diff options
Diffstat (limited to 'sha1_file.c')
-rw-r--r-- | sha1_file.c | 311 |
1 files changed, 155 insertions, 156 deletions
diff --git a/sha1_file.c b/sha1_file.c index dae6433c06..a38854ce55 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -60,6 +60,12 @@ static struct cached_object empty_tree = { 0 }; +/* + * A pointer to the last packed_git in which an object was found. + * When an object is sought, we look in this packfile first, because + * objects that are looked up at similar times are often in the same + * packfile as one another. + */ static struct packed_git *last_found_pack; static struct cached_object *find_cached_object(const unsigned char *sha1) @@ -105,50 +111,63 @@ int mkdir_in_gitdir(const char *path) return adjust_shared_perm(path); } -int safe_create_leading_directories(char *path) +enum scld_error safe_create_leading_directories(char *path) { - char *pos = path + offset_1st_component(path); - struct stat st; + char *next_component = path + offset_1st_component(path); + enum scld_error ret = SCLD_OK; + + while (ret == SCLD_OK && next_component) { + struct stat st; + char *slash = next_component, slash_character; + + while (*slash && !is_dir_sep(*slash)) + slash++; - while (pos) { - pos = strchr(pos, '/'); - if (!pos) + if (!*slash) break; - while (*++pos == '/') - ; - if (!*pos) + + next_component = slash + 1; + while (is_dir_sep(*next_component)) + next_component++; + if (!*next_component) break; - *--pos = '\0'; + + slash_character = *slash; + *slash = '\0'; if (!stat(path, &st)) { /* path exists */ - if (!S_ISDIR(st.st_mode)) { - *pos = '/'; - return -3; - } - } - else if (mkdir(path, 0777)) { + if (!S_ISDIR(st.st_mode)) + ret = SCLD_EXISTS; + } else if (mkdir(path, 0777)) { if (errno == EEXIST && - !stat(path, &st) && S_ISDIR(st.st_mode)) { + !stat(path, &st) && S_ISDIR(st.st_mode)) ; /* somebody created it since we checked */ - } else { - *pos = '/'; - return -1; - } - } - else if (adjust_shared_perm(path)) { - *pos = '/'; - return -2; + else if (errno == ENOENT) + /* + * Either mkdir() failed because + * somebody just pruned the containing + * directory, or stat() failed because + * the file that was in our way was + * just removed. Either way, inform + * the caller that it might be worth + * trying again: + */ + ret = SCLD_VANISHED; + else + ret = SCLD_FAILED; + } else if (adjust_shared_perm(path)) { + ret = SCLD_PERMS; } - *pos++ = '/'; + *slash = slash_character; } - return 0; + return ret; } -int safe_create_leading_directories_const(const char *path) +enum scld_error safe_create_leading_directories_const(const char *path) { /* path points to cache entries, so xstrdup before messing with it */ char *buf = xstrdup(path); - int result = safe_create_leading_directories(buf); + enum scld_error result = safe_create_leading_directories(buf); free(buf); return result; } @@ -165,17 +184,7 @@ static void fill_sha1_path(char *pathbuf, const unsigned char *sha1) } } -/* - * NOTE! This returns a statically allocated buffer, so you have to be - * careful about using it. Do an "xstrdup()" if you need to save the - * filename. - * - * Also note that this returns the location for creating. Reading - * SHA1 file can happen from any alternate directory listed in the - * DB_ENVIRONMENT environment variable if it is not found in - * the primary object database. - */ -char *sha1_file_name(const unsigned char *sha1) +const char *sha1_file_name(const unsigned char *sha1) { static char buf[PATH_MAX]; const char *objdir; @@ -195,6 +204,11 @@ char *sha1_file_name(const unsigned char *sha1) return buf; } +/* + * Return the name of the pack or index file with the specified sha1 + * in its filename. *base and *name are scratch space that must be + * provided by the caller. which should be "pack" or "idx". + */ static char *sha1_get_pack_name(const unsigned char *sha1, char **name, char **base, const char *which) { @@ -239,8 +253,6 @@ char *sha1_pack_index_name(const unsigned char *sha1) struct alternate_object_database *alt_odb_list; static struct alternate_object_database **alt_odb_tail; -static int git_open_noatime(const char *name); - /* * Prepare alternate object database registry. * @@ -426,8 +438,7 @@ void prepare_alt_odb(void) static int has_loose_object_local(const unsigned char *sha1) { - char *name = sha1_file_name(sha1); - return !access(name, F_OK); + return !access(sha1_file_name(sha1), F_OK); } int has_loose_object_nonlocal(const unsigned char *sha1) @@ -479,7 +490,12 @@ void pack_report(void) sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped)); } -static int check_packed_git_idx(const char *path, struct packed_git *p) +/* + * Open and mmap the index file at path, perform a couple of + * consistency checks, then record its information to p. Return 0 on + * success. + */ +static int check_packed_git_idx(const char *path, struct packed_git *p) { void *idx_map; struct pack_idx_header *hdr; @@ -775,7 +791,7 @@ void close_pack_index(struct packed_git *p) * contain the same set of objects as an existing one. In that case * the resulting file might be different even if its name would be the * same. It is best to close any reference to the old pack before it is - * replaced on disk. Of course no index pointers nor windows for given pack + * replaced on disk. Of course no index pointers or windows for given pack * must subsist at this point. If ever objects from this pack are requested * again, the new version of the pack will be reinitialized through * reprepare_packed_git(). @@ -1111,7 +1127,7 @@ static void report_helper(const struct string_list *list, const char *msg; switch (seen_bits) { case 0: - msg = "no corresponding .idx nor .pack"; + msg = "no corresponding .idx or .pack"; break; case 1: msg = "no corresponding .idx"; @@ -1220,6 +1236,7 @@ static void prepare_packed_git_one(char *objdir, int local) if (has_extension(de->d_name, ".idx") || has_extension(de->d_name, ".pack") || + has_extension(de->d_name, ".bitmap") || has_extension(de->d_name, ".keep")) string_list_append(&garbage, path); else @@ -1304,7 +1321,6 @@ void prepare_packed_git(void) void reprepare_packed_git(void) { - discard_revindex(); prepare_packed_git_run_once = 0; prepare_packed_git(); } @@ -1381,7 +1397,7 @@ int check_sha1_signature(const unsigned char *sha1, void *map, return hashcmp(sha1, real_sha1) ? -1 : 0; } -static int git_open_noatime(const char *name) +int git_open_noatime(const char *name) { static int sha1_file_open_flag = O_NOATIME; @@ -1402,17 +1418,15 @@ static int git_open_noatime(const char *name) static int stat_sha1_file(const unsigned char *sha1, struct stat *st) { - char *name = sha1_file_name(sha1); struct alternate_object_database *alt; - if (!lstat(name, st)) + if (!lstat(sha1_file_name(sha1), st)) return 0; prepare_alt_odb(); errno = ENOENT; for (alt = alt_odb_list; alt; alt = alt->next) { - name = alt->name; - fill_sha1_path(name, sha1); + fill_sha1_path(alt->name, sha1); if (!lstat(alt->base, st)) return 0; } @@ -1423,22 +1437,24 @@ static int stat_sha1_file(const unsigned char *sha1, struct stat *st) static int open_sha1_file(const unsigned char *sha1) { int fd; - char *name = sha1_file_name(sha1); struct alternate_object_database *alt; + int most_interesting_errno; - fd = git_open_noatime(name); + fd = git_open_noatime(sha1_file_name(sha1)); if (fd >= 0) return fd; + most_interesting_errno = errno; prepare_alt_odb(); - errno = ENOENT; for (alt = alt_odb_list; alt; alt = alt->next) { - name = alt->name; - fill_sha1_path(name, sha1); + fill_sha1_path(alt->name, sha1); fd = git_open_noatime(alt->base); if (fd >= 0) return fd; + if (most_interesting_errno == ENOENT) + most_interesting_errno = errno; } + errno = most_interesting_errno; return -1; } @@ -1466,51 +1482,6 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size) return map; } -/* - * There used to be a second loose object header format which - * was meant to mimic the in-pack format, allowing for direct - * copy of the object data. This format turned up not to be - * really worth it and we no longer write loose objects in that - * format. - */ -static int experimental_loose_object(unsigned char *map) -{ - unsigned int word; - - /* - * We must determine if the buffer contains the standard - * zlib-deflated stream or the experimental format based - * on the in-pack object format. Compare the header byte - * for each format: - * - * RFC1950 zlib w/ deflate : 0www1000 : 0 <= www <= 7 - * Experimental pack-based : Stttssss : ttt = 1,2,3,4 - * - * If bit 7 is clear and bits 0-3 equal 8, the buffer MUST be - * in standard loose-object format, UNLESS it is a Git-pack - * format object *exactly* 8 bytes in size when inflated. - * - * However, RFC1950 also specifies that the 1st 16-bit word - * must be divisible by 31 - this checksum tells us our buffer - * is in the standard format, giving a false positive only if - * the 1st word of the Git-pack format object happens to be - * divisible by 31, ie: - * ((byte0 * 256) + byte1) % 31 = 0 - * => 0ttt10000www1000 % 31 = 0 - * - * As it happens, this case can only arise for www=3 & ttt=1 - * - ie, a Commit object, which would have to be 8 bytes in - * size. As no Commit can be that small, we find that the - * combination of these two criteria (bitmask & checksum) - * can always correctly determine the buffer format. - */ - word = (map[0] << 8) + map[1]; - if ((map[0] & 0x8F) == 0x08 && !(word % 31)) - return 0; - else - return 1; -} - unsigned long unpack_object_header_buffer(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep) { @@ -1538,14 +1509,6 @@ unsigned long unpack_object_header_buffer(const unsigned char *buf, int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz) { - unsigned long size, used; - static const char valid_loose_object_type[8] = { - 0, /* OBJ_EXT */ - 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */ - 0, /* "delta" and others are invalid in a loose object */ - }; - enum object_type type; - /* Get the data stream */ memset(stream, 0, sizeof(*stream)); stream->next_in = map; @@ -1553,27 +1516,6 @@ int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long ma stream->next_out = buffer; stream->avail_out = bufsiz; - if (experimental_loose_object(map)) { - /* - * The old experimental format we no longer produce; - * we can still read it. - */ - used = unpack_object_header_buffer(map, mapsize, &type, &size); - if (!used || !valid_loose_object_type[type]) - return -1; - map += used; - mapsize -= used; - - /* Set up the stream for the rest.. */ - stream->next_in = map; - stream->avail_in = mapsize; - git_inflate_init(stream); - - /* And generate the fake traditional header */ - stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu", - typename(type), size); - return 0; - } git_inflate_init(stream); return git_inflate(stream, 0); } @@ -1765,6 +1707,38 @@ static off_t get_delta_base(struct packed_git *p, return base_offset; } +/* + * Like get_delta_base above, but we return the sha1 instead of the pack + * offset. This means it is cheaper for REF deltas (we do not have to do + * the final object lookup), but more expensive for OFS deltas (we + * have to load the revidx to convert the offset back into a sha1). + */ +static const unsigned char *get_delta_base_sha1(struct packed_git *p, + struct pack_window **w_curs, + off_t curpos, + enum object_type type, + off_t delta_obj_offset) +{ + if (type == OBJ_REF_DELTA) { + unsigned char *base = use_pack(p, w_curs, curpos, NULL); + return base; + } else if (type == OBJ_OFS_DELTA) { + struct revindex_entry *revidx; + off_t base_offset = get_delta_base(p, w_curs, &curpos, + type, delta_obj_offset); + + if (!base_offset) + return NULL; + + revidx = find_pack_revindex(p, base_offset); + if (!revidx) + return NULL; + + return nth_packed_object_sha1(p, revidx->nr); + } else + return NULL; +} + int unpack_object_header(struct packed_git *p, struct pack_window **w_curs, off_t *curpos, @@ -1922,6 +1896,22 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset, } } + if (oi->delta_base_sha1) { + if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) { + const unsigned char *base; + + base = get_delta_base_sha1(p, &w_curs, curpos, + type, obj_offset); + if (!base) { + type = OBJ_BAD; + goto out; + } + + hashcpy(oi->delta_base_sha1, base); + } else + hashclr(oi->delta_base_sha1); + } + out: unuse_pack(&w_curs); return type; @@ -2303,6 +2293,10 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset, *final_size = size; unuse_pack(&w_curs); + + if (delta_stack != small_delta_stack) + free(delta_stack); + return data; } @@ -2462,6 +2456,10 @@ static int fill_pack_entry(const unsigned char *sha1, return 1; } +/* + * Iff a pack file contains the object named by sha1, return true and + * store its location to e. + */ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e) { struct packed_git *p; @@ -2474,11 +2472,13 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e) return 1; for (p = packed_git; p; p = p->next) { - if (p == last_found_pack || !fill_pack_entry(sha1, e, p)) - continue; + if (p == last_found_pack) + continue; /* we already checked this one */ - last_found_pack = p; - return 1; + if (fill_pack_entry(sha1, e, p)) { + last_found_pack = p; + return 1; + } } return 0; } @@ -2505,6 +2505,9 @@ static int sha1_loose_object_info(const unsigned char *sha1, git_zstream stream; char hdr[32]; + if (oi->delta_base_sha1) + hashclr(oi->delta_base_sha1); + /* * If we don't care about type or size, then we don't * need to look inside the object at all. Note that we @@ -2541,13 +2544,14 @@ static int sha1_loose_object_info(const unsigned char *sha1, return 0; } -int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi) +int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags) { struct cached_object *co; struct pack_entry e; int rtype; + const unsigned char *real = lookup_replace_object_extended(sha1, flags); - co = find_cached_object(sha1); + co = find_cached_object(real); if (co) { if (oi->typep) *(oi->typep) = co->type; @@ -2555,27 +2559,29 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi) *(oi->sizep) = co->size; if (oi->disk_sizep) *(oi->disk_sizep) = 0; + if (oi->delta_base_sha1) + hashclr(oi->delta_base_sha1); oi->whence = OI_CACHED; return 0; } - if (!find_pack_entry(sha1, &e)) { + if (!find_pack_entry(real, &e)) { /* Most likely it's a loose object. */ - if (!sha1_loose_object_info(sha1, oi)) { + if (!sha1_loose_object_info(real, oi)) { oi->whence = OI_LOOSE; return 0; } /* Not a loose object; someone else may have just packed it. */ reprepare_packed_git(); - if (!find_pack_entry(sha1, &e)) + if (!find_pack_entry(real, &e)) return -1; } rtype = packed_object_info(e.p, e.offset, oi); if (rtype < 0) { - mark_bad_packed_object(e.p, sha1); - return sha1_object_info_extended(sha1, oi); + mark_bad_packed_object(e.p, real); + return sha1_object_info_extended(real, oi, 0); } else if (in_delta_base_cache(e.p, e.offset)) { oi->whence = OI_DBCACHED; } else { @@ -2597,7 +2603,7 @@ int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) oi.typep = &type; oi.sizep = sizep; - if (sha1_object_info_extended(sha1, &oi) < 0) + if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0) return -1; return type; } @@ -2634,12 +2640,7 @@ int pretend_sha1_file(void *buf, unsigned long len, enum object_type type, hash_sha1_file(buf, len, typename(type), sha1); if (has_sha1_file(sha1) || find_cached_object(sha1)) return 0; - if (cached_object_alloc <= cached_object_nr) { - cached_object_alloc = alloc_nr(cached_object_alloc); - cached_objects = xrealloc(cached_objects, - sizeof(*cached_objects) * - cached_object_alloc); - } + ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc); co = &cached_objects[cached_object_nr++]; co->size = len; co->type = type; @@ -2687,10 +2688,8 @@ void *read_sha1_file_extended(const unsigned char *sha1, unsigned flag) { void *data; - char *path; const struct packed_git *p; - const unsigned char *repl = (flag & READ_SHA1_FILE_REPLACE) - ? lookup_replace_object(sha1) : sha1; + const unsigned char *repl = lookup_replace_object_extended(sha1, flag); errno = 0; data = read_object(repl, type, size); @@ -2706,7 +2705,8 @@ void *read_sha1_file_extended(const unsigned char *sha1, sha1_to_hex(repl), sha1_to_hex(sha1)); if (has_loose_object(repl)) { - path = sha1_file_name(sha1); + const char *path = sha1_file_name(sha1); + die("loose object %s (stored in %s) is corrupt", sha1_to_hex(repl), path); } @@ -2904,10 +2904,9 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, git_zstream stream; git_SHA_CTX c; unsigned char parano_sha1[20]; - char *filename; static char tmp_file[PATH_MAX]; + const char *filename = sha1_file_name(sha1); - filename = sha1_file_name(sha1); fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename); if (fd < 0) { if (errno == EACCES) |