core/types: Add allocation-free EffectiveGasTipInto method

core/types/transaction.go

@@ -355,28 +355,37 @@ func (tx *Transaction) GasTipCapIntCmp(other *big.Int) int {
 // Note: if the effective gasTipCap is negative, this method returns both error
 // the actual negative value, _and_ ErrGasFeeCapTooLow
 func (tx *Transaction) EffectiveGasTip(baseFee *big.Int) (*big.Int, error) {
+	dst := new(big.Int)
+	err := tx.EffectiveGasTipInto(dst, baseFee)
+	return dst, err
+}
+
+func (tx *Transaction) EffectiveGasTipInto(dst *big.Int, baseFee *big.Int) error {
 	if baseFee == nil {
-		return tx.GasTipCap(), nil
+		dst.Set(tx.inner.gasTipCap())
+		return nil
 	}
+
 	var err error
-	gasFeeCap := tx.GasFeeCap()
+	gasFeeCap := tx.inner.gasFeeCap()
 	if gasFeeCap.Cmp(baseFee) < 0 {
 		err = ErrGasFeeCapTooLow
 	}
-	gasFeeCap = gasFeeCap.Sub(gasFeeCap, baseFee)
 
-	gasTipCap := tx.GasTipCap()
-	if gasTipCap.Cmp(gasFeeCap) < 0 {
-		return gasTipCap, err
+	dst.Sub(gasFeeCap, baseFee)
+	gasTipCap := tx.inner.gasTipCap()
+	if gasTipCap.Cmp(dst) < 0 {
+		dst.Set(gasTipCap)
 	}
-	return gasFeeCap, err
+	return err
 }
 
 // EffectiveGasTipValue is identical to EffectiveGasTip, but does not return an
 // error in case the effective gasTipCap is negative
 func (tx *Transaction) EffectiveGasTipValue(baseFee *big.Int) *big.Int {
-	effectiveTip, _ := tx.EffectiveGasTip(baseFee)
-	return effectiveTip
+	dst := new(big.Int)
+	tx.EffectiveGasTipInto(dst, baseFee)
+	return dst
 }
 
 // EffectiveGasTipCmp compares the effective gasTipCap of two transactions assuming the given base fee.
@@ -384,7 +393,11 @@ func (tx *Transaction) EffectiveGasTipCmp(other *Transaction, baseFee *big.Int)
 	if baseFee == nil {
 		return tx.GasTipCapCmp(other)
 	}
-	return tx.EffectiveGasTipValue(baseFee).Cmp(other.EffectiveGasTipValue(baseFee))
+	txTip := new(big.Int)
+	otherTip := new(big.Int)
+	tx.EffectiveGasTipInto(txTip, baseFee)
+	other.EffectiveGasTipInto(otherTip, baseFee)
+	return txTip.Cmp(otherTip)
 }
 
 // EffectiveGasTipIntCmp compares the effective gasTipCap of a transaction to the given gasTipCap.
@@ -392,7 +405,9 @@ func (tx *Transaction) EffectiveGasTipIntCmp(other *big.Int, baseFee *big.Int) i
 	if baseFee == nil {
 		return tx.GasTipCapIntCmp(other)
 	}
-	return tx.EffectiveGasTipValue(baseFee).Cmp(other)
+	txTip := new(big.Int)
+	tx.EffectiveGasTipInto(txTip, baseFee)
+	return txTip.Cmp(other)
 }
 
 // BlobGas returns the blob gas limit of the transaction for blob transactions, 0 otherwise.

core/types/transaction_test.go

@@ -29,6 +29,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
@@ -593,3 +594,101 @@ func BenchmarkHash(b *testing.B) {
 		signer.Hash(tx)
 	}
 }
+
+func BenchmarkEffectiveGasTip(b *testing.B) {
+	signer := LatestSigner(params.TestChainConfig)
+	key, _ := crypto.GenerateKey()
+	txdata := &DynamicFeeTx{
+		ChainID:   big.NewInt(1),
+		Nonce:     0,
+		GasTipCap: big.NewInt(2000000000),
+		GasFeeCap: big.NewInt(3000000000),
+		Gas:       21000,
+		To:        &common.Address{},
+		Value:     big.NewInt(0),
+		Data:      nil,
+	}
+	tx, _ := SignNewTx(key, signer, txdata)
+	baseFee := big.NewInt(1000000000) // 1 gwei
+
+	b.Run("Original", func(b *testing.B) {
+		b.ReportAllocs()
+		for i := 0; i < b.N; i++ {
+			_, err := tx.EffectiveGasTip(baseFee)
+			if err != nil {
+				b.Fatal(err)
+			}
+		}
+	})
+
+	b.Run("IntoMethod", func(b *testing.B) {
+		b.ReportAllocs()
+		dst := new(big.Int)
+		for i := 0; i < b.N; i++ {
+			err := tx.EffectiveGasTipInto(dst, baseFee)
+			if err != nil {
+				b.Fatal(err)
+			}
+		}
+	})
+}
+
+func TestEffectiveGasTipInto(t *testing.T) {
+	signer := LatestSigner(params.TestChainConfig)
+	key, _ := crypto.GenerateKey()
+
+	testCases := []struct {
+		tipCap  int64
+		feeCap  int64
+		baseFee *int64
+	}{
+		{tipCap: 1, feeCap: 100, baseFee: intPtr(50)},
+		{tipCap: 10, feeCap: 100, baseFee: intPtr(50)},
+		{tipCap: 50, feeCap: 100, baseFee: intPtr(50)},
+		{tipCap: 100, feeCap: 100, baseFee: intPtr(50)},
+		{tipCap: 1, feeCap: 50, baseFee: intPtr(50)},
+		{tipCap: 1, feeCap: 20, baseFee: intPtr(50)}, // Base fee higher than fee cap
+		{tipCap: 50, feeCap: 100, baseFee: intPtr(0)},
+		{tipCap: 50, feeCap: 100, baseFee: nil}, // nil base fee
+	}
+
+	for i, tc := range testCases {
+		txdata := &DynamicFeeTx{
+			ChainID:   big.NewInt(1),
+			Nonce:     0,
+			GasTipCap: big.NewInt(tc.tipCap),
+			GasFeeCap: big.NewInt(tc.feeCap),
+			Gas:       21000,
+			To:        &common.Address{},
+			Value:     big.NewInt(0),
+			Data:      nil,
+		}
+		tx, _ := SignNewTx(key, signer, txdata)
+
+		var baseFee *big.Int
+		if tc.baseFee != nil {
+			baseFee = big.NewInt(*tc.baseFee)
+		}
+
+		// Get result from original method
+		orig, origErr := tx.EffectiveGasTip(baseFee)
+
+		// Get result from new method
+		dst := new(big.Int)
+		newErr := tx.EffectiveGasTipInto(dst, baseFee)
+
+		// Compare results
+		if (origErr != nil) != (newErr != nil) {
+			t.Fatalf("case %d: error mismatch: orig %v, new %v", i, origErr, newErr)
+		}
+
+		if orig.Cmp(dst) != 0 {
+			t.Fatalf("case %d: result mismatch: orig %v, new %v", i, orig, dst)
+		}
+	}
+}
+
+// Helper function to create integer pointer
+func intPtr(i int64) *int64 {
+	return &i
+}