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#include "musicbrainz/crc.h"
#include "musicbrainz/gzip.h"
inline QByteArray render32BitInt(unsigned long value)
{
unsigned char data[4];
data[0] = (value ) & 255;
data[1] = (value >> 8) & 255;
data[2] = (value >> 16) & 255;
data[3] = (value >> 24) & 255;
return QByteArray((char *)data, 4);
}
inline unsigned long calculateCrc32(const QByteArray &data)
{
crc_t crc;
crc = crc_init();
crc = crc_update(crc, (unsigned char *)data.data(), data.size());
crc = crc_finalize(crc);
return crc;
}
QByteArray gzipCompress(const QByteArray &data)
{
const unsigned char header[10] = {
0x1f, 0x8b, // ID1 + ID2
8, // Compression Method
0, // Flags
0, 0, 0, 0, // Modification Time
2, // Extra Flags
255, // Operating System
};
QByteArray compressedData = qCompress(data);
compressedData.remove(0, 6); // Qt size + zlib header
compressedData.remove(compressedData.size() - 4, 4); // zlib footer
QByteArray result;
result.append(reinterpret_cast<const char*>(header), 10);
result.append(compressedData);
result.append(render32BitInt(calculateCrc32(data)));
result.append(render32BitInt(data.size()));
return result;
}
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