Merge branch 'bc/reflog-fix' into js/reflog-delete
[git] / builtin-reflog.c
1 #include "cache.h"
2 #include "builtin.h"
3 #include "commit.h"
4 #include "refs.h"
5 #include "dir.h"
6 #include "tree-walk.h"
7 #include "diff.h"
8 #include "revision.h"
9 #include "reachable.h"
10
11 /*
12  * reflog expire
13  */
14
15 static const char reflog_expire_usage[] =
16 "git-reflog (show|expire) [--verbose] [--dry-run] [--stale-fix] [--expire=<time>] [--expire-unreachable=<time>] [--all] <refs>...";
17
18 static unsigned long default_reflog_expire;
19 static unsigned long default_reflog_expire_unreachable;
20
21 struct cmd_reflog_expire_cb {
22         struct rev_info revs;
23         int dry_run;
24         int stalefix;
25         int verbose;
26         unsigned long expire_total;
27         unsigned long expire_unreachable;
28         int recno;
29 };
30
31 struct expire_reflog_cb {
32         FILE *newlog;
33         const char *ref;
34         struct commit *ref_commit;
35         struct cmd_reflog_expire_cb *cmd;
36 };
37
38 struct collected_reflog {
39         unsigned char sha1[20];
40         char reflog[FLEX_ARRAY];
41 };
42 struct collect_reflog_cb {
43         struct collected_reflog **e;
44         int alloc;
45         int nr;
46 };
47
48 #define INCOMPLETE      (1u<<10)
49 #define STUDYING        (1u<<11)
50
51 static int tree_is_complete(const unsigned char *sha1)
52 {
53         struct tree_desc desc;
54         struct name_entry entry;
55         int complete;
56         struct tree *tree;
57
58         tree = lookup_tree(sha1);
59         if (!tree)
60                 return 0;
61         if (tree->object.flags & SEEN)
62                 return 1;
63         if (tree->object.flags & INCOMPLETE)
64                 return 0;
65
66         if (!tree->buffer) {
67                 enum object_type type;
68                 unsigned long size;
69                 void *data = read_sha1_file(sha1, &type, &size);
70                 if (!data) {
71                         tree->object.flags |= INCOMPLETE;
72                         return 0;
73                 }
74                 tree->buffer = data;
75                 tree->size = size;
76         }
77         init_tree_desc(&desc, tree->buffer, tree->size);
78         complete = 1;
79         while (tree_entry(&desc, &entry)) {
80                 if (!has_sha1_file(entry.sha1) ||
81                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
82                         tree->object.flags |= INCOMPLETE;
83                         complete = 0;
84                 }
85         }
86         free(tree->buffer);
87         tree->buffer = NULL;
88
89         if (complete)
90                 tree->object.flags |= SEEN;
91         return complete;
92 }
93
94 static int commit_is_complete(struct commit *commit)
95 {
96         struct object_array study;
97         struct object_array found;
98         int is_incomplete = 0;
99         int i;
100
101         /* early return */
102         if (commit->object.flags & SEEN)
103                 return 1;
104         if (commit->object.flags & INCOMPLETE)
105                 return 0;
106         /*
107          * Find all commits that are reachable and are not marked as
108          * SEEN.  Then make sure the trees and blobs contained are
109          * complete.  After that, mark these commits also as SEEN.
110          * If some of the objects that are needed to complete this
111          * commit are missing, mark this commit as INCOMPLETE.
112          */
113         memset(&study, 0, sizeof(study));
114         memset(&found, 0, sizeof(found));
115         add_object_array(&commit->object, NULL, &study);
116         add_object_array(&commit->object, NULL, &found);
117         commit->object.flags |= STUDYING;
118         while (study.nr) {
119                 struct commit *c;
120                 struct commit_list *parent;
121
122                 c = (struct commit *)study.objects[--study.nr].item;
123                 if (!c->object.parsed && !parse_object(c->object.sha1))
124                         c->object.flags |= INCOMPLETE;
125
126                 if (c->object.flags & INCOMPLETE) {
127                         is_incomplete = 1;
128                         break;
129                 }
130                 else if (c->object.flags & SEEN)
131                         continue;
132                 for (parent = c->parents; parent; parent = parent->next) {
133                         struct commit *p = parent->item;
134                         if (p->object.flags & STUDYING)
135                                 continue;
136                         p->object.flags |= STUDYING;
137                         add_object_array(&p->object, NULL, &study);
138                         add_object_array(&p->object, NULL, &found);
139                 }
140         }
141         if (!is_incomplete) {
142                 /*
143                  * make sure all commits in "found" array have all the
144                  * necessary objects.
145                  */
146                 for (i = 0; i < found.nr; i++) {
147                         struct commit *c =
148                                 (struct commit *)found.objects[i].item;
149                         if (!tree_is_complete(c->tree->object.sha1)) {
150                                 is_incomplete = 1;
151                                 c->object.flags |= INCOMPLETE;
152                         }
153                 }
154                 if (!is_incomplete) {
155                         /* mark all found commits as complete, iow SEEN */
156                         for (i = 0; i < found.nr; i++)
157                                 found.objects[i].item->flags |= SEEN;
158                 }
159         }
160         /* clear flags from the objects we traversed */
161         for (i = 0; i < found.nr; i++)
162                 found.objects[i].item->flags &= ~STUDYING;
163         if (is_incomplete)
164                 commit->object.flags |= INCOMPLETE;
165         else {
166                 /*
167                  * If we come here, we have (1) traversed the ancestry chain
168                  * from the "commit" until we reach SEEN commits (which are
169                  * known to be complete), and (2) made sure that the commits
170                  * encountered during the above traversal refer to trees that
171                  * are complete.  Which means that we know *all* the commits
172                  * we have seen during this process are complete.
173                  */
174                 for (i = 0; i < found.nr; i++)
175                         found.objects[i].item->flags |= SEEN;
176         }
177         /* free object arrays */
178         free(study.objects);
179         free(found.objects);
180         return !is_incomplete;
181 }
182
183 static int keep_entry(struct commit **it, unsigned char *sha1)
184 {
185         struct commit *commit;
186
187         if (is_null_sha1(sha1))
188                 return 1;
189         commit = lookup_commit_reference_gently(sha1, 1);
190         if (!commit)
191                 return 0;
192
193         /*
194          * Make sure everything in this commit exists.
195          *
196          * We have walked all the objects reachable from the refs
197          * and cache earlier.  The commits reachable by this commit
198          * must meet SEEN commits -- and then we should mark them as
199          * SEEN as well.
200          */
201         if (!commit_is_complete(commit))
202                 return 0;
203         *it = commit;
204         return 1;
205 }
206
207 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
208                 const char *email, unsigned long timestamp, int tz,
209                 const char *message, void *cb_data)
210 {
211         struct expire_reflog_cb *cb = cb_data;
212         struct commit *old, *new;
213
214         if (timestamp < cb->cmd->expire_total)
215                 goto prune;
216
217         old = new = NULL;
218         if (cb->cmd->stalefix &&
219             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
220                 goto prune;
221
222         if (timestamp < cb->cmd->expire_unreachable) {
223                 if (!cb->ref_commit)
224                         goto prune;
225                 if (!old && !is_null_sha1(osha1))
226                         old = lookup_commit_reference_gently(osha1, 1);
227                 if (!new && !is_null_sha1(nsha1))
228                         new = lookup_commit_reference_gently(nsha1, 1);
229                 if ((old && !in_merge_bases(old, &cb->ref_commit, 1)) ||
230                     (new && !in_merge_bases(new, &cb->ref_commit, 1)))
231                         goto prune;
232         }
233
234         if (cb->cmd->recno && --(cb->cmd->recno) == 0)
235                 goto prune;
236
237         if (cb->newlog) {
238                 char sign = (tz < 0) ? '-' : '+';
239                 int zone = (tz < 0) ? (-tz) : tz;
240                 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
241                         sha1_to_hex(osha1), sha1_to_hex(nsha1),
242                         email, timestamp, sign, zone,
243                         message);
244         }
245         if (cb->cmd->verbose)
246                 printf("keep %s", message);
247         return 0;
248  prune:
249         if (!cb->newlog || cb->cmd->verbose)
250                 printf("%sprune %s", cb->newlog ? "" : "would ", message);
251         return 0;
252 }
253
254 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
255 {
256         struct cmd_reflog_expire_cb *cmd = cb_data;
257         struct expire_reflog_cb cb;
258         struct ref_lock *lock;
259         char *log_file, *newlog_path = NULL;
260         int status = 0;
261
262         memset(&cb, 0, sizeof(cb));
263         /* we take the lock for the ref itself to prevent it from
264          * getting updated.
265          */
266         lock = lock_any_ref_for_update(ref, sha1, 0);
267         if (!lock)
268                 return error("cannot lock ref '%s'", ref);
269         log_file = xstrdup(git_path("logs/%s", ref));
270         if (!file_exists(log_file))
271                 goto finish;
272         if (!cmd->dry_run) {
273                 newlog_path = xstrdup(git_path("logs/%s.lock", ref));
274                 cb.newlog = fopen(newlog_path, "w");
275         }
276
277         cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
278         cb.ref = ref;
279         cb.cmd = cmd;
280         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
281  finish:
282         if (cb.newlog) {
283                 if (fclose(cb.newlog)) {
284                         status |= error("%s: %s", strerror(errno),
285                                         newlog_path);
286                         unlink(newlog_path);
287                 } else if (rename(newlog_path, log_file)) {
288                         status |= error("cannot rename %s to %s",
289                                         newlog_path, log_file);
290                         unlink(newlog_path);
291                 }
292         }
293         free(newlog_path);
294         free(log_file);
295         unlock_ref(lock);
296         return status;
297 }
298
299 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
300 {
301         struct collected_reflog *e;
302         struct collect_reflog_cb *cb = cb_data;
303         size_t namelen = strlen(ref);
304
305         e = xmalloc(sizeof(*e) + namelen + 1);
306         hashcpy(e->sha1, sha1);
307         memcpy(e->reflog, ref, namelen + 1);
308         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
309         cb->e[cb->nr++] = e;
310         return 0;
311 }
312
313 static int reflog_expire_config(const char *var, const char *value)
314 {
315         if (!strcmp(var, "gc.reflogexpire")) {
316                 if (!value)
317                         config_error_nonbool(var);
318                 default_reflog_expire = approxidate(value);
319                 return 0;
320         }
321         if (!strcmp(var, "gc.reflogexpireunreachable")) {
322                 if (!value)
323                         config_error_nonbool(var);
324                 default_reflog_expire_unreachable = approxidate(value);
325                 return 0;
326         }
327         return git_default_config(var, value);
328 }
329
330 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
331 {
332         struct cmd_reflog_expire_cb cb;
333         unsigned long now = time(NULL);
334         int i, status, do_all;
335
336         git_config(reflog_expire_config);
337
338         save_commit_buffer = 0;
339         do_all = status = 0;
340         memset(&cb, 0, sizeof(cb));
341
342         if (!default_reflog_expire_unreachable)
343                 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
344         if (!default_reflog_expire)
345                 default_reflog_expire = now - 90 * 24 * 3600;
346         cb.expire_total = default_reflog_expire;
347         cb.expire_unreachable = default_reflog_expire_unreachable;
348
349         /*
350          * We can trust the commits and objects reachable from refs
351          * even in older repository.  We cannot trust what's reachable
352          * from reflog if the repository was pruned with older git.
353          */
354
355         for (i = 1; i < argc; i++) {
356                 const char *arg = argv[i];
357                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
358                         cb.dry_run = 1;
359                 else if (!prefixcmp(arg, "--expire="))
360                         cb.expire_total = approxidate(arg + 9);
361                 else if (!prefixcmp(arg, "--expire-unreachable="))
362                         cb.expire_unreachable = approxidate(arg + 21);
363                 else if (!strcmp(arg, "--stale-fix"))
364                         cb.stalefix = 1;
365                 else if (!strcmp(arg, "--all"))
366                         do_all = 1;
367                 else if (!strcmp(arg, "--verbose"))
368                         cb.verbose = 1;
369                 else if (!strcmp(arg, "--")) {
370                         i++;
371                         break;
372                 }
373                 else if (arg[0] == '-')
374                         usage(reflog_expire_usage);
375                 else
376                         break;
377         }
378         if (cb.stalefix) {
379                 init_revisions(&cb.revs, prefix);
380                 if (cb.verbose)
381                         printf("Marking reachable objects...");
382                 mark_reachable_objects(&cb.revs, 0);
383                 if (cb.verbose)
384                         putchar('\n');
385         }
386
387         if (do_all) {
388                 struct collect_reflog_cb collected;
389                 int i;
390
391                 memset(&collected, 0, sizeof(collected));
392                 for_each_reflog(collect_reflog, &collected);
393                 for (i = 0; i < collected.nr; i++) {
394                         struct collected_reflog *e = collected.e[i];
395                         status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
396                         free(e);
397                 }
398                 free(collected.e);
399         }
400
401         while (i < argc) {
402                 const char *ref = argv[i++];
403                 unsigned char sha1[20];
404                 if (!resolve_ref(ref, sha1, 1, NULL)) {
405                         status |= error("%s points nowhere!", ref);
406                         continue;
407                 }
408                 status |= expire_reflog(ref, sha1, 0, &cb);
409         }
410         return status;
411 }
412
413 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
414                 const char *email, unsigned long timestamp, int tz,
415                 const char *message, void *cb_data)
416 {
417         struct cmd_reflog_expire_cb *cb = cb_data;
418         if (!cb->expire_total || timestamp < cb->expire_total)
419                 cb->recno++;
420         return 0;
421 }
422
423 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
424 {
425         struct cmd_reflog_expire_cb cb;
426         int i, status = 0;
427
428         if (argc < 2)
429                 return error("Nothing to delete?");
430
431         memset(&cb, 0, sizeof(cb));
432
433         for (i = 1; i < argc; i++) {
434                 const char *spec = strstr(argv[i], "@{");
435                 unsigned char sha1[20];
436                 char *ep, *ref;
437                 int recno;
438
439                 if (!spec) {
440                         status |= error("Not a reflog: %s", argv[i]);
441                         continue;
442                 }
443
444                 if (!dwim_ref(argv[i], spec - argv[i], sha1, &ref)) {
445                         status |= error("%s points nowhere!", argv[i]);
446                         continue;
447                 }
448
449                 recno = strtoul(spec + 2, &ep, 10);
450                 if (*ep == '}') {
451                         cb.recno = -recno;
452                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
453                 } else {
454                         cb.expire_total = approxidate(spec + 2);
455                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
456                         cb.expire_total = 0;
457                 }
458
459                 status |= expire_reflog(ref, sha1, 0, &cb);
460                 free(ref);
461         }
462         return status;
463 }
464
465 /*
466  * main "reflog"
467  */
468
469 static const char reflog_usage[] =
470 "git-reflog (expire | ...)";
471
472 int cmd_reflog(int argc, const char **argv, const char *prefix)
473 {
474         /* With no command, we default to showing it. */
475         if (argc < 2 || *argv[1] == '-')
476                 return cmd_log_reflog(argc, argv, prefix);
477
478         if (!strcmp(argv[1], "show"))
479                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
480
481         if (!strcmp(argv[1], "expire"))
482                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
483
484         if (!strcmp(argv[1], "delete"))
485                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
486
487         /* Not a recognized reflog command..*/
488         usage(reflog_usage);
489 }