1 3b0f3d61 2020-01-22 neels /* Commandline diff utility to test diff implementations. */
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>
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.
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.
19 3b0f3d61 2020-01-22 neels #include <sys/mman.h>
20 3b0f3d61 2020-01-22 neels #include <sys/stat.h>
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>
29 8ad022d2 2020-05-05 neels #include <diff/diff_main.h>
30 8ad022d2 2020-05-05 neels #include <diff/diff_output.h>
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
36 3b0f3d61 2020-01-22 neels static const char *getprogname()
38 3b0f3d61 2020-01-22 neels return "diff";
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 *);
46 3b0f3d61 2020-01-22 neels __dead void
47 3b0f3d61 2020-01-22 neels usage(void)
49 760fe30e 2020-05-05 neels fprintf(stderr,
50 760fe30e 2020-05-05 neels "usage: %s [-p] file1 file2\n"
52 760fe30e 2020-05-05 neels " -p Use Patience Diff (slower but often nicer)\n"
53 760fe30e 2020-05-05 neels , getprogname());
57 760fe30e 2020-05-05 neels static bool do_patience = false;
60 3b0f3d61 2020-01-22 neels main(int argc, char *argv[])
64 760fe30e 2020-05-05 neels while ((ch = getopt(argc, argv, "p")) != -1) {
65 3b0f3d61 2020-01-22 neels switch (ch) {
67 760fe30e 2020-05-05 neels do_patience = true;
74 3b0f3d61 2020-01-22 neels argc -= optind;
75 3b0f3d61 2020-01-22 neels argv += optind;
77 3b0f3d61 2020-01-22 neels if (argc != 2)
80 3b0f3d61 2020-01-22 neels return diffreg(argv[0], argv[1], 0);
83 760fe30e 2020-05-05 neels const struct diff_algo_config myers_then_patience, myers_then_myers_divide, patience, myers_divide;
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,
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,
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.
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).
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,
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,
120 3b0f3d61 2020-01-22 neels diffreg(char *file1, char *file2, int flags)
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,
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;
132 3b0f3d61 2020-01-22 neels str1 = mmapfile(file1, &st1);
133 3b0f3d61 2020-01-22 neels str2 = mmapfile(file2, &st2);
135 760fe30e 2020-05-05 neels result = diff_main(cfg, str1, st1.st_size, str2, st2.st_size);
137 f8cbb8fe 2020-05-05 neels rc = diff_output_plain(stdout, &info, result);
139 f8cbb8fe 2020-05-05 neels rc = diff_output_unidiff(stdout, &info, result, 3);
141 f8cbb8fe 2020-05-05 neels diff_result_free(result);
143 3b0f3d61 2020-01-22 neels munmap(str1, st1.st_size);
144 3b0f3d61 2020-01-22 neels munmap(str2, st2.st_size);
146 f8cbb8fe 2020-05-05 neels return rc;
150 3b0f3d61 2020-01-22 neels mmapfile(const char *path, struct stat *st)
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);
159 3b0f3d61 2020-01-22 neels if (fstat(fd, st) == -1)
160 3b0f3d61 2020-01-22 neels err(2, "%s", path);
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);
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");
169 3b0f3d61 2020-01-22 neels close(fd);