git-commit-vandalism/test-delta.c
Linus Torvalds 75c42d8cc3 Add a "max_size" parameter to diff_delta()
Anything that generates a delta to see if two objects are close usually
isn't interested in the delta ends up being bigger than some specified
size, and this allows us to stop delta generation early when that
happens.
2005-06-25 19:30:20 -07:00

82 lines
1.8 KiB
C

/*
* test-delta.c: test code to exercise diff-delta.c and patch-delta.c
*
* (C) 2005 Nicolas Pitre <nico@cam.org>
*
* This code is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include "delta.h"
static const char *usage =
"test-delta (-d|-p) <from_file> <data_file> <out_file>";
int main(int argc, char *argv[])
{
int fd;
struct stat st;
void *from_buf, *data_buf, *out_buf;
unsigned long from_size, data_size, out_size;
if (argc != 5 || (strcmp(argv[1], "-d") && strcmp(argv[1], "-p"))) {
fprintf(stderr, "Usage: %s\n", usage);
return 1;
}
fd = open(argv[2], O_RDONLY);
if (fd < 0 || fstat(fd, &st)) {
perror(argv[2]);
return 1;
}
from_size = st.st_size;
from_buf = mmap(NULL, from_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (from_buf == MAP_FAILED) {
perror(argv[2]);
return 1;
}
close(fd);
fd = open(argv[3], O_RDONLY);
if (fd < 0 || fstat(fd, &st)) {
perror(argv[3]);
return 1;
}
data_size = st.st_size;
data_buf = mmap(NULL, data_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (data_buf == MAP_FAILED) {
perror(argv[3]);
return 1;
}
close(fd);
if (argv[1][1] == 'd')
out_buf = diff_delta(from_buf, from_size,
data_buf, data_size,
&out_size, ~0UL);
else
out_buf = patch_delta(from_buf, from_size,
data_buf, data_size,
&out_size);
if (!out_buf) {
fprintf(stderr, "delta operation failed (returned NULL)\n");
return 1;
}
fd = open (argv[4], O_WRONLY|O_CREAT|O_TRUNC, 0666);
if (fd < 0 || write(fd, out_buf, out_size) != out_size) {
perror(argv[4]);
return 1;
}
return 0;
}