Merge branch 'mh/maint-http-proxy-fix'
[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                         unlink(newlog_path);
283                 } else if (rename(newlog_path, log_file)) {
284                         status |= error("cannot rename %s to %s",
285                                         newlog_path, log_file);
286                         unlink(newlog_path);
287                 }
288         }
289         free(newlog_path);
290         free(log_file);
291         unlock_ref(lock);
292         return status;
293 }
294
295 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
296 {
297         struct collected_reflog *e;
298         struct collect_reflog_cb *cb = cb_data;
299         size_t namelen = strlen(ref);
300
301         e = xmalloc(sizeof(*e) + namelen + 1);
302         hashcpy(e->sha1, sha1);
303         memcpy(e->reflog, ref, namelen + 1);
304         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
305         cb->e[cb->nr++] = e;
306         return 0;
307 }
308
309 static int reflog_expire_config(const char *var, const char *value)
310 {
311         if (!strcmp(var, "gc.reflogexpire")) {
312                 if (!value)
313                         config_error_nonbool(var);
314                 default_reflog_expire = approxidate(value);
315                 return 0;
316         }
317         if (!strcmp(var, "gc.reflogexpireunreachable")) {
318                 if (!value)
319                         config_error_nonbool(var);
320                 default_reflog_expire_unreachable = approxidate(value);
321                 return 0;
322         }
323         return git_default_config(var, value);
324 }
325
326 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
327 {
328         struct cmd_reflog_expire_cb cb;
329         unsigned long now = time(NULL);
330         int i, status, do_all;
331
332         git_config(reflog_expire_config);
333
334         save_commit_buffer = 0;
335         do_all = status = 0;
336         memset(&cb, 0, sizeof(cb));
337
338         if (!default_reflog_expire_unreachable)
339                 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
340         if (!default_reflog_expire)
341                 default_reflog_expire = now - 90 * 24 * 3600;
342         cb.expire_total = default_reflog_expire;
343         cb.expire_unreachable = default_reflog_expire_unreachable;
344
345         /*
346          * We can trust the commits and objects reachable from refs
347          * even in older repository.  We cannot trust what's reachable
348          * from reflog if the repository was pruned with older git.
349          */
350
351         for (i = 1; i < argc; i++) {
352                 const char *arg = argv[i];
353                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
354                         cb.dry_run = 1;
355                 else if (!prefixcmp(arg, "--expire="))
356                         cb.expire_total = approxidate(arg + 9);
357                 else if (!prefixcmp(arg, "--expire-unreachable="))
358                         cb.expire_unreachable = approxidate(arg + 21);
359                 else if (!strcmp(arg, "--stale-fix"))
360                         cb.stalefix = 1;
361                 else if (!strcmp(arg, "--all"))
362                         do_all = 1;
363                 else if (!strcmp(arg, "--verbose"))
364                         cb.verbose = 1;
365                 else if (!strcmp(arg, "--")) {
366                         i++;
367                         break;
368                 }
369                 else if (arg[0] == '-')
370                         usage(reflog_expire_usage);
371                 else
372                         break;
373         }
374         if (cb.stalefix) {
375                 init_revisions(&cb.revs, prefix);
376                 if (cb.verbose)
377                         printf("Marking reachable objects...");
378                 mark_reachable_objects(&cb.revs, 0);
379                 if (cb.verbose)
380                         putchar('\n');
381         }
382
383         if (do_all) {
384                 struct collect_reflog_cb collected;
385                 int i;
386
387                 memset(&collected, 0, sizeof(collected));
388                 for_each_reflog(collect_reflog, &collected);
389                 for (i = 0; i < collected.nr; i++) {
390                         struct collected_reflog *e = collected.e[i];
391                         status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
392                         free(e);
393                 }
394                 free(collected.e);
395         }
396
397         while (i < argc) {
398                 const char *ref = argv[i++];
399                 unsigned char sha1[20];
400                 if (!resolve_ref(ref, sha1, 1, NULL)) {
401                         status |= error("%s points nowhere!", ref);
402                         continue;
403                 }
404                 status |= expire_reflog(ref, sha1, 0, &cb);
405         }
406         return status;
407 }
408
409 /*
410  * main "reflog"
411  */
412
413 static const char reflog_usage[] =
414 "git-reflog (expire | ...)";
415
416 int cmd_reflog(int argc, const char **argv, const char *prefix)
417 {
418         /* With no command, we default to showing it. */
419         if (argc < 2 || *argv[1] == '-')
420                 return cmd_log_reflog(argc, argv, prefix);
421
422         if (!strcmp(argv[1], "show"))
423                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
424
425         if (!strcmp(argv[1], "expire"))
426                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
427
428         /* Not a recognized reflog command..*/
429         usage(reflog_usage);
430 }