1 files changed, 16 insertions, 4 deletions
diff --git a/tensorflow/core/grappler/graph_view.h b/tensorflow/core/grappler/graph_view.h
index 584cb9048b..050789d2e2 100644
--- a/tensorflow/core/grappler/graph_view.h
+++ b/tensorflow/core/grappler/graph_view.h
@@ -29,8 +29,11 @@ namespace grappler {
 class GraphView {
  public:
   struct Port {
-    Port() : node(nullptr), port_id(-1) {}
+    Port() = default;
     Port(NodeDef* n, int port) : node(n), port_id(port) {}
+
+    // TODO(prazek): ports should keep the constness of GraphView.  The only way
+    // to modify graph through the view should be using MutableGraphView.
     NodeDef* node = nullptr;
     int port_id = -1;
 
@@ -111,13 +114,22 @@ class GraphView {
   std::unordered_set<Edge, HashEdge> GetFaninEdges(
       const NodeDef& node, bool include_controlling_edges) const;
 
+ protected:
+  // Add fanout to every `node` input.
+  void AddFanouts(NodeDef* node);
+  std::unordered_map<string, NodeDef*>* MutableNodes() { return &nodes_; }
+  GraphDef* MutableGraph() { return graph_; }
+
+  using FanoutsMapType =
+      std::unordered_map<OutputPort, std::unordered_set<InputPort, HashPort>,
+                         HashPort>;
+  FanoutsMapType* MutableFanouts() { return &fanouts_; }
+
  private:
   GraphDef* graph_;
   std::unordered_map<string, NodeDef*> nodes_;
   std::unordered_set<InputPort, HashPort> empty_set_;
-  std::unordered_map<OutputPort, std::unordered_set<InputPort, HashPort>,
-                     HashPort>
-      fanouts_;
+  FanoutsMapType fanouts_;
   std::unordered_map<const NodeDef*, int> num_regular_outputs_;
 };