feat(relayer): estimate l1 batch commit gas (#659)

Co-authored-by: HAOYUatHZ <haoyu@protonmail.com>

bridge/conf/config.json

@@ -78,14 +78,16 @@
       "max_l1_commit_gas_per_chunk": 11234567,
       "max_l1_commit_calldata_size_per_chunk": 112345,
       "min_l1_commit_calldata_size_per_chunk": 11234,
-      "chunk_timeout_sec": 300
+      "chunk_timeout_sec": 300,
+      "gas_cost_increase_multiplier": 1.2
     },
     "batch_proposer_config": {
       "max_chunk_num_per_batch": 112,
       "max_l1_commit_gas_per_batch": 11234567,
       "max_l1_commit_calldata_size_per_batch": 112345,
       "min_chunk_num_per_batch": 11,
-      "batch_timeout_sec": 300
+      "batch_timeout_sec": 300,
+      "gas_cost_increase_multiplier": 1.2
     }
   },
   "db_config": {

bridge/internal/config/l2.go

@@ -28,19 +28,21 @@ type L2Config struct {
 
 // ChunkProposerConfig loads chunk_proposer configuration items.
 type ChunkProposerConfig struct {
-	MaxTxGasPerChunk                uint64 `json:"max_tx_gas_per_chunk"`
-	MaxL2TxNumPerChunk              uint64 `json:"max_l2_tx_num_per_chunk"`
-	MaxL1CommitGasPerChunk          uint64 `json:"max_l1_commit_gas_per_chunk"`
-	MaxL1CommitCalldataSizePerChunk uint64 `json:"max_l1_commit_calldata_size_per_chunk"`
-	MinL1CommitCalldataSizePerChunk uint64 `json:"min_l1_commit_calldata_size_per_chunk"`
-	ChunkTimeoutSec                 uint64 `json:"chunk_timeout_sec"`
+	MaxTxGasPerChunk                uint64  `json:"max_tx_gas_per_chunk"`
+	MaxL2TxNumPerChunk              uint64  `json:"max_l2_tx_num_per_chunk"`
+	MaxL1CommitGasPerChunk          uint64  `json:"max_l1_commit_gas_per_chunk"`
+	MaxL1CommitCalldataSizePerChunk uint64  `json:"max_l1_commit_calldata_size_per_chunk"`
+	MinL1CommitCalldataSizePerChunk uint64  `json:"min_l1_commit_calldata_size_per_chunk"`
+	ChunkTimeoutSec                 uint64  `json:"chunk_timeout_sec"`
+	GasCostIncreaseMultiplier       float64 `json:"gas_cost_increase_multiplier"`
 }
 
 // BatchProposerConfig loads batch_proposer configuration items.
 type BatchProposerConfig struct {
-	MaxChunkNumPerBatch             uint64 `json:"max_chunk_num_per_batch"`
-	MaxL1CommitGasPerBatch          uint64 `json:"max_l1_commit_gas_per_batch"`
-	MaxL1CommitCalldataSizePerBatch uint32 `json:"max_l1_commit_calldata_size_per_batch"`
-	MinChunkNumPerBatch             uint64 `json:"min_chunk_num_per_batch"`
-	BatchTimeoutSec                 uint64 `json:"batch_timeout_sec"`
+	MaxChunkNumPerBatch             uint64  `json:"max_chunk_num_per_batch"`
+	MaxL1CommitGasPerBatch          uint64  `json:"max_l1_commit_gas_per_batch"`
+	MaxL1CommitCalldataSizePerBatch uint32  `json:"max_l1_commit_calldata_size_per_batch"`
+	MinChunkNumPerBatch             uint64  `json:"min_chunk_num_per_batch"`
+	BatchTimeoutSec                 uint64  `json:"batch_timeout_sec"`
+	GasCostIncreaseMultiplier       float64 `json:"gas_cost_increase_multiplier"`
 }

bridge/internal/controller/watcher/batch_proposer.go

@@ -28,6 +28,7 @@ type BatchProposer struct {
 	maxL1CommitCalldataSizePerBatch uint32
 	minChunkNumPerBatch             uint64
 	batchTimeoutSec                 uint64
+	gasCostIncreaseMultiplier       float64
 }
 
 // NewBatchProposer creates a new BatchProposer instance.
@@ -43,6 +44,7 @@ func NewBatchProposer(ctx context.Context, cfg *config.BatchProposerConfig, db *
 		maxL1CommitCalldataSizePerBatch: cfg.MaxL1CommitCalldataSizePerBatch,
 		minChunkNumPerBatch:             cfg.MinChunkNumPerBatch,
 		batchTimeoutSec:                 cfg.BatchTimeoutSec,
+		gasCostIncreaseMultiplier:       cfg.GasCostIncreaseMultiplier,
 	}
 }
 
@@ -99,11 +101,40 @@ func (p *BatchProposer) proposeBatchChunks() ([]*orm.Chunk, error) {
 	firstChunk := dbChunks[0]
 	totalL1CommitCalldataSize := firstChunk.TotalL1CommitCalldataSize
 	totalL1CommitGas := firstChunk.TotalL1CommitGas
-	var totalChunks uint64 = 1
+	totalChunks := uint64(1)
+	totalL1MessagePopped := firstChunk.TotalL1MessagesPoppedBefore + uint64(firstChunk.TotalL1MessagesPoppedInChunk)
+
+	parentBatch, err := p.batchOrm.GetLatestBatch(p.ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	getKeccakGas := func(size uint64) uint64 {
+		return 30 + 6*((size+31)/32) // 30 + 6 * ceil(size / 32)
+	}
+
+	// Add extra gas costs
+	totalL1CommitGas += 4 * 2100                                       // 4 one-time cold sload for commitBatch
+	totalL1CommitGas += 20000                                          // 1 time sstore
+	totalL1CommitGas += 16                                             // version in calldata
+	totalL1CommitGas += 16 * (32 * (totalL1MessagePopped + 255) / 256) // _skippedL1MessageBitmap in calldata
+
+	// adjusting gas:
+	// add 1 time cold sload (2100 gas) for L1MessageQueue
+	// add 1 time cold address access (2600 gas) for L1MessageQueue
+	// minus 1 time warm sload (100 gas) & 1 time warm address access (100 gas)
+	totalL1CommitGas += (2100 + 2600 - 100 - 100)
+	totalL1CommitGas += getKeccakGas(32 * totalChunks) // batch data hash
+	if parentBatch != nil {
+		totalL1CommitGas += getKeccakGas(uint64(len(parentBatch.BatchHeader))) // parent batch header hash
+		totalL1CommitGas += 16 * uint64(len(parentBatch.BatchHeader))          // parent batch header in calldata
+	}
+	// batch header size: 89 + 32 * ceil(l1MessagePopped / 256)
+	totalL1CommitGas += getKeccakGas(89 + 32*(totalL1MessagePopped+255)/256)
 
 	// Check if the first chunk breaks hard limits.
 	// If so, it indicates there are bugs in chunk-proposer, manual fix is needed.
-	if totalL1CommitGas > p.maxL1CommitGasPerBatch {
+	if p.gasCostIncreaseMultiplier*float64(totalL1CommitGas) > float64(p.maxL1CommitGasPerBatch) {
 		return nil, fmt.Errorf(
 			"the first chunk exceeds l1 commit gas limit; start block number: %v, end block number: %v, commit gas: %v, max commit gas limit: %v",
 			firstChunk.StartBlockNumber,
@@ -124,12 +155,21 @@ func (p *BatchProposer) proposeBatchChunks() ([]*orm.Chunk, error) {
 	}
 
 	for i, chunk := range dbChunks[1:] {
-		totalChunks++
 		totalL1CommitCalldataSize += chunk.TotalL1CommitCalldataSize
 		totalL1CommitGas += chunk.TotalL1CommitGas
+		// adjust batch data hash gas cost
+		totalL1CommitGas -= getKeccakGas(32 * totalChunks)
+		totalChunks++
+		totalL1CommitGas += getKeccakGas(32 * totalChunks)
+		// adjust batch header hash gas cost
+		totalL1CommitGas -= getKeccakGas(89 + 32*(totalL1MessagePopped+255)/256)
+		totalL1CommitGas -= 16 * (32 * (totalL1MessagePopped + 255) / 256)
+		totalL1MessagePopped += uint64(chunk.TotalL1MessagesPoppedInChunk)
+		totalL1CommitGas += 16 * (32 * (totalL1MessagePopped + 255) / 256)
+		totalL1CommitGas += getKeccakGas(89 + 32*(totalL1MessagePopped+255)/256)
 		if totalChunks > p.maxChunkNumPerBatch ||
 			totalL1CommitCalldataSize > p.maxL1CommitCalldataSizePerBatch ||
-			totalL1CommitGas > p.maxL1CommitGasPerBatch {
+			p.gasCostIncreaseMultiplier*float64(totalL1CommitGas) > float64(p.maxL1CommitGasPerBatch) {
 			return dbChunks[:i+1], nil
 		}
 	}

bridge/internal/controller/watcher/chunk_proposer.go

@@ -28,6 +28,7 @@ type ChunkProposer struct {
 	maxL1CommitCalldataSizePerChunk uint64
 	minL1CommitCalldataSizePerChunk uint64
 	chunkTimeoutSec                 uint64
+	gasCostIncreaseMultiplier       float64
 }
 
 // NewChunkProposer creates a new ChunkProposer instance.
@@ -43,6 +44,7 @@ func NewChunkProposer(ctx context.Context, cfg *config.ChunkProposerConfig, db *
 		maxL1CommitCalldataSizePerChunk: cfg.MaxL1CommitCalldataSizePerChunk,
 		minL1CommitCalldataSizePerChunk: cfg.MinL1CommitCalldataSizePerChunk,
 		chunkTimeoutSec:                 cfg.ChunkTimeoutSec,
+		gasCostIncreaseMultiplier:       cfg.GasCostIncreaseMultiplier,
 	}
 }
 
@@ -88,11 +90,12 @@ func (p *ChunkProposer) proposeChunk() (*types.Chunk, error) {
 		return nil, nil
 	}
 
-	firstBlock := blocks[0]
+	chunk := &types.Chunk{Blocks: blocks[:1]}
+	firstBlock := chunk.Blocks[0]
 	totalTxGasUsed := firstBlock.Header.GasUsed
 	totalL2TxNum := firstBlock.L2TxsNum()
 	totalL1CommitCalldataSize := firstBlock.EstimateL1CommitCalldataSize()
-	totalL1CommitGas := firstBlock.EstimateL1CommitGas()
+	totalL1CommitGas := chunk.EstimateL1CommitGas()
 
 	// Check if the first block breaks hard limits.
 	// If so, it indicates there are bugs in sequencer, manual fix is needed.
@@ -105,7 +108,7 @@ func (p *ChunkProposer) proposeChunk() (*types.Chunk, error) {
 		)
 	}
 
-	if totalL1CommitGas > p.maxL1CommitGasPerChunk {
+	if p.gasCostIncreaseMultiplier*float64(totalL1CommitGas) > float64(p.maxL1CommitGasPerChunk) {
 		return nil, fmt.Errorf(
 			"the first block exceeds l1 commit gas limit; block number: %v, commit gas: %v, max commit gas limit: %v",
 			firstBlock.Header.Number,
@@ -133,16 +136,17 @@ func (p *ChunkProposer) proposeChunk() (*types.Chunk, error) {
 		)
 	}
 
-	for i, block := range blocks[1:] {
+	for _, block := range blocks[1:] {
+		chunk.Blocks = append(chunk.Blocks, block)
 		totalTxGasUsed += block.Header.GasUsed
 		totalL2TxNum += block.L2TxsNum()
 		totalL1CommitCalldataSize += block.EstimateL1CommitCalldataSize()
-		totalL1CommitGas += block.EstimateL1CommitGas()
+		totalL1CommitGas = chunk.EstimateL1CommitGas()
 		if totalTxGasUsed > p.maxTxGasPerChunk ||
 			totalL2TxNum > p.maxL2TxNumPerChunk ||
 			totalL1CommitCalldataSize > p.maxL1CommitCalldataSizePerChunk ||
-			totalL1CommitGas > p.maxL1CommitGasPerChunk {
-			blocks = blocks[:i+1]
+			p.gasCostIncreaseMultiplier*float64(totalL1CommitGas) > float64(p.maxL1CommitGasPerChunk) {
+			chunk.Blocks = chunk.Blocks[:len(chunk.Blocks)-1] // remove the last block from chunk
 			break
 		}
 	}
@@ -165,5 +169,5 @@ func (p *ChunkProposer) proposeChunk() (*types.Chunk, error) {
 		)
 		return nil, nil
 	}
-	return &types.Chunk{Blocks: blocks}, nil
+	return chunk, nil
 }

bridge/internal/orm/batch.go

@@ -134,6 +134,9 @@ func (o *Batch) GetLatestBatch(ctx context.Context) (*Batch, error) {
 
 	var latestBatch Batch
 	if err := db.First(&latestBatch).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, nil
+		}
 		return nil, fmt.Errorf("Batch.GetLatestBatch error: %w", err)
 	}
 	return &latestBatch, nil
@@ -212,7 +215,7 @@ func (o *Batch) InsertBatch(ctx context.Context, startChunkIndex, endChunkIndex
 	}
 
 	parentBatch, err := o.GetLatestBatch(ctx)
-	if err != nil && !errors.Is(errors.Unwrap(err), gorm.ErrRecordNotFound) {
+	if err != nil {
 		log.Error("failed to get the latest batch", "err", err)
 		return nil, err
 	}

bridge/internal/orm/chunk.go

@@ -149,12 +149,10 @@ func (o *Chunk) InsertChunk(ctx context.Context, chunk *types.Chunk, dbTX ...*go
 	var totalL2TxGas uint64
 	var totalL2TxNum uint64
 	var totalL1CommitCalldataSize uint64
-	var totalL1CommitGas uint64
 	for _, block := range chunk.Blocks {
 		totalL2TxGas += block.Header.GasUsed
 		totalL2TxNum += block.L2TxsNum()
 		totalL1CommitCalldataSize += block.EstimateL1CommitCalldataSize()
-		totalL1CommitGas += block.EstimateL1CommitGas()
 	}
 
 	numBlocks := len(chunk.Blocks)
@@ -168,7 +166,7 @@ func (o *Chunk) InsertChunk(ctx context.Context, chunk *types.Chunk, dbTX ...*go
 		TotalL2TxGas:                 totalL2TxGas,
 		TotalL2TxNum:                 uint32(totalL2TxNum),
 		TotalL1CommitCalldataSize:    uint32(totalL1CommitCalldataSize),
-		TotalL1CommitGas:             totalL1CommitGas,
+		TotalL1CommitGas:             chunk.EstimateL1CommitGas(),
 		StartBlockTime:               chunk.Blocks[0].Header.Time,
 		TotalL1MessagesPoppedBefore:  totalL1MessagePoppedBefore,
 		TotalL1MessagesPoppedInChunk: uint32(chunk.NumL1Messages(totalL1MessagePoppedBefore)),

common/types/block.go

@@ -10,10 +10,7 @@ import (
 	"github.com/scroll-tech/go-ethereum/core/types"
 )
 
-const nonZeroByteGas uint64 = 16
-const zeroByteGas uint64 = 4
-
-// WrappedBlock contains the block's Header, Transactions and WithdrawRoot hash.
+// WrappedBlock contains the block's Header, Transactions and WithdrawTrieRoot hash.
 type WrappedBlock struct {
 	Header *types.Header `json:"header"`
 	// Transactions is only used for recover types.Transactions, the from of types.TransactionData field is missing.
@@ -78,16 +75,20 @@ func (w *WrappedBlock) EstimateL1CommitCalldataSize() uint64 {
 	return size
 }
 
-// EstimateL1CommitGas calculates the calldata gas in l1 commit approximately.
-// TODO: This will need to be adjusted.
-// The part added here is only the calldata cost,
-// but we have execution cost for verifying blocks / chunks / batches and storing the batch hash.
+// EstimateL1CommitGas calculates the total L1 commit gas for this block approximately.
 func (w *WrappedBlock) EstimateL1CommitGas() uint64 {
+	getKeccakGas := func(size uint64) uint64 {
+		return 30 + 6*((size+31)/32) // 30 + 6 * ceil(size / 32)
+	}
+
 	var total uint64
+	var numL1Messages uint64
 	for _, txData := range w.Transactions {
 		if txData.Type == types.L1MessageTxType {
+			numL1Messages++
 			continue
 		}
+
 		data, _ := hexutil.Decode(txData.Data)
 		tx := types.NewTx(&types.LegacyTx{
 			Nonce:    txData.Nonce,
@@ -101,26 +102,19 @@ func (w *WrappedBlock) EstimateL1CommitGas() uint64 {
 			S:        txData.S.ToInt(),
 		})
 		rlpTxData, _ := tx.MarshalBinary()
-
-		for _, b := range rlpTxData {
-			if b == 0 {
-				total += zeroByteGas
-			} else {
-				total += nonZeroByteGas
-			}
-		}
-
-		var txLen [4]byte
-		binary.BigEndian.PutUint32(txLen[:], uint32(len(rlpTxData)))
-
-		for _, b := range txLen {
-			if b == 0 {
-				total += zeroByteGas
-			} else {
-				total += nonZeroByteGas
-			}
-		}
+		txPayloadLength := uint64(len(rlpTxData))
+		total += 16 * txPayloadLength          // an over-estimate: treat each byte as non-zero
+		total += 16 * 4                        // size of a uint32 field
+		total += getKeccakGas(txPayloadLength) // l2 tx hash
 	}
+
+	// sload
+	total += 2100 * numL1Messages // numL1Messages times cold sload in L1MessageQueue
+
+	// staticcall
+	total += 100 * numL1Messages // numL1Messages times call to L1MessageQueue
+	total += 100 * numL1Messages // numL1Messages times warm address access to L1MessageQueue
+
 	return total
 }
 

common/types/chunk.go

@@ -135,3 +135,25 @@ func (c *Chunk) Hash(totalL1MessagePoppedBefore uint64) (common.Hash, error) {
 	hash := crypto.Keccak256Hash(dataBytes)
 	return hash, nil
 }
+
+// EstimateL1CommitGas calculates the total L1 commit gas for this chunk approximately
+func (c *Chunk) EstimateL1CommitGas() uint64 {
+	var totalTxNum uint64
+	var totalL1CommitGas uint64
+	for _, block := range c.Blocks {
+		totalTxNum += uint64(len(block.Transactions))
+		totalL1CommitGas += block.EstimateL1CommitGas()
+	}
+
+	numBlocks := uint64(len(c.Blocks))
+	totalL1CommitGas += 100 * numBlocks     // numBlocks times warm sload
+	totalL1CommitGas += 16                  // numBlocks field of chunk encoding in calldata
+	totalL1CommitGas += 16 * 60 * numBlocks // BlockContext in chunk
+
+	getKeccakGas := func(size uint64) uint64 {
+		return 30 + 6*((size+31)/32) // 30 + 6 * ceil(size / 32)
+	}
+
+	totalL1CommitGas += getKeccakGas(58*numBlocks + 32*totalTxNum) // chunk hash
+	return totalL1CommitGas
+}

common/version/version.go

@@ -5,7 +5,7 @@ import (
 	"runtime/debug"
 )
 
-var tag = "v4.0.33"
+var tag = "v4.0.34"
 
 var commit = func() string {
 	if info, ok := debug.ReadBuildInfo(); ok {