From ebe0755a97153b12eff823509fc71d74d9f7fe95 Mon Sep 17 00:00:00 2001
From: Elle Mouton <elle.mouton@gmail.com>
Date: Mon, 13 Nov 2023 14:38:28 +0200
Subject: [PATCH] channeldb: make MarkEdgeLive logic reusable

This commit is a set-up commit. It extracts the logic from
`MarkEdgeLive` to a helper `markEdgeLive` method so that the logic can
be called from within other kvdb.Update blocks. This will be used in the
next commit.
---
 channeldb/graph.go | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/channeldb/graph.go b/channeldb/graph.go
index 5d5cb45df..0a1b233e8 100644
--- a/channeldb/graph.go
+++ b/channeldb/graph.go
@@ -3580,10 +3580,17 @@ func markEdgeZombie(zombieIndex kvdb.RwBucket, chanID uint64, pubKey1,
 
 // MarkEdgeLive clears an edge from our zombie index, deeming it as live.
 func (c *ChannelGraph) MarkEdgeLive(chanID uint64) error {
+	return c.markEdgeLive(nil, chanID)
+}
+
+// markEdgeLive clears an edge from the zombie index. This method can be called
+// with an existing kvdb.RwTx or the argument can be set to nil in which case a
+// new transaction will be created.
+func (c *ChannelGraph) markEdgeLive(tx kvdb.RwTx, chanID uint64) error {
 	c.cacheMu.Lock()
 	defer c.cacheMu.Unlock()
 
-	err := kvdb.Update(c.db, func(tx kvdb.RwTx) error {
+	dbFn := func(tx kvdb.RwTx) error {
 		edges := tx.ReadWriteBucket(edgeBucket)
 		if edges == nil {
 			return ErrGraphNoEdgesFound
@@ -3601,7 +3608,16 @@ func (c *ChannelGraph) MarkEdgeLive(chanID uint64) error {
 		}
 
 		return zombieIndex.Delete(k[:])
-	}, func() {})
+	}
+
+	// If the transaction is nil, we'll create a new one. Otherwise, we use
+	// the existing transaction
+	var err error
+	if tx == nil {
+		err = kvdb.Update(c.db, dbFn, func() {})
+	} else {
+		err = dbFn(tx)
+	}
 	if err != nil {
 		return err
 	}
@@ -3611,11 +3627,12 @@ func (c *ChannelGraph) MarkEdgeLive(chanID uint64) error {
 
 	// We need to add the channel back into our graph cache, otherwise we
 	// won't use it for path finding.
-	edgeInfos, err := c.FetchChanInfos([]uint64{chanID})
-	if err != nil {
-		return err
-	}
 	if c.graphCache != nil {
+		edgeInfos, err := c.FetchChanInfos([]uint64{chanID})
+		if err != nil {
+			return err
+		}
+
 		for _, edgeInfo := range edgeInfos {
 			c.graphCache.AddChannel(
 				edgeInfo.Info, edgeInfo.Policy1,