commando.html5/node_modules/lnsocket/varint.c
Captain Nick Lucifer* a0bc2d79de dot.dot.dot.exampol
2023-03-10 23:21:16 +05:45

75 lines
1.3 KiB
C

#include "varint.h"
size_t varint_size(uint64_t v)
{
if (v < 0xfd)
return 1;
if (v <= 0xffff)
return 3;
if (v <= 0xffffffff)
return 5;
return 9;
}
size_t varint_put(unsigned char buf[VARINT_MAX_LEN], uint64_t v)
{
unsigned char *p = buf;
if (v < 0xfd) {
*(p++) = v;
} else if (v <= 0xffff) {
(*p++) = 0xfd;
(*p++) = v;
(*p++) = v >> 8;
} else if (v <= 0xffffffff) {
(*p++) = 0xfe;
(*p++) = v;
(*p++) = v >> 8;
(*p++) = v >> 16;
(*p++) = v >> 24;
} else {
(*p++) = 0xff;
(*p++) = v;
(*p++) = v >> 8;
(*p++) = v >> 16;
(*p++) = v >> 24;
(*p++) = v >> 32;
(*p++) = v >> 40;
(*p++) = v >> 48;
(*p++) = v >> 56;
}
return p - buf;
}
size_t varint_get(const unsigned char *p, size_t max, int64_t *val)
{
if (max < 1)
return 0;
switch (*p) {
case 0xfd:
if (max < 3)
return 0;
*val = ((uint64_t)p[2] << 8) + p[1];
return 3;
case 0xfe:
if (max < 5)
return 0;
*val = ((uint64_t)p[4] << 24) + ((uint64_t)p[3] << 16)
+ ((uint64_t)p[2] << 8) + p[1];
return 5;
case 0xff:
if (max < 9)
return 0;
*val = ((uint64_t)p[8] << 56) + ((uint64_t)p[7] << 48)
+ ((uint64_t)p[6] << 40) + ((uint64_t)p[5] << 32)
+ ((uint64_t)p[4] << 24) + ((uint64_t)p[3] << 16)
+ ((uint64_t)p[2] << 8) + p[1];
return 9;
default:
*val = *p;
return 1;
}
}