js/public/WeakMapPtr.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=8 sts=4 et sw=4 tw=99:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef js_WeakMapPtr_h
   8 #define js_WeakMapPtr_h
   9
  10 #include "jspubtd.h"
  11
  12 #include "js/TypeDecls.h"
  13
  14 namespace JS {
  15
  16 // A wrapper around the internal C++ representation of SpiderMonkey WeakMaps,
  17 // usable outside the engine.
  18 //
  19 // The supported template specializations are enumerated in WeakMapPtr.cpp. If
  20 // you want to use this class for a different key/value combination, add it to
  21 // the list and the compiler will generate the relevant machinery.
  22 template <typename K, typename V>
  23 class JS_PUBLIC_API(WeakMapPtr)
  24 {
  25   public:
  26     WeakMapPtr() : ptr(nullptr) {}
  27     bool init(JSContext* cx);
  28     bool initialized() { return ptr != nullptr; }
  29     void destroy();
  30     virtual ~WeakMapPtr() { MOZ_ASSERT(!initialized()); }
  31     void trace(JSTracer* tracer);
  32
  33     V lookup(const K& key);
  34     bool put(JSContext* cx, const K& key, const V& value);
  35
  36     static void keyMarkCallback(JSTracer* trc, K key, void* data);
  37
  38   private:
  39     void* ptr;
  40
  41     // WeakMapPtr is neither copyable nor assignable.
  42     WeakMapPtr(const WeakMapPtr& wmp) = delete;
  43     WeakMapPtr& operator=(const WeakMapPtr& wmp) = delete;
  44 };
  45
  46 } /* namespace JS */
  47
  48 #endif  /* js_WeakMapPtr_h */