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