graph/db: fix linter issues of old code

Since we have renamed a file housing some very old code, the linter has
now run on all this code for the first time. So we gotta do some
clean-up work here to make it happy.

docs/release-notes/release-notes-0.19.0.md

@@ -321,6 +321,8 @@ The underlying functionality between those two options remain the same.
     - [Abstract autopilot access](https://github.com/lightningnetwork/lnd/pull/9480)
     - [Abstract invoicerpc server access](https://github.com/lightningnetwork/lnd/pull/9516)
     - [Refactor to hide DB transactions](https://github.com/lightningnetwork/lnd/pull/9513)
+    - Move the graph cache out of the graph CRUD layer:
+      - [1](https://github.com/lightningnetwork/lnd/pull/9533)
 
 * [Golang was updated to
   `v1.22.11`](https://github.com/lightningnetwork/lnd/pull/9462). 

graph/db/kv_store.go

@@ -132,8 +132,8 @@ var (
 	//
 	// The chanID represents the channel ID of the edge and the direction is
 	// one byte representing the direction of the edge. The main purpose of
-	// this index is to allow pruning disabled channels in a fast way without
+	// this index is to allow pruning disabled channels in a fast way
-	// the need to iterate all over the graph.
+	// without the need to iterate all over the graph.
 	disabledEdgePolicyBucket = []byte("disabled-edge-policy-index")
 
 	// graphMetaBucket is a top-level bucket which stores various meta-deta
@@ -308,7 +308,7 @@ func (c *KVStore) getChannelMap(edges kvdb.RBucket) (
 		switch {
 		// If the db policy was missing an expected optional field, we
 		// return nil as if the policy was unknown.
-		case err == ErrEdgePolicyOptionalFieldNotFound:
+		case errors.Is(err, ErrEdgePolicyOptionalFieldNotFound):
 			return nil
 
 		case err != nil:
@@ -340,10 +340,13 @@ func (c *KVStore) Wipe() error {
 	err := kvdb.Update(c.db, func(tx kvdb.RwTx) error {
 		for _, tlb := range graphTopLevelBuckets {
 			err := tx.DeleteTopLevelBucket(tlb)
-			if err != nil && err != kvdb.ErrBucketNotFound {
+			if err != nil &&
+				!errors.Is(err, kvdb.ErrBucketNotFound) {
+
 				return err
 			}
 		}
+
 		return nil
 	}, func() {})
 	if err != nil {
@@ -395,6 +398,7 @@ func initKVStore(db kvdb.Backend) error {
 
 		graphMeta := tx.ReadWriteBucket(graphMetaBucket)
 		_, err = graphMeta.CreateBucketIfNotExists(pruneLogBucket)
+
 		return err
 	}, func() {})
 	if err != nil {
@@ -550,6 +554,7 @@ func (c *KVStore) forEachNodeDirectedChannel(tx kvdb.RTx,
 
 		return cb(directedChannel)
 	}
+
 	return nodeTraversal(tx, node[:], c.db, dbCallback)
 }
 
@@ -565,14 +570,14 @@ func (c *KVStore) fetchNodeFeatures(tx kvdb.RTx,
 
 	// Fallback that uses the database.
 	targetNode, err := c.FetchLightningNodeTx(tx, node)
-	switch err {
+	switch {
 	// If the node exists and has features, return them directly.
-	case nil:
+	case err == nil:
 		return targetNode.Features, nil
 
 	// If we couldn't find a node announcement, populate a blank feature
 	// vector.
-	case ErrGraphNodeNotFound:
+	case errors.Is(err, ErrGraphNodeNotFound):
 		return lnwire.EmptyFeatureVector(), nil
 
 	// Otherwise, bubble the error up.
@@ -915,7 +920,7 @@ func (c *KVStore) SetSourceNode(node *models.LightningNode) error {
 // already present node from a node announcement, or to insert a node found in a
 // channel update.
 //
-// TODO(roasbeef): also need sig of announcement
+// TODO(roasbeef): also need sig of announcement.
 func (c *KVStore) AddLightningNode(node *models.LightningNode,
 	op ...batch.SchedulerOption) error {
 
@@ -984,6 +989,7 @@ func (c *KVStore) LookupAlias(pub *btcec.PublicKey) (string, error) {
 		// TODO(roasbeef): should actually be using the utf-8
 		// package...
 		alias = string(a)
+
 		return nil
 	}, func() {
 		alias = ""
@@ -1076,7 +1082,7 @@ func (c *KVStore) AddChannelEdge(edge *models.ChannelEdgeInfo,
 
 			// Silence ErrEdgeAlreadyExist so that the batch can
 			// succeed, but propagate the error via local state.
-			if err == ErrEdgeAlreadyExist {
+			if errors.Is(err, ErrEdgeAlreadyExist) {
 				alreadyExists = true
 				return nil
 			}
@@ -1150,7 +1156,7 @@ func (c *KVStore) addChannelEdge(tx kvdb.RwTx,
 	// public key, so subsequent validation and queries can work properly.
 	_, node1Err := fetchLightningNode(nodes, edge.NodeKey1Bytes[:])
 	switch {
-	case node1Err == ErrGraphNodeNotFound:
+	case errors.Is(node1Err, ErrGraphNodeNotFound):
 		node1Shell := models.LightningNode{
 			PubKeyBytes:          edge.NodeKey1Bytes,
 			HaveNodeAnnouncement: false,
@@ -1166,7 +1172,7 @@ func (c *KVStore) addChannelEdge(tx kvdb.RwTx,
 
 	_, node2Err := fetchLightningNode(nodes, edge.NodeKey2Bytes[:])
 	switch {
-	case node2Err == ErrGraphNodeNotFound:
+	case errors.Is(node2Err, ErrGraphNodeNotFound):
 		node2Shell := models.LightningNode{
 			PubKeyBytes:          edge.NodeKey2Bytes,
 			HaveNodeAnnouncement: false,
@@ -1206,6 +1212,7 @@ func (c *KVStore) addChannelEdge(tx kvdb.RwTx,
 	if err := WriteOutpoint(&b, &edge.ChannelPoint); err != nil {
 		return err
 	}
+
 	return chanIndex.Put(b.Bytes(), chanKey[:])
 }
 
@@ -1233,6 +1240,7 @@ func (c *KVStore) HasChannelEdge(
 		upd1Time = time.Unix(entry.upd1Time, 0)
 		upd2Time = time.Unix(entry.upd2Time, 0)
 		exists, isZombie = entry.flags.unpack()
+
 		return upd1Time, upd2Time, exists, isZombie, nil
 	}
 	c.cacheMu.RUnlock()
@@ -1247,6 +1255,7 @@ func (c *KVStore) HasChannelEdge(
 		upd1Time = time.Unix(entry.upd1Time, 0)
 		upd2Time = time.Unix(entry.upd2Time, 0)
 		exists, isZombie = entry.flags.unpack()
+
 		return upd1Time, upd2Time, exists, isZombie, nil
 	}
 
@@ -1791,8 +1800,8 @@ func (c *KVStore) PruneTip() (*chainhash.Hash, uint32, error) {
 
 		// Once we have the prune tip, the value will be the block hash,
 		// and the key the block height.
-		copy(tipHash[:], v[:])
+		copy(tipHash[:], v)
-		tipHeight = byteOrder.Uint32(k[:])
+		tipHeight = byteOrder.Uint32(k)
 
 		return nil
 	}, func() {})
@@ -1946,11 +1955,12 @@ func (c *KVStore) HighestChanID() (uint64, error) {
 		// Otherwise, we'll de serialize the channel ID and return it
 		// to the caller.
 		cid = byteOrder.Uint64(lastChanID)
+
 		return nil
 	}, func() {
 		cid = 0
 	})
-	if err != nil && err != ErrGraphNoEdgesFound {
+	if err != nil && !errors.Is(err, ErrGraphNoEdgesFound) {
 		return 0, err
 	}
 
@@ -2035,7 +2045,6 @@ func (c *KVStore) ChanUpdatesInHorizon(startTime,
 		//nolint:ll
 		for indexKey, _ := updateCursor.Seek(startTimeBytes[:]); indexKey != nil &&
 			bytes.Compare(indexKey, endTimeBytes[:]) <= 0; indexKey, _ = updateCursor.Next() {
-
 			// We have a new eligible entry, so we'll slice of the
 			// chan ID so we can query it in the DB.
 			chanID := indexKey[8:]
@@ -2052,6 +2061,7 @@ func (c *KVStore) ChanUpdatesInHorizon(startTime,
 				hits++
 				edgesSeen[chanIDInt] = struct{}{}
 				edgesInHorizon = append(edgesInHorizon, channel)
+
 				continue
 			}
 
@@ -2110,9 +2120,9 @@ func (c *KVStore) ChanUpdatesInHorizon(startTime,
 		edgesInHorizon = nil
 	})
 	switch {
-	case err == ErrGraphNoEdgesFound:
+	case errors.Is(err, ErrGraphNoEdgesFound):
 		fallthrough
-	case err == ErrGraphNodesNotFound:
+	case errors.Is(err, ErrGraphNodesNotFound):
 		break
 
 	case err != nil:
@@ -2170,7 +2180,6 @@ func (c *KVStore) NodeUpdatesInHorizon(startTime,
 		//nolint:ll
 		for indexKey, _ := updateCursor.Seek(startTimeBytes[:]); indexKey != nil &&
 			bytes.Compare(indexKey, endTimeBytes[:]) <= 0; indexKey, _ = updateCursor.Next() {
-
 			nodePub := indexKey[8:]
 			node, err := fetchLightningNode(nodes, nodePub)
 			if err != nil {
@@ -2185,9 +2194,9 @@ func (c *KVStore) NodeUpdatesInHorizon(startTime,
 		nodesInHorizon = nil
 	})
 	switch {
-	case err == ErrGraphNoEdgesFound:
+	case errors.Is(err, ErrGraphNoEdgesFound):
 		fallthrough
-	case err == ErrGraphNodesNotFound:
+	case errors.Is(err, ErrGraphNodesNotFound):
 		break
 
 	case err != nil:
@@ -2294,7 +2303,7 @@ func (c *KVStore) FilterKnownChanIDs(chansInfo []ChannelUpdateInfo,
 	switch {
 	// If we don't know of any edges yet, then we'll return the entire set
 	// of chan IDs specified.
-	case err == ErrGraphNoEdgesFound:
+	case errors.Is(err, ErrGraphNoEdgesFound):
 		ogChanIDs := make([]uint64, len(chansInfo))
 		for i, info := range chansInfo {
 			ogChanIDs[i] = info.ShortChannelID.ToUint64()
@@ -2482,7 +2491,7 @@ func (c *KVStore) FilterChannelRange(startHeight,
 	switch {
 	// If we don't know of any channels yet, then there's nothing to
 	// filter, so we'll return an empty slice.
-	case err == ErrGraphNoEdgesFound || len(channelsPerBlock) == 0:
+	case errors.Is(err, ErrGraphNoEdgesFound) || len(channelsPerBlock) == 0:
 		return nil, nil
 
 	case err != nil:
@@ -2596,6 +2605,7 @@ func (c *KVStore) fetchChanInfos(tx kvdb.RTx, chanIDs []uint64) (
 				Node2:   &node2,
 			})
 		}
+
 		return nil
 	}
 
@@ -2990,7 +3000,7 @@ func (c *KVStore) isPublic(tx kvdb.RTx, nodePub route.Vertex,
 		// Otherwise, we'll continue our search.
 		return nil
 	})
-	if err != nil && err != errDone {
+	if err != nil && !errors.Is(err, errDone) {
 		return false, err
 	}
 
@@ -3113,6 +3123,7 @@ func (c *KVStore) HasLightningNode(nodePub [33]byte) (time.Time, bool,
 
 		exists = true
 		updateTime = node.LastUpdate
+
 		return nil
 	}, func() {
 		updateTime = time.Time{}
@@ -3382,6 +3393,7 @@ func (c *KVStore) FetchChannelEdgesByOutpoint(op *wire.OutPoint) (
 
 		policy1 = e1
 		policy2 = e2
+
 		return nil
 	}, func() {
 		edgeInfo = nil
@@ -3466,6 +3478,7 @@ func (c *KVStore) FetchChannelEdgesByID(chanID uint64) (
 				NodeKey1Bytes: pubKey1,
 				NodeKey2Bytes: pubKey2,
 			}
+
 			return ErrZombieEdge
 		}
 
@@ -3487,13 +3500,14 @@ func (c *KVStore) FetchChannelEdgesByID(chanID uint64) (
 
 		policy1 = e1
 		policy2 = e2
+
 		return nil
 	}, func() {
 		edgeInfo = nil
 		policy1 = nil
 		policy2 = nil
 	})
-	if err == ErrZombieEdge {
+	if errors.Is(err, ErrZombieEdge) {
 		return edgeInfo, nil, nil, err
 	}
 	if err != nil {
@@ -3523,6 +3537,7 @@ func (c *KVStore) IsPublicNode(pubKey [33]byte) (bool, error) {
 		}
 
 		nodeIsPublic, err = c.isPublic(tx, node.PubKeyBytes, ourPubKey)
+
 		return err
 	}, func() {
 		nodeIsPublic = false
@@ -3783,6 +3798,7 @@ func (c *KVStore) IsZombieEdge(chanID uint64) (bool, [33]byte, [33]byte) {
 		}
 
 		isZombie, pubKey1, pubKey2 = isZombieEdge(zombieIndex, chanID)
+
 		return nil
 	}, func() {
 		isZombie = false
@@ -3936,8 +3952,8 @@ func (c *nodeTraverserSession) FetchNodeFeatures(nodePub route.Vertex) (
 	return c.db.fetchNodeFeatures(c.tx, nodePub)
 }
 
-func putLightningNode(nodeBucket kvdb.RwBucket, aliasBucket kvdb.RwBucket, // nolint:dupl
+func putLightningNode(nodeBucket, aliasBucket, updateIndex kvdb.RwBucket,
-	updateIndex kvdb.RwBucket, node *models.LightningNode) error {
+	node *models.LightningNode) error {
 
 	var (
 		scratch [16]byte
@@ -4074,6 +4090,7 @@ func fetchLightningNode(nodeBucket kvdb.RBucket,
 	}
 
 	nodeReader := bytes.NewReader(nodeBytes)
+
 	return deserializeLightningNode(nodeReader)
 }
 
@@ -4219,8 +4236,8 @@ func deserializeLightningNode(r io.Reader) (models.LightningNode, error) {
 		r, 0, MaxAllowedExtraOpaqueBytes, "blob",
 	)
 	switch {
-	case err == io.ErrUnexpectedEOF:
+	case errors.Is(err, io.ErrUnexpectedEOF):
-	case err == io.EOF:
+	case errors.Is(err, io.EOF):
 	case err != nil:
 		return models.LightningNode{}, err
 	}
@@ -4306,6 +4323,7 @@ func fetchChanEdgeInfo(edgeIndex kvdb.RBucket,
 	}
 
 	edgeInfoReader := bytes.NewReader(edgeInfoBytes)
+
 	return deserializeChanEdgeInfo(edgeInfoReader)
 }
 
@@ -4377,8 +4395,8 @@ func deserializeChanEdgeInfo(r io.Reader) (models.ChannelEdgeInfo, error) {
 		r, 0, MaxAllowedExtraOpaqueBytes, "blob",
 	)
 	switch {
-	case err == io.ErrUnexpectedEOF:
+	case errors.Is(err, io.ErrUnexpectedEOF):
-	case err == io.EOF:
+	case errors.Is(err, io.EOF):
 	case err != nil:
 		return models.ChannelEdgeInfo{}, err
 	}
@@ -4415,7 +4433,7 @@ func putChanEdgePolicy(edges kvdb.RwBucket, edge *models.ChannelEdgePolicy,
 	// An unknown policy value does not have a update time recorded, so
 	// it also does not need to be removed.
 	if edgeBytes := edges.Get(edgeKey[:]); edgeBytes != nil &&
-		!bytes.Equal(edgeBytes[:], unknownPolicy) {
+		!bytes.Equal(edgeBytes, unknownPolicy) {
 
 		// In order to delete the old entry, we'll need to obtain the
 		// *prior* update time in order to delete it. To do this, we'll
@@ -4429,7 +4447,9 @@ func putChanEdgePolicy(edges kvdb.RwBucket, edge *models.ChannelEdgePolicy,
 		oldEdgePolicy, err := deserializeChanEdgePolicy(
 			bytes.NewReader(edgeBytes),
 		)
-		if err != nil && err != ErrEdgePolicyOptionalFieldNotFound {
+		if err != nil &&
+			!errors.Is(err, ErrEdgePolicyOptionalFieldNotFound) {
+
 			return err
 		}
 
@@ -4457,7 +4477,7 @@ func putChanEdgePolicy(edges kvdb.RwBucket, edge *models.ChannelEdgePolicy,
 		return err
 	}
 
-	return edges.Put(edgeKey[:], b.Bytes()[:])
+	return edges.Put(edgeKey[:], b.Bytes())
 }
 
 // updateEdgePolicyDisabledIndex is used to update the disabledEdgePolicyIndex
@@ -4514,7 +4534,7 @@ func fetchChanEdgePolicy(edges kvdb.RBucket, chanID []byte,
 
 	var edgeKey [33 + 8]byte
 	copy(edgeKey[:], nodePub)
-	copy(edgeKey[33:], chanID[:])
+	copy(edgeKey[33:], chanID)
 
 	edgeBytes := edges.Get(edgeKey[:])
 	if edgeBytes == nil {
@@ -4522,7 +4542,7 @@ func fetchChanEdgePolicy(edges kvdb.RBucket, chanID []byte,
 	}
 
 	// No need to deserialize unknown policy.
-	if bytes.Equal(edgeBytes[:], unknownPolicy) {
+	if bytes.Equal(edgeBytes, unknownPolicy) {
 		return nil, nil
 	}
 
@@ -4532,7 +4552,7 @@ func fetchChanEdgePolicy(edges kvdb.RBucket, chanID []byte,
 	switch {
 	// If the db policy was missing an expected optional field, we return
 	// nil as if the policy was unknown.
-	case err == ErrEdgePolicyOptionalFieldNotFound:
+	case errors.Is(err, ErrEdgePolicyOptionalFieldNotFound):
 		return nil, nil
 
 	case err != nil:
@@ -4642,6 +4662,7 @@ func serializeChanEdgePolicy(w io.Writer, edge *models.ChannelEdgePolicy,
 	if err := wire.WriteVarBytes(w, 0, opaqueBuf.Bytes()); err != nil {
 		return err
 	}
+
 	return nil
 }
 
@@ -4650,7 +4671,7 @@ func deserializeChanEdgePolicy(r io.Reader) (*models.ChannelEdgePolicy, error) {
 	// found, both an error and a populated policy object are returned.
 	edge, deserializeErr := deserializeChanEdgePolicyRaw(r)
 	if deserializeErr != nil &&
-		deserializeErr != ErrEdgePolicyOptionalFieldNotFound {
+		!errors.Is(deserializeErr, ErrEdgePolicyOptionalFieldNotFound) {
 
 		return nil, deserializeErr
 	}
@@ -4716,8 +4737,8 @@ func deserializeChanEdgePolicyRaw(r io.Reader) (*models.ChannelEdgePolicy,
 		r, 0, MaxAllowedExtraOpaqueBytes, "blob",
 	)
 	switch {
-	case err == io.ErrUnexpectedEOF:
+	case errors.Is(err, io.ErrUnexpectedEOF):
-	case err == io.EOF:
+	case errors.Is(err, io.EOF):
 	case err != nil:
 		return nil, err
 	}
@@ -4818,12 +4839,14 @@ func MakeTestGraph(t testing.TB, modifiers ...OptionModifier) (*ChannelGraph,
 	backend, backendCleanup, err := kvdb.GetTestBackend(t.TempDir(), "cgr")
 	if err != nil {
 		backendCleanup()
+
 		return nil, err
 	}
 
 	graph, err := NewChannelGraph(backend)
 	if err != nil {
 		backendCleanup()
+
 		return nil, err
 	}