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/* See LICENSE file for copyright and license details. */
#include "stream.h"
#include "util.h"
#include <string.h>
#include <unistd.h>
USAGE("")
static size_t
compare(const char *restrict new, const char *restrict old, size_t n, size_t **cmp, size_t *cmpsize)
{
size_t i, start1, start2, ptr, same, diff;
for (ptr = i = 0; i < n;) {
for (start1 = i; i < n && old[i] == new[i]; i++);
for (start2 = i; i < n && old[i] != new[i]; i++);
same = start2 - start1;
diff = i - start2;
if (ptr && same < 2 * sizeof(size_t) && same + diff <= SIZE_MAX - (*cmp)[ptr - 1]) {
(*cmp)[ptr - 1] += same + diff;
} else {
if (ptr + 2 > *cmpsize)
*cmp = erealloc(*cmp, (*cmpsize += 128) * sizeof(size_t));
(*cmp)[ptr++] = same;
(*cmp)[ptr++] = diff;
}
}
return ptr;
}
int
main(int argc, char *argv[])
{
struct stream stream;
char *buf[2];
size_t n, parts, part, off;
int i;
size_t *cmp = NULL;
size_t cmpsize = 0;
UNOFLAGS(argc);
eopen_stream(&stream, NULL);
fprint_stream_head(stdout, &stream);
efflush(stdout, "<stdout>");
echeck_frame_size(stream.width, stream.height, stream.pixel_size, 0, "<stdin>");
n = stream.width * stream.height * stream.pixel_size;
buf[0] = emalloc(n);
buf[1] = ecalloc(1, n);
for (i = 0; eread_frame(&stream, buf[i], n); i ^= 1) {
parts = compare(buf[i], buf[i ^ 1], n, &cmp, &cmpsize);
for (off = part = 0; part < parts; part += 2) {
off += cmp[part];
ewriteall(STDOUT_FILENO, cmp + part, 2 * sizeof(size_t), "<stdout>");
ewriteall(STDOUT_FILENO, buf[i] + off, cmp[part + 1], "<stdout>");
off += cmp[part + 1];
}
}
free(cmp);
free(buf[0]);
free(buf[1]);
return 0;
}
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