Merge branch 'jk/rev-list-no-bitmap-while-pruning'
[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 "lockfile.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 static const char *prune_worktrees_expire = "3.months.ago";
37
38 static struct argv_array pack_refs_cmd = ARGV_ARRAY_INIT;
39 static struct argv_array reflog = ARGV_ARRAY_INIT;
40 static struct argv_array repack = ARGV_ARRAY_INIT;
41 static struct argv_array prune = ARGV_ARRAY_INIT;
42 static struct argv_array prune_worktrees = ARGV_ARRAY_INIT;
43 static struct argv_array rerere = ARGV_ARRAY_INIT;
44
45 static char *pidfile;
46
47 static void remove_pidfile(void)
48 {
49         if (pidfile)
50                 unlink(pidfile);
51 }
52
53 static void remove_pidfile_on_signal(int signo)
54 {
55         remove_pidfile();
56         sigchain_pop(signo);
57         raise(signo);
58 }
59
60 static void git_config_date_string(const char *key, const char **output)
61 {
62         if (git_config_get_string_const(key, output))
63                 return;
64         if (strcmp(*output, "now")) {
65                 unsigned long now = approxidate("now");
66                 if (approxidate(*output) >= now)
67                         git_die_config(key, _("Invalid %s: '%s'"), key, *output);
68         }
69 }
70
71 static void gc_config(void)
72 {
73         const char *value;
74
75         if (!git_config_get_value("gc.packrefs", &value)) {
76                 if (value && !strcmp(value, "notbare"))
77                         pack_refs = -1;
78                 else
79                         pack_refs = git_config_bool("gc.packrefs", value);
80         }
81
82         git_config_get_int("gc.aggressivewindow", &aggressive_window);
83         git_config_get_int("gc.aggressivedepth", &aggressive_depth);
84         git_config_get_int("gc.auto", &gc_auto_threshold);
85         git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
86         git_config_get_bool("gc.autodetach", &detach_auto);
87         git_config_date_string("gc.pruneexpire", &prune_expire);
88         git_config_date_string("gc.pruneworktreesexpire", &prune_worktrees_expire);
89         git_config(git_default_config, NULL);
90 }
91
92 static int too_many_loose_objects(void)
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
108         if (gc_auto_threshold <= 0)
109                 return 0;
110
111         if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) {
112                 warning(_("insanely long object directory %.*s"), 50, objdir);
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
133 static 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) {
143                 if (!p->pack_local)
144                         continue;
145                 if (p->pack_keep)
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
156 static void add_repack_all_option(void)
157 {
158         if (prune_expire && !strcmp(prune_expire, "now"))
159                 argv_array_push(&repack, "-a");
160         else {
161                 argv_array_push(&repack, "-A");
162                 if (prune_expire)
163                         argv_array_pushf(&repack, "--unpack-unreachable=%s", prune_expire);
164         }
165 }
166
167 static int need_to_gc(void)
168 {
169         /*
170          * Setting gc.auto to 0 or negative can disable the
171          * automatic gc.
172          */
173         if (gc_auto_threshold <= 0)
174                 return 0;
175
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          */
182         if (too_many_packs())
183                 add_repack_all_option();
184         else if (!too_many_loose_objects())
185                 return 0;
186
187         if (run_hook_le(NULL, "pre-auto-gc", NULL))
188                 return 0;
189         return 1;
190 }
191
192 /* return NULL on success, else hostname running the gc */
193 static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
194 {
195         static struct lock_file lock;
196         char my_host[128];
197         struct strbuf sb = STRBUF_INIT;
198         struct stat st;
199         uintmax_t pid;
200         FILE *fp;
201         int fd;
202
203         if (pidfile)
204                 /* already locked */
205                 return NULL;
206
207         if (gethostname(my_host, sizeof(my_host)))
208                 strcpy(my_host, "unknown");
209
210         fd = hold_lock_file_for_update(&lock, git_path("gc.pid"),
211                                        LOCK_DIE_ON_ERROR);
212         if (!force) {
213                 static char locking_host[128];
214                 int should_exit;
215                 fp = fopen(git_path("gc.pid"), "r");
216                 memset(locking_host, 0, sizeof(locking_host));
217                 should_exit =
218                         fp != NULL &&
219                         !fstat(fileno(fp), &st) &&
220                         /*
221                          * 12 hour limit is very generous as gc should
222                          * never take that long. On the other hand we
223                          * don't really need a strict limit here,
224                          * running gc --auto one day late is not a big
225                          * problem. --force can be used in manual gc
226                          * after the user verifies that no gc is
227                          * running.
228                          */
229                         time(NULL) - st.st_mtime <= 12 * 3600 &&
230                         fscanf(fp, "%"PRIuMAX" %127c", &pid, locking_host) == 2 &&
231                         /* be gentle to concurrent "gc" on remote hosts */
232                         (strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM);
233                 if (fp != NULL)
234                         fclose(fp);
235                 if (should_exit) {
236                         if (fd >= 0)
237                                 rollback_lock_file(&lock);
238                         *ret_pid = pid;
239                         return locking_host;
240                 }
241         }
242
243         strbuf_addf(&sb, "%"PRIuMAX" %s",
244                     (uintmax_t) getpid(), my_host);
245         write_in_full(fd, sb.buf, sb.len);
246         strbuf_release(&sb);
247         commit_lock_file(&lock);
248
249         pidfile = git_pathdup("gc.pid");
250         sigchain_push_common(remove_pidfile_on_signal);
251         atexit(remove_pidfile);
252
253         return NULL;
254 }
255
256 static int gc_before_repack(void)
257 {
258         if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
259                 return error(FAILED_RUN, pack_refs_cmd.argv[0]);
260
261         if (prune_reflogs && run_command_v_opt(reflog.argv, RUN_GIT_CMD))
262                 return error(FAILED_RUN, reflog.argv[0]);
263
264         pack_refs = 0;
265         prune_reflogs = 0;
266         return 0;
267 }
268
269 int cmd_gc(int argc, const char **argv, const char *prefix)
270 {
271         int aggressive = 0;
272         int auto_gc = 0;
273         int quiet = 0;
274         int force = 0;
275         const char *name;
276         pid_t pid;
277
278         struct option builtin_gc_options[] = {
279                 OPT__QUIET(&quiet, N_("suppress progress reporting")),
280                 { OPTION_STRING, 0, "prune", &prune_expire, N_("date"),
281                         N_("prune unreferenced objects"),
282                         PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire },
283                 OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")),
284                 OPT_BOOL(0, "auto", &auto_gc, N_("enable auto-gc mode")),
285                 OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")),
286                 OPT_END()
287         };
288
289         if (argc == 2 && !strcmp(argv[1], "-h"))
290                 usage_with_options(builtin_gc_usage, builtin_gc_options);
291
292         argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL);
293         argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL);
294         argv_array_pushl(&repack, "repack", "-d", "-l", NULL);
295         argv_array_pushl(&prune, "prune", "--expire", NULL);
296         argv_array_pushl(&prune_worktrees, "prune", "--worktrees", "--expire", NULL);
297         argv_array_pushl(&rerere, "rerere", "gc", NULL);
298
299         gc_config();
300
301         if (pack_refs < 0)
302                 pack_refs = !is_bare_repository();
303
304         argc = parse_options(argc, argv, prefix, builtin_gc_options,
305                              builtin_gc_usage, 0);
306         if (argc > 0)
307                 usage_with_options(builtin_gc_usage, builtin_gc_options);
308
309         if (aggressive) {
310                 argv_array_push(&repack, "-f");
311                 if (aggressive_depth > 0)
312                         argv_array_pushf(&repack, "--depth=%d", aggressive_depth);
313                 if (aggressive_window > 0)
314                         argv_array_pushf(&repack, "--window=%d", aggressive_window);
315         }
316         if (quiet)
317                 argv_array_push(&repack, "-q");
318
319         if (auto_gc) {
320                 /*
321                  * Auto-gc should be least intrusive as possible.
322                  */
323                 if (!need_to_gc())
324                         return 0;
325                 if (!quiet) {
326                         if (detach_auto)
327                                 fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n"));
328                         else
329                                 fprintf(stderr, _("Auto packing the repository for optimum performance.\n"));
330                         fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n"));
331                 }
332                 if (detach_auto) {
333                         if (gc_before_repack())
334                                 return -1;
335                         /*
336                          * failure to daemonize is ok, we'll continue
337                          * in foreground
338                          */
339                         daemonize();
340                 }
341         } else
342                 add_repack_all_option();
343
344         name = lock_repo_for_gc(force, &pid);
345         if (name) {
346                 if (auto_gc)
347                         return 0; /* be quiet on --auto */
348                 die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"),
349                     name, (uintmax_t)pid);
350         }
351
352         if (gc_before_repack())
353                 return -1;
354
355         if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
356                 return error(FAILED_RUN, repack.argv[0]);
357
358         if (prune_expire) {
359                 argv_array_push(&prune, prune_expire);
360                 if (quiet)
361                         argv_array_push(&prune, "--no-progress");
362                 if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
363                         return error(FAILED_RUN, prune.argv[0]);
364         }
365
366         if (prune_worktrees_expire) {
367                 argv_array_push(&prune_worktrees, prune_worktrees_expire);
368                 if (run_command_v_opt(prune_worktrees.argv, RUN_GIT_CMD))
369                         return error(FAILED_RUN, prune_worktrees.argv[0]);
370         }
371
372         if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
373                 return error(FAILED_RUN, rerere.argv[0]);
374
375         if (auto_gc && too_many_loose_objects())
376                 warning(_("There are too many unreachable loose objects; "
377                         "run 'git prune' to remove them."));
378
379         return 0;
380 }