Merge branch 'nd/daemonize-gc' into maint
[git/git.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 "cache.h"
15 #include "parse-options.h"
16 #include "run-command.h"
17 #include "sigchain.h"
18 #include "argv-array.h"
19 #include "commit.h"
20
21 #define FAILED_RUN "failed to run %s"
22
23 static const char * const builtin_gc_usage[] = {
24 N_("git gc [options]"),
25 NULL
26 };
27
28 static int pack_refs = 1;
29 static int prune_reflogs = 1;
30 static int aggressive_depth = 250;
31 static int aggressive_window = 250;
32 static int gc_auto_threshold = 6700;
33 static int gc_auto_pack_limit = 50;
34 static int detach_auto = 1;
35 static const char *prune_expire = "2.weeks.ago";
36
37 static struct argv_array pack_refs_cmd = ARGV_ARRAY_INIT;
38 static struct argv_array reflog = ARGV_ARRAY_INIT;
39 static struct argv_array repack = ARGV_ARRAY_INIT;
40 static struct argv_array prune = ARGV_ARRAY_INIT;
41 static struct argv_array rerere = ARGV_ARRAY_INIT;
42
43 static char *pidfile;
44
45 static void remove_pidfile(void)
46 {
47 if (pidfile)
48 unlink(pidfile);
49 }
50
51 static void remove_pidfile_on_signal(int signo)
52 {
53 remove_pidfile();
54 sigchain_pop(signo);
55 raise(signo);
56 }
57
58 static int gc_config(const char *var, const char *value, void *cb)
59 {
60 if (!strcmp(var, "gc.packrefs")) {
61 if (value && !strcmp(value, "notbare"))
62 pack_refs = -1;
63 else
64 pack_refs = git_config_bool(var, value);
65 return 0;
66 }
67 if (!strcmp(var, "gc.aggressivewindow")) {
68 aggressive_window = git_config_int(var, value);
69 return 0;
70 }
71 if (!strcmp(var, "gc.aggressivedepth")) {
72 aggressive_depth = git_config_int(var, value);
73 return 0;
74 }
75 if (!strcmp(var, "gc.auto")) {
76 gc_auto_threshold = git_config_int(var, value);
77 return 0;
78 }
79 if (!strcmp(var, "gc.autopacklimit")) {
80 gc_auto_pack_limit = git_config_int(var, value);
81 return 0;
82 }
83 if (!strcmp(var, "gc.autodetach")) {
84 detach_auto = git_config_bool(var, value);
85 return 0;
86 }
87 if (!strcmp(var, "gc.pruneexpire")) {
88 if (value && strcmp(value, "now")) {
89 unsigned long now = approxidate("now");
90 if (approxidate(value) >= now)
91 return error(_("Invalid %s: '%s'"), var, value);
92 }
93 return git_config_string(&prune_expire, var, value);
94 }
95 return git_default_config(var, value, cb);
96 }
97
98 static int too_many_loose_objects(void)
99 {
100 /*
101 * Quickly check if a "gc" is needed, by estimating how
102 * many loose objects there are. Because SHA-1 is evenly
103 * distributed, we can check only one and get a reasonable
104 * estimate.
105 */
106 char path[PATH_MAX];
107 const char *objdir = get_object_directory();
108 DIR *dir;
109 struct dirent *ent;
110 int auto_threshold;
111 int num_loose = 0;
112 int needed = 0;
113
114 if (gc_auto_threshold <= 0)
115 return 0;
116
117 if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) {
118 warning(_("insanely long object directory %.*s"), 50, objdir);
119 return 0;
120 }
121 dir = opendir(path);
122 if (!dir)
123 return 0;
124
125 auto_threshold = (gc_auto_threshold + 255) / 256;
126 while ((ent = readdir(dir)) != NULL) {
127 if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
128 ent->d_name[38] != '\0')
129 continue;
130 if (++num_loose > auto_threshold) {
131 needed = 1;
132 break;
133 }
134 }
135 closedir(dir);
136 return needed;
137 }
138
139 static int too_many_packs(void)
140 {
141 struct packed_git *p;
142 int cnt;
143
144 if (gc_auto_pack_limit <= 0)
145 return 0;
146
147 prepare_packed_git();
148 for (cnt = 0, p = packed_git; p; p = p->next) {
149 if (!p->pack_local)
150 continue;
151 if (p->pack_keep)
152 continue;
153 /*
154 * Perhaps check the size of the pack and count only
155 * very small ones here?
156 */
157 cnt++;
158 }
159 return gc_auto_pack_limit <= cnt;
160 }
161
162 static void add_repack_all_option(void)
163 {
164 if (prune_expire && !strcmp(prune_expire, "now"))
165 argv_array_push(&repack, "-a");
166 else {
167 argv_array_push(&repack, "-A");
168 if (prune_expire)
169 argv_array_pushf(&repack, "--unpack-unreachable=%s", prune_expire);
170 }
171 }
172
173 static int need_to_gc(void)
174 {
175 /*
176 * Setting gc.auto to 0 or negative can disable the
177 * automatic gc.
178 */
179 if (gc_auto_threshold <= 0)
180 return 0;
181
182 /*
183 * If there are too many loose objects, but not too many
184 * packs, we run "repack -d -l". If there are too many packs,
185 * we run "repack -A -d -l". Otherwise we tell the caller
186 * there is no need.
187 */
188 if (too_many_packs())
189 add_repack_all_option();
190 else if (!too_many_loose_objects())
191 return 0;
192
193 if (run_hook_le(NULL, "pre-auto-gc", NULL))
194 return 0;
195 return 1;
196 }
197
198 /* return NULL on success, else hostname running the gc */
199 static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
200 {
201 static struct lock_file lock;
202 char my_host[128];
203 struct strbuf sb = STRBUF_INIT;
204 struct stat st;
205 uintmax_t pid;
206 FILE *fp;
207 int fd;
208
209 if (pidfile)
210 /* already locked */
211 return NULL;
212
213 if (gethostname(my_host, sizeof(my_host)))
214 strcpy(my_host, "unknown");
215
216 fd = hold_lock_file_for_update(&lock, git_path("gc.pid"),
217 LOCK_DIE_ON_ERROR);
218 if (!force) {
219 static char locking_host[128];
220 int should_exit;
221 fp = fopen(git_path("gc.pid"), "r");
222 memset(locking_host, 0, sizeof(locking_host));
223 should_exit =
224 fp != NULL &&
225 !fstat(fileno(fp), &st) &&
226 /*
227 * 12 hour limit is very generous as gc should
228 * never take that long. On the other hand we
229 * don't really need a strict limit here,
230 * running gc --auto one day late is not a big
231 * problem. --force can be used in manual gc
232 * after the user verifies that no gc is
233 * running.
234 */
235 time(NULL) - st.st_mtime <= 12 * 3600 &&
236 fscanf(fp, "%"PRIuMAX" %127c", &pid, locking_host) == 2 &&
237 /* be gentle to concurrent "gc" on remote hosts */
238 (strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM);
239 if (fp != NULL)
240 fclose(fp);
241 if (should_exit) {
242 if (fd >= 0)
243 rollback_lock_file(&lock);
244 *ret_pid = pid;
245 return locking_host;
246 }
247 }
248
249 strbuf_addf(&sb, "%"PRIuMAX" %s",
250 (uintmax_t) getpid(), my_host);
251 write_in_full(fd, sb.buf, sb.len);
252 strbuf_release(&sb);
253 commit_lock_file(&lock);
254
255 pidfile = git_pathdup("gc.pid");
256 sigchain_push_common(remove_pidfile_on_signal);
257 atexit(remove_pidfile);
258
259 return NULL;
260 }
261
262 static int gc_before_repack(void)
263 {
264 if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
265 return error(FAILED_RUN, pack_refs_cmd.argv[0]);
266
267 if (prune_reflogs && run_command_v_opt(reflog.argv, RUN_GIT_CMD))
268 return error(FAILED_RUN, reflog.argv[0]);
269
270 pack_refs = 0;
271 prune_reflogs = 0;
272 return 0;
273 }
274
275 int cmd_gc(int argc, const char **argv, const char *prefix)
276 {
277 int aggressive = 0;
278 int auto_gc = 0;
279 int quiet = 0;
280 int force = 0;
281 const char *name;
282 pid_t pid;
283
284 struct option builtin_gc_options[] = {
285 OPT__QUIET(&quiet, N_("suppress progress reporting")),
286 { OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
287 N_("prune unreferenced objects"),
288 PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
289 OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
290 OPT_BOOL(0, "auto", &auto_gc, N_("enable auto-gc mode")),
291 OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")),
292 OPT_END()
293 };
294
295 if (argc == 2 && !strcmp(argv[1], "-h"))
296 usage_with_options(builtin_gc_usage, builtin_gc_options);
297
298 argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
299 argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL);
300 argv_array_pushl(&repack, "repack", "-d", "-l", NULL);
301 argv_array_pushl(&prune, "prune", "--expire", NULL );
302 argv_array_pushl(&rerere, "rerere", "gc", NULL);
303
304 git_config(gc_config, NULL);
305
306 if (pack_refs < 0)
307 pack_refs = !is_bare_repository();
308
309 argc = parse_options(argc, argv, prefix, builtin_gc_options,
310 builtin_gc_usage, 0);
311 if (argc > 0)
312 usage_with_options(builtin_gc_usage, builtin_gc_options);
313
314 if (aggressive) {
315 argv_array_push(&repack, "-f");
316 if (aggressive_depth > 0)
317 argv_array_pushf(&repack, "--depth=%d", aggressive_depth);
318 if (aggressive_window > 0)
319 argv_array_pushf(&repack, "--window=%d", aggressive_window);
320 }
321 if (quiet)
322 argv_array_push(&repack, "-q");
323
324 if (auto_gc) {
325 /*
326 * Auto-gc should be least intrusive as possible.
327 */
328 if (!need_to_gc())
329 return 0;
330 if (!quiet) {
331 if (detach_auto)
332 fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n"));
333 else
334 fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
335 fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n"));
336 }
337 if (detach_auto) {
338 if (gc_before_repack())
339 return -1;
340 /*
341 * failure to daemonize is ok, we'll continue
342 * in foreground
343 */
344 daemonize();
345 }
346 } else
347 add_repack_all_option();
348
349 name = lock_repo_for_gc(force, &pid);
350 if (name) {
351 if (auto_gc)
352 return 0; /* be quiet on --auto */
353 die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
354 name, (uintmax_t)pid);
355 }
356
357 if (gc_before_repack())
358 return -1;
359
360 if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
361 return error(FAILED_RUN, repack.argv[0]);
362
363 if (prune_expire) {
364 argv_array_push(&prune, prune_expire);
365 if (quiet)
366 argv_array_push(&prune, "--no-progress");
367 if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
368 return error(FAILED_RUN, prune.argv[0]);
369 }
370
371 if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
372 return error(FAILED_RUN, rerere.argv[0]);
373
374 if (auto_gc && too_many_loose_objects())
375 warning(_("There are too many unreachable loose objects; "
376 "run 'git prune' to remove them."));
377
378 return 0;
379 }