Files
adsb-tools/common.c
2016-02-14 22:26:34 +00:00

69 lines
1.3 KiB
C

#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "common.h"
ssize_t buf_fill(struct buf *buf, int fd) {
if (buf->start + buf->length == BUF_LEN_MAX) {
assert(buf->start > 0);
memmove(buf->buf, buf_at(buf, 0), buf->length);
buf->start = 0;
}
size_t space = BUF_LEN_MAX - buf->length - buf->start;
ssize_t in = read(fd, buf_at(buf, buf->length), space);
if (in < 0) {
return in;
}
buf->length += in;
return in;
}
void buf_consume(struct buf *buf, size_t length) {
assert(buf->length >= length);
buf->length -= length;
if (buf->length) {
buf->start += length;
} else {
buf->start = 0;
}
}
static uint8_t hex_table[256] = {0};
void hex_init() {
for (int i = '0'; i <= '9'; i++) {
hex_table[i] = i - '0';
}
for (int i = 'a'; i <= 'f'; i++) {
hex_table[i] = 10 + i - 'a';
}
for (int i = 'A'; i <= 'F'; i++) {
hex_table[i] = 10 + i - 'A';
}
}
void hex_to_bin(char *out, char *in, size_t bytes) {
uint8_t *in2 = (uint8_t *) in;
for (size_t i = 0, j = 0; i < bytes; i++, j += 2) {
out[i] = (hex_table[in2[j]] << 4) | hex_table[in2[j + 1]];
}
}
uint64_t hex_to_int(char *in, size_t bytes) {
uint8_t *in2 = (uint8_t *) in;
uint64_t ret = 0;
bytes *= 2;
for (size_t i = 0; i < bytes; i++) {
ret <<= 4;
ret |= hex_table[in2[i]];
}
return ret;
}