graph/db: version channelCache by gossip version

Add a channelCacheKey struct keyed by {GossipVersion, chanID}, matching
the pattern already used by rejectCache. This prevents v1 and v2
channel data from colliding in the shared cache.

All callers in KVStore (always GossipVersion1) and SQLStore (version
from context) are updated to pass the version parameter.

This will be needed for later on when we update methods that use this
cache to be versioned (like ChannelUpdatesInHorizon).

graph/db/kv_store.go

@@ -1186,7 +1186,9 @@ func (c *KVStore) AddChannelEdge(ctx context.Context,
 				c.rejectCache.remove(
 					lnwire.GossipVersion1, edge.ChannelID,
 				)
-				c.chanCache.remove(edge.ChannelID)
+				c.chanCache.remove(
+					lnwire.GossipVersion1, edge.ChannelID,
+				)
 
 				return nil
 			}
@@ -1588,7 +1590,7 @@ func (c *KVStore) PruneGraph(spentOutputs []*wire.OutPoint,
 
 	for _, channel := range chansClosed {
 		c.rejectCache.remove(lnwire.GossipVersion1, channel.ChannelID)
-		c.chanCache.remove(channel.ChannelID)
+		c.chanCache.remove(lnwire.GossipVersion1, channel.ChannelID)
 	}
 
 	return chansClosed, prunedNodes, nil
@@ -1855,7 +1857,7 @@ func (c *KVStore) DisconnectBlockAtHeight(height uint32) (
 
 	for _, channel := range removedChans {
 		c.rejectCache.remove(lnwire.GossipVersion1, channel.ChannelID)
-		c.chanCache.remove(channel.ChannelID)
+		c.chanCache.remove(lnwire.GossipVersion1, channel.ChannelID)
 	}
 
 	return removedChans, nil
@@ -1974,7 +1976,7 @@ func (c *KVStore) DeleteChannelEdges(v lnwire.GossipVersion,
 
 	for _, chanID := range chanIDs {
 		c.rejectCache.remove(lnwire.GossipVersion1, chanID)
-		c.chanCache.remove(chanID)
+		c.chanCache.remove(lnwire.GossipVersion1, chanID)
 	}
 
 	return infos, nil
@@ -2104,7 +2106,7 @@ func (c *KVStore) updateChanCacheBatch(edgesToCache map[uint64]ChannelEdge) {
 	defer c.cacheMu.Unlock()
 
 	for cid, edge := range edgesToCache {
-		c.chanCache.insert(cid, edge)
+		c.chanCache.insert(lnwire.GossipVersion1, cid, edge)
 	}
 }
 
@@ -2256,7 +2258,10 @@ func (c *KVStore) fetchNextChanUpdateBatch(
 			}
 
 			// Check cache (we already hold shared read lock).
-			if channel, ok := c.chanCache.get(chanIDInt); ok {
+			channel, ok := c.chanCache.get(
+				lnwire.GossipVersion1, chanIDInt,
+			)
+			if ok {
 				state.edgesSeen[chanIDInt] = struct{}{}
 
 				batch = append(batch, channel)
@@ -2300,7 +2305,7 @@ func (c *KVStore) fetchNextChanUpdateBatch(
 
 			// Now we have all the information we need to build the
 			// channel edge.
-			channel := ChannelEdge{
+			channel = ChannelEdge{
 				Info:    edgeInfo,
 				Policy1: edge1,
 				Policy2: edge2,
@@ -3302,13 +3307,16 @@ func (c *KVStore) updateEdgeCache(e *models.ChannelEdgePolicy,
 	// the entry with the updated policy for the direction that was just
 	// written. If the edge doesn't exist, we'll defer loading the info and
 	// policies and lazily read from disk during the next query.
-	if channel, ok := c.chanCache.get(e.ChannelID); ok {
+	channel, ok := c.chanCache.get(
+		lnwire.GossipVersion1, e.ChannelID,
+	)
+	if ok {
 		if isUpdate1 {
 			channel.Policy1 = e
 		} else {
 			channel.Policy2 = e
 		}
-		c.chanCache.insert(e.ChannelID, channel)
+		c.chanCache.insert(lnwire.GossipVersion1, e.ChannelID, channel)
 	}
 }
 
@@ -4215,7 +4223,7 @@ func (c *KVStore) MarkEdgeZombie(chanID uint64,
 	}
 
 	c.rejectCache.remove(lnwire.GossipVersion1, chanID)
-	c.chanCache.remove(chanID)
+	c.chanCache.remove(lnwire.GossipVersion1, chanID)
 
 	return nil
 }
@@ -4284,7 +4292,7 @@ func (c *KVStore) markEdgeLiveUnsafe(tx kvdb.RwTx, chanID uint64) error {
 	}
 
 	c.rejectCache.remove(lnwire.GossipVersion1, chanID)
-	c.chanCache.remove(chanID)
+	c.chanCache.remove(lnwire.GossipVersion1, chanID)
 
 	return nil
 }