1 files changed, 580 insertions, 0 deletions

diff --git a/third_party/git/builtin/repack.c b/third_party/git/builtin/repack.c
new file mode 100644
index 000000000000..0781763b06e8
--- /dev/null
+++ b/third_party/git/builtin/repack.c
@@ -0,0 +1,580 @@
+#include "builtin.h"
+#include "cache.h"
+#include "config.h"
+#include "dir.h"
+#include "parse-options.h"
+#include "run-command.h"
+#include "sigchain.h"
+#include "strbuf.h"
+#include "string-list.h"
+#include "argv-array.h"
+#include "midx.h"
+#include "packfile.h"
+#include "object-store.h"
+#include "promisor-remote.h"
+
+static int delta_base_offset = 1;
+static int pack_kept_objects = -1;
+static int write_bitmaps = -1;
+static int use_delta_islands;
+static char *packdir, *packtmp;
+
+static const char *const git_repack_usage[] = {
+	N_("git repack [<options>]"),
+	NULL
+};
+
+static const char incremental_bitmap_conflict_error[] = N_(
+"Incremental repacks are incompatible with bitmap indexes.  Use\n"
+"--no-write-bitmap-index or disable the pack.writebitmaps configuration."
+);
+
+
+static int repack_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "repack.usedeltabaseoffset")) {
+		delta_base_offset = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "repack.packkeptobjects")) {
+		pack_kept_objects = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "repack.writebitmaps") ||
+	    !strcmp(var, "pack.writebitmaps")) {
+		write_bitmaps = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "repack.usedeltaislands")) {
+		use_delta_islands = git_config_bool(var, value);
+		return 0;
+	}
+	return git_default_config(var, value, cb);
+}
+
+/*
+ * Remove temporary $GIT_OBJECT_DIRECTORY/pack/.tmp-$$-pack-* files.
+ */
+static void remove_temporary_files(void)
+{
+	struct strbuf buf = STRBUF_INIT;
+	size_t dirlen, prefixlen;
+	DIR *dir;
+	struct dirent *e;
+
+	dir = opendir(packdir);
+	if (!dir)
+		return;
+
+	/* Point at the slash at the end of ".../objects/pack/" */
+	dirlen = strlen(packdir) + 1;
+	strbuf_addstr(&buf, packtmp);
+	/* Hold the length of  ".tmp-%d-pack-" */
+	prefixlen = buf.len - dirlen;
+
+	while ((e = readdir(dir))) {
+		if (strncmp(e->d_name, buf.buf + dirlen, prefixlen))
+			continue;
+		strbuf_setlen(&buf, dirlen);
+		strbuf_addstr(&buf, e->d_name);
+		unlink(buf.buf);
+	}
+	closedir(dir);
+	strbuf_release(&buf);
+}
+
+static void remove_pack_on_signal(int signo)
+{
+	remove_temporary_files();
+	sigchain_pop(signo);
+	raise(signo);
+}
+
+/*
+ * Adds all packs hex strings to the fname list, which do not
+ * have a corresponding .keep file. These packs are not to
+ * be kept if we are going to pack everything into one file.
+ */
+static void get_non_kept_pack_filenames(struct string_list *fname_list,
+					const struct string_list *extra_keep)
+{
+	DIR *dir;
+	struct dirent *e;
+	char *fname;
+
+	if (!(dir = opendir(packdir)))
+		return;
+
+	while ((e = readdir(dir)) != NULL) {
+		size_t len;
+		int i;
+
+		for (i = 0; i < extra_keep->nr; i++)
+			if (!fspathcmp(e->d_name, extra_keep->items[i].string))
+				break;
+		if (extra_keep->nr > 0 && i < extra_keep->nr)
+			continue;
+
+		if (!strip_suffix(e->d_name, ".pack", &len))
+			continue;
+
+		fname = xmemdupz(e->d_name, len);
+
+		if (!file_exists(mkpath("%s/%s.keep", packdir, fname)))
+			string_list_append_nodup(fname_list, fname);
+		else
+			free(fname);
+	}
+	closedir(dir);
+}
+
+static void remove_redundant_pack(const char *dir_name, const char *base_name)
+{
+	struct strbuf buf = STRBUF_INIT;
+	strbuf_addf(&buf, "%s/%s.pack", dir_name, base_name);
+	unlink_pack_path(buf.buf, 1);
+	strbuf_release(&buf);
+}
+
+struct pack_objects_args {
+	const char *window;
+	const char *window_memory;
+	const char *depth;
+	const char *threads;
+	const char *max_pack_size;
+	int no_reuse_delta;
+	int no_reuse_object;
+	int quiet;
+	int local;
+};
+
+static void prepare_pack_objects(struct child_process *cmd,
+				 const struct pack_objects_args *args)
+{
+	argv_array_push(&cmd->args, "pack-objects");
+	if (args->window)
+		argv_array_pushf(&cmd->args, "--window=%s", args->window);
+	if (args->window_memory)
+		argv_array_pushf(&cmd->args, "--window-memory=%s", args->window_memory);
+	if (args->depth)
+		argv_array_pushf(&cmd->args, "--depth=%s", args->depth);
+	if (args->threads)
+		argv_array_pushf(&cmd->args, "--threads=%s", args->threads);
+	if (args->max_pack_size)
+		argv_array_pushf(&cmd->args, "--max-pack-size=%s", args->max_pack_size);
+	if (args->no_reuse_delta)
+		argv_array_pushf(&cmd->args, "--no-reuse-delta");
+	if (args->no_reuse_object)
+		argv_array_pushf(&cmd->args, "--no-reuse-object");
+	if (args->local)
+		argv_array_push(&cmd->args,  "--local");
+	if (args->quiet)
+		argv_array_push(&cmd->args,  "--quiet");
+	if (delta_base_offset)
+		argv_array_push(&cmd->args,  "--delta-base-offset");
+	argv_array_push(&cmd->args, packtmp);
+	cmd->git_cmd = 1;
+	cmd->out = -1;
+}
+
+/*
+ * Write oid to the given struct child_process's stdin, starting it first if
+ * necessary.
+ */
+static int write_oid(const struct object_id *oid, struct packed_git *pack,
+		     uint32_t pos, void *data)
+{
+	struct child_process *cmd = data;
+
+	if (cmd->in == -1) {
+		if (start_command(cmd))
+			die(_("could not start pack-objects to repack promisor objects"));
+	}
+
+	xwrite(cmd->in, oid_to_hex(oid), the_hash_algo->hexsz);
+	xwrite(cmd->in, "\n", 1);
+	return 0;
+}
+
+static void repack_promisor_objects(const struct pack_objects_args *args,
+				    struct string_list *names)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	FILE *out;
+	struct strbuf line = STRBUF_INIT;
+
+	prepare_pack_objects(&cmd, args);
+	cmd.in = -1;
+
+	/*
+	 * NEEDSWORK: Giving pack-objects only the OIDs without any ordering
+	 * hints may result in suboptimal deltas in the resulting pack. See if
+	 * the OIDs can be sent with fake paths such that pack-objects can use a
+	 * {type -> existing pack order} ordering when computing deltas instead
+	 * of a {type -> size} ordering, which may produce better deltas.
+	 */
+	for_each_packed_object(write_oid, &cmd,
+			       FOR_EACH_OBJECT_PROMISOR_ONLY);
+
+	if (cmd.in == -1)
+		/* No packed objects; cmd was never started */
+		return;
+
+	close(cmd.in);
+
+	out = xfdopen(cmd.out, "r");
+	while (strbuf_getline_lf(&line, out) != EOF) {
+		char *promisor_name;
+		int fd;
+		if (line.len != the_hash_algo->hexsz)
+			die(_("repack: Expecting full hex object ID lines only from pack-objects."));
+		string_list_append(names, line.buf);
+
+		/*
+		 * pack-objects creates the .pack and .idx files, but not the
+		 * .promisor file. Create the .promisor file, which is empty.
+		 *
+		 * NEEDSWORK: fetch-pack sometimes generates non-empty
+		 * .promisor files containing the ref names and associated
+		 * hashes at the point of generation of the corresponding
+		 * packfile, but this would not preserve their contents. Maybe
+		 * concatenate the contents of all .promisor files instead of
+		 * just creating a new empty file.
+		 */
+		promisor_name = mkpathdup("%s-%s.promisor", packtmp,
+					  line.buf);
+		fd = open(promisor_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
+		if (fd < 0)
+			die_errno(_("unable to create '%s'"), promisor_name);
+		close(fd);
+		free(promisor_name);
+	}
+	fclose(out);
+	if (finish_command(&cmd))
+		die(_("could not finish pack-objects to repack promisor objects"));
+}
+
+#define ALL_INTO_ONE 1
+#define LOOSEN_UNREACHABLE 2
+
+int cmd_repack(int argc, const char **argv, const char *prefix)
+{
+	struct {
+		const char *name;
+		unsigned optional:1;
+	} exts[] = {
+		{".pack"},
+		{".idx"},
+		{".bitmap", 1},
+		{".promisor", 1},
+	};
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	struct string_list_item *item;
+	struct string_list names = STRING_LIST_INIT_DUP;
+	struct string_list rollback = STRING_LIST_INIT_NODUP;
+	struct string_list existing_packs = STRING_LIST_INIT_DUP;
+	struct strbuf line = STRBUF_INIT;
+	int i, ext, ret, failed;
+	FILE *out;
+
+	/* variables to be filled by option parsing */
+	int pack_everything = 0;
+	int delete_redundant = 0;
+	const char *unpack_unreachable = NULL;
+	int keep_unreachable = 0;
+	struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
+	int no_update_server_info = 0;
+	int midx_cleared = 0;
+	struct pack_objects_args po_args = {NULL};
+
+	struct option builtin_repack_options[] = {
+		OPT_BIT('a', NULL, &pack_everything,
+				N_("pack everything in a single pack"), ALL_INTO_ONE),
+		OPT_BIT('A', NULL, &pack_everything,
+				N_("same as -a, and turn unreachable objects loose"),
+				   LOOSEN_UNREACHABLE | ALL_INTO_ONE),
+		OPT_BOOL('d', NULL, &delete_redundant,
+				N_("remove redundant packs, and run git-prune-packed")),
+		OPT_BOOL('f', NULL, &po_args.no_reuse_delta,
+				N_("pass --no-reuse-delta to git-pack-objects")),
+		OPT_BOOL('F', NULL, &po_args.no_reuse_object,
+				N_("pass --no-reuse-object to git-pack-objects")),
+		OPT_BOOL('n', NULL, &no_update_server_info,
+				N_("do not run git-update-server-info")),
+		OPT__QUIET(&po_args.quiet, N_("be quiet")),
+		OPT_BOOL('l', "local", &po_args.local,
+				N_("pass --local to git-pack-objects")),
+		OPT_BOOL('b', "write-bitmap-index", &write_bitmaps,
+				N_("write bitmap index")),
+		OPT_BOOL('i', "delta-islands", &use_delta_islands,
+				N_("pass --delta-islands to git-pack-objects")),
+		OPT_STRING(0, "unpack-unreachable", &unpack_unreachable, N_("approxidate"),
+				N_("with -A, do not loosen objects older than this")),
+		OPT_BOOL('k', "keep-unreachable", &keep_unreachable,
+				N_("with -a, repack unreachable objects")),
+		OPT_STRING(0, "window", &po_args.window, N_("n"),
+				N_("size of the window used for delta compression")),
+		OPT_STRING(0, "window-memory", &po_args.window_memory, N_("bytes"),
+				N_("same as the above, but limit memory size instead of entries count")),
+		OPT_STRING(0, "depth", &po_args.depth, N_("n"),
+				N_("limits the maximum delta depth")),
+		OPT_STRING(0, "threads", &po_args.threads, N_("n"),
+				N_("limits the maximum number of threads")),
+		OPT_STRING(0, "max-pack-size", &po_args.max_pack_size, N_("bytes"),
+				N_("maximum size of each packfile")),
+		OPT_BOOL(0, "pack-kept-objects", &pack_kept_objects,
+				N_("repack objects in packs marked with .keep")),
+		OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
+				N_("do not repack this pack")),
+		OPT_END()
+	};
+
+	git_config(repack_config, NULL);
+
+	argc = parse_options(argc, argv, prefix, builtin_repack_options,
+				git_repack_usage, 0);
+
+	if (delete_redundant && repository_format_precious_objects)
+		die(_("cannot delete packs in a precious-objects repo"));
+
+	if (keep_unreachable &&
+	    (unpack_unreachable || (pack_everything & LOOSEN_UNREACHABLE)))
+		die(_("--keep-unreachable and -A are incompatible"));
+
+	if (write_bitmaps < 0) {
+		if (!(pack_everything & ALL_INTO_ONE) ||
+		    !is_bare_repository())
+			write_bitmaps = 0;
+	}
+	if (pack_kept_objects < 0)
+		pack_kept_objects = write_bitmaps > 0;
+
+	if (write_bitmaps && !(pack_everything & ALL_INTO_ONE))
+		die(_(incremental_bitmap_conflict_error));
+
+	packdir = mkpathdup("%s/pack", get_object_directory());
+	packtmp = mkpathdup("%s/.tmp-%d-pack", packdir, (int)getpid());
+
+	sigchain_push_common(remove_pack_on_signal);
+
+	prepare_pack_objects(&cmd, &po_args);
+
+	argv_array_push(&cmd.args, "--keep-true-parents");
+	if (!pack_kept_objects)
+		argv_array_push(&cmd.args, "--honor-pack-keep");
+	for (i = 0; i < keep_pack_list.nr; i++)
+		argv_array_pushf(&cmd.args, "--keep-pack=%s",
+				 keep_pack_list.items[i].string);
+	argv_array_push(&cmd.args, "--non-empty");
+	argv_array_push(&cmd.args, "--all");
+	argv_array_push(&cmd.args, "--reflog");
+	argv_array_push(&cmd.args, "--indexed-objects");
+	if (has_promisor_remote())
+		argv_array_push(&cmd.args, "--exclude-promisor-objects");
+	if (write_bitmaps > 0)
+		argv_array_push(&cmd.args, "--write-bitmap-index");
+	else if (write_bitmaps < 0)
+		argv_array_push(&cmd.args, "--write-bitmap-index-quiet");
+	if (use_delta_islands)
+		argv_array_push(&cmd.args, "--delta-islands");
+
+	if (pack_everything & ALL_INTO_ONE) {
+		get_non_kept_pack_filenames(&existing_packs, &keep_pack_list);
+
+		repack_promisor_objects(&po_args, &names);
+
+		if (existing_packs.nr && delete_redundant) {
+			if (unpack_unreachable) {
+				argv_array_pushf(&cmd.args,
+						"--unpack-unreachable=%s",
+						unpack_unreachable);
+				argv_array_push(&cmd.env_array, "GIT_REF_PARANOIA=1");
+			} else if (pack_everything & LOOSEN_UNREACHABLE) {
+				argv_array_push(&cmd.args,
+						"--unpack-unreachable");
+			} else if (keep_unreachable) {
+				argv_array_push(&cmd.args, "--keep-unreachable");
+				argv_array_push(&cmd.args, "--pack-loose-unreachable");
+			} else {
+				argv_array_push(&cmd.env_array, "GIT_REF_PARANOIA=1");
+			}
+		}
+	} else {
+		argv_array_push(&cmd.args, "--unpacked");
+		argv_array_push(&cmd.args, "--incremental");
+	}
+
+	cmd.no_stdin = 1;
+
+	ret = start_command(&cmd);
+	if (ret)
+		return ret;
+
+	out = xfdopen(cmd.out, "r");
+	while (strbuf_getline_lf(&line, out) != EOF) {
+		if (line.len != the_hash_algo->hexsz)
+			die(_("repack: Expecting full hex object ID lines only from pack-objects."));
+		string_list_append(&names, line.buf);
+	}
+	fclose(out);
+	ret = finish_command(&cmd);
+	if (ret)
+		return ret;
+
+	if (!names.nr && !po_args.quiet)
+		printf_ln(_("Nothing new to pack."));
+
+	close_object_store(the_repository->objects);
+
+	/*
+	 * Ok we have prepared all new packfiles.
+	 * First see if there are packs of the same name and if so
+	 * if we can move them out of the way (this can happen if we
+	 * repacked immediately after packing fully.
+	 */
+	failed = 0;
+	for_each_string_list_item(item, &names) {
+		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
+			char *fname, *fname_old;
+
+			if (!midx_cleared) {
+				clear_midx_file(the_repository);
+				midx_cleared = 1;
+			}
+
+			fname = mkpathdup("%s/pack-%s%s", packdir,
+						item->string, exts[ext].name);
+			if (!file_exists(fname)) {
+				free(fname);
+				continue;
+			}
+
+			fname_old = mkpathdup("%s/old-%s%s", packdir,
+						item->string, exts[ext].name);
+			if (file_exists(fname_old))
+				if (unlink(fname_old))
+					failed = 1;
+
+			if (!failed && rename(fname, fname_old)) {
+				free(fname);
+				free(fname_old);
+				failed = 1;
+				break;
+			} else {
+				string_list_append(&rollback, fname);
+				free(fname_old);
+			}
+		}
+		if (failed)
+			break;
+	}
+	if (failed) {
+		struct string_list rollback_failure = STRING_LIST_INIT_DUP;
+		for_each_string_list_item(item, &rollback) {
+			char *fname, *fname_old;
+			fname = mkpathdup("%s/%s", packdir, item->string);
+			fname_old = mkpathdup("%s/old-%s", packdir, item->string);
+			if (rename(fname_old, fname))
+				string_list_append(&rollback_failure, fname);
+			free(fname);
+			free(fname_old);
+		}
+
+		if (rollback_failure.nr) {
+			int i;
+			fprintf(stderr,
+				_("WARNING: Some packs in use have been renamed by\n"
+				  "WARNING: prefixing old- to their name, in order to\n"
+				  "WARNING: replace them with the new version of the\n"
+				  "WARNING: file.  But the operation failed, and the\n"
+				  "WARNING: attempt to rename them back to their\n"
+				  "WARNING: original names also failed.\n"
+				  "WARNING: Please rename them in %s manually:\n"), packdir);
+			for (i = 0; i < rollback_failure.nr; i++)
+				fprintf(stderr, "WARNING:   old-%s -> %s\n",
+					rollback_failure.items[i].string,
+					rollback_failure.items[i].string);
+		}
+		exit(1);
+	}
+
+	/* Now the ones with the same name are out of the way... */
+	for_each_string_list_item(item, &names) {
+		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
+			char *fname, *fname_old;
+			struct stat statbuffer;
+			int exists = 0;
+			fname = mkpathdup("%s/pack-%s%s",
+					packdir, item->string, exts[ext].name);
+			fname_old = mkpathdup("%s-%s%s",
+					packtmp, item->string, exts[ext].name);
+			if (!stat(fname_old, &statbuffer)) {
+				statbuffer.st_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
+				chmod(fname_old, statbuffer.st_mode);
+				exists = 1;
+			}
+			if (exists || !exts[ext].optional) {
+				if (rename(fname_old, fname))
+					die_errno(_("renaming '%s' failed"), fname_old);
+			}
+			free(fname);
+			free(fname_old);
+		}
+	}
+
+	/* Remove the "old-" files */
+	for_each_string_list_item(item, &names) {
+		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
+			char *fname;
+			fname = mkpathdup("%s/old-%s%s",
+					  packdir,
+					  item->string,
+					  exts[ext].name);
+			if (remove_path(fname))
+				warning(_("failed to remove '%s'"), fname);
+			free(fname);
+		}
+	}
+
+	/* End of pack replacement. */
+
+	reprepare_packed_git(the_repository);
+
+	if (delete_redundant) {
+		const int hexsz = the_hash_algo->hexsz;
+		int opts = 0;
+		string_list_sort(&names);
+		for_each_string_list_item(item, &existing_packs) {
+			char *sha1;
+			size_t len = strlen(item->string);
+			if (len < hexsz)
+				continue;
+			sha1 = item->string + len - hexsz;
+			if (!string_list_has_string(&names, sha1))
+				remove_redundant_pack(packdir, item->string);
+		}
+		if (!po_args.quiet && isatty(2))
+			opts |= PRUNE_PACKED_VERBOSE;
+		prune_packed_objects(opts);
+
+		if (!keep_unreachable &&
+		    (!(pack_everything & LOOSEN_UNREACHABLE) ||
+		     unpack_unreachable) &&
+		    is_repository_shallow(the_repository))
+			prune_shallow(PRUNE_QUICK);
+	}
+
+	if (!no_update_server_info)
+		update_server_info(0);
+	remove_temporary_files();
+
+	if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0))
+		write_midx_file(get_object_directory(), 0);
+
+	string_list_clear(&names, 0);
+	string_list_clear(&rollback, 0);
+	string_list_clear(&existing_packs, 0);
+	strbuf_release(&line);
+
+	return 0;
+}