1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
#include "crc.h"
#include "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 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(header, 10);
result.append(compressedData);
result.append(render32BitInt(calculateCrc32(data)));
result.append(render32BitInt(data.size()));
return result;
}
|
