netann+lnd: add netann.ChannelGraph to the GraphSource interface

And let DBSource implement it.

netann/chan_status_manager.go

@@ -1,6 +1,7 @@
 package netann
 
 import (
+	"context"
 	"errors"
 	"sync"
 	"time"
@@ -653,8 +654,12 @@ func (m *ChanStatusManager) signAndSendNextUpdate(outpoint wire.OutPoint,
 func (m *ChanStatusManager) fetchLastChanUpdateByOutPoint(op wire.OutPoint) (
 	*lnwire.ChannelUpdate1, bool, error) {
 
+	ctx := context.TODO()
+
 	// Get the edge info and policies for this channel from the graph.
-	info, edge1, edge2, err := m.cfg.Graph.FetchChannelEdgesByOutpoint(&op)
+	info, edge1, edge2, err := m.cfg.Graph.FetchChannelEdgesByOutpoint(
+		ctx, &op,
+	)
 	if err != nil {
 		return nil, false, err
 	}

netann/chan_status_manager_test.go

@@ -2,6 +2,7 @@ package netann_test
 
 import (
 	"bytes"
+	"context"
 	"crypto/rand"
 	"encoding/binary"
 	"fmt"
@@ -160,7 +161,7 @@ func (g *mockGraph) FetchAllOpenChannels() ([]*channeldb.OpenChannel, error) {
 	return g.chans(), nil
 }
 
-func (g *mockGraph) FetchChannelEdgesByOutpoint(
+func (g *mockGraph) FetchChannelEdgesByOutpoint(ctx context.Context,
 	op *wire.OutPoint) (*models.ChannelEdgeInfo,
 	*models.ChannelEdgePolicy, *models.ChannelEdgePolicy, error) {
 

netann/interface.go

@@ -1,6 +1,8 @@
 package netann
 
 import (
+	"context"
+
 	"github.com/btcsuite/btcd/wire"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/graph/db/models"
@@ -19,6 +21,7 @@ type DB interface {
 type ChannelGraph interface {
 	// FetchChannelEdgesByOutpoint returns the channel edge info and most
 	// recent channel edge policies for a given outpoint.
-	FetchChannelEdgesByOutpoint(*wire.OutPoint) (*models.ChannelEdgeInfo,
-		*models.ChannelEdgePolicy, *models.ChannelEdgePolicy, error)
+	FetchChannelEdgesByOutpoint(context.Context, *wire.OutPoint) (
+		*models.ChannelEdgeInfo, *models.ChannelEdgePolicy,
+		*models.ChannelEdgePolicy, error)
 }