From 67a7a372a3931a0959a2422c753e97bddaa35961 Mon Sep 17 00:00:00 2001
From: David <david@taiko.xyz>
Date: Thu, 4 Jul 2024 17:05:52 +0800
Subject: [PATCH] feat(taiko-client): introduce `TryDecompressHekla()` (#17735)

---
 .../driver/chain_syncer/blob/syncer.go        | 10 ++++-
 .../txlist_decompressor.go                    | 41 +++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/packages/taiko-client/driver/chain_syncer/blob/syncer.go b/packages/taiko-client/driver/chain_syncer/blob/syncer.go
index 9cfea3c5a6..f07d2e6cff 100644
--- a/packages/taiko-client/driver/chain_syncer/blob/syncer.go
+++ b/packages/taiko-client/driver/chain_syncer/blob/syncer.go
@@ -16,6 +16,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 
 	"github.com/taikoxyz/taiko-mono/packages/taiko-client/bindings"
@@ -260,13 +261,20 @@ func (s *Syncer) onBlockProposed(
 		return fmt.Errorf("failed to fetch tx list: %w", err)
 	}
 
+	var decompressedTxListBytes []byte
+	if s.rpc.L2.ChainID.Cmp(params.HeklaNetworkID) == 0 {
+		decompressedTxListBytes = s.txListDecompressor.TryDecompressHekla(event.BlockId, txListBytes, event.Meta.BlobUsed)
+	} else {
+		decompressedTxListBytes = s.txListDecompressor.TryDecompress(event.BlockId, txListBytes, event.Meta.BlobUsed)
+	}
+
 	// Decompress the transactions list and try to insert a new head block to L2 EE.
 	payloadData, err := s.insertNewHead(
 		ctx,
 		event,
 		parent,
 		s.state.GetHeadBlockID(),
-		s.txListDecompressor.TryDecompress(event.BlockId, txListBytes, event.Meta.BlobUsed),
+		decompressedTxListBytes,
 		&rawdb.L1Origin{
 			BlockID:       event.BlockId,
 			L2BlockHash:   common.Hash{}, // Will be set by taiko-geth.
diff --git a/packages/taiko-client/driver/txlist_decompressor/txlist_decompressor.go b/packages/taiko-client/driver/txlist_decompressor/txlist_decompressor.go
index 80f6e553b2..e288115fc8 100644
--- a/packages/taiko-client/driver/txlist_decompressor/txlist_decompressor.go
+++ b/packages/taiko-client/driver/txlist_decompressor/txlist_decompressor.go
@@ -75,3 +75,44 @@ func (v *TxListDecompressor) TryDecompress(
 	log.Info("Transaction list is valid", "blockID", blockID)
 	return txListBytes
 }
+
+// TryDecompressHekla is the same as TryDecompress, but it's used for Hekla network with
+// an incorrect legacy bytes size check.
+// ref: https://github.com/taikoxyz/taiko-client/pull/783
+func (v *TxListDecompressor) TryDecompressHekla(
+	blockID *big.Int,
+	txListBytes []byte,
+	blobUsed bool,
+) []byte {
+	// If the transaction list is empty, it's valid.
+	if len(txListBytes) == 0 {
+		return []byte{}
+	}
+
+	var (
+		txs types.Transactions
+		err error
+	)
+
+	// Decompress the transaction list bytes.
+	if txListBytes, err = utils.Decompress(txListBytes); err != nil {
+		log.Info("Failed to decompress tx list bytes", "blockID", blockID, "error", err)
+		return []byte{}
+	}
+
+	// If calldata is used, the compressed bytes of the transaction list must be
+	// less than or equal to maxBytesPerTxList.
+	if !blobUsed && (len(txListBytes) > int(v.maxBytesPerTxList)) {
+		log.Info("Compressed transactions list binary too large", "length", len(txListBytes), "blockID", blockID)
+		return []byte{}
+	}
+
+	// Try to RLP decode the transaction list bytes.
+	if err = rlp.DecodeBytes(txListBytes, &txs); err != nil {
+		log.Info("Failed to decode transactions list bytes", "blockID", blockID, "error", err)
+		return []byte{}
+	}
+
+	log.Info("Transaction list is valid", "blockID", blockID)
+	return txListBytes
+}