1 files changed, 72 insertions, 0 deletions
diff --git a/tensorflow/core/grappler/mutable_graph_view.cc b/tensorflow/core/grappler/mutable_graph_view.cc
new file mode 100644
index 0000000000..6abafe11a2
--- /dev/null
+++ b/tensorflow/core/grappler/mutable_graph_view.cc
@@ -0,0 +1,72 @@
+/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#include "tensorflow/core/grappler/mutable_graph_view.h"
+#include "tensorflow/core/grappler/utils.h"
+
+namespace tensorflow {
+namespace grappler {
+
+NodeDef* MutableGraphView::AddNode(NodeDef&& node) {
+  auto* node_in_graph = GetGraph()->add_node();
+  *node_in_graph = std::move(node);
+
+  auto result = MutableNodes()->emplace(node_in_graph->name(), node_in_graph);
+  // Check that the graph doesn't contain multiple nodes with the same name.
+  CHECK(result.second) << "Non unique node name detected: "
+                       << node_in_graph->name();
+  AddFanouts(node_in_graph);
+  return node_in_graph;
+}
+
+void MutableGraphView::ReplaceInput(const NodeDef& old_input,
+                                    const NodeDef& new_input,
+                                    const int output_port_id) {
+  GraphView::OutputPort output_port =
+      GetOutputPort(old_input.name(), output_port_id);
+  auto fanout = GetFanout(output_port);
+  for (auto& input_port : fanout) {
+    input_port.node->set_input(input_port.port_id, new_input.name());
+    AddFanouts(input_port.node);
+  }
+}
+
+void MutableGraphView::DeleteNodes(const std::set<string>& nodes_to_delete) {
+  for (const string& node_name_to_delete : nodes_to_delete)
+    RemoveFanouts(MutableNodes()->at(node_name_to_delete));
+  for (const string& node_name_to_delete : nodes_to_delete)
+    MutableNodes()->erase(node_name_to_delete);
+  EraseNodesFromGraph(nodes_to_delete, GetGraph());
+}
+
+void MutableGraphView::RemoveFanouts(NodeDef* node) {
+  for (int i = 0; i < node->input_size(); ++i) {
+    OutputPort fanin;
+    string fanin_name = ParseNodeName(node->input(i), &fanin.port_id);
+    fanin.node = (*MutableNodes())[fanin_name];
+
+    InputPort input;
+    input.node = node;
+    if (fanin.port_id < 0)
+      input.port_id = -1;
+    else
+      input.port_id = i;
+
+    (*MutableFanouts())[fanin].erase(input);
+  }
+}
+
+}  // end namespace grappler
+}  // end namespace tensorflow