Add ScopedDeque (similar to the existing ScopedVector).

base/memory/scoped_deque_unittest.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_deque.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+// The LifeCycleObject notifies its Observer upon construction & destruction.
+class LifeCycleObject {
+ public:
+  class Observer {
+   public:
+    virtual void OnLifeCycleConstruct(LifeCycleObject* o) = 0;
+    virtual void OnLifeCycleDestroy(LifeCycleObject* o) = 0;
+
+   protected:
+    virtual ~Observer() {}
+  };
+
+  explicit LifeCycleObject(Observer* observer)
+      : observer_(observer) {
+    observer_->OnLifeCycleConstruct(this);
+  }
+
+  ~LifeCycleObject() {
+    observer_->OnLifeCycleDestroy(this);
+  }
+
+ private:
+  Observer* observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(LifeCycleObject);
+};
+
+// The life cycle states we care about for the purposes of testing ScopedVector
+// against objects.
+enum LifeCycleState {
+  LC_INITIAL,
+  LC_CONSTRUCTED,
+  LC_DESTROYED,
+};
+
+// Because we wish to watch the life cycle of an object being constructed and
+// destroyed, and further wish to test expectations against the state of that
+// object, we cannot save state in that object itself. Instead, we use this
+// pairing of the watcher, which observes the object and notifies of
+// construction & destruction. Since we also may be testing assumptions about
+// things not getting freed, this class also acts like a scoping object and
+// deletes the |constructed_life_cycle_object_|, if any when the
+// LifeCycleWatcher is destroyed. To keep this simple, the only expected state
+// changes are:
+//   INITIAL -> CONSTRUCTED -> DESTROYED.
+// Anything more complicated than that should start another test.
+class LifeCycleWatcher : public LifeCycleObject::Observer {
+ public:
+  LifeCycleWatcher()
+      : life_cycle_state_(LC_INITIAL),
+        constructed_life_cycle_object_(NULL) {}
+  ~LifeCycleWatcher() {
+  }
+
+  // Assert INITIAL -> CONSTRUCTED and no LifeCycleObject associated with this
+  // LifeCycleWatcher.
+  virtual void OnLifeCycleConstruct(LifeCycleObject* object) {
+    ASSERT_EQ(LC_INITIAL, life_cycle_state_);
+    ASSERT_EQ(NULL, constructed_life_cycle_object_.get());
+    life_cycle_state_ = LC_CONSTRUCTED;
+    constructed_life_cycle_object_.reset(object);
+  }
+
+  // Assert CONSTRUCTED -> DESTROYED and the |object| being destroyed is the
+  // same one we saw constructed.
+  virtual void OnLifeCycleDestroy(LifeCycleObject* object) {
+    ASSERT_EQ(LC_CONSTRUCTED, life_cycle_state_);
+    LifeCycleObject* constructed_life_cycle_object =
+        constructed_life_cycle_object_.release();
+    ASSERT_EQ(constructed_life_cycle_object, object);
+    life_cycle_state_ = LC_DESTROYED;
+  }
+
+  LifeCycleState life_cycle_state() const { return life_cycle_state_; }
+
+  // Factory method for creating a new LifeCycleObject tied to this
+  // LifeCycleWatcher.
+  LifeCycleObject* NewLifeCycleObject() {
+    return new LifeCycleObject(this);
+  }
+
+ private:
+  LifeCycleState life_cycle_state_;
+  scoped_ptr<LifeCycleObject> constructed_life_cycle_object_;
+
+  DISALLOW_COPY_AND_ASSIGN(LifeCycleWatcher);
+};
+
+TEST(ScopedDequeTest, LifeCycleWatcher) {
+  LifeCycleWatcher watcher;
+  EXPECT_EQ(LC_INITIAL, watcher.life_cycle_state());
+  LifeCycleObject* object = watcher.NewLifeCycleObject();
+  EXPECT_EQ(LC_CONSTRUCTED, watcher.life_cycle_state());
+  delete object;
+  EXPECT_EQ(LC_DESTROYED, watcher.life_cycle_state());
+}
+
+TEST(ScopedDequeTest, Clear) {
+  LifeCycleWatcher watcher;
+  EXPECT_EQ(LC_INITIAL, watcher.life_cycle_state());
+  ScopedDeque<LifeCycleObject> scoped_deque;
+  scoped_deque.push_back(watcher.NewLifeCycleObject());
+  EXPECT_EQ(LC_CONSTRUCTED, watcher.life_cycle_state());
+  scoped_deque.clear();
+  EXPECT_EQ(LC_DESTROYED, watcher.life_cycle_state());
+  EXPECT_TRUE(scoped_deque.empty());
+}
+
+TEST(ScopedDequeTest, PopFront) {
+  LifeCycleWatcher watcher;
+  EXPECT_EQ(LC_INITIAL, watcher.life_cycle_state());
+  ScopedDeque<LifeCycleObject> scoped_deque;
+  scoped_deque.push_back(watcher.NewLifeCycleObject());
+  EXPECT_EQ(LC_CONSTRUCTED, watcher.life_cycle_state());
+  scoped_deque.pop_front();
+  EXPECT_EQ(LC_DESTROYED, watcher.life_cycle_state());
+  EXPECT_TRUE(scoped_deque.empty());
+}
+
+TEST(ScopedDequeTest, PopBack) {
+  LifeCycleWatcher watcher;
+  EXPECT_EQ(LC_INITIAL, watcher.life_cycle_state());
+  ScopedDeque<LifeCycleObject> scoped_deque;
+  scoped_deque.push_back(watcher.NewLifeCycleObject());
+  EXPECT_EQ(LC_CONSTRUCTED, watcher.life_cycle_state());
+  scoped_deque.pop_back();
+  EXPECT_EQ(LC_DESTROYED, watcher.life_cycle_state());
+  EXPECT_TRUE(scoped_deque.empty());
+}
+
+TEST(ScopedDequeTest, Scope) {
+  LifeCycleWatcher watcher;
+  EXPECT_EQ(LC_INITIAL, watcher.life_cycle_state());
+  {
+    ScopedDeque<LifeCycleObject> scoped_deque;
+    scoped_deque.push_back(watcher.NewLifeCycleObject());
+    EXPECT_EQ(LC_CONSTRUCTED, watcher.life_cycle_state());
+  }
+  EXPECT_EQ(LC_DESTROYED, watcher.life_cycle_state());
+}
+
+TEST(ScopedDequeTest, InsertRange) {
+  LifeCycleWatcher watchers[5];
+
+  std::deque<LifeCycleObject*> vec;
+  for(LifeCycleWatcher* it = watchers; it != watchers + arraysize(watchers);
+      ++it) {
+    EXPECT_EQ(LC_INITIAL, it->life_cycle_state());
+    vec.push_back(it->NewLifeCycleObject());
+    EXPECT_EQ(LC_CONSTRUCTED, it->life_cycle_state());
+  }
+  // Start scope for ScopedDeque.
+  {
+    ScopedDeque<LifeCycleObject> scoped_deque;
+    scoped_deque.insert(scoped_deque.end(), vec.begin() + 1, vec.begin() + 3);
+    for(LifeCycleWatcher* it = watchers; it != watchers + arraysize(watchers);
+        ++it)
+      EXPECT_EQ(LC_CONSTRUCTED, it->life_cycle_state());
+  }
+  for(LifeCycleWatcher* it = watchers; it != watchers + 1; ++it)
+    EXPECT_EQ(LC_CONSTRUCTED, it->life_cycle_state());
+  for(LifeCycleWatcher* it = watchers + 1; it != watchers + 3; ++it)
+    EXPECT_EQ(LC_DESTROYED, it->life_cycle_state());
+  for(LifeCycleWatcher* it = watchers + 3; it != watchers + arraysize(watchers);
+      ++it)
+    EXPECT_EQ(LC_CONSTRUCTED, it->life_cycle_state());
+}
+
+}  // namespace