gecko-dev/dom/bindings/DOMJSProxyHandler.h

167 lines
5.0 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
/* 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 mozilla_dom_DOMJSProxyHandler_h
#define mozilla_dom_DOMJSProxyHandler_h
#include "mozilla/Attributes.h"
#include "mozilla/Likely.h"
#include "jsapi.h"
#include "jsproxy.h"
#include "nsString.h"
#define DOM_PROXY_OBJECT_SLOT js::PROXY_PRIVATE_SLOT
namespace mozilla {
namespace dom {
class DOMClass;
enum {
JSPROXYSLOT_EXPANDO = 0,
JSPROXYSLOT_XRAY_EXPANDO
};
template<typename T> struct Prefable;
// This variable exists solely to provide a unique address for use as an identifier.
extern const char HandlerFamily;
inline const void* ProxyFamily() { return &HandlerFamily; }
inline bool IsDOMProxy(JSObject *obj, const js::Class* clasp)
{
MOZ_ASSERT(js::GetObjectClass(obj) == clasp);
return (js::IsObjectProxyClass(clasp) || js::IsFunctionProxyClass(clasp)) &&
js::GetProxyHandler(obj)->family() == ProxyFamily();
}
inline bool IsDOMProxy(JSObject *obj)
{
return IsDOMProxy(obj, js::GetObjectClass(obj));
}
class BaseDOMProxyHandler : public js::BaseProxyHandler
{
public:
BaseDOMProxyHandler(const void* aProxyFamily)
: js::BaseProxyHandler(aProxyFamily)
{}
// Implementations of traps that can be implemented in terms of
// fundamental traps.
bool enumerate(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::AutoIdVector& props) MOZ_OVERRIDE;
bool getPropertyDescriptor(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::Handle<jsid> id,
JS::MutableHandle<JSPropertyDescriptor> desc,
unsigned flags) MOZ_OVERRIDE;
};
class DOMProxyHandler : public BaseDOMProxyHandler
{
public:
DOMProxyHandler(const DOMClass& aClass)
: BaseDOMProxyHandler(ProxyFamily()),
mClass(aClass)
{
}
bool preventExtensions(JSContext *cx, JS::Handle<JSObject*> proxy) MOZ_OVERRIDE;
bool defineProperty(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
JS::MutableHandle<JSPropertyDescriptor> desc) MOZ_OVERRIDE
{
bool unused;
return defineProperty(cx, proxy, id, desc, &unused);
}
virtual bool defineProperty(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
JS::MutableHandle<JSPropertyDescriptor> desc, bool* defined);
bool delete_(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::Handle<jsid> id, bool* bp) MOZ_OVERRIDE;
bool has(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id, bool* bp) MOZ_OVERRIDE;
bool isExtensible(JSContext *cx, JS::Handle<JSObject*> proxy, bool *extensible) MOZ_OVERRIDE;
static JSObject* GetExpandoObject(JSObject* obj)
{
MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
if (v.isObject()) {
return &v.toObject();
}
if (v.isUndefined()) {
return nullptr;
}
js::ExpandoAndGeneration* expandoAndGeneration =
static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
v = expandoAndGeneration->expando;
return v.isUndefined() ? nullptr : &v.toObject();
}
/* GetAndClearExpandoObject does not DROP or clear the preserving wrapper flag. */
static JSObject* GetAndClearExpandoObject(JSObject* obj);
static JSObject* EnsureExpandoObject(JSContext* cx,
JS::Handle<JSObject*> obj);
const DOMClass& mClass;
};
extern jsid s_length_id;
int32_t IdToInt32(JSContext* cx, JS::Handle<jsid> id);
// XXXbz this should really return uint32_t, with the maximum value
// meaning "not an index"...
inline int32_t
GetArrayIndexFromId(JSContext* cx, JS::Handle<jsid> id)
{
if (MOZ_LIKELY(JSID_IS_INT(id))) {
return JSID_TO_INT(id);
}
if (MOZ_LIKELY(id == s_length_id)) {
return -1;
}
if (MOZ_LIKELY(JSID_IS_ATOM(id))) {
JSAtom* atom = JSID_TO_ATOM(id);
jschar s = *js::GetAtomChars(atom);
if (MOZ_LIKELY((unsigned)s >= 'a' && (unsigned)s <= 'z'))
return -1;
uint32_t i;
JSLinearString* str = js::AtomToLinearString(JSID_TO_ATOM(id));
return js::StringIsArrayIndex(str, &i) ? i : -1;
}
return IdToInt32(cx, id);
}
inline bool
IsArrayIndex(int32_t index)
{
return index >= 0;
}
inline void
FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc, JSObject* obj, bool readonly)
{
desc.object().set(obj);
desc.setAttributes((readonly ? JSPROP_READONLY : 0) | JSPROP_ENUMERATE);
desc.setGetter(nullptr);
desc.setSetter(nullptr);
desc.setShortId(0);
}
inline void
FillPropertyDescriptor(JS::MutableHandle<JSPropertyDescriptor> desc, JSObject* obj, JS::Value v,
bool readonly)
{
desc.value().set(v);
FillPropertyDescriptor(desc, obj, readonly);
}
} // namespace dom
} // namespace mozilla
#endif /* mozilla_dom_DOMProxyHandler_h */