Function FindExcludeDuplicationNodes

tensorflow/core/graph/algorithm.cc:263–297

}

std::unordered_set<const Node*> FindExcludeDuplicationNodes(Graph* g,
    std::unordered_set<const Node*>& visited) {
  // Compute set of nodes that we need to traverse in order to reach
  // the nodes in "nodes" by performing a breadth-first search from those
  // nodes, and accumulating the visited nodes.
  std::deque<const Node*> queue;
  for (const Node* n : visited) {
    VLOG(2) << "Reverse reach init: " << n->name();
    queue.emplace_back(n);
  }
  while (!queue.empty()) {
    const Node* n = queue.front();
    queue.pop_front();
    for (const Node* in : n->in_nodes()) {
      if (visited.insert(in).second) {
        queue.emplace_back(in);
      }
    }
  }

  // Make a pass over the graph to remove nodes not in "visited"
  std::vector<Node*> all_nodes;
  all_nodes.reserve(g->num_nodes());
  for (Node* n : g->nodes()) {
    all_nodes.emplace_back(n);
  }

  std::unordered_set<const Node*> excluded;
  for (Node* n : all_nodes) {
    if (visited.count(n) == 0 && !n->IsSource() && !n->IsSink()) {
      excluded.emplace(n);
    }
  }
  return excluded;
}

}  // namespace tensorflow