diff options
Diffstat (limited to 'sha1_file.c')
| -rw-r--r-- | sha1_file.c | 668 |
1 files changed, 429 insertions, 239 deletions
diff --git a/sha1_file.c b/sha1_file.c index 67e815b2db..34d527f670 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -36,6 +36,9 @@ static inline uintmax_t sz_fmt(size_t s) { return s; } const unsigned char null_sha1[20]; +static const char *no_log_pack_access = "no_log_pack_access"; +static const char *log_pack_access; + /* * This is meant to hold a *small* number of objects that you would * want read_sha1_file() to be able to return, but yet you do not want @@ -57,6 +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) @@ -102,50 +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 (pos) { - pos = strchr(pos, '/'); - if (!pos) + while (ret == SCLD_OK && next_component) { + struct stat st; + char *slash = next_component, slash_character; + + while (*slash && !is_dir_sep(*slash)) + slash++; + + 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; } @@ -162,17 +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; @@ -192,6 +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) { @@ -236,8 +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. * @@ -422,8 +437,7 @@ 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) @@ -475,7 +489,12 @@ 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; @@ -611,7 +630,7 @@ static void scan_windows(struct packed_git *p, } } -static int unuse_one_window(struct packed_git *current, int keep_fd) +static int unuse_one_window(struct packed_git *current) { struct packed_git *p, *lru_p = NULL; struct pack_window *lru_w = NULL, *lru_l = NULL; @@ -625,15 +644,8 @@ static int unuse_one_window(struct packed_git *current, int keep_fd) pack_mapped -= lru_w->len; if (lru_l) lru_l->next = lru_w->next; - else { + else lru_p->windows = lru_w->next; - if (!lru_p->windows && lru_p->pack_fd != -1 - && lru_p->pack_fd != keep_fd) { - close(lru_p->pack_fd); - pack_open_fds--; - lru_p->pack_fd = -1; - } - } free(lru_w); pack_open_windows--; return 1; @@ -641,10 +653,10 @@ static int unuse_one_window(struct packed_git *current, int keep_fd) return 0; } -void release_pack_memory(size_t need, int fd) +void release_pack_memory(size_t need) { size_t cur = pack_mapped; - while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd)) + while (need >= (cur - pack_mapped) && unuse_one_window(NULL)) ; /* nothing */ } @@ -655,7 +667,7 @@ void *xmmap(void *start, size_t length, if (ret == MAP_FAILED) { if (!length) return NULL; - release_pack_memory(length, fd); + release_pack_memory(length); ret = mmap(start, length, prot, flags, fd, offset); if (ret == MAP_FAILED) die_errno("Out of memory? mmap failed"); @@ -679,6 +691,83 @@ void close_pack_windows(struct packed_git *p) } } +/* + * The LRU pack is the one with the oldest MRU window, preferring packs + * with no used windows, or the oldest mtime if it has no windows allocated. + */ +static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse) +{ + struct pack_window *w, *this_mru_w; + int has_windows_inuse = 0; + + /* + * Reject this pack if it has windows and the previously selected + * one does not. If this pack does not have windows, reject + * it if the pack file is newer than the previously selected one. + */ + if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime)) + return; + + for (w = this_mru_w = p->windows; w; w = w->next) { + /* + * Reject this pack if any of its windows are in use, + * but the previously selected pack did not have any + * inuse windows. Otherwise, record that this pack + * has windows in use. + */ + if (w->inuse_cnt) { + if (*accept_windows_inuse) + has_windows_inuse = 1; + else + return; + } + + if (w->last_used > this_mru_w->last_used) + this_mru_w = w; + + /* + * Reject this pack if it has windows that have been + * used more recently than the previously selected pack. + * If the previously selected pack had windows inuse and + * we have not encountered a window in this pack that is + * inuse, skip this check since we prefer a pack with no + * inuse windows to one that has inuse windows. + */ + if (*mru_w && *accept_windows_inuse == has_windows_inuse && + this_mru_w->last_used > (*mru_w)->last_used) + return; + } + + /* + * Select this pack. + */ + *mru_w = this_mru_w; + *lru_p = p; + *accept_windows_inuse = has_windows_inuse; +} + +static int close_one_pack(void) +{ + struct packed_git *p, *lru_p = NULL; + struct pack_window *mru_w = NULL; + int accept_windows_inuse = 1; + + for (p = packed_git; p; p = p->next) { + if (p->pack_fd == -1) + continue; + find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse); + } + + if (lru_p) { + close(lru_p->pack_fd); + pack_open_fds--; + lru_p->pack_fd = -1; + return 1; + } + + return 0; +} + void unuse_pack(struct pack_window **w_cursor) { struct pack_window *w = *w_cursor; @@ -701,7 +790,7 @@ 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(). @@ -734,15 +823,38 @@ void free_pack_by_name(const char *pack_name) static unsigned int get_max_fd_limit(void) { #ifdef RLIMIT_NOFILE - struct rlimit lim; + { + struct rlimit lim; - if (getrlimit(RLIMIT_NOFILE, &lim)) - die_errno("cannot get RLIMIT_NOFILE"); + if (!getrlimit(RLIMIT_NOFILE, &lim)) + return lim.rlim_cur; + } +#endif + +#ifdef _SC_OPEN_MAX + { + long open_max = sysconf(_SC_OPEN_MAX); + if (0 < open_max) + return open_max; + /* + * Otherwise, we got -1 for one of the two + * reasons: + * + * (1) sysconf() did not understand _SC_OPEN_MAX + * and signaled an error with -1; or + * (2) sysconf() said there is no limit. + * + * We _could_ clear errno before calling sysconf() to + * tell these two cases apart and return a huge number + * in the latter case to let the caller cap it to a + * value that is not so selfish, but letting the + * fallback OPEN_MAX codepath take care of these cases + * is a lot simpler. + */ + } +#endif - return lim.rlim_cur; -#elif defined(_SC_OPEN_MAX) - return sysconf(_SC_OPEN_MAX); -#elif defined(OPEN_MAX) +#ifdef OPEN_MAX return OPEN_MAX; #else return 1; /* see the caller ;-) */ @@ -774,7 +886,7 @@ static int open_packed_git_1(struct packed_git *p) pack_max_fds = 1; } - while (pack_max_fds <= pack_open_fds && unuse_one_window(NULL, -1)) + while (pack_max_fds <= pack_open_fds && close_one_pack()) ; /* nothing */ p->pack_fd = git_open_noatime(p->pack_name); @@ -890,7 +1002,7 @@ unsigned char *use_pack(struct packed_git *p, win->len = (size_t)len; pack_mapped += win->len; while (packed_git_limit < pack_mapped - && unuse_one_window(p, p->pack_fd)) + && unuse_one_window(p)) ; /* nothing */ win->base = xmmap(NULL, win->len, PROT_READ, MAP_PRIVATE, @@ -936,7 +1048,7 @@ static struct packed_git *alloc_packed_git(int extra) static void try_to_free_pack_memory(size_t size) { - release_pack_memory(size, -1); + release_pack_memory(size); } struct packed_git *add_packed_git(const char *path, int path_len, int local) @@ -1014,7 +1126,7 @@ 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"; @@ -1123,6 +1235,7 @@ 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 @@ -1207,7 +1320,6 @@ void prepare_packed_git(void) void reprepare_packed_git(void) { - discard_revindex(); prepare_packed_git_run_once = 0; prepare_packed_git(); } @@ -1284,7 +1396,7 @@ 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; @@ -1303,25 +1415,45 @@ static int git_open_noatime(const char *name) } } +static int stat_sha1_file(const unsigned char *sha1, struct stat *st) +{ + struct alternate_object_database *alt; + + if (!lstat(sha1_file_name(sha1), st)) + return 0; + + prepare_alt_odb(); + errno = ENOENT; + for (alt = alt_odb_list; alt; alt = alt->next) { + fill_sha1_path(alt->name, sha1); + if (!lstat(alt->base, st)) + return 0; + } + + return -1; +} + 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; } @@ -1349,51 +1481,6 @@ 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) { @@ -1421,14 +1508,6 @@ 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; @@ -1436,27 +1515,6 @@ 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); } @@ -1648,6 +1706,38 @@ 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, @@ -1690,46 +1780,21 @@ static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset) return type; } - #define POI_STACK_PREALLOC 64 -static int packed_object_info(struct packed_git *p, off_t obj_offset, - unsigned long *sizep, int *rtype) +static enum object_type packed_to_object_type(struct packed_git *p, + off_t obj_offset, + enum object_type type, + struct pack_window **w_curs, + off_t curpos) { - struct pack_window *w_curs = NULL; - unsigned long size; - off_t curpos = obj_offset; - enum object_type type; off_t small_poi_stack[POI_STACK_PREALLOC]; off_t *poi_stack = small_poi_stack; int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC; - type = unpack_object_header(p, &w_curs, &curpos, &size); - - if (rtype) - *rtype = type; /* representation type */ - - if (sizep) { - if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) { - off_t tmp_pos = curpos; - off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos, - type, obj_offset); - if (!base_offset) { - type = OBJ_BAD; - goto out; - } - *sizep = get_size_from_delta(p, &w_curs, tmp_pos); - if (*sizep == 0) { - type = OBJ_BAD; - goto out; - } - } else { - *sizep = size; - } - } - while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) { off_t base_offset; + unsigned long size; /* Push the object we're going to leave behind */ if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) { poi_stack_alloc = alloc_nr(poi_stack_nr); @@ -1740,11 +1805,11 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset, } poi_stack[poi_stack_nr++] = obj_offset; /* If parsing the base offset fails, just unwind */ - base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset); + base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset); if (!base_offset) goto unwind; curpos = obj_offset = base_offset; - type = unpack_object_header(p, &w_curs, &curpos, &size); + type = unpack_object_header(p, w_curs, &curpos, &size); if (type <= OBJ_NONE) { /* If getting the base itself fails, we first * retry the base, otherwise unwind */ @@ -1771,7 +1836,6 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset, out: if (poi_stack != small_poi_stack) free(poi_stack); - unuse_pack(&w_curs); return type; unwind: @@ -1785,6 +1849,73 @@ unwind: goto out; } +static int packed_object_info(struct packed_git *p, off_t obj_offset, + struct object_info *oi) +{ + struct pack_window *w_curs = NULL; + unsigned long size; + off_t curpos = obj_offset; + enum object_type type; + + /* + * We always get the representation type, but only convert it to + * a "real" type later if the caller is interested. + */ + type = unpack_object_header(p, &w_curs, &curpos, &size); + + if (oi->sizep) { + if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) { + off_t tmp_pos = curpos; + off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos, + type, obj_offset); + if (!base_offset) { + type = OBJ_BAD; + goto out; + } + *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos); + if (*oi->sizep == 0) { + type = OBJ_BAD; + goto out; + } + } else { + *oi->sizep = size; + } + } + + if (oi->disk_sizep) { + struct revindex_entry *revidx = find_pack_revindex(p, obj_offset); + *oi->disk_sizep = revidx[1].offset - obj_offset; + } + + if (oi->typep) { + *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos); + if (*oi->typep < 0) { + type = OBJ_BAD; + goto out; + } + } + + 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; +} + static void *unpack_compressed_entry(struct packed_git *p, struct pack_window **w_curs, off_t curpos, @@ -1956,12 +2087,19 @@ static void write_pack_access_log(struct packed_git *p, off_t obj_offset) { static FILE *log_file; + if (!log_pack_access) + log_pack_access = getenv("GIT_TRACE_PACK_ACCESS"); + if (!log_pack_access) + log_pack_access = no_log_pack_access; + if (log_pack_access == no_log_pack_access) + return; + if (!log_file) { log_file = fopen(log_pack_access, "w"); if (!log_file) { error("cannot open pack access log '%s' for writing: %s", log_pack_access, strerror(errno)); - log_pack_access = NULL; + log_pack_access = no_log_pack_access; return; } } @@ -1992,7 +2130,7 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset, int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC; int base_from_cache = 0; - if (log_pack_access) + if (log_pack_access != no_log_pack_access) write_pack_access_log(p, obj_offset); /* PHASE 1: drill down to the innermost base object */ @@ -2001,6 +2139,16 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset, int i; struct delta_base_cache_entry *ent; + ent = get_delta_base_cache_entry(p, curpos); + if (eq_delta_base_cache_entry(ent, p, curpos)) { + type = ent->type; + data = ent->data; + size = ent->size; + clear_delta_base_cache_entry(ent); + base_from_cache = 1; + break; + } + if (do_check_packed_object_crc && p->index_version > 1) { struct revindex_entry *revidx = find_pack_revindex(p, obj_offset); unsigned long len = revidx[1].offset - obj_offset; @@ -2015,16 +2163,6 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset, } } - ent = get_delta_base_cache_entry(p, curpos); - if (eq_delta_base_cache_entry(ent, p, curpos)) { - type = ent->type; - data = ent->data; - size = ent->size; - clear_delta_base_cache_entry(ent); - base_from_cache = 1; - break; - } - type = unpack_object_header(p, &w_curs, &curpos, &size); if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA) break; @@ -2135,16 +2273,29 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset, data = patch_delta(base, base_size, delta_data, delta_size, &size); + + /* + * We could not apply the delta; warn the user, but keep going. + * Our failure will be noticed either in the next iteration of + * the loop, or if this is the final delta, in the caller when + * we return NULL. Those code paths will take care of making + * a more explicit warning and retrying with another copy of + * the object. + */ if (!data) - die("failed to apply delta"); + error("failed to apply delta"); - free (delta_data); + free(delta_data); } *final_type = type; *final_size = size; unuse_pack(&w_curs); + + if (delta_stack != small_delta_stack) + free(delta_stack); + return data; } @@ -2304,6 +2455,10 @@ 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; @@ -2316,11 +2471,13 @@ 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; } @@ -2338,7 +2495,8 @@ struct packed_git *find_sha1_pack(const unsigned char *sha1, } -static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep) +static int sha1_loose_object_info(const unsigned char *sha1, + struct object_info *oi) { int status; unsigned long mapsize, size; @@ -2346,54 +2504,83 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size 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 + * do not optimize out the stat call, even if the + * caller doesn't care about the disk-size, since our + * return value implicitly indicates whether the + * object even exists. + */ + if (!oi->typep && !oi->sizep) { + struct stat st; + if (stat_sha1_file(sha1, &st) < 0) + return -1; + if (oi->disk_sizep) + *oi->disk_sizep = st.st_size; + return 0; + } + map = map_sha1_file(sha1, &mapsize); if (!map) - return error("unable to find %s", sha1_to_hex(sha1)); + return -1; + if (oi->disk_sizep) + *oi->disk_sizep = mapsize; if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) status = error("unable to unpack %s header", sha1_to_hex(sha1)); else if ((status = parse_sha1_header(hdr, &size)) < 0) status = error("unable to parse %s header", sha1_to_hex(sha1)); - else if (sizep) - *sizep = size; + else if (oi->sizep) + *oi->sizep = size; git_inflate_end(&stream); munmap(map, mapsize); - return status; + if (oi->typep) + *oi->typep = status; + return 0; } -/* returns enum object_type or negative */ -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 status, rtype; + 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; if (oi->sizep) *(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 co->type; + return 0; } - if (!find_pack_entry(sha1, &e)) { + if (!find_pack_entry(real, &e)) { /* Most likely it's a loose object. */ - status = sha1_loose_object_info(sha1, oi->sizep); - if (status >= 0) { + if (!sha1_loose_object_info(real, oi)) { oi->whence = OI_LOOSE; - return status; + return 0; } /* Not a loose object; someone else may have just packed it. */ reprepare_packed_git(); - if (!find_pack_entry(sha1, &e)) - return status; + if (!find_pack_entry(real, &e)) + return -1; } - status = packed_object_info(e.p, e.offset, oi->sizep, &rtype); - if (status < 0) { - mark_bad_packed_object(e.p, sha1); - status = sha1_object_info_extended(sha1, oi); + rtype = packed_object_info(e.p, e.offset, oi); + if (rtype < 0) { + 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 { @@ -2404,15 +2591,20 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi) rtype == OBJ_OFS_DELTA); } - return status; + return 0; } +/* returns enum object_type or negative */ int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) { - struct object_info oi; + enum object_type type; + struct object_info oi = {NULL}; + oi.typep = &type; oi.sizep = sizep; - return sha1_object_info_extended(sha1, &oi); + if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0) + return -1; + return type; } static void *read_packed_sha1(const unsigned char *sha1, @@ -2447,12 +2639,7 @@ 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; @@ -2500,10 +2687,8 @@ 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); @@ -2519,7 +2704,8 @@ 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); } @@ -2697,7 +2883,9 @@ static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename) /* Make sure the directory exists */ memcpy(buffer, filename, dirlen); buffer[dirlen-1] = 0; - if (mkdir(buffer, 0777) || adjust_shared_perm(buffer)) + if (mkdir(buffer, 0777) && errno != EEXIST) + return -1; + if (adjust_shared_perm(buffer)) return -1; /* Try again */ @@ -2715,10 +2903,9 @@ 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) @@ -2835,7 +3022,10 @@ int has_sha1_file(const unsigned char *sha1) if (find_pack_entry(sha1, &e)) return 1; - return has_loose_object(sha1); + if (has_loose_object(sha1)) + return 1; + reprepare_packed_git(); + return find_pack_entry(sha1, &e); } static void check_tree(const void *buf, size_t size) |