routing+server: use cached graph interface

routing/graph.go

@@ -9,7 +9,8 @@ import (
 // routingGraph is an abstract interface that provides information about nodes
 // and edges to pathfinding.
 type routingGraph interface {
-	// forEachNodeChannel calls the callback for every channel of the given node.
+	// forEachNodeChannel calls the callback for every channel of the given
+	// node.
 	forEachNodeChannel(nodePub route.Vertex,
 		cb func(channel *channeldb.DirectedChannel) error) error
 
@@ -20,22 +21,26 @@ type routingGraph interface {
 	fetchNodeFeatures(nodePub route.Vertex) (*lnwire.FeatureVector, error)
 }
 
-// dbRoutingTx is a routingGraph implementation that retrieves from the
+// CachedGraph is a routingGraph implementation that retrieves from the
 // database.
-type dbRoutingTx struct {
+type CachedGraph struct {
 	graph  *channeldb.ChannelGraph
 	source route.Vertex
 }
 
-// newDbRoutingTx instantiates a new db-connected routing graph. It implictly
+// A compile time assertion to make sure CachedGraph implements the routingGraph
+// interface.
+var _ routingGraph = (*CachedGraph)(nil)
+
+// NewCachedGraph instantiates a new db-connected routing graph. It implictly
 // instantiates a new read transaction.
-func newDbRoutingTx(graph *channeldb.ChannelGraph) (*dbRoutingTx, error) {
+func NewCachedGraph(graph *channeldb.ChannelGraph) (*CachedGraph, error) {
 	sourceNode, err := graph.SourceNode()
 	if err != nil {
 		return nil, err
 	}
 
-	return &dbRoutingTx{
+	return &CachedGraph{
 		graph:  graph,
 		source: sourceNode.PubKeyBytes,
 	}, nil
@@ -44,7 +49,7 @@ func newDbRoutingTx(graph *channeldb.ChannelGraph) (*dbRoutingTx, error) {
 // forEachNodeChannel calls the callback for every channel of the given node.
 //
 // NOTE: Part of the routingGraph interface.
-func (g *dbRoutingTx) forEachNodeChannel(nodePub route.Vertex,
+func (g *CachedGraph) forEachNodeChannel(nodePub route.Vertex,
 	cb func(channel *channeldb.DirectedChannel) error) error {
 
 	return g.graph.ForEachNodeChannel(nodePub, cb)
@@ -53,7 +58,7 @@ func (g *dbRoutingTx) forEachNodeChannel(nodePub route.Vertex,
 // sourceNode returns the source node of the graph.
 //
 // NOTE: Part of the routingGraph interface.
-func (g *dbRoutingTx) sourceNode() route.Vertex {
+func (g *CachedGraph) sourceNode() route.Vertex {
 	return g.source
 }
 
@@ -61,7 +66,7 @@ func (g *dbRoutingTx) sourceNode() route.Vertex {
 // unknown, assume no additional features are supported.
 //
 // NOTE: Part of the routingGraph interface.
-func (g *dbRoutingTx) fetchNodeFeatures(nodePub route.Vertex) (
+func (g *CachedGraph) fetchNodeFeatures(nodePub route.Vertex) (
 	*lnwire.FeatureVector, error) {
 
 	return g.graph.FetchNodeFeatures(nodePub)

routing/integrated_routing_context_test.go

@@ -162,11 +162,7 @@ func (c *integratedRoutingContext) testPayment(maxParts uint32,
 	}
 
 	session, err := newPaymentSession(
-		&payment, getBandwidthHints,
-		func() (routingGraph, func(), error) {
-			return c.graph, func() {}, nil
-		},
-		mc, c.pathFindingCfg,
+		&payment, getBandwidthHints, c.graph, mc, c.pathFindingCfg,
 	)
 	if err != nil {
 		c.t.Fatal(err)

routing/pathfind_test.go

@@ -3021,7 +3021,7 @@ func dbFindPath(graph *channeldb.ChannelGraph,
 	source, target route.Vertex, amt lnwire.MilliSatoshi,
 	finalHtlcExpiry int32) ([]*channeldb.CachedEdgePolicy, error) {
 
-	routingTx, err := newDbRoutingTx(graph)
+	routingGraph, err := NewCachedGraph(graph)
 	if err != nil {
 		return nil, err
 	}
@@ -3030,7 +3030,7 @@ func dbFindPath(graph *channeldb.ChannelGraph,
 		&graphParams{
 			additionalEdges: additionalEdges,
 			bandwidthHints:  bandwidthHints,
-			graph:           routingTx,
+			graph:           routingGraph,
 		},
 		r, cfg, source, target, amt, finalHtlcExpiry,
 	)

routing/payment_session.go

@@ -172,7 +172,7 @@ type paymentSession struct {
 
 	pathFinder pathFinder
 
-	getRoutingGraph func() (routingGraph, func(), error)
+	routingGraph routingGraph
 
 	// pathFindingConfig defines global parameters that control the
 	// trade-off in path finding between fees and probabiity.
@@ -193,7 +193,7 @@ type paymentSession struct {
 // newPaymentSession instantiates a new payment session.
 func newPaymentSession(p *LightningPayment,
 	getBandwidthHints func() (map[uint64]lnwire.MilliSatoshi, error),
-	getRoutingGraph func() (routingGraph, func(), error),
+	routingGraph routingGraph,
 	missionControl MissionController, pathFindingConfig PathFindingConfig) (
 	*paymentSession, error) {
 
@@ -209,7 +209,7 @@ func newPaymentSession(p *LightningPayment,
 		getBandwidthHints: getBandwidthHints,
 		payment:           p,
 		pathFinder:        findPath,
-		getRoutingGraph:   getRoutingGraph,
+		routingGraph:      routingGraph,
 		pathFindingConfig: pathFindingConfig,
 		missionControl:    missionControl,
 		minShardAmt:       DefaultShardMinAmt,
@@ -287,29 +287,20 @@ func (p *paymentSession) RequestRoute(maxAmt, feeLimit lnwire.MilliSatoshi,
 
 		p.log.Debugf("pathfinding for amt=%v", maxAmt)
 
-		// Get a routing graph.
-		routingGraph, cleanup, err := p.getRoutingGraph()
-		if err != nil {
-			return nil, err
-		}
-
-		sourceVertex := routingGraph.sourceNode()
+		sourceVertex := p.routingGraph.sourceNode()
 
 		// Find a route for the current amount.
 		path, err := p.pathFinder(
 			&graphParams{
 				additionalEdges: p.additionalEdges,
 				bandwidthHints:  bandwidthHints,
-				graph:           routingGraph,
+				graph:           p.routingGraph,
 			},
 			restrictions, &p.pathFindingConfig,
 			sourceVertex, p.payment.Target,
 			maxAmt, finalHtlcExpiry,
 		)
 
-		// Close routing graph.
-		cleanup()
-
 		switch {
 		case err == errNoPathFound:
 			// Don't split if this is a legacy payment without mpp

routing/payment_session_source.go

@@ -17,7 +17,7 @@ var _ PaymentSessionSource = (*SessionSource)(nil)
 type SessionSource struct {
 	// Graph is the channel graph that will be used to gather metrics from
 	// and also to carry out path finding queries.
-	Graph *channeldb.ChannelGraph
+	Graph routingGraph
 
 	// QueryBandwidth is a method that allows querying the lower link layer
 	// to determine the up to date available bandwidth at a prospective link
@@ -40,16 +40,6 @@ type SessionSource struct {
 	PathFindingConfig PathFindingConfig
 }
 
-// getRoutingGraph returns a routing graph and a clean-up function for
-// pathfinding.
-func (m *SessionSource) getRoutingGraph() (routingGraph, func(), error) {
-	routingTx, err := newDbRoutingTx(m.Graph)
-	if err != nil {
-		return nil, nil, err
-	}
-	return routingTx, func() {}, nil
-}
-
 // NewPaymentSession creates a new payment session backed by the latest prune
 // view from Mission Control. An optional set of routing hints can be provided
 // in order to populate additional edges to explore when finding a path to the
@@ -57,21 +47,16 @@ func (m *SessionSource) getRoutingGraph() (routingGraph, func(), error) {
 func (m *SessionSource) NewPaymentSession(p *LightningPayment) (
 	PaymentSession, error) {
 
-	sourceNode, err := m.Graph.SourceNode()
-	if err != nil {
-		return nil, err
-	}
-
 	getBandwidthHints := func() (map[uint64]lnwire.MilliSatoshi,
 		error) {
 
 		return generateBandwidthHints(
-			sourceNode.PubKeyBytes, m.Graph, m.QueryBandwidth,
+			m.Graph.sourceNode(), m.Graph, m.QueryBandwidth,
 		)
 	}
 
 	session, err := newPaymentSession(
-		p, getBandwidthHints, m.getRoutingGraph,
+		p, getBandwidthHints, m.Graph,
 		m.MissionControl, m.PathFindingConfig,
 	)
 	if err != nil {

routing/payment_session_test.go

@@ -121,9 +121,7 @@ func TestUpdateAdditionalEdge(t *testing.T) {
 
 			return nil, nil
 		},
-		func() (routingGraph, func(), error) {
-			return &sessionGraph{}, func() {}, nil
-		},
+		&sessionGraph{},
 		&MissionControl{},
 		PathFindingConfig{},
 	)
@@ -203,9 +201,7 @@ func TestRequestRoute(t *testing.T) {
 
 			return nil, nil
 		},
-		func() (routingGraph, func(), error) {
-			return &sessionGraph{}, func() {}, nil
-		},
+		&sessionGraph{},
 		&MissionControl{},
 		PathFindingConfig{},
 	)

routing/router.go

@@ -406,6 +406,10 @@ type ChannelRouter struct {
 	// when doing any path finding.
 	selfNode *channeldb.LightningNode
 
+	// cachedGraph is an instance of routingGraph that caches the source node as
+	// well as the channel graph itself in memory.
+	cachedGraph routingGraph
+
 	// newBlocks is a channel in which new blocks connected to the end of
 	// the main chain are sent over, and blocks updated after a call to
 	// UpdateFilter.
@@ -460,7 +464,6 @@ var _ ChannelGraphSource = (*ChannelRouter)(nil)
 // channel graph is a subset of the UTXO set) set, then the router will proceed
 // to fully sync to the latest state of the UTXO set.
 func New(cfg Config) (*ChannelRouter, error) {
-
 	selfNode, err := cfg.Graph.SourceNode()
 	if err != nil {
 		return nil, err
@@ -468,6 +471,10 @@ func New(cfg Config) (*ChannelRouter, error) {
 
 	r := &ChannelRouter{
 		cfg: &cfg,
+		cachedGraph: &CachedGraph{
+			graph:  cfg.Graph,
+			source: selfNode.PubKeyBytes,
+		},
 		networkUpdates:    make(chan *routingMsg),
 		topologyClients:   make(map[uint64]*topologyClient),
 		ntfnClientUpdates: make(chan *topologyClientUpdate),
@@ -1735,7 +1742,7 @@ func (r *ChannelRouter) FindRoute(source, target route.Vertex,
 	// We'll attempt to obtain a set of bandwidth hints that can help us
 	// eliminate certain routes early on in the path finding process.
 	bandwidthHints, err := generateBandwidthHints(
-		r.selfNode.PubKeyBytes, r.cfg.Graph, r.cfg.QueryBandwidth,
+		r.selfNode.PubKeyBytes, r.cachedGraph, r.cfg.QueryBandwidth,
 	)
 	if err != nil {
 		return nil, err
@@ -1752,16 +1759,11 @@ func (r *ChannelRouter) FindRoute(source, target route.Vertex,
 	// execute our path finding algorithm.
 	finalHtlcExpiry := currentHeight + int32(finalExpiry)
 
-	routingTx, err := newDbRoutingTx(r.cfg.Graph)
-	if err != nil {
-		return nil, err
-	}
-
 	path, err := findPath(
 		&graphParams{
 			additionalEdges: routeHints,
 			bandwidthHints:  bandwidthHints,
-			graph:           routingTx,
+			graph:           r.cachedGraph,
 		},
 		restrictions,
 		&r.cfg.PathFindingConfig,
@@ -2657,14 +2659,14 @@ func (r *ChannelRouter) MarkEdgeLive(chanID lnwire.ShortChannelID) error {
 // these hints allows us to reduce the number of extraneous attempts as we can
 // skip channels that are inactive, or just don't have enough bandwidth to
 // carry the payment.
-func generateBandwidthHints(sourceNode route.Vertex, graph *channeldb.ChannelGraph,
+func generateBandwidthHints(sourceNode route.Vertex, graph routingGraph,
 	queryBandwidth func(*channeldb.DirectedChannel) lnwire.MilliSatoshi) (
 	map[uint64]lnwire.MilliSatoshi, error) {
 
 	// First, we'll collect the set of outbound edges from the target
 	// source node.
 	var localChans []*channeldb.DirectedChannel
-	err := graph.ForEachNodeChannel(
+	err := graph.forEachNodeChannel(
 		sourceNode, func(channel *channeldb.DirectedChannel) error {
 			localChans = append(localChans, channel)
 			return nil
@@ -2722,7 +2724,7 @@ func (r *ChannelRouter) BuildRoute(amt *lnwire.MilliSatoshi,
 	// We'll attempt to obtain a set of bandwidth hints that helps us select
 	// the best outgoing channel to use in case no outgoing channel is set.
 	bandwidthHints, err := generateBandwidthHints(
-		r.selfNode.PubKeyBytes, r.cfg.Graph, r.cfg.QueryBandwidth,
+		r.selfNode.PubKeyBytes, r.cachedGraph, r.cfg.QueryBandwidth,
 	)
 	if err != nil {
 		return nil, err
@@ -2752,12 +2754,6 @@ func (r *ChannelRouter) BuildRoute(amt *lnwire.MilliSatoshi,
 		runningAmt = *amt
 	}
 
-	// Open a transaction to execute the graph queries in.
-	routingTx, err := newDbRoutingTx(r.cfg.Graph)
-	if err != nil {
-		return nil, err
-	}
-
 	// Traverse hops backwards to accumulate fees in the running amounts.
 	source := r.selfNode.PubKeyBytes
 	for i := len(hops) - 1; i >= 0; i-- {
@@ -2776,7 +2772,7 @@ func (r *ChannelRouter) BuildRoute(amt *lnwire.MilliSatoshi,
 		// known in the graph.
 		u := newUnifiedPolicies(source, toNode, outgoingChans)
 
-		err := u.addGraphPolicies(routingTx)
+		err := u.addGraphPolicies(r.cachedGraph)
 		if err != nil {
 			return nil, err
 		}

routing/router_test.go

@@ -129,8 +129,11 @@ func createTestCtxFromGraphInstanceAssumeValid(t *testing.T,
 	)
 	require.NoError(t, err, "failed to create missioncontrol")
 
+	cachedGraph, err := NewCachedGraph(graphInstance.graph)
+	require.NoError(t, err)
+
 	sessionSource := &SessionSource{
-		Graph: graphInstance.graph,
+		Graph: cachedGraph,
 		QueryBandwidth: func(
 			c *channeldb.DirectedChannel) lnwire.MilliSatoshi {
 

server.go

@@ -776,8 +776,12 @@ func newServer(cfg *Config, listenAddrs []net.Addr,
 		MinProbability: routingConfig.MinRouteProbability,
 	}
 
+	cachedGraph, err := routing.NewCachedGraph(chanGraph)
+	if err != nil {
+		return nil, err
+	}
 	paymentSessionSource := &routing.SessionSource{
-		Graph:             chanGraph,
+		Graph:             cachedGraph,
 		MissionControl:    s.missionControl,
 		QueryBandwidth:    queryBandwidth,
 		PathFindingConfig: pathFindingConfig,