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[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 "strvec.h"
22 #include "commit.h"
23 #include "commit-graph.h"
24 #include "packfile.h"
25 #include "object-store.h"
26 #include "pack.h"
27 #include "pack-objects.h"
28 #include "blob.h"
29 #include "tree.h"
30 #include "promisor-remote.h"
31 #include "refs.h"
32 #include "remote.h"
33 #include "object-store.h"
34 #include "exec-cmd.h"
35
36 #define FAILED_RUN "failed to run %s"
37
38 static const char * const builtin_gc_usage[] = {
39         N_("git gc [<options>]"),
40         NULL
41 };
42
43 static int pack_refs = 1;
44 static int prune_reflogs = 1;
45 static int aggressive_depth = 50;
46 static int aggressive_window = 250;
47 static int gc_auto_threshold = 6700;
48 static int gc_auto_pack_limit = 50;
49 static int detach_auto = 1;
50 static timestamp_t gc_log_expire_time;
51 static const char *gc_log_expire = "1.day.ago";
52 static const char *prune_expire = "2.weeks.ago";
53 static const char *prune_worktrees_expire = "3.months.ago";
54 static unsigned long big_pack_threshold;
55 static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
56
57 static struct strvec reflog = STRVEC_INIT;
58 static struct strvec repack = STRVEC_INIT;
59 static struct strvec prune = STRVEC_INIT;
60 static struct strvec prune_worktrees = STRVEC_INIT;
61 static struct strvec rerere = STRVEC_INIT;
62
63 static struct tempfile *pidfile;
64 static struct lock_file log_lock;
65
66 static struct string_list pack_garbage = STRING_LIST_INIT_DUP;
67
68 static void clean_pack_garbage(void)
69 {
70         int i;
71         for (i = 0; i < pack_garbage.nr; i++)
72                 unlink_or_warn(pack_garbage.items[i].string);
73         string_list_clear(&pack_garbage, 0);
74 }
75
76 static void report_pack_garbage(unsigned seen_bits, const char *path)
77 {
78         if (seen_bits == PACKDIR_FILE_IDX)
79                 string_list_append(&pack_garbage, path);
80 }
81
82 static void process_log_file(void)
83 {
84         struct stat st;
85         if (fstat(get_lock_file_fd(&log_lock), &st)) {
86                 /*
87                  * Perhaps there was an i/o error or another
88                  * unlikely situation.  Try to make a note of
89                  * this in gc.log along with any existing
90                  * messages.
91                  */
92                 int saved_errno = errno;
93                 fprintf(stderr, _("Failed to fstat %s: %s"),
94                         get_lock_file_path(&log_lock),
95                         strerror(saved_errno));
96                 fflush(stderr);
97                 commit_lock_file(&log_lock);
98                 errno = saved_errno;
99         } else if (st.st_size) {
100                 /* There was some error recorded in the lock file */
101                 commit_lock_file(&log_lock);
102         } else {
103                 /* No error, clean up any old gc.log */
104                 unlink(git_path("gc.log"));
105                 rollback_lock_file(&log_lock);
106         }
107 }
108
109 static void process_log_file_at_exit(void)
110 {
111         fflush(stderr);
112         process_log_file();
113 }
114
115 static void process_log_file_on_signal(int signo)
116 {
117         process_log_file();
118         sigchain_pop(signo);
119         raise(signo);
120 }
121
122 static int gc_config_is_timestamp_never(const char *var)
123 {
124         const char *value;
125         timestamp_t expire;
126
127         if (!git_config_get_value(var, &value) && value) {
128                 if (parse_expiry_date(value, &expire))
129                         die(_("failed to parse '%s' value '%s'"), var, value);
130                 return expire == 0;
131         }
132         return 0;
133 }
134
135 static void gc_config(void)
136 {
137         const char *value;
138
139         if (!git_config_get_value("gc.packrefs", &value)) {
140                 if (value && !strcmp(value, "notbare"))
141                         pack_refs = -1;
142                 else
143                         pack_refs = git_config_bool("gc.packrefs", value);
144         }
145
146         if (gc_config_is_timestamp_never("gc.reflogexpire") &&
147             gc_config_is_timestamp_never("gc.reflogexpireunreachable"))
148                 prune_reflogs = 0;
149
150         git_config_get_int("gc.aggressivewindow", &aggressive_window);
151         git_config_get_int("gc.aggressivedepth", &aggressive_depth);
152         git_config_get_int("gc.auto", &gc_auto_threshold);
153         git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
154         git_config_get_bool("gc.autodetach", &detach_auto);
155         git_config_get_expiry("gc.pruneexpire", &prune_expire);
156         git_config_get_expiry("gc.worktreepruneexpire", &prune_worktrees_expire);
157         git_config_get_expiry("gc.logexpiry", &gc_log_expire);
158
159         git_config_get_ulong("gc.bigpackthreshold", &big_pack_threshold);
160         git_config_get_ulong("pack.deltacachesize", &max_delta_cache_size);
161
162         git_config(git_default_config, NULL);
163 }
164
165 struct maintenance_run_opts;
166 static int maintenance_task_pack_refs(MAYBE_UNUSED struct maintenance_run_opts *opts)
167 {
168         struct strvec pack_refs_cmd = STRVEC_INIT;
169         strvec_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
170
171         return run_command_v_opt(pack_refs_cmd.v, RUN_GIT_CMD);
172 }
173
174 static int too_many_loose_objects(void)
175 {
176         /*
177          * Quickly check if a "gc" is needed, by estimating how
178          * many loose objects there are.  Because SHA-1 is evenly
179          * distributed, we can check only one and get a reasonable
180          * estimate.
181          */
182         DIR *dir;
183         struct dirent *ent;
184         int auto_threshold;
185         int num_loose = 0;
186         int needed = 0;
187         const unsigned hexsz_loose = the_hash_algo->hexsz - 2;
188
189         dir = opendir(git_path("objects/17"));
190         if (!dir)
191                 return 0;
192
193         auto_threshold = DIV_ROUND_UP(gc_auto_threshold, 256);
194         while ((ent = readdir(dir)) != NULL) {
195                 if (strspn(ent->d_name, "0123456789abcdef") != hexsz_loose ||
196                     ent->d_name[hexsz_loose] != '\0')
197                         continue;
198                 if (++num_loose > auto_threshold) {
199                         needed = 1;
200                         break;
201                 }
202         }
203         closedir(dir);
204         return needed;
205 }
206
207 static struct packed_git *find_base_packs(struct string_list *packs,
208                                           unsigned long limit)
209 {
210         struct packed_git *p, *base = NULL;
211
212         for (p = get_all_packs(the_repository); p; p = p->next) {
213                 if (!p->pack_local)
214                         continue;
215                 if (limit) {
216                         if (p->pack_size >= limit)
217                                 string_list_append(packs, p->pack_name);
218                 } else if (!base || base->pack_size < p->pack_size) {
219                         base = p;
220                 }
221         }
222
223         if (base)
224                 string_list_append(packs, base->pack_name);
225
226         return base;
227 }
228
229 static int too_many_packs(void)
230 {
231         struct packed_git *p;
232         int cnt;
233
234         if (gc_auto_pack_limit <= 0)
235                 return 0;
236
237         for (cnt = 0, p = get_all_packs(the_repository); p; p = p->next) {
238                 if (!p->pack_local)
239                         continue;
240                 if (p->pack_keep)
241                         continue;
242                 /*
243                  * Perhaps check the size of the pack and count only
244                  * very small ones here?
245                  */
246                 cnt++;
247         }
248         return gc_auto_pack_limit < cnt;
249 }
250
251 static uint64_t total_ram(void)
252 {
253 #if defined(HAVE_SYSINFO)
254         struct sysinfo si;
255
256         if (!sysinfo(&si))
257                 return si.totalram;
258 #elif defined(HAVE_BSD_SYSCTL) && (defined(HW_MEMSIZE) || defined(HW_PHYSMEM))
259         int64_t physical_memory;
260         int mib[2];
261         size_t length;
262
263         mib[0] = CTL_HW;
264 # if defined(HW_MEMSIZE)
265         mib[1] = HW_MEMSIZE;
266 # else
267         mib[1] = HW_PHYSMEM;
268 # endif
269         length = sizeof(int64_t);
270         if (!sysctl(mib, 2, &physical_memory, &length, NULL, 0))
271                 return physical_memory;
272 #elif defined(GIT_WINDOWS_NATIVE)
273         MEMORYSTATUSEX memInfo;
274
275         memInfo.dwLength = sizeof(MEMORYSTATUSEX);
276         if (GlobalMemoryStatusEx(&memInfo))
277                 return memInfo.ullTotalPhys;
278 #endif
279         return 0;
280 }
281
282 static uint64_t estimate_repack_memory(struct packed_git *pack)
283 {
284         unsigned long nr_objects = approximate_object_count();
285         size_t os_cache, heap;
286
287         if (!pack || !nr_objects)
288                 return 0;
289
290         /*
291          * First we have to scan through at least one pack.
292          * Assume enough room in OS file cache to keep the entire pack
293          * or we may accidentally evict data of other processes from
294          * the cache.
295          */
296         os_cache = pack->pack_size + pack->index_size;
297         /* then pack-objects needs lots more for book keeping */
298         heap = sizeof(struct object_entry) * nr_objects;
299         /*
300          * internal rev-list --all --objects takes up some memory too,
301          * let's say half of it is for blobs
302          */
303         heap += sizeof(struct blob) * nr_objects / 2;
304         /*
305          * and the other half is for trees (commits and tags are
306          * usually insignificant)
307          */
308         heap += sizeof(struct tree) * nr_objects / 2;
309         /* and then obj_hash[], underestimated in fact */
310         heap += sizeof(struct object *) * nr_objects;
311         /* revindex is used also */
312         heap += (sizeof(off_t) + sizeof(uint32_t)) * nr_objects;
313         /*
314          * read_sha1_file() (either at delta calculation phase, or
315          * writing phase) also fills up the delta base cache
316          */
317         heap += delta_base_cache_limit;
318         /* and of course pack-objects has its own delta cache */
319         heap += max_delta_cache_size;
320
321         return os_cache + heap;
322 }
323
324 static int keep_one_pack(struct string_list_item *item, void *data)
325 {
326         strvec_pushf(&repack, "--keep-pack=%s", basename(item->string));
327         return 0;
328 }
329
330 static void add_repack_all_option(struct string_list *keep_pack)
331 {
332         if (prune_expire && !strcmp(prune_expire, "now"))
333                 strvec_push(&repack, "-a");
334         else {
335                 strvec_push(&repack, "-A");
336                 if (prune_expire)
337                         strvec_pushf(&repack, "--unpack-unreachable=%s", prune_expire);
338         }
339
340         if (keep_pack)
341                 for_each_string_list(keep_pack, keep_one_pack, NULL);
342 }
343
344 static void add_repack_incremental_option(void)
345 {
346         strvec_push(&repack, "--no-write-bitmap-index");
347 }
348
349 static int need_to_gc(void)
350 {
351         /*
352          * Setting gc.auto to 0 or negative can disable the
353          * automatic gc.
354          */
355         if (gc_auto_threshold <= 0)
356                 return 0;
357
358         /*
359          * If there are too many loose objects, but not too many
360          * packs, we run "repack -d -l".  If there are too many packs,
361          * we run "repack -A -d -l".  Otherwise we tell the caller
362          * there is no need.
363          */
364         if (too_many_packs()) {
365                 struct string_list keep_pack = STRING_LIST_INIT_NODUP;
366
367                 if (big_pack_threshold) {
368                         find_base_packs(&keep_pack, big_pack_threshold);
369                         if (keep_pack.nr >= gc_auto_pack_limit) {
370                                 big_pack_threshold = 0;
371                                 string_list_clear(&keep_pack, 0);
372                                 find_base_packs(&keep_pack, 0);
373                         }
374                 } else {
375                         struct packed_git *p = find_base_packs(&keep_pack, 0);
376                         uint64_t mem_have, mem_want;
377
378                         mem_have = total_ram();
379                         mem_want = estimate_repack_memory(p);
380
381                         /*
382                          * Only allow 1/2 of memory for pack-objects, leave
383                          * the rest for the OS and other processes in the
384                          * system.
385                          */
386                         if (!mem_have || mem_want < mem_have / 2)
387                                 string_list_clear(&keep_pack, 0);
388                 }
389
390                 add_repack_all_option(&keep_pack);
391                 string_list_clear(&keep_pack, 0);
392         } else if (too_many_loose_objects())
393                 add_repack_incremental_option();
394         else
395                 return 0;
396
397         if (run_hook_le(NULL, "pre-auto-gc", NULL))
398                 return 0;
399         return 1;
400 }
401
402 /* return NULL on success, else hostname running the gc */
403 static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
404 {
405         struct lock_file lock = LOCK_INIT;
406         char my_host[HOST_NAME_MAX + 1];
407         struct strbuf sb = STRBUF_INIT;
408         struct stat st;
409         uintmax_t pid;
410         FILE *fp;
411         int fd;
412         char *pidfile_path;
413
414         if (is_tempfile_active(pidfile))
415                 /* already locked */
416                 return NULL;
417
418         if (xgethostname(my_host, sizeof(my_host)))
419                 xsnprintf(my_host, sizeof(my_host), "unknown");
420
421         pidfile_path = git_pathdup("gc.pid");
422         fd = hold_lock_file_for_update(&lock, pidfile_path,
423                                        LOCK_DIE_ON_ERROR);
424         if (!force) {
425                 static char locking_host[HOST_NAME_MAX + 1];
426                 static char *scan_fmt;
427                 int should_exit;
428
429                 if (!scan_fmt)
430                         scan_fmt = xstrfmt("%s %%%ds", "%"SCNuMAX, HOST_NAME_MAX);
431                 fp = fopen(pidfile_path, "r");
432                 memset(locking_host, 0, sizeof(locking_host));
433                 should_exit =
434                         fp != NULL &&
435                         !fstat(fileno(fp), &st) &&
436                         /*
437                          * 12 hour limit is very generous as gc should
438                          * never take that long. On the other hand we
439                          * don't really need a strict limit here,
440                          * running gc --auto one day late is not a big
441                          * problem. --force can be used in manual gc
442                          * after the user verifies that no gc is
443                          * running.
444                          */
445                         time(NULL) - st.st_mtime <= 12 * 3600 &&
446                         fscanf(fp, scan_fmt, &pid, locking_host) == 2 &&
447                         /* be gentle to concurrent "gc" on remote hosts */
448                         (strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM);
449                 if (fp != NULL)
450                         fclose(fp);
451                 if (should_exit) {
452                         if (fd >= 0)
453                                 rollback_lock_file(&lock);
454                         *ret_pid = pid;
455                         free(pidfile_path);
456                         return locking_host;
457                 }
458         }
459
460         strbuf_addf(&sb, "%"PRIuMAX" %s",
461                     (uintmax_t) getpid(), my_host);
462         write_in_full(fd, sb.buf, sb.len);
463         strbuf_release(&sb);
464         commit_lock_file(&lock);
465         pidfile = register_tempfile(pidfile_path);
466         free(pidfile_path);
467         return NULL;
468 }
469
470 /*
471  * Returns 0 if there was no previous error and gc can proceed, 1 if
472  * gc should not proceed due to an error in the last run. Prints a
473  * message and returns -1 if an error occurred while reading gc.log
474  */
475 static int report_last_gc_error(void)
476 {
477         struct strbuf sb = STRBUF_INIT;
478         int ret = 0;
479         ssize_t len;
480         struct stat st;
481         char *gc_log_path = git_pathdup("gc.log");
482
483         if (stat(gc_log_path, &st)) {
484                 if (errno == ENOENT)
485                         goto done;
486
487                 ret = error_errno(_("cannot stat '%s'"), gc_log_path);
488                 goto done;
489         }
490
491         if (st.st_mtime < gc_log_expire_time)
492                 goto done;
493
494         len = strbuf_read_file(&sb, gc_log_path, 0);
495         if (len < 0)
496                 ret = error_errno(_("cannot read '%s'"), gc_log_path);
497         else if (len > 0) {
498                 /*
499                  * A previous gc failed.  Report the error, and don't
500                  * bother with an automatic gc run since it is likely
501                  * to fail in the same way.
502                  */
503                 warning(_("The last gc run reported the following. "
504                                "Please correct the root cause\n"
505                                "and remove %s.\n"
506                                "Automatic cleanup will not be performed "
507                                "until the file is removed.\n\n"
508                                "%s"),
509                             gc_log_path, sb.buf);
510                 ret = 1;
511         }
512         strbuf_release(&sb);
513 done:
514         free(gc_log_path);
515         return ret;
516 }
517
518 static void gc_before_repack(void)
519 {
520         /*
521          * We may be called twice, as both the pre- and
522          * post-daemonized phases will call us, but running these
523          * commands more than once is pointless and wasteful.
524          */
525         static int done = 0;
526         if (done++)
527                 return;
528
529         if (pack_refs && maintenance_task_pack_refs(NULL))
530                 die(FAILED_RUN, "pack-refs");
531
532         if (prune_reflogs && run_command_v_opt(reflog.v, RUN_GIT_CMD))
533                 die(FAILED_RUN, reflog.v[0]);
534 }
535
536 int cmd_gc(int argc, const char **argv, const char *prefix)
537 {
538         int aggressive = 0;
539         int auto_gc = 0;
540         int quiet = 0;
541         int force = 0;
542         const char *name;
543         pid_t pid;
544         int daemonized = 0;
545         int keep_largest_pack = -1;
546         timestamp_t dummy;
547
548         struct option builtin_gc_options[] = {
549                 OPT__QUIET(&quiet, N_("suppress progress reporting")),
550                 { OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
551                         N_("prune unreferenced objects"),
552                         PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
553                 OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
554                 OPT_BOOL_F(0, "auto", &auto_gc, N_("enable auto-gc mode"),
555                            PARSE_OPT_NOCOMPLETE),
556                 OPT_BOOL_F(0, "force", &force,
557                            N_("force running gc even if there may be another gc running"),
558                            PARSE_OPT_NOCOMPLETE),
559                 OPT_BOOL(0, "keep-largest-pack", &keep_largest_pack,
560                          N_("repack all other packs except the largest pack")),
561                 OPT_END()
562         };
563
564         if (argc == 2 && !strcmp(argv[1], "-h"))
565                 usage_with_options(builtin_gc_usage, builtin_gc_options);
566
567         strvec_pushl(&reflog, "reflog", "expire", "--all", NULL);
568         strvec_pushl(&repack, "repack", "-d", "-l", NULL);
569         strvec_pushl(&prune, "prune", "--expire", NULL);
570         strvec_pushl(&prune_worktrees, "worktree", "prune", "--expire", NULL);
571         strvec_pushl(&rerere, "rerere", "gc", NULL);
572
573         /* default expiry time, overwritten in gc_config */
574         gc_config();
575         if (parse_expiry_date(gc_log_expire, &gc_log_expire_time))
576                 die(_("failed to parse gc.logexpiry value %s"), gc_log_expire);
577
578         if (pack_refs < 0)
579                 pack_refs = !is_bare_repository();
580
581         argc = parse_options(argc, argv, prefix, builtin_gc_options,
582                              builtin_gc_usage, 0);
583         if (argc > 0)
584                 usage_with_options(builtin_gc_usage, builtin_gc_options);
585
586         if (prune_expire && parse_expiry_date(prune_expire, &dummy))
587                 die(_("failed to parse prune expiry value %s"), prune_expire);
588
589         if (aggressive) {
590                 strvec_push(&repack, "-f");
591                 if (aggressive_depth > 0)
592                         strvec_pushf(&repack, "--depth=%d", aggressive_depth);
593                 if (aggressive_window > 0)
594                         strvec_pushf(&repack, "--window=%d", aggressive_window);
595         }
596         if (quiet)
597                 strvec_push(&repack, "-q");
598
599         if (auto_gc) {
600                 /*
601                  * Auto-gc should be least intrusive as possible.
602                  */
603                 if (!need_to_gc())
604                         return 0;
605                 if (!quiet) {
606                         if (detach_auto)
607                                 fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n"));
608                         else
609                                 fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
610                         fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n"));
611                 }
612                 if (detach_auto) {
613                         int ret = report_last_gc_error();
614                         if (ret < 0)
615                                 /* an I/O error occurred, already reported */
616                                 exit(128);
617                         if (ret == 1)
618                                 /* Last gc --auto failed. Skip this one. */
619                                 return 0;
620
621                         if (lock_repo_for_gc(force, &pid))
622                                 return 0;
623                         gc_before_repack(); /* dies on failure */
624                         delete_tempfile(&pidfile);
625
626                         /*
627                          * failure to daemonize is ok, we'll continue
628                          * in foreground
629                          */
630                         daemonized = !daemonize();
631                 }
632         } else {
633                 struct string_list keep_pack = STRING_LIST_INIT_NODUP;
634
635                 if (keep_largest_pack != -1) {
636                         if (keep_largest_pack)
637                                 find_base_packs(&keep_pack, 0);
638                 } else if (big_pack_threshold) {
639                         find_base_packs(&keep_pack, big_pack_threshold);
640                 }
641
642                 add_repack_all_option(&keep_pack);
643                 string_list_clear(&keep_pack, 0);
644         }
645
646         name = lock_repo_for_gc(force, &pid);
647         if (name) {
648                 if (auto_gc)
649                         return 0; /* be quiet on --auto */
650                 die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
651                     name, (uintmax_t)pid);
652         }
653
654         if (daemonized) {
655                 hold_lock_file_for_update(&log_lock,
656                                           git_path("gc.log"),
657                                           LOCK_DIE_ON_ERROR);
658                 dup2(get_lock_file_fd(&log_lock), 2);
659                 sigchain_push_common(process_log_file_on_signal);
660                 atexit(process_log_file_at_exit);
661         }
662
663         gc_before_repack();
664
665         if (!repository_format_precious_objects) {
666                 close_object_store(the_repository->objects);
667                 if (run_command_v_opt(repack.v, RUN_GIT_CMD))
668                         die(FAILED_RUN, repack.v[0]);
669
670                 if (prune_expire) {
671                         strvec_push(&prune, prune_expire);
672                         if (quiet)
673                                 strvec_push(&prune, "--no-progress");
674                         if (has_promisor_remote())
675                                 strvec_push(&prune,
676                                             "--exclude-promisor-objects");
677                         if (run_command_v_opt(prune.v, RUN_GIT_CMD))
678                                 die(FAILED_RUN, prune.v[0]);
679                 }
680         }
681
682         if (prune_worktrees_expire) {
683                 strvec_push(&prune_worktrees, prune_worktrees_expire);
684                 if (run_command_v_opt(prune_worktrees.v, RUN_GIT_CMD))
685                         die(FAILED_RUN, prune_worktrees.v[0]);
686         }
687
688         if (run_command_v_opt(rerere.v, RUN_GIT_CMD))
689                 die(FAILED_RUN, rerere.v[0]);
690
691         report_garbage = report_pack_garbage;
692         reprepare_packed_git(the_repository);
693         if (pack_garbage.nr > 0) {
694                 close_object_store(the_repository->objects);
695                 clean_pack_garbage();
696         }
697
698         prepare_repo_settings(the_repository);
699         if (the_repository->settings.gc_write_commit_graph == 1)
700                 write_commit_graph_reachable(the_repository->objects->odb,
701                                              !quiet && !daemonized ? COMMIT_GRAPH_WRITE_PROGRESS : 0,
702                                              NULL);
703
704         if (auto_gc && too_many_loose_objects())
705                 warning(_("There are too many unreachable loose objects; "
706                         "run 'git prune' to remove them."));
707
708         if (!daemonized)
709                 unlink(git_path("gc.log"));
710
711         return 0;
712 }
713
714 static const char *const builtin_maintenance_run_usage[] = {
715         N_("git maintenance run [--auto] [--[no-]quiet] [--task=<task>] [--schedule]"),
716         NULL
717 };
718
719 enum schedule_priority {
720         SCHEDULE_NONE = 0,
721         SCHEDULE_WEEKLY = 1,
722         SCHEDULE_DAILY = 2,
723         SCHEDULE_HOURLY = 3,
724 };
725
726 static enum schedule_priority parse_schedule(const char *value)
727 {
728         if (!value)
729                 return SCHEDULE_NONE;
730         if (!strcasecmp(value, "hourly"))
731                 return SCHEDULE_HOURLY;
732         if (!strcasecmp(value, "daily"))
733                 return SCHEDULE_DAILY;
734         if (!strcasecmp(value, "weekly"))
735                 return SCHEDULE_WEEKLY;
736         return SCHEDULE_NONE;
737 }
738
739 static int maintenance_opt_schedule(const struct option *opt, const char *arg,
740                                     int unset)
741 {
742         enum schedule_priority *priority = opt->value;
743
744         if (unset)
745                 die(_("--no-schedule is not allowed"));
746
747         *priority = parse_schedule(arg);
748
749         if (!*priority)
750                 die(_("unrecognized --schedule argument '%s'"), arg);
751
752         return 0;
753 }
754
755 struct maintenance_run_opts {
756         int auto_flag;
757         int quiet;
758         enum schedule_priority schedule;
759 };
760
761 /* Remember to update object flag allocation in object.h */
762 #define SEEN            (1u<<0)
763
764 struct cg_auto_data {
765         int num_not_in_graph;
766         int limit;
767 };
768
769 static int dfs_on_ref(const char *refname,
770                       const struct object_id *oid, int flags,
771                       void *cb_data)
772 {
773         struct cg_auto_data *data = (struct cg_auto_data *)cb_data;
774         int result = 0;
775         struct object_id peeled;
776         struct commit_list *stack = NULL;
777         struct commit *commit;
778
779         if (!peel_iterated_oid(oid, &peeled))
780                 oid = &peeled;
781         if (oid_object_info(the_repository, oid, NULL) != OBJ_COMMIT)
782                 return 0;
783
784         commit = lookup_commit(the_repository, oid);
785         if (!commit)
786                 return 0;
787         if (parse_commit(commit) ||
788             commit_graph_position(commit) != COMMIT_NOT_FROM_GRAPH)
789                 return 0;
790
791         data->num_not_in_graph++;
792
793         if (data->num_not_in_graph >= data->limit)
794                 return 1;
795
796         commit_list_append(commit, &stack);
797
798         while (!result && stack) {
799                 struct commit_list *parent;
800
801                 commit = pop_commit(&stack);
802
803                 for (parent = commit->parents; parent; parent = parent->next) {
804                         if (parse_commit(parent->item) ||
805                             commit_graph_position(parent->item) != COMMIT_NOT_FROM_GRAPH ||
806                             parent->item->object.flags & SEEN)
807                                 continue;
808
809                         parent->item->object.flags |= SEEN;
810                         data->num_not_in_graph++;
811
812                         if (data->num_not_in_graph >= data->limit) {
813                                 result = 1;
814                                 break;
815                         }
816
817                         commit_list_append(parent->item, &stack);
818                 }
819         }
820
821         free_commit_list(stack);
822         return result;
823 }
824
825 static int should_write_commit_graph(void)
826 {
827         int result;
828         struct cg_auto_data data;
829
830         data.num_not_in_graph = 0;
831         data.limit = 100;
832         git_config_get_int("maintenance.commit-graph.auto",
833                            &data.limit);
834
835         if (!data.limit)
836                 return 0;
837         if (data.limit < 0)
838                 return 1;
839
840         result = for_each_ref(dfs_on_ref, &data);
841
842         repo_clear_commit_marks(the_repository, SEEN);
843
844         return result;
845 }
846
847 static int run_write_commit_graph(struct maintenance_run_opts *opts)
848 {
849         struct child_process child = CHILD_PROCESS_INIT;
850
851         child.git_cmd = 1;
852         strvec_pushl(&child.args, "commit-graph", "write",
853                      "--split", "--reachable", NULL);
854
855         if (opts->quiet)
856                 strvec_push(&child.args, "--no-progress");
857
858         return !!run_command(&child);
859 }
860
861 static int maintenance_task_commit_graph(struct maintenance_run_opts *opts)
862 {
863         prepare_repo_settings(the_repository);
864         if (!the_repository->settings.core_commit_graph)
865                 return 0;
866
867         close_object_store(the_repository->objects);
868         if (run_write_commit_graph(opts)) {
869                 error(_("failed to write commit-graph"));
870                 return 1;
871         }
872
873         return 0;
874 }
875
876 static int fetch_remote(struct remote *remote, void *cbdata)
877 {
878         struct maintenance_run_opts *opts = cbdata;
879         struct child_process child = CHILD_PROCESS_INIT;
880
881         child.git_cmd = 1;
882         strvec_pushl(&child.args, "fetch", remote->name,
883                      "--prefetch", "--prune", "--no-tags",
884                      "--no-write-fetch-head", "--recurse-submodules=no",
885                      NULL);
886
887         if (opts->quiet)
888                 strvec_push(&child.args, "--quiet");
889
890         return !!run_command(&child);
891 }
892
893 static int maintenance_task_prefetch(struct maintenance_run_opts *opts)
894 {
895         git_config_set_multivar_gently("log.excludedecoration",
896                                         "refs/prefetch/",
897                                         "refs/prefetch/",
898                                         CONFIG_FLAGS_FIXED_VALUE |
899                                         CONFIG_FLAGS_MULTI_REPLACE);
900
901         if (for_each_remote(fetch_remote, opts)) {
902                 error(_("failed to prefetch remotes"));
903                 return 1;
904         }
905
906         return 0;
907 }
908
909 static int maintenance_task_gc(struct maintenance_run_opts *opts)
910 {
911         struct child_process child = CHILD_PROCESS_INIT;
912
913         child.git_cmd = 1;
914         strvec_push(&child.args, "gc");
915
916         if (opts->auto_flag)
917                 strvec_push(&child.args, "--auto");
918         if (opts->quiet)
919                 strvec_push(&child.args, "--quiet");
920         else
921                 strvec_push(&child.args, "--no-quiet");
922
923         close_object_store(the_repository->objects);
924         return run_command(&child);
925 }
926
927 static int prune_packed(struct maintenance_run_opts *opts)
928 {
929         struct child_process child = CHILD_PROCESS_INIT;
930
931         child.git_cmd = 1;
932         strvec_push(&child.args, "prune-packed");
933
934         if (opts->quiet)
935                 strvec_push(&child.args, "--quiet");
936
937         return !!run_command(&child);
938 }
939
940 struct write_loose_object_data {
941         FILE *in;
942         int count;
943         int batch_size;
944 };
945
946 static int loose_object_auto_limit = 100;
947
948 static int loose_object_count(const struct object_id *oid,
949                                const char *path,
950                                void *data)
951 {
952         int *count = (int*)data;
953         if (++(*count) >= loose_object_auto_limit)
954                 return 1;
955         return 0;
956 }
957
958 static int loose_object_auto_condition(void)
959 {
960         int count = 0;
961
962         git_config_get_int("maintenance.loose-objects.auto",
963                            &loose_object_auto_limit);
964
965         if (!loose_object_auto_limit)
966                 return 0;
967         if (loose_object_auto_limit < 0)
968                 return 1;
969
970         return for_each_loose_file_in_objdir(the_repository->objects->odb->path,
971                                              loose_object_count,
972                                              NULL, NULL, &count);
973 }
974
975 static int bail_on_loose(const struct object_id *oid,
976                          const char *path,
977                          void *data)
978 {
979         return 1;
980 }
981
982 static int write_loose_object_to_stdin(const struct object_id *oid,
983                                        const char *path,
984                                        void *data)
985 {
986         struct write_loose_object_data *d = (struct write_loose_object_data *)data;
987
988         fprintf(d->in, "%s\n", oid_to_hex(oid));
989
990         return ++(d->count) > d->batch_size;
991 }
992
993 static int pack_loose(struct maintenance_run_opts *opts)
994 {
995         struct repository *r = the_repository;
996         int result = 0;
997         struct write_loose_object_data data;
998         struct child_process pack_proc = CHILD_PROCESS_INIT;
999
1000         /*
1001          * Do not start pack-objects process
1002          * if there are no loose objects.
1003          */
1004         if (!for_each_loose_file_in_objdir(r->objects->odb->path,
1005                                            bail_on_loose,
1006                                            NULL, NULL, NULL))
1007                 return 0;
1008
1009         pack_proc.git_cmd = 1;
1010
1011         strvec_push(&pack_proc.args, "pack-objects");
1012         if (opts->quiet)
1013                 strvec_push(&pack_proc.args, "--quiet");
1014         strvec_pushf(&pack_proc.args, "%s/pack/loose", r->objects->odb->path);
1015
1016         pack_proc.in = -1;
1017
1018         if (start_command(&pack_proc)) {
1019                 error(_("failed to start 'git pack-objects' process"));
1020                 return 1;
1021         }
1022
1023         data.in = xfdopen(pack_proc.in, "w");
1024         data.count = 0;
1025         data.batch_size = 50000;
1026
1027         for_each_loose_file_in_objdir(r->objects->odb->path,
1028                                       write_loose_object_to_stdin,
1029                                       NULL,
1030                                       NULL,
1031                                       &data);
1032
1033         fclose(data.in);
1034
1035         if (finish_command(&pack_proc)) {
1036                 error(_("failed to finish 'git pack-objects' process"));
1037                 result = 1;
1038         }
1039
1040         return result;
1041 }
1042
1043 static int maintenance_task_loose_objects(struct maintenance_run_opts *opts)
1044 {
1045         return prune_packed(opts) || pack_loose(opts);
1046 }
1047
1048 static int incremental_repack_auto_condition(void)
1049 {
1050         struct packed_git *p;
1051         int enabled;
1052         int incremental_repack_auto_limit = 10;
1053         int count = 0;
1054
1055         if (git_config_get_bool("core.multiPackIndex", &enabled) ||
1056             !enabled)
1057                 return 0;
1058
1059         git_config_get_int("maintenance.incremental-repack.auto",
1060                            &incremental_repack_auto_limit);
1061
1062         if (!incremental_repack_auto_limit)
1063                 return 0;
1064         if (incremental_repack_auto_limit < 0)
1065                 return 1;
1066
1067         for (p = get_packed_git(the_repository);
1068              count < incremental_repack_auto_limit && p;
1069              p = p->next) {
1070                 if (!p->multi_pack_index)
1071                         count++;
1072         }
1073
1074         return count >= incremental_repack_auto_limit;
1075 }
1076
1077 static int multi_pack_index_write(struct maintenance_run_opts *opts)
1078 {
1079         struct child_process child = CHILD_PROCESS_INIT;
1080
1081         child.git_cmd = 1;
1082         strvec_pushl(&child.args, "multi-pack-index", "write", NULL);
1083
1084         if (opts->quiet)
1085                 strvec_push(&child.args, "--no-progress");
1086
1087         if (run_command(&child))
1088                 return error(_("failed to write multi-pack-index"));
1089
1090         return 0;
1091 }
1092
1093 static int multi_pack_index_expire(struct maintenance_run_opts *opts)
1094 {
1095         struct child_process child = CHILD_PROCESS_INIT;
1096
1097         child.git_cmd = 1;
1098         strvec_pushl(&child.args, "multi-pack-index", "expire", NULL);
1099
1100         if (opts->quiet)
1101                 strvec_push(&child.args, "--no-progress");
1102
1103         close_object_store(the_repository->objects);
1104
1105         if (run_command(&child))
1106                 return error(_("'git multi-pack-index expire' failed"));
1107
1108         return 0;
1109 }
1110
1111 #define TWO_GIGABYTES (INT32_MAX)
1112
1113 static off_t get_auto_pack_size(void)
1114 {
1115         /*
1116          * The "auto" value is special: we optimize for
1117          * one large pack-file (i.e. from a clone) and
1118          * expect the rest to be small and they can be
1119          * repacked quickly.
1120          *
1121          * The strategy we select here is to select a
1122          * size that is one more than the second largest
1123          * pack-file. This ensures that we will repack
1124          * at least two packs if there are three or more
1125          * packs.
1126          */
1127         off_t max_size = 0;
1128         off_t second_largest_size = 0;
1129         off_t result_size;
1130         struct packed_git *p;
1131         struct repository *r = the_repository;
1132
1133         reprepare_packed_git(r);
1134         for (p = get_all_packs(r); p; p = p->next) {
1135                 if (p->pack_size > max_size) {
1136                         second_largest_size = max_size;
1137                         max_size = p->pack_size;
1138                 } else if (p->pack_size > second_largest_size)
1139                         second_largest_size = p->pack_size;
1140         }
1141
1142         result_size = second_largest_size + 1;
1143
1144         /* But limit ourselves to a batch size of 2g */
1145         if (result_size > TWO_GIGABYTES)
1146                 result_size = TWO_GIGABYTES;
1147
1148         return result_size;
1149 }
1150
1151 static int multi_pack_index_repack(struct maintenance_run_opts *opts)
1152 {
1153         struct child_process child = CHILD_PROCESS_INIT;
1154
1155         child.git_cmd = 1;
1156         strvec_pushl(&child.args, "multi-pack-index", "repack", NULL);
1157
1158         if (opts->quiet)
1159                 strvec_push(&child.args, "--no-progress");
1160
1161         strvec_pushf(&child.args, "--batch-size=%"PRIuMAX,
1162                                   (uintmax_t)get_auto_pack_size());
1163
1164         close_object_store(the_repository->objects);
1165
1166         if (run_command(&child))
1167                 return error(_("'git multi-pack-index repack' failed"));
1168
1169         return 0;
1170 }
1171
1172 static int maintenance_task_incremental_repack(struct maintenance_run_opts *opts)
1173 {
1174         prepare_repo_settings(the_repository);
1175         if (!the_repository->settings.core_multi_pack_index) {
1176                 warning(_("skipping incremental-repack task because core.multiPackIndex is disabled"));
1177                 return 0;
1178         }
1179
1180         if (multi_pack_index_write(opts))
1181                 return 1;
1182         if (multi_pack_index_expire(opts))
1183                 return 1;
1184         if (multi_pack_index_repack(opts))
1185                 return 1;
1186         return 0;
1187 }
1188
1189 typedef int maintenance_task_fn(struct maintenance_run_opts *opts);
1190
1191 /*
1192  * An auto condition function returns 1 if the task should run
1193  * and 0 if the task should NOT run. See needs_to_gc() for an
1194  * example.
1195  */
1196 typedef int maintenance_auto_fn(void);
1197
1198 struct maintenance_task {
1199         const char *name;
1200         maintenance_task_fn *fn;
1201         maintenance_auto_fn *auto_condition;
1202         unsigned enabled:1;
1203
1204         enum schedule_priority schedule;
1205
1206         /* -1 if not selected. */
1207         int selected_order;
1208 };
1209
1210 enum maintenance_task_label {
1211         TASK_PREFETCH,
1212         TASK_LOOSE_OBJECTS,
1213         TASK_INCREMENTAL_REPACK,
1214         TASK_GC,
1215         TASK_COMMIT_GRAPH,
1216         TASK_PACK_REFS,
1217
1218         /* Leave as final value */
1219         TASK__COUNT
1220 };
1221
1222 static struct maintenance_task tasks[] = {
1223         [TASK_PREFETCH] = {
1224                 "prefetch",
1225                 maintenance_task_prefetch,
1226         },
1227         [TASK_LOOSE_OBJECTS] = {
1228                 "loose-objects",
1229                 maintenance_task_loose_objects,
1230                 loose_object_auto_condition,
1231         },
1232         [TASK_INCREMENTAL_REPACK] = {
1233                 "incremental-repack",
1234                 maintenance_task_incremental_repack,
1235                 incremental_repack_auto_condition,
1236         },
1237         [TASK_GC] = {
1238                 "gc",
1239                 maintenance_task_gc,
1240                 need_to_gc,
1241                 1,
1242         },
1243         [TASK_COMMIT_GRAPH] = {
1244                 "commit-graph",
1245                 maintenance_task_commit_graph,
1246                 should_write_commit_graph,
1247         },
1248         [TASK_PACK_REFS] = {
1249                 "pack-refs",
1250                 maintenance_task_pack_refs,
1251                 NULL,
1252         },
1253 };
1254
1255 static int compare_tasks_by_selection(const void *a_, const void *b_)
1256 {
1257         const struct maintenance_task *a = a_;
1258         const struct maintenance_task *b = b_;
1259
1260         return b->selected_order - a->selected_order;
1261 }
1262
1263 static int maintenance_run_tasks(struct maintenance_run_opts *opts)
1264 {
1265         int i, found_selected = 0;
1266         int result = 0;
1267         struct lock_file lk;
1268         struct repository *r = the_repository;
1269         char *lock_path = xstrfmt("%s/maintenance", r->objects->odb->path);
1270
1271         if (hold_lock_file_for_update(&lk, lock_path, LOCK_NO_DEREF) < 0) {
1272                 /*
1273                  * Another maintenance command is running.
1274                  *
1275                  * If --auto was provided, then it is likely due to a
1276                  * recursive process stack. Do not report an error in
1277                  * that case.
1278                  */
1279                 if (!opts->auto_flag && !opts->quiet)
1280                         warning(_("lock file '%s' exists, skipping maintenance"),
1281                                 lock_path);
1282                 free(lock_path);
1283                 return 0;
1284         }
1285         free(lock_path);
1286
1287         for (i = 0; !found_selected && i < TASK__COUNT; i++)
1288                 found_selected = tasks[i].selected_order >= 0;
1289
1290         if (found_selected)
1291                 QSORT(tasks, TASK__COUNT, compare_tasks_by_selection);
1292
1293         for (i = 0; i < TASK__COUNT; i++) {
1294                 if (found_selected && tasks[i].selected_order < 0)
1295                         continue;
1296
1297                 if (!found_selected && !tasks[i].enabled)
1298                         continue;
1299
1300                 if (opts->auto_flag &&
1301                     (!tasks[i].auto_condition ||
1302                      !tasks[i].auto_condition()))
1303                         continue;
1304
1305                 if (opts->schedule && tasks[i].schedule < opts->schedule)
1306                         continue;
1307
1308                 trace2_region_enter("maintenance", tasks[i].name, r);
1309                 if (tasks[i].fn(opts)) {
1310                         error(_("task '%s' failed"), tasks[i].name);
1311                         result = 1;
1312                 }
1313                 trace2_region_leave("maintenance", tasks[i].name, r);
1314         }
1315
1316         rollback_lock_file(&lk);
1317         return result;
1318 }
1319
1320 static void initialize_maintenance_strategy(void)
1321 {
1322         char *config_str;
1323
1324         if (git_config_get_string("maintenance.strategy", &config_str))
1325                 return;
1326
1327         if (!strcasecmp(config_str, "incremental")) {
1328                 tasks[TASK_GC].schedule = SCHEDULE_NONE;
1329                 tasks[TASK_COMMIT_GRAPH].enabled = 1;
1330                 tasks[TASK_COMMIT_GRAPH].schedule = SCHEDULE_HOURLY;
1331                 tasks[TASK_PREFETCH].enabled = 1;
1332                 tasks[TASK_PREFETCH].schedule = SCHEDULE_HOURLY;
1333                 tasks[TASK_INCREMENTAL_REPACK].enabled = 1;
1334                 tasks[TASK_INCREMENTAL_REPACK].schedule = SCHEDULE_DAILY;
1335                 tasks[TASK_LOOSE_OBJECTS].enabled = 1;
1336                 tasks[TASK_LOOSE_OBJECTS].schedule = SCHEDULE_DAILY;
1337                 tasks[TASK_PACK_REFS].enabled = 1;
1338                 tasks[TASK_PACK_REFS].schedule = SCHEDULE_WEEKLY;
1339         }
1340 }
1341
1342 static void initialize_task_config(int schedule)
1343 {
1344         int i;
1345         struct strbuf config_name = STRBUF_INIT;
1346         gc_config();
1347
1348         if (schedule)
1349                 initialize_maintenance_strategy();
1350
1351         for (i = 0; i < TASK__COUNT; i++) {
1352                 int config_value;
1353                 char *config_str;
1354
1355                 strbuf_reset(&config_name);
1356                 strbuf_addf(&config_name, "maintenance.%s.enabled",
1357                             tasks[i].name);
1358
1359                 if (!git_config_get_bool(config_name.buf, &config_value))
1360                         tasks[i].enabled = config_value;
1361
1362                 strbuf_reset(&config_name);
1363                 strbuf_addf(&config_name, "maintenance.%s.schedule",
1364                             tasks[i].name);
1365
1366                 if (!git_config_get_string(config_name.buf, &config_str)) {
1367                         tasks[i].schedule = parse_schedule(config_str);
1368                         free(config_str);
1369                 }
1370         }
1371
1372         strbuf_release(&config_name);
1373 }
1374
1375 static int task_option_parse(const struct option *opt,
1376                              const char *arg, int unset)
1377 {
1378         int i, num_selected = 0;
1379         struct maintenance_task *task = NULL;
1380
1381         BUG_ON_OPT_NEG(unset);
1382
1383         for (i = 0; i < TASK__COUNT; i++) {
1384                 if (tasks[i].selected_order >= 0)
1385                         num_selected++;
1386                 if (!strcasecmp(tasks[i].name, arg)) {
1387                         task = &tasks[i];
1388                 }
1389         }
1390
1391         if (!task) {
1392                 error(_("'%s' is not a valid task"), arg);
1393                 return 1;
1394         }
1395
1396         if (task->selected_order >= 0) {
1397                 error(_("task '%s' cannot be selected multiple times"), arg);
1398                 return 1;
1399         }
1400
1401         task->selected_order = num_selected + 1;
1402
1403         return 0;
1404 }
1405
1406 static int maintenance_run(int argc, const char **argv, const char *prefix)
1407 {
1408         int i;
1409         struct maintenance_run_opts opts;
1410         struct option builtin_maintenance_run_options[] = {
1411                 OPT_BOOL(0, "auto", &opts.auto_flag,
1412                          N_("run tasks based on the state of the repository")),
1413                 OPT_CALLBACK(0, "schedule", &opts.schedule, N_("frequency"),
1414                              N_("run tasks based on frequency"),
1415                              maintenance_opt_schedule),
1416                 OPT_BOOL(0, "quiet", &opts.quiet,
1417                          N_("do not report progress or other information over stderr")),
1418                 OPT_CALLBACK_F(0, "task", NULL, N_("task"),
1419                         N_("run a specific task"),
1420                         PARSE_OPT_NONEG, task_option_parse),
1421                 OPT_END()
1422         };
1423         memset(&opts, 0, sizeof(opts));
1424
1425         opts.quiet = !isatty(2);
1426
1427         for (i = 0; i < TASK__COUNT; i++)
1428                 tasks[i].selected_order = -1;
1429
1430         argc = parse_options(argc, argv, prefix,
1431                              builtin_maintenance_run_options,
1432                              builtin_maintenance_run_usage,
1433                              PARSE_OPT_STOP_AT_NON_OPTION);
1434
1435         if (opts.auto_flag && opts.schedule)
1436                 die(_("use at most one of --auto and --schedule=<frequency>"));
1437
1438         initialize_task_config(opts.schedule);
1439
1440         if (argc != 0)
1441                 usage_with_options(builtin_maintenance_run_usage,
1442                                    builtin_maintenance_run_options);
1443         return maintenance_run_tasks(&opts);
1444 }
1445
1446 static char *get_maintpath(void)
1447 {
1448         struct strbuf sb = STRBUF_INIT;
1449         const char *p = the_repository->worktree ?
1450                 the_repository->worktree : the_repository->gitdir;
1451
1452         strbuf_realpath(&sb, p, 1);
1453         return strbuf_detach(&sb, NULL);
1454 }
1455
1456 static int maintenance_register(void)
1457 {
1458         int rc;
1459         char *config_value;
1460         struct child_process config_set = CHILD_PROCESS_INIT;
1461         struct child_process config_get = CHILD_PROCESS_INIT;
1462         char *maintpath = get_maintpath();
1463
1464         /* Disable foreground maintenance */
1465         git_config_set("maintenance.auto", "false");
1466
1467         /* Set maintenance strategy, if unset */
1468         if (!git_config_get_string("maintenance.strategy", &config_value))
1469                 free(config_value);
1470         else
1471                 git_config_set("maintenance.strategy", "incremental");
1472
1473         config_get.git_cmd = 1;
1474         strvec_pushl(&config_get.args, "config", "--global", "--get",
1475                      "--fixed-value", "maintenance.repo", maintpath, NULL);
1476         config_get.out = -1;
1477
1478         if (start_command(&config_get)) {
1479                 rc = error(_("failed to run 'git config'"));
1480                 goto done;
1481         }
1482
1483         /* We already have this value in our config! */
1484         if (!finish_command(&config_get)) {
1485                 rc = 0;
1486                 goto done;
1487         }
1488
1489         config_set.git_cmd = 1;
1490         strvec_pushl(&config_set.args, "config", "--add", "--global", "maintenance.repo",
1491                      maintpath, NULL);
1492
1493         rc = run_command(&config_set);
1494
1495 done:
1496         free(maintpath);
1497         return rc;
1498 }
1499
1500 static int maintenance_unregister(void)
1501 {
1502         int rc;
1503         struct child_process config_unset = CHILD_PROCESS_INIT;
1504         char *maintpath = get_maintpath();
1505
1506         config_unset.git_cmd = 1;
1507         strvec_pushl(&config_unset.args, "config", "--global", "--unset",
1508                      "--fixed-value", "maintenance.repo", maintpath, NULL);
1509
1510         rc = run_command(&config_unset);
1511         free(maintpath);
1512         return rc;
1513 }
1514
1515 static const char *get_frequency(enum schedule_priority schedule)
1516 {
1517         switch (schedule) {
1518         case SCHEDULE_HOURLY:
1519                 return "hourly";
1520         case SCHEDULE_DAILY:
1521                 return "daily";
1522         case SCHEDULE_WEEKLY:
1523                 return "weekly";
1524         default:
1525                 BUG("invalid schedule %d", schedule);
1526         }
1527 }
1528
1529 static char *launchctl_service_name(const char *frequency)
1530 {
1531         struct strbuf label = STRBUF_INIT;
1532         strbuf_addf(&label, "org.git-scm.git.%s", frequency);
1533         return strbuf_detach(&label, NULL);
1534 }
1535
1536 static char *launchctl_service_filename(const char *name)
1537 {
1538         char *expanded;
1539         struct strbuf filename = STRBUF_INIT;
1540         strbuf_addf(&filename, "~/Library/LaunchAgents/%s.plist", name);
1541
1542         expanded = expand_user_path(filename.buf, 1);
1543         if (!expanded)
1544                 die(_("failed to expand path '%s'"), filename.buf);
1545
1546         strbuf_release(&filename);
1547         return expanded;
1548 }
1549
1550 static char *launchctl_get_uid(void)
1551 {
1552         return xstrfmt("gui/%d", getuid());
1553 }
1554
1555 static int launchctl_boot_plist(int enable, const char *filename, const char *cmd)
1556 {
1557         int result;
1558         struct child_process child = CHILD_PROCESS_INIT;
1559         char *uid = launchctl_get_uid();
1560
1561         strvec_split(&child.args, cmd);
1562         if (enable)
1563                 strvec_push(&child.args, "bootstrap");
1564         else
1565                 strvec_push(&child.args, "bootout");
1566         strvec_push(&child.args, uid);
1567         strvec_push(&child.args, filename);
1568
1569         child.no_stderr = 1;
1570         child.no_stdout = 1;
1571
1572         if (start_command(&child))
1573                 die(_("failed to start launchctl"));
1574
1575         result = finish_command(&child);
1576
1577         free(uid);
1578         return result;
1579 }
1580
1581 static int launchctl_remove_plist(enum schedule_priority schedule, const char *cmd)
1582 {
1583         const char *frequency = get_frequency(schedule);
1584         char *name = launchctl_service_name(frequency);
1585         char *filename = launchctl_service_filename(name);
1586         int result = launchctl_boot_plist(0, filename, cmd);
1587         unlink(filename);
1588         free(filename);
1589         free(name);
1590         return result;
1591 }
1592
1593 static int launchctl_remove_plists(const char *cmd)
1594 {
1595         return launchctl_remove_plist(SCHEDULE_HOURLY, cmd) ||
1596                 launchctl_remove_plist(SCHEDULE_DAILY, cmd) ||
1597                 launchctl_remove_plist(SCHEDULE_WEEKLY, cmd);
1598 }
1599
1600 static int launchctl_schedule_plist(const char *exec_path, enum schedule_priority schedule, const char *cmd)
1601 {
1602         FILE *plist;
1603         int i;
1604         const char *preamble, *repeat;
1605         const char *frequency = get_frequency(schedule);
1606         char *name = launchctl_service_name(frequency);
1607         char *filename = launchctl_service_filename(name);
1608
1609         if (safe_create_leading_directories(filename))
1610                 die(_("failed to create directories for '%s'"), filename);
1611         plist = xfopen(filename, "w");
1612
1613         preamble = "<?xml version=\"1.0\"?>\n"
1614                    "<!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">\n"
1615                    "<plist version=\"1.0\">"
1616                    "<dict>\n"
1617                    "<key>Label</key><string>%s</string>\n"
1618                    "<key>ProgramArguments</key>\n"
1619                    "<array>\n"
1620                    "<string>%s/git</string>\n"
1621                    "<string>--exec-path=%s</string>\n"
1622                    "<string>for-each-repo</string>\n"
1623                    "<string>--config=maintenance.repo</string>\n"
1624                    "<string>maintenance</string>\n"
1625                    "<string>run</string>\n"
1626                    "<string>--schedule=%s</string>\n"
1627                    "</array>\n"
1628                    "<key>StartCalendarInterval</key>\n"
1629                    "<array>\n";
1630         fprintf(plist, preamble, name, exec_path, exec_path, frequency);
1631
1632         switch (schedule) {
1633         case SCHEDULE_HOURLY:
1634                 repeat = "<dict>\n"
1635                          "<key>Hour</key><integer>%d</integer>\n"
1636                          "<key>Minute</key><integer>0</integer>\n"
1637                          "</dict>\n";
1638                 for (i = 1; i <= 23; i++)
1639                         fprintf(plist, repeat, i);
1640                 break;
1641
1642         case SCHEDULE_DAILY:
1643                 repeat = "<dict>\n"
1644                          "<key>Day</key><integer>%d</integer>\n"
1645                          "<key>Hour</key><integer>0</integer>\n"
1646                          "<key>Minute</key><integer>0</integer>\n"
1647                          "</dict>\n";
1648                 for (i = 1; i <= 6; i++)
1649                         fprintf(plist, repeat, i);
1650                 break;
1651
1652         case SCHEDULE_WEEKLY:
1653                 fprintf(plist,
1654                         "<dict>\n"
1655                         "<key>Day</key><integer>0</integer>\n"
1656                         "<key>Hour</key><integer>0</integer>\n"
1657                         "<key>Minute</key><integer>0</integer>\n"
1658                         "</dict>\n");
1659                 break;
1660
1661         default:
1662                 /* unreachable */
1663                 break;
1664         }
1665         fprintf(plist, "</array>\n</dict>\n</plist>\n");
1666         fclose(plist);
1667
1668         /* bootout might fail if not already running, so ignore */
1669         launchctl_boot_plist(0, filename, cmd);
1670         if (launchctl_boot_plist(1, filename, cmd))
1671                 die(_("failed to bootstrap service %s"), filename);
1672
1673         free(filename);
1674         free(name);
1675         return 0;
1676 }
1677
1678 static int launchctl_add_plists(const char *cmd)
1679 {
1680         const char *exec_path = git_exec_path();
1681
1682         return launchctl_schedule_plist(exec_path, SCHEDULE_HOURLY, cmd) ||
1683                 launchctl_schedule_plist(exec_path, SCHEDULE_DAILY, cmd) ||
1684                 launchctl_schedule_plist(exec_path, SCHEDULE_WEEKLY, cmd);
1685 }
1686
1687 static int launchctl_update_schedule(int run_maintenance, int fd, const char *cmd)
1688 {
1689         if (run_maintenance)
1690                 return launchctl_add_plists(cmd);
1691         else
1692                 return launchctl_remove_plists(cmd);
1693 }
1694
1695 static char *schtasks_task_name(const char *frequency)
1696 {
1697         struct strbuf label = STRBUF_INIT;
1698         strbuf_addf(&label, "Git Maintenance (%s)", frequency);
1699         return strbuf_detach(&label, NULL);
1700 }
1701
1702 static int schtasks_remove_task(enum schedule_priority schedule, const char *cmd)
1703 {
1704         int result;
1705         struct strvec args = STRVEC_INIT;
1706         const char *frequency = get_frequency(schedule);
1707         char *name = schtasks_task_name(frequency);
1708
1709         strvec_split(&args, cmd);
1710         strvec_pushl(&args, "/delete", "/tn", name, "/f", NULL);
1711
1712         result = run_command_v_opt(args.v, 0);
1713
1714         strvec_clear(&args);
1715         free(name);
1716         return result;
1717 }
1718
1719 static int schtasks_remove_tasks(const char *cmd)
1720 {
1721         return schtasks_remove_task(SCHEDULE_HOURLY, cmd) ||
1722                 schtasks_remove_task(SCHEDULE_DAILY, cmd) ||
1723                 schtasks_remove_task(SCHEDULE_WEEKLY, cmd);
1724 }
1725
1726 static int schtasks_schedule_task(const char *exec_path, enum schedule_priority schedule, const char *cmd)
1727 {
1728         int result;
1729         struct child_process child = CHILD_PROCESS_INIT;
1730         const char *xml;
1731         struct tempfile *tfile;
1732         const char *frequency = get_frequency(schedule);
1733         char *name = schtasks_task_name(frequency);
1734         struct strbuf tfilename = STRBUF_INIT;
1735
1736         strbuf_addf(&tfilename, "%s/schedule_%s_XXXXXX",
1737                     get_git_common_dir(), frequency);
1738         tfile = xmks_tempfile(tfilename.buf);
1739         strbuf_release(&tfilename);
1740
1741         if (!fdopen_tempfile(tfile, "w"))
1742                 die(_("failed to create temp xml file"));
1743
1744         xml = "<?xml version=\"1.0\" ?>\n"
1745               "<Task version=\"1.4\" xmlns=\"http://schemas.microsoft.com/windows/2004/02/mit/task\">\n"
1746               "<Triggers>\n"
1747               "<CalendarTrigger>\n";
1748         fputs(xml, tfile->fp);
1749
1750         switch (schedule) {
1751         case SCHEDULE_HOURLY:
1752                 fprintf(tfile->fp,
1753                         "<StartBoundary>2020-01-01T01:00:00</StartBoundary>\n"
1754                         "<Enabled>true</Enabled>\n"
1755                         "<ScheduleByDay>\n"
1756                         "<DaysInterval>1</DaysInterval>\n"
1757                         "</ScheduleByDay>\n"
1758                         "<Repetition>\n"
1759                         "<Interval>PT1H</Interval>\n"
1760                         "<Duration>PT23H</Duration>\n"
1761                         "<StopAtDurationEnd>false</StopAtDurationEnd>\n"
1762                         "</Repetition>\n");
1763                 break;
1764
1765         case SCHEDULE_DAILY:
1766                 fprintf(tfile->fp,
1767                         "<StartBoundary>2020-01-01T00:00:00</StartBoundary>\n"
1768                         "<Enabled>true</Enabled>\n"
1769                         "<ScheduleByWeek>\n"
1770                         "<DaysOfWeek>\n"
1771                         "<Monday />\n"
1772                         "<Tuesday />\n"
1773                         "<Wednesday />\n"
1774                         "<Thursday />\n"
1775                         "<Friday />\n"
1776                         "<Saturday />\n"
1777                         "</DaysOfWeek>\n"
1778                         "<WeeksInterval>1</WeeksInterval>\n"
1779                         "</ScheduleByWeek>\n");
1780                 break;
1781
1782         case SCHEDULE_WEEKLY:
1783                 fprintf(tfile->fp,
1784                         "<StartBoundary>2020-01-01T00:00:00</StartBoundary>\n"
1785                         "<Enabled>true</Enabled>\n"
1786                         "<ScheduleByWeek>\n"
1787                         "<DaysOfWeek>\n"
1788                         "<Sunday />\n"
1789                         "</DaysOfWeek>\n"
1790                         "<WeeksInterval>1</WeeksInterval>\n"
1791                         "</ScheduleByWeek>\n");
1792                 break;
1793
1794         default:
1795                 break;
1796         }
1797
1798         xml = "</CalendarTrigger>\n"
1799               "</Triggers>\n"
1800               "<Principals>\n"
1801               "<Principal id=\"Author\">\n"
1802               "<LogonType>InteractiveToken</LogonType>\n"
1803               "<RunLevel>LeastPrivilege</RunLevel>\n"
1804               "</Principal>\n"
1805               "</Principals>\n"
1806               "<Settings>\n"
1807               "<MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>\n"
1808               "<Enabled>true</Enabled>\n"
1809               "<Hidden>true</Hidden>\n"
1810               "<UseUnifiedSchedulingEngine>true</UseUnifiedSchedulingEngine>\n"
1811               "<WakeToRun>false</WakeToRun>\n"
1812               "<ExecutionTimeLimit>PT72H</ExecutionTimeLimit>\n"
1813               "<Priority>7</Priority>\n"
1814               "</Settings>\n"
1815               "<Actions Context=\"Author\">\n"
1816               "<Exec>\n"
1817               "<Command>\"%s\\git.exe\"</Command>\n"
1818               "<Arguments>--exec-path=\"%s\" for-each-repo --config=maintenance.repo maintenance run --schedule=%s</Arguments>\n"
1819               "</Exec>\n"
1820               "</Actions>\n"
1821               "</Task>\n";
1822         fprintf(tfile->fp, xml, exec_path, exec_path, frequency);
1823         strvec_split(&child.args, cmd);
1824         strvec_pushl(&child.args, "/create", "/tn", name, "/f", "/xml",
1825                                   get_tempfile_path(tfile), NULL);
1826         close_tempfile_gently(tfile);
1827
1828         child.no_stdout = 1;
1829         child.no_stderr = 1;
1830
1831         if (start_command(&child))
1832                 die(_("failed to start schtasks"));
1833         result = finish_command(&child);
1834
1835         delete_tempfile(&tfile);
1836         free(name);
1837         return result;
1838 }
1839
1840 static int schtasks_schedule_tasks(const char *cmd)
1841 {
1842         const char *exec_path = git_exec_path();
1843
1844         return schtasks_schedule_task(exec_path, SCHEDULE_HOURLY, cmd) ||
1845                 schtasks_schedule_task(exec_path, SCHEDULE_DAILY, cmd) ||
1846                 schtasks_schedule_task(exec_path, SCHEDULE_WEEKLY, cmd);
1847 }
1848
1849 static int schtasks_update_schedule(int run_maintenance, int fd, const char *cmd)
1850 {
1851         if (run_maintenance)
1852                 return schtasks_schedule_tasks(cmd);
1853         else
1854                 return schtasks_remove_tasks(cmd);
1855 }
1856
1857 #define BEGIN_LINE "# BEGIN GIT MAINTENANCE SCHEDULE"
1858 #define END_LINE "# END GIT MAINTENANCE SCHEDULE"
1859
1860 static int crontab_update_schedule(int run_maintenance, int fd, const char *cmd)
1861 {
1862         int result = 0;
1863         int in_old_region = 0;
1864         struct child_process crontab_list = CHILD_PROCESS_INIT;
1865         struct child_process crontab_edit = CHILD_PROCESS_INIT;
1866         FILE *cron_list, *cron_in;
1867         struct strbuf line = STRBUF_INIT;
1868
1869         strvec_split(&crontab_list.args, cmd);
1870         strvec_push(&crontab_list.args, "-l");
1871         crontab_list.in = -1;
1872         crontab_list.out = dup(fd);
1873         crontab_list.git_cmd = 0;
1874
1875         if (start_command(&crontab_list))
1876                 return error(_("failed to run 'crontab -l'; your system might not support 'cron'"));
1877
1878         /* Ignore exit code, as an empty crontab will return error. */
1879         finish_command(&crontab_list);
1880
1881         /*
1882          * Read from the .lock file, filtering out the old
1883          * schedule while appending the new schedule.
1884          */
1885         cron_list = fdopen(fd, "r");
1886         rewind(cron_list);
1887
1888         strvec_split(&crontab_edit.args, cmd);
1889         crontab_edit.in = -1;
1890         crontab_edit.git_cmd = 0;
1891
1892         if (start_command(&crontab_edit))
1893                 return error(_("failed to run 'crontab'; your system might not support 'cron'"));
1894
1895         cron_in = fdopen(crontab_edit.in, "w");
1896         if (!cron_in) {
1897                 result = error(_("failed to open stdin of 'crontab'"));
1898                 goto done_editing;
1899         }
1900
1901         while (!strbuf_getline_lf(&line, cron_list)) {
1902                 if (!in_old_region && !strcmp(line.buf, BEGIN_LINE))
1903                         in_old_region = 1;
1904                 else if (in_old_region && !strcmp(line.buf, END_LINE))
1905                         in_old_region = 0;
1906                 else if (!in_old_region)
1907                         fprintf(cron_in, "%s\n", line.buf);
1908         }
1909
1910         if (run_maintenance) {
1911                 struct strbuf line_format = STRBUF_INIT;
1912                 const char *exec_path = git_exec_path();
1913
1914                 fprintf(cron_in, "%s\n", BEGIN_LINE);
1915                 fprintf(cron_in,
1916                         "# The following schedule was created by Git\n");
1917                 fprintf(cron_in, "# Any edits made in this region might be\n");
1918                 fprintf(cron_in,
1919                         "# replaced in the future by a Git command.\n\n");
1920
1921                 strbuf_addf(&line_format,
1922                             "%%s %%s * * %%s \"%s/git\" --exec-path=\"%s\" for-each-repo --config=maintenance.repo maintenance run --schedule=%%s\n",
1923                             exec_path, exec_path);
1924                 fprintf(cron_in, line_format.buf, "0", "1-23", "*", "hourly");
1925                 fprintf(cron_in, line_format.buf, "0", "0", "1-6", "daily");
1926                 fprintf(cron_in, line_format.buf, "0", "0", "0", "weekly");
1927                 strbuf_release(&line_format);
1928
1929                 fprintf(cron_in, "\n%s\n", END_LINE);
1930         }
1931
1932         fflush(cron_in);
1933         fclose(cron_in);
1934         close(crontab_edit.in);
1935
1936 done_editing:
1937         if (finish_command(&crontab_edit))
1938                 result = error(_("'crontab' died"));
1939         else
1940                 fclose(cron_list);
1941         return result;
1942 }
1943
1944 #if defined(__APPLE__)
1945 static const char platform_scheduler[] = "launchctl";
1946 #elif defined(GIT_WINDOWS_NATIVE)
1947 static const char platform_scheduler[] = "schtasks";
1948 #else
1949 static const char platform_scheduler[] = "crontab";
1950 #endif
1951
1952 static int update_background_schedule(int enable)
1953 {
1954         int result;
1955         const char *scheduler = platform_scheduler;
1956         const char *cmd = scheduler;
1957         char *testing;
1958         struct lock_file lk;
1959         char *lock_path = xstrfmt("%s/schedule", the_repository->objects->odb->path);
1960
1961         testing = xstrdup_or_null(getenv("GIT_TEST_MAINT_SCHEDULER"));
1962         if (testing) {
1963                 char *sep = strchr(testing, ':');
1964                 if (!sep)
1965                         die("GIT_TEST_MAINT_SCHEDULER unparseable: %s", testing);
1966                 *sep = '\0';
1967                 scheduler = testing;
1968                 cmd = sep + 1;
1969         }
1970
1971         if (hold_lock_file_for_update(&lk, lock_path, LOCK_NO_DEREF) < 0)
1972                 return error(_("another process is scheduling background maintenance"));
1973
1974         if (!strcmp(scheduler, "launchctl"))
1975                 result = launchctl_update_schedule(enable, get_lock_file_fd(&lk), cmd);
1976         else if (!strcmp(scheduler, "schtasks"))
1977                 result = schtasks_update_schedule(enable, get_lock_file_fd(&lk), cmd);
1978         else if (!strcmp(scheduler, "crontab"))
1979                 result = crontab_update_schedule(enable, get_lock_file_fd(&lk), cmd);
1980         else
1981                 die("unknown background scheduler: %s", scheduler);
1982
1983         rollback_lock_file(&lk);
1984         free(testing);
1985         return result;
1986 }
1987
1988 static int maintenance_start(void)
1989 {
1990         if (maintenance_register())
1991                 warning(_("failed to add repo to global config"));
1992
1993         return update_background_schedule(1);
1994 }
1995
1996 static int maintenance_stop(void)
1997 {
1998         return update_background_schedule(0);
1999 }
2000
2001 static const char builtin_maintenance_usage[] = N_("git maintenance <subcommand> [<options>]");
2002
2003 int cmd_maintenance(int argc, const char **argv, const char *prefix)
2004 {
2005         if (argc < 2 ||
2006             (argc == 2 && !strcmp(argv[1], "-h")))
2007                 usage(builtin_maintenance_usage);
2008
2009         if (!strcmp(argv[1], "run"))
2010                 return maintenance_run(argc - 1, argv + 1, prefix);
2011         if (!strcmp(argv[1], "start"))
2012                 return maintenance_start();
2013         if (!strcmp(argv[1], "stop"))
2014                 return maintenance_stop();
2015         if (!strcmp(argv[1], "register"))
2016                 return maintenance_register();
2017         if (!strcmp(argv[1], "unregister"))
2018                 return maintenance_unregister();
2019
2020         die(_("invalid subcommand: %s"), argv[1]);
2021 }