1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/bindings/DOMJSProxyHandler.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,220 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.7 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef mozilla_dom_DOMJSProxyHandler_h
1.10 +#define mozilla_dom_DOMJSProxyHandler_h
1.11 +
1.12 +#include "mozilla/Attributes.h"
1.13 +#include "mozilla/Likely.h"
1.14 +
1.15 +#include "jsapi.h"
1.16 +#include "jsproxy.h"
1.17 +#include "nsString.h"
1.18 +
1.19 +#define DOM_PROXY_OBJECT_SLOT js::PROXY_PRIVATE_SLOT
1.20 +
1.21 +namespace mozilla {
1.22 +namespace dom {
1.23 +
1.24 +class DOMClass;
1.25 +
1.26 +enum {
1.27 + JSPROXYSLOT_EXPANDO = 0
1.28 +};
1.29 +
1.30 +template<typename T> struct Prefable;
1.31 +
1.32 +// This variable exists solely to provide a unique address for use as an identifier.
1.33 +extern const char HandlerFamily;
1.34 +inline const void* ProxyFamily() { return &HandlerFamily; }
1.35 +
1.36 +inline bool IsDOMProxy(JSObject *obj)
1.37 +{
1.38 + const js::Class* clasp = js::GetObjectClass(obj);
1.39 + return clasp->isProxy() &&
1.40 + js::GetProxyHandler(obj)->family() == ProxyFamily();
1.41 +}
1.42 +
1.43 +class BaseDOMProxyHandler : public js::BaseProxyHandler
1.44 +{
1.45 +public:
1.46 + BaseDOMProxyHandler(const void* aProxyFamily)
1.47 + : js::BaseProxyHandler(aProxyFamily)
1.48 + {}
1.49 +
1.50 + // Implementations of traps that can be implemented in terms of
1.51 + // fundamental traps.
1.52 + bool enumerate(JSContext* cx, JS::Handle<JSObject*> proxy,
1.53 + JS::AutoIdVector& props) MOZ_OVERRIDE;
1.54 + bool getPropertyDescriptor(JSContext* cx, JS::Handle<JSObject*> proxy,
1.55 + JS::Handle<jsid> id,
1.56 + JS::MutableHandle<JSPropertyDescriptor> desc) MOZ_OVERRIDE;
1.57 + bool getOwnPropertyDescriptor(JSContext* cx, JS::Handle<JSObject*> proxy,
1.58 + JS::Handle<jsid> id,
1.59 + JS::MutableHandle<JSPropertyDescriptor> desc) MOZ_OVERRIDE;
1.60 +
1.61 + bool watch(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
1.62 + JS::Handle<JSObject*> callable) MOZ_OVERRIDE;
1.63 + bool unwatch(JSContext* cx, JS::Handle<JSObject*> proxy,
1.64 + JS::Handle<jsid> id) MOZ_OVERRIDE;
1.65 + virtual bool getOwnPropertyNames(JSContext* cx, JS::Handle<JSObject*> proxy,
1.66 + JS::AutoIdVector &props) MOZ_OVERRIDE;
1.67 + // We override keys() and implement it directly instead of using the
1.68 + // default implementation, which would getOwnPropertyNames and then
1.69 + // filter out the non-enumerable ones. This avoids doing
1.70 + // unnecessary work during enumeration.
1.71 + virtual bool keys(JSContext* cx, JS::Handle<JSObject*> proxy,
1.72 + JS::AutoIdVector &props) MOZ_OVERRIDE;
1.73 +
1.74 +protected:
1.75 + // Hook for subclasses to implement shared getOwnPropertyNames()/keys()
1.76 + // functionality. The "flags" argument is either JSITER_OWNONLY (for keys())
1.77 + // or JSITER_OWNONLY | JSITER_HIDDEN (for getOwnPropertyNames()).
1.78 + virtual bool ownPropNames(JSContext* cx, JS::Handle<JSObject*> proxy,
1.79 + unsigned flags,
1.80 + JS::AutoIdVector& props) = 0;
1.81 +
1.82 + // Hook for subclasses to allow set() to ignore named props while other things
1.83 + // that look at property descriptors see them. This is intentionally not
1.84 + // named getOwnPropertyDescriptor to avoid subclasses that override it hiding
1.85 + // our public getOwnPropertyDescriptor.
1.86 + virtual bool getOwnPropDescriptor(JSContext* cx,
1.87 + JS::Handle<JSObject*> proxy,
1.88 + JS::Handle<jsid> id,
1.89 + bool ignoreNamedProps,
1.90 + JS::MutableHandle<JSPropertyDescriptor> desc) = 0;
1.91 +};
1.92 +
1.93 +class DOMProxyHandler : public BaseDOMProxyHandler
1.94 +{
1.95 +public:
1.96 + DOMProxyHandler()
1.97 + : BaseDOMProxyHandler(ProxyFamily())
1.98 + {
1.99 + }
1.100 +
1.101 + bool preventExtensions(JSContext *cx, JS::Handle<JSObject*> proxy) MOZ_OVERRIDE;
1.102 + bool defineProperty(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
1.103 + JS::MutableHandle<JSPropertyDescriptor> desc) MOZ_OVERRIDE
1.104 + {
1.105 + bool unused;
1.106 + return defineProperty(cx, proxy, id, desc, &unused);
1.107 + }
1.108 + virtual bool defineProperty(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
1.109 + JS::MutableHandle<JSPropertyDescriptor> desc, bool* defined);
1.110 + bool set(JSContext *cx, JS::Handle<JSObject*> proxy, JS::Handle<JSObject*> receiver,
1.111 + JS::Handle<jsid> id, bool strict, JS::MutableHandle<JS::Value> vp) MOZ_OVERRIDE;
1.112 + bool delete_(JSContext* cx, JS::Handle<JSObject*> proxy,
1.113 + JS::Handle<jsid> id, bool* bp) MOZ_OVERRIDE;
1.114 + bool has(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id, bool* bp) MOZ_OVERRIDE;
1.115 + bool isExtensible(JSContext *cx, JS::Handle<JSObject*> proxy, bool *extensible) MOZ_OVERRIDE;
1.116 +
1.117 + /*
1.118 + * If assigning to proxy[id] hits a named setter with OverrideBuiltins or
1.119 + * an indexed setter, call it and set *done to true on success. Otherwise, set
1.120 + * *done to false.
1.121 + */
1.122 + virtual bool setCustom(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
1.123 + JS::MutableHandle<JS::Value> vp, bool *done);
1.124 +
1.125 + static JSObject* GetExpandoObject(JSObject* obj)
1.126 + {
1.127 + MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
1.128 + JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
1.129 + if (v.isObject()) {
1.130 + return &v.toObject();
1.131 + }
1.132 +
1.133 + if (v.isUndefined()) {
1.134 + return nullptr;
1.135 + }
1.136 +
1.137 + js::ExpandoAndGeneration* expandoAndGeneration =
1.138 + static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
1.139 + v = expandoAndGeneration->expando;
1.140 + return v.isUndefined() ? nullptr : &v.toObject();
1.141 + }
1.142 + /* GetAndClearExpandoObject does not DROP or clear the preserving wrapper flag. */
1.143 + static JSObject* GetAndClearExpandoObject(JSObject* obj);
1.144 + static JSObject* EnsureExpandoObject(JSContext* cx,
1.145 + JS::Handle<JSObject*> obj);
1.146 +};
1.147 +
1.148 +inline DOMProxyHandler*
1.149 +GetDOMProxyHandler(JSObject* obj)
1.150 +{
1.151 + MOZ_ASSERT(IsDOMProxy(obj));
1.152 + return static_cast<DOMProxyHandler*>(js::GetProxyHandler(obj));
1.153 +}
1.154 +
1.155 +extern jsid s_length_id;
1.156 +
1.157 +int32_t IdToInt32(JSContext* cx, JS::Handle<jsid> id);
1.158 +
1.159 +// XXXbz this should really return uint32_t, with the maximum value
1.160 +// meaning "not an index"...
1.161 +inline int32_t
1.162 +GetArrayIndexFromId(JSContext* cx, JS::Handle<jsid> id)
1.163 +{
1.164 + if (MOZ_LIKELY(JSID_IS_INT(id))) {
1.165 + return JSID_TO_INT(id);
1.166 + }
1.167 + if (MOZ_LIKELY(id == s_length_id)) {
1.168 + return -1;
1.169 + }
1.170 + if (MOZ_LIKELY(JSID_IS_ATOM(id))) {
1.171 + JSAtom* atom = JSID_TO_ATOM(id);
1.172 + jschar s = *js::GetAtomChars(atom);
1.173 + if (MOZ_LIKELY((unsigned)s >= 'a' && (unsigned)s <= 'z'))
1.174 + return -1;
1.175 +
1.176 + uint32_t i;
1.177 + JSLinearString* str = js::AtomToLinearString(JSID_TO_ATOM(id));
1.178 + return js::StringIsArrayIndex(str, &i) ? i : -1;
1.179 + }
1.180 + return IdToInt32(cx, id);
1.181 +}
1.182 +
1.183 +inline bool
1.184 +IsArrayIndex(int32_t index)
1.185 +{
1.186 + return index >= 0;
1.187 +}
1.188 +
1.189 +inline void
1.190 +FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc,
1.191 + JSObject* obj, bool readonly, bool enumerable = true)
1.192 +{
1.193 + desc.object().set(obj);
1.194 + desc.setAttributes((readonly ? JSPROP_READONLY : 0) |
1.195 + (enumerable ? JSPROP_ENUMERATE : 0));
1.196 + desc.setGetter(nullptr);
1.197 + desc.setSetter(nullptr);
1.198 +}
1.199 +
1.200 +inline void
1.201 +FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc,
1.202 + JSObject* obj, JS::Value v,
1.203 + bool readonly, bool enumerable = true)
1.204 +{
1.205 + desc.value().set(v);
1.206 + FillPropertyDescriptor(desc, obj, readonly, enumerable);
1.207 +}
1.208 +
1.209 +inline void
1.210 +FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc,
1.211 + JSObject* obj, unsigned attributes, JS::Value v)
1.212 +{
1.213 + desc.object().set(obj);
1.214 + desc.value().set(v);
1.215 + desc.setAttributes(attributes);
1.216 + desc.setGetter(nullptr);
1.217 + desc.setSetter(nullptr);
1.218 +}
1.219 +
1.220 +} // namespace dom
1.221 +} // namespace mozilla
1.222 +
1.223 +#endif /* mozilla_dom_DOMProxyHandler_h */
