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