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
15 #include "run-command.h"
17 #define FAILED_RUN "failed to run %s"
19 static const char builtin_gc_usage[] = "git-gc [--prune] [--aggressive]";
21 static int pack_refs = 1;
22 static int aggressive_window = -1;
23 static int gc_auto_threshold = 6700;
24 static int gc_auto_pack_limit = 20;
27 static const char *argv_pack_refs[] = {"pack-refs", "--all", "--prune", NULL};
28 static const char *argv_reflog[] = {"reflog", "expire", "--all", NULL};
29 static const char *argv_repack[MAX_ADD] = {"repack", "-d", "-l", NULL};
30 static const char *argv_prune[] = {"prune", NULL};
31 static const char *argv_rerere[] = {"rerere", "gc", NULL};
33 static int gc_config(const char *var, const char *value)
35 if (!strcmp(var, "gc.packrefs")) {
36 if (!strcmp(value, "notbare"))
39 pack_refs = git_config_bool(var, value);
42 if (!strcmp(var, "gc.aggressivewindow")) {
43 aggressive_window = git_config_int(var, value);
46 if (!strcmp(var, "gc.auto")) {
47 gc_auto_threshold = git_config_int(var, value);
50 if (!strcmp(var, "gc.autopacklimit")) {
51 gc_auto_pack_limit = git_config_int(var, value);
54 return git_default_config(var, value);
57 static void append_option(const char **cmd, const char *opt, int max_length)
61 for (i = 0; cmd[i]; i++)
64 if (i + 2 >= max_length)
65 die("Too many options specified");
70 static int too_many_loose_objects(void)
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
79 const char *objdir = get_object_directory();
86 if (gc_auto_threshold <= 0)
89 if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) {
90 warning("insanely long object directory %.*s", 50, objdir);
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')
102 if (++num_loose > auto_threshold) {
111 static int too_many_packs(void)
113 struct packed_git *p;
116 if (gc_auto_pack_limit <= 0)
119 prepare_packed_git();
120 for (cnt = 0, p = packed_git; p; p = p->next) {
127 len = strlen(p->pack_name);
128 if (PATH_MAX <= len + 1)
129 continue; /* oops, give up */
130 memcpy(path, p->pack_name, len-5);
131 memcpy(path + len - 5, ".keep", 6);
132 keep = access(p->pack_name, F_OK) && (errno == ENOENT);
136 * Perhaps check the size of the pack and count only
137 * very small ones here?
141 return gc_auto_pack_limit <= cnt;
144 static int need_to_gc(void)
147 * Setting gc.auto and gc.autopacklimit to 0 or negative can
148 * disable the automatic gc.
150 if (gc_auto_threshold <= 0 && gc_auto_pack_limit <= 0)
154 * If there are too many loose objects, but not too many
155 * packs, we run "repack -d -l". If there are too many packs,
156 * we run "repack -A -d -l". Otherwise we tell the caller
159 if (too_many_packs())
160 append_option(argv_repack, "-A", MAX_ADD);
161 else if (!too_many_loose_objects())
166 int cmd_gc(int argc, const char **argv, const char *prefix)
173 git_config(gc_config);
176 pack_refs = !is_bare_repository();
178 for (i = 1; i < argc; i++) {
179 const char *arg = argv[i];
180 if (!strcmp(arg, "--prune")) {
184 if (!strcmp(arg, "--aggressive")) {
185 append_option(argv_repack, "-f", MAX_ADD);
186 if (aggressive_window > 0) {
187 sprintf(buf, "--window=%d", aggressive_window);
188 append_option(argv_repack, buf, MAX_ADD);
192 if (!strcmp(arg, "--auto")) {
199 usage(builtin_gc_usage);
203 * Auto-gc should be least intrusive as possible.
208 fprintf(stderr, "Packing your repository for optimum "
209 "performance. You may also\n"
210 "run \"git gc\" manually. See "
211 "\"git help gc\" for more information.\n");
214 * Use safer (for shared repos) "-A" option to
215 * repack when not pruning. Auto-gc makes its
219 append_option(argv_repack, "-a", MAX_ADD);
221 append_option(argv_repack, "-A", MAX_ADD);
224 if (pack_refs && run_command_v_opt(argv_pack_refs, RUN_GIT_CMD))
225 return error(FAILED_RUN, argv_pack_refs[0]);
227 if (run_command_v_opt(argv_reflog, RUN_GIT_CMD))
228 return error(FAILED_RUN, argv_reflog[0]);
230 if (run_command_v_opt(argv_repack, RUN_GIT_CMD))
231 return error(FAILED_RUN, argv_repack[0]);
233 if (prune && run_command_v_opt(argv_prune, RUN_GIT_CMD))
234 return error(FAILED_RUN, argv_prune[0]);
236 if (run_command_v_opt(argv_rerere, RUN_GIT_CMD))
237 return error(FAILED_RUN, argv_rerere[0]);
239 if (auto_gc && too_many_loose_objects())
240 warning("There are too many unreachable loose objects; "
241 "run 'git prune' to remove them.");