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 3b0f3d61 2020-01-22 neels #include <unistd.h>
 28 3b0f3d61 2020-01-22 neels 
 29 8ad022d2 2020-05-05 neels #include <diff/diff_main.h>
 30 8ad022d2 2020-05-05 neels #include <diff/diff_output.h>
 31 8ad022d2 2020-05-05 neels 
 32 3b0f3d61 2020-01-22 neels #ifdef __linux__
 33 3b0f3d61 2020-01-22 neels /* stupid shims to compile and test on linux */
 34 3b0f3d61 2020-01-22 neels #define __dead
 35 3b0f3d61 2020-01-22 neels 
 36 3b0f3d61 2020-01-22 neels static const char *getprogname()
 37 3b0f3d61 2020-01-22 neels {
 38 3b0f3d61 2020-01-22 neels 	return "diff";
 39 3b0f3d61 2020-01-22 neels }
 40 3b0f3d61 2020-01-22 neels #endif
 41 3b0f3d61 2020-01-22 neels 
 42 3b0f3d61 2020-01-22 neels __dead void	 usage(void);
 43 3b0f3d61 2020-01-22 neels int		 diffreg(char *, char *, int);
 44 3b0f3d61 2020-01-22 neels char		*mmapfile(const char *, struct stat *);
 45 3b0f3d61 2020-01-22 neels 
 46 3b0f3d61 2020-01-22 neels __dead void
 47 3b0f3d61 2020-01-22 neels usage(void)
 48 3b0f3d61 2020-01-22 neels {
 49 760fe30e 2020-05-05 neels 	fprintf(stderr,
 50 760fe30e 2020-05-05 neels 		"usage: %s [-p] file1 file2\n"
 51 760fe30e 2020-05-05 neels 		"\n"
 52 760fe30e 2020-05-05 neels 		"  -p   Use Patience Diff (slower but often nicer)\n"
 53 760fe30e 2020-05-05 neels 		, getprogname());
 54 3b0f3d61 2020-01-22 neels 	exit(1);
 55 3b0f3d61 2020-01-22 neels }
 56 3b0f3d61 2020-01-22 neels 
 57 760fe30e 2020-05-05 neels static bool do_patience = false;
 58 760fe30e 2020-05-05 neels 
 59 3b0f3d61 2020-01-22 neels int
 60 3b0f3d61 2020-01-22 neels main(int argc, char *argv[])
 61 3b0f3d61 2020-01-22 neels {
 62 3b0f3d61 2020-01-22 neels 	int ch;
 63 3b0f3d61 2020-01-22 neels 
 64 760fe30e 2020-05-05 neels 	while ((ch = getopt(argc, argv, "p")) != -1) {
 65 3b0f3d61 2020-01-22 neels 		switch (ch) {
 66 760fe30e 2020-05-05 neels 		case 'p':
 67 760fe30e 2020-05-05 neels 			do_patience = true;
 68 760fe30e 2020-05-05 neels 			break;
 69 3b0f3d61 2020-01-22 neels 		default:
 70 3b0f3d61 2020-01-22 neels 			usage();
 71 3b0f3d61 2020-01-22 neels 		}
 72 3b0f3d61 2020-01-22 neels 	}
 73 3b0f3d61 2020-01-22 neels 
 74 3b0f3d61 2020-01-22 neels 	argc -= optind;
 75 3b0f3d61 2020-01-22 neels 	argv += optind;
 76 3b0f3d61 2020-01-22 neels 
 77 3b0f3d61 2020-01-22 neels 	if (argc != 2)
 78 3b0f3d61 2020-01-22 neels 		usage();
 79 3b0f3d61 2020-01-22 neels 
 80 3b0f3d61 2020-01-22 neels 	return diffreg(argv[0], argv[1], 0);
 81 3b0f3d61 2020-01-22 neels }
 82 3b0f3d61 2020-01-22 neels 
 83 0d27172a 2020-05-06 neels const struct diff_algo_config myers_then_patience;
 84 0d27172a 2020-05-06 neels const struct diff_algo_config myers_then_myers_divide;
 85 0d27172a 2020-05-06 neels const struct diff_algo_config patience;
 86 0d27172a 2020-05-06 neels const struct diff_algo_config myers_divide;
 87 3b0f3d61 2020-01-22 neels 
 88 760fe30e 2020-05-05 neels const struct diff_algo_config myers_then_patience = (struct diff_algo_config){
 89 3b0f3d61 2020-01-22 neels 	.impl = diff_algo_myers,
 90 9e668157 2020-01-27 neels 	.permitted_state_size = 1024 * 1024 * sizeof(int),
 91 3b0f3d61 2020-01-22 neels 	.fallback_algo = &patience,
 92 3b0f3d61 2020-01-22 neels };
 93 3b0f3d61 2020-01-22 neels 
 94 0d27172a 2020-05-06 neels const struct diff_algo_config myers_then_myers_divide =
 95 0d27172a 2020-05-06 neels 	(struct diff_algo_config){
 96 760fe30e 2020-05-05 neels 	.impl = diff_algo_myers,
 97 760fe30e 2020-05-05 neels 	.permitted_state_size = 1024 * 1024 * sizeof(int),
 98 760fe30e 2020-05-05 neels 	.fallback_algo = &myers_divide,
 99 760fe30e 2020-05-05 neels };
100 760fe30e 2020-05-05 neels 
101 3b0f3d61 2020-01-22 neels const struct diff_algo_config patience = (struct diff_algo_config){
102 3b0f3d61 2020-01-22 neels 	.impl = diff_algo_patience,
103 0d27172a 2020-05-06 neels 	/* After subdivision, do Patience again: */
104 0d27172a 2020-05-06 neels 	.inner_algo = &patience,
105 0d27172a 2020-05-06 neels 	/* If subdivision failed, do Myers Divide et Impera: */
106 0d27172a 2020-05-06 neels 	.fallback_algo = &myers_then_myers_divide,
107 3b0f3d61 2020-01-22 neels };
108 3b0f3d61 2020-01-22 neels 
109 3b0f3d61 2020-01-22 neels const struct diff_algo_config myers_divide = (struct diff_algo_config){
110 3b0f3d61 2020-01-22 neels 	.impl = diff_algo_myers_divide,
111 0d27172a 2020-05-06 neels 	/* When division succeeded, start from the top: */
112 0d27172a 2020-05-06 neels 	.inner_algo = &myers_then_myers_divide,
113 0d27172a 2020-05-06 neels 	/* (fallback_algo = NULL implies diff_algo_none). */
114 3b0f3d61 2020-01-22 neels };
115 3b0f3d61 2020-01-22 neels 
116 3b0f3d61 2020-01-22 neels const struct diff_config diff_config = {
117 3b0f3d61 2020-01-22 neels 	.atomize_func = diff_atomize_text_by_line,
118 760fe30e 2020-05-05 neels 	.algo = &myers_then_myers_divide,
119 3b0f3d61 2020-01-22 neels };
120 3b0f3d61 2020-01-22 neels 
121 760fe30e 2020-05-05 neels const struct diff_config diff_config_patience = {
122 760fe30e 2020-05-05 neels 	.atomize_func = diff_atomize_text_by_line,
123 760fe30e 2020-05-05 neels 	.algo = &myers_then_patience,
124 760fe30e 2020-05-05 neels };
125 760fe30e 2020-05-05 neels 
126 3b0f3d61 2020-01-22 neels int
127 3b0f3d61 2020-01-22 neels diffreg(char *file1, char *file2, int flags)
128 3b0f3d61 2020-01-22 neels {
129 3b0f3d61 2020-01-22 neels 	char *str1, *str2;
130 3b0f3d61 2020-01-22 neels 	struct stat st1, st2;
131 3b0f3d61 2020-01-22 neels 	struct diff_input_info info = {
132 3b0f3d61 2020-01-22 neels 		.left_path = file1,
133 3b0f3d61 2020-01-22 neels 		.right_path = file2,
134 3b0f3d61 2020-01-22 neels 	};
135 f8cbb8fe 2020-05-05 neels 	struct diff_result *result;
136 f8cbb8fe 2020-05-05 neels 	enum diff_rc rc;
137 0d27172a 2020-05-06 neels 	const struct diff_config *cfg;
138 0d27172a 2020-05-06 neels 	
139 0d27172a 2020-05-06 neels 	cfg = do_patience ? &diff_config_patience : &diff_config;
140 3b0f3d61 2020-01-22 neels 
141 3b0f3d61 2020-01-22 neels 	str1 = mmapfile(file1, &st1);
142 3b0f3d61 2020-01-22 neels 	str2 = mmapfile(file2, &st2);
143 3b0f3d61 2020-01-22 neels 
144 760fe30e 2020-05-05 neels 	result = diff_main(cfg, str1, st1.st_size, str2, st2.st_size);
145 f8cbb8fe 2020-05-05 neels #if 0
146 f8cbb8fe 2020-05-05 neels 	rc = diff_output_plain(stdout, &info, result);
147 f8cbb8fe 2020-05-05 neels #else
148 f8cbb8fe 2020-05-05 neels 	rc = diff_output_unidiff(stdout, &info, result, 3);
149 f8cbb8fe 2020-05-05 neels #endif
150 f8cbb8fe 2020-05-05 neels 	diff_result_free(result);
151 3b0f3d61 2020-01-22 neels 
152 3b0f3d61 2020-01-22 neels 	munmap(str1, st1.st_size);
153 3b0f3d61 2020-01-22 neels 	munmap(str2, st2.st_size);
154 3b0f3d61 2020-01-22 neels 
155 f8cbb8fe 2020-05-05 neels 	return rc;
156 3b0f3d61 2020-01-22 neels }
157 3b0f3d61 2020-01-22 neels 
158 3b0f3d61 2020-01-22 neels char *
159 3b0f3d61 2020-01-22 neels mmapfile(const char *path, struct stat *st)
160 3b0f3d61 2020-01-22 neels {
161 3b0f3d61 2020-01-22 neels 	int			 fd;
162 3b0f3d61 2020-01-22 neels 	char			*p;
163 3b0f3d61 2020-01-22 neels 
164 3b0f3d61 2020-01-22 neels 	fd = open(path, O_RDONLY);
165 3b0f3d61 2020-01-22 neels 	if (fd == -1)
166 3b0f3d61 2020-01-22 neels 		err(2, "%s", path);
167 3b0f3d61 2020-01-22 neels 
168 3b0f3d61 2020-01-22 neels 	if (fstat(fd, st) == -1)
169 3b0f3d61 2020-01-22 neels 		err(2, "%s", path);
170 3b0f3d61 2020-01-22 neels 
171 3b0f3d61 2020-01-22 neels 	if ((uintmax_t)st->st_size > SIZE_MAX)
172 3b0f3d61 2020-01-22 neels 		errx(2, "%s: file too big to fit memory", path);
173 3b0f3d61 2020-01-22 neels 
174 3b0f3d61 2020-01-22 neels 	p = mmap(NULL, st->st_size, PROT_READ, MAP_PRIVATE, fd, 0);
175 3b0f3d61 2020-01-22 neels 	if (p == MAP_FAILED)
176 3b0f3d61 2020-01-22 neels 		err(2, "mmap");
177 3b0f3d61 2020-01-22 neels 
178 3b0f3d61 2020-01-22 neels 	close(fd);
179 3b0f3d61 2020-01-22 neels 
180 3b0f3d61 2020-01-22 neels 	return p;
181 3b0f3d61 2020-01-22 neels }