// 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
}
// loadUtxoView returns a utxo view loaded from a file.
func loadUtxoView(filename string) (*blockchain.UtxoViewpoint, error) {
// The utxostore file format is:
// <tx hash><serialized utxo len><serialized utxo>
//
// The serialized utxo len is a little endian uint32 and the serialized
// utxo uses the format described in chainio.go.
filename = filepath.Join("testdata", filename)
fi, err := os.Open(filename)
if err != nil {
return nil, err
}
// Choose read based on whether the file is compressed or not.
var r io.Reader
if strings.HasSuffix(filename, ".bz2") {
r = bzip2.NewReader(fi)
} else {
r = fi
}
defer fi.Close()
view := blockchain.NewUtxoViewpoint()
for {
// Hash of the utxo entry.
var hash wire.ShaHash
_, err := io.ReadAtLeast(r, hash[:], len(hash[:]))
if err != nil {
// Expected EOF at the right offset.
if err == io.EOF {
break
}
return nil, err
}
// Num of serialize utxo entry bytes.
var numBytes uint32
err = binary.Read(r, binary.LittleEndian, &numBytes)
if err != nil {
return nil, err
}
// Serialized utxo entry.
serialized := make([]byte, numBytes)
_, err = io.ReadAtLeast(r, serialized, int(numBytes))
if err != nil {
return nil, err
}
// Deserialize it and add it to the view.
utxoEntry, err := blockchain.TstDeserializeUtxoEntry(serialized)
if err != nil {
return nil, err
}
view.Entries()[hash] = utxoEntry
}
return view, nil
}
// newUtxoViewpoint returns a new utxo view populated with outputs of the
// provided source transactions as if there were available at the respective
// block height specified in the heights slice. The length of the source txns
// and source tx heights must match or it will panic.
func newUtxoViewpoint(sourceTxns []*wire.MsgTx, sourceTxHeights []int32) *blockchain.UtxoViewpoint {
if len(sourceTxns) != len(sourceTxHeights) {
panic("each transaction must have its block height specified")
}
view := blockchain.NewUtxoViewpoint()
for i, tx := range sourceTxns {
view.AddTxOuts(btcutil.NewTx(tx), sourceTxHeights[i])
}
return view
}
// FetchUtxoView loads utxo details about the input transactions referenced by
// the passed transaction from the point of view of the fake chain.
// It also attempts to fetch the utxo details for the transaction itself so the
// returned view can be examined for duplicate unspent transaction outputs.
//
// This function is safe for concurrent access however the returned view is NOT.
func (s *fakeChain) FetchUtxoView(tx *btcutil.Tx) (*blockchain.UtxoViewpoint, error) {
s.RLock()
defer s.RUnlock()
// All entries are cloned to ensure modifications to the returned view
// do not affect the fake chain's view.
// Add an entry for the tx itself to the new view.
viewpoint := blockchain.NewUtxoViewpoint()
entry := s.utxos.LookupEntry(tx.Hash())
viewpoint.Entries()[*tx.Hash()] = entry.Clone()
// Add entries for all of the inputs to the tx to the new view.
for _, txIn := range tx.MsgTx().TxIn {
originHash := &txIn.PreviousOutPoint.Hash
entry := s.utxos.LookupEntry(originHash)
viewpoint.Entries()[*originHash] = entry.Clone()
}
return viewpoint, nil
}
// TestCalcSequenceLock tests the LockTimeToSequence function, and the
// CalcSequenceLock method of a Chain instance. The tests exercise several
// combinations of inputs to the CalcSequenceLock function in order to ensure
// the returned SequenceLocks are correct for each test instance.
func TestCalcSequenceLock(t *testing.T) {
fileName := "blk_0_to_4.dat.bz2"
blocks, err := loadBlocks(fileName)
if err != nil {
t.Errorf("Error loading file: %v\n", err)
return
}
// Create a new database and chain instance to run tests against.
chain, teardownFunc, err := chainSetup("haveblock", &chaincfg.MainNetParams)
if err != nil {
t.Errorf("Failed to setup chain instance: %v", err)
return
}
defer teardownFunc()
// Since we're not dealing with the real block chain, disable
// checkpoints and set the coinbase maturity to 1.
chain.DisableCheckpoints(true)
chain.TstSetCoinbaseMaturity(1)
// Load all the blocks into our test chain.
for i := 1; i < len(blocks); i++ {
_, isOrphan, err := chain.ProcessBlock(blocks[i], blockchain.BFNone)
if err != nil {
t.Errorf("ProcessBlock fail on block %v: %v\n", i, err)
return
}
if isOrphan {
t.Errorf("ProcessBlock incorrectly returned block %v "+
"is an orphan\n", i)
return
}
}
// Create with all the utxos within the create created above.
utxoView := blockchain.NewUtxoViewpoint()
for blockHeight, block := range blocks {
for _, tx := range block.Transactions() {
utxoView.AddTxOuts(tx, int32(blockHeight))
}
}
utxoView.SetBestHash(blocks[len(blocks)-1].Hash())
// The median past time from the point of view of the second to last
// block in the chain.
medianTime := blocks[2].MsgBlock().Header.Timestamp.Unix()
// The median past time of the *next* block will be the timestamp of
// the 2nd block due to the way MTP is calculated in order to be
// compatible with Bitcoin Core.
nextMedianTime := blocks[2].MsgBlock().Header.Timestamp.Unix()
// We'll refer to this utxo within each input in the transactions
// created below. This block that includes this UTXO has a height of 4.
targetTx := blocks[4].Transactions()[0]
utxo := wire.OutPoint{
Hash: *targetTx.Hash(),
Index: 0,
}
// Add an additional transaction which will serve as our unconfirmed
// output.
var fakeScript []byte
unConfTx := &wire.MsgTx{
TxOut: []*wire.TxOut{{
PkScript: fakeScript,
Value: 5,
}},
}
unConfUtxo := wire.OutPoint{
Hash: unConfTx.TxHash(),
Index: 0,
}
// Adding a utxo with a height of 0x7fffffff indicates that the output
// is currently unmined.
utxoView.AddTxOuts(btcutil.NewTx(unConfTx), 0x7fffffff)
tests := []struct {
tx *btcutil.Tx
view *blockchain.UtxoViewpoint
want *blockchain.SequenceLock
mempool bool
}{
// A transaction of version one should disable sequence locks
// as the new sequence number semantics only apply to
// transactions version 2 or higher.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 1,
TxIn: []*wire.TxIn{{
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(false, 3),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: -1,
BlockHeight: -1,
},
},
// A transaction with a single input, that a max int sequence
// number. This sequence number has the high bit set, so
// sequence locks should be disabled.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: utxo,
Sequence: wire.MaxTxInSequenceNum,
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: -1,
BlockHeight: -1,
},
},
// A transaction with a single input whose lock time is
// expressed in seconds. However, the specified lock time is
// below the required floor for time based lock times since
// they have time granularity of 512 seconds. As a result, the
// seconds lock-time should be just before the median time of
// the targeted block.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(true, 2),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: medianTime - 1,
BlockHeight: -1,
},
},
// A transaction with a single input whose lock time is
// expressed in seconds. The number of seconds should be 1023
// seconds after the median past time of the last block in the
// chain.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(true, 1024),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: medianTime + 1023,
BlockHeight: -1,
},
},
// A transaction with multiple inputs. The first input has a
// sequence lock in blocks with a value of 4. The last input
// has a sequence number with a value of 5, but has the disable
// bit set. So the first lock should be selected as it's the
// target lock as its the furthest in the future lock that
// isn't disabled.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(true, 2560),
}, {
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(false, 3) |
wire.SequenceLockTimeDisabled,
}, {
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(false, 3),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: medianTime + (5 << wire.SequenceLockTimeGranularity) - 1,
BlockHeight: 6,
},
},
// Transaction has a single input spending the genesis block
// transaction. The input's sequence number is encodes a
// relative lock-time in blocks (3 blocks). The sequence lock
// should have a value of -1 for seconds, but a block height of
// 6 meaning it can be included at height 7.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(false, 3),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: -1,
BlockHeight: 6,
},
},
// A transaction with two inputs with lock times expressed in
// seconds. The selected sequence lock value for seconds should
// be the time further in the future.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(true, 5120),
}, {
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(true, 2560),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: medianTime + (10 << wire.SequenceLockTimeGranularity) - 1,
BlockHeight: -1,
},
},
// A transaction with two inputs with lock times expressed in
// seconds. The selected sequence lock value for blocks should
// be the height further in the future, so a height of 10
// indicating in can be included at height 7.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(false, 1),
}, {
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(false, 7),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: -1,
BlockHeight: 10,
},
},
// A transaction with multiple inputs. Two inputs are time
// based, and the other two are input maturity based. The lock
// lying further into the future for both inputs should be
// chosen.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(true, 2560),
}, {
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(true, 6656),
}, {
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(false, 3),
}, {
PreviousOutPoint: utxo,
Sequence: blockchain.LockTimeToSequence(false, 9),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: medianTime + (13 << wire.SequenceLockTimeGranularity) - 1,
BlockHeight: 12,
},
},
// A transaction with a single unconfirmed input. As the input
// is confirmed, the height of the input should be interpreted
// as the height of the *next* block. So the relative block
// lock should be based from a height of 5 rather than a height
// of 4.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: unConfUtxo,
Sequence: blockchain.LockTimeToSequence(false, 2),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: -1,
BlockHeight: 6,
},
},
// A transaction with a single unconfirmed input. The input has
// a time based lock, so the lock time should be based off the
// MTP of the *next* block.
{
tx: btcutil.NewTx(&wire.MsgTx{
Version: 2,
TxIn: []*wire.TxIn{{
PreviousOutPoint: unConfUtxo,
Sequence: blockchain.LockTimeToSequence(true, 1024),
}},
}),
view: utxoView,
want: &blockchain.SequenceLock{
Seconds: nextMedianTime + 1023,
BlockHeight: -1,
},
},
}
t.Logf("Running %v SequenceLock tests", len(tests))
for i, test := range tests {
seqLock, err := chain.CalcSequenceLock(test.tx, test.view, test.mempool)
if err != nil {
t.Fatalf("test #%d, unable to calc sequence lock: %v", i, err)
}
if seqLock.Seconds != test.want.Seconds {
t.Fatalf("test #%d got %v seconds want %v seconds",
i, seqLock.Seconds, test.want.Seconds)
}
if seqLock.BlockHeight != test.want.BlockHeight {
t.Fatalf("test #%d got height of %v want height of %v ",
i, seqLock.BlockHeight, test.want.BlockHeight)
}
}
}
// 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 NewBlockTemplate(policy *mining.Policy, server *server, payToAddress btcutil.Address) (*BlockTemplate, error) {
var txSource mining.TxSource = server.txMemPool
blockManager := server.blockManager
timeSource := server.timeSource
chainState := &blockManager.chainState
// Extend the most recently known best block.
chainState.Lock()
prevHash := chainState.newestHash
nextBlockHeight := chainState.newestHeight + 1
chainState.Unlock()
// 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
}
coinbaseTx, err := createCoinbaseTx(coinbaseScript, nextBlockHeight,
payToAddress)
if err != nil {
return nil, err
}
numCoinbaseSigOps := int64(blockchain.CountSigOps(coinbaseTx))
// 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 := txSource.MiningDescs()
sortedByFee := 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[wire.ShaHash]*list.List)
// 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))
txSigOpCounts := make([]int64, 0, len(sourceTxns))
txFees = append(txFees, -1) // Updated once known
txSigOpCounts = append(txSigOpCounts, numCoinbaseSigOps)
minrLog.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) {
minrLog.Tracef("Skipping coinbase tx %s", tx.Sha())
continue
}
if !blockchain.IsFinalizedTransaction(tx, nextBlockHeight,
timeSource.AdjustedTime()) {
minrLog.Tracef("Skipping non-finalized tx %s", tx.Sha())
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 := blockManager.chain.FetchUtxoView(tx)
if err != nil {
minrLog.Warnf("Unable to fetch utxo view for tx %s: "+
"%v", tx.Sha(), 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 !txSource.HaveTransaction(originHash) {
minrLog.Tracef("Skipping tx %s because "+
"it references unspent output "+
"%s which is not available",
tx.Sha(), txIn.PreviousOutPoint)
continue mempoolLoop
}
// The transaction is referencing another
// transaction in the source pool, so setup an
// ordering dependency.
depList, exists := dependers[*originHash]
if !exists {
depList = list.New()
dependers[*originHash] = depList
}
depList.PushBack(prioItem)
if prioItem.dependsOn == nil {
prioItem.dependsOn = make(
map[wire.ShaHash]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.
txSize := tx.MsgTx().SerializeSize()
prioItem.feePerKB = (txDesc.Fee * 1000) / int64(txSize)
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)
}
minrLog.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.
blockSize := blockHeaderOverhead + uint32(coinbaseTx.MsgTx().SerializeSize())
blockSigOps := numCoinbaseSigOps
totalFees := int64(0)
// 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
// Grab the list of transactions which depend on this one (if
// any) and remove the entry for this transaction as it will
// either be included or skipped, but in either case the deps
// are no longer needed.
deps := dependers[*tx.Sha()]
delete(dependers, *tx.Sha())
// Enforce maximum block size. Also check for overflow.
txSize := uint32(tx.MsgTx().SerializeSize())
blockPlusTxSize := blockSize + txSize
if blockPlusTxSize < blockSize || blockPlusTxSize >= policy.BlockMaxSize {
minrLog.Tracef("Skipping tx %s because it would exceed "+
"the max block size", tx.Sha())
logSkippedDeps(tx, deps)
continue
}
// Enforce maximum signature operations per block. Also check
// for overflow.
numSigOps := int64(blockchain.CountSigOps(tx))
if blockSigOps+numSigOps < blockSigOps ||
blockSigOps+numSigOps > blockchain.MaxSigOpsPerBlock {
minrLog.Tracef("Skipping tx %s because it would "+
"exceed the maximum sigops per block", tx.Sha())
logSkippedDeps(tx, deps)
continue
}
numP2SHSigOps, err := blockchain.CountP2SHSigOps(tx, false,
blockUtxos)
if err != nil {
minrLog.Tracef("Skipping tx %s due to error in "+
"CountP2SHSigOps: %v", tx.Sha(), err)
logSkippedDeps(tx, deps)
continue
}
numSigOps += int64(numP2SHSigOps)
if blockSigOps+numSigOps < blockSigOps ||
blockSigOps+numSigOps > blockchain.MaxSigOpsPerBlock {
minrLog.Tracef("Skipping tx %s because it would "+
"exceed the maximum sigops per block (p2sh)",
tx.Sha())
logSkippedDeps(tx, deps)
continue
}
// Skip free transactions once the block is larger than the
// minimum block size.
if sortedByFee &&
prioItem.feePerKB < int64(policy.TxMinFreeFee) &&
blockPlusTxSize >= policy.BlockMinSize {
minrLog.Tracef("Skipping tx %s with feePerKB %d "+
"< TxMinFreeFee %d and block size %d >= "+
"minBlockSize %d", tx.Sha(), prioItem.feePerKB,
policy.TxMinFreeFee, blockPlusTxSize,
policy.BlockMinSize)
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 && (blockPlusTxSize >= policy.BlockPrioritySize ||
prioItem.priority <= minHighPriority) {
minrLog.Tracef("Switching to sort by fees per "+
"kilobyte blockSize %d >= BlockPrioritySize "+
"%d || priority %.2f <= minHighPriority %.2f",
blockPlusTxSize, 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 blockPlusTxSize > 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)
if err != nil {
minrLog.Tracef("Skipping tx %s due to error in "+
"CheckTransactionInputs: %v", tx.Sha(), err)
logSkippedDeps(tx, deps)
continue
}
err = blockchain.ValidateTransactionScripts(tx, blockUtxos,
txscript.StandardVerifyFlags, server.sigCache)
if err != nil {
minrLog.Tracef("Skipping tx %s due to error in "+
"ValidateTransactionScripts: %v", tx.Sha(), 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)
blockSize += txSize
blockSigOps += numSigOps
totalFees += prioItem.fee
txFees = append(txFees, prioItem.fee)
txSigOpCounts = append(txSigOpCounts, numSigOps)
minrLog.Tracef("Adding tx %s (priority %.2f, feePerKB %d)",
prioItem.tx.Sha(), prioItem.priority, prioItem.feePerKB)
// Add transactions which depend on this one (and also do not
// have any other unsatisified dependencies) to the priority
// queue.
if deps != nil {
for e := deps.Front(); e != nil; e = e.Next() {
// Add the transaction to the priority queue if
// there are no more dependencies after this
// one.
item := e.Value.(*txPrioItem)
delete(item.dependsOn, *tx.Sha())
if len(item.dependsOn) == 0 {
heap.Push(priorityQueue, item)
}
}
}
}
// Now that the actual transactions have been selected, update the
// block size for the real transaction count and coinbase value with
// the total fees accordingly.
blockSize -= wire.MaxVarIntPayload -
uint32(wire.VarIntSerializeSize(uint64(len(blockTxns))))
coinbaseTx.MsgTx().TxOut[0].Value += totalFees
txFees[0] = -totalFees
// 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, err := medianAdjustedTime(chainState, timeSource)
if err != nil {
return nil, err
}
reqDifficulty, err := blockManager.chain.CalcNextRequiredDifficulty(ts)
if err != nil {
return nil, err
}
// Create a new block ready to be solved.
merkles := blockchain.BuildMerkleTreeStore(blockTxns)
var msgBlock wire.MsgBlock
msgBlock.Header = wire.BlockHeader{
Version: generatedBlockVersion,
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 := blockManager.chain.CheckConnectBlock(block); err != nil {
return nil, err
}
minrLog.Debugf("Created new block template (%d transactions, %d in "+
"fees, %d signature operations, %d bytes, target difficulty "+
"%064x)", len(msgBlock.Transactions), totalFees, blockSigOps,
blockSize, blockchain.CompactToBig(msgBlock.Header.Bits))
return &BlockTemplate{
Block: &msgBlock,
Fees: txFees,
SigOpCounts: txSigOpCounts,
Height: nextBlockHeight,
ValidPayAddress: payToAddress != nil,
}, nil
}
// newPoolHarness returns a new instance of a pool harness initialized with a
// fake chain and a TxPool bound to it that is configured with a policy suitable
// for testing. Also, the fake chain is populated with the returned spendable
// outputs so the caller can easily create new valid transactions which build
// off of it.
func newPoolHarness(chainParams *chaincfg.Params) (*poolHarness, []spendableOutput, error) {
// Use a hard coded key pair for deterministic results.
keyBytes, err := hex.DecodeString("700868df1838811ffbdf918fb482c1f7e" +
"ad62db4b97bd7012c23e726485e577d")
if err != nil {
return nil, nil, err
}
signKey, signPub := btcec.PrivKeyFromBytes(btcec.S256(), keyBytes)
// Generate associated pay-to-script-hash address and resulting payment
// script.
pubKeyBytes := signPub.SerializeCompressed()
payPubKeyAddr, err := btcutil.NewAddressPubKey(pubKeyBytes, chainParams)
if err != nil {
return nil, nil, err
}
payAddr := payPubKeyAddr.AddressPubKeyHash()
pkScript, err := txscript.PayToAddrScript(payAddr)
if err != nil {
return nil, nil, err
}
// Create a new fake chain and harness bound to it.
chain := &fakeChain{utxos: blockchain.NewUtxoViewpoint()}
harness := poolHarness{
signKey: signKey,
payAddr: payAddr,
payScript: pkScript,
chainParams: chainParams,
chain: chain,
txPool: New(&Config{
Policy: Policy{
DisableRelayPriority: true,
FreeTxRelayLimit: 15.0,
MaxOrphanTxs: 5,
MaxOrphanTxSize: 1000,
MaxSigOpsPerTx: blockchain.MaxSigOpsPerBlock / 5,
MinRelayTxFee: 1000, // 1 Satoshi per byte
MaxTxVersion: 1,
},
ChainParams: chainParams,
FetchUtxoView: chain.FetchUtxoView,
BestHeight: chain.BestHeight,
MedianTimePast: chain.MedianTimePast,
CalcSequenceLock: chain.CalcSequenceLock,
SigCache: nil,
AddrIndex: nil,
}),
}
// Create a single coinbase transaction and add it to the harness
// chain's utxo set and set the harness chain height such that the
// coinbase will mature in the next block. This ensures the txpool
// accepts transactions which spend immature coinbases that will become
// mature in the next block.
numOutputs := uint32(1)
outputs := make([]spendableOutput, 0, numOutputs)
curHeight := harness.chain.BestHeight()
coinbase, err := harness.CreateCoinbaseTx(curHeight+1, numOutputs)
if err != nil {
return nil, nil, err
}
harness.chain.utxos.AddTxOuts(coinbase, curHeight+1)
for i := uint32(0); i < numOutputs; i++ {
outputs = append(outputs, txOutToSpendableOut(coinbase, i))
}
harness.chain.SetHeight(int32(chainParams.CoinbaseMaturity) + curHeight)
harness.chain.SetMedianTimePast(time.Now())
return &harness, outputs, nil
}
