invoicesrpc: remove direct access to ChannelGraph pointer

lnrpc/invoicesrpc/interfaces.go

@@ -0,0 +1,19 @@
+package invoicesrpc
+
+import (
+	"github.com/lightningnetwork/lnd/graph/db/models"
+)
+
+// GraphSource defines the graph interface required by the invoice rpc server.
+type GraphSource interface {
+	// FetchChannelEdgesByID attempts to look up the two directed edges for
+	// the channel identified by the channel ID. If the channel can't be
+	// found, then graphdb.ErrEdgeNotFound is returned.
+	FetchChannelEdgesByID(chanID uint64) (*models.ChannelEdgeInfo,
+		*models.ChannelEdgePolicy, *models.ChannelEdgePolicy, error)
+
+	// IsPublicNode is a helper method that determines whether the node with
+	// the given public key is seen as a public node in the graph from the
+	// graph's source node's point of view.
+	IsPublicNode(pubKey [33]byte) (bool, error)
+}