diff options
Diffstat (limited to 'varint.c')
-rw-r--r-- | varint.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/varint.c b/varint.c new file mode 100644 index 0000000000..4ed7729496 --- /dev/null +++ b/varint.c @@ -0,0 +1,29 @@ +#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; +} |