gc: reject if another gc is running, unless --force is given
[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"
234587fc 17#include "argv-array.h"
6757ada4
JB
18
19#define FAILED_RUN "failed to run %s"
20
44c637c8 21static const char * const builtin_gc_usage[] = {
6705c162 22 N_("git gc [options]"),
44c637c8
JB
23 NULL
24};
6757ada4 25
56752391 26static int pack_refs = 1;
1c192f34 27static int aggressive_window = 250;
2c3c4399 28static int gc_auto_threshold = 6700;
97063974 29static int gc_auto_pack_limit = 50;
d3154b44 30static const char *prune_expire = "2.weeks.ago";
6757ada4 31
234587fc
JK
32static struct argv_array pack_refs_cmd = ARGV_ARRAY_INIT;
33static struct argv_array reflog = ARGV_ARRAY_INIT;
34static struct argv_array repack = ARGV_ARRAY_INIT;
35static struct argv_array prune = ARGV_ARRAY_INIT;
36static struct argv_array rerere = ARGV_ARRAY_INIT;
6757ada4 37
ef90d6d4 38static int gc_config(const char *var, const char *value, void *cb)
6757ada4
JB
39{
40 if (!strcmp(var, "gc.packrefs")) {
c5e5a2c0 41 if (value && !strcmp(value, "notbare"))
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JB
42 pack_refs = -1;
43 else
44 pack_refs = git_config_bool(var, value);
45 return 0;
46 }
0d7566a5
TT
47 if (!strcmp(var, "gc.aggressivewindow")) {
48 aggressive_window = git_config_int(var, value);
49 return 0;
50 }
2c3c4399
JH
51 if (!strcmp(var, "gc.auto")) {
52 gc_auto_threshold = git_config_int(var, value);
53 return 0;
54 }
17815501
JH
55 if (!strcmp(var, "gc.autopacklimit")) {
56 gc_auto_pack_limit = git_config_int(var, value);
57 return 0;
58 }
25ee9731 59 if (!strcmp(var, "gc.pruneexpire")) {
d3154b44 60 if (value && strcmp(value, "now")) {
25ee9731
JS
61 unsigned long now = approxidate("now");
62 if (approxidate(value) >= now)
fea6128b 63 return error(_("Invalid %s: '%s'"), var, value);
25ee9731 64 }
d3154b44 65 return git_config_string(&prune_expire, var, value);
25ee9731 66 }
ef90d6d4 67 return git_default_config(var, value, cb);
6757ada4
JB
68}
69
a087cc98 70static int too_many_loose_objects(void)
2c3c4399
JH
71{
72 /*
73 * Quickly check if a "gc" is needed, by estimating how
74 * many loose objects there are. Because SHA-1 is evenly
75 * distributed, we can check only one and get a reasonable
76 * estimate.
77 */
78 char path[PATH_MAX];
79 const char *objdir = get_object_directory();
80 DIR *dir;
81 struct dirent *ent;
82 int auto_threshold;
83 int num_loose = 0;
84 int needed = 0;
85
17815501
JH
86 if (gc_auto_threshold <= 0)
87 return 0;
88
2c3c4399 89 if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) {
fea6128b 90 warning(_("insanely long object directory %.*s"), 50, objdir);
2c3c4399
JH
91 return 0;
92 }
93 dir = opendir(path);
94 if (!dir)
95 return 0;
96
97 auto_threshold = (gc_auto_threshold + 255) / 256;
98 while ((ent = readdir(dir)) != NULL) {
99 if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
100 ent->d_name[38] != '\0')
101 continue;
102 if (++num_loose > auto_threshold) {
103 needed = 1;
104 break;
105 }
106 }
107 closedir(dir);
108 return needed;
109}
110
17815501
JH
111static int too_many_packs(void)
112{
113 struct packed_git *p;
114 int cnt;
115
116 if (gc_auto_pack_limit <= 0)
117 return 0;
118
119 prepare_packed_git();
120 for (cnt = 0, p = packed_git; p; p = p->next) {
17815501
JH
121 if (!p->pack_local)
122 continue;
01af249f 123 if (p->pack_keep)
17815501
JH
124 continue;
125 /*
126 * Perhaps check the size of the pack and count only
127 * very small ones here?
128 */
129 cnt++;
130 }
131 return gc_auto_pack_limit <= cnt;
132}
133
7e52f566
JK
134static void add_repack_all_option(void)
135{
136 if (prune_expire && !strcmp(prune_expire, "now"))
234587fc 137 argv_array_push(&repack, "-a");
7e52f566 138 else {
234587fc
JK
139 argv_array_push(&repack, "-A");
140 if (prune_expire)
141 argv_array_pushf(&repack, "--unpack-unreachable=%s", prune_expire);
7e52f566
JK
142 }
143}
144
a087cc98
JH
145static int need_to_gc(void)
146{
147 /*
b14d255b
BC
148 * Setting gc.auto to 0 or negative can disable the
149 * automatic gc.
a087cc98 150 */
b14d255b 151 if (gc_auto_threshold <= 0)
95143f9e
JH
152 return 0;
153
17815501
JH
154 /*
155 * If there are too many loose objects, but not too many
156 * packs, we run "repack -d -l". If there are too many packs,
157 * we run "repack -A -d -l". Otherwise we tell the caller
158 * there is no need.
159 */
17815501 160 if (too_many_packs())
7e52f566 161 add_repack_all_option();
17815501
JH
162 else if (!too_many_loose_objects())
163 return 0;
bde30540 164
ae98a008 165 if (run_hook(NULL, "pre-auto-gc", NULL))
bde30540 166 return 0;
95143f9e 167 return 1;
a087cc98
JH
168}
169
64a99eb4
NTND
170/* return NULL on success, else hostname running the gc */
171static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
172{
173 static struct lock_file lock;
174 static char locking_host[128];
175 char my_host[128];
176 struct strbuf sb = STRBUF_INIT;
177 struct stat st;
178 uintmax_t pid;
179 FILE *fp;
180 int fd, should_exit;
181
182 if (gethostname(my_host, sizeof(my_host)))
183 strcpy(my_host, "unknown");
184
185 fd = hold_lock_file_for_update(&lock, git_path("gc.pid"),
186 LOCK_DIE_ON_ERROR);
187 if (!force) {
188 fp = fopen(git_path("gc.pid"), "r");
189 memset(locking_host, 0, sizeof(locking_host));
190 should_exit =
191 fp != NULL &&
192 !fstat(fileno(fp), &st) &&
193 /*
194 * 12 hour limit is very generous as gc should
195 * never take that long. On the other hand we
196 * don't really need a strict limit here,
197 * running gc --auto one day late is not a big
198 * problem. --force can be used in manual gc
199 * after the user verifies that no gc is
200 * running.
201 */
202 time(NULL) - st.st_mtime <= 12 * 3600 &&
203 fscanf(fp, "%"PRIuMAX" %127c", &pid, locking_host) == 2 &&
204 /* be gentle to concurrent "gc" on remote hosts */
205 (strcmp(locking_host, my_host) || !kill(pid, 0));
206 if (fp != NULL)
207 fclose(fp);
208 if (should_exit) {
209 if (fd >= 0)
210 rollback_lock_file(&lock);
211 *ret_pid = pid;
212 return locking_host;
213 }
214 }
215
216 strbuf_addf(&sb, "%"PRIuMAX" %s",
217 (uintmax_t) getpid(), my_host);
218 write_in_full(fd, sb.buf, sb.len);
219 strbuf_release(&sb);
220 commit_lock_file(&lock);
221
222 return NULL;
223}
224
6757ada4
JB
225int cmd_gc(int argc, const char **argv, const char *prefix)
226{
44c637c8 227 int aggressive = 0;
2c3c4399 228 int auto_gc = 0;
a0c14cbb 229 int quiet = 0;
64a99eb4
NTND
230 int force = 0;
231 const char *name;
232 pid_t pid;
6757ada4 233
44c637c8 234 struct option builtin_gc_options[] = {
6705c162
NTND
235 OPT__QUIET(&quiet, N_("suppress progress reporting")),
236 { OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
237 N_("prune unreferenced objects"),
58e9d9d4 238 PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
6705c162
NTND
239 OPT_BOOLEAN(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
240 OPT_BOOLEAN(0, "auto", &auto_gc, N_("enable auto-gc mode")),
64a99eb4 241 OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")),
44c637c8
JB
242 OPT_END()
243 };
244
0c8151b6
NTND
245 if (argc == 2 && !strcmp(argv[1], "-h"))
246 usage_with_options(builtin_gc_usage, builtin_gc_options);
247
234587fc
JK
248 argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
249 argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL);
250 argv_array_pushl(&repack, "repack", "-d", "-l", NULL);
251 argv_array_pushl(&prune, "prune", "--expire", NULL );
252 argv_array_pushl(&rerere, "rerere", "gc", NULL);
253
ef90d6d4 254 git_config(gc_config, NULL);
6757ada4
JB
255
256 if (pack_refs < 0)
257 pack_refs = !is_bare_repository();
258
37782920
SB
259 argc = parse_options(argc, argv, prefix, builtin_gc_options,
260 builtin_gc_usage, 0);
44c637c8
JB
261 if (argc > 0)
262 usage_with_options(builtin_gc_usage, builtin_gc_options);
263
264 if (aggressive) {
234587fc
JK
265 argv_array_push(&repack, "-f");
266 argv_array_push(&repack, "--depth=250");
267 if (aggressive_window > 0)
268 argv_array_pushf(&repack, "--window=%d", aggressive_window);
6757ada4 269 }
a0c14cbb 270 if (quiet)
234587fc 271 argv_array_push(&repack, "-q");
6757ada4 272
2c3c4399
JH
273 if (auto_gc) {
274 /*
275 * Auto-gc should be least intrusive as possible.
276 */
2c3c4399
JH
277 if (!need_to_gc())
278 return 0;
df995c7d 279 if (!quiet)
f6908ae8
ÆAB
280 fprintf(stderr,
281 _("Auto packing the repository for optimum performance. You may also\n"
282 "run \"git gc\" manually. See "
daab4eea 283 "\"git help gc\" for more information.\n"));
a37cce3b 284 } else
7e52f566 285 add_repack_all_option();
2c3c4399 286
64a99eb4
NTND
287 name = lock_repo_for_gc(force, &pid);
288 if (name) {
289 if (auto_gc)
290 return 0; /* be quiet on --auto */
291 die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
292 name, (uintmax_t)pid);
293 }
294
234587fc
JK
295 if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
296 return error(FAILED_RUN, pack_refs_cmd.argv[0]);
6757ada4 297
234587fc
JK
298 if (run_command_v_opt(reflog.argv, RUN_GIT_CMD))
299 return error(FAILED_RUN, reflog.argv[0]);
6757ada4 300
234587fc
JK
301 if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
302 return error(FAILED_RUN, repack.argv[0]);
6757ada4 303
58e9d9d4 304 if (prune_expire) {
234587fc 305 argv_array_push(&prune, prune_expire);
bf0a59b3 306 if (quiet)
234587fc
JK
307 argv_array_push(&prune, "--no-progress");
308 if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
309 return error(FAILED_RUN, prune.argv[0]);
58e9d9d4 310 }
6757ada4 311
234587fc
JK
312 if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
313 return error(FAILED_RUN, rerere.argv[0]);
6757ada4 314
a087cc98 315 if (auto_gc && too_many_loose_objects())
fea6128b
ÆAB
316 warning(_("There are too many unreachable loose objects; "
317 "run 'git prune' to remove them."));
a087cc98 318
6757ada4
JB
319 return 0;
320}