michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
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 file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef mozilla_dom_DOMJSProxyHandler_h
michael@0: #define mozilla_dom_DOMJSProxyHandler_h
michael@0: 
michael@0: #include "mozilla/Attributes.h"
michael@0: #include "mozilla/Likely.h"
michael@0: 
michael@0: #include "jsapi.h"
michael@0: #include "jsproxy.h"
michael@0: #include "nsString.h"
michael@0: 
michael@0: #define DOM_PROXY_OBJECT_SLOT js::PROXY_PRIVATE_SLOT
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: 
michael@0: class DOMClass;
michael@0: 
michael@0: enum {
michael@0:   JSPROXYSLOT_EXPANDO = 0
michael@0: };
michael@0: 
michael@0: template<typename T> struct Prefable;
michael@0: 
michael@0: // This variable exists solely to provide a unique address for use as an identifier.
michael@0: extern const char HandlerFamily;
michael@0: inline const void* ProxyFamily() { return &HandlerFamily; }
michael@0: 
michael@0: inline bool IsDOMProxy(JSObject *obj)
michael@0: {
michael@0:     const js::Class* clasp = js::GetObjectClass(obj);
michael@0:     return clasp->isProxy() &&
michael@0:            js::GetProxyHandler(obj)->family() == ProxyFamily();
michael@0: }
michael@0: 
michael@0: class BaseDOMProxyHandler : public js::BaseProxyHandler
michael@0: {
michael@0: public:
michael@0:   BaseDOMProxyHandler(const void* aProxyFamily)
michael@0:     : js::BaseProxyHandler(aProxyFamily)
michael@0:   {}
michael@0: 
michael@0:   // Implementations of traps that can be implemented in terms of
michael@0:   // fundamental traps.
michael@0:   bool enumerate(JSContext* cx, JS::Handle<JSObject*> proxy,
michael@0:                  JS::AutoIdVector& props) MOZ_OVERRIDE;
michael@0:   bool getPropertyDescriptor(JSContext* cx, JS::Handle<JSObject*> proxy,
michael@0:                              JS::Handle<jsid> id,
michael@0:                              JS::MutableHandle<JSPropertyDescriptor> desc) MOZ_OVERRIDE;
michael@0:   bool getOwnPropertyDescriptor(JSContext* cx, JS::Handle<JSObject*> proxy,
michael@0:                                 JS::Handle<jsid> id,
michael@0:                                 JS::MutableHandle<JSPropertyDescriptor> desc) MOZ_OVERRIDE;
michael@0: 
michael@0:   bool watch(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
michael@0:              JS::Handle<JSObject*> callable) MOZ_OVERRIDE;
michael@0:   bool unwatch(JSContext* cx, JS::Handle<JSObject*> proxy,
michael@0:                JS::Handle<jsid> id) MOZ_OVERRIDE;
michael@0:   virtual bool getOwnPropertyNames(JSContext* cx, JS::Handle<JSObject*> proxy,
michael@0:                                    JS::AutoIdVector &props) MOZ_OVERRIDE;
michael@0:   // We override keys() and implement it directly instead of using the
michael@0:   // default implementation, which would getOwnPropertyNames and then
michael@0:   // filter out the non-enumerable ones.  This avoids doing
michael@0:   // unnecessary work during enumeration.
michael@0:   virtual bool keys(JSContext* cx, JS::Handle<JSObject*> proxy,
michael@0:                     JS::AutoIdVector &props) MOZ_OVERRIDE;
michael@0: 
michael@0: protected:
michael@0:   // Hook for subclasses to implement shared getOwnPropertyNames()/keys()
michael@0:   // functionality.  The "flags" argument is either JSITER_OWNONLY (for keys())
michael@0:   // or JSITER_OWNONLY | JSITER_HIDDEN (for getOwnPropertyNames()).
michael@0:   virtual bool ownPropNames(JSContext* cx, JS::Handle<JSObject*> proxy,
michael@0:                             unsigned flags,
michael@0:                             JS::AutoIdVector& props) = 0;
michael@0: 
michael@0:   // Hook for subclasses to allow set() to ignore named props while other things
michael@0:   // that look at property descriptors see them.  This is intentionally not
michael@0:   // named getOwnPropertyDescriptor to avoid subclasses that override it hiding
michael@0:   // our public getOwnPropertyDescriptor.
michael@0:   virtual bool getOwnPropDescriptor(JSContext* cx,
michael@0:                                     JS::Handle<JSObject*> proxy,
michael@0:                                     JS::Handle<jsid> id,
michael@0:                                     bool ignoreNamedProps,
michael@0:                                     JS::MutableHandle<JSPropertyDescriptor> desc) = 0;
michael@0: };
michael@0: 
michael@0: class DOMProxyHandler : public BaseDOMProxyHandler
michael@0: {
michael@0: public:
michael@0:   DOMProxyHandler()
michael@0:     : BaseDOMProxyHandler(ProxyFamily())
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   bool preventExtensions(JSContext *cx, JS::Handle<JSObject*> proxy) MOZ_OVERRIDE;
michael@0:   bool defineProperty(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
michael@0:                       JS::MutableHandle<JSPropertyDescriptor> desc) MOZ_OVERRIDE
michael@0:   {
michael@0:     bool unused;
michael@0:     return defineProperty(cx, proxy, id, desc, &unused);
michael@0:   }
michael@0:   virtual bool defineProperty(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
michael@0:                               JS::MutableHandle<JSPropertyDescriptor> desc, bool* defined);
michael@0:   bool set(JSContext *cx, JS::Handle<JSObject*> proxy, JS::Handle<JSObject*> receiver,
michael@0:            JS::Handle<jsid> id, bool strict, JS::MutableHandle<JS::Value> vp) MOZ_OVERRIDE;
michael@0:   bool delete_(JSContext* cx, JS::Handle<JSObject*> proxy,
michael@0:                JS::Handle<jsid> id, bool* bp) MOZ_OVERRIDE;
michael@0:   bool has(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id, bool* bp) MOZ_OVERRIDE;
michael@0:   bool isExtensible(JSContext *cx, JS::Handle<JSObject*> proxy, bool *extensible) MOZ_OVERRIDE;
michael@0: 
michael@0:   /*
michael@0:    * If assigning to proxy[id] hits a named setter with OverrideBuiltins or
michael@0:    * an indexed setter, call it and set *done to true on success. Otherwise, set
michael@0:    * *done to false.
michael@0:    */
michael@0:   virtual bool setCustom(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
michael@0:                          JS::MutableHandle<JS::Value> vp, bool *done);
michael@0: 
michael@0:   static JSObject* GetExpandoObject(JSObject* obj)
michael@0:   {
michael@0:     MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
michael@0:     JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
michael@0:     if (v.isObject()) {
michael@0:       return &v.toObject();
michael@0:     }
michael@0: 
michael@0:     if (v.isUndefined()) {
michael@0:       return nullptr;
michael@0:     }
michael@0: 
michael@0:     js::ExpandoAndGeneration* expandoAndGeneration =
michael@0:       static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
michael@0:     v = expandoAndGeneration->expando;
michael@0:     return v.isUndefined() ? nullptr : &v.toObject();
michael@0:   }
michael@0:   /* GetAndClearExpandoObject does not DROP or clear the preserving wrapper flag. */
michael@0:   static JSObject* GetAndClearExpandoObject(JSObject* obj);
michael@0:   static JSObject* EnsureExpandoObject(JSContext* cx,
michael@0:                                        JS::Handle<JSObject*> obj);
michael@0: };
michael@0: 
michael@0: inline DOMProxyHandler*
michael@0: GetDOMProxyHandler(JSObject* obj)
michael@0: {
michael@0:   MOZ_ASSERT(IsDOMProxy(obj));
michael@0:   return static_cast<DOMProxyHandler*>(js::GetProxyHandler(obj));
michael@0: }
michael@0: 
michael@0: extern jsid s_length_id;
michael@0: 
michael@0: int32_t IdToInt32(JSContext* cx, JS::Handle<jsid> id);
michael@0: 
michael@0: // XXXbz this should really return uint32_t, with the maximum value
michael@0: // meaning "not an index"...
michael@0: inline int32_t
michael@0: GetArrayIndexFromId(JSContext* cx, JS::Handle<jsid> id)
michael@0: {
michael@0:   if (MOZ_LIKELY(JSID_IS_INT(id))) {
michael@0:     return JSID_TO_INT(id);
michael@0:   }
michael@0:   if (MOZ_LIKELY(id == s_length_id)) {
michael@0:     return -1;
michael@0:   }
michael@0:   if (MOZ_LIKELY(JSID_IS_ATOM(id))) {
michael@0:     JSAtom* atom = JSID_TO_ATOM(id);
michael@0:     jschar s = *js::GetAtomChars(atom);
michael@0:     if (MOZ_LIKELY((unsigned)s >= 'a' && (unsigned)s <= 'z'))
michael@0:       return -1;
michael@0: 
michael@0:     uint32_t i;
michael@0:     JSLinearString* str = js::AtomToLinearString(JSID_TO_ATOM(id));
michael@0:     return js::StringIsArrayIndex(str, &i) ? i : -1;
michael@0:   }
michael@0:   return IdToInt32(cx, id);
michael@0: }
michael@0: 
michael@0: inline bool
michael@0: IsArrayIndex(int32_t index)
michael@0: {
michael@0:   return index >= 0;
michael@0: }
michael@0: 
michael@0: inline void
michael@0: FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc,
michael@0:                        JSObject* obj, bool readonly, bool enumerable = true)
michael@0: {
michael@0:   desc.object().set(obj);
michael@0:   desc.setAttributes((readonly ? JSPROP_READONLY : 0) |
michael@0:                      (enumerable ? JSPROP_ENUMERATE : 0));
michael@0:   desc.setGetter(nullptr);
michael@0:   desc.setSetter(nullptr);
michael@0: }
michael@0: 
michael@0: inline void
michael@0: FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc,
michael@0:                        JSObject* obj, JS::Value v,
michael@0:                        bool readonly, bool enumerable = true)
michael@0: {
michael@0:   desc.value().set(v);
michael@0:   FillPropertyDescriptor(desc, obj, readonly, enumerable);
michael@0: }
michael@0: 
michael@0: inline void
michael@0: FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc,
michael@0:                        JSObject* obj, unsigned attributes, JS::Value v)
michael@0: {
michael@0:   desc.object().set(obj);
michael@0:   desc.value().set(v);
michael@0:   desc.setAttributes(attributes);
michael@0:   desc.setGetter(nullptr);
michael@0:   desc.setSetter(nullptr);
michael@0: }
michael@0: 
michael@0: } // namespace dom
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif /* mozilla_dom_DOMProxyHandler_h */