/*
 * Copyright (C) 2010 University of Szeged
 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
 * 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 UNIVERSITY OF SZEGED ``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 UNIVERSITY OF SZEGED 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.
 */

#include "MappedMemoryPool.h"

#include "StdLibExtras.h"
#include <QDir>
#include <QIODevice>
#include <QTemporaryFile>

namespace WebKit {

MappedMemoryPool::~MappedMemoryPool()
{
    clear();
}

void MappedMemoryPool::clear()
{
    for (unsigned n = 0; n < m_pool.size(); ++n) {
        MappedMemory& current = m_pool.at(n);
        if (!current.file)
            continue;
        current.file->remove();
        delete current.file;
    }
    m_pool.clear();
}

MappedMemory* MappedMemoryPool::mapMemory(size_t size)
{
    for (unsigned n = 0; n < m_pool.size(); ++n) {
        MappedMemory& current = m_pool.at(n);
        if (current.dataSize >= size && current.isFree()) {
            current.markUsed();
            return &current;
        }
    }

    MappedMemory newMap;
    newMap.dataSize = size;
    newMap.file = new QTemporaryFile(QDir::tempPath() + "/WebKit2UpdateChunk");
    newMap.file->open(QIODevice::ReadWrite);
    newMap.fileName = newMap.file->fileName();
    newMap.file->resize(newMap.mapSize());
    newMap.mappedBytes = newMap.file->map(0, newMap.mapSize());
    newMap.file->close();
    newMap.markUsed();
    m_pool.append(newMap);
    return &m_pool.last();
}

MappedMemory* MappedMemoryPool::mapFile(QString fileName, size_t size)
{
    for (unsigned n = 0; n < m_pool.size(); ++n) {
        MappedMemory& current = m_pool.at(n);
        if (current.fileName == fileName) {
            ASSERT(!current.isFree());
            return &current;
        }
    }

    MappedMemory newMap;
    newMap.file = new QFile(fileName);
    newMap.fileName = fileName;
    newMap.dataSize = size;
    ASSERT(newMap.file->exists());
    ASSERT(newMap.file->size() >= newMap.mapSize());
    newMap.file->open(QIODevice::ReadWrite);
    newMap.mappedBytes = newMap.file->map(0, newMap.mapSize());
    ASSERT(newMap.mappedBytes);
    ASSERT(!newMap.isFree());
    newMap.file->close();
    m_pool.append(newMap);
    return &m_pool.last();
}

} // namespace WebKit