much faster deserialize (#422)

src/ngraph/serializer.cpp

@@ -308,12 +308,6 @@ static shared_ptr<ngraph::Function>
             args.push_back(node_map.at(name));
         }
 
-        vector<string> known_nodes;
-        for (auto x : node_map)
-        {
-            known_nodes.push_back(x.first);
-        }
-
         if (node_op == "Abs")
         {
             node = make_shared<op::Abs>(args[0]);

test/serialize.cpp

@@ -99,7 +99,22 @@ TEST(serialize, existing_models)
     {
         const string json_path = file_util::path_join(SERIALIZED_ZOO, model);
         const string json_string = file_util::read_file_to_string(json_path);
-        stringstream ss(json_string);
-        shared_ptr<Function> f = ngraph::deserialize(ss);
+        shared_ptr<Function> f = ngraph::deserialize(json_string);
     }
 }
+
+TEST(benchmark, serialize)
+{
+    stopwatch timer;
+    string model = "mxnet/LSTM_backward.json";
+
+    const string json_path = file_util::path_join(SERIALIZED_ZOO, model);
+    timer.start();
+    const string json_string = file_util::read_file_to_string(json_path);
+    timer.stop();
+    cout << "file read took " << timer.get_milliseconds() << "ms\n";
+    timer.start();
+    shared_ptr<Function> f = ngraph::deserialize(json_string);
+    timer.stop();
+    cout << "deserialize took " << timer.get_milliseconds() << "ms\n";
+}