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