/*

 * Copyright (C) 2010 Google, 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. ``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

 * 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.

 */

#ifndef HTMLParserScheduler_h

#define HTMLParserScheduler_h

#include "Timer.h"

#include <wtf/CurrentTime.h>

#include <wtf/Noncopyable.h>

namespace WebCore {

class HTMLDocumentParser;

class HTMLParserScheduler :  public Noncopyable {

public:

    HTMLParserScheduler(HTMLDocumentParser*);

    ~HTMLParserScheduler();

    struct PumpSession {

        PumpSession()

            : processedTokens(0)

            , startTime(currentTime())

        {

        }

        int processedTokens;

        double startTime;

    };

    // Inline as this is called after every token in the parser.

    bool shouldContinueParsing(PumpSession& session)

    {

        if (session.processedTokens > m_parserChunkSize) {

            session.processedTokens = 0;

            double elapsedTime = currentTime() - session.startTime;

            if (elapsedTime > m_parserTimeLimit) {

                // Schedule the parser to continue and yield from the parser.

                m_continueNextChunkTimer.startOneShot(0);

                return false;

            }

        }

        ++session.processedTokens;

        return true;

    }

    bool isScheduledForResume() const { return m_continueNextChunkTimer.isActive(); }

private:

    void continueNextChunkTimerFired(Timer<HTMLParserScheduler>*);

    HTMLDocumentParser* m_parser;

    double m_parserTimeLimit;

    int m_parserChunkSize;

    Timer<HTMLParserScheduler> m_continueNextChunkTimer;

};

}

#endif