Andrew's git - gitweb.git/blob

   1#include "git-compat-util.h"
   2#include "varint.h"
   3
   4uintmax_t decode_varint(const unsigned char **bufp)
   5{
   6        const unsigned char *buf = *bufp;
   7        unsigned char c = *buf++;
   8        uintmax_t val = c & 127;
   9        while (c & 128) {
  10                val += 1;
  11                if (!val || MSB(val, 7))
  12                        return 0; /* overflow */
  13                c = *buf++;
  14                val = (val << 7) + (c & 127);
  15        }
  16        *bufp = buf;
  17        return val;
  18}
  19
  20int encode_varint(uintmax_t value, unsigned char *buf)
  21{
  22        unsigned char varint[16];
  23        unsigned pos = sizeof(varint) - 1;
  24        varint[pos] = value & 127;
  25        while (value >>= 7)
  26                varint[--pos] = 128 | (--value & 127);
  27        if (buf)
  28                memcpy(buf, varint + pos, sizeof(varint) - pos);
  29        return sizeof(varint) - pos;
  30}