core/txpool: use slots to check queued, pending transactions limit

Since commit 8bd37a1d91 (core: count tx size in slots, bump max size ot
4x32KB), txpool uses transaction slot for transaction accounting. However, when
truncating queued and pending transactions, we still use number of transactions.
This commit change all the places to consistently use transaction slot.

core/txpool/legacypool/legacypool.go

@@ -1489,25 +1489,48 @@ func (pool *LegacyPool) promoteExecutables(accounts []common.Address) []*types.T
 	return promoted
 }
 
+// removeLastPendingTransaction removes the highest nonce transaction of the sender from
+// the pending transactions, returns the number of transaction slot of that transaction
+func (pool *LegacyPool) removeLastPendingTransaction(sender common.Address) uint64 {
+	list := pool.pending[sender]
+
+	// Remove the transaction with highest nonce
+	lastTx := list.LastElement()
+	list.Remove(lastTx)
+
+	// Drop the transaction from the global pools too
+	pool.all.Remove(lastTx.Hash())
+	// Update the account nonce to the dropped transaction
+	pool.pendingNonces.setIfLower(sender, lastTx.Nonce())
+	log.Trace("Removed fairness-exceeding pending transaction", "hash", lastTx.Hash())
+
+	pool.priced.Removed(1)
+	pendingGauge.Dec(1)
+	if pool.locals.contains(sender) {
+		localGauge.Dec(1)
+	}
+	return uint64(numSlots(lastTx))
+}
+
 // truncatePending removes transactions from the pending queue if the pool is above the
 // pending limit. The algorithm tries to reduce transaction counts by an approximately
 // equal number for all for accounts with many pending transactions.
 func (pool *LegacyPool) truncatePending() {
 	pending := uint64(0)
+	droppedTxs := 0
 	for _, list := range pool.pending {
-		pending += uint64(list.Len())
+		pending += uint64(list.TotalSlots())
 	}
 	if pending <= pool.config.GlobalSlots {
 		return
 	}
 
-	pendingBeforeCap := pending
 	// Assemble a spam order to penalize large transactors first
 	spammers := prque.New[int64, common.Address](nil)
 	for addr, list := range pool.pending {
 		// Only evict transactions from high rollers
-		if !pool.locals.contains(addr) && uint64(list.Len()) > pool.config.AccountSlots {
-			spammers.Push(addr, int64(list.Len()))
+		if !pool.locals.contains(addr) && uint64(list.TotalSlots()) > pool.config.AccountSlots {
+			spammers.Push(addr, int64(list.TotalSlots()))
 		}
 	}
 	// Gradually drop transactions from offenders
@@ -1520,29 +1543,23 @@ func (pool *LegacyPool) truncatePending() {
 		// 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].Len()
+			threshold := pool.pending[offender].TotalSlots()
 
 			// Iteratively reduce all offenders until below limit or threshold reached
-			for pending > pool.config.GlobalSlots && pool.pending[offenders[len(offenders)-2]].Len() > threshold {
+			for pending > pool.config.GlobalSlots {
+				lowerThanThreshold := 0
 				for i := 0; i < len(offenders)-1; i++ {
-					list := pool.pending[offenders[i]]
-
-					caps := list.Cap(list.Len() - 1)
-					for _, tx := range caps {
-						// Drop the transaction from the global pools too
-						hash := tx.Hash()
-						pool.all.Remove(hash)
-
-						// Update the account nonce to the dropped transaction
-						pool.pendingNonces.setIfLower(offenders[i], tx.Nonce())
-						log.Trace("Removed fairness-exceeding pending transaction", "hash", hash)
+					if pool.pending[offenders[i]].TotalSlots() <= threshold {
+						lowerThanThreshold++
+						continue
 					}
-					pool.priced.Removed(len(caps))
-					pendingGauge.Dec(int64(len(caps)))
-					if pool.locals.contains(offenders[i]) {
-						localGauge.Dec(int64(len(caps)))
+
+					pending -= pool.removeLastPendingTransaction(offenders[i])
+					droppedTxs++
 				}
-					pending--
+
+				if lowerThanThreshold == len(offenders)-1 {
+					break
 				}
 			}
 		}
@@ -1550,37 +1567,30 @@ func (pool *LegacyPool) truncatePending() {
 
 	// If still above threshold, reduce to limit or min allowance
 	if pending > pool.config.GlobalSlots && len(offenders) > 0 {
-		for pending > pool.config.GlobalSlots && uint64(pool.pending[offenders[len(offenders)-1]].Len()) > pool.config.AccountSlots {
+		for pending > pool.config.GlobalSlots {
+			lowerThanThreshold := 0
 			for _, addr := range offenders {
-				list := pool.pending[addr]
+				if uint64(pool.pending[addr].TotalSlots()) <= pool.config.AccountSlots {
+					lowerThanThreshold++
+					continue
+				}
+				pending -= pool.removeLastPendingTransaction(addr)
+				droppedTxs++
+			}
 
-				caps := list.Cap(list.Len() - 1)
-				for _, tx := range caps {
-					// Drop the transaction from the global pools too
-					hash := tx.Hash()
-					pool.all.Remove(hash)
-
-					// Update the account nonce to the dropped transaction
-					pool.pendingNonces.setIfLower(addr, tx.Nonce())
-					log.Trace("Removed fairness-exceeding pending transaction", "hash", hash)
-				}
-				pool.priced.Removed(len(caps))
-				pendingGauge.Dec(int64(len(caps)))
-				if pool.locals.contains(addr) {
-					localGauge.Dec(int64(len(caps)))
-				}
-				pending--
+			if lowerThanThreshold == len(offenders) {
+				break
 			}
 		}
 	}
-	pendingRateLimitMeter.Mark(int64(pendingBeforeCap - pending))
+	pendingRateLimitMeter.Mark(int64(droppedTxs))
 }
 
 // truncateQueue drops the oldest transactions in the queue if the pool is above the global queue limit.
 func (pool *LegacyPool) truncateQueue() {
 	queued := uint64(0)
 	for _, list := range pool.queue {
-		queued += uint64(list.Len())
+		queued += uint64(list.TotalSlots())
 	}
 	if queued <= pool.config.GlobalQueue {
 		return
@@ -1596,26 +1606,26 @@ func (pool *LegacyPool) truncateQueue() {
 	sort.Sort(sort.Reverse(addresses))
 
 	// Drop transactions until the total is below the limit or only locals remain
-	for drop := queued - pool.config.GlobalQueue; drop > 0 && len(addresses) > 0; {
+	for drop := int(queued - pool.config.GlobalQueue); drop > 0 && len(addresses) > 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 {
+		if list.TotalSlots() <= drop {
 			for _, tx := range list.Flatten() {
 				pool.removeTx(tx.Hash(), true, true)
 			}
-			drop -= size
-			queuedRateLimitMeter.Mark(int64(size))
+			drop -= list.TotalSlots()
+			queuedRateLimitMeter.Mark(int64(list.Len()))
 			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(), true, true)
-			drop--
+			drop -= numSlots(txs[i])
 			queuedRateLimitMeter.Mark(1)
 		}
 	}

core/txpool/legacypool/list.go

@@ -157,22 +157,26 @@ func (m *sortedMap) filter(filter func(*types.Transaction) bool) types.Transacti
 	return removed
 }
 
-// Cap places a hard limit on the number of items, returning all transactions
+// Cap places a hard limit on the total slots of items, returning all transactions
 // exceeding that limit.
 func (m *sortedMap) Cap(threshold int) types.Transactions {
 	// Short circuit if the number of items is under the limit
-	if len(m.items) <= threshold {
+	if m.totalslots <= threshold {
 		return nil
 	}
 	// Otherwise gather and drop the highest nonce'd transactions
-	var drops types.Transactions
+	var (
+		drops types.Transactions
+		size  int
+	)
 
 	sort.Sort(*m.index)
-	for size := len(m.items); size > threshold; size-- {
+	for size = len(m.items); m.totalslots > threshold; size-- {
 		drops = append(drops, m.items[(*m.index)[size-1]])
+		m.totalslots -= numSlots(m.items[(*m.index)[size-1]])
 		delete(m.items, (*m.index)[size-1])
 	}
-	*m.index = (*m.index)[:threshold]
+	*m.index = (*m.index)[:size]
 	heap.Init(m.index)
 
 	// If we had a cache, shift the back