1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/stat.h>
18 
19 #include <string.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <fcntl.h>
23 #include <errno.h>
24 #include <unistd.h>
25 
26 #include "got_error.h"
27 #include "got_repository.h"
28 #include "got_refs.h"
29 #include "got_worktree.h"
30 
31 #include "got_worktree_priv.h"
32 #include "got_path_priv.h"
33 
34 static const struct got_error *
35 create_meta_file(const char *gotpath, const char *name, const char *content)
36 {
37 	const struct got_error *err = NULL;
38 	char *path;
39 	int fd = -1;
40 	char buf[4];
41 	ssize_t n;
42 
43 	if (asprintf(&path, "%s/%s", gotpath, name) == -1) {
44 		err = got_error(GOT_ERR_NO_MEM);
45 		path = NULL;
46 		goto done;
47 	}
48 
49 	fd = open(path, O_RDWR | O_CREAT | O_EXCL | O_EXLOCK | O_NOFOLLOW,
50 	    GOT_DEFAULT_FILE_MODE);
51 	if (fd == -1) {
52 		err = got_error_from_errno();
53 		goto done;
54 	}
55 
56 	/* The file should be empty. */
57 	n = read(fd, buf, sizeof(buf));
58 	if (n != 0) {
59 		err = (n == -1 ? got_error_from_errno() :
60 		    got_error(GOT_ERR_WORKTREE_EXISTS));
61 		goto done;
62 	}
63 
64 	if (content) {
65 		int len = dprintf(fd, "%s\n", content);
66 		if (len != strlen(content) + 1) {
67 			err = got_error_from_errno();
68 			goto done;
69 		}
70 	}
71 
72 done:
73 	if (fd != -1 && close(fd) == -1 && err == NULL)
74 		err = got_error_from_errno();
75 	free(path);
76 	return err;
77 }
78 
79 static const struct got_error *
80 read_meta_file(char **content, const char *gotpath, const char *name)
81 {
82 	const struct got_error *err = NULL;
83 	char *path;
84 	int fd = -1;
85 	ssize_t n;
86 	struct stat sb;
87 
88 	*content = NULL;
89 
90 	if (asprintf(&path, "%s/%s", gotpath, name) == -1) {
91 		err = got_error(GOT_ERR_NO_MEM);
92 		path = NULL;
93 		goto done;
94 	}
95 
96 	fd = open(path, O_RDONLY | O_EXCL | O_EXLOCK | O_NOFOLLOW);
97 	if (fd == -1) {
98 		err = got_error_from_errno();
99 		goto done;
100 	}
101 
102 	stat(path, &sb);
103 	*content = calloc(1, sb.st_size);
104 	if (*content == NULL) {
105 		err = got_error(GOT_ERR_NO_MEM);
106 		goto done;
107 	}
108 
109 	n = read(fd, *content, sb.st_size);
110 	if (n != sb.st_size) {
111 		err = got_error_from_errno();
112 		goto done;
113 	}
114 	if ((*content)[sb.st_size - 1] != '\n') {
115 		err = got_error(GOT_ERR_WORKTREE_META);
116 		goto done;
117 	}
118 	(*content)[sb.st_size - 1] = '\0';
119 
120 done:
121 	if (fd != -1 && close(fd) == -1 && err == NULL)
122 		err = got_error_from_errno();
123 	free(path);
124 	if (err) {
125 		free(*content);
126 		*content = NULL;
127 	}
128 	return err;
129 }
130 
131 const struct got_error *
132 got_worktree_init(const char *path, struct got_reference *head_ref,
133     const char *prefix, struct got_repository *repo)
134 {
135 	const struct got_error *err = NULL;
136 	char *gotpath = NULL;
137 	char *refstr = NULL;
138 	char *path_repos = NULL;
139 	char *formatstr = NULL;
140 
141 	if (!got_path_is_absolute(prefix))
142 		return got_error(GOT_ERR_BAD_PATH);
143 
144 	/* Create top-level directory (may already exist). */
145 	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
146 		err = got_error_from_errno();
147 		goto done;
148 	}
149 
150 	/* Create .got directory (may already exist). */
151 	if (asprintf(&gotpath, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
152 		err = got_error(GOT_ERR_NO_MEM);
153 		goto done;
154 	}
155 	if (mkdir(gotpath, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
156 		err = got_error_from_errno();
157 		goto done;
158 	}
159 
160 	/* Create an empty file index. */
161 	err = create_meta_file(gotpath, GOT_WORKTREE_FILE_INDEX, NULL);
162 	if (err)
163 		goto done;
164 
165 	/* Write the HEAD reference. */
166 	refstr = got_ref_to_str(head_ref);
167 	if (refstr == NULL) {
168 		err = got_error(GOT_ERR_NO_MEM);
169 		goto done;
170 	}
171 	err = create_meta_file(gotpath, GOT_REF_HEAD, refstr);
172 	if (err)
173 		goto done;
174 
175 	/* Store path to repository. */
176 	path_repos = got_repo_get_path(repo);
177 	if (path_repos == NULL) {
178 		err = got_error(GOT_ERR_NO_MEM);
179 		goto done;
180 	}
181 	err = create_meta_file(gotpath, GOT_WORKTREE_REPOSITORY, path_repos);
182 	if (err)
183 		goto done;
184 
185 	/* Store in-repository path prefix. */
186 	err = create_meta_file(gotpath, GOT_WORKTREE_PATH_PREFIX, prefix);
187 	if (err)
188 		goto done;
189 
190 	/* Stamp work tree with format file. */
191 	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
192 		err = got_error(GOT_ERR_NO_MEM);
193 		goto done;
194 	}
195 	err = create_meta_file(gotpath, GOT_WORKTREE_FORMAT, formatstr);
196 	if (err)
197 		goto done;
198 
199 done:
200 	free(gotpath);
201 	free(formatstr);
202 	free(refstr);
203 	free(path_repos);
204 	return err;
205 }
206 
207 const struct got_error *
208 got_worktree_open(struct got_worktree **worktree, const char *path)
209 {
210 	return NULL;
211 }
212 
213 void
214 got_worktree_close(struct got_worktree *worktree)
215 {
216 }
217 
218 char *
219 got_worktree_get_repo_path(struct got_worktree *worktree)
220 {
221 	return strdup(worktree->path_repo);
222 }
223 
224 struct got_reference *
225 got_worktree_get_head(struct got_worktree *worktree)
226 {
227 	return NULL;
228 }
229 
230 const struct got_error *
231 got_worktree_change_head(struct got_worktree *worktree, struct got_reference *head,
232     struct got_repository *repo)
233 {
234 	return NULL;
235 }
236 
237 const struct got_error *
238 got_worktree_checkout_files(struct got_worktree *worktree,
239     struct got_repository *repo)
240 {
241 	return NULL;
242 }