Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "js/WeakMapPtr.h"
#include "gc/WeakMap-inl.h"
//
// Machinery for the externally-linkable JS::WeakMapPtr, which wraps js::WeakMap
// for a few public data types.
//
using namespace js;
namespace WeakMapDetails {
template <typename T>
struct DataType {};
template <>
struct DataType<JSObject*> {
using BarrieredType = HeapPtr<JSObject*>;
using HasherType = StableCellHasher<BarrieredType>;
static JSObject* NullValue() { return nullptr; }
};
template <>
struct DataType<JS::Value> {
using BarrieredType = HeapPtr<Value>;
static JS::Value NullValue() { return JS::UndefinedValue(); }
};
template <typename K, typename V>
struct Utils {
using KeyType = typename DataType<K>::BarrieredType;
using ValueType = typename DataType<V>::BarrieredType;
using Type = WeakMap<KeyType, ValueType>;
using PtrType = Type*;
static PtrType cast(void* ptr) { return static_cast<PtrType>(ptr); }
};
} // namespace WeakMapDetails
template <typename K, typename V>
void JS::WeakMapPtr<K, V>::destroy() {
MOZ_ASSERT(initialized());
js_delete(WeakMapDetails::Utils<K, V>::cast(ptr));
ptr = nullptr;
}
template <typename K, typename V>
bool JS::WeakMapPtr<K, V>::init(JSContext* cx) {
MOZ_ASSERT(!initialized());
typename WeakMapDetails::Utils<K, V>::PtrType map =
cx->new_<typename WeakMapDetails::Utils<K, V>::Type>(cx);
if (!map) {
return false;
}
ptr = map;
return true;
}
template <typename K, typename V>
void JS::WeakMapPtr<K, V>::trace(JSTracer* trc) {
MOZ_ASSERT(initialized());
return WeakMapDetails::Utils<K, V>::cast(ptr)->trace(trc);
}
template <typename K, typename V>
V JS::WeakMapPtr<K, V>::lookup(const K& key) {
MOZ_ASSERT(initialized());
typename WeakMapDetails::Utils<K, V>::Type::Ptr result =
WeakMapDetails::Utils<K, V>::cast(ptr)->lookup(key);
if (!result) {
return WeakMapDetails::DataType<V>::NullValue();
}
return result->value();
}
template <typename K, typename V>
bool JS::WeakMapPtr<K, V>::put(JSContext* cx, const K& key, const V& value) {
MOZ_ASSERT(initialized());
return WeakMapDetails::Utils<K, V>::cast(ptr)->put(key, value);
}
template <typename K, typename V>
V JS::WeakMapPtr<K, V>::removeValue(const K& key) {
using Map = typename WeakMapDetails::Utils<K, V>::Type;
using Ptr = typename Map::Ptr;
MOZ_ASSERT(initialized());
Map* map = WeakMapDetails::Utils<K, V>::cast(ptr);
if (Ptr result = map->lookup(key)) {
V value = result->value();
map->remove(result);
return value;
}
return WeakMapDetails::DataType<V>::NullValue();
}
//
// Supported specializations of JS::WeakMap:
//
template class JS_PUBLIC_API JS::WeakMapPtr<JSObject*, JSObject*>;
#ifdef DEBUG
// Nobody's using this at the moment, but we want to make sure it compiles.
template class JS_PUBLIC_API JS::WeakMapPtr<JSObject*, JS::Value>;
#endif