Added a config class to ease passing a set of options across webrtc.

Its main design reason is to expose control of experimental webrtc features.

R=niklas.enbom@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1450009

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4004 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/common_unittest.cc

@@ -0,0 +1,77 @@
+/*
+ *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "common.h"  // NOLINT
+
+#include "gtest/gtest.h"
+
+namespace webrtc {
+namespace {
+
+struct MyExperiment {
+  enum { kDefaultFactor = 1 };
+  enum { kDefaultOffset = 2 };
+
+  MyExperiment()
+    : factor(kDefaultFactor), offset(kDefaultOffset) {}
+
+  MyExperiment(int factor, int offset)
+    : factor(factor), offset(offset) {}
+
+  int factor;
+  int offset;
+};
+
+TEST(Config, ReturnsDefaultInstanceIfNotConfigured) {
+  Config config;
+  const MyExperiment& my_exp = config.Get<MyExperiment>();
+  EXPECT_EQ(MyExperiment::kDefaultFactor, my_exp.factor);
+  EXPECT_EQ(MyExperiment::kDefaultOffset, my_exp.offset);
+}
+
+TEST(Config, ReturnOptionWhenSet) {
+  Config config;
+  config.Set<MyExperiment>(new MyExperiment(5, 1));
+  const MyExperiment& my_exp = config.Get<MyExperiment>();
+  EXPECT_EQ(5, my_exp.factor);
+  EXPECT_EQ(1, my_exp.offset);
+}
+
+TEST(Config, SetNullSetsTheOptionBackToDefault) {
+  Config config;
+  config.Set<MyExperiment>(new MyExperiment(5, 1));
+  config.Set<MyExperiment>(NULL);
+  const MyExperiment& my_exp = config.Get<MyExperiment>();
+  EXPECT_EQ(MyExperiment::kDefaultFactor, my_exp.factor);
+  EXPECT_EQ(MyExperiment::kDefaultOffset, my_exp.offset);
+}
+
+struct Algo1_CostFunction {
+  Algo1_CostFunction() {}
+
+  virtual int cost(int x) const {
+    return x;
+  }
+
+  virtual ~Algo1_CostFunction() {}
+};
+
+struct SqrCost : Algo1_CostFunction {
+  virtual int cost(int x) const {
+    return x*x;
+  }
+};
+
+TEST(Config, SupportsPolimorphism) {
+  Config config;
+  config.Set<Algo1_CostFunction>(new SqrCost());
+  EXPECT_EQ(25, config.Get<Algo1_CostFunction>().cost(5));
+}
+}  // namespace
+}  // namespace webrtc