[thirdparty/git.git] / pack-write.c

#include "cache.h"
#include "pack.h"
#include "csum-file.h"

void reset_pack_idx_option(struct pack_idx_option *opts)
{
	memset(opts, 0, sizeof(*opts));
	opts->version = 2;
	opts->off32_limit = 0x7fffffff;
}

static int sha1_compare(const void *_a, const void *_b)
{
	struct pack_idx_entry *a = *(struct pack_idx_entry **)_a;
	struct pack_idx_entry *b = *(struct pack_idx_entry **)_b;
	return hashcmp(a->sha1, b->sha1);
}

static int cmp_uint32(const void *a_, const void *b_)
{
	uint32_t a = *((uint32_t *)a_);
	uint32_t b = *((uint32_t *)b_);

	return (a < b) ? -1 : (a != b);
}

static int need_large_offset(off_t offset, const struct pack_idx_option *opts)
{
	uint32_t ofsval;

	if ((offset >> 31) || (opts->off32_limit < offset))
		return 1;
	if (!opts->anomaly_nr)
		return 0;
	ofsval = offset;
	return !!bsearch(&ofsval, opts->anomaly, opts->anomaly_nr,
			 sizeof(ofsval), cmp_uint32);
}

/*
 * On entry *sha1 contains the pack content SHA1 hash, on exit it is
 * the SHA1 hash of sorted object names. The objects array passed in
 * will be sorted by SHA1 on exit.
 */
const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects,
			   int nr_objects, const struct pack_idx_option *opts,
			   const unsigned char *sha1)
{
	struct sha1file *f;
	struct pack_idx_entry **sorted_by_sha, **list, **last;
	off_t last_obj_offset = 0;
	uint32_t array[256];
	int i, fd;
	uint32_t index_version;

	if (nr_objects) {
		sorted_by_sha = objects;
		list = sorted_by_sha;
		last = sorted_by_sha + nr_objects;
		for (i = 0; i < nr_objects; ++i) {
			if (objects[i]->offset > last_obj_offset)
				last_obj_offset = objects[i]->offset;
		}
		qsort(sorted_by_sha, nr_objects, sizeof(sorted_by_sha[0]),
		      sha1_compare);
	}
	else
		sorted_by_sha = list = last = NULL;

	if (opts->flags & WRITE_IDX_VERIFY) {
		assert(index_name);
		f = sha1fd_check(index_name);
	} else {
		if (!index_name) {
			static char tmp_file[PATH_MAX];
			fd = odb_mkstemp(tmp_file, sizeof(tmp_file), "pack/tmp_idx_XXXXXX");
			index_name = xstrdup(tmp_file);
		} else {
			unlink(index_name);
			fd = open(index_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
		}
		if (fd < 0)
			die_errno("unable to create '%s'", index_name);
		f = sha1fd(fd, index_name);
	}

	/* if last object's offset is >= 2^31 we should use index V2 */
	index_version = need_large_offset(last_obj_offset, opts) ? 2 : opts->version;

	/* index versions 2 and above need a header */
	if (index_version >= 2) {
		struct pack_idx_header hdr;
		hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
		hdr.idx_version = htonl(index_version);
		sha1write(f, &hdr, sizeof(hdr));
	}

	/*
	 * Write the first-level table (the list is sorted,
	 * but we use a 256-entry lookup to be able to avoid
	 * having to do eight extra binary search iterations).
	 */
	for (i = 0; i < 256; i++) {
		struct pack_idx_entry **next = list;
		while (next < last) {
			struct pack_idx_entry *obj = *next;
			if (obj->sha1[0] != i)
				break;
			next++;
		}
		array[i] = htonl(next - sorted_by_sha);
		list = next;
	}
	sha1write(f, array, 256 * 4);

	/*
	 * Write the actual SHA1 entries..
	 */
	list = sorted_by_sha;
	for (i = 0; i < nr_objects; i++) {
		struct pack_idx_entry *obj = *list++;
		if (index_version < 2) {
			uint32_t offset = htonl(obj->offset);
			sha1write(f, &offset, 4);
		}
		sha1write(f, obj->sha1, 20);
		if ((opts->flags & WRITE_IDX_STRICT) &&
		    (i && !hashcmp(list[-2]->sha1, obj->sha1)))
			die("The same object %s appears twice in the pack",
			    sha1_to_hex(obj->sha1));
	}

	if (index_version >= 2) {
		unsigned int nr_large_offset = 0;

		/* write the crc32 table */
		list = sorted_by_sha;
		for (i = 0; i < nr_objects; i++) {
			struct pack_idx_entry *obj = *list++;
			uint32_t crc32_val = htonl(obj->crc32);
			sha1write(f, &crc32_val, 4);
		}

		/* write the 32-bit offset table */
		list = sorted_by_sha;
		for (i = 0; i < nr_objects; i++) {
			struct pack_idx_entry *obj = *list++;
			uint32_t offset;

			offset = (need_large_offset(obj->offset, opts)
				  ? (0x80000000 | nr_large_offset++)
				  : obj->offset);
			offset = htonl(offset);
			sha1write(f, &offset, 4);
		}

		/* write the large offset table */
		list = sorted_by_sha;
		while (nr_large_offset) {
			struct pack_idx_entry *obj = *list++;
			uint64_t offset = obj->offset;
			uint32_t split[2];

			if (!need_large_offset(offset, opts))
				continue;
			split[0] = htonl(offset >> 32);
			split[1] = htonl(offset & 0xffffffff);
			sha1write(f, split, 8);
			nr_large_offset--;
		}
	}

	sha1write(f, sha1, 20);
	sha1close(f, NULL, ((opts->flags & WRITE_IDX_VERIFY)
			    ? CSUM_CLOSE : CSUM_FSYNC));
	return index_name;
}

off_t write_pack_header(struct sha1file *f, uint32_t nr_entries)
{
	struct pack_header hdr;

	hdr.hdr_signature = htonl(PACK_SIGNATURE);
	hdr.hdr_version = htonl(PACK_VERSION);
	hdr.hdr_entries = htonl(nr_entries);
	sha1write(f, &hdr, sizeof(hdr));
	return sizeof(hdr);
}

/*
 * Update pack header with object_count and compute new SHA1 for pack data
 * associated to pack_fd, and write that SHA1 at the end.  That new SHA1
 * is also returned in new_pack_sha1.
 *
 * If partial_pack_sha1 is non null, then the SHA1 of the existing pack
 * (without the header update) is computed and validated against the
 * one provided in partial_pack_sha1.  The validation is performed at
 * partial_pack_offset bytes in the pack file.  The SHA1 of the remaining
 * data (i.e. from partial_pack_offset to the end) is then computed and
 * returned in partial_pack_sha1.
 *
 * Note that new_pack_sha1 is updated last, so both new_pack_sha1 and
 * partial_pack_sha1 can refer to the same buffer if the caller is not
 * interested in the resulting SHA1 of pack data above partial_pack_offset.
 */
void fixup_pack_header_footer(int pack_fd,
			 unsigned char *new_pack_sha1,
			 const char *pack_name,
			 uint32_t object_count,
			 unsigned char *partial_pack_sha1,
			 off_t partial_pack_offset)
{
	int aligned_sz, buf_sz = 8 * 1024;
	git_SHA_CTX old_sha1_ctx, new_sha1_ctx;
	struct pack_header hdr;
	char *buf;

	git_SHA1_Init(&old_sha1_ctx);
	git_SHA1_Init(&new_sha1_ctx);

	if (lseek(pack_fd, 0, SEEK_SET) != 0)
		die_errno("Failed seeking to start of '%s'", pack_name);
	if (read_in_full(pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
		die_errno("Unable to reread header of '%s'", pack_name);
	if (lseek(pack_fd, 0, SEEK_SET) != 0)
		die_errno("Failed seeking to start of '%s'", pack_name);
	git_SHA1_Update(&old_sha1_ctx, &hdr, sizeof(hdr));
	hdr.hdr_entries = htonl(object_count);
	git_SHA1_Update(&new_sha1_ctx, &hdr, sizeof(hdr));
	write_or_die(pack_fd, &hdr, sizeof(hdr));
	partial_pack_offset -= sizeof(hdr);

	buf = xmalloc(buf_sz);
	aligned_sz = buf_sz - sizeof(hdr);
	for (;;) {
		ssize_t m, n;
		m = (partial_pack_sha1 && partial_pack_offset < aligned_sz) ?
			partial_pack_offset : aligned_sz;
		n = xread(pack_fd, buf, m);
		if (!n)
			break;
		if (n < 0)
			die_errno("Failed to checksum '%s'", pack_name);
		git_SHA1_Update(&new_sha1_ctx, buf, n);

		aligned_sz -= n;
		if (!aligned_sz)
			aligned_sz = buf_sz;

		if (!partial_pack_sha1)
			continue;

		git_SHA1_Update(&old_sha1_ctx, buf, n);
		partial_pack_offset -= n;
		if (partial_pack_offset == 0) {
			unsigned char sha1[20];
			git_SHA1_Final(sha1, &old_sha1_ctx);
			if (hashcmp(sha1, partial_pack_sha1) != 0)
				die("Unexpected checksum for %s "
				    "(disk corruption?)", pack_name);
			/*
			 * Now let's compute the SHA1 of the remainder of the
			 * pack, which also means making partial_pack_offset
			 * big enough not to matter anymore.
			 */
			git_SHA1_Init(&old_sha1_ctx);
			partial_pack_offset = ~partial_pack_offset;
			partial_pack_offset -= MSB(partial_pack_offset, 1);
		}
	}
	free(buf);

	if (partial_pack_sha1)
		git_SHA1_Final(partial_pack_sha1, &old_sha1_ctx);
	git_SHA1_Final(new_pack_sha1, &new_sha1_ctx);
	write_or_die(pack_fd, new_pack_sha1, 20);
	fsync_or_die(pack_fd, pack_name);
}

char *index_pack_lockfile(int ip_out)
{
	char packname[46];

	/*
	 * The first thing we expect from index-pack's output
	 * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
	 * %40s is the newly created pack SHA1 name.  In the "keep"
	 * case, we need it to remove the corresponding .keep file
	 * later on.  If we don't get that then tough luck with it.
	 */
	if (read_in_full(ip_out, packname, 46) == 46 && packname[45] == '\n' &&
	    memcmp(packname, "keep\t", 5) == 0) {
		char path[PATH_MAX];
		packname[45] = 0;
		snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
			 get_object_directory(), packname + 5);
		return xstrdup(path);
	}
	return NULL;
}

/*
 * The per-object header is a pretty dense thing, which is
 *  - first byte: low four bits are "size", then three bits of "type",
 *    and the high bit is "size continues".
 *  - each byte afterwards: low seven bits are size continuation,
 *    with the high bit being "size continues"
 */
int encode_in_pack_object_header(enum object_type type, uintmax_t size, unsigned char *hdr)
{
	int n = 1;
	unsigned char c;

	if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
		die("bad type %d", type);

	c = (type << 4) | (size & 15);
	size >>= 4;
	while (size) {
		*hdr++ = c | 0x80;
		c = size & 0x7f;
		size >>= 7;
		n++;
	}
	*hdr = c;
	return n;
}

struct sha1file *create_tmp_packfile(char **pack_tmp_name)
{
	char tmpname[PATH_MAX];
	int fd;

	fd = odb_mkstemp(tmpname, sizeof(tmpname), "pack/tmp_pack_XXXXXX");
	*pack_tmp_name = xstrdup(tmpname);
	return sha1fd(fd, *pack_tmp_name);
}

void finish_tmp_packfile(struct strbuf *name_buffer,
			 const char *pack_tmp_name,
			 struct pack_idx_entry **written_list,
			 uint32_t nr_written,
			 struct pack_idx_option *pack_idx_opts,
			 unsigned char sha1[])
{
	const char *idx_tmp_name;
	int basename_len = name_buffer->len;

	if (adjust_shared_perm(pack_tmp_name))
		die_errno("unable to make temporary pack file readable");

	idx_tmp_name = write_idx_file(NULL, written_list, nr_written,
				      pack_idx_opts, sha1);
	if (adjust_shared_perm(idx_tmp_name))
		die_errno("unable to make temporary index file readable");

	strbuf_addf(name_buffer, "%s.pack", sha1_to_hex(sha1));
	free_pack_by_name(name_buffer->buf);

	if (rename(pack_tmp_name, name_buffer->buf))
		die_errno("unable to rename temporary pack file");

	strbuf_setlen(name_buffer, basename_len);

	strbuf_addf(name_buffer, "%s.idx", sha1_to_hex(sha1));
	if (rename(idx_tmp_name, name_buffer->buf))
		die_errno("unable to rename temporary index file");

	strbuf_setlen(name_buffer, basename_len);

	free((void *)idx_tmp_name);
}
Commit	Line	Data
8b0eca7c DH	1	#include "cache.h"
8b0eca7c DH	2	#include "pack.h"
aa7e44bf GB	3	#include "csum-file.h"
aa7e44bf GB	4
ebcfb379 JH	5	void reset_pack_idx_option(struct pack_idx_option *opts)
	6	{
	7	memset(opts, 0, sizeof(*opts));
	8	opts->version = 2;
	9	opts->off32_limit = 0x7fffffff;
	10	}
aa7e44bf GB	11
	12	static int sha1_compare(const void _a, const void _b)
	13	{
	14	struct pack_idx_entry a = (struct pack_idx_entry **)_a;
	15	struct pack_idx_entry b = (struct pack_idx_entry **)_b;
	16	return hashcmp(a->sha1, b->sha1);
	17	}
	18
3c9fc074 JH	19	static int cmp_uint32(const void a_, const void b_)
	20	{
	21	uint32_t a = ((uint32_t )a_);
	22	uint32_t b = ((uint32_t )b_);
	23
	24	return (a < b) ? -1 : (a != b);
	25	}
	26
fb956c1f JH	27	static int need_large_offset(off_t offset, const struct pack_idx_option *opts)
fb956c1f JH	28	{
3c9fc074 JH	29	uint32_t ofsval;
	30
	31	if ((offset >> 31) \|\| (opts->off32_limit < offset))
	32	return 1;
	33	if (!opts->anomaly_nr)
	34	return 0;
	35	ofsval = offset;
	36	return !!bsearch(&ofsval, opts->anomaly, opts->anomaly_nr,
	37	sizeof(ofsval), cmp_uint32);
fb956c1f JH	38	}
fb956c1f JH	39
aa7e44bf GB	40	/*
	41	* On entry *sha1 contains the pack content SHA1 hash, on exit it is
	42	* the SHA1 hash of sorted object names. The objects array passed in
	43	* will be sorted by SHA1 on exit.
	44	*/
3bb72562	45	const char write_idx_file(const char index_name, struct pack_idx_entry **objects,
ebcfb379	46	int nr_objects, const struct pack_idx_option *opts,
1190a1ac	47	const unsigned char *sha1)
aa7e44bf GB	48	{
	49	struct sha1file *f;
	50	struct pack_idx_entry sorted_by_sha, list, **last;
	51	off_t last_obj_offset = 0;
	52	uint32_t array[256];
	53	int i, fd;
aa7e44bf GB	54	uint32_t index_version;
	55
	56	if (nr_objects) {
	57	sorted_by_sha = objects;
	58	list = sorted_by_sha;
	59	last = sorted_by_sha + nr_objects;
	60	for (i = 0; i < nr_objects; ++i) {
	61	if (objects[i]->offset > last_obj_offset)
	62	last_obj_offset = objects[i]->offset;
	63	}
	64	qsort(sorted_by_sha, nr_objects, sizeof(sorted_by_sha[0]),
	65	sha1_compare);
	66	}
	67	else
	68	sorted_by_sha = list = last = NULL;
	69
e337a04d JH	70	if (opts->flags & WRITE_IDX_VERIFY) {
	71	assert(index_name);
	72	f = sha1fd_check(index_name);
aa7e44bf	73	} else {
e337a04d	74	if (!index_name) {
ab1900a3 ÆAB	75	static char tmp_file[PATH_MAX];
	76	fd = odb_mkstemp(tmp_file, sizeof(tmp_file), "pack/tmp_idx_XXXXXX");
	77	index_name = xstrdup(tmp_file);
e337a04d JH	78	} else {
	79	unlink(index_name);
	80	fd = open(index_name, O_CREAT\|O_EXCL\|O_WRONLY, 0600);
	81	}
	82	if (fd < 0)
	83	die_errno("unable to create '%s'", index_name);
	84	f = sha1fd(fd, index_name);
aa7e44bf	85	}
aa7e44bf GB	86
aa7e44bf GB	87	/* if last object's offset is >= 2^31 we should use index V2 */
fb956c1f	88	index_version = need_large_offset(last_obj_offset, opts) ? 2 : opts->version;
aa7e44bf GB	89
	90	/* index versions 2 and above need a header */
	91	if (index_version >= 2) {
	92	struct pack_idx_header hdr;
	93	hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
	94	hdr.idx_version = htonl(index_version);
	95	sha1write(f, &hdr, sizeof(hdr));
	96	}
	97
	98	/*
	99	* Write the first-level table (the list is sorted,
	100	* but we use a 256-entry lookup to be able to avoid
	101	* having to do eight extra binary search iterations).
	102	*/
	103	for (i = 0; i < 256; i++) {
	104	struct pack_idx_entry **next = list;
	105	while (next < last) {
	106	struct pack_idx_entry obj = next;
	107	if (obj->sha1[0] != i)
	108	break;
	109	next++;
	110	}
	111	array[i] = htonl(next - sorted_by_sha);
	112	list = next;
	113	}
	114	sha1write(f, array, 256 * 4);
	115
aa7e44bf GB	116	/*
	117	* Write the actual SHA1 entries..
	118	*/
	119	list = sorted_by_sha;
	120	for (i = 0; i < nr_objects; i++) {
	121	struct pack_idx_entry obj = list++;
	122	if (index_version < 2) {
	123	uint32_t offset = htonl(obj->offset);
	124	sha1write(f, &offset, 4);
	125	}
	126	sha1write(f, obj->sha1, 20);
68be2fea JH	127	if ((opts->flags & WRITE_IDX_STRICT) &&
	128	(i && !hashcmp(list[-2]->sha1, obj->sha1)))
	129	die("The same object %s appears twice in the pack",
	130	sha1_to_hex(obj->sha1));
aa7e44bf GB	131	}
	132
	133	if (index_version >= 2) {
	134	unsigned int nr_large_offset = 0;
	135
	136	/* write the crc32 table */
	137	list = sorted_by_sha;
	138	for (i = 0; i < nr_objects; i++) {
	139	struct pack_idx_entry obj = list++;
	140	uint32_t crc32_val = htonl(obj->crc32);
	141	sha1write(f, &crc32_val, 4);
	142	}
	143
	144	/* write the 32-bit offset table */
	145	list = sorted_by_sha;
	146	for (i = 0; i < nr_objects; i++) {
	147	struct pack_idx_entry obj = list++;
fb956c1f JH	148	uint32_t offset;
	149
	150	offset = (need_large_offset(obj->offset, opts)
	151	? (0x80000000 \| nr_large_offset++)
	152	: obj->offset);
aa7e44bf GB	153	offset = htonl(offset);
	154	sha1write(f, &offset, 4);
	155	}
	156
	157	/* write the large offset table */
	158	list = sorted_by_sha;
	159	while (nr_large_offset) {
	160	struct pack_idx_entry obj = list++;
	161	uint64_t offset = obj->offset;
fb956c1f JH	162	uint32_t split[2];
	163
	164	if (!need_large_offset(offset, opts))
	165	continue;
	166	split[0] = htonl(offset >> 32);
	167	split[1] = htonl(offset & 0xffffffff);
	168	sha1write(f, split, 8);
	169	nr_large_offset--;
aa7e44bf GB	170	}
	171	}
	172
	173	sha1write(f, sha1, 20);
e337a04d JH	174	sha1close(f, NULL, ((opts->flags & WRITE_IDX_VERIFY)
e337a04d JH	175	? CSUM_CLOSE : CSUM_FSYNC));
aa7e44bf GB	176	return index_name;
aa7e44bf GB	177	}
8b0eca7c	178
c0ad4657 JH	179	off_t write_pack_header(struct sha1file *f, uint32_t nr_entries)
	180	{
	181	struct pack_header hdr;
	182
	183	hdr.hdr_signature = htonl(PACK_SIGNATURE);
	184	hdr.hdr_version = htonl(PACK_VERSION);
	185	hdr.hdr_entries = htonl(nr_entries);
9af270e8	186	sha1write(f, &hdr, sizeof(hdr));
c0ad4657 JH	187	return sizeof(hdr);
	188	}
	189
abeb40e5 NP	190	/*
	191	* Update pack header with object_count and compute new SHA1 for pack data
	192	* associated to pack_fd, and write that SHA1 at the end. That new SHA1
	193	* is also returned in new_pack_sha1.
	194	*
	195	* If partial_pack_sha1 is non null, then the SHA1 of the existing pack
	196	* (without the header update) is computed and validated against the
	197	* one provided in partial_pack_sha1. The validation is performed at
	198	* partial_pack_offset bytes in the pack file. The SHA1 of the remaining
	199	* data (i.e. from partial_pack_offset to the end) is then computed and
	200	* returned in partial_pack_sha1.
	201	*
	202	* Note that new_pack_sha1 is updated last, so both new_pack_sha1 and
	203	* partial_pack_sha1 can refer to the same buffer if the caller is not
	204	* interested in the resulting SHA1 of pack data above partial_pack_offset.
	205	*/
8b0eca7c	206	void fixup_pack_header_footer(int pack_fd,
abeb40e5	207	unsigned char *new_pack_sha1,
8b0eca7c	208	const char *pack_name,
abeb40e5 NP	209	uint32_t object_count,
	210	unsigned char *partial_pack_sha1,
	211	off_t partial_pack_offset)
8b0eca7c	212	{
d35825da	213	int aligned_sz, buf_sz = 8 * 1024;
9126f009	214	git_SHA_CTX old_sha1_ctx, new_sha1_ctx;
8b0eca7c DH	215	struct pack_header hdr;
	216	char *buf;
	217
9126f009 NP	218	git_SHA1_Init(&old_sha1_ctx);
9126f009 NP	219	git_SHA1_Init(&new_sha1_ctx);
abeb40e5	220
8b0eca7c	221	if (lseek(pack_fd, 0, SEEK_SET) != 0)
d824cbba	222	die_errno("Failed seeking to start of '%s'", pack_name);
8b0eca7c	223	if (read_in_full(pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
d824cbba	224	die_errno("Unable to reread header of '%s'", pack_name);
8b0eca7c	225	if (lseek(pack_fd, 0, SEEK_SET) != 0)
d824cbba	226	die_errno("Failed seeking to start of '%s'", pack_name);
9126f009	227	git_SHA1_Update(&old_sha1_ctx, &hdr, sizeof(hdr));
8b0eca7c	228	hdr.hdr_entries = htonl(object_count);
9126f009	229	git_SHA1_Update(&new_sha1_ctx, &hdr, sizeof(hdr));
8b0eca7c	230	write_or_die(pack_fd, &hdr, sizeof(hdr));
abeb40e5	231	partial_pack_offset -= sizeof(hdr);
8b0eca7c DH	232
8b0eca7c DH	233	buf = xmalloc(buf_sz);
d35825da	234	aligned_sz = buf_sz - sizeof(hdr);
8b0eca7c	235	for (;;) {
abeb40e5	236	ssize_t m, n;
d35825da NP	237	m = (partial_pack_sha1 && partial_pack_offset < aligned_sz) ?
d35825da NP	238	partial_pack_offset : aligned_sz;
abeb40e5	239	n = xread(pack_fd, buf, m);
8b0eca7c DH	240	if (!n)
	241	break;
	242	if (n < 0)
d824cbba	243	die_errno("Failed to checksum '%s'", pack_name);
9126f009	244	git_SHA1_Update(&new_sha1_ctx, buf, n);
abeb40e5	245
d35825da NP	246	aligned_sz -= n;
	247	if (!aligned_sz)
	248	aligned_sz = buf_sz;
	249
abeb40e5 NP	250	if (!partial_pack_sha1)
	251	continue;
	252
9126f009	253	git_SHA1_Update(&old_sha1_ctx, buf, n);
abeb40e5 NP	254	partial_pack_offset -= n;
	255	if (partial_pack_offset == 0) {
	256	unsigned char sha1[20];
9126f009	257	git_SHA1_Final(sha1, &old_sha1_ctx);
abeb40e5 NP	258	if (hashcmp(sha1, partial_pack_sha1) != 0)
	259	die("Unexpected checksum for %s "
	260	"(disk corruption?)", pack_name);
	261	/*
	262	* Now let's compute the SHA1 of the remainder of the
	263	* pack, which also means making partial_pack_offset
	264	* big enough not to matter anymore.
	265	*/
9126f009	266	git_SHA1_Init(&old_sha1_ctx);
abeb40e5 NP	267	partial_pack_offset = ~partial_pack_offset;
	268	partial_pack_offset -= MSB(partial_pack_offset, 1);
	269	}
8b0eca7c DH	270	}
	271	free(buf);
	272
abeb40e5	273	if (partial_pack_sha1)
9126f009 NP	274	git_SHA1_Final(partial_pack_sha1, &old_sha1_ctx);
9126f009 NP	275	git_SHA1_Final(new_pack_sha1, &new_sha1_ctx);
abeb40e5	276	write_or_die(pack_fd, new_pack_sha1, 20);
0c68d386	277	fsync_or_die(pack_fd, pack_name);
8b0eca7c	278	}
106764e6 SP	279
	280	char *index_pack_lockfile(int ip_out)
	281	{
106764e6 SP	282	char packname[46];
	283
	284	/*
6e180cdc	285	* The first thing we expect from index-pack's output
106764e6 SP	286	* is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
	287	* %40s is the newly created pack SHA1 name. In the "keep"
	288	* case, we need it to remove the corresponding .keep file
	289	* later on. If we don't get that then tough luck with it.
	290	*/
c697ad14 HO	291	if (read_in_full(ip_out, packname, 46) == 46 && packname[45] == '\n' &&
c697ad14 HO	292	memcmp(packname, "keep\t", 5) == 0) {
106764e6 SP	293	char path[PATH_MAX];
	294	packname[45] = 0;
	295	snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
	296	get_object_directory(), packname + 5);
	297	return xstrdup(path);
	298	}
	299	return NULL;
	300	}
f965c525 NP	301
	302	/*
	303	* The per-object header is a pretty dense thing, which is
	304	* - first byte: low four bits are "size", then three bits of "type",
	305	* and the high bit is "size continues".
	306	* - each byte afterwards: low seven bits are size continuation,
	307	* with the high bit being "size continues"
	308	*/
	309	int encode_in_pack_object_header(enum object_type type, uintmax_t size, unsigned char *hdr)
	310	{
	311	int n = 1;
	312	unsigned char c;
	313
	314	if (type < OBJ_COMMIT \|\| type > OBJ_REF_DELTA)
	315	die("bad type %d", type);
	316
	317	c = (type << 4) \| (size & 15);
	318	size >>= 4;
	319	while (size) {
	320	*hdr++ = c \| 0x80;
	321	c = size & 0x7f;
	322	size >>= 7;
	323	n++;
	324	}
	325	*hdr = c;
	326	return n;
	327	}
cdf9db3c JH	328
	329	struct sha1file create_tmp_packfile(char *pack_tmp_name)
	330	{
	331	char tmpname[PATH_MAX];
	332	int fd;
	333
	334	fd = odb_mkstemp(tmpname, sizeof(tmpname), "pack/tmp_pack_XXXXXX");
	335	*pack_tmp_name = xstrdup(tmpname);
	336	return sha1fd(fd, *pack_tmp_name);
	337	}
0e990530	338
58892711	339	void finish_tmp_packfile(struct strbuf *name_buffer,
0e990530 JH	340	const char *pack_tmp_name,
	341	struct pack_idx_entry **written_list,
	342	uint32_t nr_written,
	343	struct pack_idx_option *pack_idx_opts,
	344	unsigned char sha1[])
	345	{
	346	const char *idx_tmp_name;
58892711	347	int basename_len = name_buffer->len;
0e990530 JH	348
	349	if (adjust_shared_perm(pack_tmp_name))
	350	die_errno("unable to make temporary pack file readable");
	351
	352	idx_tmp_name = write_idx_file(NULL, written_list, nr_written,
	353	pack_idx_opts, sha1);
	354	if (adjust_shared_perm(idx_tmp_name))
	355	die_errno("unable to make temporary index file readable");
	356
58892711 SH	357	strbuf_addf(name_buffer, "%s.pack", sha1_to_hex(sha1));
58892711 SH	358	free_pack_by_name(name_buffer->buf);
0e990530	359
58892711	360	if (rename(pack_tmp_name, name_buffer->buf))
0e990530 JH	361	die_errno("unable to rename temporary pack file");
0e990530 JH	362
58892711 SH	363	strbuf_setlen(name_buffer, basename_len);
	364
	365	strbuf_addf(name_buffer, "%s.idx", sha1_to_hex(sha1));
	366	if (rename(idx_tmp_name, name_buffer->buf))
0e990530 JH	367	die_errno("unable to rename temporary index file");
0e990530 JH	368
58892711	369	strbuf_setlen(name_buffer, basename_len);
7cc8f971	370
0e990530 JH	371	free((void *)idx_tmp_name);
0e990530 JH	372	}