gc: config option for running --auto in background
[git/git.git] / builtin / gc.c
CommitLineData
6757ada4
JB
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
baffc0e7 13#include "builtin.h"
6757ada4 14#include "cache.h"
44c637c8 15#include "parse-options.h"
6757ada4 16#include "run-command.h"
4c5baf02 17#include "sigchain.h"
234587fc 18#include "argv-array.h"
eab3296c 19#include "commit.h"
6757ada4
JB
20
21#define FAILED_RUN "failed to run %s"
22
44c637c8 23static const char * const builtin_gc_usage[] = {
6705c162 24 N_("git gc [options]"),
44c637c8
JB
25 NULL
26};
6757ada4 27
56752391 28static int pack_refs = 1;
1c192f34 29static int aggressive_window = 250;
2c3c4399 30static int gc_auto_threshold = 6700;
97063974 31static int gc_auto_pack_limit = 50;
9f673f94 32static int detach_auto = 1;
d3154b44 33static const char *prune_expire = "2.weeks.ago";
6757ada4 34
234587fc
JK
35static struct argv_array pack_refs_cmd = ARGV_ARRAY_INIT;
36static struct argv_array reflog = ARGV_ARRAY_INIT;
37static struct argv_array repack = ARGV_ARRAY_INIT;
38static struct argv_array prune = ARGV_ARRAY_INIT;
39static struct argv_array rerere = ARGV_ARRAY_INIT;
6757ada4 40
4c5baf02
JN
41static char *pidfile;
42
43static void remove_pidfile(void)
44{
45 if (pidfile)
46 unlink(pidfile);
47}
48
49static void remove_pidfile_on_signal(int signo)
50{
51 remove_pidfile();
52 sigchain_pop(signo);
53 raise(signo);
54}
55
ef90d6d4 56static int gc_config(const char *var, const char *value, void *cb)
6757ada4
JB
57{
58 if (!strcmp(var, "gc.packrefs")) {
c5e5a2c0 59 if (value && !strcmp(value, "notbare"))
6757ada4
JB
60 pack_refs = -1;
61 else
62 pack_refs = git_config_bool(var, value);
63 return 0;
64 }
0d7566a5
TT
65 if (!strcmp(var, "gc.aggressivewindow")) {
66 aggressive_window = git_config_int(var, value);
67 return 0;
68 }
2c3c4399
JH
69 if (!strcmp(var, "gc.auto")) {
70 gc_auto_threshold = git_config_int(var, value);
71 return 0;
72 }
17815501
JH
73 if (!strcmp(var, "gc.autopacklimit")) {
74 gc_auto_pack_limit = git_config_int(var, value);
75 return 0;
76 }
9f673f94
NTND
77 if (!strcmp(var, "gc.autodetach")) {
78 detach_auto = git_config_bool(var, value);
79 return 0;
80 }
25ee9731 81 if (!strcmp(var, "gc.pruneexpire")) {
d3154b44 82 if (value && strcmp(value, "now")) {
25ee9731
JS
83 unsigned long now = approxidate("now");
84 if (approxidate(value) >= now)
fea6128b 85 return error(_("Invalid %s: '%s'"), var, value);
25ee9731 86 }
d3154b44 87 return git_config_string(&prune_expire, var, value);
25ee9731 88 }
ef90d6d4 89 return git_default_config(var, value, cb);
6757ada4
JB
90}
91
a087cc98 92static int too_many_loose_objects(void)
2c3c4399
JH
93{
94 /*
95 * Quickly check if a "gc" is needed, by estimating how
96 * many loose objects there are. Because SHA-1 is evenly
97 * distributed, we can check only one and get a reasonable
98 * estimate.
99 */
100 char path[PATH_MAX];
101 const char *objdir = get_object_directory();
102 DIR *dir;
103 struct dirent *ent;
104 int auto_threshold;
105 int num_loose = 0;
106 int needed = 0;
107
17815501
JH
108 if (gc_auto_threshold <= 0)
109 return 0;
110
2c3c4399 111 if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) {
fea6128b 112 warning(_("insanely long object directory %.*s"), 50, objdir);
2c3c4399
JH
113 return 0;
114 }
115 dir = opendir(path);
116 if (!dir)
117 return 0;
118
119 auto_threshold = (gc_auto_threshold + 255) / 256;
120 while ((ent = readdir(dir)) != NULL) {
121 if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
122 ent->d_name[38] != '\0')
123 continue;
124 if (++num_loose > auto_threshold) {
125 needed = 1;
126 break;
127 }
128 }
129 closedir(dir);
130 return needed;
131}
132
17815501
JH
133static int too_many_packs(void)
134{
135 struct packed_git *p;
136 int cnt;
137
138 if (gc_auto_pack_limit <= 0)
139 return 0;
140
141 prepare_packed_git();
142 for (cnt = 0, p = packed_git; p; p = p->next) {
17815501
JH
143 if (!p->pack_local)
144 continue;
01af249f 145 if (p->pack_keep)
17815501
JH
146 continue;
147 /*
148 * Perhaps check the size of the pack and count only
149 * very small ones here?
150 */
151 cnt++;
152 }
153 return gc_auto_pack_limit <= cnt;
154}
155
7e52f566
JK
156static void add_repack_all_option(void)
157{
158 if (prune_expire && !strcmp(prune_expire, "now"))
234587fc 159 argv_array_push(&repack, "-a");
7e52f566 160 else {
234587fc
JK
161 argv_array_push(&repack, "-A");
162 if (prune_expire)
163 argv_array_pushf(&repack, "--unpack-unreachable=%s", prune_expire);
7e52f566
JK
164 }
165}
166
a087cc98
JH
167static int need_to_gc(void)
168{
169 /*
b14d255b
BC
170 * Setting gc.auto to 0 or negative can disable the
171 * automatic gc.
a087cc98 172 */
b14d255b 173 if (gc_auto_threshold <= 0)
95143f9e
JH
174 return 0;
175
17815501
JH
176 /*
177 * If there are too many loose objects, but not too many
178 * packs, we run "repack -d -l". If there are too many packs,
179 * we run "repack -A -d -l". Otherwise we tell the caller
180 * there is no need.
181 */
17815501 182 if (too_many_packs())
7e52f566 183 add_repack_all_option();
17815501
JH
184 else if (!too_many_loose_objects())
185 return 0;
bde30540 186
ae98a008 187 if (run_hook(NULL, "pre-auto-gc", NULL))
bde30540 188 return 0;
95143f9e 189 return 1;
a087cc98
JH
190}
191
64a99eb4
NTND
192/* return NULL on success, else hostname running the gc */
193static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
194{
195 static struct lock_file lock;
196 static char locking_host[128];
197 char my_host[128];
198 struct strbuf sb = STRBUF_INIT;
199 struct stat st;
200 uintmax_t pid;
201 FILE *fp;
202 int fd, should_exit;
203
4c5baf02
JN
204 if (pidfile)
205 /* already locked */
206 return NULL;
207
64a99eb4
NTND
208 if (gethostname(my_host, sizeof(my_host)))
209 strcpy(my_host, "unknown");
210
211 fd = hold_lock_file_for_update(&lock, git_path("gc.pid"),
212 LOCK_DIE_ON_ERROR);
213 if (!force) {
214 fp = fopen(git_path("gc.pid"), "r");
215 memset(locking_host, 0, sizeof(locking_host));
216 should_exit =
217 fp != NULL &&
218 !fstat(fileno(fp), &st) &&
219 /*
220 * 12 hour limit is very generous as gc should
221 * never take that long. On the other hand we
222 * don't really need a strict limit here,
223 * running gc --auto one day late is not a big
224 * problem. --force can be used in manual gc
225 * after the user verifies that no gc is
226 * running.
227 */
228 time(NULL) - st.st_mtime <= 12 * 3600 &&
229 fscanf(fp, "%"PRIuMAX" %127c", &pid, locking_host) == 2 &&
230 /* be gentle to concurrent "gc" on remote hosts */
ed7eda8b 231 (strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM);
64a99eb4
NTND
232 if (fp != NULL)
233 fclose(fp);
234 if (should_exit) {
235 if (fd >= 0)
236 rollback_lock_file(&lock);
237 *ret_pid = pid;
238 return locking_host;
239 }
240 }
241
242 strbuf_addf(&sb, "%"PRIuMAX" %s",
243 (uintmax_t) getpid(), my_host);
244 write_in_full(fd, sb.buf, sb.len);
245 strbuf_release(&sb);
246 commit_lock_file(&lock);
247
4c5baf02
JN
248 pidfile = git_pathdup("gc.pid");
249 sigchain_push_common(remove_pidfile_on_signal);
250 atexit(remove_pidfile);
251
64a99eb4
NTND
252 return NULL;
253}
254
6757ada4
JB
255int cmd_gc(int argc, const char **argv, const char *prefix)
256{
44c637c8 257 int aggressive = 0;
2c3c4399 258 int auto_gc = 0;
a0c14cbb 259 int quiet = 0;
64a99eb4
NTND
260 int force = 0;
261 const char *name;
262 pid_t pid;
6757ada4 263
44c637c8 264 struct option builtin_gc_options[] = {
6705c162
NTND
265 OPT__QUIET(&quiet, N_("suppress progress reporting")),
266 { OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
267 N_("prune unreferenced objects"),
58e9d9d4 268 PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
d5d09d47
SB
269 OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
270 OPT_BOOL(0, "auto", &auto_gc, N_("enable auto-gc mode")),
64a99eb4 271 OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")),
44c637c8
JB
272 OPT_END()
273 };
274
0c8151b6
NTND
275 if (argc == 2 && !strcmp(argv[1], "-h"))
276 usage_with_options(builtin_gc_usage, builtin_gc_options);
277
234587fc
JK
278 argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
279 argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL);
280 argv_array_pushl(&repack, "repack", "-d", "-l", NULL);
281 argv_array_pushl(&prune, "prune", "--expire", NULL );
282 argv_array_pushl(&rerere, "rerere", "gc", NULL);
283
ef90d6d4 284 git_config(gc_config, NULL);
6757ada4
JB
285
286 if (pack_refs < 0)
287 pack_refs = !is_bare_repository();
288
37782920
SB
289 argc = parse_options(argc, argv, prefix, builtin_gc_options,
290 builtin_gc_usage, 0);
44c637c8
JB
291 if (argc > 0)
292 usage_with_options(builtin_gc_usage, builtin_gc_options);
293
294 if (aggressive) {
234587fc
JK
295 argv_array_push(&repack, "-f");
296 argv_array_push(&repack, "--depth=250");
297 if (aggressive_window > 0)
298 argv_array_pushf(&repack, "--window=%d", aggressive_window);
6757ada4 299 }
a0c14cbb 300 if (quiet)
234587fc 301 argv_array_push(&repack, "-q");
6757ada4 302
2c3c4399
JH
303 if (auto_gc) {
304 /*
305 * Auto-gc should be least intrusive as possible.
306 */
2c3c4399
JH
307 if (!need_to_gc())
308 return 0;
9f673f94
NTND
309 if (!quiet) {
310 if (detach_auto)
311 fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n"));
312 else
313 fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
314 fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n"));
315 }
316 if (detach_auto)
317 /*
318 * failure to daemonize is ok, we'll continue
319 * in foreground
320 */
321 daemonize();
a37cce3b 322 } else
7e52f566 323 add_repack_all_option();
2c3c4399 324
64a99eb4
NTND
325 name = lock_repo_for_gc(force, &pid);
326 if (name) {
327 if (auto_gc)
328 return 0; /* be quiet on --auto */
329 die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
330 name, (uintmax_t)pid);
331 }
332
234587fc
JK
333 if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
334 return error(FAILED_RUN, pack_refs_cmd.argv[0]);
6757ada4 335
234587fc
JK
336 if (run_command_v_opt(reflog.argv, RUN_GIT_CMD))
337 return error(FAILED_RUN, reflog.argv[0]);
6757ada4 338
234587fc
JK
339 if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
340 return error(FAILED_RUN, repack.argv[0]);
6757ada4 341
58e9d9d4 342 if (prune_expire) {
234587fc 343 argv_array_push(&prune, prune_expire);
bf0a59b3 344 if (quiet)
234587fc
JK
345 argv_array_push(&prune, "--no-progress");
346 if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
347 return error(FAILED_RUN, prune.argv[0]);
58e9d9d4 348 }
6757ada4 349
234587fc
JK
350 if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
351 return error(FAILED_RUN, rerere.argv[0]);
6757ada4 352
a087cc98 353 if (auto_gc && too_many_loose_objects())
fea6128b
ÆAB
354 warning(_("There are too many unreachable loose objects; "
355 "run 'git prune' to remove them."));
a087cc98 356
6757ada4
JB
357 return 0;
358}