git-commit-vandalism/t/helper/test-delta.c

/*
 * test-delta.c: test code to exercise diff-delta.c and patch-delta.c
 *
 * (C) 2005 Nicolas Pitre <nico@fluxnic.net>
 *
 * 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 "git-compat-util.h"
#include "delta.h"
#include "cache.h"

static const char usage_str[] =
	"test-delta (-d|-p) <from_file> <data_file> <out_file>";

int cmd_main(int argc, const 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_str);
		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]);
		close(fd);
		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]);
		close(fd);
		return 1;
	}
	close(fd);

	if (argv[1][1] == 'd')
		out_buf = diff_delta(from_buf, from_size,
				     data_buf, data_size,
				     &out_size, 0);
	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_in_full(fd, out_buf, out_size) < 0) {
		perror(argv[4]);
		return 1;
	}

	return 0;
}