/*

 * Copyright (C) 2010 Apple Inc. All rights reserved.

 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)

 *

 * 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 "UpdateChunk.h"

#include "ArgumentDecoder.h"

#include "ArgumentEncoder.h"

#include "Attachment.h"

#include "WebCoreArgumentCoders.h"

#include <QDebug>

#include <QFile>

#include <QImage>

#include <QTemporaryFile>

#include <WebCore/FloatRect.h>

#include <WebCore/PlatformString.h>

#include <wtf/Vector.h>

using namespace WebCore;

using namespace std;

namespace WebKit {

struct MappedMemory {

    QFile* file;

    uchar* data;

    size_t size;

    void markUsed() { *reinterpret_cast<uint64_t*>(data) = 0; }

    void markFree() { *reinterpret_cast<uint64_t*>(data) = 0xdeadbeef; }

    bool isFree() { return *reinterpret_cast<uint64_t*>(data) == 0xdeadbeef; }

};

static Vector<MappedMemory>* mmapPool;

static MappedMemory* mapMemory(size_t size)

{

    if (!mmapPool)

        mmapPool = new Vector<MappedMemory>;

    for (unsigned n = 0; n < mmapPool->size(); ++n) {

        MappedMemory& current = mmapPool->at(n);

        if (current.size >= size && current.isFree()) {

            current.markUsed();

            return &current;

        }

    }

    MappedMemory newMap;

    newMap.size = size;

    // FIXME: Clean up or reuse leftover map files from the disk.

    newMap.file = new QTemporaryFile("WebKit2UpdateChunk");

    newMap.file->open(QIODevice::ReadWrite);

    newMap.file->resize(newMap.size);

    newMap.data = newMap.file->map(0, newMap.size);

    newMap.file->close();

    newMap.markUsed();

    mmapPool->append(newMap);

    return &mmapPool->last();

}

static MappedMemory* mapFile(QString fileName, size_t size)

{

    if (!mmapPool)

        mmapPool = new Vector<MappedMemory>;

    for (unsigned n = 0; n < mmapPool->size(); ++n) {

        MappedMemory& current = mmapPool->at(n);

        if (current.file->fileName() == fileName) {

            ASSERT(!current.isFree());

            return &current;

        }

    }

    MappedMemory newMap;

    newMap.file = new QFile(fileName);

    if (!newMap.file->open(QIODevice::ReadWrite))

        return 0;

    newMap.data = newMap.file->map(0, size);

    ASSERT(!newMap.isFree());

    newMap.file->close();

    mmapPool->append(newMap);

    return &mmapPool->last();

}

UpdateChunk::UpdateChunk()

    : m_mappedMemory(0)

{

}

UpdateChunk::UpdateChunk(const IntRect& rect)

    : m_rect(rect)

    , m_mappedMemory(mapMemory(size()))

{

}

UpdateChunk::~UpdateChunk()

{

    if (m_mappedMemory)

        m_mappedMemory->markFree();

}

uint8_t* UpdateChunk::data()

{

    ASSERT(m_mappedMemory);

    ASSERT(m_mappedMemory->data);

    return reinterpret_cast<uint8_t*>(m_mappedMemory->data);

}

void UpdateChunk::encode(CoreIPC::ArgumentEncoder& encoder) const

{

    encoder.encode(m_rect);

    encoder.encode(String(m_mappedMemory->file->fileName()));

    m_mappedMemory = 0;

}

bool UpdateChunk::decode(CoreIPC::ArgumentDecoder& decoder, UpdateChunk& chunk)

{

    IntRect rect;

    if (!decoder.decode(rect))

        return false;

    chunk.m_rect = rect;

    String fileName;

    if (!decoder.decode(fileName))

        return false;

    chunk.m_mappedMemory = mapFile(fileName, chunk.size());

    return chunk.m_mappedMemory->data;

}

QImage UpdateChunk::createImage()

{

    return QImage(data(), m_rect.width(), m_rect.height(), QImage::Format_RGB32);

}

} // namespace WebKit