/* * git gc builtin command * * Cleanup unreachable files and optimize the repository. * * Copyright (c) 2007 James Bowes * * Based on git-gc.sh, which is * * Copyright (c) 2006 Shawn O. Pearce */ #include "builtin.h" #include "tempfile.h" #include "lockfile.h" #include "parse-options.h" #include "run-command.h" #include "sigchain.h" #include "argv-array.h" #include "commit.h" #define FAILED_RUN "failed to run %s" static const char * const builtin_gc_usage[] = { N_("git gc []"), NULL }; static int pack_refs = 1; static int prune_reflogs = 1; static int aggressive_depth = 50; static int aggressive_window = 250; static int gc_auto_threshold = 6700; static int gc_auto_pack_limit = 50; static int detach_auto = 1; static const char *prune_expire = "2.weeks.ago"; static const char *prune_worktrees_expire = "3.months.ago"; static struct argv_array pack_refs_cmd = ARGV_ARRAY_INIT; static struct argv_array reflog = ARGV_ARRAY_INIT; static struct argv_array repack = ARGV_ARRAY_INIT; static struct argv_array prune = ARGV_ARRAY_INIT; static struct argv_array prune_worktrees = ARGV_ARRAY_INIT; static struct argv_array rerere = ARGV_ARRAY_INIT; static struct tempfile pidfile; static struct lock_file log_lock; static struct string_list pack_garbage = STRING_LIST_INIT_DUP; static void clean_pack_garbage(void) { int i; for (i = 0; i < pack_garbage.nr; i++) unlink_or_warn(pack_garbage.items[i].string); string_list_clear(&pack_garbage, 0); } static void report_pack_garbage(unsigned seen_bits, const char *path) { if (seen_bits == PACKDIR_FILE_IDX) string_list_append(&pack_garbage, path); } static void process_log_file(void) { struct stat st; if (!fstat(get_lock_file_fd(&log_lock), &st) && st.st_size) commit_lock_file(&log_lock); else rollback_lock_file(&log_lock); } static void process_log_file_at_exit(void) { fflush(stderr); process_log_file(); } static void process_log_file_on_signal(int signo) { process_log_file(); sigchain_pop(signo); raise(signo); } static void gc_config(void) { const char *value; if (!git_config_get_value("gc.packrefs", &value)) { if (value && !strcmp(value, "notbare")) pack_refs = -1; else pack_refs = git_config_bool("gc.packrefs", value); } git_config_get_int("gc.aggressivewindow", &aggressive_window); git_config_get_int("gc.aggressivedepth", &aggressive_depth); git_config_get_int("gc.auto", &gc_auto_threshold); git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit); git_config_get_bool("gc.autodetach", &detach_auto); git_config_get_expiry("gc.pruneexpire", &prune_expire); git_config_get_expiry("gc.worktreepruneexpire", &prune_worktrees_expire); git_config(git_default_config, NULL); } static int too_many_loose_objects(void) { /* * Quickly check if a "gc" is needed, by estimating how * many loose objects there are. Because SHA-1 is evenly * distributed, we can check only one and get a reasonable * estimate. */ char path[PATH_MAX]; const char *objdir = get_object_directory(); DIR *dir; struct dirent *ent; int auto_threshold; int num_loose = 0; int needed = 0; if (gc_auto_threshold <= 0) return 0; if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) { warning(_("insanely long object directory %.*s"), 50, objdir); return 0; } dir = opendir(path); if (!dir) return 0; auto_threshold = (gc_auto_threshold + 255) / 256; while ((ent = readdir(dir)) != NULL) { if (strspn(ent->d_name, "0123456789abcdef") != 38 || ent->d_name[38] != '\0') continue; if (++num_loose > auto_threshold) { needed = 1; break; } } closedir(dir); return needed; } static int too_many_packs(void) { struct packed_git *p; int cnt; if (gc_auto_pack_limit <= 0) return 0; prepare_packed_git(); for (cnt = 0, p = packed_git; p; p = p->next) { if (!p->pack_local) continue; if (p->pack_keep) continue; /* * Perhaps check the size of the pack and count only * very small ones here? */ cnt++; } return gc_auto_pack_limit < cnt; } static void add_repack_all_option(void) { if (prune_expire && !strcmp(prune_expire, "now")) argv_array_push(&repack, "-a"); else { argv_array_push(&repack, "-A"); if (prune_expire) argv_array_pushf(&repack, "--unpack-unreachable=%s", prune_expire); } } static int need_to_gc(void) { /* * Setting gc.auto to 0 or negative can disable the * automatic gc. */ if (gc_auto_threshold <= 0) return 0; /* * If there are too many loose objects, but not too many * packs, we run "repack -d -l". If there are too many packs, * we run "repack -A -d -l". Otherwise we tell the caller * there is no need. */ if (too_many_packs()) add_repack_all_option(); else if (!too_many_loose_objects()) return 0; if (run_hook_le(NULL, "pre-auto-gc", NULL)) return 0; return 1; } /* return NULL on success, else hostname running the gc */ static const char *lock_repo_for_gc(int force, pid_t* ret_pid) { static struct lock_file lock; char my_host[128]; struct strbuf sb = STRBUF_INIT; struct stat st; uintmax_t pid; FILE *fp; int fd; char *pidfile_path; if (is_tempfile_active(&pidfile)) /* already locked */ return NULL; if (gethostname(my_host, sizeof(my_host))) xsnprintf(my_host, sizeof(my_host), "unknown"); pidfile_path = git_pathdup("gc.pid"); fd = hold_lock_file_for_update(&lock, pidfile_path, LOCK_DIE_ON_ERROR); if (!force) { static char locking_host[128]; int should_exit; fp = fopen(pidfile_path, "r"); memset(locking_host, 0, sizeof(locking_host)); should_exit = fp != NULL && !fstat(fileno(fp), &st) && /* * 12 hour limit is very generous as gc should * never take that long. On the other hand we * don't really need a strict limit here, * running gc --auto one day late is not a big * problem. --force can be used in manual gc * after the user verifies that no gc is * running. */ time(NULL) - st.st_mtime <= 12 * 3600 && fscanf(fp, "%"SCNuMAX" %127c", &pid, locking_host) == 2 && /* be gentle to concurrent "gc" on remote hosts */ (strcmp(locking_host, my_host) || !kill(pid, 0) || errno == EPERM); if (fp != NULL) fclose(fp); if (should_exit) { if (fd >= 0) rollback_lock_file(&lock); *ret_pid = pid; free(pidfile_path); return locking_host; } } strbuf_addf(&sb, "%"PRIuMAX" %s", (uintmax_t) getpid(), my_host); write_in_full(fd, sb.buf, sb.len); strbuf_release(&sb); commit_lock_file(&lock); register_tempfile(&pidfile, pidfile_path); free(pidfile_path); return NULL; } static int report_last_gc_error(void) { struct strbuf sb = STRBUF_INIT; int ret; ret = strbuf_read_file(&sb, git_path("gc.log"), 0); if (ret > 0) return error(_("The last gc run reported the following. " "Please correct the root cause\n" "and remove %s.\n" "Automatic cleanup will not be performed " "until the file is removed.\n\n" "%s"), git_path("gc.log"), sb.buf); strbuf_release(&sb); return 0; } static int gc_before_repack(void) { if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD)) return error(FAILED_RUN, pack_refs_cmd.argv[0]); if (prune_reflogs && run_command_v_opt(reflog.argv, RUN_GIT_CMD)) return error(FAILED_RUN, reflog.argv[0]); pack_refs = 0; prune_reflogs = 0; return 0; } int cmd_gc(int argc, const char **argv, const char *prefix) { int aggressive = 0; int auto_gc = 0; int quiet = 0; int force = 0; const char *name; pid_t pid; int daemonized = 0; struct option builtin_gc_options[] = { OPT__QUIET(&quiet, N_("suppress progress reporting")), { OPTION_STRING, 0, "prune", &prune_expire, N_("date"), N_("prune unreferenced objects"), PARSE_OPT_OPTARG, NULL, (intptr_t)prune_expire }, OPT_BOOL(0, "aggressive", &aggressive, N_("be more thorough (increased runtime)")), OPT_BOOL(0, "auto", &auto_gc, N_("enable auto-gc mode")), OPT_BOOL(0, "force", &force, N_("force running gc even if there may be another gc running")), OPT_END() }; if (argc == 2 && !strcmp(argv[1], "-h")) usage_with_options(builtin_gc_usage, builtin_gc_options); argv_array_pushl(&pack_refs_cmd, "pack-refs", "--all", "--prune", NULL); argv_array_pushl(&reflog, "reflog", "expire", "--all", NULL); argv_array_pushl(&repack, "repack", "-d", "-l", NULL); argv_array_pushl(&prune, "prune", "--expire", NULL); argv_array_pushl(&prune_worktrees, "worktree", "prune", "--expire", NULL); argv_array_pushl(&rerere, "rerere", "gc", NULL); gc_config(); if (pack_refs < 0) pack_refs = !is_bare_repository(); argc = parse_options(argc, argv, prefix, builtin_gc_options, builtin_gc_usage, 0); if (argc > 0) usage_with_options(builtin_gc_usage, builtin_gc_options); if (aggressive) { argv_array_push(&repack, "-f"); if (aggressive_depth > 0) argv_array_pushf(&repack, "--depth=%d", aggressive_depth); if (aggressive_window > 0) argv_array_pushf(&repack, "--window=%d", aggressive_window); } if (quiet) argv_array_push(&repack, "-q"); if (auto_gc) { /* * Auto-gc should be least intrusive as possible. */ if (!need_to_gc()) return 0; if (!quiet) { if (detach_auto) fprintf(stderr, _("Auto packing the repository in background for optimum performance.\n")); else fprintf(stderr, _("Auto packing the repository for optimum performance.\n")); fprintf(stderr, _("See \"git help gc\" for manual housekeeping.\n")); } if (detach_auto) { if (report_last_gc_error()) return -1; if (gc_before_repack()) return -1; /* * failure to daemonize is ok, we'll continue * in foreground */ daemonized = !daemonize(); } } else add_repack_all_option(); name = lock_repo_for_gc(force, &pid); if (name) { if (auto_gc) return 0; /* be quiet on --auto */ die(_("gc is already running on machine '%s' pid %"PRIuMAX" (use --force if not)"), name, (uintmax_t)pid); } if (daemonized) { hold_lock_file_for_update(&log_lock, git_path("gc.log"), LOCK_DIE_ON_ERROR); dup2(get_lock_file_fd(&log_lock), 2); sigchain_push_common(process_log_file_on_signal); atexit(process_log_file_at_exit); } if (gc_before_repack()) return -1; if (!repository_format_precious_objects) { if (run_command_v_opt(repack.argv, RUN_GIT_CMD)) return error(FAILED_RUN, repack.argv[0]); if (prune_expire) { argv_array_push(&prune, prune_expire); if (quiet) argv_array_push(&prune, "--no-progress"); if (run_command_v_opt(prune.argv, RUN_GIT_CMD)) return error(FAILED_RUN, prune.argv[0]); } } if (prune_worktrees_expire) { argv_array_push(&prune_worktrees, prune_worktrees_expire); if (run_command_v_opt(prune_worktrees.argv, RUN_GIT_CMD)) return error(FAILED_RUN, prune_worktrees.argv[0]); } if (run_command_v_opt(rerere.argv, RUN_GIT_CMD)) return error(FAILED_RUN, rerere.argv[0]); report_garbage = report_pack_garbage; reprepare_packed_git(); if (pack_garbage.nr > 0) clean_pack_garbage(); if (auto_gc && too_many_loose_objects()) warning(_("There are too many unreachable loose objects; " "run 'git prune' to remove them.")); return 0; }