chrome/renderer/weak_v8_function_map.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/logging.h"
   6 #include "chrome/renderer/weak_v8_function_map.h"
   7
   8 // Extra data to be passed to MakeWeak/RemoveFromMap to know which entry
   9 // to remove from which map.
  10 struct WeakV8FunctionMapData {
  11   base::WeakPtr<WeakV8FunctionMap> map;
  12   int key;
  13 };
  14
  15 // Disposes of a callback function and its corresponding entry in the callback
  16 // map, if that callback map is still alive.
  17 static void RemoveFromMap(v8::Persistent<v8::Value> context,
  18                                   void* data) {
  19   WeakV8FunctionMapData* map_data =
  20       static_cast<WeakV8FunctionMapData*>(data);
  21   if (map_data->map)
  22     map_data->map->Remove(map_data->key);
  23   delete map_data;
  24   context.Dispose();
  25 }
  26
  27 WeakV8FunctionMap::WeakV8FunctionMap()
  28     : ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)) {}
  29
  30 WeakV8FunctionMap::~WeakV8FunctionMap() {}
  31
  32
  33 void WeakV8FunctionMap::Add(int key,
  34                             v8::Local<v8::Function> callback_function) {
  35   WeakV8FunctionMapData* map_data = new WeakV8FunctionMapData();
  36   map_data->key = key;
  37   map_data->map = weak_ptr_factory_.GetWeakPtr();
  38   v8::Persistent<v8::Function> wrapper =
  39       v8::Persistent<v8::Function>::New(callback_function);
  40   map_[key] = wrapper;
  41   wrapper.MakeWeak(map_data, RemoveFromMap);
  42 }
  43
  44 v8::Persistent<v8::Function> WeakV8FunctionMap::Remove(int key) {
  45   WeakV8FunctionMap::Map::iterator i = map_.find(key);
  46   if (i == map_.end())
  47     return v8::Persistent<v8::Function>();
  48   v8::Persistent<v8::Function> callback = i->second;
  49   map_.erase(i);
  50   return callback;
  51 }