worktree.c: make find_shared_symref() return struct worktree *
[git] / worktree.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "strbuf.h"
4 #include "worktree.h"
5
6 void free_worktrees(struct worktree **worktrees)
7 {
8         int i = 0;
9
10         for (i = 0; worktrees[i]; i++) {
11                 free(worktrees[i]->path);
12                 free(worktrees[i]->id);
13                 free(worktrees[i]->head_ref);
14                 free(worktrees[i]);
15         }
16         free (worktrees);
17 }
18
19 /*
20  * read 'path_to_ref' into 'ref'.  Also if is_detached is not NULL,
21  * set is_detached to 1 (0) if the ref is detatched (is not detached).
22  *
23  * $GIT_COMMON_DIR/$symref (e.g. HEAD) is practically outside $GIT_DIR so
24  * for linked worktrees, `resolve_ref_unsafe()` won't work (it uses
25  * git_path). Parse the ref ourselves.
26  *
27  * return -1 if the ref is not a proper ref, 0 otherwise (success)
28  */
29 static int parse_ref(char *path_to_ref, struct strbuf *ref, int *is_detached)
30 {
31         if (is_detached)
32                 *is_detached = 0;
33         if (!strbuf_readlink(ref, path_to_ref, 0)) {
34                 /* HEAD is symbolic link */
35                 if (!starts_with(ref->buf, "refs/") ||
36                                 check_refname_format(ref->buf, 0))
37                         return -1;
38         } else if (strbuf_read_file(ref, path_to_ref, 0) >= 0) {
39                 /* textual symref or detached */
40                 if (!starts_with(ref->buf, "ref:")) {
41                         if (is_detached)
42                                 *is_detached = 1;
43                 } else {
44                         strbuf_remove(ref, 0, strlen("ref:"));
45                         strbuf_trim(ref);
46                         if (check_refname_format(ref->buf, 0))
47                                 return -1;
48                 }
49         } else
50                 return -1;
51         return 0;
52 }
53
54 /**
55  * Add the head_sha1 and head_ref (if not detached) to the given worktree
56  */
57 static void add_head_info(struct strbuf *head_ref, struct worktree *worktree)
58 {
59         if (head_ref->len) {
60                 if (worktree->is_detached) {
61                         get_sha1_hex(head_ref->buf, worktree->head_sha1);
62                 } else {
63                         resolve_ref_unsafe(head_ref->buf, 0, worktree->head_sha1, NULL);
64                         worktree->head_ref = strbuf_detach(head_ref, NULL);
65                 }
66         }
67 }
68
69 /**
70  * get the main worktree
71  */
72 static struct worktree *get_main_worktree(void)
73 {
74         struct worktree *worktree = NULL;
75         struct strbuf path = STRBUF_INIT;
76         struct strbuf worktree_path = STRBUF_INIT;
77         struct strbuf head_ref = STRBUF_INIT;
78         int is_bare = 0;
79         int is_detached = 0;
80
81         strbuf_addstr(&worktree_path, absolute_path(get_git_common_dir()));
82         is_bare = !strbuf_strip_suffix(&worktree_path, "/.git");
83         if (is_bare)
84                 strbuf_strip_suffix(&worktree_path, "/.");
85
86         strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
87
88         if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
89                 goto done;
90
91         worktree = xmalloc(sizeof(struct worktree));
92         worktree->path = strbuf_detach(&worktree_path, NULL);
93         worktree->id = NULL;
94         worktree->is_bare = is_bare;
95         worktree->head_ref = NULL;
96         worktree->is_detached = is_detached;
97         add_head_info(&head_ref, worktree);
98
99 done:
100         strbuf_release(&path);
101         strbuf_release(&worktree_path);
102         strbuf_release(&head_ref);
103         return worktree;
104 }
105
106 static struct worktree *get_linked_worktree(const char *id)
107 {
108         struct worktree *worktree = NULL;
109         struct strbuf path = STRBUF_INIT;
110         struct strbuf worktree_path = STRBUF_INIT;
111         struct strbuf head_ref = STRBUF_INIT;
112         int is_detached = 0;
113
114         if (!id)
115                 die("Missing linked worktree name");
116
117         strbuf_git_common_path(&path, "worktrees/%s/gitdir", id);
118         if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
119                 /* invalid gitdir file */
120                 goto done;
121
122         strbuf_rtrim(&worktree_path);
123         if (!strbuf_strip_suffix(&worktree_path, "/.git")) {
124                 strbuf_reset(&worktree_path);
125                 strbuf_addstr(&worktree_path, absolute_path("."));
126                 strbuf_strip_suffix(&worktree_path, "/.");
127         }
128
129         strbuf_reset(&path);
130         strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
131
132         if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
133                 goto done;
134
135         worktree = xmalloc(sizeof(struct worktree));
136         worktree->path = strbuf_detach(&worktree_path, NULL);
137         worktree->id = xstrdup(id);
138         worktree->is_bare = 0;
139         worktree->head_ref = NULL;
140         worktree->is_detached = is_detached;
141         add_head_info(&head_ref, worktree);
142
143 done:
144         strbuf_release(&path);
145         strbuf_release(&worktree_path);
146         strbuf_release(&head_ref);
147         return worktree;
148 }
149
150 struct worktree **get_worktrees(void)
151 {
152         struct worktree **list = NULL;
153         struct strbuf path = STRBUF_INIT;
154         DIR *dir;
155         struct dirent *d;
156         int counter = 0, alloc = 2;
157
158         list = xmalloc(alloc * sizeof(struct worktree *));
159
160         if ((list[counter] = get_main_worktree()))
161                 counter++;
162
163         strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
164         dir = opendir(path.buf);
165         strbuf_release(&path);
166         if (dir) {
167                 while ((d = readdir(dir)) != NULL) {
168                         struct worktree *linked = NULL;
169                         if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
170                                 continue;
171
172                         if ((linked = get_linked_worktree(d->d_name))) {
173                                 ALLOC_GROW(list, counter + 1, alloc);
174                                 list[counter++] = linked;
175                         }
176                 }
177                 closedir(dir);
178         }
179         ALLOC_GROW(list, counter + 1, alloc);
180         list[counter] = NULL;
181         return list;
182 }
183
184 const char *get_worktree_git_dir(const struct worktree *wt)
185 {
186         if (!wt)
187                 return get_git_dir();
188         else if (!wt->id)
189                 return get_git_common_dir();
190         else
191                 return git_common_path("worktrees/%s", wt->id);
192 }
193
194 const struct worktree *find_shared_symref(const char *symref,
195                                           const char *target)
196 {
197         const struct worktree *existing = NULL;
198         struct strbuf path = STRBUF_INIT;
199         struct strbuf sb = STRBUF_INIT;
200         static struct worktree **worktrees;
201         int i = 0;
202
203         if (worktrees)
204                 free_worktrees(worktrees);
205         worktrees = get_worktrees();
206
207         for (i = 0; worktrees[i]; i++) {
208                 strbuf_reset(&path);
209                 strbuf_reset(&sb);
210                 strbuf_addf(&path, "%s/%s",
211                             get_worktree_git_dir(worktrees[i]),
212                             symref);
213
214                 if (parse_ref(path.buf, &sb, NULL)) {
215                         continue;
216                 }
217
218                 if (!strcmp(sb.buf, target)) {
219                         existing = worktrees[i];
220                         break;
221                 }
222         }
223
224         strbuf_release(&path);
225         strbuf_release(&sb);
226
227         return existing;
228 }