diff options
Diffstat (limited to 'sha1_file.c')
| -rw-r--r-- | sha1_file.c | 276 |
1 files changed, 148 insertions, 128 deletions
diff --git a/sha1_file.c b/sha1_file.c index 36d55c05f7..019628add5 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -105,50 +105,63 @@ 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 (pos) { - pos = strchr(pos, '/'); - if (!pos) + 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; } @@ -805,15 +818,38 @@ 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 ;-) */ @@ -1440,51 +1476,6 @@ 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) { @@ -1512,14 +1503,6 @@ 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; @@ -1527,27 +1510,6 @@ 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); } @@ -1739,6 +1701,38 @@ 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, @@ -1896,6 +1890,22 @@ 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; @@ -2479,17 +2489,23 @@ 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. + * 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) { - if (oi->disk_sizep) { - struct stat st; - if (stat_sha1_file(sha1, &st) < 0) - return -1; + struct stat st; + if (stat_sha1_file(sha1, &st) < 0) + return -1; + if (oi->disk_sizep) *oi->disk_sizep = st.st_size; - } return 0; } @@ -2512,14 +2528,14 @@ static int sha1_loose_object_info(const unsigned char *sha1, 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 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; @@ -2527,27 +2543,29 @@ 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 { @@ -2561,6 +2579,7 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi) return 0; } +/* returns enum object_type or negative */ int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) { enum object_type type; @@ -2568,7 +2587,7 @@ 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; } @@ -2660,8 +2679,7 @@ void *read_sha1_file_extended(const unsigned char *sha1, 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); @@ -2855,7 +2873,9 @@ 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 */ |