/*
 * Copyright (C) 2014 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.
 */

#include "config.h"
#include "WebSQLiteDatabaseTracker.h"

#include <WebCore/SQLiteDatabaseTracker.h>

namespace WebKit {
using namespace WebCore;

Ref<WebSQLiteDatabaseTracker> WebSQLiteDatabaseTracker::create(IsHoldingLockedFilesHandler&& isHoldingLockedFilesHandler)
{
    return adoptRef(*new WebSQLiteDatabaseTracker(WTF::move(isHoldingLockedFilesHandler)));
}

WebSQLiteDatabaseTracker::WebSQLiteDatabaseTracker(IsHoldingLockedFilesHandler&& isHoldingLockedFilesHandler)
    : m_isHoldingLockedFilesHandler(WTF::move(isHoldingLockedFilesHandler))
{
    ASSERT(RunLoop::isMain());
    SQLiteDatabaseTracker::setClient(this);
}

WebSQLiteDatabaseTracker::~WebSQLiteDatabaseTracker()
{
    ASSERT(RunLoop::isMain());
    SQLiteDatabaseTracker::setClient(nullptr);

    if (m_currentHystererisID)
        setIsHoldingLockedFiles(false);
}

void WebSQLiteDatabaseTracker::setIsSuspended(bool isSuspended)
{
    ASSERT(RunLoop::isMain());

    Locker locker { m_lock };
    m_isSuspended = isSuspended;
}

void WebSQLiteDatabaseTracker::willBeginFirstTransaction()
{
    Locker locker { m_lock };
    if (m_currentHystererisID) {
        // Cancel previous hysteresis task.
        ++m_currentHystererisID;
        return;
    }

    RunLoop::mainSingleton().dispatch([weakThis = WeakPtr { *this }] {
        if (RefPtr protectedThis = weakThis.get()) {
            Locker locker { protectedThis->m_lock };
            protectedThis->setIsHoldingLockedFiles(true);
        }
    });
}

void WebSQLiteDatabaseTracker::didFinishLastTransaction()
{
    Locker locker { m_lock };
    RunLoop::mainSingleton().dispatchAfter(1_s, [weakThis = WeakPtr { *this }, hystererisID = ++m_currentHystererisID] {
        RefPtr protectedThis = weakThis.get();
        if (!protectedThis)
            return;

        Locker locker { protectedThis->m_lock };
        if (protectedThis->m_currentHystererisID != hystererisID)
            return; // Cancelled.

        protectedThis->m_currentHystererisID = 0;
        protectedThis->setIsHoldingLockedFiles(false);
    });
}

void WebSQLiteDatabaseTracker::setIsHoldingLockedFiles(bool isHoldingLockedFiles)
{
    if (m_isSuspended)
        return;

    m_isHoldingLockedFilesHandler(isHoldingLockedFiles);
}

} // namespace WebKit
