Merge branch 'rs/alloc-ref'
[git/dscho.git] / builtin-gc.c
blob7af65bb31bfbf3e9a0e47901d44168389d736d20
1 /*
2 * git gc builtin command
4 * Cleanup unreachable files and optimize the repository.
6 * Copyright (c) 2007 James Bowes
8 * Based on git-gc.sh, which is
10 * Copyright (c) 2006 Shawn O. Pearce
13 #include "builtin.h"
14 #include "cache.h"
15 #include "parse-options.h"
16 #include "run-command.h"
18 #define FAILED_RUN "failed to run %s"
20 static const char * const builtin_gc_usage[] = {
21 "git gc [options]",
22 NULL
25 static int pack_refs = 1;
26 static int aggressive_window = -1;
27 static int gc_auto_threshold = 6700;
28 static int gc_auto_pack_limit = 50;
29 static const char *prune_expire = "2.weeks.ago";
31 #define MAX_ADD 10
32 static const char *argv_pack_refs[] = {"pack-refs", "--all", "--prune", NULL};
33 static const char *argv_reflog[] = {"reflog", "expire", "--all", NULL};
34 static const char *argv_repack[MAX_ADD] = {"repack", "-d", "-l", NULL};
35 static const char *argv_prune[] = {"prune", "--expire", NULL, NULL};
36 static const char *argv_rerere[] = {"rerere", "gc", NULL};
38 static int gc_config(const char *var, const char *value, void *cb)
40 if (!strcmp(var, "gc.packrefs")) {
41 if (value && !strcmp(value, "notbare"))
42 pack_refs = -1;
43 else
44 pack_refs = git_config_bool(var, value);
45 return 0;
47 if (!strcmp(var, "gc.aggressivewindow")) {
48 aggressive_window = git_config_int(var, value);
49 return 0;
51 if (!strcmp(var, "gc.auto")) {
52 gc_auto_threshold = git_config_int(var, value);
53 return 0;
55 if (!strcmp(var, "gc.autopacklimit")) {
56 gc_auto_pack_limit = git_config_int(var, value);
57 return 0;
59 if (!strcmp(var, "gc.pruneexpire")) {
60 if (value && strcmp(value, "now")) {
61 unsigned long now = approxidate("now");
62 if (approxidate(value) >= now)
63 return error("Invalid %s: '%s'", var, value);
65 return git_config_string(&prune_expire, var, value);
67 return git_default_config(var, value, cb);
70 static void append_option(const char **cmd, const char *opt, int max_length)
72 int i;
74 for (i = 0; cmd[i]; i++)
77 if (i + 2 >= max_length)
78 die("Too many options specified");
79 cmd[i++] = opt;
80 cmd[i] = NULL;
83 static int too_many_loose_objects(void)
86 * Quickly check if a "gc" is needed, by estimating how
87 * many loose objects there are. Because SHA-1 is evenly
88 * distributed, we can check only one and get a reasonable
89 * estimate.
91 char path[PATH_MAX];
92 const char *objdir = get_object_directory();
93 DIR *dir;
94 struct dirent *ent;
95 int auto_threshold;
96 int num_loose = 0;
97 int needed = 0;
99 if (gc_auto_threshold <= 0)
100 return 0;
102 if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) {
103 warning("insanely long object directory %.*s", 50, objdir);
104 return 0;
106 dir = opendir(path);
107 if (!dir)
108 return 0;
110 auto_threshold = (gc_auto_threshold + 255) / 256;
111 while ((ent = readdir(dir)) != NULL) {
112 if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
113 ent->d_name[38] != '\0')
114 continue;
115 if (++num_loose > auto_threshold) {
116 needed = 1;
117 break;
120 closedir(dir);
121 return needed;
124 static int too_many_packs(void)
126 struct packed_git *p;
127 int cnt;
129 if (gc_auto_pack_limit <= 0)
130 return 0;
132 prepare_packed_git();
133 for (cnt = 0, p = packed_git; p; p = p->next) {
134 char path[PATH_MAX];
135 size_t len;
136 int keep;
138 if (!p->pack_local)
139 continue;
140 len = strlen(p->pack_name);
141 if (PATH_MAX <= len + 1)
142 continue; /* oops, give up */
143 memcpy(path, p->pack_name, len-5);
144 memcpy(path + len - 5, ".keep", 6);
145 keep = access(p->pack_name, F_OK) && (errno == ENOENT);
146 if (keep)
147 continue;
149 * Perhaps check the size of the pack and count only
150 * very small ones here?
152 cnt++;
154 return gc_auto_pack_limit <= cnt;
157 static int run_hook(void)
159 const char *argv[2];
160 struct child_process hook;
161 int ret;
163 argv[0] = git_path("hooks/pre-auto-gc");
164 argv[1] = NULL;
166 if (access(argv[0], X_OK) < 0)
167 return 0;
169 memset(&hook, 0, sizeof(hook));
170 hook.argv = argv;
171 hook.no_stdin = 1;
172 hook.stdout_to_stderr = 1;
174 ret = start_command(&hook);
175 if (ret) {
176 warning("Could not spawn %s", argv[0]);
177 return ret;
179 ret = finish_command(&hook);
180 if (ret == -ERR_RUN_COMMAND_WAITPID_SIGNAL)
181 warning("%s exited due to uncaught signal", argv[0]);
182 return ret;
185 static int need_to_gc(void)
188 * Setting gc.auto to 0 or negative can disable the
189 * automatic gc.
191 if (gc_auto_threshold <= 0)
192 return 0;
195 * If there are too many loose objects, but not too many
196 * packs, we run "repack -d -l". If there are too many packs,
197 * we run "repack -A -d -l". Otherwise we tell the caller
198 * there is no need.
200 if (too_many_packs())
201 append_option(argv_repack, "-A", MAX_ADD);
202 else if (!too_many_loose_objects())
203 return 0;
205 if (run_hook())
206 return 0;
207 return 1;
210 int cmd_gc(int argc, const char **argv, const char *prefix)
212 int prune = 0;
213 int aggressive = 0;
214 int auto_gc = 0;
215 int quiet = 0;
216 char buf[80];
218 struct option builtin_gc_options[] = {
219 OPT_BOOLEAN(0, "prune", &prune, "prune unreferenced objects (deprecated)"),
220 OPT_BOOLEAN(0, "aggressive", &aggressive, "be more thorough (increased runtime)"),
221 OPT_BOOLEAN(0, "auto", &auto_gc, "enable auto-gc mode"),
222 OPT_BOOLEAN('q', "quiet", &quiet, "suppress progress reports"),
223 OPT_END()
226 git_config(gc_config, NULL);
228 if (pack_refs < 0)
229 pack_refs = !is_bare_repository();
231 argc = parse_options(argc, argv, builtin_gc_options, builtin_gc_usage, 0);
232 if (argc > 0)
233 usage_with_options(builtin_gc_usage, builtin_gc_options);
235 if (aggressive) {
236 append_option(argv_repack, "-f", MAX_ADD);
237 if (aggressive_window > 0) {
238 sprintf(buf, "--window=%d", aggressive_window);
239 append_option(argv_repack, buf, MAX_ADD);
242 if (quiet)
243 append_option(argv_repack, "-q", MAX_ADD);
245 if (auto_gc) {
247 * Auto-gc should be least intrusive as possible.
249 if (!need_to_gc())
250 return 0;
251 fprintf(stderr, "Auto packing your repository for optimum "
252 "performance. You may also\n"
253 "run \"git gc\" manually. See "
254 "\"git help gc\" for more information.\n");
255 } else
256 append_option(argv_repack, "-A", MAX_ADD);
258 if (pack_refs && run_command_v_opt(argv_pack_refs, RUN_GIT_CMD))
259 return error(FAILED_RUN, argv_pack_refs[0]);
261 if (run_command_v_opt(argv_reflog, RUN_GIT_CMD))
262 return error(FAILED_RUN, argv_reflog[0]);
264 if (run_command_v_opt(argv_repack, RUN_GIT_CMD))
265 return error(FAILED_RUN, argv_repack[0]);
267 argv_prune[2] = prune_expire;
268 if (run_command_v_opt(argv_prune, RUN_GIT_CMD))
269 return error(FAILED_RUN, argv_prune[0]);
271 if (run_command_v_opt(argv_rerere, RUN_GIT_CMD))
272 return error(FAILED_RUN, argv_rerere[0]);
274 if (auto_gc && too_many_loose_objects())
275 warning("There are too many unreachable loose objects; "
276 "run 'git prune' to remove them.");
278 return 0;