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