Method ApplyMutationInternal

tensorflow/core/grappler/utils/graph_view.cc:1626–1688

}

Status MutableGraphView::ApplyMutationInternal() {
  // Node name -> node index mapping. If a node index is -1, the associated node
  // with key node name exists. Otherwise the node index is the node's index in
  // the graph.
  absl::flat_hash_map<absl::string_view, int> node_names;
  // Indices of MutableNodeViewDiff in Mutation::updated_nodes_ where nodes are
  // renamed (and possibly have other fields mutated).
  std::vector<RenamedOrOverwrittenNode> renamed_nodes;
  // Indices of MutableNodeViewDiff in Mutation::updated_nodes_ where nodes are
  // not renamed but have fields mutated.
  std::vector<int> inplace_nodes;
  // Indices of nodes in graph where MutableNodeViewDiff are empty.
  // `update_index_` of nodes associated to empty MutableNodeViewDiff should be
  // cleared after validation success.
  std::vector<int> empty_diff_node_indices;

  // Check if this mutation is valid before applying, and partition
  // updated_nodes_ into inplace mutated nodes and renamed nodes.
  TF_RETURN_IF_ERROR(ValidateInternal(
      &node_names, &renamed_nodes, &inplace_nodes, &empty_diff_node_indices));

  // Clear `update_index_` of MutableNodeView with empty associated
  // MutableNodeViewDiff.
  for (const int empty_diff_node_index : empty_diff_node_indices) {
    nodes_[empty_diff_node_index].update_index_ = internal::kMissingIndex;
  }

  // Node name and associated fanouts.
  absl::flat_hash_map<string, NodeViewFanouts> renamed_fanouts;
  // Removed nodes where name was overwritten by a renamed node.
  std::vector<bool> overwritten_name_removed_nodes(nodes_.size());
  // Fix renaming of existing nodes by swapping fanouts and rehashing names.
  // This will also overwrite removed or unmodified nodes.
  FixRenamedNodes(&renamed_nodes, &renamed_fanouts,
                  &overwritten_name_removed_nodes);

  // Indices of nodes in graph where new nodes were inserted/appended. These
  // will be corresponding to `new_nodes_` in order.
  std::vector<int> new_node_indices;
  // Add new nodes, overwriting removed or unmodified nodes.
  AddNewNodes(&renamed_fanouts, &new_node_indices);

  // For abandoned fanouts, mark their respective fanins so the original node
  // associated will not have their fanouts removed and be left in an
  // inconsistent state.
  FixRenamedFanouts(renamed_fanouts);

  // Apply mutations to updated nodes (renamed nodes are treated as inplace
  // nodes as they have already been renamed). Removed nodes are ignored.
  ApplyNodeUpdates();

  // Set fanins of new nodes.
  SetNewNodesFanins(new_node_indices);

  // Remove overwritten nodes and updated nodes set to be removed.
  RemoveNodesInternal(renamed_nodes, overwritten_name_removed_nodes);

  mutation_.ResetInternal();