merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

1 files changed, 702 insertions, 0 deletions

diff --git a/third_party/git/builtin/gc.c b/third_party/git/builtin/gc.c
new file mode 100644
index 000000000000..c18efadda53e
--- /dev/null
+++ b/third_party/git/builtin/gc.c
@@ -0,0 +1,702 @@
+/*
+ * 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 "repository.h"
+#include "config.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"
+#include "commit-graph.h"
+#include "packfile.h"
+#include "object-store.h"
+#include "pack.h"
+#include "pack-objects.h"
+#include "blob.h"
+#include "tree.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 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 gc_write_commit_graph;
+static int detach_auto = 1;
+static timestamp_t gc_log_expire_time;
+static const char *gc_log_expire = "1.day.ago";
+static const char *prune_expire = "2.weeks.ago";
+static const char *prune_worktrees_expire = "3.months.ago";
+static unsigned long big_pack_threshold;
+static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
+
+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)) {
+		/*
+		 * Perhaps there was an i/o error or another
+		 * unlikely situation.  Try to make a note of
+		 * this in gc.log along with any existing
+		 * messages.
+		 */
+		int saved_errno = errno;
+		fprintf(stderr, _("Failed to fstat %s: %s"),
+			get_tempfile_path(log_lock.tempfile),
+			strerror(saved_errno));
+		fflush(stderr);
+		commit_lock_file(&log_lock);
+		errno = saved_errno;
+	} else if (st.st_size) {
+		/* There was some error recorded in the lock file */
+		commit_lock_file(&log_lock);
+	} else {
+		/* No error, clean up any old gc.log */
+		unlink(git_path("gc.log"));
+		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 int gc_config_is_timestamp_never(const char *var)
+{
+	const char *value;
+	timestamp_t expire;
+
+	if (!git_config_get_value(var, &value) && value) {
+		if (parse_expiry_date(value, &expire))
+			die(_("failed to parse '%s' value '%s'"), var, value);
+		return expire == 0;
+	}
+	return 0;
+}
+
+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);
+	}
+
+	if (gc_config_is_timestamp_never("gc.reflogexpire") &&
+	    gc_config_is_timestamp_never("gc.reflogexpireunreachable"))
+		prune_reflogs = 0;
+
+	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.writecommitgraph", &gc_write_commit_graph);
+	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_get_expiry("gc.logexpiry", &gc_log_expire);
+
+	git_config_get_ulong("gc.bigpackthreshold", &big_pack_threshold);
+	git_config_get_ulong("pack.deltacachesize", &max_delta_cache_size);
+
+	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.
+	 */
+	DIR *dir;
+	struct dirent *ent;
+	int auto_threshold;
+	int num_loose = 0;
+	int needed = 0;
+	const unsigned hexsz_loose = the_hash_algo->hexsz - 2;
+
+	dir = opendir(git_path("objects/17"));
+	if (!dir)
+		return 0;
+
+	auto_threshold = DIV_ROUND_UP(gc_auto_threshold, 256);
+	while ((ent = readdir(dir)) != NULL) {
+		if (strspn(ent->d_name, "0123456789abcdef") != hexsz_loose ||
+		    ent->d_name[hexsz_loose] != '\0')
+			continue;
+		if (++num_loose > auto_threshold) {
+			needed = 1;
+			break;
+		}
+	}
+	closedir(dir);
+	return needed;
+}
+
+static struct packed_git *find_base_packs(struct string_list *packs,
+					  unsigned long limit)
+{
+	struct packed_git *p, *base = NULL;
+
+	for (p = get_all_packs(the_repository); p; p = p->next) {
+		if (!p->pack_local)
+			continue;
+		if (limit) {
+			if (p->pack_size >= limit)
+				string_list_append(packs, p->pack_name);
+		} else if (!base || base->pack_size < p->pack_size) {
+			base = p;
+		}
+	}
+
+	if (base)
+		string_list_append(packs, base->pack_name);
+
+	return base;
+}
+
+static int too_many_packs(void)
+{
+	struct packed_git *p;
+	int cnt;
+
+	if (gc_auto_pack_limit <= 0)
+		return 0;
+
+	for (cnt = 0, p = get_all_packs(the_repository); 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 uint64_t total_ram(void)
+{
+#if defined(HAVE_SYSINFO)
+	struct sysinfo si;
+
+	if (!sysinfo(&si))
+		return si.totalram;
+#elif defined(HAVE_BSD_SYSCTL) && (defined(HW_MEMSIZE) || defined(HW_PHYSMEM))
+	int64_t physical_memory;
+	int mib[2];
+	size_t length;
+
+	mib[0] = CTL_HW;
+# if defined(HW_MEMSIZE)
+	mib[1] = HW_MEMSIZE;
+# else
+	mib[1] = HW_PHYSMEM;
+# endif
+	length = sizeof(int64_t);
+	if (!sysctl(mib, 2, &physical_memory, &length, NULL, 0))
+		return physical_memory;
+#elif defined(GIT_WINDOWS_NATIVE)
+	MEMORYSTATUSEX memInfo;
+
+	memInfo.dwLength = sizeof(MEMORYSTATUSEX);
+	if (GlobalMemoryStatusEx(&memInfo))
+		return memInfo.ullTotalPhys;
+#endif
+	return 0;
+}
+
+static uint64_t estimate_repack_memory(struct packed_git *pack)
+{
+	unsigned long nr_objects = approximate_object_count();
+	size_t os_cache, heap;
+
+	if (!pack || !nr_objects)
+		return 0;
+
+	/*
+	 * First we have to scan through at least one pack.
+	 * Assume enough room in OS file cache to keep the entire pack
+	 * or we may accidentally evict data of other processes from
+	 * the cache.
+	 */
+	os_cache = pack->pack_size + pack->index_size;
+	/* then pack-objects needs lots more for book keeping */
+	heap = sizeof(struct object_entry) * nr_objects;
+	/*
+	 * internal rev-list --all --objects takes up some memory too,
+	 * let's say half of it is for blobs
+	 */
+	heap += sizeof(struct blob) * nr_objects / 2;
+	/*
+	 * and the other half is for trees (commits and tags are
+	 * usually insignificant)
+	 */
+	heap += sizeof(struct tree) * nr_objects / 2;
+	/* and then obj_hash[], underestimated in fact */
+	heap += sizeof(struct object *) * nr_objects;
+	/* revindex is used also */
+	heap += sizeof(struct revindex_entry) * nr_objects;
+	/*
+	 * read_sha1_file() (either at delta calculation phase, or
+	 * writing phase) also fills up the delta base cache
+	 */
+	heap += delta_base_cache_limit;
+	/* and of course pack-objects has its own delta cache */
+	heap += max_delta_cache_size;
+
+	return os_cache + heap;
+}
+
+static int keep_one_pack(struct string_list_item *item, void *data)
+{
+	argv_array_pushf(&repack, "--keep-pack=%s", basename(item->string));
+	return 0;
+}
+
+static void add_repack_all_option(struct string_list *keep_pack)
+{
+	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);
+	}
+
+	if (keep_pack)
+		for_each_string_list(keep_pack, keep_one_pack, NULL);
+}
+
+static void add_repack_incremental_option(void)
+{
+	argv_array_push(&repack, "--no-write-bitmap-index");
+}
+
+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()) {
+		struct string_list keep_pack = STRING_LIST_INIT_NODUP;
+
+		if (big_pack_threshold) {
+			find_base_packs(&keep_pack, big_pack_threshold);
+			if (keep_pack.nr >= gc_auto_pack_limit) {
+				big_pack_threshold = 0;
+				string_list_clear(&keep_pack, 0);
+				find_base_packs(&keep_pack, 0);
+			}
+		} else {
+			struct packed_git *p = find_base_packs(&keep_pack, 0);
+			uint64_t mem_have, mem_want;
+
+			mem_have = total_ram();
+			mem_want = estimate_repack_memory(p);
+
+			/*
+			 * Only allow 1/2 of memory for pack-objects, leave
+			 * the rest for the OS and other processes in the
+			 * system.
+			 */
+			if (!mem_have || mem_want < mem_have / 2)
+				string_list_clear(&keep_pack, 0);
+		}
+
+		add_repack_all_option(&keep_pack);
+		string_list_clear(&keep_pack, 0);
+	} else if (too_many_loose_objects())
+		add_repack_incremental_option();
+	else
+		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)
+{
+	struct lock_file lock = LOCK_INIT;
+	char my_host[HOST_NAME_MAX + 1];
+	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 (xgethostname(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[HOST_NAME_MAX + 1];
+		static char *scan_fmt;
+		int should_exit;
+
+		if (!scan_fmt)
+			scan_fmt = xstrfmt("%s %%%ds", "%"SCNuMAX, HOST_NAME_MAX);
+		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, scan_fmt, &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);
+	pidfile = register_tempfile(pidfile_path);
+	free(pidfile_path);
+	return NULL;
+}
+
+/*
+ * Returns 0 if there was no previous error and gc can proceed, 1 if
+ * gc should not proceed due to an error in the last run. Prints a
+ * message and returns -1 if an error occured while reading gc.log
+ */
+static int report_last_gc_error(void)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int ret = 0;
+	ssize_t len;
+	struct stat st;
+	char *gc_log_path = git_pathdup("gc.log");
+
+	if (stat(gc_log_path, &st)) {
+		if (errno == ENOENT)
+			goto done;
+
+		ret = error_errno(_("cannot stat '%s'"), gc_log_path);
+		goto done;
+	}
+
+	if (st.st_mtime < gc_log_expire_time)
+		goto done;
+
+	len = strbuf_read_file(&sb, gc_log_path, 0);
+	if (len < 0)
+		ret = error_errno(_("cannot read '%s'"), gc_log_path);
+	else if (len > 0) {
+		/*
+		 * A previous gc failed.  Report the error, and don't
+		 * bother with an automatic gc run since it is likely
+		 * to fail in the same way.
+		 */
+		warning(_("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"),
+			    gc_log_path, sb.buf);
+		ret = 1;
+	}
+	strbuf_release(&sb);
+done:
+	free(gc_log_path);
+	return ret;
+}
+
+static void gc_before_repack(void)
+{
+	/*
+	 * We may be called twice, as both the pre- and
+	 * post-daemonized phases will call us, but running these
+	 * commands more than once is pointless and wasteful.
+	 */
+	static int done = 0;
+	if (done++)
+		return;
+
+	if (pack_refs && run_command_v_opt(pack_refs_cmd.argv, RUN_GIT_CMD))
+		die(FAILED_RUN, pack_refs_cmd.argv[0]);
+
+	if (prune_reflogs && run_command_v_opt(reflog.argv, RUN_GIT_CMD))
+		die(FAILED_RUN, reflog.argv[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;
+	int keep_base_pack = -1;
+	timestamp_t dummy;
+
+	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_F(0, "auto", &auto_gc, N_("enable auto-gc mode"),
+			   PARSE_OPT_NOCOMPLETE),
+		OPT_BOOL_F(0, "force", &force,
+			   N_("force running gc even if there may be another gc running"),
+			   PARSE_OPT_NOCOMPLETE),
+		OPT_BOOL(0, "keep-largest-pack", &keep_base_pack,
+			 N_("repack all other packs except the largest pack")),
+		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);
+
+	/* default expiry time, overwritten in gc_config */
+	gc_config();
+	if (parse_expiry_date(gc_log_expire, &gc_log_expire_time))
+		die(_("failed to parse gc.logexpiry value %s"), gc_log_expire);
+
+	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 (prune_expire && parse_expiry_date(prune_expire, &dummy))
+		die(_("failed to parse prune expiry value %s"), prune_expire);
+
+	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) {
+			int ret = report_last_gc_error();
+			if (ret < 0)
+				/* an I/O error occured, already reported */
+				exit(128);
+			if (ret == 1)
+				/* Last gc --auto failed. Skip this one. */
+				return 0;
+
+			if (lock_repo_for_gc(force, &pid))
+				return 0;
+			gc_before_repack(); /* dies on failure */
+			delete_tempfile(&pidfile);
+
+			/*
+			 * failure to daemonize is ok, we'll continue
+			 * in foreground
+			 */
+			daemonized = !daemonize();
+		}
+	} else {
+		struct string_list keep_pack = STRING_LIST_INIT_NODUP;
+
+		if (keep_base_pack != -1) {
+			if (keep_base_pack)
+				find_base_packs(&keep_pack, 0);
+		} else if (big_pack_threshold) {
+			find_base_packs(&keep_pack, big_pack_threshold);
+		}
+
+		add_repack_all_option(&keep_pack);
+		string_list_clear(&keep_pack, 0);
+	}
+
+	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);
+	}
+
+	gc_before_repack();
+
+	if (!repository_format_precious_objects) {
+		close_object_store(the_repository->objects);
+		if (run_command_v_opt(repack.argv, RUN_GIT_CMD))
+			die(FAILED_RUN, repack.argv[0]);
+
+		if (prune_expire) {
+			argv_array_push(&prune, prune_expire);
+			if (quiet)
+				argv_array_push(&prune, "--no-progress");
+			if (repository_format_partial_clone)
+				argv_array_push(&prune,
+						"--exclude-promisor-objects");
+			if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
+				die(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))
+			die(FAILED_RUN, prune_worktrees.argv[0]);
+	}
+
+	if (run_command_v_opt(rerere.argv, RUN_GIT_CMD))
+		die(FAILED_RUN, rerere.argv[0]);
+
+	report_garbage = report_pack_garbage;
+	reprepare_packed_git(the_repository);
+	if (pack_garbage.nr > 0) {
+		close_object_store(the_repository->objects);
+		clean_pack_garbage();
+	}
+
+	if (gc_write_commit_graph &&
+	    write_commit_graph_reachable(get_object_directory(),
+					 !quiet && !daemonized ? COMMIT_GRAPH_PROGRESS : 0,
+					 NULL))
+		return 1;
+
+	if (auto_gc && too_many_loose_objects())
+		warning(_("There are too many unreachable loose objects; "
+			"run 'git prune' to remove them."));
+
+	if (!daemonized)
+		unlink(git_path("gc.log"));
+
+	return 0;
+}