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 "jsweakmap.h"
michael@0: 
michael@0: #include <string.h>
michael@0: 
michael@0: #include "jsapi.h"
michael@0: #include "jscntxt.h"
michael@0: #include "jsfriendapi.h"
michael@0: #include "jsobj.h"
michael@0: #include "jswrapper.h"
michael@0: 
michael@0: #include "vm/GlobalObject.h"
michael@0: #include "vm/WeakMapObject.h"
michael@0: 
michael@0: #include "jsobjinlines.h"
michael@0: 
michael@0: using namespace js;
michael@0: 
michael@0: WeakMapBase::WeakMapBase(JSObject *memOf, JSCompartment *c)
michael@0:   : memberOf(memOf),
michael@0:     compartment(c),
michael@0:     next(WeakMapNotInList)
michael@0: {
michael@0:     JS_ASSERT_IF(memberOf, memberOf->compartment() == c);
michael@0: }
michael@0: 
michael@0: WeakMapBase::~WeakMapBase()
michael@0: {
michael@0:     JS_ASSERT(next == WeakMapNotInList);
michael@0: }
michael@0: 
michael@0: bool
michael@0: WeakMapBase::markCompartmentIteratively(JSCompartment *c, JSTracer *tracer)
michael@0: {
michael@0:     bool markedAny = false;
michael@0:     for (WeakMapBase *m = c->gcWeakMapList; m; m = m->next) {
michael@0:         if (m->markIteratively(tracer))
michael@0:             markedAny = true;
michael@0:     }
michael@0:     return markedAny;
michael@0: }
michael@0: 
michael@0: void
michael@0: WeakMapBase::sweepCompartment(JSCompartment *c)
michael@0: {
michael@0:     for (WeakMapBase *m = c->gcWeakMapList; m; m = m->next)
michael@0:         m->sweep();
michael@0: }
michael@0: 
michael@0: void
michael@0: WeakMapBase::traceAllMappings(WeakMapTracer *tracer)
michael@0: {
michael@0:     JSRuntime *rt = tracer->runtime;
michael@0:     for (CompartmentsIter c(rt, SkipAtoms); !c.done(); c.next()) {
michael@0:         for (WeakMapBase *m = c->gcWeakMapList; m; m = m->next)
michael@0:             m->traceMappings(tracer);
michael@0:     }
michael@0: }
michael@0: 
michael@0: void
michael@0: WeakMapBase::resetCompartmentWeakMapList(JSCompartment *c)
michael@0: {
michael@0:     JS_ASSERT(WeakMapNotInList != nullptr);
michael@0: 
michael@0:     WeakMapBase *m = c->gcWeakMapList;
michael@0:     c->gcWeakMapList = nullptr;
michael@0:     while (m) {
michael@0:         WeakMapBase *n = m->next;
michael@0:         m->next = WeakMapNotInList;
michael@0:         m = n;
michael@0:     }
michael@0: }
michael@0: 
michael@0: bool
michael@0: WeakMapBase::saveCompartmentWeakMapList(JSCompartment *c, WeakMapVector &vector)
michael@0: {
michael@0:     WeakMapBase *m = c->gcWeakMapList;
michael@0:     while (m) {
michael@0:         if (!vector.append(m))
michael@0:             return false;
michael@0:         m = m->next;
michael@0:     }
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: void
michael@0: WeakMapBase::restoreCompartmentWeakMapLists(WeakMapVector &vector)
michael@0: {
michael@0:     for (WeakMapBase **p = vector.begin(); p != vector.end(); p++) {
michael@0:         WeakMapBase *m = *p;
michael@0:         JS_ASSERT(m->next == WeakMapNotInList);
michael@0:         JSCompartment *c = m->compartment;
michael@0:         m->next = c->gcWeakMapList;
michael@0:         c->gcWeakMapList = m;
michael@0:     }
michael@0: }
michael@0: 
michael@0: void
michael@0: WeakMapBase::removeWeakMapFromList(WeakMapBase *weakmap)
michael@0: {
michael@0:     JSCompartment *c = weakmap->compartment;
michael@0:     for (WeakMapBase **p = &c->gcWeakMapList; *p; p = &(*p)->next) {
michael@0:         if (*p == weakmap) {
michael@0:             *p = (*p)->next;
michael@0:             weakmap->next = WeakMapNotInList;
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: static JSObject *
michael@0: GetKeyArg(JSContext *cx, CallArgs &args)
michael@0: {
michael@0:     if (args[0].isPrimitive()) {
michael@0:         JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_NOT_NONNULL_OBJECT);
michael@0:         return nullptr;
michael@0:     }
michael@0:     return &args[0].toObject();
michael@0: }
michael@0: 
michael@0: MOZ_ALWAYS_INLINE bool
michael@0: IsWeakMap(HandleValue v)
michael@0: {
michael@0:     return v.isObject() && v.toObject().is<WeakMapObject>();
michael@0: }
michael@0: 
michael@0: MOZ_ALWAYS_INLINE bool
michael@0: WeakMap_has_impl(JSContext *cx, CallArgs args)
michael@0: {
michael@0:     JS_ASSERT(IsWeakMap(args.thisv()));
michael@0: 
michael@0:     if (args.length() < 1) {
michael@0:         JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED,
michael@0:                              "WeakMap.has", "0", "s");
michael@0:         return false;
michael@0:     }
michael@0:     JSObject *key = GetKeyArg(cx, args);
michael@0:     if (!key)
michael@0:         return false;
michael@0: 
michael@0:     if (ObjectValueMap *map = args.thisv().toObject().as<WeakMapObject>().getMap()) {
michael@0:         if (map->has(key)) {
michael@0:             args.rval().setBoolean(true);
michael@0:             return true;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     args.rval().setBoolean(false);
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: static bool
michael@0: WeakMap_has(JSContext *cx, unsigned argc, Value *vp)
michael@0: {
michael@0:     CallArgs args = CallArgsFromVp(argc, vp);
michael@0:     return CallNonGenericMethod<IsWeakMap, WeakMap_has_impl>(cx, args);
michael@0: }
michael@0: 
michael@0: MOZ_ALWAYS_INLINE bool
michael@0: WeakMap_clear_impl(JSContext *cx, CallArgs args)
michael@0: {
michael@0:     JS_ASSERT(IsWeakMap(args.thisv()));
michael@0: 
michael@0:     // We can't js_delete the weakmap because the data gathered during GC
michael@0:     // is used by the Cycle Collector
michael@0:     if (ObjectValueMap *map = args.thisv().toObject().as<WeakMapObject>().getMap())
michael@0:         map->clear();
michael@0: 
michael@0:     args.rval().setUndefined();
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: static bool
michael@0: WeakMap_clear(JSContext *cx, unsigned argc, Value *vp)
michael@0: {
michael@0:     CallArgs args = CallArgsFromVp(argc, vp);
michael@0:     return CallNonGenericMethod<IsWeakMap, WeakMap_clear_impl>(cx, args);
michael@0: }
michael@0: 
michael@0: MOZ_ALWAYS_INLINE bool
michael@0: WeakMap_get_impl(JSContext *cx, CallArgs args)
michael@0: {
michael@0:     JS_ASSERT(IsWeakMap(args.thisv()));
michael@0: 
michael@0:     if (args.length() < 1) {
michael@0:         JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED,
michael@0:                              "WeakMap.get", "0", "s");
michael@0:         return false;
michael@0:     }
michael@0:     JSObject *key = GetKeyArg(cx, args);
michael@0:     if (!key)
michael@0:         return false;
michael@0: 
michael@0:     if (ObjectValueMap *map = args.thisv().toObject().as<WeakMapObject>().getMap()) {
michael@0:         if (ObjectValueMap::Ptr ptr = map->lookup(key)) {
michael@0:             // Read barrier to prevent an incorrectly gray value from escaping the
michael@0:             // weak map. See the comment before UnmarkGrayChildren in gc/Marking.cpp
michael@0:             ExposeValueToActiveJS(ptr->value().get());
michael@0: 
michael@0:             args.rval().set(ptr->value());
michael@0:             return true;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     args.rval().set((args.length() > 1) ? args[1] : UndefinedValue());
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: static bool
michael@0: WeakMap_get(JSContext *cx, unsigned argc, Value *vp)
michael@0: {
michael@0:     CallArgs args = CallArgsFromVp(argc, vp);
michael@0:     return CallNonGenericMethod<IsWeakMap, WeakMap_get_impl>(cx, args);
michael@0: }
michael@0: 
michael@0: MOZ_ALWAYS_INLINE bool
michael@0: WeakMap_delete_impl(JSContext *cx, CallArgs args)
michael@0: {
michael@0:     JS_ASSERT(IsWeakMap(args.thisv()));
michael@0: 
michael@0:     if (args.length() < 1) {
michael@0:         JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED,
michael@0:                              "WeakMap.delete", "0", "s");
michael@0:         return false;
michael@0:     }
michael@0:     JSObject *key = GetKeyArg(cx, args);
michael@0:     if (!key)
michael@0:         return false;
michael@0: 
michael@0:     if (ObjectValueMap *map = args.thisv().toObject().as<WeakMapObject>().getMap()) {
michael@0:         if (ObjectValueMap::Ptr ptr = map->lookup(key)) {
michael@0:             map->remove(ptr);
michael@0:             args.rval().setBoolean(true);
michael@0:             return true;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     args.rval().setBoolean(false);
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: static bool
michael@0: WeakMap_delete(JSContext *cx, unsigned argc, Value *vp)
michael@0: {
michael@0:     CallArgs args = CallArgsFromVp(argc, vp);
michael@0:     return CallNonGenericMethod<IsWeakMap, WeakMap_delete_impl>(cx, args);
michael@0: }
michael@0: 
michael@0: static bool
michael@0: TryPreserveReflector(JSContext *cx, HandleObject obj)
michael@0: {
michael@0:     if (obj->getClass()->ext.isWrappedNative ||
michael@0:         (obj->getClass()->flags & JSCLASS_IS_DOMJSCLASS) ||
michael@0:         (obj->is<ProxyObject>() &&
michael@0:          obj->as<ProxyObject>().handler()->family() == GetDOMProxyHandlerFamily()))
michael@0:     {
michael@0:         JS_ASSERT(cx->runtime()->preserveWrapperCallback);
michael@0:         if (!cx->runtime()->preserveWrapperCallback(cx, obj)) {
michael@0:             JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_BAD_WEAKMAP_KEY);
michael@0:             return false;
michael@0:         }
michael@0:     }
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: static inline void
michael@0: WeakMapPostWriteBarrier(JSRuntime *rt, ObjectValueMap *weakMap, JSObject *key)
michael@0: {
michael@0: #ifdef JSGC_GENERATIONAL
michael@0:     /*
michael@0:      * Strip the barriers from the type before inserting into the store buffer.
michael@0:      * This will automatically ensure that barriers do not fire during GC.
michael@0:      *
michael@0:      * Some compilers complain about instantiating the WeakMap class for
michael@0:      * unbarriered type arguments, so we cast to a HashMap instead.  Because of
michael@0:      * WeakMap's multiple inheritace, We need to do this in two stages, first to
michael@0:      * the HashMap base class and then to the unbarriered version.
michael@0:      */
michael@0:     ObjectValueMap::Base *baseHashMap = static_cast<ObjectValueMap::Base *>(weakMap);
michael@0: 
michael@0:     typedef HashMap<JSObject *, Value> UnbarrieredMap;
michael@0:     UnbarrieredMap *unbarrieredMap = reinterpret_cast<UnbarrieredMap *>(baseHashMap);
michael@0: 
michael@0:     typedef gc::HashKeyRef<UnbarrieredMap, JSObject *> Ref;
michael@0:     if (key && IsInsideNursery(rt, key))
michael@0:         rt->gcStoreBuffer.putGeneric(Ref((unbarrieredMap), key));
michael@0: #endif
michael@0: }
michael@0: 
michael@0: MOZ_ALWAYS_INLINE bool
michael@0: SetWeakMapEntryInternal(JSContext *cx, Handle<WeakMapObject*> mapObj,
michael@0:                         HandleObject key, HandleValue value)
michael@0: {
michael@0:     ObjectValueMap *map = mapObj->getMap();
michael@0:     if (!map) {
michael@0:         map = cx->new_<ObjectValueMap>(cx, mapObj.get());
michael@0:         if (!map)
michael@0:             return false;
michael@0:         if (!map->init()) {
michael@0:             js_delete(map);
michael@0:             JS_ReportOutOfMemory(cx);
michael@0:             return false;
michael@0:         }
michael@0:         mapObj->setPrivate(map);
michael@0:     }
michael@0: 
michael@0:     // Preserve wrapped native keys to prevent wrapper optimization.
michael@0:     if (!TryPreserveReflector(cx, key))
michael@0:         return false;
michael@0: 
michael@0:     if (JSWeakmapKeyDelegateOp op = key->getClass()->ext.weakmapKeyDelegateOp) {
michael@0:         RootedObject delegate(cx, op(key));
michael@0:         if (delegate && !TryPreserveReflector(cx, delegate))
michael@0:             return false;
michael@0:     }
michael@0: 
michael@0:     JS_ASSERT(key->compartment() == mapObj->compartment());
michael@0:     JS_ASSERT_IF(value.isObject(), value.toObject().compartment() == mapObj->compartment());
michael@0:     if (!map->put(key, value)) {
michael@0:         JS_ReportOutOfMemory(cx);
michael@0:         return false;
michael@0:     }
michael@0:     WeakMapPostWriteBarrier(cx->runtime(), map, key.get());
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: MOZ_ALWAYS_INLINE bool
michael@0: WeakMap_set_impl(JSContext *cx, CallArgs args)
michael@0: {
michael@0:     JS_ASSERT(IsWeakMap(args.thisv()));
michael@0: 
michael@0:     if (args.length() < 1) {
michael@0:         JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED,
michael@0:                              "WeakMap.set", "0", "s");
michael@0:         return false;
michael@0:     }
michael@0:     RootedObject key(cx, GetKeyArg(cx, args));
michael@0:     if (!key)
michael@0:         return false;
michael@0: 
michael@0:     RootedValue value(cx, (args.length() > 1) ? args[1] : UndefinedValue());
michael@0:     Rooted<JSObject*> thisObj(cx, &args.thisv().toObject());
michael@0:     Rooted<WeakMapObject*> map(cx, &thisObj->as<WeakMapObject>());
michael@0: 
michael@0:     args.rval().setUndefined();
michael@0:     return SetWeakMapEntryInternal(cx, map, key, value);
michael@0: }
michael@0: 
michael@0: static bool
michael@0: WeakMap_set(JSContext *cx, unsigned argc, Value *vp)
michael@0: {
michael@0:     CallArgs args = CallArgsFromVp(argc, vp);
michael@0:     return CallNonGenericMethod<IsWeakMap, WeakMap_set_impl>(cx, args);
michael@0: }
michael@0: 
michael@0: JS_FRIEND_API(bool)
michael@0: JS_NondeterministicGetWeakMapKeys(JSContext *cx, HandleObject objArg, MutableHandleObject ret)
michael@0: {
michael@0:     RootedObject obj(cx, objArg);
michael@0:     obj = UncheckedUnwrap(obj);
michael@0:     if (!obj || !obj->is<WeakMapObject>()) {
michael@0:         ret.set(nullptr);
michael@0:         return true;
michael@0:     }
michael@0:     RootedObject arr(cx, NewDenseEmptyArray(cx));
michael@0:     if (!arr)
michael@0:         return false;
michael@0:     ObjectValueMap *map = obj->as<WeakMapObject>().getMap();
michael@0:     if (map) {
michael@0:         // Prevent GC from mutating the weakmap while iterating.
michael@0:         gc::AutoSuppressGC suppress(cx);
michael@0:         for (ObjectValueMap::Base::Range r = map->all(); !r.empty(); r.popFront()) {
michael@0:             RootedObject key(cx, r.front().key());
michael@0:             if (!cx->compartment()->wrap(cx, &key))
michael@0:                 return false;
michael@0:             if (!NewbornArrayPush(cx, arr, ObjectValue(*key)))
michael@0:                 return false;
michael@0:         }
michael@0:     }
michael@0:     ret.set(arr);
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: static void
michael@0: WeakMap_mark(JSTracer *trc, JSObject *obj)
michael@0: {
michael@0:     if (ObjectValueMap *map = obj->as<WeakMapObject>().getMap())
michael@0:         map->trace(trc);
michael@0: }
michael@0: 
michael@0: static void
michael@0: WeakMap_finalize(FreeOp *fop, JSObject *obj)
michael@0: {
michael@0:     if (ObjectValueMap *map = obj->as<WeakMapObject>().getMap()) {
michael@0:         map->check();
michael@0: #ifdef DEBUG
michael@0:         map->~ObjectValueMap();
michael@0:         memset(static_cast<void *>(map), 0xdc, sizeof(*map));
michael@0:         fop->free_(map);
michael@0: #else
michael@0:         fop->delete_(map);
michael@0: #endif
michael@0:     }
michael@0: }
michael@0: 
michael@0: JS_PUBLIC_API(JSObject*)
michael@0: JS::NewWeakMapObject(JSContext *cx)
michael@0: {
michael@0:     return NewBuiltinClassInstance(cx, &WeakMapObject::class_);
michael@0: }
michael@0: 
michael@0: JS_PUBLIC_API(bool)
michael@0: JS::IsWeakMapObject(JSObject *obj)
michael@0: {
michael@0:     return obj->is<WeakMapObject>();
michael@0: }
michael@0: 
michael@0: JS_PUBLIC_API(bool)
michael@0: JS::GetWeakMapEntry(JSContext *cx, HandleObject mapObj, HandleObject key,
michael@0:                     MutableHandleValue rval)
michael@0: {
michael@0:     CHECK_REQUEST(cx);
michael@0:     assertSameCompartment(cx, key);
michael@0:     rval.setUndefined();
michael@0:     ObjectValueMap *map = mapObj->as<WeakMapObject>().getMap();
michael@0:     if (!map)
michael@0:         return true;
michael@0:     if (ObjectValueMap::Ptr ptr = map->lookup(key)) {
michael@0:         // Read barrier to prevent an incorrectly gray value from escaping the
michael@0:         // weak map. See the comment before UnmarkGrayChildren in gc/Marking.cpp
michael@0:         ExposeValueToActiveJS(ptr->value().get());
michael@0:         rval.set(ptr->value());
michael@0:     }
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: JS_PUBLIC_API(bool)
michael@0: JS::SetWeakMapEntry(JSContext *cx, HandleObject mapObj, HandleObject key,
michael@0:                     HandleValue val)
michael@0: {
michael@0:     CHECK_REQUEST(cx);
michael@0:     assertSameCompartment(cx, key, val);
michael@0:     Rooted<WeakMapObject*> rootedMap(cx, &mapObj->as<WeakMapObject>());
michael@0:     return SetWeakMapEntryInternal(cx, rootedMap, key, val);
michael@0: }
michael@0: 
michael@0: static bool
michael@0: WeakMap_construct(JSContext *cx, unsigned argc, Value *vp)
michael@0: {
michael@0:     CallArgs args = CallArgsFromVp(argc, vp);
michael@0:     JSObject *obj = NewBuiltinClassInstance(cx, &WeakMapObject::class_);
michael@0:     if (!obj)
michael@0:         return false;
michael@0: 
michael@0:     args.rval().setObject(*obj);
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: const Class WeakMapObject::class_ = {
michael@0:     "WeakMap",
michael@0:     JSCLASS_HAS_PRIVATE | JSCLASS_IMPLEMENTS_BARRIERS |
michael@0:     JSCLASS_HAS_CACHED_PROTO(JSProto_WeakMap),
michael@0:     JS_PropertyStub,         /* addProperty */
michael@0:     JS_DeletePropertyStub,   /* delProperty */
michael@0:     JS_PropertyStub,         /* getProperty */
michael@0:     JS_StrictPropertyStub,   /* setProperty */
michael@0:     JS_EnumerateStub,
michael@0:     JS_ResolveStub,
michael@0:     JS_ConvertStub,
michael@0:     WeakMap_finalize,
michael@0:     nullptr,                 /* call        */
michael@0:     nullptr,                 /* construct   */
michael@0:     nullptr,                 /* xdrObject   */
michael@0:     WeakMap_mark
michael@0: };
michael@0: 
michael@0: static const JSFunctionSpec weak_map_methods[] = {
michael@0:     JS_FN("has",    WeakMap_has, 1, 0),
michael@0:     JS_FN("get",    WeakMap_get, 2, 0),
michael@0:     JS_FN("delete", WeakMap_delete, 1, 0),
michael@0:     JS_FN("set",    WeakMap_set, 2, 0),
michael@0:     JS_FN("clear",  WeakMap_clear, 0, 0),
michael@0:     JS_FS_END
michael@0: };
michael@0: 
michael@0: JSObject *
michael@0: js_InitWeakMapClass(JSContext *cx, HandleObject obj)
michael@0: {
michael@0:     JS_ASSERT(obj->isNative());
michael@0: 
michael@0:     Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
michael@0: 
michael@0:     RootedObject weakMapProto(cx, global->createBlankPrototype(cx, &WeakMapObject::class_));
michael@0:     if (!weakMapProto)
michael@0:         return nullptr;
michael@0: 
michael@0:     RootedFunction ctor(cx, global->createConstructor(cx, WeakMap_construct,
michael@0:                                                       cx->names().WeakMap, 0));
michael@0:     if (!ctor)
michael@0:         return nullptr;
michael@0: 
michael@0:     if (!LinkConstructorAndPrototype(cx, ctor, weakMapProto))
michael@0:         return nullptr;
michael@0: 
michael@0:     if (!DefinePropertiesAndBrand(cx, weakMapProto, nullptr, weak_map_methods))
michael@0:         return nullptr;
michael@0: 
michael@0:     if (!GlobalObject::initBuiltinConstructor(cx, global, JSProto_WeakMap, ctor, weakMapProto))
michael@0:         return nullptr;
michael@0:     return weakMapProto;
michael@0: }
michael@0: