Function write_idx_file

pack-write.c:57–180

* The *sha1 contains the pack content SHA1 hash. * The objects array passed in will be sorted by SHA1 on exit. */

 * The objects array passed in will be sorted by SHA1 on exit.
 */
const char *write_idx_file(struct repository *repo,
			   const char *index_name, struct pack_idx_entry **objects,
			   int nr_objects, const struct pack_idx_option *opts,
			   const unsigned char *sha1)
{
	struct hashfile *f;
	struct pack_idx_entry **sorted_by_sha, **list, **last;
	off_t last_obj_offset = 0;
	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, sha1_compare);
	}
	else
		sorted_by_sha = list = last = NULL;

	if (opts->flags & WRITE_IDX_VERIFY) {
		assert(index_name);
		f = hashfd_check(repo->hash_algo, index_name);
	} else {
		if (!index_name) {
			struct strbuf tmp_file = STRBUF_INIT;
			fd = odb_mkstemp(repo->objects, &tmp_file,
					 "pack/tmp_idx_XXXXXX");
			index_name = strbuf_detach(&tmp_file, NULL);
		} else {
			unlink(index_name);
			fd = xopen(index_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
		}
		f = hashfd(repo->hash_algo, 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);
		hashwrite(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;