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