/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- * vim: set ts=4 sw=4 et tw=99: * * 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 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef jsproxy_h___ #define jsproxy_h___ #include "jsapi.h" #include "jsfriendapi.h" namespace js { class Wrapper; /* * A proxy is a JSObject that implements generic behavior by providing custom * implementations for each object trap. The implementation for each trap is * provided by a C++ object stored on the proxy, known as its handler. * * A major use case for proxies is to forward each trap to another object, * known as its target. The target can be an arbitrary C++ object. Not every * proxy has the notion of a target, however. * * Proxy traps are grouped into fundamental and derived traps. Every proxy has * to at least provide implementations for the fundamental traps, but the * derived traps can be implemented in terms of the fundamental ones. * * To minimize code duplication, a set of abstract proxy handler classes is * provided, from which other handlers may inherit. These abstract classes * are organized in the following hierarchy: * * BaseProxyHandler * | * IndirectProxyHandler * | * DirectProxyHandler */ /* * BaseProxyHandler is the most generic kind of proxy handler. It does not make * any assumptions about the target. Consequently, it does not provide any * default implementation for the fundamental traps. It does, however, implement * the derived traps in terms of the fundamental ones. This allows consumers of * this class to define any custom behavior they want. */ class JS_FRIEND_API(BaseProxyHandler) { void *mFamily; public: explicit BaseProxyHandler(void *family); virtual ~BaseProxyHandler(); inline void *family() { return mFamily; } virtual bool isOuterWindow() { return false; } /* * The function Wrapper::wrapperHandler takes a pointer to a * BaseProxyHandler and returns a pointer to a Wrapper if and only if the * BaseProxyHandler is a wrapper handler (otherwise, it returns NULL). * * Unfortunately, we can't inherit Wrapper from BaseProxyHandler, since that * would create a dreaded diamond, and we can't use dynamic_cast to cast * BaseProxyHandler to Wrapper, since that would require us to compile with * run-time type information. Hence the need for this virtual function. */ virtual Wrapper *toWrapper() { return NULL; } /* ES5 Harmony fundamental proxy traps. */ virtual bool getPropertyDescriptor(JSContext *cx, JSObject *proxy, jsid id, bool set, PropertyDescriptor *desc) = 0; virtual bool getOwnPropertyDescriptor(JSContext *cx, JSObject *proxy, jsid id, bool set, PropertyDescriptor *desc) = 0; virtual bool defineProperty(JSContext *cx, JSObject *proxy, jsid id, PropertyDescriptor *desc) = 0; virtual bool getOwnPropertyNames(JSContext *cx, JSObject *proxy, AutoIdVector &props) = 0; virtual bool delete_(JSContext *cx, JSObject *proxy, jsid id, bool *bp) = 0; virtual bool enumerate(JSContext *cx, JSObject *proxy, AutoIdVector &props) = 0; /* ES5 Harmony derived proxy traps. */ virtual bool has(JSContext *cx, JSObject *proxy, jsid id, bool *bp); virtual bool hasOwn(JSContext *cx, JSObject *proxy, jsid id, bool *bp); virtual bool get(JSContext *cx, JSObject *proxy, JSObject *receiver, jsid id, Value *vp); virtual bool set(JSContext *cx, JSObject *proxy, JSObject *receiver, jsid id, bool strict, Value *vp); virtual bool keys(JSContext *cx, JSObject *proxy, AutoIdVector &props); virtual bool iterate(JSContext *cx, JSObject *proxy, unsigned flags, Value *vp); /* Spidermonkey extensions. */ virtual bool call(JSContext *cx, JSObject *proxy, unsigned argc, Value *vp); virtual bool construct(JSContext *cx, JSObject *proxy, unsigned argc, Value *argv, Value *rval); virtual bool nativeCall(JSContext *cx, JSObject *proxy, Class *clasp, Native native, CallArgs args); virtual bool hasInstance(JSContext *cx, JSObject *proxy, const Value *vp, bool *bp); virtual JSType typeOf(JSContext *cx, JSObject *proxy); virtual bool objectClassIs(JSObject *obj, ESClassValue classValue, JSContext *cx); virtual JSString *obj_toString(JSContext *cx, JSObject *proxy); virtual JSString *fun_toString(JSContext *cx, JSObject *proxy, unsigned indent); virtual bool regexp_toShared(JSContext *cx, JSObject *proxy, RegExpGuard *g); virtual bool defaultValue(JSContext *cx, JSObject *obj, JSType hint, Value *vp); virtual bool iteratorNext(JSContext *cx, JSObject *proxy, Value *vp); virtual void finalize(JSFreeOp *fop, JSObject *proxy); virtual bool getElementIfPresent(JSContext *cx, JSObject *obj, JSObject *receiver, uint32_t index, Value *vp, bool *present); }; /* * IndirectProxyHandler assumes that a target exists. Moreover, it assumes the * target is a JSObject. Consequently, it provides default implementations for * the fundamental traps that forward their behavior to the target. The derived * traps, however, are inherited from BaseProxyHandler, and therefore still * implemented in terms of the fundamental ones. This allows consumers of this * class to define custom behavior without implementing the entire gamut of * proxy traps. */ class JS_PUBLIC_API(IndirectProxyHandler) : public BaseProxyHandler { public: explicit IndirectProxyHandler(void *family); /* ES5 Harmony fundamental proxy traps. */ virtual bool getPropertyDescriptor(JSContext *cx, JSObject *proxy, jsid id, bool set, PropertyDescriptor *desc) MOZ_OVERRIDE; virtual bool getOwnPropertyDescriptor(JSContext *cx, JSObject *proxy, jsid id, bool set, PropertyDescriptor *desc) MOZ_OVERRIDE; virtual bool defineProperty(JSContext *cx, JSObject *proxy, jsid id, PropertyDescriptor *desc) MOZ_OVERRIDE; virtual bool getOwnPropertyNames(JSContext *cx, JSObject *proxy, AutoIdVector &props) MOZ_OVERRIDE; virtual bool delete_(JSContext *cx, JSObject *proxy, jsid id, bool *bp) MOZ_OVERRIDE; virtual bool enumerate(JSContext *cx, JSObject *proxy, AutoIdVector &props) MOZ_OVERRIDE; /* Spidermonkey extensions. */ virtual bool call(JSContext *cx, JSObject *proxy, unsigned argc, Value *vp) MOZ_OVERRIDE; virtual bool construct(JSContext *cx, JSObject *proxy, unsigned argc, Value *argv, Value *rval) MOZ_OVERRIDE; virtual bool nativeCall(JSContext *cx, JSObject *proxy, Class *clasp, Native native, CallArgs args) MOZ_OVERRIDE; virtual bool hasInstance(JSContext *cx, JSObject *proxy, const Value *vp, bool *bp) MOZ_OVERRIDE; virtual JSType typeOf(JSContext *cx, JSObject *proxy) MOZ_OVERRIDE; virtual bool objectClassIs(JSObject *obj, ESClassValue classValue, JSContext *cx) MOZ_OVERRIDE; virtual JSString *obj_toString(JSContext *cx, JSObject *proxy) MOZ_OVERRIDE; virtual JSString *fun_toString(JSContext *cx, JSObject *proxy, unsigned indent) MOZ_OVERRIDE; virtual bool regexp_toShared(JSContext *cx, JSObject *proxy, RegExpGuard *g) MOZ_OVERRIDE; virtual bool defaultValue(JSContext *cx, JSObject *obj, JSType hint, Value *vp) MOZ_OVERRIDE; virtual bool iteratorNext(JSContext *cx, JSObject *proxy, Value *vp) MOZ_OVERRIDE; }; /* * DirectProxyHandler has the same assumptions about the target as its base, * IndirectProxyHandler. Its fundamental traps are inherited from this class, * and therefore forward their behavior to the target. The derived traps, * however, are overrided so that, they too, forward their behavior to the * target. This allows consumers of this class to forward to another object as * transparently as possible. */ class JS_PUBLIC_API(DirectProxyHandler) : public IndirectProxyHandler { public: explicit DirectProxyHandler(void *family); /* ES5 Harmony derived proxy traps. */ virtual bool has(JSContext *cx, JSObject *proxy, jsid id, bool *bp) MOZ_OVERRIDE; virtual bool hasOwn(JSContext *cx, JSObject *proxy, jsid id, bool *bp) MOZ_OVERRIDE; virtual bool get(JSContext *cx, JSObject *proxy, JSObject *receiver, jsid id, Value *vp) MOZ_OVERRIDE; virtual bool set(JSContext *cx, JSObject *proxy, JSObject *receiver, jsid id, bool strict, Value *vp) MOZ_OVERRIDE; virtual bool keys(JSContext *cx, JSObject *proxy, AutoIdVector &props) MOZ_OVERRIDE; virtual bool iterate(JSContext *cx, JSObject *proxy, unsigned flags, Value *vp) MOZ_OVERRIDE; }; /* Dispatch point for handlers that executes the appropriate C++ or scripted traps. */ class Proxy { public: /* ES5 Harmony fundamental proxy traps. */ static bool getPropertyDescriptor(JSContext *cx, JSObject *proxy, jsid id, bool set, PropertyDescriptor *desc); static bool getPropertyDescriptor(JSContext *cx, JSObject *proxy, jsid id, bool set, Value *vp); static bool getOwnPropertyDescriptor(JSContext *cx, JSObject *proxy, jsid id, bool set, PropertyDescriptor *desc); static bool getOwnPropertyDescriptor(JSContext *cx, JSObject *proxy, jsid id, bool set, Value *vp); static bool defineProperty(JSContext *cx, JSObject *proxy, jsid id, PropertyDescriptor *desc); static bool defineProperty(JSContext *cx, JSObject *proxy, jsid id, const Value &v); static bool getOwnPropertyNames(JSContext *cx, JSObject *proxy, AutoIdVector &props); static bool delete_(JSContext *cx, JSObject *proxy, jsid id, bool *bp); static bool enumerate(JSContext *cx, JSObject *proxy, AutoIdVector &props); /* ES5 Harmony derived proxy traps. */ static bool has(JSContext *cx, JSObject *proxy, jsid id, bool *bp); static bool hasOwn(JSContext *cx, JSObject *proxy, jsid id, bool *bp); static bool get(JSContext *cx, JSObject *proxy, JSObject *receiver, jsid id, Value *vp); static bool getElementIfPresent(JSContext *cx, JSObject *proxy, JSObject *receiver, uint32_t index, Value *vp, bool *present); static bool set(JSContext *cx, JSObject *proxy, JSObject *receiver, jsid id, bool strict, Value *vp); static bool keys(JSContext *cx, JSObject *proxy, AutoIdVector &props); static bool iterate(JSContext *cx, JSObject *proxy, unsigned flags, Value *vp); /* Spidermonkey extensions. */ static bool call(JSContext *cx, JSObject *proxy, unsigned argc, Value *vp); static bool construct(JSContext *cx, JSObject *proxy, unsigned argc, Value *argv, Value *rval); static bool nativeCall(JSContext *cx, JSObject *proxy, Class *clasp, Native native, CallArgs args); static bool hasInstance(JSContext *cx, JSObject *proxy, const Value *vp, bool *bp); static JSType typeOf(JSContext *cx, JSObject *proxy); static bool objectClassIs(JSObject *obj, ESClassValue classValue, JSContext *cx); static JSString *obj_toString(JSContext *cx, JSObject *proxy); static JSString *fun_toString(JSContext *cx, JSObject *proxy, unsigned indent); static bool regexp_toShared(JSContext *cx, JSObject *proxy, RegExpGuard *g); static bool defaultValue(JSContext *cx, JSObject *obj, JSType hint, Value *vp); static bool iteratorNext(JSContext *cx, JSObject *proxy, Value *vp); }; inline bool IsObjectProxyClass(const Class *clasp) { return clasp == &js::ObjectProxyClass || clasp == &js::OuterWindowProxyClass; } inline bool IsFunctionProxyClass(const Class *clasp) { return clasp == &js::FunctionProxyClass; } inline bool IsObjectProxy(const JSObject *obj) { return IsObjectProxyClass(GetObjectClass(obj)); } inline bool IsFunctionProxy(const JSObject *obj) { return IsFunctionProxyClass(GetObjectClass(obj)); } inline bool IsProxy(const JSObject *obj) { Class *clasp = GetObjectClass(obj); return IsObjectProxyClass(clasp) || IsFunctionProxyClass(clasp); } /* Shared between object and function proxies. */ const uint32_t JSSLOT_PROXY_HANDLER = 0; const uint32_t JSSLOT_PROXY_PRIVATE = 1; const uint32_t JSSLOT_PROXY_EXTRA = 2; /* Function proxies only. */ const uint32_t JSSLOT_PROXY_CALL = 4; const uint32_t JSSLOT_PROXY_CONSTRUCT = 5; inline BaseProxyHandler * GetProxyHandler(const JSObject *obj) { JS_ASSERT(IsProxy(obj)); return (BaseProxyHandler *) GetReservedSlot(obj, JSSLOT_PROXY_HANDLER).toPrivate(); } inline const Value & GetProxyPrivate(const JSObject *obj) { JS_ASSERT(IsProxy(obj)); return GetReservedSlot(obj, JSSLOT_PROXY_PRIVATE); } inline JSObject * GetProxyTargetObject(const JSObject *obj) { JS_ASSERT(IsProxy(obj)); return GetProxyPrivate(obj).toObjectOrNull(); } inline const Value & GetProxyCall(const JSObject *obj) { JS_ASSERT(IsFunctionProxy(obj)); return GetReservedSlot(obj, JSSLOT_PROXY_CALL); } inline const Value & GetProxyExtra(const JSObject *obj, size_t n) { JS_ASSERT(IsProxy(obj)); return GetReservedSlot(obj, JSSLOT_PROXY_EXTRA + n); } inline void SetProxyHandler(JSObject *obj, BaseProxyHandler *handler) { JS_ASSERT(IsProxy(obj)); SetReservedSlot(obj, JSSLOT_PROXY_HANDLER, PrivateValue(handler)); } inline void SetProxyPrivate(JSObject *obj, const Value &value) { JS_ASSERT(IsProxy(obj)); SetReservedSlot(obj, JSSLOT_PROXY_PRIVATE, value); } inline void SetProxyExtra(JSObject *obj, size_t n, const Value &extra) { JS_ASSERT(IsProxy(obj)); JS_ASSERT(n <= 1); SetReservedSlot(obj, JSSLOT_PROXY_EXTRA + n, extra); } JS_FRIEND_API(JSObject *) NewProxyObject(JSContext *cx, BaseProxyHandler *handler, const Value &priv, JSObject *proto, JSObject *parent, JSObject *call = NULL, JSObject *construct = NULL); } /* namespace js */ JS_BEGIN_EXTERN_C extern JS_FRIEND_API(JSObject *) js_InitProxyClass(JSContext *cx, JSObject *obj); JS_END_EXTERN_C #endif