// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package core
import (
"errors"
"fmt"
"math/big"
"sort"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/params"
"gopkg.in/karalabe/cookiejar.v2/collections/prque"
)
var (
// Transaction Pool Errors
ErrInvalidSender = errors.New("invalid sender")
ErrNonce = errors.New("nonce too low")
ErrUnderpriced = errors.New("transaction underpriced")
ErrReplaceUnderpriced = errors.New("replacement transaction underpriced")
ErrBalance = errors.New("insufficient balance")
ErrInsufficientFunds = errors.New("insufficient funds for gas * price + value")
ErrIntrinsicGas = errors.New("intrinsic gas too low")
ErrGasLimit = errors.New("exceeds block gas limit")
ErrNegativeValue = errors.New("negative value")
)
var (
minPendingPerAccount = uint64(16) // Min number of guaranteed transaction slots per address
maxPendingTotal = uint64(4096) // Max limit of pending transactions from all accounts (soft)
maxQueuedPerAccount = uint64(64) // Max limit of queued transactions per address
maxQueuedTotal = uint64(1024) // Max limit of queued transactions from all accounts
maxQueuedLifetime = 3 * time.Hour // Max amount of time transactions from idle accounts are queued
minPriceBumpPercent = int64(10) // Minimum price bump needed to replace an old transaction
evictionInterval = time.Minute // Time interval to check for evictable transactions
statsReportInterval = 8 * time.Second // Time interval to report transaction pool stats
)
var (
// Metrics for the pending pool
pendingDiscardCounter = metrics.NewCounter("txpool/pending/discard")
pendingReplaceCounter = metrics.NewCounter("txpool/pending/replace")
pendingRLCounter = metrics.NewCounter("txpool/pending/ratelimit") // Dropped due to rate limiting
pendingNofundsCounter = metrics.NewCounter("txpool/pending/nofunds") // Dropped due to out-of-funds
// Metrics for the queued pool
queuedDiscardCounter = metrics.NewCounter("txpool/queued/discard")
queuedReplaceCounter = metrics.NewCounter("txpool/queued/replace")
queuedRLCounter = metrics.NewCounter("txpool/queued/ratelimit") // Dropped due to rate limiting
queuedNofundsCounter = metrics.NewCounter("txpool/queued/nofunds") // Dropped due to out-of-funds
// General tx metrics
invalidTxCounter = metrics.NewCounter("txpool/invalid")
underpricedTxCounter = metrics.NewCounter("txpool/underpriced")
)
type stateFn func() (*state.StateDB, error)
// TxPool contains all currently known transactions. Transactions
// enter the pool when they are received from the network or submitted
// locally. They exit the pool when they are included in the blockchain.
//
// The pool separates processable transactions (which can be applied to the
// current state) and future transactions. Transactions move between those
// two states over time as they are received and processed.
type TxPool struct {
config *params.ChainConfig
currentState stateFn // The state function which will allow us to do some pre checks
pendingState *state.ManagedState
gasLimit func() *big.Int // The current gas limit function callback
gasPrice *big.Int
eventMux *event.TypeMux
events *event.TypeMuxSubscription
locals *txSet
signer types.Signer
mu sync.RWMutex
pending map[common.Address]*txList // All currently processable transactions
queue map[common.Address]*txList // Queued but non-processable transactions
beats map[common.Address]time.Time // Last heartbeat from each known account
all map[common.Hash]*types.Transaction // All transactions to allow lookups
priced *txPricedList // All transactions sorted by price
wg sync.WaitGroup // for shutdown sync
quit chan struct{}
homestead bool
}
func NewTxPool(config *params.ChainConfig, eventMux *event.TypeMux, currentStateFn stateFn, gasLimitFn func() *big.Int) *TxPool {
pool := &TxPool{
config: config,
signer: types.NewEIP155Signer(config.ChainId),
pending: make(map[common.Address]*txList),
queue: make(map[common.Address]*txList),
beats: make(map[common.Address]time.Time),
all: make(map[common.Hash]*types.Transaction),
eventMux: eventMux,
currentState: currentStateFn,
gasLimit: gasLimitFn,
gasPrice: big.NewInt(1),
pendingState: nil,
locals: newTxSet(),
events: eventMux.Subscribe(ChainHeadEvent{}, RemovedTransactionEvent{}),
quit: make(chan struct{}),
}
pool.priced = newTxPricedList(&pool.all)
pool.resetState()
pool.wg.Add(2)
go pool.eventLoop()
go pool.expirationLoop()
return pool
}
func (pool *TxPool) eventLoop() {
defer pool.wg.Done()
// Start a ticker and keep track of interesting pool stats to report
var prevPending, prevQueued, prevStales int
report := time.NewTicker(statsReportInterval)
defer report.Stop()
// Track chain events. When a chain events occurs (new chain canon block)
// we need to know the new state. The new state will help us determine
// the nonces in the managed state
for {
select {
// Handle any events fired by the system
case ev, ok := <-pool.events.Chan():
if !ok {
return
}
switch ev := ev.Data.(type) {
case ChainHeadEvent:
pool.mu.Lock()
if ev.Block != nil {
if pool.config.IsHomestead(ev.Block.Number()) {
pool.homestead = true
}
}
pool.resetState()
pool.mu.Unlock()
case RemovedTransactionEvent:
pool.AddBatch(ev.Txs)
}
// Handle stats reporting ticks
case <-report.C:
pool.mu.RLock()
pending, queued := pool.stats()
stales := pool.priced.stales
pool.mu.RUnlock()
if pending != prevPending || queued != prevQueued || stales != prevStales {
log.Debug("Transaction pool status report", "executable", pending, "queued", queued, "stales", stales)
prevPending, prevQueued, prevStales = pending, queued, stales
}
}
}
}
func (pool *TxPool) resetState() {
currentState, err := pool.currentState()
if err != nil {
log.Error("Failed reset txpool state", "err", err)
return
}
pool.pendingState = state.ManageState(currentState)
// validate the pool of pending transactions, this will remove
// any transactions that have been included in the block or
// have been invalidated because of another transaction (e.g.
// higher gas price)
pool.demoteUnexecutables(currentState)
// Update all accounts to the latest known pending nonce
for addr, list := range pool.pending {
txs := list.Flatten() // Heavy but will be cached and is needed by the miner anyway
pool.pendingState.SetNonce(addr, txs[len(txs)-1].Nonce()+1)
}
// Check the queue and move transactions over to the pending if possible
// or remove those that have become invalid
pool.promoteExecutables(currentState)
}
// Stop terminates the transaction pool.
func (pool *TxPool) Stop() {
pool.events.Unsubscribe()
close(pool.quit)
pool.wg.Wait()
log.Info("Transaction pool stopped")
}
// GasPrice returns the current gas price enforced by the transaction pool.
func (pool *TxPool) GasPrice() *big.Int {
pool.mu.RLock()
defer pool.mu.RUnlock()
return new(big.Int).Set(pool.gasPrice)
}
// SetGasPrice updates the minimum price required by the transaction pool for a
// new transaction, and drops all transactions below this threshold.
func (pool *TxPool) SetGasPrice(price *big.Int) {
pool.mu.Lock()
defer pool.mu.Unlock()
pool.gasPrice = price
for _, tx := range pool.priced.Cap(price, pool.locals) {
pool.removeTx(tx.Hash())
}
log.Info("Transaction pool price threshold updated", "price", price)
}
// State returns the virtual managed state of the transaction pool.
func (pool *TxPool) State() *state.ManagedState {
pool.mu.RLock()
defer pool.mu.RUnlock()
return pool.pendingState
}
// Stats retrieves the current pool stats, namely the number of pending and the
// number of queued (non-executable) transactions.
func (pool *TxPool) Stats() (int, int) {
pool.mu.RLock()
defer pool.mu.RUnlock()
return pool.stats()
}
// stats retrieves the current pool stats, namely the number of pending and the
// number of queued (non-executable) transactions.
func (pool *TxPool) stats() (int, int) {
pending := 0
for _, list := range pool.pending {
pending += list.Len()
}
queued := 0
for _, list := range pool.queue {
queued += list.Len()
}
return pending, queued
}
// Content retrieves the data content of the transaction pool, returning all the
// pending as well as queued transactions, grouped by account and sorted by nonce.
func (pool *TxPool) Content() (map[common.Address]types.Transactions, map[common.Address]types.Transactions) {
pool.mu.RLock()
defer pool.mu.RUnlock()
pending := make(map[common.Address]types.Transactions)
for addr, list := range pool.pending {
pending[addr] = list.Flatten()
}
queued := make(map[common.Address]types.Transactions)
for addr, list := range pool.queue {
queued[addr] = list.Flatten()
}
return pending, queued
}
// Pending retrieves all currently processable transactions, groupped by origin
// account and sorted by nonce. The returned transaction set is a copy and can be
// freely modified by calling code.
func (pool *TxPool) Pending() (map[common.Address]types.Transactions, error) {
pool.mu.Lock()
defer pool.mu.Unlock()
state, err := pool.currentState()
if err != nil {
return nil, err
}
// check queue first
pool.promoteExecutables(state)
// invalidate any txs
pool.demoteUnexecutables(state)
pending := make(map[common.Address]types.Transactions)
for addr, list := range pool.pending {
pending[addr] = list.Flatten()
}
return pending, nil
}
// SetLocal marks a transaction as local, skipping gas price
// check against local miner minimum in the future
func (pool *TxPool) SetLocal(tx *types.Transaction) {
pool.mu.Lock()
defer pool.mu.Unlock()
pool.locals.add(tx.Hash())
}
// validateTx checks whether a transaction is valid according
// to the consensus rules.
func (pool *TxPool) validateTx(tx *types.Transaction) error {
local := pool.locals.contains(tx.Hash())
// Drop transactions under our own minimal accepted gas price
if !local && pool.gasPrice.Cmp(tx.GasPrice()) > 0 {
return ErrUnderpriced
}
currentState, err := pool.currentState()
if err != nil {
return err
}
from, err := types.Sender(pool.signer, tx)
if err != nil {
return ErrInvalidSender
}
// Last but not least check for nonce errors
if currentState.GetNonce(from) > tx.Nonce() {
return ErrNonce
}
// Check the transaction doesn't exceed the current
// block limit gas.
if pool.gasLimit().Cmp(tx.Gas()) < 0 {
return ErrGasLimit
}
// Transactions can't be negative. This may never happen
// using RLP decoded transactions but may occur if you create
// a transaction using the RPC for example.
if tx.Value().Sign() < 0 {
return ErrNegativeValue
}
// Transactor should have enough funds to cover the costs
// cost == V + GP * GL
if currentState.GetBalance(from).Cmp(tx.Cost()) < 0 {
return ErrInsufficientFunds
}
intrGas := IntrinsicGas(tx.Data(), tx.To() == nil, pool.homestead)
if tx.Gas().Cmp(intrGas) < 0 {
return ErrIntrinsicGas
}
return nil
}
// add validates a transaction and inserts it into the non-executable queue for
// later pending promotion and execution. If the transaction is a replacement for
// an already pending or queued one, it overwrites the previous and returns this
// so outer code doesn't uselessly call promote.
func (pool *TxPool) add(tx *types.Transaction) (bool, error) {
// If the transaction is already known, discard it
hash := tx.Hash()
if pool.all[hash] != nil {
log.Trace("Discarding already known transaction", "hash", hash)
return false, fmt.Errorf("known transaction: %x", hash)
}
// If the transaction fails basic validation, discard it
if err := pool.validateTx(tx); err != nil {
log.Trace("Discarding invalid transaction", "hash", hash, "err", err)
invalidTxCounter.Inc(1)
return false, err
}
// If the transaction pool is full, discard underpriced transactions
if uint64(len(pool.all)) >= maxPendingTotal+maxQueuedTotal {
// If the new transaction is underpriced, don't accept it
if pool.priced.Underpriced(tx, pool.locals) {
log.Trace("Discarding underpriced transaction", "hash", hash, "price", tx.GasPrice())
underpricedTxCounter.Inc(1)
return false, ErrUnderpriced
}
// New transaction is better than our worse ones, make room for it
drop := pool.priced.Discard(len(pool.all)-int(maxPendingTotal+maxQueuedTotal-1), pool.locals)
for _, tx := range drop {
log.Trace("Discarding freshly underpriced transaction", "hash", tx.Hash(), "price", tx.GasPrice())
underpricedTxCounter.Inc(1)
pool.removeTx(tx.Hash())
}
}
// If the transaction is replacing an already pending one, do directly
from, _ := types.Sender(pool.signer, tx) // already validated
if list := pool.pending[from]; list != nil && list.Overlaps(tx) {
// Nonce already pending, check if required price bump is met
inserted, old := list.Add(tx)
if !inserted {
pendingDiscardCounter.Inc(1)
return false, ErrReplaceUnderpriced
}
// New transaction is better, replace old one
if old != nil {
delete(pool.all, old.Hash())
pool.priced.Removed()
pendingReplaceCounter.Inc(1)
}
pool.all[tx.Hash()] = tx
pool.priced.Put(tx)
log.Trace("Pooled new executable transaction", "hash", hash, "from", from, "to", tx.To())
return old != nil, nil
}
// New transaction isn't replacing a pending one, push into queue
replace, err := pool.enqueueTx(hash, tx)
if err != nil {
return false, err
}
log.Trace("Pooled new future transaction", "hash", hash, "from", from, "to", tx.To())
return replace, nil
}
// enqueueTx inserts a new transaction into the non-executable transaction queue.
//
// Note, this method assumes the pool lock is held!
func (pool *TxPool) enqueueTx(hash common.Hash, tx *types.Transaction) (bool, error) {
// Try to insert the transaction into the future queue
from, _ := types.Sender(pool.signer, tx) // already validated
if pool.queue[from] == nil {
pool.queue[from] = newTxList(false)
}
inserted, old := pool.queue[from].Add(tx)
if !inserted {
// An older transaction was better, discard this
queuedDiscardCounter.Inc(1)
return false, ErrReplaceUnderpriced
}
// Discard any previous transaction and mark this
if old != nil {
delete(pool.all, old.Hash())
pool.priced.Removed()
queuedReplaceCounter.Inc(1)
}
pool.all[hash] = tx
pool.priced.Put(tx)
return old != nil, nil
}
// promoteTx adds a transaction to the pending (processable) list of transactions.
//
// Note, this method assumes the pool lock is held!
func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx *types.Transaction) {
// Try to insert the transaction into the pending queue
if pool.pending[addr] == nil {
pool.pending[addr] = newTxList(true)
}
list := pool.pending[addr]
inserted, old := list.Add(tx)
if !inserted {
// An older transaction was better, discard this
delete(pool.all, hash)
pool.priced.Removed()
pendingDiscardCounter.Inc(1)
return
}
// Otherwise discard any previous transaction and mark this
if old != nil {
delete(pool.all, old.Hash())
pool.priced.Removed()
pendingReplaceCounter.Inc(1)
}
// Failsafe to work around direct pending inserts (tests)
if pool.all[hash] == nil {
pool.all[hash] = tx
pool.priced.Put(tx)
}
// Set the potentially new pending nonce and notify any subsystems of the new tx
pool.beats[addr] = time.Now()
pool.pendingState.SetNonce(addr, tx.Nonce()+1)
go pool.eventMux.Post(TxPreEvent{tx})
}
// Add queues a single transaction in the pool if it is valid.
func (pool *TxPool) Add(tx *types.Transaction) error {
pool.mu.Lock()
defer pool.mu.Unlock()
// Try to inject the transaction and update any state
replace, err := pool.add(tx)
if err != nil {
return err
}
state, err := pool.currentState()
if err != nil {
return err
}
// If we added a new transaction, run promotion checks and return
if !replace {
pool.promoteExecutables(state)
}
return nil
}
// AddBatch attempts to queue a batch of transactions.
func (pool *TxPool) AddBatch(txs []*types.Transaction) error {
pool.mu.Lock()
defer pool.mu.Unlock()
// Add the batch of transaction, tracking the accepted ones
replaced, added := true, 0
for _, tx := range txs {
if replace, err := pool.add(tx); err == nil {
added++
if !replace {
replaced = false
}
}
}
// Only reprocess the internal state if something was actually added
if added > 0 {
state, err := pool.currentState()
if err != nil {
return err
}
if !replaced {
pool.promoteExecutables(state)
}
}
return nil
}
// Get returns a transaction if it is contained in the pool
// and nil otherwise.
func (pool *TxPool) Get(hash common.Hash) *types.Transaction {
pool.mu.RLock()
defer pool.mu.RUnlock()
return pool.all[hash]
}
// Remove removes the transaction with the given hash from the pool.
func (pool *TxPool) Remove(hash common.Hash) {
pool.mu.Lock()
defer pool.mu.Unlock()
pool.removeTx(hash)
}
// RemoveBatch removes all given transactions from the pool.
func (pool *TxPool) RemoveBatch(txs types.Transactions) {
pool.mu.Lock()
defer pool.mu.Unlock()
for _, tx := range txs {
pool.removeTx(tx.Hash())
}
}
// removeTx removes a single transaction from the queue, moving all subsequent
// transactions back to the future queue.
func (pool *TxPool) removeTx(hash common.Hash) {
// Fetch the transaction we wish to delete
tx, ok := pool.all[hash]
if !ok {
return
}
addr, _ := types.Sender(pool.signer, tx) // already validated during insertion
// Remove it from the list of known transactions
delete(pool.all, hash)
pool.priced.Removed()
// Remove the transaction from the pending lists and reset the account nonce
if pending := pool.pending[addr]; pending != nil {
if removed, invalids := pending.Remove(tx); removed {
// If no more transactions are left, remove the list
if pending.Empty() {
delete(pool.pending, addr)
delete(pool.beats, addr)
} else {
// Otherwise postpone any invalidated transactions
for _, tx := range invalids {
pool.enqueueTx(tx.Hash(), tx)
}
}
// Update the account nonce if needed
if nonce := tx.Nonce(); pool.pendingState.GetNonce(addr) > nonce {
pool.pendingState.SetNonce(addr, tx.Nonce())
}
}
}
// Transaction is in the future queue
if future := pool.queue[addr]; future != nil {
future.Remove(tx)
if future.Empty() {
delete(pool.queue, addr)
}
}
}
// promoteExecutables moves transactions that have become processable from the
// future queue to the set of pending transactions. During this process, all
// invalidated transactions (low nonce, low balance) are deleted.
func (pool *TxPool) promoteExecutables(state *state.StateDB) {
// Iterate over all accounts and promote any executable transactions
queued := uint64(0)
for addr, list := range pool.queue {
// Drop all transactions that are deemed too old (low nonce)
for _, tx := range list.Forward(state.GetNonce(addr)) {
hash := tx.Hash()
log.Trace("Removed old queued transaction", "hash", hash)
delete(pool.all, hash)
pool.priced.Removed()
}
// Drop all transactions that are too costly (low balance)
drops, _ := list.Filter(state.GetBalance(addr))
for _, tx := range drops {
hash := tx.Hash()
log.Trace("Removed unpayable queued transaction", "hash", hash)
delete(pool.all, hash)
pool.priced.Removed()
queuedNofundsCounter.Inc(1)
}
// Gather all executable transactions and promote them
for _, tx := range list.Ready(pool.pendingState.GetNonce(addr)) {
hash := tx.Hash()
log.Trace("Promoting queued transaction", "hash", hash)
pool.promoteTx(addr, hash, tx)
}
// Drop all transactions over the allowed limit
for _, tx := range list.Cap(int(maxQueuedPerAccount)) {
hash := tx.Hash()
log.Trace("Removed cap-exceeding queued transaction", "hash", hash)
delete(pool.all, hash)
pool.priced.Removed()
queuedRLCounter.Inc(1)
}
queued += uint64(list.Len())
// Delete the entire queue entry if it became empty.
if list.Empty() {
delete(pool.queue, addr)
}
}
// If the pending limit is overflown, start equalizing allowances
pending := uint64(0)
for _, list := range pool.pending {
pending += uint64(list.Len())
}
if pending > maxPendingTotal {
pendingBeforeCap := pending
// Assemble a spam order to penalize large transactors first
spammers := prque.New()
for addr, list := range pool.pending {
// Only evict transactions from high rollers
if uint64(list.Len()) > minPendingPerAccount {
// Skip local accounts as pools should maintain backlogs for themselves
for _, tx := range list.txs.items {
if !pool.locals.contains(tx.Hash()) {
spammers.Push(addr, float32(list.Len()))
}
break // Checking on transaction for locality is enough
}
}
}
// Gradually drop transactions from offenders
offenders := []common.Address{}
for pending > maxPendingTotal && !spammers.Empty() {
// Retrieve the next offender if not local address
offender, _ := spammers.Pop()
offenders = append(offenders, offender.(common.Address))
// Equalize balances until all the same or below threshold
if len(offenders) > 1 {
// Calculate the equalization threshold for all current offenders
threshold := pool.pending[offender.(common.Address)].Len()
// Iteratively reduce all offenders until below limit or threshold reached
for pending > maxPendingTotal && pool.pending[offenders[len(offenders)-2]].Len() > threshold {
for i := 0; i < len(offenders)-1; i++ {
list := pool.pending[offenders[i]]
list.Cap(list.Len() - 1)
pending--
}
}
}
}
// If still above threshold, reduce to limit or min allowance
if pending > maxPendingTotal && len(offenders) > 0 {
for pending > maxPendingTotal && uint64(pool.pending[offenders[len(offenders)-1]].Len()) > minPendingPerAccount {
for _, addr := range offenders {
list := pool.pending[addr]
list.Cap(list.Len() - 1)
pending--
}
}
}
pendingRLCounter.Inc(int64(pendingBeforeCap - pending))
}
// If we've queued more transactions than the hard limit, drop oldest ones
if queued > maxQueuedTotal {
// Sort all accounts with queued transactions by heartbeat
addresses := make(addresssByHeartbeat, 0, len(pool.queue))
for addr := range pool.queue {
addresses = append(addresses, addressByHeartbeat{addr, pool.beats[addr]})
}
sort.Sort(addresses)
// Drop transactions until the total is below the limit
for drop := queued - maxQueuedTotal; drop > 0; {
addr := addresses[len(addresses)-1]
list := pool.queue[addr.address]
addresses = addresses[:len(addresses)-1]
// Drop all transactions if they are less than the overflow
if size := uint64(list.Len()); size <= drop {
for _, tx := range list.Flatten() {
pool.removeTx(tx.Hash())
}
drop -= size
queuedRLCounter.Inc(int64(size))
continue
}
// Otherwise drop only last few transactions
txs := list.Flatten()
for i := len(txs) - 1; i >= 0 && drop > 0; i-- {
pool.removeTx(txs[i].Hash())
drop--
queuedRLCounter.Inc(1)
}
}
}
}
// demoteUnexecutables removes invalid and processed transactions from the pools
// executable/pending queue and any subsequent transactions that become unexecutable
// are moved back into the future queue.
func (pool *TxPool) demoteUnexecutables(state *state.StateDB) {
// Iterate over all accounts and demote any non-executable transactions
for addr, list := range pool.pending {
nonce := state.GetNonce(addr)
// Drop all transactions that are deemed too old (low nonce)
for _, tx := range list.Forward(nonce) {
hash := tx.Hash()
log.Trace("Removed old pending transaction", "hash", hash)
delete(pool.all, hash)
pool.priced.Removed()
}
// Drop all transactions that are too costly (low balance), and queue any invalids back for later
drops, invalids := list.Filter(state.GetBalance(addr))
for _, tx := range drops {
hash := tx.Hash()
log.Trace("Removed unpayable pending transaction", "hash", hash)
delete(pool.all, hash)
pool.priced.Removed()
pendingNofundsCounter.Inc(1)
}
for _, tx := range invalids {
hash := tx.Hash()
log.Trace("Demoting pending transaction", "hash", hash)
pool.enqueueTx(hash, tx)
}
// Delete the entire queue entry if it became empty.
if list.Empty() {
delete(pool.pending, addr)
delete(pool.beats, addr)
}
}
}
// expirationLoop is a loop that periodically iterates over all accounts with
// queued transactions and drop all that have been inactive for a prolonged amount
// of time.
func (pool *TxPool) expirationLoop() {
defer pool.wg.Done()
evict := time.NewTicker(evictionInterval)
defer evict.Stop()
for {
select {
case <-evict.C:
pool.mu.Lock()
for addr := range pool.queue {
if time.Since(pool.beats[addr]) > maxQueuedLifetime {
for _, tx := range pool.queue[addr].Flatten() {
pool.removeTx(tx.Hash())
}
}
}
pool.mu.Unlock()
case <-pool.quit:
return
}
}
}
// addressByHeartbeat is an account address tagged with its last activity timestamp.
type addressByHeartbeat struct {
address common.Address
heartbeat time.Time
}
type addresssByHeartbeat []addressByHeartbeat
func (a addresssByHeartbeat) Len() int { return len(a) }
func (a addresssByHeartbeat) Less(i, j int) bool { return a[i].heartbeat.Before(a[j].heartbeat) }
func (a addresssByHeartbeat) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
// txSet represents a set of transaction hashes in which entries
// are automatically dropped after txSetDuration time
type txSet struct {
txMap map[common.Hash]struct{}
txOrd map[uint64]txOrdType
addPtr, delPtr uint64
}
const txSetDuration = time.Hour * 2
// txOrdType represents an entry in the time-ordered list of transaction hashes
type txOrdType struct {
hash common.Hash
time time.Time
}
// newTxSet creates a new transaction set
func newTxSet() *txSet {
return &txSet{
txMap: make(map[common.Hash]struct{}),
txOrd: make(map[uint64]txOrdType),
}
}
// contains returns true if the set contains the given transaction hash
// (not thread safe, should be called from a locked environment)
func (ts *txSet) contains(hash common.Hash) bool {
_, ok := ts.txMap[hash]
return ok
}
// add adds a transaction hash to the set, then removes entries older than txSetDuration
// (not thread safe, should be called from a locked environment)
func (ts *txSet) add(hash common.Hash) {
ts.txMap[hash] = struct{}{}
now := time.Now()
ts.txOrd[ts.addPtr] = txOrdType{hash: hash, time: now}
ts.addPtr++
delBefore := now.Add(-txSetDuration)
for ts.delPtr < ts.addPtr && ts.txOrd[ts.delPtr].time.Before(delBefore) {
delete(ts.txMap, ts.txOrd[ts.delPtr].hash)
delete(ts.txOrd, ts.delPtr)
ts.delPtr++
}
}