michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
michael@0:  * vim: set ts=8 sts=4 et sw=4 tw=99:
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "js/WeakMapPtr.h"
michael@0: 
michael@0: #include "jsweakmap.h"
michael@0: 
michael@0: //
michael@0: // Machinery for the externally-linkable JS::WeakMapPtr, which wraps js::WeakMap
michael@0: // for a few public data types.
michael@0: //
michael@0: 
michael@0: using namespace js;
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: template<typename T>
michael@0: struct DataType
michael@0: {
michael@0: };
michael@0: 
michael@0: template<>
michael@0: struct DataType<JSObject*>
michael@0: {
michael@0:     typedef EncapsulatedPtrObject Encapsulated;
michael@0:     static JSObject *NullValue() { return nullptr; }
michael@0: };
michael@0: 
michael@0: template<>
michael@0: struct DataType<JS::Value>
michael@0: {
michael@0:     typedef EncapsulatedValue Encapsulated;
michael@0:     static JS::Value NullValue() { return JS::UndefinedValue(); }
michael@0: };
michael@0: 
michael@0: template <typename K, typename V>
michael@0: struct Utils
michael@0: {
michael@0:     typedef typename DataType<K>::Encapsulated KeyType;
michael@0:     typedef typename DataType<V>::Encapsulated ValueType;
michael@0:     typedef WeakMap<KeyType, ValueType> Type;
michael@0:     typedef Type* PtrType;
michael@0:     static PtrType cast(void *ptr) { return static_cast<PtrType>(ptr); }
michael@0: };
michael@0: 
michael@0: } /* namespace */
michael@0: 
michael@0: template <typename K, typename V>
michael@0: void
michael@0: JS::WeakMapPtr<K, V>::destroy()
michael@0: {
michael@0:     MOZ_ASSERT(initialized());
michael@0:     auto map = Utils<K, V>::cast(ptr);
michael@0:     // If this destruction happens mid-GC, we might be in the compartment's list
michael@0:     // of known live weakmaps. If we are, remove ourselves before deleting.
michael@0:     if (map->isInList())
michael@0:         WeakMapBase::removeWeakMapFromList(map);
michael@0:     map->check();
michael@0:     js_delete(map);
michael@0:     ptr = nullptr;
michael@0: }
michael@0: 
michael@0: template <typename K, typename V>
michael@0: bool
michael@0: JS::WeakMapPtr<K, V>::init(JSContext *cx)
michael@0: {
michael@0:     MOZ_ASSERT(!initialized());
michael@0:     typename Utils<K, V>::PtrType map = cx->runtime()->new_<typename Utils<K,V>::Type>(cx);
michael@0:     if (!map || !map->init())
michael@0:         return false;
michael@0:     ptr = map;
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: template <typename K, typename V>
michael@0: void
michael@0: JS::WeakMapPtr<K, V>::trace(JSTracer *trc)
michael@0: {
michael@0:     MOZ_ASSERT(initialized());
michael@0:     return Utils<K, V>::cast(ptr)->trace(trc);
michael@0: }
michael@0: 
michael@0: template <typename K, typename V>
michael@0: V
michael@0: JS::WeakMapPtr<K, V>::lookup(const K &key)
michael@0: {
michael@0:     MOZ_ASSERT(initialized());
michael@0:     typename Utils<K, V>::Type::Ptr result = Utils<K, V>::cast(ptr)->lookup(key);
michael@0:     if (!result)
michael@0:         return DataType<V>::NullValue();
michael@0:     return result->value();
michael@0: }
michael@0: 
michael@0: template <typename K, typename V>
michael@0: /* static */ void
michael@0: JS::WeakMapPtr<K, V>::keyMarkCallback(JSTracer *trc, K key, void *data)
michael@0: {
michael@0:     auto map = static_cast< JS::WeakMapPtr<K, V>* >(data);
michael@0:     K prior = key;
michael@0:     JS_CallObjectTracer(trc, &key, "WeakMapPtr key");
michael@0:     return Utils<K, V>::cast(map->ptr)->rekeyIfMoved(prior, key);
michael@0: }
michael@0: 
michael@0: template <typename K, typename V>
michael@0: bool
michael@0: JS::WeakMapPtr<K, V>::put(JSContext *cx, const K &key, const V &value)
michael@0: {
michael@0:     MOZ_ASSERT(initialized());
michael@0:     if (!Utils<K, V>::cast(ptr)->put(key, value))
michael@0:         return false;
michael@0:     JS_StoreObjectPostBarrierCallback(cx, keyMarkCallback, key, this);
michael@0:     // Values do not need to be barriered because only put() is supported,
michael@0:     // which is always an initializing write.
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: //
michael@0: // Supported specializations of JS::WeakMap:
michael@0: //
michael@0: 
michael@0: template class JS::WeakMapPtr<JSObject*, JSObject*>;
michael@0: 
michael@0: #ifdef DEBUG
michael@0: // Nobody's using this at the moment, but we want to make sure it compiles.
michael@0: template class JS::WeakMapPtr<JSObject*, JS::Value>;
michael@0: #endif