diff options
Diffstat (limited to 'third_party/git/pack-write.c')
-rw-r--r-- | third_party/git/pack-write.c | 374 |
1 files changed, 0 insertions, 374 deletions
diff --git a/third_party/git/pack-write.c b/third_party/git/pack-write.c deleted file mode 100644 index a6cdb3c67cca..000000000000 --- a/third_party/git/pack-write.c +++ /dev/null @@ -1,374 +0,0 @@ -#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 oidcmp(&a->oid, &b->oid); -} - -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); -} - -/* - * The *sha1 contains the pack content SHA1 hash. - * 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 hashfile *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, sha1_compare); - } - else - sorted_by_sha = list = last = NULL; - - if (opts->flags & WRITE_IDX_VERIFY) { - assert(index_name); - f = hashfd_check(index_name); - } else { - if (!index_name) { - struct strbuf tmp_file = STRBUF_INIT; - fd = odb_mkstemp(&tmp_file, "pack/tmp_idx_XXXXXX"); - index_name = strbuf_detach(&tmp_file, NULL); - } 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 = hashfd(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; - while (next < last) { - struct pack_idx_entry *obj = *next; - if (obj->oid.hash[0] != i) - break; - next++; - } - array[i] = htonl(next - sorted_by_sha); - list = next; - } - hashwrite(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) - hashwrite_be32(f, obj->offset); - hashwrite(f, obj->oid.hash, the_hash_algo->rawsz); - if ((opts->flags & WRITE_IDX_STRICT) && - (i && oideq(&list[-2]->oid, &obj->oid))) - die("The same object %s appears twice in the pack", - oid_to_hex(&obj->oid)); - } - - 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++; - hashwrite_be32(f, obj->crc32); - } - - /* 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); - hashwrite_be32(f, offset); - } - - /* 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); - hashwrite(f, split, 8); - nr_large_offset--; - } - } - - hashwrite(f, sha1, the_hash_algo->rawsz); - finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_CLOSE | - ((opts->flags & WRITE_IDX_VERIFY) - ? 0 : CSUM_FSYNC)); - return index_name; -} - -off_t write_pack_header(struct hashfile *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); - hashwrite(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_hash, - const char *pack_name, - uint32_t object_count, - unsigned char *partial_pack_hash, - off_t partial_pack_offset) -{ - int aligned_sz, buf_sz = 8 * 1024; - git_hash_ctx old_hash_ctx, new_hash_ctx; - struct pack_header hdr; - char *buf; - ssize_t read_result; - - the_hash_algo->init_fn(&old_hash_ctx); - the_hash_algo->init_fn(&new_hash_ctx); - - if (lseek(pack_fd, 0, SEEK_SET) != 0) - die_errno("Failed seeking to start of '%s'", pack_name); - read_result = read_in_full(pack_fd, &hdr, sizeof(hdr)); - if (read_result < 0) - die_errno("Unable to reread header of '%s'", pack_name); - else if (read_result != sizeof(hdr)) - die_errno("Unexpected short read for header of '%s'", - pack_name); - if (lseek(pack_fd, 0, SEEK_SET) != 0) - die_errno("Failed seeking to start of '%s'", pack_name); - the_hash_algo->update_fn(&old_hash_ctx, &hdr, sizeof(hdr)); - hdr.hdr_entries = htonl(object_count); - the_hash_algo->update_fn(&new_hash_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_hash && 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); - the_hash_algo->update_fn(&new_hash_ctx, buf, n); - - aligned_sz -= n; - if (!aligned_sz) - aligned_sz = buf_sz; - - if (!partial_pack_hash) - continue; - - the_hash_algo->update_fn(&old_hash_ctx, buf, n); - partial_pack_offset -= n; - if (partial_pack_offset == 0) { - unsigned char hash[GIT_MAX_RAWSZ]; - the_hash_algo->final_fn(hash, &old_hash_ctx); - if (!hasheq(hash, partial_pack_hash)) - 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. - */ - the_hash_algo->init_fn(&old_hash_ctx); - partial_pack_offset = ~partial_pack_offset; - partial_pack_offset -= MSB(partial_pack_offset, 1); - } - } - free(buf); - - if (partial_pack_hash) - the_hash_algo->final_fn(partial_pack_hash, &old_hash_ctx); - the_hash_algo->final_fn(new_pack_hash, &new_hash_ctx); - write_or_die(pack_fd, new_pack_hash, the_hash_algo->rawsz); - fsync_or_die(pack_fd, pack_name); -} - -char *index_pack_lockfile(int ip_out) -{ - char packname[GIT_MAX_HEXSZ + 6]; - const int len = the_hash_algo->hexsz + 6; - - /* - * 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, len) == len && packname[len-1] == '\n') { - const char *name; - packname[len-1] = 0; - if (skip_prefix(packname, "keep\t", &name)) - return xstrfmt("%s/pack/pack-%s.keep", - get_object_directory(), name); - } - 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(unsigned char *hdr, int hdr_len, - enum object_type type, uintmax_t size) -{ - 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) { - if (n == hdr_len) - die("object size is too enormous to format"); - *hdr++ = c | 0x80; - c = size & 0x7f; - size >>= 7; - n++; - } - *hdr = c; - return n; -} - -struct hashfile *create_tmp_packfile(char **pack_tmp_name) -{ - struct strbuf tmpname = STRBUF_INIT; - int fd; - - fd = odb_mkstemp(&tmpname, "pack/tmp_pack_XXXXXX"); - *pack_tmp_name = strbuf_detach(&tmpname, NULL); - return hashfd(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 hash[]) -{ - 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, hash); - if (adjust_shared_perm(idx_tmp_name)) - die_errno("unable to make temporary index file readable"); - - strbuf_addf(name_buffer, "%s.pack", hash_to_hex(hash)); - - 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", hash_to_hex(hash)); - 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); -} |