Add option to force posting 4844 blobs

arbnode/batch_poster.go

@@ -134,6 +134,7 @@ type BatchPosterConfig struct {
 	RedisLock          redislock.SimpleCfg         `koanf:"redis-lock" reload:"hot"`
 	ExtraBatchGas      uint64                      `koanf:"extra-batch-gas" reload:"hot"`
 	Post4844Blobs      bool                        `koanf:"post-4844-blobs" reload:"hot"`
+	ForcePost4844Blobs bool                        `koanf:"force-post-4844-blobs" reload:"hot"`
 	ParentChainWallet  genericconf.WalletConfig    `koanf:"parent-chain-wallet"`
 	L1BlockBound       string                      `koanf:"l1-block-bound" reload:"hot"`
 	L1BlockBoundBypass time.Duration               `koanf:"l1-block-bound-bypass" reload:"hot"`
@@ -182,6 +183,7 @@ func BatchPosterConfigAddOptions(prefix string, f *pflag.FlagSet) {
 	f.String(prefix+".gas-refunder-address", DefaultBatchPosterConfig.GasRefunderAddress, "The gas refunder contract address (optional)")
 	f.Uint64(prefix+".extra-batch-gas", DefaultBatchPosterConfig.ExtraBatchGas, "use this much more gas than estimation says is necessary to post batches")
 	f.Bool(prefix+".post-4844-blobs", DefaultBatchPosterConfig.Post4844Blobs, "if the parent chain supports 4844 blobs and they're well priced, post EIP-4844 blobs")
+	f.Bool(prefix+".force-post-4844-blobs", DefaultBatchPosterConfig.ForcePost4844Blobs, "if the parent chain supports 4844 blobs and post-4844-blobs is true, post 4844 blobs even if it's not price efficient")
 	f.String(prefix+".redis-url", DefaultBatchPosterConfig.RedisUrl, "if non-empty, the Redis URL to store queued transactions in")
 	f.String(prefix+".l1-block-bound", DefaultBatchPosterConfig.L1BlockBound, "only post messages to batches when they're within the max future block/timestamp as of this L1 block tag (\"safe\", \"finalized\", \"latest\", or \"ignore\" to ignore this check)")
 	f.Duration(prefix+".l1-block-bound-bypass", DefaultBatchPosterConfig.L1BlockBoundBypass, "post batches even if not within the layer 1 future bounds if we're within this margin of the max delay")
@@ -205,6 +207,7 @@ var DefaultBatchPosterConfig = BatchPosterConfig{
 	GasRefunderAddress: "",
 	ExtraBatchGas:      50_000,
 	Post4844Blobs:      true,
+	ForcePost4844Blobs: false,
 	DataPoster:         dataposter.DefaultDataPosterConfig,
 	ParentChainWallet:  DefaultBatchPosterL1WalletConfig,
 	L1BlockBound:       "",
@@ -233,6 +236,7 @@ var TestBatchPosterConfig = BatchPosterConfig{
 	GasRefunderAddress: "",
 	ExtraBatchGas:      10_000,
 	Post4844Blobs:      true,
+	ForcePost4844Blobs: false,
 	DataPoster:         dataposter.TestDataPosterConfig,
 	ParentChainWallet:  DefaultBatchPosterL1WalletConfig,
 	L1BlockBound:       "",
@@ -1116,13 +1120,17 @@ func (b *BatchPoster) maybePostSequencerBatch(ctx context.Context) (bool, error)
 		return false, err
 	}
 	var use4844 bool
-	if config.Post4844Blobs && latestHeader.ExcessBlobGas != nil {
-		blobFeePerByte := eip4844.CalcBlobFee(eip4844.CalcExcessBlobGas(*latestHeader.ExcessBlobGas, *latestHeader.BlobGasUsed))
-		blobFeePerByte.Mul(blobFeePerByte, blobTxBlobGasPerBlob)
-		blobFeePerByte.Div(blobFeePerByte, usableBytesInBlob)
+	if config.Post4844Blobs && latestHeader.ExcessBlobGas != nil && latestHeader.BlobGasUsed != nil {
+		if config.ForcePost4844Blobs {
+			use4844 = true
+		} else {
+			blobFeePerByte := eip4844.CalcBlobFee(eip4844.CalcExcessBlobGas(*latestHeader.ExcessBlobGas, *latestHeader.BlobGasUsed))
+			blobFeePerByte.Mul(blobFeePerByte, blobTxBlobGasPerBlob)
+			blobFeePerByte.Div(blobFeePerByte, usableBytesInBlob)
 
-		calldataFeePerByte := arbmath.BigMulByUint(latestHeader.BaseFee, 16)
-		use4844 = arbmath.BigLessThan(blobFeePerByte, calldataFeePerByte)
+			calldataFeePerByte := arbmath.BigMulByUint(latestHeader.BaseFee, 16)
+			use4844 = arbmath.BigLessThan(blobFeePerByte, calldataFeePerByte)
+		}
 	}
 	data, kzgBlobs, err := b.encodeAddBatch(new(big.Int).SetUint64(batchPosition.NextSeqNum), batchPosition.MessageCount, b.building.msgCount, sequencerMsg, b.building.segments.delayedMsg, use4844)
 	if err != nil {

arbnode/dataposter/data_poster.go

@@ -463,11 +463,15 @@ func (p *DataPoster) feeAndTipCaps(ctx context.Context, nonce uint64, gasLimit u
 		return nil, nil, nil, fmt.Errorf("latest parent chain block %v missing BaseFee (either the parent chain does not have EIP-1559 or the parent chain node is not synced)", latestHeader.Number)
 	}
 	newBlobFeeCap := big.NewInt(0)
-	if latestHeader.ExcessBlobGas != nil {
+	if latestHeader.ExcessBlobGas != nil && latestHeader.BlobGasUsed != nil {
 		newBlobFeeCap = eip4844.CalcBlobFee(eip4844.CalcExcessBlobGas(*latestHeader.ExcessBlobGas, *latestHeader.BlobGasUsed))
 		newBlobFeeCap.Mul(newBlobFeeCap, common.Big2)
 	} else if numBlobs > 0 {
-		return nil, nil, nil, fmt.Errorf("latest parent chain block %v missing ExcessBlobGas but blobs were specified in data poster transaction (either the parent chain node is not synced or EIP-4844 was improperly activated)", latestHeader.Number)
+		return nil, nil, nil, fmt.Errorf(
+			"latest parent chain block %v missing ExcessBlobGas or BlobGasUsed but blobs were specified in data poster transaction "+
+				"(either the parent chain node is not synced or the EIP-4844 was improperly activated)",
+			latestHeader.Number,
+		)
 	}
 	softConfBlock := arbmath.BigSubByUint(latestHeader.Number, config.NonceRbfSoftConfs)
 	softConfNonce, err := p.client.NonceAt(ctx, p.Sender(), softConfBlock)