feat(bridge): only update gas price oracle for exceeding diff threshold (#319)

Co-authored-by: HAOYUatHZ <37070449+HAOYUatHZ@users.noreply.github.com>
Co-authored-by: Péter Garamvölgyi <peter@scroll.io>

bridge/config.json

@@ -20,6 +20,10 @@
         "tx_type": "LegacyTx",
         "min_balance": 100000000000000000000
       },
+      "gas_oracle_config": {
+        "min_gas_price": 0,
+        "gas_price_diff": 50000
+      },
       "message_sender_private_keys": [
         "1212121212121212121212121212121212121212121212121212121212121212"
       ],
@@ -48,6 +52,10 @@
         "tx_type": "LegacyTx",
         "min_balance": 100000000000000000000
       },
+      "gas_oracle_config": {
+        "min_gas_price": 0,
+        "gas_price_diff": 50000
+      },
       "message_sender_private_keys": [
         "1212121212121212121212121212121212121212121212121212121212121212"
       ],

bridge/config/relayer_config.go

@@ -42,15 +42,25 @@ type RelayerConfig struct {
 	// MessengerContractAddress store the scroll messenger contract address.
 	MessengerContractAddress common.Address `json:"messenger_contract_address"`
 	// GasPriceOracleContractAddress store the scroll messenger contract address.
-	GasPriceOracleContractAddress common.Address `json:"gas_proce_oracle_contract_address"`
+	GasPriceOracleContractAddress common.Address `json:"gas_price_oracle_contract_address"`
 	// sender config
 	SenderConfig *SenderConfig `json:"sender_config"`
+	// gas oracle config
+	GasOracleConfig *GasOracleConfig `json:"gas_oracle_config"`
 	// The private key of the relayer
 	MessageSenderPrivateKeys   []*ecdsa.PrivateKey `json:"-"`
 	GasOracleSenderPrivateKeys []*ecdsa.PrivateKey `json:"-"`
 	RollupSenderPrivateKeys    []*ecdsa.PrivateKey `json:"-"`
 }
 
+// GasOracleConfig The config for updating gas price oracle.
+type GasOracleConfig struct {
+	// MinGasPrice store the minimum gas price to set.
+	MinGasPrice uint64 `json:"min_gas_price"`
+	// GasPriceDiff store the percentage of gas price difference.
+	GasPriceDiff uint64 `json:"gas_price_diff"`
+}
+
 // relayerConfigAlias RelayerConfig alias name
 type relayerConfigAlias RelayerConfig
 

bridge/l1/relayer.go

@@ -22,6 +22,12 @@ import (
 	"scroll-tech/bridge/sender"
 )
 
+const (
+	gasPriceDiffPrecision = 1000000
+
+	defaultGasPriceDiff = 50000 // 5%
+)
+
 // Layer1Relayer is responsible for
 //  1. fetch pending L1Message from db
 //  2. relay pending message to layer 2 node
@@ -43,6 +49,10 @@ type Layer1Relayer struct {
 	gasOracleCh     <-chan *sender.Confirmation
 	l1GasOracleABI  *abi.ABI
 
+	lastGasPrice uint64
+	minGasPrice  uint64
+	gasPriceDiff uint64
+
 	stopCh chan struct{}
 }
 
@@ -63,6 +73,16 @@ func NewLayer1Relayer(ctx context.Context, db database.OrmFactory, cfg *config.R
 		return nil, err
 	}
 
+	var minGasPrice uint64
+	var gasPriceDiff uint64
+	if cfg.GasOracleConfig != nil {
+		minGasPrice = cfg.GasOracleConfig.MinGasPrice
+		gasPriceDiff = cfg.GasOracleConfig.GasPriceDiff
+	} else {
+		minGasPrice = 0
+		gasPriceDiff = defaultGasPriceDiff
+	}
+
 	return &Layer1Relayer{
 		ctx: ctx,
 		db:  db,
@@ -75,6 +95,9 @@ func NewLayer1Relayer(ctx context.Context, db database.OrmFactory, cfg *config.R
 		gasOracleCh:     gasOracleSender.ConfirmChan(),
 		l1GasOracleABI:  bridge_abi.L1GasPriceOracleABI,
 
+		minGasPrice:  minGasPrice,
+		gasPriceDiff: gasPriceDiff,
+
 		cfg:    cfg,
 		stopCh: make(chan struct{}),
 	}, nil
@@ -147,25 +170,31 @@ func (r *Layer1Relayer) ProcessGasPriceOracle() {
 	block := blocks[0]
 
 	if block.GasOracleStatus == types.GasOraclePending {
-		baseFee := big.NewInt(int64(block.BaseFee))
-		data, err := r.l1GasOracleABI.Pack("setL1BaseFee", baseFee)
-		if err != nil {
-			log.Error("Failed to pack setL1BaseFee", "block.Hash", block.Hash, "block.Height", block.Number, "block.BaseFee", block.BaseFee, "err", err)
-			return
-		}
-
-		hash, err := r.gasOracleSender.SendTransaction(block.Hash, &r.cfg.GasPriceOracleContractAddress, big.NewInt(0), data)
-		if err != nil {
-			if !errors.Is(err, sender.ErrNoAvailableAccount) {
-				log.Error("Failed to send setL1BaseFee tx to layer2 ", "block.Hash", block.Hash, "block.Height", block.Number, "err", err)
+		expectedDelta := r.lastGasPrice * r.gasPriceDiff / gasPriceDiffPrecision
+		// last is undefine or (block.BaseFee >= minGasPrice && exceed diff)
+		if r.lastGasPrice == 0 || (block.BaseFee >= r.minGasPrice && (block.BaseFee >= r.lastGasPrice+expectedDelta || block.BaseFee <= r.lastGasPrice-expectedDelta)) {
+			baseFee := big.NewInt(int64(block.BaseFee))
+			data, err := r.l1GasOracleABI.Pack("setL1BaseFee", baseFee)
+			if err != nil {
+				log.Error("Failed to pack setL1BaseFee", "block.Hash", block.Hash, "block.Height", block.Number, "block.BaseFee", block.BaseFee, "err", err)
+				return
 			}
-			return
-		}
 
-		err = r.db.UpdateL1GasOracleStatusAndOracleTxHash(r.ctx, block.Hash, types.GasOracleImporting, hash.String())
-		if err != nil {
-			log.Error("UpdateGasOracleStatusAndOracleTxHash failed", "block.Hash", block.Hash, "block.Height", block.Number, "err", err)
-			return
+			hash, err := r.gasOracleSender.SendTransaction(block.Hash, &r.cfg.GasPriceOracleContractAddress, big.NewInt(0), data)
+			if err != nil {
+				if !errors.Is(err, sender.ErrNoAvailableAccount) {
+					log.Error("Failed to send setL1BaseFee tx to layer2 ", "block.Hash", block.Hash, "block.Height", block.Number, "err", err)
+				}
+				return
+			}
+
+			err = r.db.UpdateL1GasOracleStatusAndOracleTxHash(r.ctx, block.Hash, types.GasOracleImporting, hash.String())
+			if err != nil {
+				log.Error("UpdateGasOracleStatusAndOracleTxHash failed", "block.Hash", block.Hash, "block.Height", block.Number, "err", err)
+				return
+			}
+			r.lastGasPrice = block.BaseFee
+			log.Info("Update l1 base fee", "txHash", hash.String(), "baseFee", baseFee)
 		}
 	}
 }

bridge/l2/relayer.go

@@ -29,6 +29,12 @@ import (
 	"scroll-tech/bridge/utils"
 )
 
+const (
+	gasPriceDiffPrecision = 1000000
+
+	defaultGasPriceDiff = 50000 // 5%
+)
+
 // Layer2Relayer is responsible for
 //  1. Committing and finalizing L2 blocks on L1
 //  2. Relaying messages from L2 to L1
@@ -55,6 +61,10 @@ type Layer2Relayer struct {
 	gasOracleCh     <-chan *sender.Confirmation
 	l2GasOracleABI  *abi.ABI
 
+	lastGasPrice uint64
+	minGasPrice  uint64
+	gasPriceDiff uint64
+
 	// A list of processing message.
 	// key(string): confirmation ID, value(string): layer2 hash.
 	processingMessage sync.Map
@@ -91,6 +101,16 @@ func NewLayer2Relayer(ctx context.Context, l2Client *ethclient.Client, db databa
 		return nil, err
 	}
 
+	var minGasPrice uint64
+	var gasPriceDiff uint64
+	if cfg.GasOracleConfig != nil {
+		minGasPrice = cfg.GasOracleConfig.MinGasPrice
+		gasPriceDiff = cfg.GasOracleConfig.GasPriceDiff
+	} else {
+		minGasPrice = 0
+		gasPriceDiff = defaultGasPriceDiff
+	}
+
 	return &Layer2Relayer{
 		ctx: ctx,
 		db:  db,
@@ -109,6 +129,9 @@ func NewLayer2Relayer(ctx context.Context, l2Client *ethclient.Client, db databa
 		gasOracleCh:     gasOracleSender.ConfirmChan(),
 		l2GasOracleABI:  bridge_abi.L2GasPriceOracleABI,
 
+		minGasPrice:  minGasPrice,
+		gasPriceDiff: gasPriceDiff,
+
 		cfg:                         cfg,
 		processingMessage:           sync.Map{},
 		processingBatchesCommitment: sync.Map{},
@@ -238,25 +261,32 @@ func (r *Layer2Relayer) ProcessGasPriceOracle() {
 			log.Error("Failed to fetch SuggestGasPrice from l2geth", "err", err)
 			return
 		}
+		suggestGasPriceUint64 := uint64(suggestGasPrice.Int64())
+		expectedDelta := r.lastGasPrice * r.gasPriceDiff / gasPriceDiffPrecision
 
-		data, err := r.l2GasOracleABI.Pack("setL2BaseFee", suggestGasPrice)
-		if err != nil {
-			log.Error("Failed to pack setL2BaseFee", "batch.Hash", batch.Hash, "block.BaseFee", suggestGasPrice.Uint64(), "err", err)
-			return
-		}
-
-		hash, err := r.gasOracleSender.SendTransaction(batch.Hash, &r.cfg.GasPriceOracleContractAddress, big.NewInt(0), data)
-		if err != nil {
-			if !errors.Is(err, sender.ErrNoAvailableAccount) {
-				log.Error("Failed to send setL2BaseFee tx to layer2 ", "batch.Hash", batch.Hash, "err", err)
+		// last is undefine or (suggestGasPriceUint64 >= minGasPrice && exceed diff)
+		if r.lastGasPrice == 0 || (suggestGasPriceUint64 >= r.minGasPrice && (suggestGasPriceUint64 >= r.lastGasPrice+expectedDelta || suggestGasPriceUint64 <= r.lastGasPrice-expectedDelta)) {
+			data, err := r.l2GasOracleABI.Pack("setL2BaseFee", suggestGasPrice)
+			if err != nil {
+				log.Error("Failed to pack setL2BaseFee", "batch.Hash", batch.Hash, "GasPrice", suggestGasPrice.Uint64(), "err", err)
+				return
 			}
-			return
-		}
 
-		err = r.db.UpdateL2GasOracleStatusAndOracleTxHash(r.ctx, batch.Hash, types.GasOracleImporting, hash.String())
-		if err != nil {
-			log.Error("UpdateGasOracleStatusAndOracleTxHash failed", "batch.Hash", batch.Hash, "err", err)
-			return
+			hash, err := r.gasOracleSender.SendTransaction(batch.Hash, &r.cfg.GasPriceOracleContractAddress, big.NewInt(0), data)
+			if err != nil {
+				if !errors.Is(err, sender.ErrNoAvailableAccount) {
+					log.Error("Failed to send setL2BaseFee tx to layer2 ", "batch.Hash", batch.Hash, "err", err)
+				}
+				return
+			}
+
+			err = r.db.UpdateL2GasOracleStatusAndOracleTxHash(r.ctx, batch.Hash, types.GasOracleImporting, hash.String())
+			if err != nil {
+				log.Error("UpdateGasOracleStatusAndOracleTxHash failed", "batch.Hash", batch.Hash, "err", err)
+				return
+			}
+			r.lastGasPrice = suggestGasPriceUint64
+			log.Info("Update l2 gas price", "txHash", hash.String(), "GasPrice", suggestGasPrice)
 		}
 	}
 }

common/types/batch.go

@@ -7,6 +7,7 @@ import (
 	"math/big"
 
 	"github.com/scroll-tech/go-ethereum/common"
+	"github.com/scroll-tech/go-ethereum/common/hexutil"
 	"github.com/scroll-tech/go-ethereum/core/types"
 	"github.com/scroll-tech/go-ethereum/crypto"
 
@@ -140,6 +141,7 @@ func NewBatchData(parentBatch *BlockBatch, blockTraces []*types.BlockTrace, piCf
 
 		// fill in RLP-encoded transactions
 		for _, txData := range trace.Transactions {
+			data, _ := hexutil.Decode(txData.Data)
 			// right now we only support legacy tx
 			tx := types.NewTx(&types.LegacyTx{
 				Nonce:    txData.Nonce,
@@ -147,15 +149,12 @@ func NewBatchData(parentBatch *BlockBatch, blockTraces []*types.BlockTrace, piCf
 				Value:    txData.Value.ToInt(),
 				Gas:      txData.Gas,
 				GasPrice: txData.GasPrice.ToInt(),
-				Data:     []byte(txData.Data),
+				Data:     data,
 				V:        txData.V.ToInt(),
 				R:        txData.R.ToInt(),
 				S:        txData.S.ToInt(),
 			})
-			var rlpBuf bytes.Buffer
-			writer := bufio.NewWriter(&rlpBuf)
-			_ = tx.EncodeRLP(writer)
-			rlpTxData := rlpBuf.Bytes()
+			rlpTxData, _ := tx.MarshalBinary()
 			var txLen [4]byte
 			binary.BigEndian.PutUint32(txLen[:], uint32(len(rlpTxData)))
 			_, _ = batchTxDataWriter.Write(txLen[:])
@@ -175,6 +174,10 @@ func NewBatchData(parentBatch *BlockBatch, blockTraces []*types.BlockTrace, piCf
 		}
 	}
 
+	if err := batchTxDataWriter.Flush(); err != nil {
+		panic("Buffered I/O flush failed")
+	}
+
 	batch.L2Transactions = batchTxDataBuf.Bytes()
 	batchData.piCfg = piCfg
 

common/version/version.go

@@ -5,7 +5,7 @@ import (
 	"runtime/debug"
 )
 
-var tag = "alpha-v1.4"
+var tag = "alpha-v1.8"
 
 var commit = func() string {
 	if info, ok := debug.ReadBuildInfo(); ok {