feat: track latest relayed l1 message

core/blockchain.go

@@ -53,6 +53,7 @@ var (
 	headHeaderGauge    = metrics.NewRegisteredGauge("chain/head/header", nil)
 	headFastBlockGauge = metrics.NewRegisteredGauge("chain/head/receipt", nil)
 	headTimeGapGauge   = metrics.NewRegisteredGauge("chain/head/timegap", nil)
+	headL1MessageGauge = metrics.NewRegisteredGauge("chain/head/l1msg", nil)
 
 	l2BaseFeeGauge = metrics.NewRegisteredGauge("chain/fees/l2basefee", nil)
 
@@ -1253,6 +1254,17 @@ func (bc *BlockChain) writeBlockWithState(block *types.Block, receipts []*types.
 		l2BaseFeeGauge.Update(0)
 	}
 
+	// Note the latest relayed L1 message queue index (if any)
+	for _, tx := range block.Transactions() {
+		if msg := tx.AsL1MessageTx(); msg != nil {
+			// Queue index is guaranteed to fit into int64.
+			headL1MessageGauge.Update(int64(msg.QueueIndex))
+		} else {
+			// No more L1 messages in this block.
+			break
+		}
+	}
+
 	parent := bc.GetHeaderByHash(block.ParentHash())
 	// block.Time is guaranteed to be larger than parent.Time,
 	// and the time gap should fit into int64.

params/version.go

@@ -24,7 +24,7 @@ import (
 const (
 	VersionMajor = 5         // Major version component of the current release
 	VersionMinor = 8         // Minor version component of the current release
-	VersionPatch = 26        // Patch version component of the current release
+	VersionPatch = 27        // Patch version component of the current release
 	VersionMeta  = "mainnet" // Version metadata to append to the version string
 )