Allow previous gas limit

l2geth/eth/api_backend.go

@@ -377,6 +377,14 @@ func (b *EthAPIBackend) SuggestL2GasPrice(ctx context.Context) (*big.Int, error)
 	return b.rollupGpo.SuggestL2GasPrice(ctx)
 }
 
+func (b *EthAPIBackend) SuggestPreviousL1GasPrice(ctx context.Context) (*big.Int, error) {
+	return b.rollupGpo.SuggestPreviousL1GasPrice(ctx)
+}
+
+func (b *EthAPIBackend) SuggestPreviousL2GasPrice(ctx context.Context) (*big.Int, error) {
+	return b.rollupGpo.SuggestPreviousL2GasPrice(ctx)
+}
+
 func (b *EthAPIBackend) SetL1GasPrice(ctx context.Context, gasPrice *big.Int) error {
 	return b.rollupGpo.SetL1GasPrice(gasPrice)
 }
@@ -385,6 +393,14 @@ func (b *EthAPIBackend) SetL2GasPrice(ctx context.Context, gasPrice *big.Int) er
 	return b.rollupGpo.SetL2GasPrice(gasPrice)
 }
 
+func (b *EthAPIBackend) SetPreviousL1GasPrice(ctx context.Context, gasPrice *big.Int) error {
+	return b.rollupGpo.SetPreviousL1GasPrice(gasPrice)
+}
+
+func (b *EthAPIBackend) SetPreviousL2GasPrice(ctx context.Context, gasPrice *big.Int) error {
+	return b.rollupGpo.SetPreviousL2GasPrice(gasPrice)
+}
+
 func (b *EthAPIBackend) ChainDb() ethdb.Database {
 	return b.eth.ChainDb()
 }

l2geth/eth/gasprice/rollup_gasprice.go

@@ -10,19 +10,27 @@ import (
 
 // RollupOracle holds the L1 and L2 gas prices for fee calculation
 type RollupOracle struct {
-	l1GasPrice     *big.Int
-	l2GasPrice     *big.Int
-	l1GasPriceLock sync.RWMutex
-	l2GasPriceLock sync.RWMutex
+	l1GasPrice             *big.Int
+	l2GasPrice             *big.Int
+	previousL1GasPrice     *big.Int
+	previousL2GasPrice     *big.Int
+	l1GasPriceLock         sync.RWMutex
+	l2GasPriceLock         sync.RWMutex
+	previousL1GasPriceLock sync.RWMutex
+	previousL2GasPriceLock sync.RWMutex
 }
 
 // NewRollupOracle returns an initialized RollupOracle
 func NewRollupOracle() *RollupOracle {
 	return &RollupOracle{
-		l1GasPrice:     new(big.Int),
-		l2GasPrice:     new(big.Int),
-		l1GasPriceLock: sync.RWMutex{},
-		l2GasPriceLock: sync.RWMutex{},
+		l1GasPrice:             new(big.Int),
+		l2GasPrice:             new(big.Int),
+		previousL1GasPrice:     new(big.Int),
+		previousL2GasPrice:     new(big.Int),
+		l1GasPriceLock:         sync.RWMutex{},
+		l2GasPriceLock:         sync.RWMutex{},
+		previousL1GasPriceLock: sync.RWMutex{},
+		previousL2GasPriceLock: sync.RWMutex{},
 	}
 }
 
@@ -43,6 +51,23 @@ func (gpo *RollupOracle) SetL1GasPrice(gasPrice *big.Int) error {
 	return nil
 }
 
+// SuggestL1GasPrice returns the gas price which should be charged per byte of published
+// data by the sequencer.
+func (gpo *RollupOracle) SuggestPreviousL1GasPrice(ctx context.Context) (*big.Int, error) {
+	gpo.previousL1GasPriceLock.RLock()
+	defer gpo.previousL1GasPriceLock.RUnlock()
+	return gpo.previousL1GasPrice, nil
+}
+
+// SetL1GasPrice returns the current L1 gas price
+func (gpo *RollupOracle) SetPreviousL1GasPrice(gasPrice *big.Int) error {
+	gpo.previousL1GasPriceLock.Lock()
+	defer gpo.previousL1GasPriceLock.Unlock()
+	gpo.previousL1GasPrice = gasPrice
+	log.Info("Set Previous L1 Gas Price", "gasprice", gpo.previousL1GasPrice)
+	return nil
+}
+
 // SuggestL2GasPrice returns the gas price which should be charged per unit of gas
 // set manually by the sequencer depending on congestion
 func (gpo *RollupOracle) SuggestL2GasPrice(ctx context.Context) (*big.Int, error) {
@@ -59,3 +84,20 @@ func (gpo *RollupOracle) SetL2GasPrice(gasPrice *big.Int) error {
 	log.Info("Set L2 Gas Price", "gasprice", gpo.l2GasPrice)
 	return nil
 }
+
+// SuggestL2GasPrice returns the gas price which should be charged per unit of gas
+// set manually by the sequencer depending on congestion
+func (gpo *RollupOracle) SuggestPreviousL2GasPrice(ctx context.Context) (*big.Int, error) {
+	gpo.previousL2GasPriceLock.RLock()
+	defer gpo.previousL2GasPriceLock.RUnlock()
+	return gpo.previousL2GasPrice, nil
+}
+
+// SetL2GasPrice returns the current L2 gas price
+func (gpo *RollupOracle) SetPreviousL2GasPrice(gasPrice *big.Int) error {
+	gpo.previousL2GasPriceLock.Lock()
+	defer gpo.previousL2GasPriceLock.Unlock()
+	gpo.previousL2GasPrice = gasPrice
+	log.Info("Set Previous L2 Gas Price", "gasprice", gpo.previousL2GasPrice)
+	return nil
+}

l2geth/internal/ethapi/api.go

@@ -1959,6 +1959,17 @@ func (api *PrivateRollupAPI) SetL2GasPrice(ctx context.Context, gasPrice hexutil
 	return api.b.SetL2GasPrice(ctx, (*big.Int)(&gasPrice))
 }
 
+// SetPreviousL1GasPrice sets the gas price to be used when quoting calldata publishing costs
+// to users
+func (api *PrivateRollupAPI) SetPreviousL1GasPrice(ctx context.Context, gasPrice hexutil.Big) error {
+	return api.b.SetPreviousL1GasPrice(ctx, (*big.Int)(&gasPrice))
+}
+
+// SetPreviousL2GasPrice sets the gas price to be used when executing transactions on
+func (api *PrivateRollupAPI) SetPreviousL2GasPrice(ctx context.Context, gasPrice hexutil.Big) error {
+	return api.b.SetPreviousL2GasPrice(ctx, (*big.Int)(&gasPrice))
+}
+
 // PublicDebugAPI is the collection of Ethereum APIs exposed over the public
 // debugging endpoint.
 type PublicDebugAPI struct {

l2geth/internal/ethapi/backend.go

@@ -95,6 +95,10 @@ type Backend interface {
 	SetL1GasPrice(context.Context, *big.Int) error
 	SuggestL2GasPrice(context.Context) (*big.Int, error)
 	SetL2GasPrice(context.Context, *big.Int) error
+	SuggestPreviousL1GasPrice(ctx context.Context) (*big.Int, error)
+	SetPreviousL1GasPrice(context.Context, *big.Int) error
+	SuggestPreviousL2GasPrice(context.Context) (*big.Int, error)
+	SetPreviousL2GasPrice(context.Context, *big.Int) error
 	IngestTransactions([]*types.Transaction) error
 }
 

l2geth/les/api_backend.go

@@ -296,6 +296,26 @@ func (b *LesApiBackend) SetL2GasPrice(ctx context.Context, gasPrice *big.Int) er
 	panic("SetExecutionPrice is not implemented")
 }
 
+// NB: Non sequencer nodes cannot suggest L1 gas prices.
+func (b *LesApiBackend) SuggestPreviousL1GasPrice(ctx context.Context) (*big.Int, error) {
+	panic("SuggestPreviousL1GasPrice not implemented")
+}
+
+// NB: Non sequencer nodes cannot suggest L2 execution gas prices.
+func (b *LesApiBackend) SuggestPreviousL2GasPrice(ctx context.Context) (*big.Int, error) {
+	panic("SuggestPreviousL2GasPrice not implemented")
+}
+
+// NB: Non sequencer nodes cannot set Previous L1 gas prices.
+func (b *LesApiBackend) SetPreviousL1GasPrice(ctx context.Context, gasPrice *big.Int) error {
+	panic("SetDataPrice is not implemented")
+}
+
+// NB: Non sequencer nodes cannot set Previous L2 execution prices.
+func (b *LesApiBackend) SetPreviousL2GasPrice(ctx context.Context, gasPrice *big.Int) error {
+	panic("SetExecutionPrice is not implemented")
+}
+
 func (b *LesApiBackend) ChainDb() ethdb.Database {
 	return b.eth.chainDb
 }

l2geth/rollup/fees/rollup_fee.go

@@ -105,8 +105,8 @@ func DecodeL2GasLimitU64(gasLimit uint64) uint64 {
 
 // PaysEnoughOpts represent the options to PaysEnough
 type PaysEnoughOpts struct {
-	UserFee, ExpectedFee       *big.Int
-	ThresholdUp, ThresholdDown *big.Float
+	UserFee, ExpectedFee, ExpectedPreviousFee *big.Int
+	ThresholdUp, ThresholdDown                *big.Float
 }
 
 // PaysEnough returns an error if the fee is not large enough
@@ -118,24 +118,37 @@ func PaysEnough(opts *PaysEnoughOpts) error {
 	if opts.ExpectedFee == nil {
 		return fmt.Errorf("%w: no expected fee", errMissingInput)
 	}
+	if opts.ExpectedPreviousFee == nil {
+		return fmt.Errorf("%w: no expected previous fee", errMissingInput)
+	}
 
 	fee := new(big.Int).Set(opts.ExpectedFee)
+	previousFee := new(big.Int).Set(opts.ExpectedPreviousFee)
+
 	// Allow for a downward buffer to protect against L1 gas price volatility
 	if opts.ThresholdDown != nil {
 		fee = mulByFloat(fee, opts.ThresholdDown)
+		previousFee = mulByFloat(previousFee, opts.ThresholdDown)
 	}
 	// Protect the sequencer from being underpaid
 	// if user fee < expected fee, return error
-	if opts.UserFee.Cmp(fee) == -1 {
+	if opts.UserFee.Cmp(fee) == -1 && opts.UserFee.Cmp(previousFee) == -1 {
 		return ErrFeeTooLow
 	}
 	// Protect users from overpaying by too much
 	if opts.ThresholdUp != nil {
 		// overpaying = user fee - expected fee
 		overpaying := new(big.Int).Sub(opts.UserFee, opts.ExpectedFee)
 		threshold := mulByFloat(opts.ExpectedFee, opts.ThresholdUp)
-		// if overpaying > threshold, return error
-		if overpaying.Cmp(threshold) == 1 {
+
+		// also allow previous value
+		overpayingPrevious := new(big.Int).Sub(opts.UserFee, opts.ExpectedPreviousFee)
+		thresholdPrevious := mulByFloat(opts.ExpectedPreviousFee, opts.ThresholdUp)
+
+		// if overpaying > threshold && 
+		// overpayingPrevious > thresholdPrevious, return error
+		if (overpaying.Cmp(threshold) == 1 && 
+		    overpayingPrevious.Cmp(thresholdPrevious) == 1) {
 			return ErrFeeTooHigh
 		}
 	}

l2geth/rollup/fees/rollup_fee_test.go

@@ -112,82 +112,91 @@ func TestPaysEnough(t *testing.T) {
 	}{
 		"missing-gas-price": {
 			opts: &PaysEnoughOpts{
-				UserFee:       nil,
-				ExpectedFee:   new(big.Int),
-				ThresholdUp:   nil,
-				ThresholdDown: nil,
+				UserFee:             nil,
+				ExpectedFee:         new(big.Int),
+				ExpectedPreviousFee: new(big.Int),
+				ThresholdUp:         nil,
+				ThresholdDown:       nil,
 			},
 			err: errMissingInput,
 		},
 		"missing-fee": {
 			opts: &PaysEnoughOpts{
-				UserFee:       nil,
-				ExpectedFee:   nil,
-				ThresholdUp:   nil,
-				ThresholdDown: nil,
+				UserFee:             nil,
+				ExpectedFee:         nil,
+				ExpectedPreviousFee: nil,
+				ThresholdUp:         nil,
+				ThresholdDown:       nil,
 			},
 			err: errMissingInput,
 		},
 		"equal-fee": {
 			opts: &PaysEnoughOpts{
-				UserFee:       common.Big1,
-				ExpectedFee:   common.Big1,
-				ThresholdUp:   nil,
-				ThresholdDown: nil,
+				UserFee:             common.Big1,
+				ExpectedFee:         common.Big1,
+				ExpectedPreviousFee: common.Big1,
+				ThresholdUp:         nil,
+				ThresholdDown:       nil,
 			},
 			err: nil,
 		},
 		"fee-too-low": {
 			opts: &PaysEnoughOpts{
-				UserFee:       common.Big1,
-				ExpectedFee:   common.Big2,
-				ThresholdUp:   nil,
-				ThresholdDown: nil,
+				UserFee:             common.Big1,
+				ExpectedFee:         common.Big2,
+				ExpectedPreviousFee: common.Big2,
+				ThresholdUp:         nil,
+				ThresholdDown:       nil,
 			},
 			err: ErrFeeTooLow,
 		},
 		"fee-threshold-down": {
 			opts: &PaysEnoughOpts{
-				UserFee:       common.Big1,
-				ExpectedFee:   common.Big2,
-				ThresholdUp:   nil,
-				ThresholdDown: new(big.Float).SetFloat64(0.5),
+				UserFee:             common.Big1,
+				ExpectedFee:         common.Big2,
+				ExpectedPreviousFee: common.Big2,
+				ThresholdUp:         nil,
+				ThresholdDown:       new(big.Float).SetFloat64(0.5),
 			},
 			err: nil,
 		},
 		"fee-threshold-up": {
 			opts: &PaysEnoughOpts{
-				UserFee:       common.Big256,
-				ExpectedFee:   common.Big1,
-				ThresholdUp:   new(big.Float).SetFloat64(1.5),
-				ThresholdDown: nil,
+				UserFee:             common.Big256,
+				ExpectedFee:         common.Big1,
+				ExpectedPreviousFee: common.Big1,
+				ThresholdUp:         new(big.Float).SetFloat64(1.5),
+				ThresholdDown:       nil,
 			},
 			err: ErrFeeTooHigh,
 		},
 		"fee-too-low-high": {
 			opts: &PaysEnoughOpts{
-				UserFee:       new(big.Int).SetUint64(10_000),
-				ExpectedFee:   new(big.Int).SetUint64(1),
-				ThresholdUp:   new(big.Float).SetFloat64(3),
-				ThresholdDown: new(big.Float).SetFloat64(0.8),
+				UserFee:             new(big.Int).SetUint64(10_000),
+				ExpectedFee:         new(big.Int).SetUint64(1),
+				ExpectedPreviousFee: new(big.Int).SetUint64(1),
+				ThresholdUp:         new(big.Float).SetFloat64(3),
+				ThresholdDown:       new(big.Float).SetFloat64(0.8),
 			},
 			err: ErrFeeTooHigh,
 		},
 		"fee-too-low-down": {
 			opts: &PaysEnoughOpts{
-				UserFee:       new(big.Int).SetUint64(1),
-				ExpectedFee:   new(big.Int).SetUint64(10_000),
-				ThresholdUp:   new(big.Float).SetFloat64(3),
-				ThresholdDown: new(big.Float).SetFloat64(0.8),
+				UserFee:             new(big.Int).SetUint64(1),
+				ExpectedFee:         new(big.Int).SetUint64(10_000),
+				ExpectedPreviousFee: new(big.Int).SetUint64(10_000),
+				ThresholdUp:         new(big.Float).SetFloat64(3),
+				ThresholdDown:       new(big.Float).SetFloat64(0.8),
 			},
 			err: ErrFeeTooLow,
 		},
 		"fee-too-low-down-2": {
 			opts: &PaysEnoughOpts{
-				UserFee:       new(big.Int).SetUint64(0),
-				ExpectedFee:   new(big.Int).SetUint64(10_000),
-				ThresholdUp:   new(big.Float).SetFloat64(3),
-				ThresholdDown: new(big.Float).SetFloat64(0.8),
+				UserFee:             new(big.Int).SetUint64(0),
+				ExpectedFee:         new(big.Int).SetUint64(10_000),
+				ExpectedPreviousFee: new(big.Int).SetUint64(10_000),
+				ThresholdUp:         new(big.Float).SetFloat64(3),
+				ThresholdDown:       new(big.Float).SetFloat64(0.8),
 			},
 			err: ErrFeeTooLow,
 		},