| #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); | |
| } | |
| /* | |
| * 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, 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) { | |
| 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 = 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->oid.hash[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->oid.hash, 20); | |
| if ((opts->flags & WRITE_IDX_STRICT) && | |
| (i && !oidcmp(&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++; | |
| 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') { | |
| const char *name; | |
| packname[45] = 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 sha1file *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 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)); | |
| 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); | |
| } |
