perf(core/txpool): pre-filter dynamic fees during pending tx retrieval #29005 (#2137)

Introduce dynamic-fee pre-filtering in txpool pending retrieval to reduce
allocations and downstream processing work during mining and tx propagation.

What changed:
- Change the `Pending` API from `Pending(enforceTips bool)` to
  `Pending(minTip *uint256.Int, baseFee *uint256.Int)` in txpool interfaces.
- Implement pre-filtering in `legacypool.Pending` by comparing effective tip
  against the provided `minTip/baseFee` for non-local, non-special txs.
- Update call sites to the new API:
  - miner work assembly (`miner/worker.go`)
  - tx sync (`eth/sync.go`)
  - pool transaction retrieval (`eth/api_backend.go`)
  - protocol/test interfaces (`eth/protocol.go`, `eth/helper_test.go`).

Tests:
- Add targeted coverage for pending filtering semantics in
  `core/txpool/legacypool/legacypool_test.go`, including:
  - minTip threshold boundary behavior
  - baseFee-aware effective tip filtering
  - local/special transaction exemption behavior
  - dynamic-fee boundary behavior when baseFee is nil.

Impact:
- Preserves existing behavior while making pending selection cheaper for
  downstream consumers.
- Improves confidence in edge-case behavior through dedicated tests.

core/txpool/legacypool/legacypool.go

@@ -577,24 +577,34 @@ func (pool *LegacyPool) ContentFrom(addr common.Address) ([]*types.Transaction,
 }
 
 // Pending retrieves all currently processable transactions, grouped by origin
-// account and sorted by nonce. The returned transaction set is a copy and can be
+// account and sorted by nonce.
-// freely modified by calling code.
 //
-// The enforceTips parameter can be used to do an extra filtering on the pending
+// The transactions can also be pre-filtered by the dynamic fee components to
-// transactions and only return those whose **effective** tip is large enough in
+// reduce allocations and load on downstream subsystems.
-// the next pending execution environment.
+func (pool *LegacyPool) Pending(minTip *uint256.Int, baseFee *uint256.Int) map[common.Address][]*txpool.LazyTransaction {
-func (pool *LegacyPool) Pending(enforceTips bool) map[common.Address][]*txpool.LazyTransaction {
 	pool.mu.Lock()
 	defer pool.mu.Unlock()
 
+	// Convert the new uint256.Int types to the old big.Int ones used by the legacy pool
+	var (
+		minTipBig  *big.Int
+		baseFeeBig *big.Int
+	)
+	if minTip != nil {
+		minTipBig = minTip.ToBig()
+	}
+	if baseFee != nil {
+		baseFeeBig = baseFee.ToBig()
+	}
+
 	pending := make(map[common.Address][]*txpool.LazyTransaction, len(pool.pending))
 	for addr, list := range pool.pending {
 		txs := list.Flatten()
 
 		// If the miner requests tip enforcement, cap the lists now
-		if enforceTips && !pool.locals.contains(addr) {
+		if minTipBig != nil && !pool.locals.contains(addr) {
 			for i, tx := range txs {
-				if !tx.IsSpecialTransaction() && tx.EffectiveGasTipIntCmp(pool.gasTip.Load().ToBig(), pool.priced.urgent.baseFee) < 0 {
+				if !tx.IsSpecialTransaction() && tx.EffectiveGasTipIntCmp(minTipBig, baseFeeBig) < 0 {
 					txs = txs[:i]
 					break
 				}

core/txpool/legacypool/legacypool_test.go

@@ -3066,6 +3066,185 @@ func BenchmarkMultiAccountBatchInsert(b *testing.B) {
 	}
 }
 
+func TestPendingMinTipThreshold(t *testing.T) {
+	t.Parallel()
+
+	pool, key := setupPool()
+	defer pool.Close()
+
+	addr := crypto.PubkeyToAddress(key.PublicKey)
+	testAddBalance(pool, addr, big.NewInt(1_000_000_000_000_000))
+	threshold := new(big.Int).Add(new(big.Int).Set(common.MinGasPrice), big.NewInt(100))
+	aboveThreshold := new(big.Int).Set(threshold)
+	belowThreshold := new(big.Int).Sub(new(big.Int).Set(threshold), big.NewInt(1))
+
+	if err := pool.addRemoteSync(pricedTransaction(0, 100000, aboveThreshold, key)); err != nil {
+		t.Fatalf("failed to add tx nonce 0: %v", err)
+	}
+	if err := pool.addRemoteSync(pricedTransaction(1, 100000, belowThreshold, key)); err != nil {
+		t.Fatalf("failed to add tx nonce 1: %v", err)
+	}
+
+	filtered := pool.Pending(uint256.MustFromBig(threshold), nil)
+	txs := filtered[addr]
+	if len(txs) != 1 {
+		t.Fatalf("unexpected filtered tx count: have %d, want %d", len(txs), 1)
+	}
+	resolved := txs[0].Resolve()
+	if resolved == nil || resolved.Nonce() != 0 {
+		have := uint64(math.MaxUint64)
+		if resolved != nil {
+			have = resolved.Nonce()
+		}
+		t.Fatalf("unexpected surviving tx after tip filter: got nonce %d", have)
+	}
+
+	all := pool.Pending(nil, nil)
+	if len(all[addr]) != 2 {
+		t.Fatalf("unexpected unfiltered tx count: have %d, want %d", len(all[addr]), 2)
+	}
+}
+
+func TestPendingMinTipWithBaseFee(t *testing.T) {
+	t.Parallel()
+
+	pool, key := setupPoolWithConfig(eip1559Config)
+	defer pool.Close()
+
+	addr := crypto.PubkeyToAddress(key.PublicKey)
+	testAddBalance(pool, addr, big.NewInt(1_000_000_000_000_000))
+	minGasTip := new(big.Int).Set(common.MinGasPrice)
+	tipPass := new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(80))
+	tipPassWithoutBaseFeeOnly := new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(60))
+
+	if err := pool.addRemoteSync(dynamicFeeTx(0, 100000, new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(300)), tipPass, key)); err != nil {
+		t.Fatalf("failed to add tx nonce 0: %v", err)
+	}
+	if err := pool.addRemoteSync(dynamicFeeTx(1, 100000, new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(240)), tipPassWithoutBaseFeeOnly, key)); err != nil {
+		t.Fatalf("failed to add tx nonce 1: %v", err)
+	}
+	if err := pool.addRemoteSync(dynamicFeeTx(2, 100000, new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(240)), tipPassWithoutBaseFeeOnly, key)); err != nil {
+		t.Fatalf("failed to add tx nonce 2: %v", err)
+	}
+
+	minTipBig := new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(45))
+	baseFeeBig := big.NewInt(200)
+	minTip := uint256.MustFromBig(minTipBig)
+	baseFee := uint256.MustFromBig(baseFeeBig)
+
+	withBaseFee := pool.Pending(minTip, baseFee)
+	txs := withBaseFee[addr]
+	if len(txs) != 1 {
+		t.Fatalf("unexpected tx count with base fee filter: have %d, want %d", len(txs), 1)
+	}
+	resolved := txs[0].Resolve()
+	if resolved == nil || resolved.Nonce() != 0 {
+		have := uint64(math.MaxUint64)
+		if resolved != nil {
+			have = resolved.Nonce()
+		}
+		t.Fatalf("unexpected surviving tx with base fee filter: got nonce %d", have)
+	}
+
+	withoutBaseFee := pool.Pending(minTip, nil)
+	if len(withoutBaseFee[addr]) != 3 {
+		t.Fatalf("unexpected tx count without base fee filter: have %d, want %d", len(withoutBaseFee[addr]), 3)
+	}
+}
+
+func TestPendingKeepsLocalAndSpecialTransactions(t *testing.T) {
+	t.Parallel()
+
+	pool, _ := setupPool()
+	defer pool.Close()
+	minGasTip := new(big.Int).Set(common.MinGasPrice)
+	filterTip := new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(100))
+
+	specialKey, _ := crypto.GenerateKey()
+	specialAddr := crypto.PubkeyToAddress(specialKey.PublicKey)
+	testAddBalance(pool, specialAddr, big.NewInt(1_000_000_000_000_000))
+
+	specialTx, _ := types.SignTx(types.NewTransaction(0, common.BlockSignersBinary, big.NewInt(1), 100000, new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(1)), nil), types.HomesteadSigner{}, specialKey)
+	if err := pool.addRemoteSync(specialTx); err != nil {
+		t.Fatalf("failed to add special tx: %v", err)
+	}
+	normalTx := pricedTransaction(1, 100000, new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(200)), specialKey)
+	if err := pool.addRemoteSync(normalTx); err != nil {
+		t.Fatalf("failed to add normal tx after special tx: %v", err)
+	}
+
+	localKey, _ := crypto.GenerateKey()
+	localAddr := crypto.PubkeyToAddress(localKey.PublicKey)
+	testAddBalance(pool, localAddr, big.NewInt(1_000_000_000_000_000))
+	if err := pool.addLocal(pricedTransaction(0, 100000, new(big.Int).Add(new(big.Int).Set(minGasTip), big.NewInt(1)), localKey)); err != nil {
+		t.Fatalf("failed to add local tx: %v", err)
+	}
+
+	filtered := pool.Pending(uint256.MustFromBig(filterTip), nil)
+
+	specialPending := filtered[specialAddr]
+	if len(specialPending) != 2 {
+		t.Fatalf("unexpected special account tx count: have %d, want %d", len(specialPending), 2)
+	}
+	first := specialPending[0].Resolve()
+	if first == nil || first.Nonce() != 0 || !first.IsSpecialTransaction() {
+		t.Fatalf("special tx should survive filtering at nonce 0")
+	}
+	second := specialPending[1].Resolve()
+	if second == nil || second.Nonce() != 1 {
+		t.Fatalf("unexpected tx order for special account")
+	}
+
+	localPending := filtered[localAddr]
+	if len(localPending) != 1 {
+		t.Fatalf("unexpected local account tx count: have %d, want %d", len(localPending), 1)
+	}
+	local := localPending[0].Resolve()
+	if local == nil || local.Nonce() != 0 {
+		t.Fatalf("unexpected local tx after filtering")
+	}
+}
+
+func TestPendingDynamicFeeThresholdWithoutBaseFee(t *testing.T) {
+	t.Parallel()
+
+	pool, key := setupPoolWithConfig(eip1559Config)
+	defer pool.Close()
+
+	addr := crypto.PubkeyToAddress(key.PublicKey)
+	testAddBalance(pool, addr, big.NewInt(1_000_000_000_000_000))
+
+	minTipBig := new(big.Int).Add(new(big.Int).Set(common.MinGasPrice), big.NewInt(50))
+	equalTip := new(big.Int).Set(minTipBig)
+	belowTip := new(big.Int).Sub(new(big.Int).Set(minTipBig), big.NewInt(1))
+
+	if err := pool.addRemoteSync(dynamicFeeTx(0, 100000, new(big.Int).Add(new(big.Int).Set(equalTip), big.NewInt(100)), equalTip, key)); err != nil {
+		t.Fatalf("failed to add tx nonce 0: %v", err)
+	}
+	if err := pool.addRemoteSync(dynamicFeeTx(1, 100000, new(big.Int).Add(new(big.Int).Set(equalTip), big.NewInt(100)), belowTip, key)); err != nil {
+		t.Fatalf("failed to add tx nonce 1: %v", err)
+	}
+
+	filtered := pool.Pending(uint256.MustFromBig(minTipBig), nil)
+	txs := filtered[addr]
+	if len(txs) != 1 {
+		t.Fatalf("unexpected filtered tx count: have %d, want %d", len(txs), 1)
+	}
+	resolved := txs[0].Resolve()
+	if resolved == nil || resolved.Nonce() != 0 {
+		have := uint64(math.MaxUint64)
+		if resolved != nil {
+			have = resolved.Nonce()
+		}
+		t.Fatalf("unexpected surviving tx without base fee: got nonce %d", have)
+	}
+
+	all := pool.Pending(nil, nil)
+	if len(all[addr]) != 2 {
+		t.Fatalf("unexpected unfiltered tx count: have %d, want %d", len(all[addr]), 2)
+	}
+}
+
 // TestSetGasPrice tests the SetGasPrice validation logic using table-driven tests
 func TestSetGasPrice(t *testing.T) {
 	testCases := []struct {

core/txpool/subpool.go

@@ -24,6 +24,7 @@ import (
 	"github.com/XinFinOrg/XDPoSChain/core"
 	"github.com/XinFinOrg/XDPoSChain/core/types"
 	"github.com/XinFinOrg/XDPoSChain/event"
+	"github.com/holiman/uint256"
 )
 
 // LazyTransaction contains a small subset of the transaction properties that is
@@ -109,7 +110,10 @@ type SubPool interface {
 
 	// Pending retrieves all currently processable transactions, grouped by origin
 	// account and sorted by nonce.
-	Pending(enforceTips bool) map[common.Address][]*LazyTransaction
+	//
+	// The transactions can also be pre-filtered by the dynamic fee components to
+	// reduce allocations and load on downstream subsystems.
+	Pending(minTip *uint256.Int, baseFee *uint256.Int) map[common.Address][]*LazyTransaction
 
 	// SubscribeTransactions subscribes to new transaction events. The subscriber
 	// can decide whether to receive notifications only for newly seen transactions

core/txpool/txpool.go

@@ -25,6 +25,7 @@ import (
 	"github.com/XinFinOrg/XDPoSChain/core"
 	"github.com/XinFinOrg/XDPoSChain/core/types"
 	"github.com/XinFinOrg/XDPoSChain/event"
+	"github.com/holiman/uint256"
 )
 
 // TxStatus is the current status of a transaction as seen by the pool.
@@ -250,10 +251,13 @@ func (p *TxPool) Add(txs []*types.Transaction, local bool, sync bool) []error {
 
 // Pending retrieves all currently processable transactions, grouped by origin
 // account and sorted by nonce.
-func (p *TxPool) Pending(enforceTips bool) map[common.Address][]*LazyTransaction {
+//
+// The transactions can also be pre-filtered by the dynamic fee components to
+// reduce allocations and load on downstream subsystems.
+func (p *TxPool) Pending(minTip *uint256.Int, baseFee *uint256.Int) map[common.Address][]*LazyTransaction {
 	txs := make(map[common.Address][]*LazyTransaction)
 	for _, subpool := range p.subpools {
-		maps.Copy(txs, subpool.Pending(enforceTips))
+		maps.Copy(txs, subpool.Pending(minTip, baseFee))
 	}
 	return txs
 }

eth/api_backend.go

@@ -305,7 +305,7 @@ func (b *EthAPIBackend) SendTx(ctx context.Context, signedTx *types.Transaction)
 }
 
 func (b *EthAPIBackend) GetPoolTransactions() (types.Transactions, error) {
-	pending := b.eth.txPool.Pending(false)
+	pending := b.eth.txPool.Pending(nil, nil)
 	var txs types.Transactions
 	for _, batch := range pending {
 		for _, lazy := range batch {

eth/helper_test.go

@@ -42,6 +42,7 @@ import (
 	"github.com/XinFinOrg/XDPoSChain/p2p"
 	"github.com/XinFinOrg/XDPoSChain/p2p/discover"
 	"github.com/XinFinOrg/XDPoSChain/params"
+	"github.com/holiman/uint256"
 )
 
 var (
@@ -146,7 +147,7 @@ func (p *testTxPool) Add(txs []*types.Transaction, local bool, sync bool) []erro
 }
 
 // Pending returns all the transactions known to the pool
-func (p *testTxPool) Pending(enforceTips bool) map[common.Address][]*txpool.LazyTransaction {
+func (p *testTxPool) Pending(minTip *uint256.Int, baseFee *uint256.Int) map[common.Address][]*txpool.LazyTransaction {
 	p.lock.RLock()
 	defer p.lock.RUnlock()
 

eth/protocol.go

@@ -27,6 +27,7 @@ import (
 	"github.com/XinFinOrg/XDPoSChain/core/types"
 	"github.com/XinFinOrg/XDPoSChain/event"
 	"github.com/XinFinOrg/XDPoSChain/rlp"
+	"github.com/holiman/uint256"
 )
 
 // Constants to match up protocol versions and messages
@@ -109,7 +110,7 @@ type txPool interface {
 
 	// Pending should return pending transactions.
 	// The slice should be modifiable by the caller.
-	Pending(enforceTips bool) map[common.Address][]*txpool.LazyTransaction
+	Pending(minTip *uint256.Int, baseFee *uint256.Int) map[common.Address][]*txpool.LazyTransaction
 
 	// SubscribeTransactions subscribes to new transaction events. The subscriber
 	// can decide whether to receive notifications only for newly seen transactions

eth/sync.go

@@ -45,7 +45,7 @@ type txsync struct {
 // syncTransactions starts sending all currently pending transactions to the given peer.
 func (pm *ProtocolManager) syncTransactions(p *peer) {
 	var txs types.Transactions
-	pending := pm.txpool.Pending(false)
+	pending := pm.txpool.Pending(nil, nil)
 	for _, batch := range pending {
 		for _, lazy := range batch {
 			if tx := lazy.Resolve(); tx != nil {

miner/worker.go

@@ -46,6 +46,7 @@ import (
 	"github.com/XinFinOrg/XDPoSChain/params"
 	"github.com/XinFinOrg/XDPoSChain/trie"
 	mapset "github.com/deckarep/golang-set/v2"
+	"github.com/holiman/uint256"
 )
 
 const (
@@ -860,7 +861,12 @@ func (w *worker) commitNewWork() {
 			log.Error("[commitNewWork] fail to check if block is epoch switch block when fetching pending transactions", "BlockNum", header.Number, "Hash", header.Hash())
 		}
 		if !isEpochSwitchBlock {
-			pending := w.eth.TxPool().Pending(true)
+			// Retrieve the pending transactions pre-filtered by the 1559 dynamic fees
+			var baseFee *uint256.Int
+			if header.BaseFee != nil {
+				baseFee = uint256.MustFromBig(header.BaseFee)
+			}
+			pending := w.eth.TxPool().Pending(uint256.MustFromBig(w.tip), baseFee)
 			txs, specialTxs = newTransactionsByPriceAndNonce(w.current.signer, pending, feeCapacity, header.BaseFee)
 		}
 	}