[thirdparty/git.git] / builtin / unpack-objects.c

#define USE_THE_REPOSITORY_VARIABLE
#define DISABLE_SIGN_COMPARE_WARNINGS

#include "builtin.h"
#include "bulk-checkin.h"
#include "config.h"
#include "environment.h"
#include "gettext.h"
#include "git-zlib.h"
#include "hex.h"
#include "object-file.h"
#include "object-store.h"
#include "object.h"
#include "delta.h"
#include "pack.h"
#include "blob.h"
#include "replace-object.h"
#include "strbuf.h"
#include "progress.h"
#include "decorate.h"
#include "fsck.h"
#include "packfile.h"

static int dry_run, quiet, recover, has_errors, strict;
static const char unpack_usage[] = "git unpack-objects [-n] [-q] [-r] [--strict]";

/* We always read in 4kB chunks. */
static unsigned char buffer[4096];
static unsigned int offset, len;
static off_t consumed_bytes;
static off_t max_input_size;
static struct git_hash_ctx ctx;
static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
static struct progress *progress;

/*
 * When running under --strict mode, objects whose reachability are
 * suspect are kept in core without getting written in the object
 * store.
 */
struct obj_buffer {
	char *buffer;
	unsigned long size;
};

static struct decoration obj_decorate;

static struct obj_buffer *lookup_object_buffer(struct object *base)
{
	return lookup_decoration(&obj_decorate, base);
}

static void add_object_buffer(struct object *object, char *buffer, unsigned long size)
{
	struct obj_buffer *obj;
	CALLOC_ARRAY(obj, 1);
	obj->buffer = buffer;
	obj->size = size;
	if (add_decoration(&obj_decorate, object, obj))
		die("object %s tried to add buffer twice!", oid_to_hex(&object->oid));
}

/*
 * Make sure at least "min" bytes are available in the buffer, and
 * return the pointer to the buffer.
 */
static void *fill(int min)
{
	if (min <= len)
		return buffer + offset;
	if (min > sizeof(buffer))
		die("cannot fill %d bytes", min);
	if (offset) {
		git_hash_update(&ctx, buffer, offset);
		memmove(buffer, buffer + offset, len);
		offset = 0;
	}
	do {
		ssize_t ret = xread(0, buffer + len, sizeof(buffer) - len);
		if (ret <= 0) {
			if (!ret)
				die("early EOF");
			die_errno("read error on input");
		}
		len += ret;
	} while (len < min);
	return buffer;
}

static void use(int bytes)
{
	if (bytes > len)
		die("used more bytes than were available");
	len -= bytes;
	offset += bytes;

	/* make sure off_t is sufficiently large not to wrap */
	if (signed_add_overflows(consumed_bytes, bytes))
		die("pack too large for current definition of off_t");
	consumed_bytes += bytes;
	if (max_input_size && consumed_bytes > max_input_size)
		die(_("pack exceeds maximum allowed size"));
	display_throughput(progress, consumed_bytes);
}

/*
 * Decompress zstream from the standard input into a newly
 * allocated buffer of specified size and return the buffer.
 * The caller is responsible to free the returned buffer.
 *
 * But for dry_run mode, "get_data()" is only used to check the
 * integrity of data, and the returned buffer is not used at all.
 * Therefore, in dry_run mode, "get_data()" will release the small
 * allocated buffer which is reused to hold temporary zstream output
 * and return NULL instead of returning garbage data.
 */
static void *get_data(unsigned long size)
{
	git_zstream stream;
	unsigned long bufsize = dry_run && size > 8192 ? 8192 : size;
	void *buf = xmallocz(bufsize);

	memset(&stream, 0, sizeof(stream));

	stream.next_out = buf;
	stream.avail_out = bufsize;
	stream.next_in = fill(1);
	stream.avail_in = len;
	git_inflate_init(&stream);

	for (;;) {
		int ret = git_inflate(&stream, 0);
		use(len - stream.avail_in);
		if (stream.total_out == size && ret == Z_STREAM_END)
			break;
		if (ret != Z_OK) {
			error("inflate returned %d", ret);
			FREE_AND_NULL(buf);
			if (!recover)
				exit(1);
			has_errors = 1;
			break;
		}
		stream.next_in = fill(1);
		stream.avail_in = len;
		if (dry_run) {
			/* reuse the buffer in dry_run mode */
			stream.next_out = buf;
			stream.avail_out = bufsize > size - stream.total_out ?
						   size - stream.total_out :
						   bufsize;
		}
	}
	git_inflate_end(&stream);
	if (dry_run)
		FREE_AND_NULL(buf);
	return buf;
}

struct delta_info {
	struct object_id base_oid;
	unsigned nr;
	off_t base_offset;
	unsigned long size;
	void *delta;
	struct delta_info *next;
};

static struct delta_info *delta_list;

static void add_delta_to_list(unsigned nr, const struct object_id *base_oid,
			      off_t base_offset,
			      void *delta, unsigned long size)
{
	struct delta_info *info = xmalloc(sizeof(*info));

	oidcpy(&info->base_oid, base_oid);
	info->base_offset = base_offset;
	info->size = size;
	info->delta = delta;
	info->nr = nr;
	info->next = delta_list;
	delta_list = info;
}

struct obj_info {
	off_t offset;
	struct object_id oid;
	struct object *obj;
};

/* Remember to update object flag allocation in object.h */
#define FLAG_OPEN (1u<<20)
#define FLAG_WRITTEN (1u<<21)

static struct obj_info *obj_list;
static unsigned nr_objects;

/*
 * Called only from check_object() after it verified this object
 * is Ok.
 */
static void write_cached_object(struct object *obj, struct obj_buffer *obj_buf)
{
	struct object_id oid;

	if (write_object_file(obj_buf->buffer, obj_buf->size,
			      obj->type, &oid) < 0)
		die("failed to write object %s", oid_to_hex(&obj->oid));
	obj->flags |= FLAG_WRITTEN;
}

/*
 * At the very end of the processing, write_rest() scans the objects
 * that have reachability requirements and calls this function.
 * Verify its reachability and validity recursively and write it out.
 */
static int check_object(struct object *obj, enum object_type type,
			void *data UNUSED,
			struct fsck_options *options UNUSED)
{
	struct obj_buffer *obj_buf;

	if (!obj)
		return 1;

	if (obj->flags & FLAG_WRITTEN)
		return 0;

	if (type != OBJ_ANY && obj->type != type)
		die("object type mismatch");

	if (!(obj->flags & FLAG_OPEN)) {
		unsigned long size;
		int type = oid_object_info(the_repository, &obj->oid, &size);
		if (type != obj->type || type <= 0)
			die("object of unexpected type");
		obj->flags |= FLAG_WRITTEN;
		return 0;
	}

	obj_buf = lookup_object_buffer(obj);
	if (!obj_buf)
		die("Whoops! Cannot find object '%s'", oid_to_hex(&obj->oid));
	if (fsck_object(obj, obj_buf->buffer, obj_buf->size, &fsck_options))
		die("fsck error in packed object");
	fsck_options.walk = check_object;
	if (fsck_walk(obj, NULL, &fsck_options))
		die("Error on reachable objects of %s", oid_to_hex(&obj->oid));
	write_cached_object(obj, obj_buf);
	return 0;
}

static void write_rest(void)
{
	unsigned i;
	for (i = 0; i < nr_objects; i++) {
		if (obj_list[i].obj)
			check_object(obj_list[i].obj, OBJ_ANY, NULL, NULL);
	}
}

static void added_object(unsigned nr, enum object_type type,
			 void *data, unsigned long size);

/*
 * Write out nr-th object from the list, now we know the contents
 * of it.  Under --strict, this buffers structured objects in-core,
 * to be checked at the end.
 */
static void write_object(unsigned nr, enum object_type type,
			 void *buf, unsigned long size)
{
	if (!strict) {
		if (write_object_file(buf, size, type,
				      &obj_list[nr].oid) < 0)
			die("failed to write object");
		added_object(nr, type, buf, size);
		free(buf);
		obj_list[nr].obj = NULL;
	} else if (type == OBJ_BLOB) {
		struct blob *blob;
		if (write_object_file(buf, size, type,
				      &obj_list[nr].oid) < 0)
			die("failed to write object");
		added_object(nr, type, buf, size);
		free(buf);

		blob = lookup_blob(the_repository, &obj_list[nr].oid);
		if (blob)
			blob->object.flags |= FLAG_WRITTEN;
		else
			die("invalid blob object");
		obj_list[nr].obj = NULL;
	} else {
		struct object *obj;
		int eaten;
		hash_object_file(the_hash_algo, buf, size, type,
				 &obj_list[nr].oid);
		added_object(nr, type, buf, size);
		obj = parse_object_buffer(the_repository, &obj_list[nr].oid,
					  type, size, buf,
					  &eaten);
		if (!obj)
			die("invalid %s", type_name(type));
		add_object_buffer(obj, buf, size);
		obj->flags |= FLAG_OPEN;
		obj_list[nr].obj = obj;
	}
}

static void resolve_delta(unsigned nr, enum object_type type,
			  void *base, unsigned long base_size,
			  void *delta, unsigned long delta_size)
{
	void *result;
	unsigned long result_size;

	result = patch_delta(base, base_size,
			     delta, delta_size,
			     &result_size);
	if (!result)
		die("failed to apply delta");
	free(delta);
	write_object(nr, type, result, result_size);
}

/*
 * We now know the contents of an object (which is nr-th in the pack);
 * resolve all the deltified objects that are based on it.
 */
static void added_object(unsigned nr, enum object_type type,
			 void *data, unsigned long size)
{
	struct delta_info **p = &delta_list;
	struct delta_info *info;

	while ((info = *p) != NULL) {
		if (oideq(&info->base_oid, &obj_list[nr].oid) ||
		    info->base_offset == obj_list[nr].offset) {
			*p = info->next;
			p = &delta_list;
			resolve_delta(info->nr, type, data, size,
				      info->delta, info->size);
			free(info);
			continue;
		}
		p = &info->next;
	}
}

static void unpack_non_delta_entry(enum object_type type, unsigned long size,
				   unsigned nr)
{
	void *buf = get_data(size);

	if (buf)
		write_object(nr, type, buf, size);
}

struct input_zstream_data {
	git_zstream *zstream;
	unsigned char buf[8192];
	int status;
};

static const void *feed_input_zstream(struct input_stream *in_stream,
				      unsigned long *readlen)
{
	struct input_zstream_data *data = in_stream->data;
	git_zstream *zstream = data->zstream;
	void *in = fill(1);

	if (in_stream->is_finished) {
		*readlen = 0;
		return NULL;
	}

	zstream->next_out = data->buf;
	zstream->avail_out = sizeof(data->buf);
	zstream->next_in = in;
	zstream->avail_in = len;

	data->status = git_inflate(zstream, 0);

	in_stream->is_finished = data->status != Z_OK;
	use(len - zstream->avail_in);
	*readlen = sizeof(data->buf) - zstream->avail_out;

	return data->buf;
}

static void stream_blob(unsigned long size, unsigned nr)
{
	git_zstream zstream = { 0 };
	struct input_zstream_data data = { 0 };
	struct input_stream in_stream = {
		.read = feed_input_zstream,
		.data = &data,
	};
	struct obj_info *info = &obj_list[nr];

	data.zstream = &zstream;
	git_inflate_init(&zstream);

	if (stream_loose_object(&in_stream, size, &info->oid))
		die(_("failed to write object in stream"));

	if (data.status != Z_STREAM_END)
		die(_("inflate returned (%d)"), data.status);
	git_inflate_end(&zstream);

	if (strict) {
		struct blob *blob = lookup_blob(the_repository, &info->oid);

		if (!blob)
			die(_("invalid blob object from stream"));
		blob->object.flags |= FLAG_WRITTEN;
	}
	info->obj = NULL;
}

static int resolve_against_held(unsigned nr, const struct object_id *base,
				void *delta_data, unsigned long delta_size)
{
	struct object *obj;
	struct obj_buffer *obj_buffer;
	obj = lookup_object(the_repository, base);
	if (!obj)
		return 0;
	obj_buffer = lookup_object_buffer(obj);
	if (!obj_buffer)
		return 0;
	resolve_delta(nr, obj->type, obj_buffer->buffer,
		      obj_buffer->size, delta_data, delta_size);
	return 1;
}

static void unpack_delta_entry(enum object_type type, unsigned long delta_size,
			       unsigned nr)
{
	void *delta_data, *base;
	unsigned long base_size;
	struct object_id base_oid;

	if (type == OBJ_REF_DELTA) {
		oidread(&base_oid, fill(the_hash_algo->rawsz), the_repository->hash_algo);
		use(the_hash_algo->rawsz);
		delta_data = get_data(delta_size);
		if (!delta_data)
			return;
		if (has_object(the_repository, &base_oid,
			       HAS_OBJECT_RECHECK_PACKED | HAS_OBJECT_FETCH_PROMISOR))
			; /* Ok we have this one */
		else if (resolve_against_held(nr, &base_oid,
					      delta_data, delta_size))
			return; /* we are done */
		else {
			/* cannot resolve yet --- queue it */
			oidclr(&obj_list[nr].oid, the_repository->hash_algo);
			add_delta_to_list(nr, &base_oid, 0, delta_data, delta_size);
			return;
		}
	} else {
		unsigned base_found = 0;
		unsigned char *pack, c;
		off_t base_offset;
		unsigned lo, mid, hi;

		pack = fill(1);
		c = *pack;
		use(1);
		base_offset = c & 127;
		while (c & 128) {
			base_offset += 1;
			if (!base_offset || MSB(base_offset, 7))
				die("offset value overflow for delta base object");
			pack = fill(1);
			c = *pack;
			use(1);
			base_offset = (base_offset << 7) + (c & 127);
		}
		base_offset = obj_list[nr].offset - base_offset;
		if (base_offset <= 0 || base_offset >= obj_list[nr].offset)
			die("offset value out of bound for delta base object");

		delta_data = get_data(delta_size);
		if (!delta_data)
			return;
		lo = 0;
		hi = nr;
		while (lo < hi) {
			mid = lo + (hi - lo) / 2;
			if (base_offset < obj_list[mid].offset) {
				hi = mid;
			} else if (base_offset > obj_list[mid].offset) {
				lo = mid + 1;
			} else {
				oidcpy(&base_oid, &obj_list[mid].oid);
				base_found = !is_null_oid(&base_oid);
				break;
			}
		}
		if (!base_found) {
			/*
			 * The delta base object is itself a delta that
			 * has not been resolved yet.
			 */
			oidclr(&obj_list[nr].oid, the_repository->hash_algo);
			add_delta_to_list(nr, null_oid(the_hash_algo), base_offset,
					  delta_data, delta_size);
			return;
		}
	}

	if (resolve_against_held(nr, &base_oid, delta_data, delta_size))
		return;

	base = repo_read_object_file(the_repository, &base_oid, &type,
				     &base_size);
	if (!base) {
		error("failed to read delta-pack base object %s",
		      oid_to_hex(&base_oid));
		if (!recover)
			exit(1);
		has_errors = 1;
		return;
	}
	resolve_delta(nr, type, base, base_size, delta_data, delta_size);
	free(base);
}

static void unpack_one(unsigned nr)
{
	unsigned shift;
	unsigned char *pack;
	unsigned long size, c;
	enum object_type type;

	obj_list[nr].offset = consumed_bytes;

	pack = fill(1);
	c = *pack;
	use(1);
	type = (c >> 4) & 7;
	size = (c & 15);
	shift = 4;
	while (c & 0x80) {
		pack = fill(1);
		c = *pack;
		use(1);
		size += (c & 0x7f) << shift;
		shift += 7;
	}

	switch (type) {
	case OBJ_BLOB:
		if (!dry_run &&
		    size > repo_settings_get_big_file_threshold(the_repository)) {
			stream_blob(size, nr);
			return;
		}
		/* fallthrough */
	case OBJ_COMMIT:
	case OBJ_TREE:
	case OBJ_TAG:
		unpack_non_delta_entry(type, size, nr);
		return;
	case OBJ_REF_DELTA:
	case OBJ_OFS_DELTA:
		unpack_delta_entry(type, size, nr);
		return;
	default:
		error("bad object type %d", type);
		has_errors = 1;
		if (recover)
			return;
		exit(1);
	}
}

static void unpack_all(void)
{
	int i;
	unsigned char *hdr = fill(sizeof(struct pack_header));

	if (get_be32(hdr) != PACK_SIGNATURE)
		die("bad pack file");
	hdr += 4;
	if (!pack_version_ok_native(get_be32(hdr)))
		die("unknown pack file version %"PRIu32,
		    get_be32(hdr));
	hdr += 4;
	nr_objects = get_be32(hdr);
	use(sizeof(struct pack_header));

	if (!quiet)
		progress = start_progress(the_repository,
					  _("Unpacking objects"), nr_objects);
	CALLOC_ARRAY(obj_list, nr_objects);
	begin_odb_transaction();
	for (i = 0; i < nr_objects; i++) {
		unpack_one(i);
		display_progress(progress, i + 1);
	}
	end_odb_transaction();
	stop_progress(&progress);

	if (delta_list)
		die("unresolved deltas left after unpacking");
}

int cmd_unpack_objects(int argc,
		       const char **argv,
		       const char *prefix UNUSED,
		       struct repository *repo UNUSED)
{
	int i;
	struct object_id oid;
	struct git_hash_ctx tmp_ctx;

	disable_replace_refs();

	git_config(git_default_config, NULL);

	quiet = !isatty(2);

	show_usage_if_asked(argc, argv, unpack_usage);

	for (i = 1 ; i < argc; i++) {
		const char *arg = argv[i];

		if (*arg == '-') {
			if (!strcmp(arg, "-n")) {
				dry_run = 1;
				continue;
			}
			if (!strcmp(arg, "-q")) {
				quiet = 1;
				continue;
			}
			if (!strcmp(arg, "-r")) {
				recover = 1;
				continue;
			}
			if (!strcmp(arg, "--strict")) {
				strict = 1;
				continue;
			}
			if (skip_prefix(arg, "--strict=", &arg)) {
				strict = 1;
				fsck_set_msg_types(&fsck_options, arg);
				continue;
			}
			if (skip_prefix(arg, "--pack_header=", &arg)) {
				if (parse_pack_header_option(arg,
							     buffer, &len) < 0)
					die(_("bad --pack_header: %s"), arg);
				continue;
			}
			if (skip_prefix(arg, "--max-input-size=", &arg)) {
				max_input_size = strtoumax(arg, NULL, 10);
				continue;
			}
			usage(unpack_usage);
		}

		/* We don't take any non-flag arguments now.. Maybe some day */
		usage(unpack_usage);
	}
	the_hash_algo->init_fn(&ctx);
	unpack_all();
	git_hash_update(&ctx, buffer, offset);
	the_hash_algo->init_fn(&tmp_ctx);
	git_hash_clone(&tmp_ctx, &ctx);
	git_hash_final_oid(&oid, &tmp_ctx);
	if (strict) {
		write_rest();
		if (fsck_finish(&fsck_options))
			die(_("fsck error in pack objects"));
	}
	if (!hasheq(fill(the_hash_algo->rawsz), oid.hash,
		    the_repository->hash_algo))
		die("final sha1 did not match");
	use(the_hash_algo->rawsz);

	/* Write the last part of the buffer to stdout */
	write_in_full(1, buffer + offset, len);

	/* All done */
	return has_errors;
}
Commit	Line	Data
	1	#define USE_THE_REPOSITORY_VARIABLE
	2	#define DISABLE_SIGN_COMPARE_WARNINGS
	3
	4	#include "builtin.h"
	5	#include "bulk-checkin.h"
	6	#include "config.h"
	7	#include "environment.h"
	8	#include "gettext.h"
	9	#include "git-zlib.h"
	10	#include "hex.h"
	11	#include "object-file.h"
	12	#include "object-store.h"
	13	#include "object.h"
	14	#include "delta.h"
	15	#include "pack.h"
	16	#include "blob.h"
	17	#include "replace-object.h"
	18	#include "strbuf.h"
	19	#include "progress.h"
	20	#include "decorate.h"
	21	#include "fsck.h"
	22	#include "packfile.h"
	23
	24	static int dry_run, quiet, recover, has_errors, strict;
	25	static const char unpack_usage[] = "git unpack-objects [-n] [-q] [-r] [--strict]";
	26
	27	/* We always read in 4kB chunks. */
	28	static unsigned char buffer[4096];
	29	static unsigned int offset, len;
	30	static off_t consumed_bytes;
	31	static off_t max_input_size;
	32	static struct git_hash_ctx ctx;
	33	static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
	34	static struct progress *progress;
	35
	36	/*
	37	* When running under --strict mode, objects whose reachability are
	38	* suspect are kept in core without getting written in the object
	39	* store.
	40	*/
	41	struct obj_buffer {
	42	char *buffer;
	43	unsigned long size;
	44	};
	45
	46	static struct decoration obj_decorate;
	47
	48	static struct obj_buffer lookup_object_buffer(struct object base)
	49	{
	50	return lookup_decoration(&obj_decorate, base);
	51	}
	52
	53	static void add_object_buffer(struct object object, char buffer, unsigned long size)
	54	{
	55	struct obj_buffer *obj;
	56	CALLOC_ARRAY(obj, 1);
	57	obj->buffer = buffer;
	58	obj->size = size;
	59	if (add_decoration(&obj_decorate, object, obj))
	60	die("object %s tried to add buffer twice!", oid_to_hex(&object->oid));
	61	}
	62
	63	/*
	64	* Make sure at least "min" bytes are available in the buffer, and
	65	* return the pointer to the buffer.
	66	*/
	67	static void *fill(int min)
	68	{
	69	if (min <= len)
	70	return buffer + offset;
	71	if (min > sizeof(buffer))
	72	die("cannot fill %d bytes", min);
	73	if (offset) {
	74	git_hash_update(&ctx, buffer, offset);
	75	memmove(buffer, buffer + offset, len);
	76	offset = 0;
	77	}
	78	do {
	79	ssize_t ret = xread(0, buffer + len, sizeof(buffer) - len);
	80	if (ret <= 0) {
	81	if (!ret)
	82	die("early EOF");
	83	die_errno("read error on input");
	84	}
	85	len += ret;
	86	} while (len < min);
	87	return buffer;
	88	}
	89
	90	static void use(int bytes)
	91	{
	92	if (bytes > len)
	93	die("used more bytes than were available");
	94	len -= bytes;
	95	offset += bytes;
	96
	97	/* make sure off_t is sufficiently large not to wrap */
	98	if (signed_add_overflows(consumed_bytes, bytes))
	99	die("pack too large for current definition of off_t");
	100	consumed_bytes += bytes;
	101	if (max_input_size && consumed_bytes > max_input_size)
	102	die(_("pack exceeds maximum allowed size"));
	103	display_throughput(progress, consumed_bytes);
	104	}
	105
	106	/*
	107	* Decompress zstream from the standard input into a newly
	108	* allocated buffer of specified size and return the buffer.
	109	* The caller is responsible to free the returned buffer.
	110	*
	111	* But for dry_run mode, "get_data()" is only used to check the
	112	* integrity of data, and the returned buffer is not used at all.
	113	* Therefore, in dry_run mode, "get_data()" will release the small
	114	* allocated buffer which is reused to hold temporary zstream output
	115	* and return NULL instead of returning garbage data.
	116	*/
	117	static void *get_data(unsigned long size)
	118	{
	119	git_zstream stream;
	120	unsigned long bufsize = dry_run && size > 8192 ? 8192 : size;
	121	void *buf = xmallocz(bufsize);
	122
	123	memset(&stream, 0, sizeof(stream));
	124
	125	stream.next_out = buf;
	126	stream.avail_out = bufsize;
	127	stream.next_in = fill(1);
	128	stream.avail_in = len;
	129	git_inflate_init(&stream);
	130
	131	for (;;) {
	132	int ret = git_inflate(&stream, 0);
	133	use(len - stream.avail_in);
	134	if (stream.total_out == size && ret == Z_STREAM_END)
	135	break;
	136	if (ret != Z_OK) {
	137	error("inflate returned %d", ret);
	138	FREE_AND_NULL(buf);
	139	if (!recover)
	140	exit(1);
	141	has_errors = 1;
	142	break;
	143	}
	144	stream.next_in = fill(1);
	145	stream.avail_in = len;
	146	if (dry_run) {
	147	/* reuse the buffer in dry_run mode */
	148	stream.next_out = buf;
	149	stream.avail_out = bufsize > size - stream.total_out ?
	150	size - stream.total_out :
	151	bufsize;
	152	}
	153	}
	154	git_inflate_end(&stream);
	155	if (dry_run)
	156	FREE_AND_NULL(buf);
	157	return buf;
	158	}
	159
	160	struct delta_info {
	161	struct object_id base_oid;
	162	unsigned nr;
	163	off_t base_offset;
	164	unsigned long size;
	165	void *delta;
	166	struct delta_info *next;
	167	};
	168
	169	static struct delta_info *delta_list;
	170
	171	static void add_delta_to_list(unsigned nr, const struct object_id *base_oid,
	172	off_t base_offset,
	173	void *delta, unsigned long size)
	174	{
	175	struct delta_info info = xmalloc(sizeof(info));
	176
	177	oidcpy(&info->base_oid, base_oid);
	178	info->base_offset = base_offset;
	179	info->size = size;
	180	info->delta = delta;
	181	info->nr = nr;
	182	info->next = delta_list;
	183	delta_list = info;
	184	}
	185
	186	struct obj_info {
	187	off_t offset;
	188	struct object_id oid;
	189	struct object *obj;
	190	};
	191
	192	/* Remember to update object flag allocation in object.h */
	193	#define FLAG_OPEN (1u<<20)
	194	#define FLAG_WRITTEN (1u<<21)
	195
	196	static struct obj_info *obj_list;
	197	static unsigned nr_objects;
	198
	199	/*
	200	* Called only from check_object() after it verified this object
	201	* is Ok.
	202	*/
	203	static void write_cached_object(struct object obj, struct obj_buffer obj_buf)
	204	{
	205	struct object_id oid;
	206
	207	if (write_object_file(obj_buf->buffer, obj_buf->size,
	208	obj->type, &oid) < 0)
	209	die("failed to write object %s", oid_to_hex(&obj->oid));
	210	obj->flags \|= FLAG_WRITTEN;
	211	}
	212
	213	/*
	214	* At the very end of the processing, write_rest() scans the objects
	215	* that have reachability requirements and calls this function.
	216	* Verify its reachability and validity recursively and write it out.
	217	*/
	218	static int check_object(struct object *obj, enum object_type type,
	219	void *data UNUSED,
	220	struct fsck_options *options UNUSED)
	221	{
	222	struct obj_buffer *obj_buf;
	223
	224	if (!obj)
	225	return 1;
	226
	227	if (obj->flags & FLAG_WRITTEN)
	228	return 0;
	229
	230	if (type != OBJ_ANY && obj->type != type)
	231	die("object type mismatch");
	232
	233	if (!(obj->flags & FLAG_OPEN)) {
	234	unsigned long size;
	235	int type = oid_object_info(the_repository, &obj->oid, &size);
	236	if (type != obj->type \|\| type <= 0)
	237	die("object of unexpected type");
	238	obj->flags \|= FLAG_WRITTEN;
	239	return 0;
	240	}
	241
	242	obj_buf = lookup_object_buffer(obj);
	243	if (!obj_buf)
	244	die("Whoops! Cannot find object '%s'", oid_to_hex(&obj->oid));
	245	if (fsck_object(obj, obj_buf->buffer, obj_buf->size, &fsck_options))
	246	die("fsck error in packed object");
	247	fsck_options.walk = check_object;
	248	if (fsck_walk(obj, NULL, &fsck_options))
	249	die("Error on reachable objects of %s", oid_to_hex(&obj->oid));
	250	write_cached_object(obj, obj_buf);
	251	return 0;
	252	}
	253
	254	static void write_rest(void)
	255	{
	256	unsigned i;
	257	for (i = 0; i < nr_objects; i++) {
	258	if (obj_list[i].obj)
	259	check_object(obj_list[i].obj, OBJ_ANY, NULL, NULL);
	260	}
	261	}
	262
	263	static void added_object(unsigned nr, enum object_type type,
	264	void *data, unsigned long size);
	265
	266	/*
	267	* Write out nr-th object from the list, now we know the contents
	268	* of it. Under --strict, this buffers structured objects in-core,
	269	* to be checked at the end.
	270	*/
	271	static void write_object(unsigned nr, enum object_type type,
	272	void *buf, unsigned long size)
	273	{
	274	if (!strict) {
	275	if (write_object_file(buf, size, type,
	276	&obj_list[nr].oid) < 0)
	277	die("failed to write object");
	278	added_object(nr, type, buf, size);
	279	free(buf);
	280	obj_list[nr].obj = NULL;
	281	} else if (type == OBJ_BLOB) {
	282	struct blob *blob;
	283	if (write_object_file(buf, size, type,
	284	&obj_list[nr].oid) < 0)
	285	die("failed to write object");
	286	added_object(nr, type, buf, size);
	287	free(buf);
	288
	289	blob = lookup_blob(the_repository, &obj_list[nr].oid);
	290	if (blob)
	291	blob->object.flags \|= FLAG_WRITTEN;
	292	else
	293	die("invalid blob object");
	294	obj_list[nr].obj = NULL;
	295	} else {
	296	struct object *obj;
	297	int eaten;
	298	hash_object_file(the_hash_algo, buf, size, type,
	299	&obj_list[nr].oid);
	300	added_object(nr, type, buf, size);
	301	obj = parse_object_buffer(the_repository, &obj_list[nr].oid,
	302	type, size, buf,
	303	&eaten);
	304	if (!obj)
	305	die("invalid %s", type_name(type));
	306	add_object_buffer(obj, buf, size);
	307	obj->flags \|= FLAG_OPEN;
	308	obj_list[nr].obj = obj;
	309	}
	310	}
	311
	312	static void resolve_delta(unsigned nr, enum object_type type,
	313	void *base, unsigned long base_size,
	314	void *delta, unsigned long delta_size)
	315	{
	316	void *result;
	317	unsigned long result_size;
	318
	319	result = patch_delta(base, base_size,
	320	delta, delta_size,
	321	&result_size);
	322	if (!result)
	323	die("failed to apply delta");
	324	free(delta);
	325	write_object(nr, type, result, result_size);
	326	}
	327
	328	/*
	329	* We now know the contents of an object (which is nr-th in the pack);
	330	* resolve all the deltified objects that are based on it.
	331	*/
	332	static void added_object(unsigned nr, enum object_type type,
	333	void *data, unsigned long size)
	334	{
	335	struct delta_info **p = &delta_list;
	336	struct delta_info *info;
	337
	338	while ((info = *p) != NULL) {
	339	if (oideq(&info->base_oid, &obj_list[nr].oid) \|\|
	340	info->base_offset == obj_list[nr].offset) {
	341	*p = info->next;
	342	p = &delta_list;
	343	resolve_delta(info->nr, type, data, size,
	344	info->delta, info->size);
	345	free(info);
	346	continue;
	347	}
	348	p = &info->next;
	349	}
	350	}
	351
	352	static void unpack_non_delta_entry(enum object_type type, unsigned long size,
	353	unsigned nr)
	354	{
	355	void *buf = get_data(size);
	356
	357	if (buf)
	358	write_object(nr, type, buf, size);
	359	}
	360
	361	struct input_zstream_data {
	362	git_zstream *zstream;
	363	unsigned char buf[8192];
	364	int status;
	365	};
	366
	367	static const void feed_input_zstream(struct input_stream in_stream,
	368	unsigned long *readlen)
	369	{
	370	struct input_zstream_data *data = in_stream->data;
	371	git_zstream *zstream = data->zstream;
	372	void *in = fill(1);
	373
	374	if (in_stream->is_finished) {
	375	*readlen = 0;
	376	return NULL;
	377	}
	378
	379	zstream->next_out = data->buf;
	380	zstream->avail_out = sizeof(data->buf);
	381	zstream->next_in = in;
	382	zstream->avail_in = len;
	383
	384	data->status = git_inflate(zstream, 0);
	385
	386	in_stream->is_finished = data->status != Z_OK;
	387	use(len - zstream->avail_in);
	388	*readlen = sizeof(data->buf) - zstream->avail_out;
	389
	390	return data->buf;
	391	}
	392
	393	static void stream_blob(unsigned long size, unsigned nr)
	394	{
	395	git_zstream zstream = { 0 };
	396	struct input_zstream_data data = { 0 };
	397	struct input_stream in_stream = {
	398	.read = feed_input_zstream,
	399	.data = &data,
	400	};
	401	struct obj_info *info = &obj_list[nr];
	402
	403	data.zstream = &zstream;
	404	git_inflate_init(&zstream);
	405
	406	if (stream_loose_object(&in_stream, size, &info->oid))
	407	die(_("failed to write object in stream"));
	408
	409	if (data.status != Z_STREAM_END)
	410	die(_("inflate returned (%d)"), data.status);
	411	git_inflate_end(&zstream);
	412
	413	if (strict) {
	414	struct blob *blob = lookup_blob(the_repository, &info->oid);
	415
	416	if (!blob)
	417	die(_("invalid blob object from stream"));
	418	blob->object.flags \|= FLAG_WRITTEN;
	419	}
	420	info->obj = NULL;
	421	}
	422
	423	static int resolve_against_held(unsigned nr, const struct object_id *base,
	424	void *delta_data, unsigned long delta_size)
	425	{
	426	struct object *obj;
	427	struct obj_buffer *obj_buffer;
	428	obj = lookup_object(the_repository, base);
	429	if (!obj)
	430	return 0;
	431	obj_buffer = lookup_object_buffer(obj);
	432	if (!obj_buffer)
	433	return 0;
	434	resolve_delta(nr, obj->type, obj_buffer->buffer,
	435	obj_buffer->size, delta_data, delta_size);
	436	return 1;
	437	}
	438
	439	static void unpack_delta_entry(enum object_type type, unsigned long delta_size,
	440	unsigned nr)
	441	{
	442	void delta_data, base;
	443	unsigned long base_size;
	444	struct object_id base_oid;
	445
	446	if (type == OBJ_REF_DELTA) {
	447	oidread(&base_oid, fill(the_hash_algo->rawsz), the_repository->hash_algo);
	448	use(the_hash_algo->rawsz);
	449	delta_data = get_data(delta_size);
	450	if (!delta_data)
	451	return;
	452	if (has_object(the_repository, &base_oid,
	453	HAS_OBJECT_RECHECK_PACKED \| HAS_OBJECT_FETCH_PROMISOR))
	454	; /* Ok we have this one */
	455	else if (resolve_against_held(nr, &base_oid,
	456	delta_data, delta_size))
	457	return; /* we are done */
	458	else {
	459	/* cannot resolve yet --- queue it */
	460	oidclr(&obj_list[nr].oid, the_repository->hash_algo);
	461	add_delta_to_list(nr, &base_oid, 0, delta_data, delta_size);
	462	return;
	463	}
	464	} else {
	465	unsigned base_found = 0;
	466	unsigned char *pack, c;
	467	off_t base_offset;
	468	unsigned lo, mid, hi;
	469
	470	pack = fill(1);
	471	c = *pack;
	472	use(1);
	473	base_offset = c & 127;
	474	while (c & 128) {
	475	base_offset += 1;
	476	if (!base_offset \|\| MSB(base_offset, 7))
	477	die("offset value overflow for delta base object");
	478	pack = fill(1);
	479	c = *pack;
	480	use(1);
	481	base_offset = (base_offset << 7) + (c & 127);
	482	}
	483	base_offset = obj_list[nr].offset - base_offset;
	484	if (base_offset <= 0 \|\| base_offset >= obj_list[nr].offset)
	485	die("offset value out of bound for delta base object");
	486
	487	delta_data = get_data(delta_size);
	488	if (!delta_data)
	489	return;
	490	lo = 0;
	491	hi = nr;
	492	while (lo < hi) {
	493	mid = lo + (hi - lo) / 2;
	494	if (base_offset < obj_list[mid].offset) {
	495	hi = mid;
	496	} else if (base_offset > obj_list[mid].offset) {
	497	lo = mid + 1;
	498	} else {
	499	oidcpy(&base_oid, &obj_list[mid].oid);
	500	base_found = !is_null_oid(&base_oid);
	501	break;
	502	}
	503	}
	504	if (!base_found) {
	505	/*
	506	* The delta base object is itself a delta that
	507	* has not been resolved yet.
	508	*/
	509	oidclr(&obj_list[nr].oid, the_repository->hash_algo);
	510	add_delta_to_list(nr, null_oid(the_hash_algo), base_offset,
	511	delta_data, delta_size);
	512	return;
	513	}
	514	}
	515
	516	if (resolve_against_held(nr, &base_oid, delta_data, delta_size))
	517	return;
	518
	519	base = repo_read_object_file(the_repository, &base_oid, &type,
	520	&base_size);
	521	if (!base) {
	522	error("failed to read delta-pack base object %s",
	523	oid_to_hex(&base_oid));
	524	if (!recover)
	525	exit(1);
	526	has_errors = 1;
	527	return;
	528	}
	529	resolve_delta(nr, type, base, base_size, delta_data, delta_size);
	530	free(base);
	531	}
	532
	533	static void unpack_one(unsigned nr)
	534	{
	535	unsigned shift;
	536	unsigned char *pack;
	537	unsigned long size, c;
	538	enum object_type type;
	539
	540	obj_list[nr].offset = consumed_bytes;
	541
	542	pack = fill(1);
	543	c = *pack;
	544	use(1);
	545	type = (c >> 4) & 7;
	546	size = (c & 15);
	547	shift = 4;
	548	while (c & 0x80) {
	549	pack = fill(1);
	550	c = *pack;
	551	use(1);
	552	size += (c & 0x7f) << shift;
	553	shift += 7;
	554	}
	555
	556	switch (type) {
	557	case OBJ_BLOB:
	558	if (!dry_run &&
	559	size > repo_settings_get_big_file_threshold(the_repository)) {
	560	stream_blob(size, nr);
	561	return;
	562	}
	563	/* fallthrough */
	564	case OBJ_COMMIT:
	565	case OBJ_TREE:
	566	case OBJ_TAG:
	567	unpack_non_delta_entry(type, size, nr);
	568	return;
	569	case OBJ_REF_DELTA:
	570	case OBJ_OFS_DELTA:
	571	unpack_delta_entry(type, size, nr);
	572	return;
	573	default:
	574	error("bad object type %d", type);
	575	has_errors = 1;
	576	if (recover)
	577	return;
	578	exit(1);
	579	}
	580	}
	581
	582	static void unpack_all(void)
	583	{
	584	int i;
	585	unsigned char *hdr = fill(sizeof(struct pack_header));
	586
	587	if (get_be32(hdr) != PACK_SIGNATURE)
	588	die("bad pack file");
	589	hdr += 4;
	590	if (!pack_version_ok_native(get_be32(hdr)))
	591	die("unknown pack file version %"PRIu32,
	592	get_be32(hdr));
	593	hdr += 4;
	594	nr_objects = get_be32(hdr);
	595	use(sizeof(struct pack_header));
	596
	597	if (!quiet)
	598	progress = start_progress(the_repository,
	599	_("Unpacking objects"), nr_objects);
	600	CALLOC_ARRAY(obj_list, nr_objects);
	601	begin_odb_transaction();
	602	for (i = 0; i < nr_objects; i++) {
	603	unpack_one(i);
	604	display_progress(progress, i + 1);
	605	}
	606	end_odb_transaction();
	607	stop_progress(&progress);
	608
	609	if (delta_list)
	610	die("unresolved deltas left after unpacking");
	611	}
	612
	613	int cmd_unpack_objects(int argc,
	614	const char **argv,
	615	const char *prefix UNUSED,
	616	struct repository *repo UNUSED)
	617	{
	618	int i;
	619	struct object_id oid;
	620	struct git_hash_ctx tmp_ctx;
	621
	622	disable_replace_refs();
	623
	624	git_config(git_default_config, NULL);
	625
	626	quiet = !isatty(2);
	627
	628	show_usage_if_asked(argc, argv, unpack_usage);
	629
	630	for (i = 1 ; i < argc; i++) {
	631	const char *arg = argv[i];
	632
	633	if (*arg == '-') {
	634	if (!strcmp(arg, "-n")) {
	635	dry_run = 1;
	636	continue;
	637	}
	638	if (!strcmp(arg, "-q")) {
	639	quiet = 1;
	640	continue;
	641	}
	642	if (!strcmp(arg, "-r")) {
	643	recover = 1;
	644	continue;
	645	}
	646	if (!strcmp(arg, "--strict")) {
	647	strict = 1;
	648	continue;
	649	}
	650	if (skip_prefix(arg, "--strict=", &arg)) {
	651	strict = 1;
	652	fsck_set_msg_types(&fsck_options, arg);
	653	continue;
	654	}
	655	if (skip_prefix(arg, "--pack_header=", &arg)) {
	656	if (parse_pack_header_option(arg,
	657	buffer, &len) < 0)
	658	die(_("bad --pack_header: %s"), arg);
	659	continue;
	660	}
	661	if (skip_prefix(arg, "--max-input-size=", &arg)) {
	662	max_input_size = strtoumax(arg, NULL, 10);
	663	continue;
	664	}
	665	usage(unpack_usage);
	666	}
	667
	668	/* We don't take any non-flag arguments now.. Maybe some day */
	669	usage(unpack_usage);
	670	}
	671	the_hash_algo->init_fn(&ctx);
	672	unpack_all();
	673	git_hash_update(&ctx, buffer, offset);
	674	the_hash_algo->init_fn(&tmp_ctx);
	675	git_hash_clone(&tmp_ctx, &ctx);
	676	git_hash_final_oid(&oid, &tmp_ctx);
	677	if (strict) {
	678	write_rest();
	679	if (fsck_finish(&fsck_options))
	680	die(_("fsck error in pack objects"));
	681	}
	682	if (!hasheq(fill(the_hash_algo->rawsz), oid.hash,
	683	the_repository->hash_algo))
	684	die("final sha1 did not match");
	685	use(the_hash_algo->rawsz);
	686
	687	/* Write the last part of the buffer to stdout */
	688	write_in_full(1, buffer + offset, len);
	689
	690	/* All done */
	691	return has_errors;
	692	}