tvl-depot/third_party/git/varint.c
Vincent Ambo 7ef0d62730 merge(third_party/git): Merge squashed git subtree at v2.23.0
Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'
2020-01-11 23:40:29 +00:00

30 lines
660 B
C

#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;
}