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
15static const char reflog_expire_usage[] =
16"git-reflog expire [--verbose] [--dry-run] [--fix-stale] [--expire=<time>] [--expire-unreachable=<time>] [--all] <refs>...";
17
18static unsigned long default_reflog_expire;
19static unsigned long default_reflog_expire_unreachable;
20
21struct 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
30struct 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
40static 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 desc.buf = tree->buffer;
56 desc.size = tree->size;
57 if (!desc.buf) {
58 char type[20];
59 void *data = read_sha1_file(sha1, type, &desc.size);
60 if (!data) {
61 tree->object.flags |= INCOMPLETE;
62 return 0;
63 }
64 desc.buf = data;
65 tree->buffer = data;
66 }
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
83static 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
172static int keep_entry(struct commit **it, unsigned char *sha1)
173{
174 struct commit *commit;
175
176 *it = NULL;
177 if (is_null_sha1(sha1))
178 return 1;
179 commit = lookup_commit_reference_gently(sha1, 1);
180 if (!commit)
181 return 0;
182
183 /*
184 * Make sure everything in this commit exists.
185 *
186 * We have walked all the objects reachable from the refs
187 * and cache earlier. The commits reachable by this commit
188 * must meet SEEN commits -- and then we should mark them as
189 * SEEN as well.
190 */
191 if (!commit_is_complete(commit))
192 return 0;
193 *it = commit;
194 return 1;
195}
196
197static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
198 const char *email, unsigned long timestamp, int tz,
199 const char *message, void *cb_data)
200{
201 struct expire_reflog_cb *cb = cb_data;
202 struct commit *old, *new;
203
204 if (timestamp < cb->cmd->expire_total)
205 goto prune;
206
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 (!cb->ref_commit ||
213 (old && !in_merge_bases(old, cb->ref_commit)) ||
214 (new && !in_merge_bases(new, cb->ref_commit))))
215 goto prune;
216
217 if (cb->newlog) {
218 char sign = (tz < 0) ? '-' : '+';
219 int zone = (tz < 0) ? (-tz) : tz;
220 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
221 sha1_to_hex(osha1), sha1_to_hex(nsha1),
222 email, timestamp, sign, zone,
223 message);
224 }
225 if (cb->cmd->verbose)
226 printf("keep %s", message);
227 return 0;
228 prune:
229 if (!cb->newlog || cb->cmd->verbose)
230 printf("%sprune %s", cb->newlog ? "" : "would ", message);
231 return 0;
232}
233
234static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
235{
236 struct cmd_reflog_expire_cb *cmd = cb_data;
237 struct expire_reflog_cb cb;
238 struct ref_lock *lock;
239 char *newlog_path = NULL;
240 int status = 0;
241
242 if (strncmp(ref, "refs/", 5))
243 return error("not a ref '%s'", ref);
244
245 memset(&cb, 0, sizeof(cb));
246 /* we take the lock for the ref itself to prevent it from
247 * getting updated.
248 */
249 lock = lock_ref_sha1(ref + 5, sha1);
250 if (!lock)
251 return error("cannot lock ref '%s'", ref);
252 if (!file_exists(lock->log_file))
253 goto finish;
254 if (!cmd->dry_run) {
255 newlog_path = xstrdup(git_path("logs/%s.lock", ref));
256 cb.newlog = fopen(newlog_path, "w");
257 }
258
259 cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
260 if (!cb.ref_commit)
261 fprintf(stderr,
262 "warning: ref '%s' does not point at a commit\n", ref);
263 cb.ref = ref;
264 cb.cmd = cmd;
265 for_each_reflog_ent(ref, expire_reflog_ent, &cb);
266 finish:
267 if (cb.newlog) {
268 if (fclose(cb.newlog))
269 status |= error("%s: %s", strerror(errno),
270 newlog_path);
271 if (rename(newlog_path, lock->log_file)) {
272 status |= error("cannot rename %s to %s",
273 newlog_path, lock->log_file);
274 unlink(newlog_path);
275 }
276 }
277 free(newlog_path);
278 unlock_ref(lock);
279 return status;
280}
281
282static int reflog_expire_config(const char *var, const char *value)
283{
284 if (!strcmp(var, "gc.reflogexpire"))
285 default_reflog_expire = approxidate(value);
286 else if (!strcmp(var, "gc.reflogexpireunreachable"))
287 default_reflog_expire_unreachable = approxidate(value);
288 else
289 return git_default_config(var, value);
290 return 0;
291}
292
293static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
294{
295 struct cmd_reflog_expire_cb cb;
296 unsigned long now = time(NULL);
297 int i, status, do_all;
298
299 git_config(reflog_expire_config);
300
301 save_commit_buffer = 0;
302 do_all = status = 0;
303 memset(&cb, 0, sizeof(cb));
304
305 if (!default_reflog_expire_unreachable)
306 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
307 if (!default_reflog_expire)
308 default_reflog_expire = now - 90 * 24 * 3600;
309 cb.expire_total = default_reflog_expire;
310 cb.expire_unreachable = default_reflog_expire_unreachable;
311
312 /*
313 * We can trust the commits and objects reachable from refs
314 * even in older repository. We cannot trust what's reachable
315 * from reflog if the repository was pruned with older git.
316 */
317
318 for (i = 1; i < argc; i++) {
319 const char *arg = argv[i];
320 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
321 cb.dry_run = 1;
322 else if (!strncmp(arg, "--expire=", 9))
323 cb.expire_total = approxidate(arg + 9);
324 else if (!strncmp(arg, "--expire-unreachable=", 21))
325 cb.expire_unreachable = approxidate(arg + 21);
326 else if (!strcmp(arg, "--stale-fix"))
327 cb.stalefix = 1;
328 else if (!strcmp(arg, "--all"))
329 do_all = 1;
330 else if (!strcmp(arg, "--verbose"))
331 cb.verbose = 1;
332 else if (!strcmp(arg, "--")) {
333 i++;
334 break;
335 }
336 else if (arg[0] == '-')
337 usage(reflog_expire_usage);
338 else
339 break;
340 }
341 if (cb.stalefix) {
342 init_revisions(&cb.revs, prefix);
343 if (cb.verbose)
344 printf("Marking reachable objects...");
345 mark_reachable_objects(&cb.revs, 0);
346 if (cb.verbose)
347 putchar('\n');
348 }
349
350 if (do_all)
351 status |= for_each_ref(expire_reflog, &cb);
352 while (i < argc) {
353 const char *ref = argv[i++];
354 unsigned char sha1[20];
355 if (!resolve_ref(ref, sha1, 1, NULL)) {
356 status |= error("%s points nowhere!", ref);
357 continue;
358 }
359 status |= expire_reflog(ref, sha1, 0, &cb);
360 }
361 return status;
362}
363
364/*
365 * main "reflog"
366 */
367
368static const char reflog_usage[] =
369"git-reflog (expire | ...)";
370
371int cmd_reflog(int argc, const char **argv, const char *prefix)
372{
373 if (argc < 2)
374 usage(reflog_usage);
375 else if (!strcmp(argv[1], "expire"))
376 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
377 else
378 usage(reflog_usage);
379}