}

	// Calculate the required difficulty for the block.  The timestamp
	// is potentially adjusted to ensure it comes after the median time of
	// the last several blocks per the chain consensus rules.
	ts := medianAdjustedTime(best, g.timeSource)
	reqDifficulty, err := g.chain.CalcNextRequiredDifficulty(ts)
	if err != nil {
		return nil, err
	}

	// Calculate the next expected block version based on the state of the
	// rule change deployments.
	nextBlockVersion, err := g.chain.CalcNextBlockVersion()
	if err != nil {
		return nil, err
	}

	// Create a new block ready to be solved.
	merkles := blockchain.BuildMerkleTreeStore(blockTxns, false)
	var msgBlock wire.MsgBlock
	msgBlock.Header = wire.BlockHeader{
		Version:    nextBlockVersion,
		PrevBlock:  *prevHash,
		MerkleRoot: *merkles[len(merkles)-1],
		Timestamp:  ts,
		Bits:       reqDifficulty,
	}
	for _, tx := range blockTxns {
		if err := msgBlock.AddTransaction(tx.MsgTx()); err != nil {
			return nil, err
		}
	}

	// Finally, perform a full check on the created block against the chain
	// consensus rules to ensure it properly connects to the current best
	// chain with no issues.
	block := btcutil.NewBlock(&msgBlock)
	block.SetHeight(nextBlockHeight)
	if err := g.chain.CheckConnectBlock(block); err != nil {
		return nil, err
	}

	log.Debugf("Created new block template (%d transactions, %d in "+
		"fees, %d signature operations cost, %d weight, target difficulty "+
		"%064x)", len(msgBlock.Transactions), totalFees, blockSigOpCost,
		blockWeight, blockchain.CompactToBig(msgBlock.Header.Bits))

	return &BlockTemplate{
		Block:           &msgBlock,
		Fees:            txFees,
		SigOpCosts:      txSigOpCosts,
		Height:          nextBlockHeight,
		ValidPayAddress: payToAddress != nil,
	}, nil
}
Exemplo n.º 2
0
// BlockRootOK checks for block self-consistency.
// If the block has no wintess txs, and no coinbase witness commitment,
// it only checks the tx merkle root.  If either a witness commitment or
// any witnesses are detected, it also checks that as well.
// Returns false if anything goes wrong, true if everything is fine.
func BlockOK(blk wire.MsgBlock) bool {
	var txids, wtxids []*wire.ShaHash // txids and wtxids
	// witMode true if any tx has a wintess OR coinbase has wit commit
	var witMode bool

	for _, tx := range blk.Transactions { // make slice of (w)/txids
		txid := tx.TxSha()
		wtxid := tx.WitnessHash()
		if !witMode && !txid.IsEqual(&wtxid) {
			witMode = true
		}
		txids = append(txids, &txid)
		wtxids = append(wtxids, &wtxid)
	}

	var commitBytes []byte
	// try to extract coinbase witness commitment (even if !witMode)
	cb := blk.Transactions[0]                 // get coinbase tx
	for i := len(cb.TxOut) - 1; i >= 0; i-- { // start at the last txout
		if bytes.HasPrefix(cb.TxOut[i].PkScript, WitMagicBytes) &&
			len(cb.TxOut[i].PkScript) > 37 {
			// 38 bytes or more, and starts with WitMagicBytes is a hit
			commitBytes = cb.TxOut[i].PkScript[6:38]
			witMode = true // it there is a wit commit it must be valid
		}
	}

	if witMode { // witmode, so check witness tree
		// first find ways witMode can be disqualified
		if len(commitBytes) != 32 {
			// witness in block but didn't find a wintess commitment; fail
			log.Printf("block %s has witness but no witcommit",
				blk.BlockSha().String())
			return false
		}
		if len(cb.TxIn) != 1 {
			log.Printf("block %s coinbase tx has %d txins (must be 1)",
				blk.BlockSha().String(), len(cb.TxIn))
			return false
		}
		if len(cb.TxIn[0].Witness) != 1 {
			log.Printf("block %s coinbase has %d witnesses (must be 1)",
				blk.BlockSha().String(), len(cb.TxIn[0].Witness))
			return false
		}

		if len(cb.TxIn[0].Witness[0]) != 32 {
			log.Printf("block %s coinbase has %d byte witness nonce (not 32)",
				blk.BlockSha().String(), len(cb.TxIn[0].Witness[0]))
			return false
		}
		// witness nonce is the cb's witness, subject to above constraints
		witNonce, err := wire.NewShaHash(cb.TxIn[0].Witness[0])
		if err != nil {
			log.Printf("Witness nonce error: %s", err.Error())
			return false // not sure why that'd happen but fail
		}

		var empty [32]byte
		wtxids[0].SetBytes(empty[:]) // coinbase wtxid is 0x00...00

		// witness root calculated from wtixds
		witRoot := calcRoot(wtxids)

		calcWitCommit := wire.DoubleSha256SH(
			append(witRoot.Bytes(), witNonce.Bytes()...))

		// witness root given in coinbase op_return
		givenWitCommit, err := wire.NewShaHash(commitBytes)
		if err != nil {
			log.Printf("Witness root error: %s", err.Error())
			return false // not sure why that'd happen but fail
		}
		// they should be the same.  If not, fail.
		if !calcWitCommit.IsEqual(givenWitCommit) {
			log.Printf("Block %s witRoot error: calc %s given %s",
				blk.BlockSha().String(),
				calcWitCommit.String(), givenWitCommit.String())
			return false
		}
	}

	// got through witMode check so that should be OK;
	// check regular txid merkleroot.  Which is, like, trivial.
	return blk.Header.MerkleRoot.IsEqual(calcRoot(txids))
}
Exemplo n.º 3
0
// CreateBlock creates a new block building from the previous block with a
// specified blockversion and timestamp. If the timestamp passed is zero (not
// initialized), then the timestamp of the previous block will be used plus 1
// second is used. Passing nil for the previous block results in a block that
// builds off of the genesis block for the specified chain.
func CreateBlock(prevBlock *btcutil.Block, inclusionTxs []*btcutil.Tx,
	blockVersion int32, blockTime time.Time,
	miningAddr btcutil.Address, net *chaincfg.Params) (*btcutil.Block, error) {

	var (
		prevHash      *chainhash.Hash
		blockHeight   int32
		prevBlockTime time.Time
	)

	// If the previous block isn't specified, then we'll construct a block
	// that builds off of the genesis block for the chain.
	if prevBlock == nil {
		prevHash = net.GenesisHash
		blockHeight = 1
		prevBlockTime = net.GenesisBlock.Header.Timestamp.Add(time.Minute)
	} else {
		prevHash = prevBlock.Hash()
		blockHeight = prevBlock.Height() + 1
		prevBlockTime = prevBlock.MsgBlock().Header.Timestamp
	}

	// 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 = prevBlockTime.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, false)
	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
}
Exemplo n.º 4
0
// IngestBlock is like IngestMerkleBlock but aralphic
// different enough that it's better to have 2 separate functions
func (s *SPVCon) IngestBlock(m *wire.MsgBlock) {
	var err error
	//	var buf bytes.Buffer
	//	m.SerializeWitness(&buf)
	//	fmt.Printf("block hex %x\n", buf.Bytes())
	//	for _, tx := range m.Transactions {
	//		fmt.Printf("wtxid: %s\n", tx.WTxSha())
	//		fmt.Printf(" txid: %s\n", tx.TxSha())
	//		fmt.Printf("%d %s", i, TxToString(tx))
	//	}
	ok := BlockOK(*m) // check block self-consistency
	if !ok {
		fmt.Printf("block %s not OK!!11\n", m.BlockSha().String())
		return
	}

	var hah HashAndHeight
	select { // select here so we don't block on an unrequested mblock
	case hah = <-s.blockQueue: // pop height off mblock queue
		break
	default:
		log.Printf("Unrequested full block")
		return
	}

	newBlockSha := m.Header.BlockSha()
	if !hah.blockhash.IsEqual(&newBlockSha) {
		log.Printf("full block out of order error")
		return
	}

	fPositive := 0 // local filter false positives
	reFilter := 10 // after that many false positives, regenerate filter.
	// 10?  Making it up.  False positives have disk i/o cost, and regenning
	// the filter also has costs.  With a large local filter, false positives
	// should be rare.

	// iterate through all txs in the block, looking for matches.
	// use a local bloom filter to ignore txs that don't affect us
	for _, tx := range m.Transactions {
		utilTx := btcutil.NewTx(tx)
		if s.TS.localFilter.MatchTxAndUpdate(utilTx) {
			hits, err := s.TS.Ingest(tx, hah.height)
			if err != nil {
				log.Printf("Incoming Tx error: %s\n", err.Error())
				return
			}
			if hits > 0 {
				// log.Printf("block %d tx %d %s ingested and matches %d utxo/adrs.",
				//	hah.height, i, tx.TxSha().String(), hits)
			} else {
				fPositive++ // matched filter but no hits
			}
		}
	}

	if fPositive > reFilter {
		fmt.Printf("%d filter false positives in this block\n", fPositive)
		err = s.TS.Refilter()
		if err != nil {
			log.Printf("Refilter error: %s\n", err.Error())
			return
		}
	}
	// write to db that we've sync'd to the height indicated in the
	// merkle block.  This isn't QUITE true since we haven't actually gotten
	// the txs yet but if there are problems with the txs we should backtrack.
	err = s.TS.SetDBSyncHeight(hah.height)
	if err != nil {
		log.Printf("full block sync error: %s\n", err.Error())
		return
	}

	fmt.Printf("ingested full block %s height %d OK\n",
		m.Header.BlockSha().String(), hah.height)

	if hah.final { // check sync end
		// don't set waitstate; instead, ask for headers again!
		// this way the only thing that triggers waitstate is asking for headers,
		// getting 0, calling AskForMerkBlocks(), and seeing you don't need any.
		// that way you are pretty sure you're synced up.
		err = s.AskForHeaders()
		if err != nil {
			log.Printf("Merkle block error: %s\n", err.Error())
			return
		}
	}
	return
}
Exemplo n.º 5
0
// TestFullBlocks ensures all tests generated by the fullblocktests package
// have the expected result when processed via ProcessBlock.
func TestFullBlocks(t *testing.T) {
	tests, err := fullblocktests.Generate(false)
	if err != nil {
		t.Fatalf("failed to generate tests: %v", err)
	}

	// Create a new database and chain instance to run tests against.
	chain, teardownFunc, err := chainSetup("fullblocktest",
		&chaincfg.RegressionNetParams)
	if err != nil {
		t.Errorf("Failed to setup chain instance: %v", err)
		return
	}
	defer teardownFunc()

	// testAcceptedBlock attempts to process the block in the provided test
	// instance and ensures that it was accepted according to the flags
	// specified in the test.
	testAcceptedBlock := func(item fullblocktests.AcceptedBlock) {
		blockHeight := item.Height
		block := btcutil.NewBlock(item.Block)
		block.SetHeight(blockHeight)
		t.Logf("Testing block %s (hash %s, height %d)",
			item.Name, block.Hash(), blockHeight)

		isMainChain, isOrphan, err := chain.ProcessBlock(block,
			blockchain.BFNone)
		if err != nil {
			t.Fatalf("block %q (hash %s, height %d) should "+
				"have been accepted: %v", item.Name,
				block.Hash(), blockHeight, err)
		}

		// Ensure the main chain and orphan flags match the values
		// specified in the test.
		if isMainChain != item.IsMainChain {
			t.Fatalf("block %q (hash %s, height %d) unexpected main "+
				"chain flag -- got %v, want %v", item.Name,
				block.Hash(), blockHeight, isMainChain,
				item.IsMainChain)
		}
		if isOrphan != item.IsOrphan {
			t.Fatalf("block %q (hash %s, height %d) unexpected "+
				"orphan flag -- got %v, want %v", item.Name,
				block.Hash(), blockHeight, isOrphan,
				item.IsOrphan)
		}
	}

	// testRejectedBlock attempts to process the block in the provided test
	// instance and ensures that it was rejected with the reject code
	// specified in the test.
	testRejectedBlock := func(item fullblocktests.RejectedBlock) {
		blockHeight := item.Height
		block := btcutil.NewBlock(item.Block)
		block.SetHeight(blockHeight)
		t.Logf("Testing block %s (hash %s, height %d)",
			item.Name, block.Hash(), blockHeight)

		_, _, err := chain.ProcessBlock(block, blockchain.BFNone)
		if err == nil {
			t.Fatalf("block %q (hash %s, height %d) should not "+
				"have been accepted", item.Name, block.Hash(),
				blockHeight)
		}

		// Ensure the error code is of the expected type and the reject
		// code matches the value specified in the test instance.
		rerr, ok := err.(blockchain.RuleError)
		if !ok {
			t.Fatalf("block %q (hash %s, height %d) returned "+
				"unexpected error type -- got %T, want "+
				"blockchain.RuleError", item.Name, block.Hash(),
				blockHeight, err)
		}
		if rerr.ErrorCode != item.RejectCode {
			t.Fatalf("block %q (hash %s, height %d) does not have "+
				"expected reject code -- got %v, want %v",
				item.Name, block.Hash(), blockHeight,
				rerr.ErrorCode, item.RejectCode)
		}
	}

	// testRejectedNonCanonicalBlock attempts to decode the block in the
	// provided test instance and ensures that it failed to decode with a
	// message error.
	testRejectedNonCanonicalBlock := func(item fullblocktests.RejectedNonCanonicalBlock) {
		headerLen := len(item.RawBlock)
		if headerLen > 80 {
			headerLen = 80
		}
		blockHash := chainhash.DoubleHashH(item.RawBlock[0:headerLen])
		blockHeight := item.Height
		t.Logf("Testing block %s (hash %s, height %d)", item.Name,
			blockHash, blockHeight)

		// Ensure there is an error due to deserializing the block.
		var msgBlock wire.MsgBlock
		err := msgBlock.BtcDecode(bytes.NewReader(item.RawBlock), 0, wire.BaseEncoding)
		if _, ok := err.(*wire.MessageError); !ok {
			t.Fatalf("block %q (hash %s, height %d) should have "+
				"failed to decode", item.Name, blockHash,
				blockHeight)
		}
	}

	// testOrphanOrRejectedBlock attempts to process the block in the
	// provided test instance and ensures that it was either accepted as an
	// orphan or rejected with a rule violation.
	testOrphanOrRejectedBlock := func(item fullblocktests.OrphanOrRejectedBlock) {
		blockHeight := item.Height
		block := btcutil.NewBlock(item.Block)
		block.SetHeight(blockHeight)
		t.Logf("Testing block %s (hash %s, height %d)",
			item.Name, block.Hash(), blockHeight)

		_, isOrphan, err := chain.ProcessBlock(block, blockchain.BFNone)
		if err != nil {
			// Ensure the error code is of the expected type.
			if _, ok := err.(blockchain.RuleError); !ok {
				t.Fatalf("block %q (hash %s, height %d) "+
					"returned unexpected error type -- "+
					"got %T, want blockchain.RuleError",
					item.Name, block.Hash(), blockHeight,
					err)
			}
		}

		if !isOrphan {
			t.Fatalf("block %q (hash %s, height %d) was accepted, "+
				"but is not considered an orphan", item.Name,
				block.Hash(), blockHeight)
		}
	}

	// testExpectedTip ensures the current tip of the blockchain is the
	// block specified in the provided test instance.
	testExpectedTip := func(item fullblocktests.ExpectedTip) {
		blockHeight := item.Height
		block := btcutil.NewBlock(item.Block)
		block.SetHeight(blockHeight)
		t.Logf("Testing tip for block %s (hash %s, height %d)",
			item.Name, block.Hash(), blockHeight)

		// Ensure hash and height match.
		best := chain.BestSnapshot()
		if *best.Hash != item.Block.BlockHash() ||
			best.Height != blockHeight {

			t.Fatalf("block %q (hash %s, height %d) should be "+
				"the current tip -- got (hash %s, height %d)",
				item.Name, block.Hash(), blockHeight, best.Hash,
				best.Height)
		}
	}

	for testNum, test := range tests {
		for itemNum, item := range test {
			switch item := item.(type) {
			case fullblocktests.AcceptedBlock:
				testAcceptedBlock(item)
			case fullblocktests.RejectedBlock:
				testRejectedBlock(item)
			case fullblocktests.RejectedNonCanonicalBlock:
				testRejectedNonCanonicalBlock(item)
			case fullblocktests.OrphanOrRejectedBlock:
				testOrphanOrRejectedBlock(item)
			case fullblocktests.ExpectedTip:
				testExpectedTip(item)
			default:
				t.Fatalf("test #%d, item #%d is not one of "+
					"the supported test instance types -- "+
					"got type: %T", testNum, itemNum, item)
			}
		}
	}
}