MultiMC5/depends/lzma/wrapper/lzip_header.c

97 lines
2.1 KiB
C

#include "lzip_header.h"
#include <string.h>
#define ELZMA_LZIP_HEADER_SIZE 6
#define ELZMA_LZIP_FOOTER_SIZE 12
static void initLzipHeader(struct elzma_file_header *hdr)
{
memset((void *)hdr, 0, sizeof(struct elzma_file_header));
}
static int parseLzipHeader(const unsigned char *hdrBuf, struct elzma_file_header *hdr)
{
if (0 != strncmp("LZIP", (char *)hdrBuf, 4))
return 1;
/* XXX: ignore version for now */
hdr->pb = 2;
hdr->lp = 0;
hdr->lc = 3;
/* unknown at this point */
hdr->isStreamed = 1;
hdr->uncompressedSize = 0;
hdr->dictSize = 1 << (hdrBuf[5] & 0x1F);
return 0;
}
static int serializeLzipHeader(unsigned char *hdrBuf, const struct elzma_file_header *hdr)
{
hdrBuf[0] = 'L';
hdrBuf[1] = 'Z';
hdrBuf[2] = 'I';
hdrBuf[3] = 'P';
hdrBuf[4] = 0;
{
int r = 0;
while ((hdr->dictSize >> r) != 0)
r++;
hdrBuf[5] = (unsigned char)(r - 1) & 0x1F;
}
return 0;
}
static int serializeLzipFooter(struct elzma_file_footer *ftr, unsigned char *ftrBuf)
{
unsigned int i = 0;
/* first crc32 */
for (i = 0; i < 4; i++)
{
*(ftrBuf++) = (unsigned char)(ftr->crc32 >> (i * 8));
}
/* next data size */
for (i = 0; i < 8; i++)
{
*(ftrBuf++) = (unsigned char)(ftr->uncompressedSize >> (i * 8));
}
/* write version 0 files, omit member length for now*/
return 0;
}
static int parseLzipFooter(const unsigned char *ftrBuf, struct elzma_file_footer *ftr)
{
unsigned int i = 0;
ftr->crc32 = 0;
ftr->uncompressedSize = 0;
/* first crc32 */
for (i = 0; i < 4; i++)
{
ftr->crc32 += ((unsigned int)*(ftrBuf++) << (i * 8));
}
/* next data size */
for (i = 0; i < 8; i++)
{
ftr->uncompressedSize += (unsigned long long)*(ftrBuf++) << (i * 8);
}
/* read version 0 files, omit member length for now*/
return 0;
}
void initializeLZIPFormatHandler(struct elzma_format_handler *hand)
{
hand->header_size = ELZMA_LZIP_HEADER_SIZE;
hand->init_header = initLzipHeader;
hand->parse_header = parseLzipHeader;
hand->serialize_header = serializeLzipHeader;
hand->footer_size = ELZMA_LZIP_FOOTER_SIZE;
hand->serialize_footer = serializeLzipFooter;
hand->parse_footer = parseLzipFooter;
}