travis-ci: add static analysis build job to run coccicheck
[git] / builtin / gc.c
1 /*
2  * git gc builtin command
3  *
4  * Cleanup unreachable files and optimize the repository.
5  *
6  * Copyright (c) 2007 James Bowes
7  *
8  * Based on git-gc.sh, which is
9  *
10  * Copyright (c) 2006 Shawn O. Pearce
11  */
12
13 #include "builtin.h"
14 #include "tempfile.h"
15 #include "lockfile.h"
16 #include "parse-options.h"
17 #include "run-command.h"
18 #include "sigchain.h"
19 #include "argv-array.h"
20 #include "commit.h"
21
22 #define FAILED_RUN "failed to run %s"
23
24 static const char * const builtin_gc_usage[] = {
25         N_("git gc [<options>]"),
26         NULL
27 };
28
29 static int pack_refs = 1;
30 static int prune_reflogs = 1;
31 static int aggressive_depth = 50;
32 static int aggressive_window = 250;
33 static int gc_auto_threshold = 6700;
34 static int gc_auto_pack_limit = 50;
35 static int detach_auto = 1;
36 static unsigned long gc_log_expire_time;
37 static const char *gc_log_expire = "1.day.ago";
38 static const char *prune_expire = "2.weeks.ago";
39 static const char *prune_worktrees_expire = "3.months.ago";
40
41 static struct argv_array pack_refs_cmd = ARGV_ARRAY_INIT;
42 static struct argv_array reflog = ARGV_ARRAY_INIT;
43 static struct argv_array repack = ARGV_ARRAY_INIT;
44 static struct argv_array prune = ARGV_ARRAY_INIT;
45 static struct argv_array prune_worktrees = ARGV_ARRAY_INIT;
46 static struct argv_array rerere = ARGV_ARRAY_INIT;
47
48 static struct tempfile pidfile;
49 static struct lock_file log_lock;
50
51 static struct string_list pack_garbage = STRING_LIST_INIT_DUP;
52
53 static void clean_pack_garbage(void)
54 {
55         int i;
56         for (i = 0; i < pack_garbage.nr; i++)
57                 unlink_or_warn(pack_garbage.items[i].string);
58         string_list_clear(&pack_garbage, 0);
59 }
60
61 static void report_pack_garbage(unsigned seen_bits, const char *path)
62 {
63         if (seen_bits == PACKDIR_FILE_IDX)
64                 string_list_append(&pack_garbage, path);
65 }
66
67 static void git_config_date_string(const char *key, const char **output)
68 {
69         if (git_config_get_string_const(key, output))
70                 return;
71         if (strcmp(*output, "now")) {
72                 unsigned long now = approxidate("now");
73                 if (approxidate(*output) >= now)
74                         git_die_config(key, _("Invalid %s: '%s'"), key, *output);
75         }
76 }
77
78 static void process_log_file(void)
79 {
80         struct stat st;
81         if (fstat(get_lock_file_fd(&log_lock), &st)) {
82                 /*
83                  * Perhaps there was an i/o error or another
84                  * unlikely situation.  Try to make a note of
85                  * this in gc.log along with any existing
86                  * messages.
87                  */
88                 int saved_errno = errno;
89                 fprintf(stderr, _("Failed to fstat %s: %s"),
90                         get_tempfile_path(&log_lock.tempfile),
91                         strerror(saved_errno));
92                 fflush(stderr);
93                 commit_lock_file(&log_lock);
94                 errno = saved_errno;
95         } else if (st.st_size) {
96                 /* There was some error recorded in the lock file */
97                 commit_lock_file(&log_lock);
98         } else {
99                 /* No error, clean up any old gc.log */
100                 unlink(git_path("gc.log"));
101                 rollback_lock_file(&log_lock);
102         }
103 }
104
105 static void process_log_file_at_exit(void)
106 {
107         fflush(stderr);
108         process_log_file();
109 }
110
111 static void process_log_file_on_signal(int signo)
112 {
113         process_log_file();
114         sigchain_pop(signo);
115         raise(signo);
116 }
117
118 static void gc_config(void)
119 {
120         const char *value;
121
122         if (!git_config_get_value("gc.packrefs", &value)) {
123                 if (value && !strcmp(value, "notbare"))
124                         pack_refs = -1;
125                 else
126                         pack_refs = git_config_bool("gc.packrefs", value);
127         }
128
129         git_config_get_int("gc.aggressivewindow", &aggressive_window);
130         git_config_get_int("gc.aggressivedepth", &aggressive_depth);
131         git_config_get_int("gc.auto", &gc_auto_threshold);
132         git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
133         git_config_get_bool("gc.autodetach", &detach_auto);
134         git_config_date_string("gc.pruneexpire", &prune_expire);
135         git_config_date_string("gc.worktreepruneexpire", &prune_worktrees_expire);
136         git_config_date_string("gc.logexpiry", &gc_log_expire);
137
138         git_config(git_default_config, NULL);
139 }
140
141 static int too_many_loose_objects(void)
142 {
143         /*
144          * Quickly check if a "gc" is needed, by estimating how
145          * many loose objects there are.  Because SHA-1 is evenly
146          * distributed, we can check only one and get a reasonable
147          * estimate.
148          */
149         char path[PATH_MAX];
150         const char *objdir = get_object_directory();
151         DIR *dir;
152         struct dirent *ent;
153         int auto_threshold;
154         int num_loose = 0;
155         int needed = 0;
156
157         if (gc_auto_threshold <= 0)
158                 return 0;
159
160         if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) {
161                 warning(_("insanely long object directory %.*s"), 50, objdir);
162                 return 0;
163         }
164         dir = opendir(path);
165         if (!dir)
166                 return 0;
167
168         auto_threshold = (gc_auto_threshold + 255) / 256;
169         while ((ent = readdir(dir)) != NULL) {
170                 if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
171                     ent->d_name[38] != '\0')
172                         continue;
173                 if (++num_loose > auto_threshold) {
174                         needed = 1;
175                         break;
176                 }
177         }
178         closedir(dir);
179         return needed;
180 }
181
182 static int too_many_packs(void)
183 {
184         struct packed_git *p;
185         int cnt;
186
187         if (gc_auto_pack_limit <= 0)
188                 return 0;
189
190         prepare_packed_git();
191         for (cnt = 0, p = packed_git; p; p = p->next) {
192                 if (!p->pack_local)
193                         continue;
194                 if (p->pack_keep)
195                         continue;
196                 /*
197                  * Perhaps check the size of the pack and count only
198                  * very small ones here?
199                  */
200                 cnt++;
201         }
202         return gc_auto_pack_limit < cnt;
203 }
204
205 static void add_repack_all_option(void)
206 {
207         if (prune_expire && !strcmp(prune_expire, "now"))
208                 argv_array_push(&repack, "-a");
209         else {
210                 argv_array_push(&repack, "-A");
211                 if (prune_expire)
212                         argv_array_pushf(&repack, "--unpack-unreachable=%s", prune_expire);
213         }
214 }
215
216 static void add_repack_incremental_option(void)
217 {
218        argv_array_push(&repack, "--no-write-bitmap-index");
219 }
220
221 static int need_to_gc(void)
222 {
223         /*
224          * Setting gc.auto to 0 or negative can disable the
225          * automatic gc.
226          */
227         if (gc_auto_threshold <= 0)
228                 return 0;
229
230         /*
231          * If there are too many loose objects, but not too many
232          * packs, we run "repack -d -l".  If there are too many packs,
233          * we run "repack -A -d -l".  Otherwise we tell the caller
234          * there is no need.
235          */
236         if (too_many_packs())
237                 add_repack_all_option();
238         else if (too_many_loose_objects())
239                 add_repack_incremental_option();
240         else
241                 return 0;
242
243         if (run_hook_le(NULL, "pre-auto-gc", NULL))
244                 return 0;
245         return 1;
246 }
247
248 /* return NULL on success, else hostname running the gc */
249 static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
250 {
251         static struct lock_file lock;
252         char my_host[128];
253         struct strbuf sb = STRBUF_INIT;
254         struct stat st;
255         uintmax_t pid;
256         FILE *fp;
257         int fd;
258         char *pidfile_path;
259
260         if (is_tempfile_active(&pidfile))
261                 /* already locked */
262                 return NULL;
263
264         if (gethostname(my_host, sizeof(my_host)))
265                 xsnprintf(my_host, sizeof(my_host), "unknown");
266
267         pidfile_path = git_pathdup("gc.pid");
268         fd = hold_lock_file_for_update(&lock, pidfile_path,
269                                        LOCK_DIE_ON_ERROR);
270         if (!force) {
271                 static char locking_host[128];
272                 int should_exit;
273                 fp = fopen(pidfile_path, "r");
274                 memset(locking_host, 0, sizeof(locking_host));
275                 should_exit =
276                         fp != NULL &&
277                         !fstat(fileno(fp), &st) &&
278                         /*
279                          * 12 hour limit is very generous as gc should
280                          * never take that long. On the other hand we
281                          * don't really need a strict limit here,
282                          * running gc --auto one day late is not a big
283                          * problem. --force can be used in manual gc
284                          * after the user verifies that no gc is
285                          * running.
286                          */
287                         time(NULL) - st.st_mtime <= 12 * 3600 &&
288                         fscanf(fp, "%"SCNuMAX" %127c", &pid, locking_host) == 2 &&
289                         /* be gentle to concurrent "gc" on remote hosts */
290                         (strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM);
291                 if (fp != NULL)
292                         fclose(fp);
293                 if (should_exit) {
294                         if (fd >= 0)
295                                 rollback_lock_file(&lock);
296                         *ret_pid = pid;
297                         free(pidfile_path);
298                         return locking_host;
299                 }
300         }
301
302         strbuf_addf(&sb, "%"PRIuMAX" %s",
303                     (uintmax_t) getpid(), my_host);
304         write_in_full(fd, sb.buf, sb.len);
305         strbuf_release(&sb);
306         commit_lock_file(&lock);
307         register_tempfile(&pidfile, pidfile_path);
308         free(pidfile_path);
309         return NULL;
310 }
311
312 static int report_last_gc_error(void)
313 {
314         struct strbuf sb = STRBUF_INIT;
315         int ret = 0;
316         struct stat st;
317         char *gc_log_path = git_pathdup("gc.log");
318
319         if (stat(gc_log_path, &st)) {
320                 if (errno == ENOENT)
321                         goto done;
322
323                 ret = error_errno(_("Can't stat %s"), gc_log_path);
324                 goto done;
325         }
326
327         if (st.st_mtime < gc_log_expire_time)
328                 goto done;
329
330         ret = strbuf_read_file(&sb, gc_log_path, 0);
331         if (ret > 0)
332                 ret = error(_("The last gc run reported the following. "
333                                "Please correct the root cause\n"
334                                "and remove %s.\n"
335                                "Automatic cleanup will not be performed "
336                                "until the file is removed.\n\n"
337                                "%s"),
338                             gc_log_path, sb.buf);
339         strbuf_release(&sb);
340 done:
341         free(gc_log_path);
342         return ret;
343 }
344
345 static int gc_before_repack(void)
346 {
347         if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
348                 return error(FAILED_RUN, pack_refs_cmd.argv[0]);
349
350         if (prune_reflogs && run_command_v_opt(reflog.argv, RUN_GIT_CMD))
351                 return error(FAILED_RUN, reflog.argv[0]);
352
353         pack_refs = 0;
354         prune_reflogs = 0;
355         return 0;
356 }
357
358 int cmd_gc(int argc, const char **argv, const char *prefix)
359 {
360         int aggressive = 0;
361         int auto_gc = 0;
362         int quiet = 0;
363         int force = 0;
364         const char *name;
365         pid_t pid;
366         int daemonized = 0;
367
368         struct option builtin_gc_options[] = {
369                 OPT__QUIET(&quiet, N_("suppress progress reporting")),
370                 { OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
371                         N_("prune unreferenced objects"),
372                         PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
373                 OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
374                 OPT_BOOL(0, "auto", &auto_gc, N_("enable auto-gc mode")),
375                 OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")),
376                 OPT_END()
377         };
378
379         if (argc == 2 && !strcmp(argv[1], "-h"))
380                 usage_with_options(builtin_gc_usage, builtin_gc_options);
381
382         argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
383         argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL);
384         argv_array_pushl(&repack, "repack", "-d", "-l", NULL);
385         argv_array_pushl(&prune, "prune", "--expire", NULL);
386         argv_array_pushl(&prune_worktrees, "worktree", "prune", "--expire", NULL);
387         argv_array_pushl(&rerere, "rerere", "gc", NULL);
388
389         /* default expiry time, overwritten in gc_config */
390         gc_config();
391         if (parse_expiry_date(gc_log_expire, &gc_log_expire_time))
392                 die(_("Failed to parse gc.logexpiry value %s"), gc_log_expire);
393
394         if (pack_refs < 0)
395                 pack_refs = !is_bare_repository();
396
397         argc = parse_options(argc, argv, prefix, builtin_gc_options,
398                              builtin_gc_usage, 0);
399         if (argc > 0)
400                 usage_with_options(builtin_gc_usage, builtin_gc_options);
401
402         if (aggressive) {
403                 argv_array_push(&repack, "-f");
404                 if (aggressive_depth > 0)
405                         argv_array_pushf(&repack, "--depth=%d", aggressive_depth);
406                 if (aggressive_window > 0)
407                         argv_array_pushf(&repack, "--window=%d", aggressive_window);
408         }
409         if (quiet)
410                 argv_array_push(&repack, "-q");
411
412         if (auto_gc) {
413                 /*
414                  * Auto-gc should be least intrusive as possible.
415                  */
416                 if (!need_to_gc())
417                         return 0;
418                 if (!quiet) {
419                         if (detach_auto)
420                                 fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n"));
421                         else
422                                 fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
423                         fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n"));
424                 }
425                 if (detach_auto) {
426                         if (report_last_gc_error())
427                                 return -1;
428
429                         if (gc_before_repack())
430                                 return -1;
431                         /*
432                          * failure to daemonize is ok, we'll continue
433                          * in foreground
434                          */
435                         daemonized = !daemonize();
436                 }
437         } else
438                 add_repack_all_option();
439
440         name = lock_repo_for_gc(force, &pid);
441         if (name) {
442                 if (auto_gc)
443                         return 0; /* be quiet on --auto */
444                 die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
445                     name, (uintmax_t)pid);
446         }
447
448         if (daemonized) {
449                 hold_lock_file_for_update(&log_lock,
450                                           git_path("gc.log"),
451                                           LOCK_DIE_ON_ERROR);
452                 dup2(get_lock_file_fd(&log_lock), 2);
453                 sigchain_push_common(process_log_file_on_signal);
454                 atexit(process_log_file_at_exit);
455         }
456
457         if (gc_before_repack())
458                 return -1;
459
460         if (!repository_format_precious_objects) {
461                 if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
462                         return error(FAILED_RUN, repack.argv[0]);
463
464                 if (prune_expire) {
465                         argv_array_push(&prune, prune_expire);
466                         if (quiet)
467                                 argv_array_push(&prune, "--no-progress");
468                         if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
469                                 return error(FAILED_RUN, prune.argv[0]);
470                 }
471         }
472
473         if (prune_worktrees_expire) {
474                 argv_array_push(&prune_worktrees, prune_worktrees_expire);
475                 if (run_command_v_opt(prune_worktrees.argv, RUN_GIT_CMD))
476                         return error(FAILED_RUN, prune_worktrees.argv[0]);
477         }
478
479         if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
480                 return error(FAILED_RUN, rerere.argv[0]);
481
482         report_garbage = report_pack_garbage;
483         reprepare_packed_git();
484         if (pack_garbage.nr > 0)
485                 clean_pack_garbage();
486
487         if (auto_gc && too_many_loose_objects())
488                 warning(_("There are too many unreachable loose objects; "
489                         "run 'git prune' to remove them."));
490
491         if (!daemonized)
492                 unlink(git_path("gc.log"));
493
494         return 0;
495 }