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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=8 et ft=cpp : */
/* 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_hal_WindowIdentifier_h
#define mozilla_hal_WindowIdentifier_h
#include "mozilla/Types.h"
#include "nsCOMPtr.h"
#include "nsTArray.h"
class nsPIDOMWindowInner;
namespace mozilla {
namespace hal {
/**
* This class serves two purposes.
*
* First, this class wraps a pointer to a window.
*
* Second, WindowIdentifier lets us uniquely identify a window across
* processes. A window exposes an ID which is unique only within its
* process. Thus to identify a window, we need to know the ID of the
* process which contains it. But the scope of a process's ID is its
* parent; that is, two processes with different parents might have
* the same ID.
*
* So to identify a window, we need its ID plus the IDs of all the
* processes in the path from the window's process to the root
* process. We throw in the IDs of the intermediate windows (a
* content window is contained in a window at each level of the
* process tree) for good measures.
*
* You can access this list of IDs by calling AsArray().
*/
class WindowIdentifier {
public:
/**
* Create an empty WindowIdentifier. Calls to any of this object's
* public methods will assert -- an empty WindowIdentifier may be
* used only as a placeholder to code which promises not to touch
* the object.
*/
WindowIdentifier();
/**
* Wrap the given window in a WindowIdentifier. These two
* constructors automatically grab the window's ID and append it to
* the array of IDs.
*
* Note that these constructors allow an implicit conversion to a
* WindowIdentifier.
*/
explicit WindowIdentifier(nsPIDOMWindowInner* window);
/**
* Create a new WindowIdentifier with the given id array and window.
* This automatically grabs the window's ID and appends it to the
* array.
*/
WindowIdentifier(nsTArray<uint64_t>&& id, nsPIDOMWindowInner* window);
/**
* Get the list of window and process IDs we contain.
*/
typedef nsTArray<uint64_t> IDArrayType;
const IDArrayType& AsArray() const;
/**
* Append the ID of the ContentChild singleton to our array of
* window/process IDs.
*/
void AppendProcessID();
/**
* Does this WindowIdentifier identify both a window and the process
* containing that window? If so, we say it has traveled through
* IPC.
*/
bool HasTraveledThroughIPC() const;
/**
* Get the window this object wraps.
*/
nsPIDOMWindowInner* GetWindow() const;
private:
/**
* Get the ID of the window object we wrap.
*/
uint64_t GetWindowID() const;
AutoTArray<uint64_t, 3> mID;
nsCOMPtr<nsPIDOMWindowInner> mWindow;
#ifdef DEBUG
bool mIsEmpty = false;
#endif
};
} // namespace hal
} // namespace mozilla
#endif // mozilla_hal_WindowIdentifier_h