Merge branch 'fix'
[git/git.git] / delta.h
1 #ifndef DELTA_H
2 #define DELTA_H
3
4 /* handling of delta buffers */
5 extern void *diff_delta(const void *from_buf, unsigned long from_size,
6 const void *to_buf, unsigned long to_size,
7 unsigned long *delta_size, unsigned long max_size);
8 extern void *patch_delta(void *src_buf, unsigned long src_size,
9 const void *delta_buf, unsigned long delta_size,
10 unsigned long *dst_size);
11
12 /* 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 */
19 static inline unsigned long get_delta_hdr_size(const unsigned char **datap,
20 const unsigned char *top)
21 {
22 const unsigned char *data = *datap;
23 unsigned char cmd;
24 unsigned long size = 0;
25 int i = 0;
26 do {
27 cmd = *data++;
28 size |= (cmd & ~0x80) << i;
29 i += 7;
30 } while (cmd & 0x80 && data < top);
31 *datap = data;
32 return size;
33 }
34
35 #endif