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#ifndef DELTA_H
#define DELTA_H
/* handling of delta buffers */
extern void *diff_delta(void *from_buf, unsigned long from_size,
void *to_buf, unsigned long to_size,
unsigned long *delta_size, unsigned long max_size);
extern void *patch_delta(void *src_buf, unsigned long src_size,
void *delta_buf, unsigned long delta_size,
unsigned long *dst_size);
/* the smallest possible delta size is 2 bytes (empty to empty) */
#define DELTA_SIZE_MIN 2
/*
* This must be called twice on the delta data buffer, first to get the
* expected reference buffer size, and again to get the result buffer size.
*/
static inline unsigned long get_delta_hdr_size(const unsigned char **datap)
{
const unsigned char *data = *datap;
unsigned char cmd = *data++;
unsigned long size = cmd & ~0x80;
int i = 7;
while (cmd & 0x80) {
cmd = *data++;
size |= (cmd & ~0x80) << i;
i += 7;
}
*datap = data;
return size;
}
#endif
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