Andrew's git - gitweb.git/blob

   1#ifndef DELTA_H
   2#define DELTA_H
   3
   4/* handling of delta buffers */
   5extern void *diff_delta(void *from_buf, unsigned long from_size,
   6                        void *to_buf, unsigned long to_size,
   7                        unsigned long *delta_size, unsigned long max_size);
   8extern void *patch_delta(void *src_buf, unsigned long src_size,
   9                         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 */
  19static 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