-static int sha1_sort(const void *_a, const void *_b)
-{
- const struct object_entry *a = *(struct object_entry **)_a;
- const struct object_entry *b = *(struct object_entry **)_b;
- return hashcmp(a->sha1, b->sha1);
-}
-
-static uint32_t index_default_version = 1;
-static uint32_t index_off32_limit = 0x7fffffff;
-
-static void write_index_file(off_t last_obj_offset, unsigned char *sha1)
-{
- struct sha1file *f;
- struct object_entry **sorted_by_sha, **list, **last;
- uint32_t array[256];
- uint32_t i, index_version;
- SHA_CTX ctx;
-
- int fd = open_object_dir_tmp("tmp_idx_XXXXXX");
- if (fd < 0)
- die("unable to create %s: %s\n", tmpname, strerror(errno));
- idx_tmp_name = xstrdup(tmpname);
- f = sha1fd(fd, idx_tmp_name);
-
- if (nr_written) {
- sorted_by_sha = written_list;
- qsort(sorted_by_sha, nr_written, sizeof(*sorted_by_sha), sha1_sort);
- list = sorted_by_sha;
- last = sorted_by_sha + nr_written;
- } else
- sorted_by_sha = list = last = NULL;
-
- /* if last object's offset is >= 2^31 we should use index V2 */
- index_version = (last_obj_offset >> 31) ? 2 : index_default_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 object_entry **next = list;
- while (next < last) {
- struct object_entry *entry = *next;
- if (entry->sha1[0] != i)
- break;
- next++;
- }
- array[i] = htonl(next - sorted_by_sha);
- list = next;
- }
- sha1write(f, array, 256 * 4);
-
- /* Compute the SHA1 hash of sorted object names. */
- SHA1_Init(&ctx);
-
- /* Write the actual SHA1 entries. */
- list = sorted_by_sha;
- for (i = 0; i < nr_written; i++) {
- struct object_entry *entry = *list++;
- if (index_version < 2) {
- uint32_t offset = htonl(entry->offset);
- sha1write(f, &offset, 4);
- }
- sha1write(f, entry->sha1, 20);
- SHA1_Update(&ctx, entry->sha1, 20);
- }
-
- if (index_version >= 2) {
- unsigned int nr_large_offset = 0;
-
- /* write the crc32 table */
- list = sorted_by_sha;
- for (i = 0; i < nr_written; i++) {
- struct object_entry *entry = *list++;
- uint32_t crc32_val = htonl(entry->crc32);
- sha1write(f, &crc32_val, 4);
- }
-
- /* write the 32-bit offset table */
- list = sorted_by_sha;
- for (i = 0; i < nr_written; i++) {
- struct object_entry *entry = *list++;
- uint32_t offset = (entry->offset <= index_off32_limit) ?
- entry->offset : (0x80000000 | nr_large_offset++);
- offset = htonl(offset);
- sha1write(f, &offset, 4);
- }
-
- /* write the large offset table */
- list = sorted_by_sha;
- while (nr_large_offset) {
- struct object_entry *entry = *list++;
- uint64_t offset = entry->offset;
- if (offset > index_off32_limit) {
- uint32_t split[2];
- split[0] = htonl(offset >> 32);
- split[1] = htonl(offset & 0xffffffff);
- sha1write(f, split, 8);
- nr_large_offset--;
- }
- }
- }
-
- sha1write(f, pack_file_sha1, 20);
- sha1close(f, NULL, 1);
- SHA1_Final(sha1, &ctx);
-}
-