varint.con commit rebase: prepare to do generic housekeeping (f5f758a)
   1#include "varint.h"
   2
   3uintmax_t decode_varint(const unsigned char **bufp)
   4{
   5        const unsigned char *buf = *bufp;
   6        unsigned char c = *buf++;
   7        uintmax_t val = c & 127;
   8        while (c & 128) {
   9                val += 1;
  10                if (!val || MSB(val, 7))
  11                        return 0; /* overflow */
  12                c = *buf++;
  13                val = (val << 7) + (c & 127);
  14        }
  15        *bufp = buf;
  16        return val;
  17}
  18
  19int encode_varint(uintmax_t value, unsigned char *buf)
  20{
  21        unsigned char varint[16];
  22        unsigned pos = sizeof(varint) - 1;
  23        varint[pos] = value & 127;
  24        while (value >>= 7)
  25                varint[--pos] = 128 | (--value & 127);
  26        if (buf)
  27                memcpy(buf, varint + pos, sizeof(varint) - pos);
  28        return sizeof(varint) - pos;
  29}