1 3b0f3d61 2020-01-22 neels /* Commandline diff utility to test diff implementations. */
  2 3b0f3d61 2020-01-22 neels /*
  3 3b0f3d61 2020-01-22 neels  * Copyright (c) 2018 Martin Pieuchot
  4 3b0f3d61 2020-01-22 neels  * Copyright (c) 2020 Neels Hofmeyr <neels@hofmeyr.de>
  5 3b0f3d61 2020-01-22 neels  *
  6 3b0f3d61 2020-01-22 neels  * Permission to use, copy, modify, and distribute this software for any
  7 3b0f3d61 2020-01-22 neels  * purpose with or without fee is hereby granted, provided that the above
  8 3b0f3d61 2020-01-22 neels  * copyright notice and this permission notice appear in all copies.
  9 3b0f3d61 2020-01-22 neels  *
 10 3b0f3d61 2020-01-22 neels  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 11 3b0f3d61 2020-01-22 neels  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 12 3b0f3d61 2020-01-22 neels  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 13 3b0f3d61 2020-01-22 neels  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 14 3b0f3d61 2020-01-22 neels  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 15 3b0f3d61 2020-01-22 neels  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 16 3b0f3d61 2020-01-22 neels  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 17 3b0f3d61 2020-01-22 neels  */
 18 3b0f3d61 2020-01-22 neels 
 19 3b0f3d61 2020-01-22 neels #include <sys/mman.h>
 20 3b0f3d61 2020-01-22 neels #include <sys/stat.h>
 21 3b0f3d61 2020-01-22 neels 
 22 3b0f3d61 2020-01-22 neels #include <err.h>
 23 3b0f3d61 2020-01-22 neels #include <fcntl.h>
 24 3b0f3d61 2020-01-22 neels #include <inttypes.h>
 25 3b0f3d61 2020-01-22 neels #include <stdio.h>
 26 3b0f3d61 2020-01-22 neels #include <stdlib.h>
 27 e10a628a 2020-09-16 stsp #include <stdbool.h>
 28 3e6cba3a 2020-08-13 stsp #include <string.h>
 29 3b0f3d61 2020-01-22 neels #include <unistd.h>
 30 3b0f3d61 2020-01-22 neels 
 31 e10a628a 2020-09-16 stsp #include <diff/arraylist.h>
 32 8ad022d2 2020-05-05 neels #include <diff/diff_main.h>
 33 8ad022d2 2020-05-05 neels #include <diff/diff_output.h>
 34 8ad022d2 2020-05-05 neels 
 35 3b0f3d61 2020-01-22 neels #ifdef __linux__
 36 3b0f3d61 2020-01-22 neels /* stupid shims to compile and test on linux */
 37 3b0f3d61 2020-01-22 neels #define __dead
 38 3b0f3d61 2020-01-22 neels 
 39 3b0f3d61 2020-01-22 neels static const char *getprogname()
 40 3b0f3d61 2020-01-22 neels {
 41 3b0f3d61 2020-01-22 neels 	return "diff";
 42 3b0f3d61 2020-01-22 neels }
 43 3b0f3d61 2020-01-22 neels #endif
 44 3b0f3d61 2020-01-22 neels 
 45 3b0f3d61 2020-01-22 neels __dead void	 usage(void);
 46 3b0f3d61 2020-01-22 neels int		 diffreg(char *, char *, int);
 47 c6eecea3 2020-07-26 stsp int		 openfile(const char *, char **, struct stat *);
 48 3b0f3d61 2020-01-22 neels 
 49 3b0f3d61 2020-01-22 neels __dead void
 50 3b0f3d61 2020-01-22 neels usage(void)
 51 3b0f3d61 2020-01-22 neels {
 52 760fe30e 2020-05-05 neels 	fprintf(stderr,
 53 760fe30e 2020-05-05 neels 		"usage: %s [-p] file1 file2\n"
 54 760fe30e 2020-05-05 neels 		"\n"
 55 760fe30e 2020-05-05 neels 		"  -p   Use Patience Diff (slower but often nicer)\n"
 56 760fe30e 2020-05-05 neels 		, getprogname());
 57 3b0f3d61 2020-01-22 neels 	exit(1);
 58 3b0f3d61 2020-01-22 neels }
 59 3b0f3d61 2020-01-22 neels 
 60 760fe30e 2020-05-05 neels static bool do_patience = false;
 61 760fe30e 2020-05-05 neels 
 62 3b0f3d61 2020-01-22 neels int
 63 3b0f3d61 2020-01-22 neels main(int argc, char *argv[])
 64 3b0f3d61 2020-01-22 neels {
 65 3e6cba3a 2020-08-13 stsp 	int ch, rc;
 66 3b0f3d61 2020-01-22 neels 
 67 760fe30e 2020-05-05 neels 	while ((ch = getopt(argc, argv, "p")) != -1) {
 68 3b0f3d61 2020-01-22 neels 		switch (ch) {
 69 760fe30e 2020-05-05 neels 		case 'p':
 70 760fe30e 2020-05-05 neels 			do_patience = true;
 71 760fe30e 2020-05-05 neels 			break;
 72 3b0f3d61 2020-01-22 neels 		default:
 73 3b0f3d61 2020-01-22 neels 			usage();
 74 3b0f3d61 2020-01-22 neels 		}
 75 3b0f3d61 2020-01-22 neels 	}
 76 3b0f3d61 2020-01-22 neels 
 77 3b0f3d61 2020-01-22 neels 	argc -= optind;
 78 3b0f3d61 2020-01-22 neels 	argv += optind;
 79 3b0f3d61 2020-01-22 neels 
 80 3b0f3d61 2020-01-22 neels 	if (argc != 2)
 81 3b0f3d61 2020-01-22 neels 		usage();
 82 3b0f3d61 2020-01-22 neels 
 83 3e6cba3a 2020-08-13 stsp 	rc = diffreg(argv[0], argv[1], 0);
 84 3e6cba3a 2020-08-13 stsp 	if (rc != DIFF_RC_OK) {
 85 3e6cba3a 2020-08-13 stsp 		fprintf(stderr, "diff: %s\n", strerror(rc));
 86 3e6cba3a 2020-08-13 stsp 		return 1;
 87 3e6cba3a 2020-08-13 stsp 	}
 88 3e6cba3a 2020-08-13 stsp 	return 0;
 89 3b0f3d61 2020-01-22 neels }
 90 3b0f3d61 2020-01-22 neels 
 91 0d27172a 2020-05-06 neels const struct diff_algo_config myers_then_patience;
 92 0d27172a 2020-05-06 neels const struct diff_algo_config myers_then_myers_divide;
 93 0d27172a 2020-05-06 neels const struct diff_algo_config patience;
 94 0d27172a 2020-05-06 neels const struct diff_algo_config myers_divide;
 95 3b0f3d61 2020-01-22 neels 
 96 760fe30e 2020-05-05 neels const struct diff_algo_config myers_then_patience = (struct diff_algo_config){
 97 3b0f3d61 2020-01-22 neels 	.impl = diff_algo_myers,
 98 9e668157 2020-01-27 neels 	.permitted_state_size = 1024 * 1024 * sizeof(int),
 99 3b0f3d61 2020-01-22 neels 	.fallback_algo = &patience,
100 3b0f3d61 2020-01-22 neels };
101 3b0f3d61 2020-01-22 neels 
102 0d27172a 2020-05-06 neels const struct diff_algo_config myers_then_myers_divide =
103 0d27172a 2020-05-06 neels 	(struct diff_algo_config){
104 760fe30e 2020-05-05 neels 	.impl = diff_algo_myers,
105 760fe30e 2020-05-05 neels 	.permitted_state_size = 1024 * 1024 * sizeof(int),
106 760fe30e 2020-05-05 neels 	.fallback_algo = &myers_divide,
107 760fe30e 2020-05-05 neels };
108 760fe30e 2020-05-05 neels 
109 3b0f3d61 2020-01-22 neels const struct diff_algo_config patience = (struct diff_algo_config){
110 3b0f3d61 2020-01-22 neels 	.impl = diff_algo_patience,
111 0d27172a 2020-05-06 neels 	/* After subdivision, do Patience again: */
112 0d27172a 2020-05-06 neels 	.inner_algo = &patience,
113 0d27172a 2020-05-06 neels 	/* If subdivision failed, do Myers Divide et Impera: */
114 0d27172a 2020-05-06 neels 	.fallback_algo = &myers_then_myers_divide,
115 3b0f3d61 2020-01-22 neels };
116 3b0f3d61 2020-01-22 neels 
117 3b0f3d61 2020-01-22 neels const struct diff_algo_config myers_divide = (struct diff_algo_config){
118 3b0f3d61 2020-01-22 neels 	.impl = diff_algo_myers_divide,
119 0d27172a 2020-05-06 neels 	/* When division succeeded, start from the top: */
120 0d27172a 2020-05-06 neels 	.inner_algo = &myers_then_myers_divide,
121 0d27172a 2020-05-06 neels 	/* (fallback_algo = NULL implies diff_algo_none). */
122 3b0f3d61 2020-01-22 neels };
123 3b0f3d61 2020-01-22 neels 
124 3b0f3d61 2020-01-22 neels const struct diff_config diff_config = {
125 3b0f3d61 2020-01-22 neels 	.atomize_func = diff_atomize_text_by_line,
126 760fe30e 2020-05-05 neels 	.algo = &myers_then_myers_divide,
127 3b0f3d61 2020-01-22 neels };
128 3b0f3d61 2020-01-22 neels 
129 760fe30e 2020-05-05 neels const struct diff_config diff_config_patience = {
130 760fe30e 2020-05-05 neels 	.atomize_func = diff_atomize_text_by_line,
131 760fe30e 2020-05-05 neels 	.algo = &myers_then_patience,
132 760fe30e 2020-05-05 neels };
133 760fe30e 2020-05-05 neels 
134 3b0f3d61 2020-01-22 neels int
135 3b0f3d61 2020-01-22 neels diffreg(char *file1, char *file2, int flags)
136 3b0f3d61 2020-01-22 neels {
137 3b0f3d61 2020-01-22 neels 	char *str1, *str2;
138 c6eecea3 2020-07-26 stsp 	int fd1, fd2;
139 3b0f3d61 2020-01-22 neels 	struct stat st1, st2;
140 3b0f3d61 2020-01-22 neels 	struct diff_input_info info = {
141 3b0f3d61 2020-01-22 neels 		.left_path = file1,
142 3b0f3d61 2020-01-22 neels 		.right_path = file2,
143 3b0f3d61 2020-01-22 neels 	};
144 f8cbb8fe 2020-05-05 neels 	struct diff_result *result;
145 3e6cba3a 2020-08-13 stsp 	int rc;
146 0d27172a 2020-05-06 neels 	const struct diff_config *cfg;
147 0d27172a 2020-05-06 neels 	
148 0d27172a 2020-05-06 neels 	cfg = do_patience ? &diff_config_patience : &diff_config;
149 3b0f3d61 2020-01-22 neels 
150 c6eecea3 2020-07-26 stsp 	fd1 = openfile(file1, &str1, &st1);
151 c6eecea3 2020-07-26 stsp 	fd2 = openfile(file2, &str2, &st2);
152 3b0f3d61 2020-01-22 neels 
153 c6eecea3 2020-07-26 stsp 	result = diff_main(cfg, fd1, str1, st1.st_size, fd2, str2, st2.st_size);
154 f8cbb8fe 2020-05-05 neels #if 0
155 f8cbb8fe 2020-05-05 neels 	rc = diff_output_plain(stdout, &info, result);
156 f8cbb8fe 2020-05-05 neels #else
157 f8cbb8fe 2020-05-05 neels 	rc = diff_output_unidiff(stdout, &info, result, 3);
158 f8cbb8fe 2020-05-05 neels #endif
159 f8cbb8fe 2020-05-05 neels 	diff_result_free(result);
160 3b0f3d61 2020-01-22 neels 
161 c6eecea3 2020-07-26 stsp 	if (str1)
162 c6eecea3 2020-07-26 stsp 		munmap(str1, st1.st_size);
163 c6eecea3 2020-07-26 stsp 	if (str2)
164 c6eecea3 2020-07-26 stsp 		munmap(str2, st2.st_size);
165 c6eecea3 2020-07-26 stsp 	close(fd1);
166 c6eecea3 2020-07-26 stsp 	close(fd2);
167 3b0f3d61 2020-01-22 neels 
168 f8cbb8fe 2020-05-05 neels 	return rc;
169 3b0f3d61 2020-01-22 neels }
170 3b0f3d61 2020-01-22 neels 
171 c6eecea3 2020-07-26 stsp int
172 c6eecea3 2020-07-26 stsp openfile(const char *path, char **p, struct stat *st)
173 3b0f3d61 2020-01-22 neels {
174 3b0f3d61 2020-01-22 neels 	int			 fd;
175 3b0f3d61 2020-01-22 neels 
176 3b0f3d61 2020-01-22 neels 	fd = open(path, O_RDONLY);
177 3b0f3d61 2020-01-22 neels 	if (fd == -1)
178 3b0f3d61 2020-01-22 neels 		err(2, "%s", path);
179 3b0f3d61 2020-01-22 neels 
180 3b0f3d61 2020-01-22 neels 	if (fstat(fd, st) == -1)
181 3b0f3d61 2020-01-22 neels 		err(2, "%s", path);
182 3b0f3d61 2020-01-22 neels 
183 c6eecea3 2020-07-26 stsp #ifndef DIFF_NO_MMAP
184 c6eecea3 2020-07-26 stsp 	*p = mmap(NULL, st->st_size, PROT_READ, MAP_PRIVATE, fd, 0);
185 c6eecea3 2020-07-26 stsp 	if (*p == MAP_FAILED)
186 c6eecea3 2020-07-26 stsp #endif
187 c6eecea3 2020-07-26 stsp 		*p = NULL; /* fall back on file I/O */
188 3b0f3d61 2020-01-22 neels 
189 c6eecea3 2020-07-26 stsp 	return fd;
190 3b0f3d61 2020-01-22 neels }