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#include <stdio.h>
#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "bitsplit.h"
#include "util.h"
void bitsplit_init(struct bitsplit_state *s, int maxbits_in, int maxbits_out) {
assert(s && maxbits_in && maxbits_out);
assert(maxbits_in <= 8 && maxbits_out <= 8);
memset(s, 0, sizeof(struct bitsplit_state));
s->maxbits_in = maxbits_in;
s->maxbits_out = maxbits_out;
}
inline static int read_next_bit(struct bitsplit_state *s, uint8_t **src) {
assert(s);
if (!s->n_in) {
s->in = **src;
(*src)++;
s->n_in = s->maxbits_in;
}
return (s->in >> (-- (s->n_in))) & 1;
}
inline static void write_next_bit(struct bitsplit_state *s, uint8_t **dst, int bit) {
assert(s);
s->out = (s->out << 1) | (bit & 1);
s->n_out++;
if (s->n_out >= s->maxbits_out) {
**dst = s->out;
s->out = 0;
(*dst)++;
s->n_out = 0;
}
}
void bitsplit(struct bitsplit_state *s, uint8_t *src, size_t *src_l, uint8_t *dst, size_t *dst_l) {
uint8_t *save_dst = dst, *save_src = src;
assert(s && src && dst && src_l && dst_l);
while ((src < save_src+*src_l /*|| s->n_in*/) && (dst < save_dst+*dst_l /*|| s->n_out < s->maxbits_out*/)) {
int bit;
bit = read_next_bit(s, &src);
write_next_bit(s, &dst, bit);
}
*src_l = src - save_src;
*dst_l = dst - save_dst;
}
#if (TEST == 4)
int main(int argc, char *argv[]) {
struct bitsplit_state s;
assert(argc >= 3);
bitsplit_init(&s, atoi(argv[1]), atoi(argv[2]));
for (;;) {
uint8_t in[1024];
uint8_t *i;
ssize_t r;
r = read(0, in, sizeof(in));
assert(r >= 0);
if (r == 0)
break;
i = in;
while (r) {
uint8_t out[1024];
size_t outl = sizeof(out);
size_t il = r;
ssize_t r2;
bitsplit(&s, i, &il, out, &outl);
i += il;
r -= il;
if (outl) {
r2 = loop_write(1, out, outl);
assert(r2 > 0);
}
}
}
return 0;
}
#endif
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