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 760fe30e 2020-05-05 neels const struct diff_algo_config myers_then_patience, myers_then_myers_divide, patience, myers_divide;
 84 3b0f3d61 2020-01-22 neels 
 85 760fe30e 2020-05-05 neels const struct diff_algo_config myers_then_patience = (struct diff_algo_config){
 86 3b0f3d61 2020-01-22 neels 	.impl = diff_algo_myers,
 87 9e668157 2020-01-27 neels 	.permitted_state_size = 1024 * 1024 * sizeof(int),
 88 3b0f3d61 2020-01-22 neels 	.fallback_algo = &patience,
 89 3b0f3d61 2020-01-22 neels };
 90 3b0f3d61 2020-01-22 neels 
 91 760fe30e 2020-05-05 neels const struct diff_algo_config myers_then_myers_divide = (struct diff_algo_config){
 92 760fe30e 2020-05-05 neels 	.impl = diff_algo_myers,
 93 760fe30e 2020-05-05 neels 	.permitted_state_size = 1024 * 1024 * sizeof(int),
 94 760fe30e 2020-05-05 neels 	.fallback_algo = &myers_divide,
 95 760fe30e 2020-05-05 neels };
 96 760fe30e 2020-05-05 neels 
 97 3b0f3d61 2020-01-22 neels const struct diff_algo_config patience = (struct diff_algo_config){
 98 3b0f3d61 2020-01-22 neels 	.impl = diff_algo_patience,
 99 3b0f3d61 2020-01-22 neels 	.inner_algo = &patience,	// After subdivision, do Patience again.
100 760fe30e 2020-05-05 neels 	.fallback_algo = &myers_then_myers_divide, // If subdivision failed, do Myers Divide et Impera.
101 3b0f3d61 2020-01-22 neels };
102 3b0f3d61 2020-01-22 neels 
103 3b0f3d61 2020-01-22 neels const struct diff_algo_config myers_divide = (struct diff_algo_config){
104 3b0f3d61 2020-01-22 neels 	.impl = diff_algo_myers_divide,
105 760fe30e 2020-05-05 neels 	.inner_algo = &myers_then_myers_divide,	// When division succeeded, start from the top.
106 760fe30e 2020-05-05 neels 	// (fallback_algo = NULL implies diff_algo_none).
107 3b0f3d61 2020-01-22 neels };
108 3b0f3d61 2020-01-22 neels 
109 3b0f3d61 2020-01-22 neels const struct diff_config diff_config = {
110 3b0f3d61 2020-01-22 neels 	.atomize_func = diff_atomize_text_by_line,
111 760fe30e 2020-05-05 neels 	.algo = &myers_then_myers_divide,
112 3b0f3d61 2020-01-22 neels };
113 3b0f3d61 2020-01-22 neels 
114 760fe30e 2020-05-05 neels const struct diff_config diff_config_patience = {
115 760fe30e 2020-05-05 neels 	.atomize_func = diff_atomize_text_by_line,
116 760fe30e 2020-05-05 neels 	.algo = &myers_then_patience,
117 760fe30e 2020-05-05 neels };
118 760fe30e 2020-05-05 neels 
119 3b0f3d61 2020-01-22 neels int
120 3b0f3d61 2020-01-22 neels diffreg(char *file1, char *file2, int flags)
121 3b0f3d61 2020-01-22 neels {
122 3b0f3d61 2020-01-22 neels 	char *str1, *str2;
123 3b0f3d61 2020-01-22 neels 	struct stat st1, st2;
124 3b0f3d61 2020-01-22 neels 	struct diff_input_info info = {
125 3b0f3d61 2020-01-22 neels 		.left_path = file1,
126 3b0f3d61 2020-01-22 neels 		.right_path = file2,
127 3b0f3d61 2020-01-22 neels 	};
128 f8cbb8fe 2020-05-05 neels 	struct diff_result *result;
129 f8cbb8fe 2020-05-05 neels 	enum diff_rc rc;
130 760fe30e 2020-05-05 neels 	const struct diff_config *cfg = do_patience ? &diff_config_patience : &diff_config;
131 3b0f3d61 2020-01-22 neels 
132 3b0f3d61 2020-01-22 neels 	str1 = mmapfile(file1, &st1);
133 3b0f3d61 2020-01-22 neels 	str2 = mmapfile(file2, &st2);
134 3b0f3d61 2020-01-22 neels 
135 760fe30e 2020-05-05 neels 	result = diff_main(cfg, str1, st1.st_size, str2, st2.st_size);
136 f8cbb8fe 2020-05-05 neels #if 0
137 f8cbb8fe 2020-05-05 neels 	rc = diff_output_plain(stdout, &info, result);
138 f8cbb8fe 2020-05-05 neels #else
139 f8cbb8fe 2020-05-05 neels 	rc = diff_output_unidiff(stdout, &info, result, 3);
140 f8cbb8fe 2020-05-05 neels #endif
141 f8cbb8fe 2020-05-05 neels 	diff_result_free(result);
142 3b0f3d61 2020-01-22 neels 
143 3b0f3d61 2020-01-22 neels 	munmap(str1, st1.st_size);
144 3b0f3d61 2020-01-22 neels 	munmap(str2, st2.st_size);
145 3b0f3d61 2020-01-22 neels 
146 f8cbb8fe 2020-05-05 neels 	return rc;
147 3b0f3d61 2020-01-22 neels }
148 3b0f3d61 2020-01-22 neels 
149 3b0f3d61 2020-01-22 neels char *
150 3b0f3d61 2020-01-22 neels mmapfile(const char *path, struct stat *st)
151 3b0f3d61 2020-01-22 neels {
152 3b0f3d61 2020-01-22 neels 	int			 fd;
153 3b0f3d61 2020-01-22 neels 	char			*p;
154 3b0f3d61 2020-01-22 neels 
155 3b0f3d61 2020-01-22 neels 	fd = open(path, O_RDONLY);
156 3b0f3d61 2020-01-22 neels 	if (fd == -1)
157 3b0f3d61 2020-01-22 neels 		err(2, "%s", path);
158 3b0f3d61 2020-01-22 neels 
159 3b0f3d61 2020-01-22 neels 	if (fstat(fd, st) == -1)
160 3b0f3d61 2020-01-22 neels 		err(2, "%s", path);
161 3b0f3d61 2020-01-22 neels 
162 3b0f3d61 2020-01-22 neels 	if ((uintmax_t)st->st_size > SIZE_MAX)
163 3b0f3d61 2020-01-22 neels 		errx(2, "%s: file too big to fit memory", path);
164 3b0f3d61 2020-01-22 neels 
165 3b0f3d61 2020-01-22 neels 	p = mmap(NULL, st->st_size, PROT_READ, MAP_PRIVATE, fd, 0);
166 3b0f3d61 2020-01-22 neels 	if (p == MAP_FAILED)
167 3b0f3d61 2020-01-22 neels 		err(2, "mmap");
168 3b0f3d61 2020-01-22 neels 
169 3b0f3d61 2020-01-22 neels 	close(fd);
170 3b0f3d61 2020-01-22 neels 
171 3b0f3d61 2020-01-22 neels 	return p;
172 3b0f3d61 2020-01-22 neels }