diff options
Diffstat (limited to 'sha1_file.c')
| -rw-r--r-- | sha1_file.c | 177 |
1 files changed, 96 insertions, 81 deletions
diff --git a/sha1_file.c b/sha1_file.c index 92e87ee225..e002056b85 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -380,7 +380,7 @@ void add_to_alternates_file(const char *reference) { struct lock_file *lock = xcalloc(1, sizeof(struct lock_file)); int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR); - char *alt = mkpath("%s/objects\n", reference); + char *alt = mkpath("%s\n", reference); write_or_die(fd, alt, strlen(alt)); if (commit_lock_file(lock)) die("could not close alternates file"); @@ -1186,7 +1186,7 @@ static int open_sha1_file(const unsigned char *sha1) return -1; } -static void *map_sha1_file(const unsigned char *sha1, unsigned long *size) +void *map_sha1_file(const unsigned char *sha1, unsigned long *size) { void *map; int fd; @@ -1217,14 +1217,34 @@ static int experimental_loose_object(unsigned char *map) unsigned int word; /* - * Is it a zlib-compressed buffer? If so, the first byte - * must be 0x78 (15-bit window size, deflated), and the - * first 16-bit word is evenly divisible by 31. If so, - * we are looking at the official format, not the experimental - * one. + * 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] == 0x78 && !(word % 31)) + if ((map[0] & 0x8F) == 0x08 && !(word % 31)) return 0; else return 1; @@ -1254,7 +1274,7 @@ unsigned long unpack_object_header_buffer(const unsigned char *buf, return used; } -static int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz) +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] = { @@ -1346,7 +1366,7 @@ static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long s * too permissive for what we want to check. So do an anal * object header parse by hand. */ -static int parse_sha1_header(const char *hdr, unsigned long *sizep) +int parse_sha1_header(const char *hdr, unsigned long *sizep) { char type[10]; int i; @@ -1485,7 +1505,7 @@ static off_t get_delta_base(struct packed_git *p, /* forward declaration for a mutually recursive function */ static int packed_object_info(struct packed_git *p, off_t offset, - unsigned long *sizep); + unsigned long *sizep, int *rtype); static int packed_delta_info(struct packed_git *p, struct pack_window **w_curs, @@ -1499,7 +1519,7 @@ static int packed_delta_info(struct packed_git *p, base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset); if (!base_offset) return OBJ_BAD; - type = packed_object_info(p, base_offset, NULL); + type = packed_object_info(p, base_offset, NULL, NULL); if (type <= OBJ_NONE) { struct revindex_entry *revidx; const unsigned char *base_sha1; @@ -1527,10 +1547,10 @@ static int packed_delta_info(struct packed_git *p, return type; } -static int unpack_object_header(struct packed_git *p, - struct pack_window **w_curs, - off_t *curpos, - unsigned long *sizep) +int unpack_object_header(struct packed_git *p, + struct pack_window **w_curs, + off_t *curpos, + unsigned long *sizep) { unsigned char *base; unsigned long left; @@ -1553,63 +1573,8 @@ static int unpack_object_header(struct packed_git *p, return type; } -const char *packed_object_info_detail(struct packed_git *p, - off_t obj_offset, - unsigned long *size, - unsigned long *store_size, - unsigned int *delta_chain_length, - unsigned char *base_sha1) -{ - struct pack_window *w_curs = NULL; - off_t curpos; - unsigned long dummy; - unsigned char *next_sha1; - enum object_type type; - struct revindex_entry *revidx; - - *delta_chain_length = 0; - curpos = obj_offset; - type = unpack_object_header(p, &w_curs, &curpos, size); - - revidx = find_pack_revindex(p, obj_offset); - *store_size = revidx[1].offset - obj_offset; - - for (;;) { - switch (type) { - default: - die("pack %s contains unknown object type %d", - p->pack_name, type); - case OBJ_COMMIT: - case OBJ_TREE: - case OBJ_BLOB: - case OBJ_TAG: - unuse_pack(&w_curs); - return typename(type); - case OBJ_OFS_DELTA: - obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset); - if (!obj_offset) - die("pack %s contains bad delta base reference of type %s", - p->pack_name, typename(type)); - if (*delta_chain_length == 0) { - revidx = find_pack_revindex(p, obj_offset); - hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr)); - } - break; - case OBJ_REF_DELTA: - next_sha1 = use_pack(p, &w_curs, curpos, NULL); - if (*delta_chain_length == 0) - hashcpy(base_sha1, next_sha1); - obj_offset = find_pack_entry_one(next_sha1, p); - break; - } - (*delta_chain_length)++; - curpos = obj_offset; - type = unpack_object_header(p, &w_curs, &curpos, &dummy); - } -} - static int packed_object_info(struct packed_git *p, off_t obj_offset, - unsigned long *sizep) + unsigned long *sizep, int *rtype) { struct pack_window *w_curs = NULL; unsigned long size; @@ -1617,6 +1582,8 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset, enum object_type type; type = unpack_object_header(p, &w_curs, &curpos, &size); + if (rtype) + *rtype = type; /* representation type */ switch (type) { case OBJ_OFS_DELTA: @@ -1699,6 +1666,13 @@ static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset) return hash % MAX_DELTA_CACHE; } +static int in_delta_base_cache(struct packed_git *p, off_t base_offset) +{ + unsigned long hash = pack_entry_hash(p, base_offset); + struct delta_base_cache_entry *ent = delta_base_cache + hash; + return (ent->data && ent->p == p && ent->base_offset == base_offset); +} + static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset, unsigned long *base_size, enum object_type *type, int keep_cache) { @@ -1843,6 +1817,24 @@ static void *unpack_delta_entry(struct packed_git *p, return result; } +static void write_pack_access_log(struct packed_git *p, off_t obj_offset) +{ + static FILE *log_file; + + 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; + return; + } + } + fprintf(log_file, "%s %"PRIuMAX"\n", + p->pack_name, (uintmax_t)obj_offset); + fflush(log_file); +} + int do_check_packed_object_crc; void *unpack_entry(struct packed_git *p, off_t obj_offset, @@ -1852,6 +1844,9 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset, off_t curpos = obj_offset; void *data; + if (log_pack_access) + write_pack_access_log(p, obj_offset); + 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; @@ -2097,24 +2092,28 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size return status; } -int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) +/* returns enum object_type or negative */ +int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi) { struct cached_object *co; struct pack_entry e; - int status; + int status, rtype; co = find_cached_object(sha1); if (co) { - if (sizep) - *sizep = co->size; + if (oi->sizep) + *(oi->sizep) = co->size; + oi->whence = OI_CACHED; return co->type; } if (!find_pack_entry(sha1, &e)) { /* Most likely it's a loose object. */ - status = sha1_loose_object_info(sha1, sizep); - if (status >= 0) + status = sha1_loose_object_info(sha1, oi->sizep); + if (status >= 0) { + oi->whence = OI_LOOSE; return status; + } /* Not a loose object; someone else may have just packed it. */ reprepare_packed_git(); @@ -2122,15 +2121,31 @@ int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) return status; } - status = packed_object_info(e.p, e.offset, sizep); + 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(sha1, sizep); + status = sha1_object_info_extended(sha1, oi); + } else if (in_delta_base_cache(e.p, e.offset)) { + oi->whence = OI_DBCACHED; + } else { + oi->whence = OI_PACKED; + oi->u.packed.offset = e.offset; + oi->u.packed.pack = e.p; + oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA || + rtype == OBJ_OFS_DELTA); } return status; } +int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) +{ + struct object_info oi; + + oi.sizep = sizep; + return sha1_object_info_extended(sha1, &oi); +} + static void *read_packed_sha1(const unsigned char *sha1, enum object_type *type, unsigned long *size) { @@ -2708,7 +2723,7 @@ static int index_stream(unsigned char *sha1, int fd, size_t size, while (size) { char buf[10240]; size_t sz = size < sizeof(buf) ? size : sizeof(buf); - size_t actual; + ssize_t actual; actual = read_in_full(fd, buf, sz); if (actual < 0) |