1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/jscompartmentinlines.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,109 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef jscompartmentinlines_h
1.11 +#define jscompartmentinlines_h
1.12 +
1.13 +#include "jscompartment.h"
1.14 +
1.15 +#include "gc/Barrier-inl.h"
1.16 +
1.17 +inline void
1.18 +JSCompartment::initGlobal(js::GlobalObject &global)
1.19 +{
1.20 + JS_ASSERT(global.compartment() == this);
1.21 + JS_ASSERT(!global_);
1.22 + global_ = &global;
1.23 +}
1.24 +
1.25 +js::GlobalObject *
1.26 +JSCompartment::maybeGlobal() const
1.27 +{
1.28 + JS_ASSERT_IF(global_, global_->compartment() == this);
1.29 + return global_;
1.30 +}
1.31 +
1.32 +js::AutoCompartment::AutoCompartment(ExclusiveContext *cx, JSObject *target)
1.33 + : cx_(cx),
1.34 + origin_(cx->compartment_)
1.35 +{
1.36 + cx_->enterCompartment(target->compartment());
1.37 +}
1.38 +
1.39 +js::AutoCompartment::AutoCompartment(ExclusiveContext *cx, JSCompartment *target)
1.40 + : cx_(cx),
1.41 + origin_(cx_->compartment_)
1.42 +{
1.43 + cx_->enterCompartment(target);
1.44 +}
1.45 +
1.46 +js::AutoCompartment::~AutoCompartment()
1.47 +{
1.48 + cx_->leaveCompartment(origin_);
1.49 +}
1.50 +
1.51 +inline bool
1.52 +JSCompartment::wrap(JSContext *cx, JS::MutableHandleValue vp, JS::HandleObject existing)
1.53 +{
1.54 + JS_ASSERT_IF(existing, vp.isObject());
1.55 +
1.56 + /* Only GC things have to be wrapped or copied. */
1.57 + if (!vp.isMarkable())
1.58 + return true;
1.59 +
1.60 + /* Handle strings. */
1.61 + if (vp.isString()) {
1.62 + JS::RootedString str(cx, vp.toString());
1.63 + if (!wrap(cx, str.address()))
1.64 + return false;
1.65 + vp.setString(str);
1.66 + return true;
1.67 + }
1.68 +
1.69 + JS_ASSERT(vp.isObject());
1.70 +
1.71 + /*
1.72 + * All that's left are objects.
1.73 + *
1.74 + * Object wrapping isn't the fastest thing in the world, in part because
1.75 + * we have to unwrap and invoke the prewrap hook to find the identity
1.76 + * object before we even start checking the cache. Neither of these
1.77 + * operations are needed in the common case, where we're just wrapping
1.78 + * a plain JS object from the wrappee's side of the membrane to the
1.79 + * wrapper's side.
1.80 + *
1.81 + * To optimize this, we note that the cache should only ever contain
1.82 + * identity objects - that is to say, objects that serve as the
1.83 + * canonical representation for a unique object identity observable by
1.84 + * script. Unwrap and prewrap are both steps that we take to get to the
1.85 + * identity of an incoming objects, and as such, they shuld never map
1.86 + * one identity object to another object. This means that we can safely
1.87 + * check the cache immediately, and only risk false negatives. Do this
1.88 + * in opt builds, and do both in debug builds so that we can assert
1.89 + * that we get the same answer.
1.90 + */
1.91 +#ifdef DEBUG
1.92 + JS::RootedObject cacheResult(cx);
1.93 +#endif
1.94 + JS::RootedValue v(cx, vp);
1.95 + if (js::WrapperMap::Ptr p = crossCompartmentWrappers.lookup(v)) {
1.96 +#ifdef DEBUG
1.97 + cacheResult = &p->value().get().toObject();
1.98 +#else
1.99 + vp.set(p->value());
1.100 + return true;
1.101 +#endif
1.102 + }
1.103 +
1.104 + JS::RootedObject obj(cx, &vp.toObject());
1.105 + if (!wrap(cx, &obj, existing))
1.106 + return false;
1.107 + vp.setObject(*obj);
1.108 + JS_ASSERT_IF(cacheResult, obj == cacheResult);
1.109 + return true;
1.110 +}
1.111 +
1.112 +#endif /* jscompartmentinlines_h */
