object-store: move packed_git and packed_git_mru to object store
[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 "repository.h"
15 #include "config.h"
16 #include "tempfile.h"
17 #include "lockfile.h"
18 #include "parse-options.h"
19 #include "run-command.h"
20 #include "sigchain.h"
21 #include "argv-array.h"
22 #include "commit.h"
23 #include "packfile.h"
24 #include "object-store.h"
25
26 #define FAILED_RUN "failed to run %s"
27
28 static const char * const builtin_gc_usage[] = {
29 N_("git gc [<options>]"),
30 NULL
31 };
32
33 static int pack_refs = 1;
34 static int prune_reflogs = 1;
35 static int aggressive_depth = 50;
36 static int aggressive_window = 250;
37 static int gc_auto_threshold = 6700;
38 static int gc_auto_pack_limit = 50;
39 static int detach_auto = 1;
40 static timestamp_t gc_log_expire_time;
41 static const char *gc_log_expire = "1.day.ago";
42 static const char *prune_expire = "2.weeks.ago";
43 static const char *prune_worktrees_expire = "3.months.ago";
44
45 static struct argv_array pack_refs_cmd = ARGV_ARRAY_INIT;
46 static struct argv_array reflog = ARGV_ARRAY_INIT;
47 static struct argv_array repack = ARGV_ARRAY_INIT;
48 static struct argv_array prune = ARGV_ARRAY_INIT;
49 static struct argv_array prune_worktrees = ARGV_ARRAY_INIT;
50 static struct argv_array rerere = ARGV_ARRAY_INIT;
51
52 static struct tempfile *pidfile;
53 static struct lock_file log_lock;
54
55 static struct string_list pack_garbage = STRING_LIST_INIT_DUP;
56
57 static void clean_pack_garbage(void)
58 {
59 int i;
60 for (i = 0; i < pack_garbage.nr; i++)
61 unlink_or_warn(pack_garbage.items[i].string);
62 string_list_clear(&pack_garbage, 0);
63 }
64
65 static void report_pack_garbage(unsigned seen_bits, const char *path)
66 {
67 if (seen_bits == PACKDIR_FILE_IDX)
68 string_list_append(&pack_garbage, path);
69 }
70
71 static void process_log_file(void)
72 {
73 struct stat st;
74 if (fstat(get_lock_file_fd(&log_lock), &st)) {
75 /*
76 * Perhaps there was an i/o error or another
77 * unlikely situation. Try to make a note of
78 * this in gc.log along with any existing
79 * messages.
80 */
81 int saved_errno = errno;
82 fprintf(stderr, _("Failed to fstat %s: %s"),
83 get_tempfile_path(log_lock.tempfile),
84 strerror(saved_errno));
85 fflush(stderr);
86 commit_lock_file(&log_lock);
87 errno = saved_errno;
88 } else if (st.st_size) {
89 /* There was some error recorded in the lock file */
90 commit_lock_file(&log_lock);
91 } else {
92 /* No error, clean up any old gc.log */
93 unlink(git_path("gc.log"));
94 rollback_lock_file(&log_lock);
95 }
96 }
97
98 static void process_log_file_at_exit(void)
99 {
100 fflush(stderr);
101 process_log_file();
102 }
103
104 static void process_log_file_on_signal(int signo)
105 {
106 process_log_file();
107 sigchain_pop(signo);
108 raise(signo);
109 }
110
111 static void gc_config(void)
112 {
113 const char *value;
114
115 if (!git_config_get_value("gc.packrefs", &value)) {
116 if (value && !strcmp(value, "notbare"))
117 pack_refs = -1;
118 else
119 pack_refs = git_config_bool("gc.packrefs", value);
120 }
121
122 git_config_get_int("gc.aggressivewindow", &aggressive_window);
123 git_config_get_int("gc.aggressivedepth", &aggressive_depth);
124 git_config_get_int("gc.auto", &gc_auto_threshold);
125 git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
126 git_config_get_bool("gc.autodetach", &detach_auto);
127 git_config_get_expiry("gc.pruneexpire", &prune_expire);
128 git_config_get_expiry("gc.worktreepruneexpire", &prune_worktrees_expire);
129 git_config_get_expiry("gc.logexpiry", &gc_log_expire);
130
131 git_config(git_default_config, NULL);
132 }
133
134 static int too_many_loose_objects(void)
135 {
136 /*
137 * Quickly check if a "gc" is needed, by estimating how
138 * many loose objects there are. Because SHA-1 is evenly
139 * distributed, we can check only one and get a reasonable
140 * estimate.
141 */
142 DIR *dir;
143 struct dirent *ent;
144 int auto_threshold;
145 int num_loose = 0;
146 int needed = 0;
147
148 if (gc_auto_threshold <= 0)
149 return 0;
150
151 dir = opendir(git_path("objects/17"));
152 if (!dir)
153 return 0;
154
155 auto_threshold = DIV_ROUND_UP(gc_auto_threshold, 256);
156 while ((ent = readdir(dir)) != NULL) {
157 if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
158 ent->d_name[38] != '\0')
159 continue;
160 if (++num_loose > auto_threshold) {
161 needed = 1;
162 break;
163 }
164 }
165 closedir(dir);
166 return needed;
167 }
168
169 static int too_many_packs(void)
170 {
171 struct packed_git *p;
172 int cnt;
173
174 if (gc_auto_pack_limit <= 0)
175 return 0;
176
177 prepare_packed_git();
178 for (cnt = 0, p = get_packed_git(the_repository); p; p = p->next) {
179 if (!p->pack_local)
180 continue;
181 if (p->pack_keep)
182 continue;
183 /*
184 * Perhaps check the size of the pack and count only
185 * very small ones here?
186 */
187 cnt++;
188 }
189 return gc_auto_pack_limit < cnt;
190 }
191
192 static void add_repack_all_option(void)
193 {
194 if (prune_expire && !strcmp(prune_expire, "now"))
195 argv_array_push(&repack, "-a");
196 else {
197 argv_array_push(&repack, "-A");
198 if (prune_expire)
199 argv_array_pushf(&repack, "--unpack-unreachable=%s", prune_expire);
200 }
201 }
202
203 static void add_repack_incremental_option(void)
204 {
205 argv_array_push(&repack, "--no-write-bitmap-index");
206 }
207
208 static int need_to_gc(void)
209 {
210 /*
211 * Setting gc.auto to 0 or negative can disable the
212 * automatic gc.
213 */
214 if (gc_auto_threshold <= 0)
215 return 0;
216
217 /*
218 * If there are too many loose objects, but not too many
219 * packs, we run "repack -d -l". If there are too many packs,
220 * we run "repack -A -d -l". Otherwise we tell the caller
221 * there is no need.
222 */
223 if (too_many_packs())
224 add_repack_all_option();
225 else if (too_many_loose_objects())
226 add_repack_incremental_option();
227 else
228 return 0;
229
230 if (run_hook_le(NULL, "pre-auto-gc", NULL))
231 return 0;
232 return 1;
233 }
234
235 /* return NULL on success, else hostname running the gc */
236 static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
237 {
238 static struct lock_file lock;
239 char my_host[HOST_NAME_MAX + 1];
240 struct strbuf sb = STRBUF_INIT;
241 struct stat st;
242 uintmax_t pid;
243 FILE *fp;
244 int fd;
245 char *pidfile_path;
246
247 if (is_tempfile_active(pidfile))
248 /* already locked */
249 return NULL;
250
251 if (xgethostname(my_host, sizeof(my_host)))
252 xsnprintf(my_host, sizeof(my_host), "unknown");
253
254 pidfile_path = git_pathdup("gc.pid");
255 fd = hold_lock_file_for_update(&lock, pidfile_path,
256 LOCK_DIE_ON_ERROR);
257 if (!force) {
258 static char locking_host[HOST_NAME_MAX + 1];
259 static char *scan_fmt;
260 int should_exit;
261
262 if (!scan_fmt)
263 scan_fmt = xstrfmt("%s %%%ds", "%"SCNuMAX, HOST_NAME_MAX);
264 fp = fopen(pidfile_path, "r");
265 memset(locking_host, 0, sizeof(locking_host));
266 should_exit =
267 fp != NULL &&
268 !fstat(fileno(fp), &st) &&
269 /*
270 * 12 hour limit is very generous as gc should
271 * never take that long. On the other hand we
272 * don't really need a strict limit here,
273 * running gc --auto one day late is not a big
274 * problem. --force can be used in manual gc
275 * after the user verifies that no gc is
276 * running.
277 */
278 time(NULL) - st.st_mtime <= 12 * 3600 &&
279 fscanf(fp, scan_fmt, &pid, locking_host) == 2 &&
280 /* be gentle to concurrent "gc" on remote hosts */
281 (strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM);
282 if (fp != NULL)
283 fclose(fp);
284 if (should_exit) {
285 if (fd >= 0)
286 rollback_lock_file(&lock);
287 *ret_pid = pid;
288 free(pidfile_path);
289 return locking_host;
290 }
291 }
292
293 strbuf_addf(&sb, "%"PRIuMAX" %s",
294 (uintmax_t) getpid(), my_host);
295 write_in_full(fd, sb.buf, sb.len);
296 strbuf_release(&sb);
297 commit_lock_file(&lock);
298 pidfile = register_tempfile(pidfile_path);
299 free(pidfile_path);
300 return NULL;
301 }
302
303 static int report_last_gc_error(void)
304 {
305 struct strbuf sb = STRBUF_INIT;
306 int ret = 0;
307 struct stat st;
308 char *gc_log_path = git_pathdup("gc.log");
309
310 if (stat(gc_log_path, &st)) {
311 if (errno == ENOENT)
312 goto done;
313
314 ret = error_errno(_("Can't stat %s"), gc_log_path);
315 goto done;
316 }
317
318 if (st.st_mtime < gc_log_expire_time)
319 goto done;
320
321 ret = strbuf_read_file(&sb, gc_log_path, 0);
322 if (ret > 0)
323 ret = error(_("The last gc run reported the following. "
324 "Please correct the root cause\n"
325 "and remove %s.\n"
326 "Automatic cleanup will not be performed "
327 "until the file is removed.\n\n"
328 "%s"),
329 gc_log_path, sb.buf);
330 strbuf_release(&sb);
331 done:
332 free(gc_log_path);
333 return ret;
334 }
335
336 static int gc_before_repack(void)
337 {
338 if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
339 return error(FAILED_RUN, pack_refs_cmd.argv[0]);
340
341 if (prune_reflogs && run_command_v_opt(reflog.argv, RUN_GIT_CMD))
342 return error(FAILED_RUN, reflog.argv[0]);
343
344 pack_refs = 0;
345 prune_reflogs = 0;
346 return 0;
347 }
348
349 int cmd_gc(int argc, const char **argv, const char *prefix)
350 {
351 int aggressive = 0;
352 int auto_gc = 0;
353 int quiet = 0;
354 int force = 0;
355 const char *name;
356 pid_t pid;
357 int daemonized = 0;
358
359 struct option builtin_gc_options[] = {
360 OPT__QUIET(&quiet, N_("suppress progress reporting")),
361 { OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
362 N_("prune unreferenced objects"),
363 PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
364 OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
365 OPT_BOOL(0, "auto", &auto_gc, N_("enable auto-gc mode")),
366 OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")),
367 OPT_END()
368 };
369
370 if (argc == 2 && !strcmp(argv[1], "-h"))
371 usage_with_options(builtin_gc_usage, builtin_gc_options);
372
373 argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
374 argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL);
375 argv_array_pushl(&repack, "repack", "-d", "-l", NULL);
376 argv_array_pushl(&prune, "prune", "--expire", NULL);
377 argv_array_pushl(&prune_worktrees, "worktree", "prune", "--expire", NULL);
378 argv_array_pushl(&rerere, "rerere", "gc", NULL);
379
380 /* default expiry time, overwritten in gc_config */
381 gc_config();
382 if (parse_expiry_date(gc_log_expire, &gc_log_expire_time))
383 die(_("Failed to parse gc.logexpiry value %s"), gc_log_expire);
384
385 if (pack_refs < 0)
386 pack_refs = !is_bare_repository();
387
388 argc = parse_options(argc, argv, prefix, builtin_gc_options,
389 builtin_gc_usage, 0);
390 if (argc > 0)
391 usage_with_options(builtin_gc_usage, builtin_gc_options);
392
393 if (aggressive) {
394 argv_array_push(&repack, "-f");
395 if (aggressive_depth > 0)
396 argv_array_pushf(&repack, "--depth=%d", aggressive_depth);
397 if (aggressive_window > 0)
398 argv_array_pushf(&repack, "--window=%d", aggressive_window);
399 }
400 if (quiet)
401 argv_array_push(&repack, "-q");
402
403 if (auto_gc) {
404 /*
405 * Auto-gc should be least intrusive as possible.
406 */
407 if (!need_to_gc())
408 return 0;
409 if (!quiet) {
410 if (detach_auto)
411 fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n"));
412 else
413 fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
414 fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n"));
415 }
416 if (detach_auto) {
417 if (report_last_gc_error())
418 return -1;
419
420 if (lock_repo_for_gc(force, &pid))
421 return 0;
422 if (gc_before_repack())
423 return -1;
424 delete_tempfile(&pidfile);
425
426 /*
427 * failure to daemonize is ok, we'll continue
428 * in foreground
429 */
430 daemonized = !daemonize();
431 }
432 } else
433 add_repack_all_option();
434
435 name = lock_repo_for_gc(force, &pid);
436 if (name) {
437 if (auto_gc)
438 return 0; /* be quiet on --auto */
439 die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
440 name, (uintmax_t)pid);
441 }
442
443 if (daemonized) {
444 hold_lock_file_for_update(&log_lock,
445 git_path("gc.log"),
446 LOCK_DIE_ON_ERROR);
447 dup2(get_lock_file_fd(&log_lock), 2);
448 sigchain_push_common(process_log_file_on_signal);
449 atexit(process_log_file_at_exit);
450 }
451
452 if (gc_before_repack())
453 return -1;
454
455 if (!repository_format_precious_objects) {
456 if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
457 return error(FAILED_RUN, repack.argv[0]);
458
459 if (prune_expire) {
460 argv_array_push(&prune, prune_expire);
461 if (quiet)
462 argv_array_push(&prune, "--no-progress");
463 if (repository_format_partial_clone)
464 argv_array_push(&prune,
465 "--exclude-promisor-objects");
466 if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
467 return error(FAILED_RUN, prune.argv[0]);
468 }
469 }
470
471 if (prune_worktrees_expire) {
472 argv_array_push(&prune_worktrees, prune_worktrees_expire);
473 if (run_command_v_opt(prune_worktrees.argv, RUN_GIT_CMD))
474 return error(FAILED_RUN, prune_worktrees.argv[0]);
475 }
476
477 if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
478 return error(FAILED_RUN, rerere.argv[0]);
479
480 report_garbage = report_pack_garbage;
481 reprepare_packed_git();
482 if (pack_garbage.nr > 0)
483 clean_pack_garbage();
484
485 if (auto_gc && too_many_loose_objects())
486 warning(_("There are too many unreachable loose objects; "
487 "run 'git prune' to remove them."));
488
489 if (!daemonized)
490 unlink(git_path("gc.log"));
491
492 return 0;
493 }