sequencer: lib'ify fast_forward_to()
[git] / worktree.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "strbuf.h"
4 #include "worktree.h"
5 #include "dir.h"
6 #include "wt-status.h"
7
8 void free_worktrees(struct worktree **worktrees)
9 {
10         int i = 0;
11
12         for (i = 0; worktrees[i]; i++) {
13                 free(worktrees[i]->path);
14                 free(worktrees[i]->id);
15                 free(worktrees[i]->head_ref);
16                 free(worktrees[i]->lock_reason);
17                 free(worktrees[i]);
18         }
19         free (worktrees);
20 }
21
22 /*
23  * read 'path_to_ref' into 'ref'.  Also if is_detached is not NULL,
24  * set is_detached to 1 (0) if the ref is detached (is not detached).
25  *
26  * $GIT_COMMON_DIR/$symref (e.g. HEAD) is practically outside $GIT_DIR so
27  * for linked worktrees, `resolve_ref_unsafe()` won't work (it uses
28  * git_path). Parse the ref ourselves.
29  *
30  * return -1 if the ref is not a proper ref, 0 otherwise (success)
31  */
32 static int parse_ref(char *path_to_ref, struct strbuf *ref, int *is_detached)
33 {
34         if (is_detached)
35                 *is_detached = 0;
36         if (!strbuf_readlink(ref, path_to_ref, 0)) {
37                 /* HEAD is symbolic link */
38                 if (!starts_with(ref->buf, "refs/") ||
39                                 check_refname_format(ref->buf, 0))
40                         return -1;
41         } else if (strbuf_read_file(ref, path_to_ref, 0) >= 0) {
42                 /* textual symref or detached */
43                 if (!starts_with(ref->buf, "ref:")) {
44                         if (is_detached)
45                                 *is_detached = 1;
46                 } else {
47                         strbuf_remove(ref, 0, strlen("ref:"));
48                         strbuf_trim(ref);
49                         if (check_refname_format(ref->buf, 0))
50                                 return -1;
51                 }
52         } else
53                 return -1;
54         return 0;
55 }
56
57 /**
58  * Add the head_sha1 and head_ref (if not detached) to the given worktree
59  */
60 static void add_head_info(struct strbuf *head_ref, struct worktree *worktree)
61 {
62         if (head_ref->len) {
63                 if (worktree->is_detached) {
64                         get_sha1_hex(head_ref->buf, worktree->head_sha1);
65                 } else {
66                         resolve_ref_unsafe(head_ref->buf, 0, worktree->head_sha1, NULL);
67                         worktree->head_ref = strbuf_detach(head_ref, NULL);
68                 }
69         }
70 }
71
72 /**
73  * get the main worktree
74  */
75 static struct worktree *get_main_worktree(void)
76 {
77         struct worktree *worktree = NULL;
78         struct strbuf path = STRBUF_INIT;
79         struct strbuf worktree_path = STRBUF_INIT;
80         struct strbuf head_ref = STRBUF_INIT;
81         int is_bare = 0;
82         int is_detached = 0;
83
84         strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
85         is_bare = !strbuf_strip_suffix(&worktree_path, "/.git");
86         if (is_bare)
87                 strbuf_strip_suffix(&worktree_path, "/.");
88
89         strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
90
91         if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
92                 goto done;
93
94         worktree = xmalloc(sizeof(struct worktree));
95         worktree->path = strbuf_detach(&worktree_path, NULL);
96         worktree->id = NULL;
97         worktree->is_bare = is_bare;
98         worktree->head_ref = NULL;
99         worktree->is_detached = is_detached;
100         worktree->is_current = 0;
101         add_head_info(&head_ref, worktree);
102         worktree->lock_reason = NULL;
103         worktree->lock_reason_valid = 0;
104
105 done:
106         strbuf_release(&path);
107         strbuf_release(&worktree_path);
108         strbuf_release(&head_ref);
109         return worktree;
110 }
111
112 static struct worktree *get_linked_worktree(const char *id)
113 {
114         struct worktree *worktree = NULL;
115         struct strbuf path = STRBUF_INIT;
116         struct strbuf worktree_path = STRBUF_INIT;
117         struct strbuf head_ref = STRBUF_INIT;
118         int is_detached = 0;
119
120         if (!id)
121                 die("Missing linked worktree name");
122
123         strbuf_git_common_path(&path, "worktrees/%s/gitdir", id);
124         if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
125                 /* invalid gitdir file */
126                 goto done;
127
128         strbuf_rtrim(&worktree_path);
129         if (!strbuf_strip_suffix(&worktree_path, "/.git")) {
130                 strbuf_reset(&worktree_path);
131                 strbuf_add_absolute_path(&worktree_path, ".");
132                 strbuf_strip_suffix(&worktree_path, "/.");
133         }
134
135         strbuf_reset(&path);
136         strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
137
138         if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
139                 goto done;
140
141         worktree = xmalloc(sizeof(struct worktree));
142         worktree->path = strbuf_detach(&worktree_path, NULL);
143         worktree->id = xstrdup(id);
144         worktree->is_bare = 0;
145         worktree->head_ref = NULL;
146         worktree->is_detached = is_detached;
147         worktree->is_current = 0;
148         add_head_info(&head_ref, worktree);
149         worktree->lock_reason = NULL;
150         worktree->lock_reason_valid = 0;
151
152 done:
153         strbuf_release(&path);
154         strbuf_release(&worktree_path);
155         strbuf_release(&head_ref);
156         return worktree;
157 }
158
159 static void mark_current_worktree(struct worktree **worktrees)
160 {
161         char *git_dir = xstrdup(absolute_path(get_git_dir()));
162         int i;
163
164         for (i = 0; worktrees[i]; i++) {
165                 struct worktree *wt = worktrees[i];
166                 const char *wt_git_dir = get_worktree_git_dir(wt);
167
168                 if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
169                         wt->is_current = 1;
170                         break;
171                 }
172         }
173         free(git_dir);
174 }
175
176 struct worktree **get_worktrees(void)
177 {
178         struct worktree **list = NULL;
179         struct strbuf path = STRBUF_INIT;
180         DIR *dir;
181         struct dirent *d;
182         int counter = 0, alloc = 2;
183
184         list = xmalloc(alloc * sizeof(struct worktree *));
185
186         if ((list[counter] = get_main_worktree()))
187                 counter++;
188
189         strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
190         dir = opendir(path.buf);
191         strbuf_release(&path);
192         if (dir) {
193                 while ((d = readdir(dir)) != NULL) {
194                         struct worktree *linked = NULL;
195                         if (is_dot_or_dotdot(d->d_name))
196                                 continue;
197
198                         if ((linked = get_linked_worktree(d->d_name))) {
199                                 ALLOC_GROW(list, counter + 1, alloc);
200                                 list[counter++] = linked;
201                         }
202                 }
203                 closedir(dir);
204         }
205         ALLOC_GROW(list, counter + 1, alloc);
206         list[counter] = NULL;
207
208         mark_current_worktree(list);
209         return list;
210 }
211
212 const char *get_worktree_git_dir(const struct worktree *wt)
213 {
214         if (!wt)
215                 return get_git_dir();
216         else if (!wt->id)
217                 return get_git_common_dir();
218         else
219                 return git_common_path("worktrees/%s", wt->id);
220 }
221
222 static struct worktree *find_worktree_by_suffix(struct worktree **list,
223                                                 const char *suffix)
224 {
225         struct worktree *found = NULL;
226         int nr_found = 0, suffixlen;
227
228         suffixlen = strlen(suffix);
229         if (!suffixlen)
230                 return NULL;
231
232         for (; *list && nr_found < 2; list++) {
233                 const char      *path    = (*list)->path;
234                 int              pathlen = strlen(path);
235                 int              start   = pathlen - suffixlen;
236
237                 /* suffix must start at directory boundary */
238                 if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
239                     !fspathcmp(suffix, path + start)) {
240                         found = *list;
241                         nr_found++;
242                 }
243         }
244         return nr_found == 1 ? found : NULL;
245 }
246
247 struct worktree *find_worktree(struct worktree **list,
248                                const char *prefix,
249                                const char *arg)
250 {
251         struct worktree *wt;
252         char *path;
253
254         if ((wt = find_worktree_by_suffix(list, arg)))
255                 return wt;
256
257         arg = prefix_filename(prefix, strlen(prefix), arg);
258         path = xstrdup(real_path(arg));
259         for (; *list; list++)
260                 if (!fspathcmp(path, real_path((*list)->path)))
261                         break;
262         free(path);
263         return *list;
264 }
265
266 int is_main_worktree(const struct worktree *wt)
267 {
268         return !wt->id;
269 }
270
271 const char *is_worktree_locked(struct worktree *wt)
272 {
273         assert(!is_main_worktree(wt));
274
275         if (!wt->lock_reason_valid) {
276                 struct strbuf path = STRBUF_INIT;
277
278                 strbuf_addstr(&path, worktree_git_path(wt, "locked"));
279                 if (file_exists(path.buf)) {
280                         struct strbuf lock_reason = STRBUF_INIT;
281                         if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
282                                 die_errno(_("failed to read '%s'"), path.buf);
283                         strbuf_trim(&lock_reason);
284                         wt->lock_reason = strbuf_detach(&lock_reason, NULL);
285                 } else
286                         wt->lock_reason = NULL;
287                 wt->lock_reason_valid = 1;
288                 strbuf_release(&path);
289         }
290
291         return wt->lock_reason;
292 }
293
294 int is_worktree_being_rebased(const struct worktree *wt,
295                               const char *target)
296 {
297         struct wt_status_state state;
298         int found_rebase;
299
300         memset(&state, 0, sizeof(state));
301         found_rebase = wt_status_check_rebase(wt, &state) &&
302                 ((state.rebase_in_progress ||
303                   state.rebase_interactive_in_progress) &&
304                  state.branch &&
305                  starts_with(target, "refs/heads/") &&
306                  !strcmp(state.branch, target + strlen("refs/heads/")));
307         free(state.branch);
308         free(state.onto);
309         return found_rebase;
310 }
311
312 int is_worktree_being_bisected(const struct worktree *wt,
313                                const char *target)
314 {
315         struct wt_status_state state;
316         int found_rebase;
317
318         memset(&state, 0, sizeof(state));
319         found_rebase = wt_status_check_bisect(wt, &state) &&
320                 state.branch &&
321                 starts_with(target, "refs/heads/") &&
322                 !strcmp(state.branch, target + strlen("refs/heads/"));
323         free(state.branch);
324         return found_rebase;
325 }
326
327 /*
328  * note: this function should be able to detect shared symref even if
329  * HEAD is temporarily detached (e.g. in the middle of rebase or
330  * bisect). New commands that do similar things should update this
331  * function as well.
332  */
333 const struct worktree *find_shared_symref(const char *symref,
334                                           const char *target)
335 {
336         const struct worktree *existing = NULL;
337         struct strbuf path = STRBUF_INIT;
338         struct strbuf sb = STRBUF_INIT;
339         static struct worktree **worktrees;
340         int i = 0;
341
342         if (worktrees)
343                 free_worktrees(worktrees);
344         worktrees = get_worktrees();
345
346         for (i = 0; worktrees[i]; i++) {
347                 struct worktree *wt = worktrees[i];
348
349                 if (wt->is_detached && !strcmp(symref, "HEAD")) {
350                         if (is_worktree_being_rebased(wt, target)) {
351                                 existing = wt;
352                                 break;
353                         }
354                         if (is_worktree_being_bisected(wt, target)) {
355                                 existing = wt;
356                                 break;
357                         }
358                 }
359
360                 strbuf_reset(&path);
361                 strbuf_reset(&sb);
362                 strbuf_addf(&path, "%s/%s",
363                             get_worktree_git_dir(wt),
364                             symref);
365
366                 if (parse_ref(path.buf, &sb, NULL)) {
367                         continue;
368                 }
369
370                 if (!strcmp(sb.buf, target)) {
371                         existing = wt;
372                         break;
373                 }
374         }
375
376         strbuf_release(&path);
377         strbuf_release(&sb);
378
379         return existing;
380 }