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