#include "git-compat-util.h"

#include "varint.h"

uintmax_t decode_varint(const unsigned char **bufp)

{

  const unsigned char *buf = *bufp;

  unsigned char c = *buf++;

  uintmax_t val = c & 127;

  while (c & 128) {

    val += 1;

    if (!val || MSB(val, 7))

      return 0; /* overflow */

    c = *buf++;

    val = (val << 7) + (c & 127);

  }

  *bufp = buf;

  return val;

}

int encode_varint(uintmax_t value, unsigned char *buf)

{

  unsigned char varint[16];

  unsigned pos = sizeof(varint) - 1;

  varint[pos] = value & 127;

  while (value >>= 7)

    varint[--pos] = 128 | (--value & 127);

  if (buf)

    memcpy(buf, varint + pos, sizeof(varint) - pos);

  return sizeof(varint) - pos;

}