diff options
Diffstat (limited to 'builtin/gc.c')
| -rw-r--r-- | builtin/gc.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/builtin/gc.c b/builtin/gc.c new file mode 100644 index 0000000000..c14190f840 --- /dev/null +++ b/builtin/gc.c @@ -0,0 +1,344 @@ +/* + * 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 "cache.h" +#include "parse-options.h" +#include "run-command.h" +#include "sigchain.h" +#include "argv-array.h" + +#define FAILED_RUN "failed to run %s" + +static const char * const builtin_gc_usage[] = { + N_("git gc [options]"), + NULL +}; + +static int pack_refs = 1; +static int aggressive_window = 250; +static int gc_auto_threshold = 6700; +static int gc_auto_pack_limit = 50; +static const char *prune_expire = "2.weeks.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 rerere = ARGV_ARRAY_INIT; + +static char *pidfile; + +static void remove_pidfile(void) +{ + if (pidfile) + unlink(pidfile); +} + +static void remove_pidfile_on_signal(int signo) +{ + remove_pidfile(); + sigchain_pop(signo); + raise(signo); +} + +static int gc_config(const char *var, const char *value, void *cb) +{ + if (!strcmp(var, "gc.packrefs")) { + if (value && !strcmp(value, "notbare")) + pack_refs = -1; + else + pack_refs = git_config_bool(var, value); + return 0; + } + if (!strcmp(var, "gc.aggressivewindow")) { + aggressive_window = git_config_int(var, value); + return 0; + } + if (!strcmp(var, "gc.auto")) { + gc_auto_threshold = git_config_int(var, value); + return 0; + } + if (!strcmp(var, "gc.autopacklimit")) { + gc_auto_pack_limit = git_config_int(var, value); + return 0; + } + if (!strcmp(var, "gc.pruneexpire")) { + if (value && strcmp(value, "now")) { + unsigned long now = approxidate("now"); + if (approxidate(value) >= now) + return error(_("Invalid %s: '%s'"), var, value); + } + return git_config_string(&prune_expire, var, value); + } + return git_default_config(var, value, cb); +} + +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(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; + static char locking_host[128]; + char my_host[128]; + struct strbuf sb = STRBUF_INIT; + struct stat st; + uintmax_t pid; + FILE *fp; + int fd, should_exit; + + if (pidfile) + /* already locked */ + return NULL; + + if (gethostname(my_host, sizeof(my_host))) + strcpy(my_host, "unknown"); + + fd = hold_lock_file_for_update(&lock, git_path("gc.pid"), + LOCK_DIE_ON_ERROR); + if (!force) { + fp = fopen(git_path("gc.pid"), "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, "%"PRIuMAX" %127c", &pid, locking_host) == 2 && + /* be gentle to concurrent "gc" on remote hosts */ + (strcmp(locking_host, my_host) || !kill(pid, 0)); + if (fp != NULL) + fclose(fp); + if (should_exit) { + if (fd >= 0) + rollback_lock_file(&lock); + *ret_pid = pid; + 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); + + pidfile = git_pathdup("gc.pid"); + sigchain_push_common(remove_pidfile_on_signal); + atexit(remove_pidfile); + + return NULL; +} + +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; + + 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(&rerere, "rerere", "gc", NULL); + + git_config(gc_config, NULL); + + 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"); + argv_array_push(&repack, "--depth=250"); + 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) + fprintf(stderr, + _("Auto packing the repository for optimum performance. You may also\n" + "run \"git gc\" manually. See " + "\"git help gc\" for more information.\n")); + } 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 (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD)) + return error(FAILED_RUN, pack_refs_cmd.argv[0]); + + if (run_command_v_opt(reflog.argv, RUN_GIT_CMD)) + return error(FAILED_RUN, reflog.argv[0]); + + 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 (run_command_v_opt(rerere.argv, RUN_GIT_CMD)) + return error(FAILED_RUN, rerere.argv[0]); + + if (auto_gc && too_many_loose_objects()) + warning(_("There are too many unreachable loose objects; " + "run 'git prune' to remove them.")); + + return 0; +} |