eth: Update replacement tx logic for EIP-1559

eth/transactionManager.go

@@ -17,6 +17,11 @@ import (
 	"github.com/livepeer/go-livepeer/common"
 )
 
+// The default price bump required by geth is 10%
+// We add a little extra in addition to the 10% price bump just to be safe
+// priceBump is a % value from 0-100
+const priceBump uint64 = 11
+
 type transactionSenderReader interface {
 	ethereum.TransactionSender
 	ethereum.TransactionReader
@@ -150,29 +155,15 @@ func (tm *TransactionManager) replace(tx *types.Transaction) (*types.Transaction
 		return nil, ErrReplacingMinedTx
 	}
 
-	gasPrice := calcReplacementGasPrice(tx)
-
-	suggestedGasPrice := tm.gpm.GasPrice()
-
-	// If the suggested gas price is higher than the bumped gas price, use the suggested gas price
-	// This is to account for any wild market gas price increases between the time of the original tx submission and time
-	// of replacement tx submission
-	// Note: If the suggested gas price is lower than the bumped gas price because market gas prices have dropped
-	// since the time of the original tx submission we cannot use the lower suggested gas price and we still need to use
-	// the bumped gas price in order to properly replace a still pending tx
-	if suggestedGasPrice.Cmp(gasPrice) == 1 {
-		gasPrice = suggestedGasPrice
-	}
+	newRawTx := newReplacementTx(tx)
 
 	// Bump gas price exceeds max gas price, return early
 	max := tm.gpm.MaxGasPrice()
-	if max != nil && gasPrice.Cmp(max) > 0 {
-		return nil, fmt.Errorf("replacement gas price exceeds max gas price suggested=%v max=%v", gasPrice, max)
+	newGasPrice := calcGasPrice(newRawTx)
+	if max != nil && newGasPrice.Cmp(max) > 0 {
+		return nil, fmt.Errorf("replacement gas price exceeds max gas price suggested=%v max=%v", newGasPrice, max)
 	}
 
-	// Replacement raw tx uses same fields as old tx (reusing the same nonce is crucial) except the gas price is updated
-	newRawTx := types.NewTransaction(tx.Nonce(), *tx.To(), tx.Value(), tx.Gas(), gasPrice, tx.Data())
-
 	newSignedTx, err := tm.sig.SignTx(newRawTx)
 	if err != nil {
 		return nil, err
@@ -184,9 +175,9 @@ func (tm *TransactionManager) replace(tx *types.Transaction) (*types.Transaction
 		txLog.method = "unknown"
 	}
 	if sendErr != nil {
-		glog.Infof("\n%vEth Transaction%v\n\nReplacement transaction: \"%v\".  Gas Price: %v \nTransaction Failed: %v\n\n%v\n", strings.Repeat("*", 30), strings.Repeat("*", 30), txLog.method, newSignedTx.GasPrice().String(), sendErr, strings.Repeat("*", 75))
+		glog.Infof("\n%vEth Transaction%v\n\nReplacement transaction: \"%v\".  Priority Fee: %v Max Fee: %v \nTransaction Failed: %v\n\n%v\n", strings.Repeat("*", 30), strings.Repeat("*", 30), txLog.method, newSignedTx.GasTipCap().String(), newSignedTx.GasFeeCap().String(), sendErr, strings.Repeat("*", 75))
 	} else {
-		glog.Infof("\n%vEth Transaction%v\n\nReplacement transaction: \"%v\".  Hash: \"%v\".  Gas Price: %v \n\n%v\n", strings.Repeat("*", 30), strings.Repeat("*", 30), txLog.method, newSignedTx.Hash().String(), newSignedTx.GasPrice().String(), strings.Repeat("*", 75))
+		glog.Infof("\n%vEth Transaction%v\n\nReplacement transaction: \"%v\".  Hash: \"%v\".  Priority Fee: %v Max Fee: %v \n\n%v\n", strings.Repeat("*", 30), strings.Repeat("*", 30), txLog.method, newSignedTx.Hash().String(), newSignedTx.GasTipCap().String(), newSignedTx.GasFeeCap().String(), strings.Repeat("*", 75))
 	}
 
 	return newSignedTx, sendErr
@@ -243,19 +234,30 @@ func (tm *TransactionManager) checkTxLoop() {
 	}
 }
 
-// Updated gas price must be at least 10% greater than the gas price used for the original transaction in order
-// to submit a replacement transaction with the same nonce. 10% is not defined by the protocol, but is the default required price bump
-// used by many clients: https://github.com/ethereum/go-ethereum/blob/01a7e267dc6d7bbef94882542bbd01bd712f5548/core/tx_pool.go#L148
-// We add a little extra in addition to the 10% price bump just to be sure
-func calcReplacementGasPrice(tx *types.Transaction) *big.Int {
-	return new(big.Int).Add(
-		new(big.Int).Add(
-			tx.GasPrice(),
-			new(big.Int).Div(
-				tx.GasPrice(),
-				big.NewInt(10),
-			),
-		),
-		big.NewInt(10),
-	)
+func applyPriceBump(val *big.Int, priceBump uint64) *big.Int {
+	a := big.NewInt(100 + int64(priceBump))
+	b := new(big.Int).Mul(a, val)
+	return b.Div(b, big.NewInt(100))
+}
+
+// Calculate the gas price as gas tip cap + base fee
+func calcGasPrice(tx *types.Transaction) *big.Int {
+	// Assume that the gas fee cap is calculated as gas tip cap + (baseFee * 2)
+	baseFee := new(big.Int).Div(new(big.Int).Sub(tx.GasFeeCap(), tx.GasTipCap()), big.NewInt(2))
+	return new(big.Int).Add(baseFee, tx.GasTipCap())
+}
+
+func newReplacementTx(tx *types.Transaction) *types.Transaction {
+	baseTx := &types.DynamicFeeTx{
+		Nonce: tx.Nonce(),
+		// geth requires the price bump to be applied to both the gas tip cap and gas fee cap
+		GasFeeCap: applyPriceBump(tx.GasFeeCap(), priceBump),
+		GasTipCap: applyPriceBump(tx.GasTipCap(), priceBump),
+		Gas:       tx.Gas(),
+		Value:     tx.Value(),
+		Data:      tx.Data(),
+		To:        tx.To(),
+	}
+
+	return types.NewTx(baseTx)
 }

eth/transactionManager_test.go

@@ -15,7 +15,6 @@ import (
 	"github.com/golang/glog"
 	"github.com/livepeer/go-livepeer/pm"
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
 type stubTransactionSenderReader struct {
@@ -150,13 +149,14 @@ func TestTransactionManager_Wait(t *testing.T) {
 
 func TestTransactionManager_Replace(t *testing.T) {
 	assert := assert.New(t)
-	require := require.New(t)
 
 	eth := &stubTransactionSenderReader{
 		err: make(map[string]error),
 	}
 	q := transactionQueue{}
-	gasPrice := big.NewInt(10)
+	baseFee := big.NewInt(9)
+	gasTipCap := big.NewInt(1)
+	gasFeeCap := new(big.Int).Add(gasTipCap, new(big.Int).Mul(baseFee, big.NewInt(2)))
 	gpm := &GasPriceMonitor{
 		minGasPrice: big.NewInt(0),
 		maxGasPrice: big.NewInt(0),
@@ -170,7 +170,7 @@ func TestTransactionManager_Replace(t *testing.T) {
 		gpm:       gpm,
 	}
 
-	stubTx := types.NewTransaction(1, pm.RandAddress(), big.NewInt(100), 100000, gasPrice, pm.RandBytes(68))
+	stubTx := newStubDynamicFeeTx(gasFeeCap, gasTipCap)
 
 	// Test eth.TransactionByHash error
 	expErr := errors.New("TransactionByHash error")
@@ -195,7 +195,7 @@ func TestTransactionManager_Replace(t *testing.T) {
 	assert.Nil(tx)
 	assert.EqualError(
 		err,
-		fmt.Sprintf("replacement gas price exceeds max gas price suggested=%v max=%v", calcReplacementGasPrice(stubTx), gpm.maxGasPrice),
+		fmt.Sprintf("replacement gas price exceeds max gas price suggested=%v max=%v", applyPriceBump(calcGasPrice(stubTx), priceBump), gpm.maxGasPrice),
 	)
 	eth.err["TransactionByHash"] = nil
 
@@ -205,7 +205,7 @@ func TestTransactionManager_Replace(t *testing.T) {
 	assert.Nil(tx)
 	assert.EqualError(
 		err,
-		fmt.Sprintf("replacement gas price exceeds max gas price suggested=%v max=%v", calcReplacementGasPrice(stubTx), gpm.maxGasPrice),
+		fmt.Sprintf("replacement gas price exceeds max gas price suggested=%v max=%v", applyPriceBump(calcGasPrice(stubTx), priceBump), gpm.maxGasPrice),
 	)
 
 	// Error signing replacement tx
@@ -242,19 +242,7 @@ func TestTransactionManager_Replace(t *testing.T) {
 	tx, err = tm.replace(stubTx)
 	logsAfter = glog.Stats.Info.Lines()
 	assert.Nil(err)
-	expTx := types.NewTransaction(1, *stubTx.To(), stubTx.Value(), 100000, calcReplacementGasPrice(stubTx), stubTx.Data())
-	assert.Equal(tx.Hash(), expTx.Hash())
-	assert.Equal(logsAfter-logsBefore, int64(1))
-
-	// Replacement gas price lower than suggest gas price
-	// Use market gas price
-	gpm.gasPrice = big.NewInt(999)
-	require.True(gpm.GasPrice().Cmp(calcReplacementGasPrice(stubTx)) > 0)
-	logsBefore = glog.Stats.Info.Lines()
-	tx, err = tm.replace(stubTx)
-	logsAfter = glog.Stats.Info.Lines()
-	assert.Nil(err)
-	expTx = types.NewTransaction(1, *stubTx.To(), stubTx.Value(), 100000, gpm.gasPrice, stubTx.Data())
+	expTx := newReplacementTx(stubTx)
 	assert.Equal(tx.Hash(), expTx.Hash())
 	assert.Equal(logsAfter-logsBefore, int64(1))
 }
@@ -367,3 +355,74 @@ func TestTransactionManager_CheckTxLoop(t *testing.T) {
 	assert.Equal(eth.callsToTxByHash, tm.maxReplacements)
 	sub.Unsubscribe()
 }
+
+func TestApplyPriceBump(t *testing.T) {
+	assert := assert.New(t)
+
+	// priceBump = 0
+	// 500 * 1 = 500
+	res := applyPriceBump(big.NewInt(500), 0)
+	assert.Equal(big.NewInt(500), res)
+
+	// priceBump = 0.11
+	// 500 * 1.11 = 555
+	res = applyPriceBump(big.NewInt(500), 11)
+	assert.Equal(big.NewInt(555), res)
+
+	// priceBump = 0.17
+	// 500 * 1.17 = 585
+	res = applyPriceBump(big.NewInt(500), 17)
+	assert.Equal(big.NewInt(585), res)
+
+	// priceBump > 100
+	// 500 * 2.01 = 1005
+	res = applyPriceBump(big.NewInt(500), 101)
+	assert.Equal(big.NewInt(1005), res)
+
+	// Test round down when result is not a whole number
+	// 50 * 1.11 = 55.5 -> 55
+	res = applyPriceBump(big.NewInt(50), 11)
+	assert.Equal(big.NewInt(55), res)
+}
+
+func TestCalcGasPrice(t *testing.T) {
+	assert := assert.New(t)
+
+	baseFee := big.NewInt(1000)
+	gasTipCap := big.NewInt(100)
+	gasFeeCap := new(big.Int).Add(gasTipCap, new(big.Int).Mul(baseFee, big.NewInt(2)))
+	tx := newStubDynamicFeeTx(gasFeeCap, gasTipCap)
+
+	gasPrice := calcGasPrice(tx)
+	assert.Equal(new(big.Int).Add(baseFee, gasTipCap), gasPrice)
+}
+
+func TestNewReplacementTx(t *testing.T) {
+	assert := assert.New(t)
+
+	gasTipCap := big.NewInt(100)
+	gasFeeCap := big.NewInt(1000)
+
+	tx1 := newStubDynamicFeeTx(gasFeeCap, gasTipCap)
+	tx2 := newReplacementTx(tx1)
+	assert.NotEqual(tx1.Hash(), tx2.Hash())
+	assert.Equal(applyPriceBump(tx1.GasTipCap(), priceBump), tx2.GasTipCap())
+	assert.Equal(applyPriceBump(tx1.GasFeeCap(), priceBump), tx2.GasFeeCap())
+	assert.Equal(tx1.Nonce(), tx2.Nonce())
+	assert.Equal(tx1.Gas(), tx2.Gas())
+	assert.Equal(tx1.Value(), tx1.Value())
+	assert.Equal(tx1.To(), tx2.To())
+}
+
+func newStubDynamicFeeTx(gasFeeCap, gasTipCap *big.Int) *types.Transaction {
+	addr := pm.RandAddress()
+	return types.NewTx(&types.DynamicFeeTx{
+		Nonce:     1,
+		GasFeeCap: gasFeeCap,
+		GasTipCap: gasTipCap,
+		Gas:       1000000,
+		Value:     big.NewInt(100),
+		Data:      pm.RandBytes(68),
+		To:        &addr,
+	})
+}