mirror of
https://github.com/nspcc-dev/neo-go.git
synced 2024-12-29 19:27:36 +00:00
319 lines
9.6 KiB
Go
319 lines
9.6 KiB
Go
package mempool
|
|
|
|
import (
|
|
"errors"
|
|
"math/big"
|
|
"sort"
|
|
"sync"
|
|
|
|
"github.com/nspcc-dev/neo-go/pkg/core/transaction"
|
|
"github.com/nspcc-dev/neo-go/pkg/util"
|
|
)
|
|
|
|
var (
|
|
// ErrInsufficientFunds is returned when Sender is not able to pay for
|
|
// transaction being added irrespective of the other contents of the
|
|
// pool.
|
|
ErrInsufficientFunds = errors.New("insufficient funds")
|
|
// ErrConflict is returned when transaction being added is incompatible
|
|
// with the contents of the memory pool (Sender doesn't have enough GAS
|
|
// to pay for all transactions in the pool).
|
|
ErrConflict = errors.New("conflicts with the memory pool")
|
|
// ErrDup is returned when transaction being added is already present
|
|
// in the memory pool.
|
|
ErrDup = errors.New("already in the memory pool")
|
|
// ErrOOM is returned when transaction just doesn't fit in the memory
|
|
// pool because of its capacity constraints.
|
|
ErrOOM = errors.New("out of memory")
|
|
)
|
|
|
|
// item represents a transaction in the the Memory pool.
|
|
type item struct {
|
|
txn *transaction.Transaction
|
|
blockStamp uint32
|
|
}
|
|
|
|
// items is a slice of item.
|
|
type items []item
|
|
|
|
// utilityBalanceAndFees stores sender's balance and overall fees of
|
|
// sender's transactions which are currently in mempool
|
|
type utilityBalanceAndFees struct {
|
|
balance *big.Int
|
|
feeSum *big.Int
|
|
}
|
|
|
|
// Pool stores the unconfirms transactions.
|
|
type Pool struct {
|
|
lock sync.RWMutex
|
|
verifiedMap map[util.Uint256]*transaction.Transaction
|
|
verifiedTxes items
|
|
fees map[util.Uint160]utilityBalanceAndFees
|
|
|
|
capacity int
|
|
feePerByte int64
|
|
}
|
|
|
|
func (p items) Len() int { return len(p) }
|
|
func (p items) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
|
|
func (p items) Less(i, j int) bool { return p[i].CompareTo(p[j]) < 0 }
|
|
|
|
// CompareTo returns the difference between two items.
|
|
// difference < 0 implies p < otherP.
|
|
// difference = 0 implies p = otherP.
|
|
// difference > 0 implies p > otherP.
|
|
func (p item) CompareTo(otherP item) int {
|
|
pHigh := p.txn.HasAttribute(transaction.HighPriority)
|
|
otherHigh := otherP.txn.HasAttribute(transaction.HighPriority)
|
|
if pHigh && !otherHigh {
|
|
return 1
|
|
} else if !pHigh && otherHigh {
|
|
return -1
|
|
}
|
|
|
|
// Fees sorted ascending.
|
|
if ret := int(p.txn.FeePerByte() - otherP.txn.FeePerByte()); ret != 0 {
|
|
return ret
|
|
}
|
|
|
|
return int(p.txn.NetworkFee - otherP.txn.NetworkFee)
|
|
}
|
|
|
|
// Count returns the total number of uncofirm transactions.
|
|
func (mp *Pool) Count() int {
|
|
mp.lock.RLock()
|
|
defer mp.lock.RUnlock()
|
|
return mp.count()
|
|
}
|
|
|
|
// count is an internal unlocked version of Count.
|
|
func (mp *Pool) count() int {
|
|
return len(mp.verifiedTxes)
|
|
}
|
|
|
|
// ContainsKey checks if a transactions hash is in the Pool.
|
|
func (mp *Pool) ContainsKey(hash util.Uint256) bool {
|
|
mp.lock.RLock()
|
|
defer mp.lock.RUnlock()
|
|
|
|
return mp.containsKey(hash)
|
|
}
|
|
|
|
// containsKey is an internal unlocked version of ContainsKey.
|
|
func (mp *Pool) containsKey(hash util.Uint256) bool {
|
|
if _, ok := mp.verifiedMap[hash]; ok {
|
|
return true
|
|
}
|
|
|
|
return false
|
|
}
|
|
|
|
// tryAddSendersFee tries to add system fee and network fee to the total sender`s fee in mempool
|
|
// and returns false if both balance check is required and sender has not enough GAS to pay
|
|
func (mp *Pool) tryAddSendersFee(tx *transaction.Transaction, feer Feer, needCheck bool) bool {
|
|
senderFee, ok := mp.fees[tx.Sender()]
|
|
if !ok {
|
|
senderFee.balance = feer.GetUtilityTokenBalance(tx.Sender())
|
|
senderFee.feeSum = big.NewInt(0)
|
|
mp.fees[tx.Sender()] = senderFee
|
|
}
|
|
if needCheck {
|
|
newFeeSum, err := checkBalance(tx, senderFee)
|
|
if err != nil {
|
|
return false
|
|
}
|
|
senderFee.feeSum.Set(newFeeSum)
|
|
} else {
|
|
senderFee.feeSum.Add(senderFee.feeSum, big.NewInt(tx.SystemFee+tx.NetworkFee))
|
|
}
|
|
return true
|
|
}
|
|
|
|
// checkBalance returns new cumulative fee balance for account or an error in
|
|
// case sender doesn't have enough GAS to pay for the transaction.
|
|
func checkBalance(tx *transaction.Transaction, balance utilityBalanceAndFees) (*big.Int, error) {
|
|
txFee := big.NewInt(tx.SystemFee + tx.NetworkFee)
|
|
if balance.balance.Cmp(txFee) < 0 {
|
|
return nil, ErrInsufficientFunds
|
|
}
|
|
txFee.Add(txFee, balance.feeSum)
|
|
if balance.balance.Cmp(txFee) < 0 {
|
|
return nil, ErrConflict
|
|
}
|
|
return txFee, nil
|
|
}
|
|
|
|
// Add tries to add given transaction to the Pool.
|
|
func (mp *Pool) Add(t *transaction.Transaction, fee Feer) error {
|
|
var pItem = item{
|
|
txn: t,
|
|
blockStamp: fee.BlockHeight(),
|
|
}
|
|
mp.lock.Lock()
|
|
if mp.containsKey(t.Hash()) {
|
|
mp.lock.Unlock()
|
|
return ErrDup
|
|
}
|
|
err := mp.checkTxConflicts(t, fee)
|
|
if err != nil {
|
|
mp.lock.Unlock()
|
|
return err
|
|
}
|
|
|
|
mp.verifiedMap[t.Hash()] = t
|
|
// Insert into sorted array (from max to min, that could also be done
|
|
// using sort.Sort(sort.Reverse()), but it incurs more overhead. Notice
|
|
// also that we're searching for position that is strictly more
|
|
// prioritized than our new item because we do expect a lot of
|
|
// transactions with the same priority and appending to the end of the
|
|
// slice is always more efficient.
|
|
n := sort.Search(len(mp.verifiedTxes), func(n int) bool {
|
|
return pItem.CompareTo(mp.verifiedTxes[n]) > 0
|
|
})
|
|
|
|
// We've reached our capacity already.
|
|
if len(mp.verifiedTxes) == mp.capacity {
|
|
// Less prioritized than the least prioritized we already have, won't fit.
|
|
if n == len(mp.verifiedTxes) {
|
|
mp.lock.Unlock()
|
|
return ErrOOM
|
|
}
|
|
// Ditch the last one.
|
|
unlucky := mp.verifiedTxes[len(mp.verifiedTxes)-1]
|
|
delete(mp.verifiedMap, unlucky.txn.Hash())
|
|
mp.verifiedTxes[len(mp.verifiedTxes)-1] = pItem
|
|
} else {
|
|
mp.verifiedTxes = append(mp.verifiedTxes, pItem)
|
|
}
|
|
if n != len(mp.verifiedTxes)-1 {
|
|
copy(mp.verifiedTxes[n+1:], mp.verifiedTxes[n:])
|
|
mp.verifiedTxes[n] = pItem
|
|
}
|
|
// we already checked balance in checkTxConflicts, so don't need to check again
|
|
mp.tryAddSendersFee(pItem.txn, fee, false)
|
|
|
|
updateMempoolMetrics(len(mp.verifiedTxes))
|
|
mp.lock.Unlock()
|
|
return nil
|
|
}
|
|
|
|
// Remove removes an item from the mempool, if it exists there (and does
|
|
// nothing if it doesn't).
|
|
func (mp *Pool) Remove(hash util.Uint256) {
|
|
mp.lock.Lock()
|
|
if tx, ok := mp.verifiedMap[hash]; ok {
|
|
var num int
|
|
delete(mp.verifiedMap, hash)
|
|
for num = range mp.verifiedTxes {
|
|
if hash.Equals(mp.verifiedTxes[num].txn.Hash()) {
|
|
break
|
|
}
|
|
}
|
|
if num < len(mp.verifiedTxes)-1 {
|
|
mp.verifiedTxes = append(mp.verifiedTxes[:num], mp.verifiedTxes[num+1:]...)
|
|
} else if num == len(mp.verifiedTxes)-1 {
|
|
mp.verifiedTxes = mp.verifiedTxes[:num]
|
|
}
|
|
senderFee := mp.fees[tx.Sender()]
|
|
senderFee.feeSum.Sub(senderFee.feeSum, big.NewInt(tx.SystemFee+tx.NetworkFee))
|
|
mp.fees[tx.Sender()] = senderFee
|
|
}
|
|
updateMempoolMetrics(len(mp.verifiedTxes))
|
|
mp.lock.Unlock()
|
|
}
|
|
|
|
// RemoveStale filters verified transactions through the given function keeping
|
|
// only the transactions for which it returns a true result. It's used to quickly
|
|
// drop part of the mempool that is now invalid after the block acceptance.
|
|
func (mp *Pool) RemoveStale(isOK func(*transaction.Transaction) bool, feer Feer) {
|
|
mp.lock.Lock()
|
|
policyChanged := mp.loadPolicy(feer)
|
|
// We can reuse already allocated slice
|
|
// because items are iterated one-by-one in increasing order.
|
|
newVerifiedTxes := mp.verifiedTxes[:0]
|
|
mp.fees = make(map[util.Uint160]utilityBalanceAndFees) // it'd be nice to reuse existing map, but we can't easily clear it
|
|
for _, itm := range mp.verifiedTxes {
|
|
if isOK(itm.txn) && mp.checkPolicy(itm.txn, policyChanged) && mp.tryAddSendersFee(itm.txn, feer, true) {
|
|
newVerifiedTxes = append(newVerifiedTxes, itm)
|
|
} else {
|
|
delete(mp.verifiedMap, itm.txn.Hash())
|
|
}
|
|
}
|
|
mp.verifiedTxes = newVerifiedTxes
|
|
mp.lock.Unlock()
|
|
}
|
|
|
|
// loadPolicy updates feePerByte field and returns whether policy has been
|
|
// changed.
|
|
func (mp *Pool) loadPolicy(feer Feer) bool {
|
|
newFeePerByte := feer.FeePerByte()
|
|
if newFeePerByte > mp.feePerByte {
|
|
mp.feePerByte = newFeePerByte
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
// checkPolicy checks whether transaction fits policy.
|
|
func (mp *Pool) checkPolicy(tx *transaction.Transaction, policyChanged bool) bool {
|
|
if !policyChanged || tx.FeePerByte() >= mp.feePerByte {
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
// New returns a new Pool struct.
|
|
func New(capacity int) *Pool {
|
|
return &Pool{
|
|
verifiedMap: make(map[util.Uint256]*transaction.Transaction),
|
|
verifiedTxes: make([]item, 0, capacity),
|
|
capacity: capacity,
|
|
fees: make(map[util.Uint160]utilityBalanceAndFees),
|
|
}
|
|
}
|
|
|
|
// TryGetValue returns a transaction and its fee if it exists in the memory pool.
|
|
func (mp *Pool) TryGetValue(hash util.Uint256) (*transaction.Transaction, bool) {
|
|
mp.lock.RLock()
|
|
defer mp.lock.RUnlock()
|
|
if tx, ok := mp.verifiedMap[hash]; ok {
|
|
return tx, ok
|
|
}
|
|
|
|
return nil, false
|
|
}
|
|
|
|
// GetVerifiedTransactions returns a slice of transactions with their fees.
|
|
func (mp *Pool) GetVerifiedTransactions() []*transaction.Transaction {
|
|
mp.lock.RLock()
|
|
defer mp.lock.RUnlock()
|
|
|
|
var t = make([]*transaction.Transaction, len(mp.verifiedTxes))
|
|
|
|
for i := range mp.verifiedTxes {
|
|
t[i] = mp.verifiedTxes[i].txn
|
|
}
|
|
|
|
return t
|
|
}
|
|
|
|
// checkTxConflicts is an internal unprotected version of Verify.
|
|
func (mp *Pool) checkTxConflicts(tx *transaction.Transaction, fee Feer) error {
|
|
senderFee, ok := mp.fees[tx.Sender()]
|
|
if !ok {
|
|
senderFee.balance = fee.GetUtilityTokenBalance(tx.Sender())
|
|
senderFee.feeSum = big.NewInt(0)
|
|
}
|
|
_, err := checkBalance(tx, senderFee)
|
|
return err
|
|
}
|
|
|
|
// Verify checks if a Sender of tx is able to pay for it (and all the other
|
|
// transactions in the pool). If yes, the transaction tx is a valid
|
|
// transaction and the function returns true. If no, the transaction tx is
|
|
// considered to be invalid the function returns false.
|
|
func (mp *Pool) Verify(tx *transaction.Transaction, feer Feer) bool {
|
|
mp.lock.RLock()
|
|
defer mp.lock.RUnlock()
|
|
return mp.checkTxConflicts(tx, feer) == nil
|
|
}
|