Merge branch 'tb/complete-describe'
[git/git.git] / builtin / gc.c
1 /*
2 * git gc builtin command
3 *
4 * Cleanup unreachable files and optimize the repository.
5 *
6 * Copyright (c) 2007 James Bowes
7 *
8 * Based on git-gc.sh, which is
9 *
10 * Copyright (c) 2006 Shawn O. Pearce
11 */
12
13 #include "builtin.h"
14 #include "config.h"
15 #include "tempfile.h"
16 #include "lockfile.h"
17 #include "parse-options.h"
18 #include "run-command.h"
19 #include "sigchain.h"
20 #include "argv-array.h"
21 #include "commit.h"
22 #include "packfile.h"
23
24 #define FAILED_RUN "failed to run %s"
25
26 static const char * const builtin_gc_usage[] = {
27 N_("git gc [<options>]"),
28 NULL
29 };
30
31 static int pack_refs = 1;
32 static int prune_reflogs = 1;
33 static int aggressive_depth = 50;
34 static int aggressive_window = 250;
35 static int gc_auto_threshold = 6700;
36 static int gc_auto_pack_limit = 50;
37 static int detach_auto = 1;
38 static timestamp_t gc_log_expire_time;
39 static const char *gc_log_expire = "1.day.ago";
40 static const char *prune_expire = "2.weeks.ago";
41 static const char *prune_worktrees_expire = "3.months.ago";
42
43 static struct argv_array pack_refs_cmd = ARGV_ARRAY_INIT;
44 static struct argv_array reflog = ARGV_ARRAY_INIT;
45 static struct argv_array repack = ARGV_ARRAY_INIT;
46 static struct argv_array prune = ARGV_ARRAY_INIT;
47 static struct argv_array prune_worktrees = ARGV_ARRAY_INIT;
48 static struct argv_array rerere = ARGV_ARRAY_INIT;
49
50 static struct tempfile *pidfile;
51 static struct lock_file log_lock;
52
53 static struct string_list pack_garbage = STRING_LIST_INIT_DUP;
54
55 static void clean_pack_garbage(void)
56 {
57 int i;
58 for (i = 0; i < pack_garbage.nr; i++)
59 unlink_or_warn(pack_garbage.items[i].string);
60 string_list_clear(&pack_garbage, 0);
61 }
62
63 static void report_pack_garbage(unsigned seen_bits, const char *path)
64 {
65 if (seen_bits == PACKDIR_FILE_IDX)
66 string_list_append(&pack_garbage, path);
67 }
68
69 static void process_log_file(void)
70 {
71 struct stat st;
72 if (fstat(get_lock_file_fd(&log_lock), &st)) {
73 /*
74 * Perhaps there was an i/o error or another
75 * unlikely situation. Try to make a note of
76 * this in gc.log along with any existing
77 * messages.
78 */
79 int saved_errno = errno;
80 fprintf(stderr, _("Failed to fstat %s: %s"),
81 get_tempfile_path(log_lock.tempfile),
82 strerror(saved_errno));
83 fflush(stderr);
84 commit_lock_file(&log_lock);
85 errno = saved_errno;
86 } else if (st.st_size) {
87 /* There was some error recorded in the lock file */
88 commit_lock_file(&log_lock);
89 } else {
90 /* No error, clean up any old gc.log */
91 unlink(git_path("gc.log"));
92 rollback_lock_file(&log_lock);
93 }
94 }
95
96 static void process_log_file_at_exit(void)
97 {
98 fflush(stderr);
99 process_log_file();
100 }
101
102 static void process_log_file_on_signal(int signo)
103 {
104 process_log_file();
105 sigchain_pop(signo);
106 raise(signo);
107 }
108
109 static void gc_config(void)
110 {
111 const char *value;
112
113 if (!git_config_get_value("gc.packrefs", &value)) {
114 if (value && !strcmp(value, "notbare"))
115 pack_refs = -1;
116 else
117 pack_refs = git_config_bool("gc.packrefs", value);
118 }
119
120 git_config_get_int("gc.aggressivewindow", &aggressive_window);
121 git_config_get_int("gc.aggressivedepth", &aggressive_depth);
122 git_config_get_int("gc.auto", &gc_auto_threshold);
123 git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
124 git_config_get_bool("gc.autodetach", &detach_auto);
125 git_config_get_expiry("gc.pruneexpire", &prune_expire);
126 git_config_get_expiry("gc.worktreepruneexpire", &prune_worktrees_expire);
127 git_config_get_expiry("gc.logexpiry", &gc_log_expire);
128
129 git_config(git_default_config, NULL);
130 }
131
132 static int too_many_loose_objects(void)
133 {
134 /*
135 * Quickly check if a "gc" is needed, by estimating how
136 * many loose objects there are. Because SHA-1 is evenly
137 * distributed, we can check only one and get a reasonable
138 * estimate.
139 */
140 DIR *dir;
141 struct dirent *ent;
142 int auto_threshold;
143 int num_loose = 0;
144 int needed = 0;
145
146 if (gc_auto_threshold <= 0)
147 return 0;
148
149 dir = opendir(git_path("objects/17"));
150 if (!dir)
151 return 0;
152
153 auto_threshold = DIV_ROUND_UP(gc_auto_threshold, 256);
154 while ((ent = readdir(dir)) != NULL) {
155 if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
156 ent->d_name[38] != '\0')
157 continue;
158 if (++num_loose > auto_threshold) {
159 needed = 1;
160 break;
161 }
162 }
163 closedir(dir);
164 return needed;
165 }
166
167 static int too_many_packs(void)
168 {
169 struct packed_git *p;
170 int cnt;
171
172 if (gc_auto_pack_limit <= 0)
173 return 0;
174
175 prepare_packed_git();
176 for (cnt = 0, p = packed_git; p; p = p->next) {
177 if (!p->pack_local)
178 continue;
179 if (p->pack_keep)
180 continue;
181 /*
182 * Perhaps check the size of the pack and count only
183 * very small ones here?
184 */
185 cnt++;
186 }
187 return gc_auto_pack_limit < cnt;
188 }
189
190 static void add_repack_all_option(void)
191 {
192 if (prune_expire && !strcmp(prune_expire, "now"))
193 argv_array_push(&repack, "-a");
194 else {
195 argv_array_push(&repack, "-A");
196 if (prune_expire)
197 argv_array_pushf(&repack, "--unpack-unreachable=%s", prune_expire);
198 }
199 }
200
201 static void add_repack_incremental_option(void)
202 {
203 argv_array_push(&repack, "--no-write-bitmap-index");
204 }
205
206 static int need_to_gc(void)
207 {
208 /*
209 * Setting gc.auto to 0 or negative can disable the
210 * automatic gc.
211 */
212 if (gc_auto_threshold <= 0)
213 return 0;
214
215 /*
216 * If there are too many loose objects, but not too many
217 * packs, we run "repack -d -l". If there are too many packs,
218 * we run "repack -A -d -l". Otherwise we tell the caller
219 * there is no need.
220 */
221 if (too_many_packs())
222 add_repack_all_option();
223 else if (too_many_loose_objects())
224 add_repack_incremental_option();
225 else
226 return 0;
227
228 if (run_hook_le(NULL, "pre-auto-gc", NULL))
229 return 0;
230 return 1;
231 }
232
233 /* return NULL on success, else hostname running the gc */
234 static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
235 {
236 static struct lock_file lock;
237 char my_host[HOST_NAME_MAX + 1];
238 struct strbuf sb = STRBUF_INIT;
239 struct stat st;
240 uintmax_t pid;
241 FILE *fp;
242 int fd;
243 char *pidfile_path;
244
245 if (is_tempfile_active(pidfile))
246 /* already locked */
247 return NULL;
248
249 if (xgethostname(my_host, sizeof(my_host)))
250 xsnprintf(my_host, sizeof(my_host), "unknown");
251
252 pidfile_path = git_pathdup("gc.pid");
253 fd = hold_lock_file_for_update(&lock, pidfile_path,
254 LOCK_DIE_ON_ERROR);
255 if (!force) {
256 static char locking_host[HOST_NAME_MAX + 1];
257 static char *scan_fmt;
258 int should_exit;
259
260 if (!scan_fmt)
261 scan_fmt = xstrfmt("%s %%%ds", "%"SCNuMAX, HOST_NAME_MAX);
262 fp = fopen(pidfile_path, "r");
263 memset(locking_host, 0, sizeof(locking_host));
264 should_exit =
265 fp != NULL &&
266 !fstat(fileno(fp), &st) &&
267 /*
268 * 12 hour limit is very generous as gc should
269 * never take that long. On the other hand we
270 * don't really need a strict limit here,
271 * running gc --auto one day late is not a big
272 * problem. --force can be used in manual gc
273 * after the user verifies that no gc is
274 * running.
275 */
276 time(NULL) - st.st_mtime <= 12 * 3600 &&
277 fscanf(fp, scan_fmt, &pid, locking_host) == 2 &&
278 /* be gentle to concurrent "gc" on remote hosts */
279 (strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM);
280 if (fp != NULL)
281 fclose(fp);
282 if (should_exit) {
283 if (fd >= 0)
284 rollback_lock_file(&lock);
285 *ret_pid = pid;
286 free(pidfile_path);
287 return locking_host;
288 }
289 }
290
291 strbuf_addf(&sb, "%"PRIuMAX" %s",
292 (uintmax_t) getpid(), my_host);
293 write_in_full(fd, sb.buf, sb.len);
294 strbuf_release(&sb);
295 commit_lock_file(&lock);
296 pidfile = register_tempfile(pidfile_path);
297 free(pidfile_path);
298 return NULL;
299 }
300
301 static int report_last_gc_error(void)
302 {
303 struct strbuf sb = STRBUF_INIT;
304 int ret = 0;
305 struct stat st;
306 char *gc_log_path = git_pathdup("gc.log");
307
308 if (stat(gc_log_path, &st)) {
309 if (errno == ENOENT)
310 goto done;
311
312 ret = error_errno(_("Can't stat %s"), gc_log_path);
313 goto done;
314 }
315
316 if (st.st_mtime < gc_log_expire_time)
317 goto done;
318
319 ret = strbuf_read_file(&sb, gc_log_path, 0);
320 if (ret > 0)
321 ret = error(_("The last gc run reported the following. "
322 "Please correct the root cause\n"
323 "and remove %s.\n"
324 "Automatic cleanup will not be performed "
325 "until the file is removed.\n\n"
326 "%s"),
327 gc_log_path, sb.buf);
328 strbuf_release(&sb);
329 done:
330 free(gc_log_path);
331 return ret;
332 }
333
334 static int gc_before_repack(void)
335 {
336 if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
337 return error(FAILED_RUN, pack_refs_cmd.argv[0]);
338
339 if (prune_reflogs && run_command_v_opt(reflog.argv, RUN_GIT_CMD))
340 return error(FAILED_RUN, reflog.argv[0]);
341
342 pack_refs = 0;
343 prune_reflogs = 0;
344 return 0;
345 }
346
347 int cmd_gc(int argc, const char **argv, const char *prefix)
348 {
349 int aggressive = 0;
350 int auto_gc = 0;
351 int quiet = 0;
352 int force = 0;
353 const char *name;
354 pid_t pid;
355 int daemonized = 0;
356
357 struct option builtin_gc_options[] = {
358 OPT__QUIET(&quiet, N_("suppress progress reporting")),
359 { OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
360 N_("prune unreferenced objects"),
361 PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
362 OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
363 OPT_BOOL(0, "auto", &auto_gc, N_("enable auto-gc mode")),
364 OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")),
365 OPT_END()
366 };
367
368 if (argc == 2 && !strcmp(argv[1], "-h"))
369 usage_with_options(builtin_gc_usage, builtin_gc_options);
370
371 argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
372 argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL);
373 argv_array_pushl(&repack, "repack", "-d", "-l", NULL);
374 argv_array_pushl(&prune, "prune", "--expire", NULL);
375 argv_array_pushl(&prune_worktrees, "worktree", "prune", "--expire", NULL);
376 argv_array_pushl(&rerere, "rerere", "gc", NULL);
377
378 /* default expiry time, overwritten in gc_config */
379 gc_config();
380 if (parse_expiry_date(gc_log_expire, &gc_log_expire_time))
381 die(_("Failed to parse gc.logexpiry value %s"), gc_log_expire);
382
383 if (pack_refs < 0)
384 pack_refs = !is_bare_repository();
385
386 argc = parse_options(argc, argv, prefix, builtin_gc_options,
387 builtin_gc_usage, 0);
388 if (argc > 0)
389 usage_with_options(builtin_gc_usage, builtin_gc_options);
390
391 if (aggressive) {
392 argv_array_push(&repack, "-f");
393 if (aggressive_depth > 0)
394 argv_array_pushf(&repack, "--depth=%d", aggressive_depth);
395 if (aggressive_window > 0)
396 argv_array_pushf(&repack, "--window=%d", aggressive_window);
397 }
398 if (quiet)
399 argv_array_push(&repack, "-q");
400
401 if (auto_gc) {
402 /*
403 * Auto-gc should be least intrusive as possible.
404 */
405 if (!need_to_gc())
406 return 0;
407 if (!quiet) {
408 if (detach_auto)
409 fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n"));
410 else
411 fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
412 fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n"));
413 }
414 if (detach_auto) {
415 if (report_last_gc_error())
416 return -1;
417
418 if (lock_repo_for_gc(force, &pid))
419 return 0;
420 if (gc_before_repack())
421 return -1;
422 delete_tempfile(&pidfile);
423
424 /*
425 * failure to daemonize is ok, we'll continue
426 * in foreground
427 */
428 daemonized = !daemonize();
429 }
430 } else
431 add_repack_all_option();
432
433 name = lock_repo_for_gc(force, &pid);
434 if (name) {
435 if (auto_gc)
436 return 0; /* be quiet on --auto */
437 die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
438 name, (uintmax_t)pid);
439 }
440
441 if (daemonized) {
442 hold_lock_file_for_update(&log_lock,
443 git_path("gc.log"),
444 LOCK_DIE_ON_ERROR);
445 dup2(get_lock_file_fd(&log_lock), 2);
446 sigchain_push_common(process_log_file_on_signal);
447 atexit(process_log_file_at_exit);
448 }
449
450 if (gc_before_repack())
451 return -1;
452
453 if (!repository_format_precious_objects) {
454 if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
455 return error(FAILED_RUN, repack.argv[0]);
456
457 if (prune_expire) {
458 argv_array_push(&prune, prune_expire);
459 if (quiet)
460 argv_array_push(&prune, "--no-progress");
461 if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
462 return error(FAILED_RUN, prune.argv[0]);
463 }
464 }
465
466 if (prune_worktrees_expire) {
467 argv_array_push(&prune_worktrees, prune_worktrees_expire);
468 if (run_command_v_opt(prune_worktrees.argv, RUN_GIT_CMD))
469 return error(FAILED_RUN, prune_worktrees.argv[0]);
470 }
471
472 if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
473 return error(FAILED_RUN, rerere.argv[0]);
474
475 report_garbage = report_pack_garbage;
476 reprepare_packed_git();
477 if (pack_garbage.nr > 0)
478 clean_pack_garbage();
479
480 if (auto_gc && too_many_loose_objects())
481 warning(_("There are too many unreachable loose objects; "
482 "run 'git prune' to remove them."));
483
484 if (!daemonized)
485 unlink(git_path("gc.log"));
486
487 return 0;
488 }