Files
damus/nostrdb/src/hex.h
William Casarin 1ffbd80c67 nostrdb: move everything to src
Signed-off-by: William Casarin <jb55@jb55.com>
2025-08-11 16:39:43 -07:00

69 lines
1.3 KiB
C

#ifndef HEX_H
#define HEX_H
#include <stdlib.h>
static const char hex_table[256] = {
['0'] = 0, ['1'] = 1, ['2'] = 2, ['3'] = 3,
['4'] = 4, ['5'] = 5, ['6'] = 6, ['7'] = 7,
['8'] = 8, ['9'] = 9, ['a'] = 10, ['b'] = 11,
['c'] = 12, ['d'] = 13, ['e'] = 14, ['f'] = 15,
['A'] = 10, ['B'] = 11, ['C'] = 12, ['D'] = 13,
['E'] = 14, ['F'] = 15
};
static inline int char_to_hex(unsigned char *val, unsigned char c)
{
if (hex_table[c] || c == '0') {
*val = hex_table[c];
return 1;
}
return 0;
}
static inline int hex_decode(const char *str, size_t slen, void *buf, size_t bufsize)
{
unsigned char v1, v2;
unsigned char *p = buf;
while (slen > 1) {
if (!char_to_hex(&v1, str[0]) || !char_to_hex(&v2, str[1]))
return 0;
if (!bufsize)
return 0;
*(p++) = (v1 << 4) | v2;
str += 2;
slen -= 2;
bufsize--;
}
return slen == 0 && bufsize == 0;
}
static inline char hexchar(unsigned int val)
{
if (val < 10)
return '0' + val;
if (val < 16)
return 'a' + val - 10;
abort();
}
static int hex_encode(const void *buf, size_t bufsize, char *dest)
{
size_t i;
for (i = 0; i < bufsize; i++) {
unsigned int c = ((const unsigned char *)buf)[i];
*(dest++) = hexchar(c >> 4);
*(dest++) = hexchar(c & 0xF);
}
*dest = '\0';
return 1;
}
#endif