GZIP.cpp

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/****************************************************************************
 ** Makou Reactor Final Fantasy VII Field Script Editor
 ** Copyright (C) 2009-2012 Arzel Jérôme <myst6re@gmail.com>
 **
 ** This program is free software: you can redistribute it and/or modify
 ** it under the terms of the GNU General Public License as published by
 ** the Free Software Foundation, either version 3 of the License, or
 ** (at your option) any later version.
 **
 ** This program is distributed in the hope that it will be useful,
 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ** GNU General Public License for more details.
 **
 ** You should have received a copy of the GNU General Public License
 ** along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ****************************************************************************/
#include "GZIP.h"
#include <zlib.h>
#undef compress // conflict with GZIP::compress

QByteArray GZIP::decompress(const QByteArray &data, int decSize, Strategy strategy)
{
    return decompress(data.constData(), data.size(), decSize, strategy);
}

QByteArray GZIP::compress(const QByteArray &ungzip, int level, Strategy strategy)
{
    return compress(ungzip.constData(), ungzip.size(), level, strategy);
}

QByteArray GZIP::decompress(const char *data, int size, int decSize, Strategy strategy)
{
    QTemporaryFile temp;
    if(!temp.open()) {
        return QByteArray();
    }
    temp.write(data, size);
    temp.close();

    return decompress(temp.fileName(), decSize, strategy);
}

QByteArray GZIP::compress(const char *ungzip, int size, int level, Strategy strategy)
{
    QString tempPath = QDir::tempPath() + "/qt_temp.gz";

    gzFile file2 = gzopen(tempPath.toLatin1(), gzMode("w", level, strategy).toLatin1());
    if(!file2) {
        return QByteArray();
    }
    gzwrite(file2, ungzip, size);
    gzclose(file2);
    QFile finalFile(tempPath);
    if(!finalFile.open(QIODevice::ReadOnly)) {
        return QByteArray();
    }

    QByteArray data = finalFile.readAll();
    finalFile.remove();

    return data;
}

QByteArray GZIP::decompress(const QString &path, int decSize, Strategy strategy)
{
    Q_UNUSED(decSize);
    QByteArray ungzip;

    gzFile file = gzopen(path.toLatin1(), gzMode("r", -1, strategy).toLatin1());
    if(!file) {
        return QByteArray();
    }
    char buffer[10000];
    int r;
    while((r = gzread(file, buffer, 10000)) > 0) {
        ungzip.append(buffer, r);
    }
    gzclose(file);

    return ungzip;
}

char GZIP::strategyToChar(Strategy strategy)
{
    switch (strategy) {
    case StrategyDefault:     return '*';
    case StrategyFiltered:    return 'f';
    case StrategyHuffmanOnly: return 'h';
    case StrategyRle:         return 'R';
    case StrategyFixed:       return 'F';
    }
    return '*';
}

QString GZIP::gzMode(const char *mode, int level, Strategy strategy)
{
    QString m(mode);
    if (level >= 0 && level <= 9) {
        m.append(QString::number(level));
    }
    char s = strategyToChar(strategy);
    if (s != '*') {
        m.append(s);
    }
    return m;
}