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Nicolas Pitred1af0022005-05-20 16:59:17 -04001#ifndef DELTA_H
2#define DELTA_H
3
4/* handling of delta buffers */
Nicolas Pitrea310d432005-05-19 10:27:14 -04005extern void *diff_delta(void *from_buf, unsigned long from_size,
6 void *to_buf, unsigned long to_size,
Linus Torvalds75c42d82005-06-25 19:30:20 -07007 unsigned long *delta_size, unsigned long max_size);
Nicolas Pitrea310d432005-05-19 10:27:14 -04008extern void *patch_delta(void *src_buf, unsigned long src_size,
9 void *delta_buf, unsigned long delta_size,
10 unsigned long *dst_size);
Nicolas Pitred1af0022005-05-20 16:59:17 -040011
Nicolas Pitredcde55b2005-06-29 02:49:56 -040012/* the smallest possible delta size is 4 bytes */
13#define DELTA_SIZE_MIN 4
14
15/*
16 * This must be called twice on the delta data buffer, first to get the
17 * expected reference buffer size, and again to get the result buffer size.
18 */
19static inline unsigned long get_delta_hdr_size(const unsigned char **datap)
20{
21 const unsigned char *data = *datap;
22 unsigned char cmd = *data++;
23 unsigned long size = cmd & ~0x80;
24 int i = 7;
25 while (cmd & 0x80) {
26 cmd = *data++;
27 size |= (cmd & ~0x80) << i;
28 i += 7;
29 }
30 *datap = data;
31 return size;
32}
33
Nicolas Pitred1af0022005-05-20 16:59:17 -040034#endif