diff options
Diffstat (limited to 'sha1_file.c')
| -rw-r--r-- | sha1_file.c | 257 |
1 files changed, 138 insertions, 119 deletions
diff --git a/sha1_file.c b/sha1_file.c index 064a330408..44444ae8f4 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -834,7 +834,7 @@ static int in_window(struct pack_window *win, off_t offset) unsigned char *use_pack(struct packed_git *p, struct pack_window **w_cursor, off_t offset, - unsigned int *left) + unsigned long *left) { struct pack_window *win = *w_cursor; @@ -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; @@ -1205,20 +1205,49 @@ static void *map_sha1_file(const unsigned char *sha1, unsigned long *size) return map; } -static int legacy_loose_object(unsigned char *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; /* - * 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 + * 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)) - return 1; - else + if ((map[0] & 0x8F) == 0x08 && !(word % 31)) return 0; + else + return 1; } unsigned long unpack_object_header_buffer(const unsigned char *buf, @@ -1245,7 +1274,7 @@ unsigned long unpack_object_header_buffer(const unsigned char *buf, return used; } -static int unpack_sha1_header(z_stream *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] = { @@ -1262,37 +1291,32 @@ static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned lon stream->next_out = buffer; stream->avail_out = bufsiz; - if (legacy_loose_object(map)) { - git_inflate_init(stream); - return git_inflate(stream, 0); - } - + 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; - /* - * 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 don't write it any longer. But 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); - /* Set up the stream for the rest.. */ - stream->next_in = map; - stream->avail_in = mapsize; + /* And generate the fake traditional header */ + stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu", + typename(type), size); + return 0; + } git_inflate_init(stream); - - /* And generate the fake traditional header */ - stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu", - typename(type), size); - return 0; + return git_inflate(stream, 0); } -static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1) +static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1) { int bytes = strlen(buffer) + 1; unsigned char *buf = xmallocz(size); @@ -1342,7 +1366,7 @@ static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size * 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; @@ -1391,7 +1415,7 @@ static int parse_sha1_header(const char *hdr, unsigned long *sizep) static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1) { int ret; - z_stream stream; + git_zstream stream; char hdr[8192]; ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)); @@ -1407,7 +1431,7 @@ unsigned long get_size_from_delta(struct packed_git *p, { const unsigned char *data; unsigned char delta_head[20], *in; - z_stream stream; + git_zstream stream; int st; memset(&stream, 0, sizeof(stream)); @@ -1481,7 +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, @@ -1495,7 +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; @@ -1523,13 +1547,13 @@ 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 int left; + unsigned long left; unsigned long used; enum object_type type; @@ -1549,63 +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; @@ -1613,6 +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: @@ -1642,7 +1613,7 @@ static void *unpack_compressed_entry(struct packed_git *p, unsigned long size) { int st; - z_stream stream; + git_zstream stream; unsigned char *buffer, *in; buffer = xmallocz(size); @@ -1695,6 +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) { @@ -1839,6 +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, @@ -1848,6 +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; @@ -2075,7 +2074,7 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size int status; unsigned long mapsize, size; void *map; - z_stream stream; + git_zstream stream; char hdr[32]; map = map_sha1_file(sha1, &mapsize); @@ -2093,24 +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(); @@ -2118,15 +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) { @@ -2424,7 +2443,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, { int fd, ret; unsigned char compressed[4096]; - z_stream stream; + git_zstream stream; git_SHA_CTX c; unsigned char parano_sha1[20]; char *filename; @@ -2441,7 +2460,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, /* Set it up */ memset(&stream, 0, sizeof(stream)); - deflateInit(&stream, zlib_compression_level); + git_deflate_init(&stream, zlib_compression_level); stream.next_out = compressed; stream.avail_out = sizeof(compressed); git_SHA1_Init(&c); @@ -2449,8 +2468,8 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, /* First header.. */ stream.next_in = (unsigned char *)hdr; stream.avail_in = hdrlen; - while (deflate(&stream, 0) == Z_OK) - /* nothing */; + while (git_deflate(&stream, 0) == Z_OK) + ; /* nothing */ git_SHA1_Update(&c, hdr, hdrlen); /* Then the data itself.. */ @@ -2458,7 +2477,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, stream.avail_in = len; do { unsigned char *in0 = stream.next_in; - ret = deflate(&stream, Z_FINISH); + ret = git_deflate(&stream, Z_FINISH); git_SHA1_Update(&c, in0, stream.next_in - in0); if (write_buffer(fd, compressed, stream.next_out - compressed) < 0) die("unable to write sha1 file"); @@ -2468,7 +2487,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, if (ret != Z_STREAM_END) die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret); - ret = deflateEnd(&stream); + ret = git_deflate_end_gently(&stream); if (ret != Z_OK) die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret); git_SHA1_Final(parano_sha1, &c); @@ -2704,7 +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) |