Add a boolean field to tx receipt object indicating if the tx was timeboosted

arbitrum/apibackend.go

@@ -96,6 +96,7 @@ type SyncProgressBackend interface {
 	SyncProgressMap() map[string]interface{}
 	SafeBlockNumber(ctx context.Context) (uint64, error)
 	FinalizedBlockNumber(ctx context.Context) (uint64, error)
+	BlockMetadataByNumber(blockNum uint64) (common.BlockMetadata, error)
 }
 
 func createRegisterAPIBackend(backend *Backend, filterConfig filters.Config, fallbackClientUrl string, fallbackClientTimeout time.Duration) (*filters.FilterSystem, error) {
@@ -460,6 +461,10 @@ func (a *APIBackend) BlockByNumberOrHash(ctx context.Context, blockNrOrHash rpc.
 	return nil, errors.New("invalid arguments; neither block nor hash specified")
 }
 
+func (a *APIBackend) BlockMetadataByNumber(blockNum uint64) (common.BlockMetadata, error) {
+	return a.sync.BlockMetadataByNumber(blockNum)
+}
+
 func StateAndHeaderFromHeader(ctx context.Context, chainDb ethdb.Database, bc *core.BlockChain, maxRecreateStateDepth int64, header *types.Header, err error) (*state.StateDB, *types.Header, error) {
 	if err != nil {
 		return nil, header, err

common/types.go

@@ -486,3 +486,24 @@ func (b PrettyBytes) TerminalString() string {
 	}
 	return fmt.Sprintf("%#x...%x (%dB)", b[:3], b[len(b)-3:], len(b))
 }
+
+type BlockMetadata []byte
+
+// IsTxTimeboosted given a tx's index in the block returns whether the tx was timeboosted
+// or not. The first byte of blockMetadata byte array is reserved to indicate the version,
+// starting from the second byte, (N)th bit would represent if (N)th tx is timeboosted or not, 1 means yes and 0 means no
+// blockMetadata[index / 8 + 1] & (1 << (index % 8)) != 0; where index = (N - 1), implies whether (N)th tx in a block is timeboosted
+// note that number of txs in a block will always lag behind (len(blockMetadata) - 1) * 8 but it wont lag more than a value of 7
+func (b BlockMetadata) IsTxTimeboosted(txIndex int) (bool, error) {
+	if len(b) == 0 {
+		return false, errors.New("blockMetadata is not set")
+	}
+	if txIndex < 0 {
+		return false, fmt.Errorf("invalid transaction index- %d, should be positive", txIndex)
+	}
+	maxTxCount := (len(b) - 1) * 8
+	if txIndex >= maxTxCount {
+		return false, nil
+	}
+	return b[1+(txIndex/8)]&(1<<(txIndex%8)) != 0, nil
+}

eth/api_backend.go

@@ -182,6 +182,10 @@ func (b *EthAPIBackend) BlockByNumberOrHash(ctx context.Context, blockNrOrHash r
 	return nil, errors.New("invalid arguments; neither block nor hash specified")
 }
 
+func (b *EthAPIBackend) BlockMetadataByNumber(blockNum uint64) (common.BlockMetadata, error) {
+	return nil, nil
+}
+
 func (b *EthAPIBackend) Pending() (*types.Block, types.Receipts, *state.StateDB) {
 	return b.eth.miner.Pending()
 }

internal/ethapi/api.go

@@ -1983,6 +1983,17 @@ func marshalReceipt(ctx context.Context, receipt *types.Receipt, blockHash commo
 				fields["l1BlockNumber"] = hexutil.Uint64(arbTx.L1BlockNumber)
 			}
 		}
+
+		blockMetadata, err := backend.BlockMetadataByNumber(blockNumber)
+		if err != nil {
+			return nil, err
+		}
+		if blockMetadata != nil {
+			fields["timeboosted"], err = blockMetadata.IsTxTimeboosted(txIndex)
+			if err != nil {
+				log.Error("Error checking if a tx was timeboosted", "txIndex", txIndex, "txHash", tx.Hash(), "err", err)
+			}
+		}
 	}
 	return fields, nil
 }

internal/ethapi/api_test.go

@@ -527,6 +527,9 @@ func (b testBackend) BlockByNumberOrHash(ctx context.Context, blockNrOrHash rpc.
 	}
 	panic("unknown type rpc.BlockNumberOrHash")
 }
+func (b testBackend) BlockMetadataByNumber(blockNum uint64) (common.BlockMetadata, error) {
+	return nil, nil
+}
 func (b testBackend) GetBody(ctx context.Context, hash common.Hash, number rpc.BlockNumber) (*types.Body, error) {
 	return b.chain.GetBlock(hash, uint64(number.Int64())).Body(), nil
 }

internal/ethapi/backend.go

@@ -67,6 +67,7 @@ type Backend interface {
 	BlockByNumber(ctx context.Context, number rpc.BlockNumber) (*types.Block, error)
 	BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error)
 	BlockByNumberOrHash(ctx context.Context, blockNrOrHash rpc.BlockNumberOrHash) (*types.Block, error)
+	BlockMetadataByNumber(blockNum uint64) (common.BlockMetadata, error)
 	StateAndHeaderByNumber(ctx context.Context, number rpc.BlockNumber) (*state.StateDB, *types.Header, error)
 	StateAndHeaderByNumberOrHash(ctx context.Context, blockNrOrHash rpc.BlockNumberOrHash) (*state.StateDB, *types.Header, error)
 	Pending() (*types.Block, types.Receipts, *state.StateDB)

internal/ethapi/transaction_args_test.go

@@ -351,6 +351,9 @@ func (b *backendMock) BlockByHash(ctx context.Context, hash common.Hash) (*types
 func (b *backendMock) BlockByNumberOrHash(ctx context.Context, blockNrOrHash rpc.BlockNumberOrHash) (*types.Block, error) {
 	return nil, nil
 }
+func (b *backendMock) BlockMetadataByNumber(blockNum uint64) (common.BlockMetadata, error) {
+	return nil, nil
+}
 func (b *backendMock) GetBody(ctx context.Context, hash common.Hash, number rpc.BlockNumber) (*types.Body, error) {
 	return nil, nil
 }