dom/bindings/RemoteObjectProxy.h
author James Teh <jteh@mozilla.com>
Thu, 07 Mar 2019 18:10:13 +0000
changeset 520910 c26d4a8d43c4d0d6f6e13135b8f35924123fe99e
parent 519655 58405fa4f0d960b05cb4f16fbfd66bf816d5ee61
child 527131 427b854cdb1c47ce6a643f83245914d66dca4382
permissions -rw-r--r--
Bug 1527922: Ensure the Reload button is disabled when testing against blank tabs in the browser toolbar key nav tests. r=Gijs For a blank tab, the Reload button should be disabled. These tests depend on this. This seems to be true when setting the new tab page to blank in Firefox Options. However, when we open about:blank with BrowserTestUtils.withNewTab, this is unreliable. That is, sometimes the Reload button is enabled, sometimes it isn't. I don't understand why this happens. For the purposes of these tests, just force the Reload button to be disabled for new, blank tabs so we get consistent results. Differential Revision: https://phabricator.services.mozilla.com/D22449

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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_RemoteObjectProxy_h
#define mozilla_dom_RemoteObjectProxy_h

#include "js/Proxy.h"
#include "mozilla/dom/MaybeCrossOriginObject.h"
#include "mozilla/dom/PrototypeList.h"
#include "xpcpublic.h"

namespace mozilla {
namespace dom {

/**
 * Base class for RemoteObjectProxy. Implements the pieces of the handler that
 * don't depend on properties/methods of the specific WebIDL interface that this
 * proxy implements.
 */
class RemoteObjectProxyBase : public js::BaseProxyHandler,
                              public MaybeCrossOriginObjectMixins {
 protected:
  explicit constexpr RemoteObjectProxyBase(prototypes::ID aPrototypeID)
      : BaseProxyHandler(&sCrossOriginProxyFamily, false),
        mPrototypeID(aPrototypeID) {}

 public:
  bool finalizeInBackground(const JS::Value& priv) const final { return false; }

  // Standard internal methods
  bool getOwnPropertyDescriptor(
      JSContext* aCx, JS::Handle<JSObject*> aProxy, JS::Handle<jsid> aId,
      JS::MutableHandle<JS::PropertyDescriptor> aDesc) const override;
  bool ownPropertyKeys(JSContext* aCx, JS::Handle<JSObject*> aProxy,
                       JS::AutoIdVector& aProps) const override;
  bool defineProperty(JSContext* aCx, JS::Handle<JSObject*> aProxy,
                      JS::Handle<jsid> aId,
                      JS::Handle<JS::PropertyDescriptor> aDesc,
                      JS::ObjectOpResult& result) const final;
  bool delete_(JSContext* aCx, JS::Handle<JSObject*> aProxy,
               JS::Handle<jsid> aId, JS::ObjectOpResult& aResult) const final;

  bool getPrototype(JSContext* aCx, JS::Handle<JSObject*> aProxy,
                    JS::MutableHandle<JSObject*> aProtop) const final;
  bool setPrototype(JSContext* aCx, JS::Handle<JSObject*> aProxy,
                    JS::Handle<JSObject*> aProto,
                    JS::ObjectOpResult& aResult) const final;
  bool getPrototypeIfOrdinary(JSContext* aCx, JS::Handle<JSObject*> aProxy,
                              bool* aIsOrdinary,
                              JS::MutableHandle<JSObject*> aProtop) const final;

  bool preventExtensions(JSContext* aCx, JS::Handle<JSObject*> aProxy,
                         JS::ObjectOpResult& aResult) const final;
  bool isExtensible(JSContext* aCx, JS::Handle<JSObject*> aProxy,
                    bool* aExtensible) const final;

  bool get(JSContext* cx, JS::Handle<JSObject*> aProxy,
           JS::Handle<JS::Value> aReceiver, JS::Handle<jsid> aId,
           JS::MutableHandle<JS::Value> aVp) const final;
  bool set(JSContext* cx, JS::Handle<JSObject*> aProxy, JS::Handle<jsid> aId,
           JS::Handle<JS::Value> aValue, JS::Handle<JS::Value> aReceiver,
           JS::ObjectOpResult& aResult) const final;

  // SpiderMonkey extensions
  bool hasOwn(JSContext* aCx, JS::Handle<JSObject*> aProxy,
              JS::Handle<jsid> aId, bool* aBp) const override;
  bool getOwnEnumerablePropertyKeys(JSContext* aCx,
                                    JS::Handle<JSObject*> aProxy,
                                    JS::AutoIdVector& aProps) const override;
  const char* className(JSContext* aCx,
                        JS::Handle<JSObject*> aProxy) const final;

  bool isCallable(JSObject* aObj) const final { return false; }
  bool isConstructor(JSObject* aObj) const final { return false; }

  virtual void NoteChildren(JSObject* aProxy,
                            nsCycleCollectionTraversalCallback& aCb) const = 0;

  static void* GetNative(JSObject* aProxy) {
    return js::GetProxyPrivate(aProxy).toPrivate();
  }

  /**
   * Returns true if aProxy is a cross-process proxy that represents
   * an object implementing the WebIDL interface for aProtoID. aProxy
   * should be a proxy object.
   */
  static inline bool IsRemoteObjectProxy(JSObject* aProxy,
                                         prototypes::ID aProtoID) {
    const js::BaseProxyHandler* handler = js::GetProxyHandler(aProxy);
    return handler->family() == &sCrossOriginProxyFamily &&
           static_cast<const RemoteObjectProxyBase*>(handler)->mPrototypeID ==
               aProtoID;
  }

  /**
   * Returns true if aProxy is a cross-process proxy, no matter which
   * interface it represents.  aProxy should be a proxy object.
   */
  static inline bool IsRemoteObjectProxy(JSObject* aProxy) {
    const js::BaseProxyHandler* handler = js::GetProxyHandler(aProxy);
    return handler->family() == &sCrossOriginProxyFamily;
  }

 protected:
  /**
   * Gets an existing cached proxy object, or creates a new one and caches it.
   * aProxy will be null on failure. aNewObjectCreated is set to true if a new
   * object was created, callers probably need to addref the native in that
   * case. aNewObjectCreated can be true even if aProxy is null, if something
   * failed after creating the object.
   */
  void GetOrCreateProxyObject(JSContext* aCx, void* aNative,
                              const js::Class* aClasp,
                              JS::MutableHandle<JSObject*> aProxy,
                              bool& aNewObjectCreated) const;

  const prototypes::ID mPrototypeID;

  static const char sCrossOriginProxyFamily;
};

/**
 * Proxy handler for proxy objects that represent an object implementing a
 * WebIDL interface that has cross-origin accessible properties/methods, and
 * which lives in a different process. The WebIDL code generator will create
 * arrays of cross-origin accessible properties/methods that can be used as
 * arguments to this template.
 *
 * The properties and methods can be cached on a holder JSObject, stored in a
 * reserved slot on the proxy object.
 *
 * The proxy objects that use a handler derived from this one are stored in a
 * hash map in the JS compartment's private (@see
 * xpc::CompartmentPrivate::GetRemoteProxyMap).
 */
template <class Native, JSPropertySpec* P, JSFunctionSpec* F>
class RemoteObjectProxy : public RemoteObjectProxyBase {
 public:
  void finalize(JSFreeOp* aFop, JSObject* aProxy) const final {
    auto native = static_cast<Native*>(GetNative(aProxy));
    RefPtr<Native> self(dont_AddRef(native));
  }

  void GetProxyObject(JSContext* aCx, Native* aNative,
                      JS::MutableHandle<JSObject*> aProxy) const {
    bool objectCreated = false;
    GetOrCreateProxyObject(aCx, aNative, &sClass, aProxy, objectCreated);
    if (objectCreated) {
      NS_ADDREF(aNative);
    }
  }

 protected:
  using RemoteObjectProxyBase::RemoteObjectProxyBase;

 private:
  bool EnsureHolder(JSContext* aCx, JS::Handle<JSObject*> aProxy,
                    JS::MutableHandle<JSObject*> aHolder) const final {
    return MaybeCrossOriginObjectMixins::EnsureHolder(
        aCx, aProxy, /* slot = */ 0, P, F, aHolder);
  }

  static const js::Class sClass;
};

/**
 * Returns true if aObj is a cross-process proxy object that
 * represents an object implementing the WebIDL interface for
 * aProtoID.
 */
static inline bool IsRemoteObjectProxy(JSObject* aObj,
                                       prototypes::ID aProtoID) {
  if (!js::IsProxy(aObj)) {
    return false;
  }
  return RemoteObjectProxyBase::IsRemoteObjectProxy(aObj, aProtoID);
}

/**
 * Returns true if aObj is a cross-process proxy object, no matter
 * which WebIDL interface it corresponds to.
 */
static inline bool IsRemoteObjectProxy(JSObject* aObj) {
  if (!js::IsProxy(aObj)) {
    return false;
  }
  return RemoteObjectProxyBase::IsRemoteObjectProxy(aObj);
}

}  // namespace dom
}  // namespace mozilla

#endif /* mozilla_dom_RemoteObjectProxy_h */