David Aguilar | 1c4b660 | 2014-09-14 00:40:45 -0700 | [diff] [blame] | 1 | #include "git-compat-util.h" |
Junio C Hamano | d2c1898 | 2012-04-03 15:53:08 -0700 | [diff] [blame] | 2 | #include "varint.h" |
| 3 | |
| 4 | uintmax_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 | |
| 20 | int 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 | } |