2 * git gc builtin command
4 * Cleanup unreachable files and optimize the repository.
6 * Copyright (c) 2007 James Bowes
8 * Based on git-gc.sh, which is
10 * Copyright (c) 2006 Shawn O. Pearce
14 #include "repository.h"
18 #include "parse-options.h"
19 #include "run-command.h"
21 #include "argv-array.h"
24 #include "object-store.h"
26 #define FAILED_RUN "failed to run %s"
28 static const char * const builtin_gc_usage
[] = {
29 N_("git gc [<options>]"),
33 static int pack_refs
= 1;
34 static int prune_reflogs
= 1;
35 static int aggressive_depth
= 50;
36 static int aggressive_window
= 250;
37 static int gc_auto_threshold
= 6700;
38 static int gc_auto_pack_limit
= 50;
39 static int detach_auto
= 1;
40 static timestamp_t gc_log_expire_time
;
41 static const char *gc_log_expire
= "1.day.ago";
42 static const char *prune_expire
= "2.weeks.ago";
43 static const char *prune_worktrees_expire
= "3.months.ago";
45 static struct argv_array pack_refs_cmd
= ARGV_ARRAY_INIT
;
46 static struct argv_array reflog
= ARGV_ARRAY_INIT
;
47 static struct argv_array repack
= ARGV_ARRAY_INIT
;
48 static struct argv_array prune
= ARGV_ARRAY_INIT
;
49 static struct argv_array prune_worktrees
= ARGV_ARRAY_INIT
;
50 static struct argv_array rerere
= ARGV_ARRAY_INIT
;
52 static struct tempfile
*pidfile
;
53 static struct lock_file log_lock
;
55 static struct string_list pack_garbage
= STRING_LIST_INIT_DUP
;
57 static void clean_pack_garbage(void)
60 for (i
= 0; i
< pack_garbage
.nr
; i
++)
61 unlink_or_warn(pack_garbage
.items
[i
].string
);
62 string_list_clear(&pack_garbage
, 0);
65 static void report_pack_garbage(unsigned seen_bits
, const char *path
)
67 if (seen_bits
== PACKDIR_FILE_IDX
)
68 string_list_append(&pack_garbage
, path
);
71 static void process_log_file(void)
74 if (fstat(get_lock_file_fd(&log_lock
), &st
)) {
76 * Perhaps there was an i/o error or another
77 * unlikely situation. Try to make a note of
78 * this in gc.log along with any existing
81 int saved_errno
= errno
;
82 fprintf(stderr
, _("Failed to fstat %s: %s"),
83 get_tempfile_path(log_lock
.tempfile
),
84 strerror(saved_errno
));
86 commit_lock_file(&log_lock
);
88 } else if (st
.st_size
) {
89 /* There was some error recorded in the lock file */
90 commit_lock_file(&log_lock
);
92 /* No error, clean up any old gc.log */
93 unlink(git_path("gc.log"));
94 rollback_lock_file(&log_lock
);
98 static void process_log_file_at_exit(void)
104 static void process_log_file_on_signal(int signo
)
111 static void gc_config(void)
115 if (!git_config_get_value("gc.packrefs", &value
)) {
116 if (value
&& !strcmp(value
, "notbare"))
119 pack_refs
= git_config_bool("gc.packrefs", value
);
122 git_config_get_int("gc.aggressivewindow", &aggressive_window
);
123 git_config_get_int("gc.aggressivedepth", &aggressive_depth
);
124 git_config_get_int("gc.auto", &gc_auto_threshold
);
125 git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit
);
126 git_config_get_bool("gc.autodetach", &detach_auto
);
127 git_config_get_expiry("gc.pruneexpire", &prune_expire
);
128 git_config_get_expiry("gc.worktreepruneexpire", &prune_worktrees_expire
);
129 git_config_get_expiry("gc.logexpiry", &gc_log_expire
);
131 git_config(git_default_config
, NULL
);
134 static int too_many_loose_objects(void)
137 * Quickly check if a "gc" is needed, by estimating how
138 * many loose objects there are. Because SHA-1 is evenly
139 * distributed, we can check only one and get a reasonable
148 if (gc_auto_threshold
<= 0)
151 dir
= opendir(git_path("objects/17"));
155 auto_threshold
= DIV_ROUND_UP(gc_auto_threshold
, 256);
156 while ((ent
= readdir(dir
)) != NULL
) {
157 if (strspn(ent
->d_name
, "0123456789abcdef") != 38 ||
158 ent
->d_name
[38] != '\0')
160 if (++num_loose
> auto_threshold
) {
169 static int too_many_packs(void)
171 struct packed_git
*p
;
174 if (gc_auto_pack_limit
<= 0)
177 for (cnt
= 0, p
= get_packed_git(the_repository
); p
; p
= p
->next
) {
183 * Perhaps check the size of the pack and count only
184 * very small ones here?
188 return gc_auto_pack_limit
< cnt
;
191 static void add_repack_all_option(void)
193 if (prune_expire
&& !strcmp(prune_expire
, "now"))
194 argv_array_push(&repack
, "-a");
196 argv_array_push(&repack
, "-A");
198 argv_array_pushf(&repack
, "--unpack-unreachable=%s", prune_expire
);
202 static void add_repack_incremental_option(void)
204 argv_array_push(&repack
, "--no-write-bitmap-index");
207 static int need_to_gc(void)
210 * Setting gc.auto to 0 or negative can disable the
213 if (gc_auto_threshold
<= 0)
217 * If there are too many loose objects, but not too many
218 * packs, we run "repack -d -l". If there are too many packs,
219 * we run "repack -A -d -l". Otherwise we tell the caller
222 if (too_many_packs())
223 add_repack_all_option();
224 else if (too_many_loose_objects())
225 add_repack_incremental_option();
229 if (run_hook_le(NULL
, "pre-auto-gc", NULL
))
234 /* return NULL on success, else hostname running the gc */
235 static const char *lock_repo_for_gc(int force
, pid_t
* ret_pid
)
237 static struct lock_file lock
;
238 char my_host
[HOST_NAME_MAX
+ 1];
239 struct strbuf sb
= STRBUF_INIT
;
246 if (is_tempfile_active(pidfile
))
250 if (xgethostname(my_host
, sizeof(my_host
)))
251 xsnprintf(my_host
, sizeof(my_host
), "unknown");
253 pidfile_path
= git_pathdup("gc.pid");
254 fd
= hold_lock_file_for_update(&lock
, pidfile_path
,
257 static char locking_host
[HOST_NAME_MAX
+ 1];
258 static char *scan_fmt
;
262 scan_fmt
= xstrfmt("%s %%%ds", "%"SCNuMAX
, HOST_NAME_MAX
);
263 fp
= fopen(pidfile_path
, "r");
264 memset(locking_host
, 0, sizeof(locking_host
));
267 !fstat(fileno(fp
), &st
) &&
269 * 12 hour limit is very generous as gc should
270 * never take that long. On the other hand we
271 * don't really need a strict limit here,
272 * running gc --auto one day late is not a big
273 * problem. --force can be used in manual gc
274 * after the user verifies that no gc is
277 time(NULL
) - st
.st_mtime
<= 12 * 3600 &&
278 fscanf(fp
, scan_fmt
, &pid
, locking_host
) == 2 &&
279 /* be gentle to concurrent "gc" on remote hosts */
280 (strcmp(locking_host
, my_host
) || !kill(pid
, 0) || errno
== EPERM
);
285 rollback_lock_file(&lock
);
292 strbuf_addf(&sb
, "%"PRIuMAX
" %s",
293 (uintmax_t) getpid(), my_host
);
294 write_in_full(fd
, sb
.buf
, sb
.len
);
296 commit_lock_file(&lock
);
297 pidfile
= register_tempfile(pidfile_path
);
302 static int report_last_gc_error(void)
304 struct strbuf sb
= STRBUF_INIT
;
307 char *gc_log_path
= git_pathdup("gc.log");
309 if (stat(gc_log_path
, &st
)) {
313 ret
= error_errno(_("Can't stat %s"), gc_log_path
);
317 if (st
.st_mtime
< gc_log_expire_time
)
320 ret
= strbuf_read_file(&sb
, gc_log_path
, 0);
322 ret
= error(_("The last gc run reported the following. "
323 "Please correct the root cause\n"
325 "Automatic cleanup will not be performed "
326 "until the file is removed.\n\n"
328 gc_log_path
, sb
.buf
);
335 static int gc_before_repack(void)
337 if (pack_refs
&& run_command_v_opt(pack_refs_cmd
.argv
, RUN_GIT_CMD
))
338 return error(FAILED_RUN
, pack_refs_cmd
.argv
[0]);
340 if (prune_reflogs
&& run_command_v_opt(reflog
.argv
, RUN_GIT_CMD
))
341 return error(FAILED_RUN
, reflog
.argv
[0]);
348 int cmd_gc(int argc
, const char **argv
, const char *prefix
)
358 struct option builtin_gc_options
[] = {
359 OPT__QUIET(&quiet
, N_("suppress progress reporting")),
360 { OPTION_STRING
, 0, "prune", &prune_expire
, N_("date"),
361 N_("prune unreferenced objects"),
362 PARSE_OPT_OPTARG
, NULL
, (intptr_t)prune_expire
},
363 OPT_BOOL(0, "aggressive", &aggressive
, N_("be more thorough (increased runtime)")),
364 OPT_BOOL_F(0, "auto", &auto_gc
, N_("enable auto-gc mode"),
365 PARSE_OPT_NOCOMPLETE
),
366 OPT_BOOL_F(0, "force", &force
,
367 N_("force running gc even if there may be another gc running"),
368 PARSE_OPT_NOCOMPLETE
),
372 if (argc
== 2 && !strcmp(argv
[1], "-h"))
373 usage_with_options(builtin_gc_usage
, builtin_gc_options
);
375 argv_array_pushl(&pack_refs_cmd
, "pack-refs", "--all", "--prune", NULL
);
376 argv_array_pushl(&reflog
, "reflog", "expire", "--all", NULL
);
377 argv_array_pushl(&repack
, "repack", "-d", "-l", NULL
);
378 argv_array_pushl(&prune
, "prune", "--expire", NULL
);
379 argv_array_pushl(&prune_worktrees
, "worktree", "prune", "--expire", NULL
);
380 argv_array_pushl(&rerere
, "rerere", "gc", NULL
);
382 /* default expiry time, overwritten in gc_config */
384 if (parse_expiry_date(gc_log_expire
, &gc_log_expire_time
))
385 die(_("Failed to parse gc.logexpiry value %s"), gc_log_expire
);
388 pack_refs
= !is_bare_repository();
390 argc
= parse_options(argc
, argv
, prefix
, builtin_gc_options
,
391 builtin_gc_usage
, 0);
393 usage_with_options(builtin_gc_usage
, builtin_gc_options
);
396 argv_array_push(&repack
, "-f");
397 if (aggressive_depth
> 0)
398 argv_array_pushf(&repack
, "--depth=%d", aggressive_depth
);
399 if (aggressive_window
> 0)
400 argv_array_pushf(&repack
, "--window=%d", aggressive_window
);
403 argv_array_push(&repack
, "-q");
407 * Auto-gc should be least intrusive as possible.
413 fprintf(stderr
, _("Auto packing the repository in background for optimum performance.\n"));
415 fprintf(stderr
, _("Auto packing the repository for optimum performance.\n"));
416 fprintf(stderr
, _("See \"git help gc\" for manual housekeeping.\n"));
419 if (report_last_gc_error())
422 if (lock_repo_for_gc(force
, &pid
))
424 if (gc_before_repack())
426 delete_tempfile(&pidfile
);
429 * failure to daemonize is ok, we'll continue
432 daemonized
= !daemonize();
435 add_repack_all_option();
437 name
= lock_repo_for_gc(force
, &pid
);
440 return 0; /* be quiet on --auto */
441 die(_("gc is already running on machine '%s' pid %"PRIuMAX
" (use --force if not)"),
442 name
, (uintmax_t)pid
);
446 hold_lock_file_for_update(&log_lock
,
449 dup2(get_lock_file_fd(&log_lock
), 2);
450 sigchain_push_common(process_log_file_on_signal
);
451 atexit(process_log_file_at_exit
);
454 if (gc_before_repack())
457 if (!repository_format_precious_objects
) {
458 if (run_command_v_opt(repack
.argv
, RUN_GIT_CMD
))
459 return error(FAILED_RUN
, repack
.argv
[0]);
462 argv_array_push(&prune
, prune_expire
);
464 argv_array_push(&prune
, "--no-progress");
465 if (repository_format_partial_clone
)
466 argv_array_push(&prune
,
467 "--exclude-promisor-objects");
468 if (run_command_v_opt(prune
.argv
, RUN_GIT_CMD
))
469 return error(FAILED_RUN
, prune
.argv
[0]);
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]);
479 if (run_command_v_opt(rerere
.argv
, RUN_GIT_CMD
))
480 return error(FAILED_RUN
, rerere
.argv
[0]);
482 report_garbage
= report_pack_garbage
;
483 reprepare_packed_git(the_repository
);
484 if (pack_garbage
.nr
> 0)
485 clean_pack_garbage();
487 if (auto_gc
&& too_many_loose_objects())
488 warning(_("There are too many unreachable loose objects; "
489 "run 'git prune' to remove them."));
492 unlink(git_path("gc.log"));