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package mempool
import (
"bytes"
"context"
"errors"
"fmt"
"reflect"
"sync/atomic"
"time"
abci "github.com/tendermint/tendermint/abci/types"
"github.com/tendermint/tendermint/config"
"github.com/tendermint/tendermint/internal/libs/clist"
tmsync "github.com/tendermint/tendermint/internal/libs/sync"
"github.com/tendermint/tendermint/internal/proxy"
"github.com/tendermint/tendermint/libs/log"
tmmath "github.com/tendermint/tendermint/libs/math"
"github.com/tendermint/tendermint/types"
)
var _ Mempool = (*TxMempool)(nil)
// TxMempoolOption sets an optional parameter on the TxMempool.
type TxMempoolOption func(*TxMempool)
// TxMempool defines a prioritized mempool data structure used by the v1 mempool
// reactor. It keeps a thread-safe priority queue of transactions that is used
// when a block proposer constructs a block and a thread-safe linked-list that
// is used to gossip transactions to peers in a FIFO manner.
type TxMempool struct {
logger log.Logger
metrics *Metrics
config *config.MempoolConfig
proxyAppConn proxy.AppConnMempool
// txsAvailable fires once for each height when the mempool is not empty
txsAvailable chan struct{}
notifiedTxsAvailable bool
// height defines the last block height process during Update()
height int64
// sizeBytes defines the total size of the mempool (sum of all tx bytes)
sizeBytes int64
// cache defines a fixed-size cache of already seen transactions as this
// reduces pressure on the proxyApp.
cache TxCache
// txStore defines the main storage of valid transactions. Indexes are built
// on top of this store.
txStore *TxStore
// gossipIndex defines the gossiping index of valid transactions via a
// thread-safe linked-list. We also use the gossip index as a cursor for
// rechecking transactions already in the mempool.
gossipIndex *clist.CList
// recheckCursor and recheckEnd are used as cursors based on the gossip index
// to recheck transactions that are already in the mempool. Iteration is not
// thread-safe and transaction may be mutated in serial order.
//
// XXX/TODO: It might be somewhat of a codesmell to use the gossip index for
// iterator and cursor management when rechecking transactions. If the gossip
// index changes or is removed in a future refactor, this will have to be
// refactored. Instead, we should consider just keeping a slice of a snapshot
// of the mempool's current transactions during Update and an integer cursor
// into that slice. This, however, requires additional O(n) space complexity.
recheckCursor *clist.CElement // next expected response
recheckEnd *clist.CElement // re-checking stops here
// priorityIndex defines the priority index of valid transactions via a
// thread-safe priority queue.
priorityIndex *TxPriorityQueue
// heightIndex defines a height-based, in ascending order, transaction index.
// i.e. older transactions are first.
heightIndex *WrappedTxList
// timestampIndex defines a timestamp-based, in ascending order, transaction
// index. i.e. older transactions are first.
timestampIndex *WrappedTxList
// A read/write lock is used to safe guard updates, insertions and deletions
// from the mempool. A read-lock is implicitly acquired when executing CheckTx,
// however, a caller must explicitly grab a write-lock via Lock when updating
// the mempool via Update().
mtx tmsync.RWMutex
preCheck PreCheckFunc
postCheck PostCheckFunc
}
func NewTxMempool(
logger log.Logger,
cfg *config.MempoolConfig,
proxyAppConn proxy.AppConnMempool,
height int64,
options ...TxMempoolOption,
) *TxMempool {
txmp := &TxMempool{
logger: logger,
config: cfg,
proxyAppConn: proxyAppConn,
height: height,
cache: NopTxCache{},
metrics: NopMetrics(),
txStore: NewTxStore(),
gossipIndex: clist.New(),
priorityIndex: NewTxPriorityQueue(),
heightIndex: NewWrappedTxList(func(wtx1, wtx2 *WrappedTx) bool {
return wtx1.height >= wtx2.height
}),
timestampIndex: NewWrappedTxList(func(wtx1, wtx2 *WrappedTx) bool {
return wtx1.timestamp.After(wtx2.timestamp) || wtx1.timestamp.Equal(wtx2.timestamp)
}),
}
if cfg.CacheSize > 0 {
txmp.cache = NewLRUTxCache(cfg.CacheSize)
}
proxyAppConn.SetResponseCallback(txmp.defaultTxCallback)
for _, opt := range options {
opt(txmp)
}
return txmp
}
// WithPreCheck sets a filter for the mempool to reject a transaction if f(tx)
// returns an error. This is executed before CheckTx. It only applies to the
// first created block. After that, Update() overwrites the existing value.
func WithPreCheck(f PreCheckFunc) TxMempoolOption {
return func(txmp *TxMempool) { txmp.preCheck = f }
}
// WithPostCheck sets a filter for the mempool to reject a transaction if
// f(tx, resp) returns an error. This is executed after CheckTx. It only applies
// to the first created block. After that, Update overwrites the existing value.
func WithPostCheck(f PostCheckFunc) TxMempoolOption {
return func(txmp *TxMempool) { txmp.postCheck = f }
}
// WithMetrics sets the mempool's metrics collector.
func WithMetrics(metrics *Metrics) TxMempoolOption {
return func(txmp *TxMempool) { txmp.metrics = metrics }
}
// Lock obtains a write-lock on the mempool. A caller must be sure to explicitly
// release the lock when finished.
func (txmp *TxMempool) Lock() {
txmp.mtx.Lock()
}
// Unlock releases a write-lock on the mempool.
func (txmp *TxMempool) Unlock() {
txmp.mtx.Unlock()
}
// Size returns the number of valid transactions in the mempool. It is
// thread-safe.
func (txmp *TxMempool) Size() int {
return txmp.txStore.Size()
}
// SizeBytes return the total sum in bytes of all the valid transactions in the
// mempool. It is thread-safe.
func (txmp *TxMempool) SizeBytes() int64 {
return atomic.LoadInt64(&txmp.sizeBytes)
}
// FlushAppConn executes FlushSync on the mempool's proxyAppConn.
//
// NOTE: The caller must obtain a write-lock prior to execution.
func (txmp *TxMempool) FlushAppConn() error {
return txmp.proxyAppConn.FlushSync(context.Background())
}
// WaitForNextTx returns a blocking channel that will be closed when the next
// valid transaction is available to gossip. It is thread-safe.
func (txmp *TxMempool) WaitForNextTx() <-chan struct{} {
return txmp.gossipIndex.WaitChan()
}
// NextGossipTx returns the next valid transaction to gossip. A caller must wait
// for WaitForNextTx to signal a transaction is available to gossip first. It is
// thread-safe.
func (txmp *TxMempool) NextGossipTx() *clist.CElement {
return txmp.gossipIndex.Front()
}
// EnableTxsAvailable enables the mempool to trigger events when transactions
// are available on a block by block basis.
func (txmp *TxMempool) EnableTxsAvailable() {
txmp.mtx.Lock()
defer txmp.mtx.Unlock()
txmp.txsAvailable = make(chan struct{}, 1)
}
// TxsAvailable returns a channel which fires once for every height, and only
// when transactions are available in the mempool. It is thread-safe.
func (txmp *TxMempool) TxsAvailable() <-chan struct{} {
return txmp.txsAvailable
}
// CheckTx executes the ABCI CheckTx method for a given transaction. It acquires
// a read-lock attempts to execute the application's CheckTx ABCI method via
// CheckTxAsync. We return an error if any of the following happen:
//
// - The CheckTxAsync execution fails.
// - The transaction already exists in the cache and we've already received the
// transaction from the peer. Otherwise, if it solely exists in the cache, we
// return nil.
// - The transaction size exceeds the maximum transaction size as defined by the
// configuration provided to the mempool.
// - The transaction fails Pre-Check (if it is defined).
// - The proxyAppConn fails, e.g. the buffer is full.
//
// If the mempool is full, we still execute CheckTx and attempt to find a lower
// priority transaction to evict. If such a transaction exists, we remove the
// lower priority transaction and add the new one with higher priority.
//
// NOTE:
// - The applications' CheckTx implementation may panic.
// - The caller is not to explicitly require any locks for executing CheckTx.
func (txmp *TxMempool) CheckTx(
ctx context.Context,
tx types.Tx,
cb func(*abci.Response),
txInfo TxInfo,
) error {
if ctx == nil {
ctx = context.TODO()
}
txmp.mtx.RLock()
defer txmp.mtx.RUnlock()
if txSize := len(tx); txSize > txmp.config.MaxTxBytes {
return types.ErrTxTooLarge{
Max: txmp.config.MaxTxBytes,
Actual: txSize,
}
}
if txmp.preCheck != nil {
if err := txmp.preCheck(tx); err != nil {
return types.ErrPreCheck{Reason: err}
}
}
if err := txmp.proxyAppConn.Error(); err != nil {
return err
}
txHash := tx.Key()
// We add the transaction to the mempool's cache and if the transaction already
// exists, i.e. false is returned, then we check if we've seen this transaction
// from the same sender and error if we have. Otherwise, we return nil.
if !txmp.cache.Push(tx) {
wtx, ok := txmp.txStore.GetOrSetPeerByTxHash(txHash, txInfo.SenderID)
if wtx != nil && ok {
// We already have the transaction stored and the we've already seen this
// transaction from txInfo.SenderID.
return types.ErrTxInCache
}
txmp.logger.Debug("tx exists already in cache", "tx_hash", tx.Hash())
return nil
}
reqRes, err := txmp.proxyAppConn.CheckTxAsync(ctx, abci.RequestCheckTx{Tx: tx})
if err != nil {
txmp.cache.Remove(tx)
return err
}
reqRes.SetCallback(func(res *abci.Response) {
if txmp.recheckCursor != nil {
panic("recheck cursor is non-nil in CheckTx callback")
}
wtx := &WrappedTx{
tx: tx,
hash: txHash,
timestamp: time.Now().UTC(),
height: txmp.height,
}
txmp.initTxCallback(wtx, res, txInfo)
if cb != nil {
cb(res)
}
})
return nil
}
func (txmp *TxMempool) RemoveTxByKey(txKey types.TxKey) error {
txmp.Lock()
defer txmp.Unlock()
// remove the committed transaction from the transaction store and indexes
if wtx := txmp.txStore.GetTxByHash(txKey); wtx != nil {
txmp.removeTx(wtx, false)
return nil
}
return errors.New("transaction not found")
}
// Flush empties the mempool. It acquires a read-lock, fetches all the
// transactions currently in the transaction store and removes each transaction
// from the store and all indexes and finally resets the cache.
//
// NOTE:
// - Flushing the mempool may leave the mempool in an inconsistent state.
func (txmp *TxMempool) Flush() {
txmp.mtx.RLock()
defer txmp.mtx.RUnlock()
txmp.heightIndex.Reset()
txmp.timestampIndex.Reset()
for _, wtx := range txmp.txStore.GetAllTxs() {
txmp.removeTx(wtx, false)
}
atomic.SwapInt64(&txmp.sizeBytes, 0)
txmp.cache.Reset()
}
// ReapMaxBytesMaxGas returns a list of transactions within the provided size
// and gas constraints. Transaction are retrieved in priority order.
//
// NOTE:
// - Transactions returned are not removed from the mempool transaction
// store or indexes.
func (txmp *TxMempool) ReapMaxBytesMaxGas(maxBytes, maxGas int64) types.Txs {
txmp.mtx.RLock()
defer txmp.mtx.RUnlock()
var (
totalGas int64
totalSize int64
)
// wTxs contains a list of *WrappedTx retrieved from the priority queue that
// need to be re-enqueued prior to returning.
wTxs := make([]*WrappedTx, 0, txmp.priorityIndex.NumTxs())
defer func() {
for _, wtx := range wTxs {
txmp.priorityIndex.PushTx(wtx)
}
}()
txs := make([]types.Tx, 0, txmp.priorityIndex.NumTxs())
for txmp.priorityIndex.NumTxs() > 0 {
wtx := txmp.priorityIndex.PopTx()
txs = append(txs, wtx.tx)
wTxs = append(wTxs, wtx)
size := types.ComputeProtoSizeForTxs([]types.Tx{wtx.tx})
// Ensure we have capacity for the transaction with respect to the
// transaction size.
if maxBytes > -1 && totalSize+size > maxBytes {
return txs[:len(txs)-1]
}
totalSize += size
// ensure we have capacity for the transaction with respect to total gas
gas := totalGas + wtx.gasWanted
if maxGas > -1 && gas > maxGas {
return txs[:len(txs)-1]
}
totalGas = gas
}
return txs
}
// ReapMaxTxs returns a list of transactions within the provided number of
// transactions bound. Transaction are retrieved in priority order.
//
// NOTE:
// - Transactions returned are not removed from the mempool transaction
// store or indexes.
func (txmp *TxMempool) ReapMaxTxs(max int) types.Txs {
txmp.mtx.RLock()
defer txmp.mtx.RUnlock()
numTxs := txmp.priorityIndex.NumTxs()
if max < 0 {
max = numTxs
}
cap := tmmath.MinInt(numTxs, max)
// wTxs contains a list of *WrappedTx retrieved from the priority queue that
// need to be re-enqueued prior to returning.
wTxs := make([]*WrappedTx, 0, cap)
txs := make([]types.Tx, 0, cap)
for txmp.priorityIndex.NumTxs() > 0 && len(txs) < max {
wtx := txmp.priorityIndex.PopTx()
txs = append(txs, wtx.tx)
wTxs = append(wTxs, wtx)
}
for _, wtx := range wTxs {
txmp.priorityIndex.PushTx(wtx)
}
return txs
}
// Update iterates over all the transactions provided by the block producer,
// removes them from the cache (if applicable), and removes
// the transactions from the main transaction store and associated indexes.
// If there are transactions remaining in the mempool, we initiate a
// re-CheckTx for them (if applicable), otherwise, we notify the caller more
// transactions are available.
//
// NOTE:
// - The caller must explicitly acquire a write-lock.
func (txmp *TxMempool) Update(
blockHeight int64,
blockTxs types.Txs,
deliverTxResponses []*abci.ResponseDeliverTx,
newPreFn PreCheckFunc,
newPostFn PostCheckFunc,
) error {
txmp.height = blockHeight
txmp.notifiedTxsAvailable = false
if newPreFn != nil {
txmp.preCheck = newPreFn
}
if newPostFn != nil {
txmp.postCheck = newPostFn
}
for i, tx := range blockTxs {
if deliverTxResponses[i].Code == abci.CodeTypeOK {
// add the valid committed transaction to the cache (if missing)
_ = txmp.cache.Push(tx)
} else if !txmp.config.KeepInvalidTxsInCache {
// allow invalid transactions to be re-submitted
txmp.cache.Remove(tx)
}
// remove the committed transaction from the transaction store and indexes
if wtx := txmp.txStore.GetTxByHash(tx.Key()); wtx != nil {
txmp.removeTx(wtx, false)
}
}
txmp.purgeExpiredTxs(blockHeight)
// If there any uncommitted transactions left in the mempool, we either
// initiate re-CheckTx per remaining transaction or notify that remaining
// transactions are left.
if txmp.Size() > 0 {
if txmp.config.Recheck {
txmp.logger.Debug(
"executing re-CheckTx for all remaining transactions",
"num_txs", txmp.Size(),
"height", blockHeight,
)
txmp.updateReCheckTxs()
} else {
txmp.notifyTxsAvailable()
}
}
txmp.metrics.Size.Set(float64(txmp.Size()))
return nil
}
// initTxCallback is the callback invoked for a new unique transaction after CheckTx
// has been executed by the ABCI application for the first time on that transaction.
// CheckTx can be called again for the same transaction later when re-checking;
// however, this callback will not be called.
//
// initTxCallback runs after the ABCI application executes CheckTx.
// It runs the postCheck hook if one is defined on the mempool.
// If the CheckTx response response code is not OK, or if the postCheck hook
// reports an error, the transaction is rejected. Otherwise, we attempt to insert
// the transaction into the mempool.
//
// When inserting a transaction, we first check if there is sufficient capacity.
// If there is, the transaction is added to the txStore and all indexes.
// Otherwise, if the mempool is full, we attempt to find a lower priority transaction
// to evict in place of the new incoming transaction. If no such transaction exists,
// the new incoming transaction is rejected.
//
// NOTE:
// - An explicit lock is NOT required.
func (txmp *TxMempool) initTxCallback(wtx *WrappedTx, res *abci.Response, txInfo TxInfo) {
checkTxRes, ok := res.Value.(*abci.Response_CheckTx)
if !ok {
return
}
var err error
if txmp.postCheck != nil {
err = txmp.postCheck(wtx.tx, checkTxRes.CheckTx)
}
if err != nil || checkTxRes.CheckTx.Code != abci.CodeTypeOK {
// ignore bad transactions
txmp.logger.Info(
"rejected bad transaction",
"priority", wtx.priority,
"tx", fmt.Sprintf("%X", wtx.tx.Hash()),
"peer_id", txInfo.SenderNodeID,
"code", checkTxRes.CheckTx.Code,
"post_check_err", err,
)
txmp.metrics.FailedTxs.Add(1)
if !txmp.config.KeepInvalidTxsInCache {
txmp.cache.Remove(wtx.tx)
}
if err != nil {
checkTxRes.CheckTx.MempoolError = err.Error()
}
return
}
sender := checkTxRes.CheckTx.Sender
priority := checkTxRes.CheckTx.Priority
if len(sender) > 0 {
if wtx := txmp.txStore.GetTxBySender(sender); wtx != nil {
txmp.logger.Error(
"rejected incoming good transaction; tx already exists for sender",
"tx", fmt.Sprintf("%X", wtx.tx.Hash()),
"sender", sender,
)
txmp.metrics.RejectedTxs.Add(1)
return
}
}
if err := txmp.canAddTx(wtx); err != nil {
evictTxs := txmp.priorityIndex.GetEvictableTxs(
priority,
int64(wtx.Size()),
txmp.SizeBytes(),
txmp.config.MaxTxsBytes,
)
if len(evictTxs) == 0 {
// No room for the new incoming transaction so we just remove it from
// the cache.
txmp.cache.Remove(wtx.tx)
txmp.logger.Error(
"rejected incoming good transaction; mempool full",
"tx", fmt.Sprintf("%X", wtx.tx.Hash()),
"err", err.Error(),
)
txmp.metrics.RejectedTxs.Add(1)
return
}
// evict an existing transaction(s)
//
// NOTE:
// - The transaction, toEvict, can be removed while a concurrent
// reCheckTx callback is being executed for the same transaction.
for _, toEvict := range evictTxs {
txmp.removeTx(toEvict, true)
txmp.logger.Debug(
"evicted existing good transaction; mempool full",
"old_tx", fmt.Sprintf("%X", toEvict.tx.Hash()),
"old_priority", toEvict.priority,
"new_tx", fmt.Sprintf("%X", wtx.tx.Hash()),
"new_priority", wtx.priority,
)
txmp.metrics.EvictedTxs.Add(1)
}
}
wtx.gasWanted = checkTxRes.CheckTx.GasWanted
wtx.priority = priority
wtx.sender = sender
wtx.peers = map[uint16]struct{}{
txInfo.SenderID: {},
}
txmp.metrics.TxSizeBytes.Observe(float64(wtx.Size()))
txmp.metrics.Size.Set(float64(txmp.Size()))
txmp.insertTx(wtx)
txmp.logger.Debug(
"inserted good transaction",
"priority", wtx.priority,
"tx", fmt.Sprintf("%X", wtx.tx.Hash()),
"height", txmp.height,
"num_txs", txmp.Size(),
)
txmp.notifyTxsAvailable()
}
// defaultTxCallback is the CheckTx application callback used when a transaction
// is being re-checked (if re-checking is enabled). The caller must hold a mempool
// write-lock (via Lock()) and when executing Update(), if the mempool is non-empty
// and Recheck is enabled, then all remaining transactions will be rechecked via
// CheckTxAsync. The order transactions are rechecked must be the same as the
// order in which this callback is called.
func (txmp *TxMempool) defaultTxCallback(req *abci.Request, res *abci.Response) {
if txmp.recheckCursor == nil {
return
}
txmp.metrics.RecheckTimes.Add(1)
checkTxRes, ok := res.Value.(*abci.Response_CheckTx)
if !ok {
txmp.logger.Error("received incorrect type in mempool callback",
"expected", reflect.TypeOf(&abci.Response_CheckTx{}).Name(),
"got", reflect.TypeOf(res.Value).Name(),
)
return
}
tx := req.GetCheckTx().Tx
wtx := txmp.recheckCursor.Value.(*WrappedTx)
// Search through the remaining list of tx to recheck for a transaction that matches
// the one we received from the ABCI application.
for {
if bytes.Equal(tx, wtx.tx) {
// We've found a tx in the recheck list that matches the tx that we
// received from the ABCI application.
// Break, and use this transaction for further checks.
break
}
txmp.logger.Error(
"re-CheckTx transaction mismatch",
"got", wtx.tx.Hash(),
"expected", types.Tx(tx).Key(),
)
if txmp.recheckCursor == txmp.recheckEnd {
// we reached the end of the recheckTx list without finding a tx
// matching the one we received from the ABCI application.
// Return without processing any tx.
txmp.recheckCursor = nil
return
}
txmp.recheckCursor = txmp.recheckCursor.Next()
wtx = txmp.recheckCursor.Value.(*WrappedTx)
}
// Only evaluate transactions that have not been removed. This can happen
// if an existing transaction is evicted during CheckTx and while this
// callback is being executed for the same evicted transaction.
if !txmp.txStore.IsTxRemoved(wtx.hash) {
var err error
if txmp.postCheck != nil {
err = txmp.postCheck(tx, checkTxRes.CheckTx)
}
if checkTxRes.CheckTx.Code == abci.CodeTypeOK && err == nil {
wtx.priority = checkTxRes.CheckTx.Priority
} else {
txmp.logger.Debug(
"existing transaction no longer valid; failed re-CheckTx callback",
"priority", wtx.priority,
"tx", fmt.Sprintf("%X", wtx.tx.Hash()),
"err", err,
"code", checkTxRes.CheckTx.Code,
)
if wtx.gossipEl != txmp.recheckCursor {
panic("corrupted reCheckTx cursor")
}
txmp.removeTx(wtx, !txmp.config.KeepInvalidTxsInCache)
}
}
// move reCheckTx cursor to next element
if txmp.recheckCursor == txmp.recheckEnd {
txmp.recheckCursor = nil
} else {
txmp.recheckCursor = txmp.recheckCursor.Next()
}
if txmp.recheckCursor == nil {
txmp.logger.Debug("finished rechecking transactions")
if txmp.Size() > 0 {
txmp.notifyTxsAvailable()
}
}
txmp.metrics.Size.Set(float64(txmp.Size()))
}
// updateReCheckTxs updates the recheck cursors using the gossipIndex. For
// each transaction, it executes CheckTxAsync. The global callback defined on
// the proxyAppConn will be executed for each transaction after CheckTx is
// executed.
//
// NOTE:
// - The caller must have a write-lock when executing updateReCheckTxs.
func (txmp *TxMempool) updateReCheckTxs() {
if txmp.Size() == 0 {
panic("attempted to update re-CheckTx txs when mempool is empty")
}
txmp.recheckCursor = txmp.gossipIndex.Front()
txmp.recheckEnd = txmp.gossipIndex.Back()
ctx := context.Background()
for e := txmp.gossipIndex.Front(); e != nil; e = e.Next() {
wtx := e.Value.(*WrappedTx)
// Only execute CheckTx if the transaction is not marked as removed which
// could happen if the transaction was evicted.
if !txmp.txStore.IsTxRemoved(wtx.hash) {
_, err := txmp.proxyAppConn.CheckTxAsync(ctx, abci.RequestCheckTx{
Tx: wtx.tx,
Type: abci.CheckTxType_Recheck,
})
if err != nil {
// no need in retrying since the tx will be rechecked after the next block
txmp.logger.Error("failed to execute CheckTx during rechecking", "err", err)
}
}
}
if _, err := txmp.proxyAppConn.FlushAsync(ctx); err != nil {
txmp.logger.Error("failed to flush transactions during rechecking", "err", err)
}
}
// canAddTx returns an error if we cannot insert the provided *WrappedTx into
// the mempool due to mempool configured constraints. If it returns nil,
// the transaction can be inserted into the mempool.
func (txmp *TxMempool) canAddTx(wtx *WrappedTx) error {
var (
numTxs = txmp.Size()
sizeBytes = txmp.SizeBytes()
)
if numTxs >= txmp.config.Size || int64(wtx.Size())+sizeBytes > txmp.config.MaxTxsBytes {
return types.ErrMempoolIsFull{
NumTxs: numTxs,
MaxTxs: txmp.config.Size,
TxsBytes: sizeBytes,
MaxTxsBytes: txmp.config.MaxTxsBytes,
}
}
return nil
}
func (txmp *TxMempool) insertTx(wtx *WrappedTx) {
txmp.txStore.SetTx(wtx)
txmp.priorityIndex.PushTx(wtx)
txmp.heightIndex.Insert(wtx)
txmp.timestampIndex.Insert(wtx)
// Insert the transaction into the gossip index and mark the reference to the
// linked-list element, which will be needed at a later point when the
// transaction is removed.
gossipEl := txmp.gossipIndex.PushBack(wtx)
wtx.gossipEl = gossipEl
atomic.AddInt64(&txmp.sizeBytes, int64(wtx.Size()))
}
func (txmp *TxMempool) removeTx(wtx *WrappedTx, removeFromCache bool) {
if txmp.txStore.IsTxRemoved(wtx.hash) {
return
}
txmp.txStore.RemoveTx(wtx)
txmp.priorityIndex.RemoveTx(wtx)
txmp.heightIndex.Remove(wtx)
txmp.timestampIndex.Remove(wtx)
// Remove the transaction from the gossip index and cleanup the linked-list
// element so it can be garbage collected.
txmp.gossipIndex.Remove(wtx.gossipEl)
wtx.gossipEl.DetachPrev()
atomic.AddInt64(&txmp.sizeBytes, int64(-wtx.Size()))
if removeFromCache {
txmp.cache.Remove(wtx.tx)
}
}
// purgeExpiredTxs removes all transactions that have exceeded their respective
// height- and/or time-based TTLs from their respective indexes. Every expired
// transaction will be removed from the mempool, but preserved in the cache.
//
// NOTE: purgeExpiredTxs must only be called during TxMempool#Update in which
// the caller has a write-lock on the mempool and so we can safely iterate over
// the height and time based indexes.
func (txmp *TxMempool) purgeExpiredTxs(blockHeight int64) {
now := time.Now()
expiredTxs := make(map[types.TxKey]*WrappedTx)
if txmp.config.TTLNumBlocks > 0 {
purgeIdx := -1
for i, wtx := range txmp.heightIndex.txs {
if (blockHeight - wtx.height) > txmp.config.TTLNumBlocks {
expiredTxs[wtx.tx.Key()] = wtx
purgeIdx = i
} else {
// since the index is sorted, we know no other txs can be be purged
break
}
}
if purgeIdx >= 0 {
txmp.heightIndex.txs = txmp.heightIndex.txs[purgeIdx+1:]
}
}
if txmp.config.TTLDuration > 0 {
purgeIdx := -1
for i, wtx := range txmp.timestampIndex.txs {
if now.Sub(wtx.timestamp) > txmp.config.TTLDuration {
expiredTxs[wtx.tx.Key()] = wtx
purgeIdx = i
} else {
// since the index is sorted, we know no other txs can be be purged
break
}
}
if purgeIdx >= 0 {
txmp.timestampIndex.txs = txmp.timestampIndex.txs[purgeIdx+1:]
}
}
for _, wtx := range expiredTxs {
txmp.removeTx(wtx, false)
}
}
func (txmp *TxMempool) notifyTxsAvailable() {
if txmp.Size() == 0 {
panic("attempt to notify txs available but mempool is empty!")
}
if txmp.txsAvailable != nil && !txmp.notifiedTxsAvailable {
// channel cap is 1, so this will send once
txmp.notifiedTxsAvailable = true
select {
case txmp.txsAvailable <- struct{}{}:
default:
}
}
}