Source/WebCore/page/GlobalWindowIdentifier.h

/*
 * Copyright (C) 2018 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "ProcessIdentifier.h"
#include <wtf/HashTraits.h>
#include <wtf/Hasher.h>
#include <wtf/ObjectIdentifier.h>

namespace WebCore {

struct WindowIdentifierType;
using WindowIdentifier = ObjectIdentifier<WindowIdentifierType>;

// Window identifier that is unique across all WebContent processes.
struct GlobalWindowIdentifier {
    ProcessIdentifier processIdentifier;
    WindowIdentifier windowIdentifier;

    friend bool operator==(const GlobalWindowIdentifier&, const GlobalWindowIdentifier&) = default;
};

inline void add(Hasher& hasher, const GlobalWindowIdentifier& identifier)
{
    add(hasher, identifier.processIdentifier, identifier.windowIdentifier);
}

} // namespace WebCore

namespace WTF {

struct GlobalWindowIdentifierHash {
    static unsigned hash(const WebCore::GlobalWindowIdentifier& key) { return computeHash(key); }
    static bool equal(const WebCore::GlobalWindowIdentifier& a, const WebCore::GlobalWindowIdentifier& b) { return a == b; }
    static const bool safeToCompareToEmptyOrDeleted = true;
};

template<> struct HashTraits<WebCore::GlobalWindowIdentifier> : GenericHashTraits<WebCore::GlobalWindowIdentifier> {
    static WebCore::GlobalWindowIdentifier emptyValue() { return { HashTraits<WebCore::ProcessIdentifier>::emptyValue(), HashTraits<WebCore::WindowIdentifier>::emptyValue() }; }
    static bool isEmptyValue(const WebCore::GlobalWindowIdentifier& value) { return value.windowIdentifier.isHashTableEmptyValue(); }

    static void constructDeletedValue(WebCore::GlobalWindowIdentifier& slot)
    {
        new (NotNull, &slot.processIdentifier) WebCore::ProcessIdentifier(WTF::HashTableDeletedValue);
        new (NotNull, &slot.windowIdentifier) WebCore::WindowIdentifier(WTF::HashTableDeletedValue);
    }
    static bool isDeletedValue(const WebCore::GlobalWindowIdentifier& slot) { return slot.windowIdentifier.isHashTableDeletedValue(); }
};

template<> struct DefaultHash<WebCore::GlobalWindowIdentifier> : GlobalWindowIdentifierHash { };

} // namespace WTF