object.c

   1 #include "cache.h"
   2 #include "object.h"
   3 #include "replace-object.h"
   4 #include "object-store.h"
   5 #include "blob.h"
   6 #include "tree.h"
   7 #include "commit.h"
   8 #include "tag.h"
   9 #include "alloc.h"
  10 #include "packfile.h"
  11 #include "commit-graph.h"
  12
  13 unsigned int get_max_object_index(void)
  14 {
  15         return the_repository->parsed_objects->obj_hash_size;
  16 }
  17
  18 struct object *get_indexed_object(unsigned int idx)
  19 {
  20         return the_repository->parsed_objects->obj_hash[idx];
  21 }
  22
  23 static const char *object_type_strings[] = {
  24         NULL,           /* OBJ_NONE = 0 */
  25         "commit",       /* OBJ_COMMIT = 1 */
  26         "tree",         /* OBJ_TREE = 2 */
  27         "blob",         /* OBJ_BLOB = 3 */
  28         "tag",          /* OBJ_TAG = 4 */
  29 };
  30
  31 const char *type_name(unsigned int type)
  32 {
  33         if (type >= ARRAY_SIZE(object_type_strings))
  34                 return NULL;
  35         return object_type_strings[type];
  36 }
  37
  38 int type_from_string_gently(const char *str, ssize_t len, int gentle)
  39 {
  40         int i;
  41
  42         if (len < 0)
  43                 len = strlen(str);
  44
  45         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  46                 if (!strncmp(str, object_type_strings[i], len) &&
  47                     object_type_strings[i][len] == '\0')
  48                         return i;
  49
  50         if (gentle)
  51                 return -1;
  52
  53         die(_("invalid object type \"%s\""), str);
  54 }
  55
  56 /*
  57  * Return a numerical hash value between 0 and n-1 for the object with
  58  * the specified sha1.  n must be a power of 2.  Please note that the
  59  * return value is *not* consistent across computer architectures.
  60  */
  61 static unsigned int hash_obj(const struct object_id *oid, unsigned int n)
  62 {
  63         return oidhash(oid) & (n - 1);
  64 }
  65
  66 /*
  67  * Insert obj into the hash table hash, which has length size (which
  68  * must be a power of 2).  On collisions, simply overflow to the next
  69  * empty bucket.
  70  */
  71 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  72 {
  73         unsigned int j = hash_obj(&obj->oid, size);
  74
  75         while (hash[j]) {
  76                 j++;
  77                 if (j >= size)
  78                         j = 0;
  79         }
  80         hash[j] = obj;
  81 }
  82
  83 /*
  84  * Look up the record for the given sha1 in the hash map stored in
  85  * obj_hash.  Return NULL if it was not found.
  86  */
  87 struct object *lookup_object(struct repository *r, const struct object_id *oid)
  88 {
  89         unsigned int i, first;
  90         struct object *obj;
  91
  92         if (!r->parsed_objects->obj_hash)
  93                 return NULL;
  94
  95         first = i = hash_obj(oid, r->parsed_objects->obj_hash_size);
  96         while ((obj = r->parsed_objects->obj_hash[i]) != NULL) {
  97                 if (oideq(oid, &obj->oid))
  98                         break;
  99                 i++;
 100                 if (i == r->parsed_objects->obj_hash_size)
 101                         i = 0;
 102         }
 103         if (obj && i != first) {
 104                 /*
 105                  * Move object to where we started to look for it so
 106                  * that we do not need to walk the hash table the next
 107                  * time we look for it.
 108                  */
 109                 SWAP(r->parsed_objects->obj_hash[i],
 110                      r->parsed_objects->obj_hash[first]);
 111         }
 112         return obj;
 113 }
 114
 115 /*
 116  * Increase the size of the hash map stored in obj_hash to the next
 117  * power of 2 (but at least 32).  Copy the existing values to the new
 118  * hash map.
 119  */
 120 static void grow_object_hash(struct repository *r)
 121 {
 122         int i;
 123         /*
 124          * Note that this size must always be power-of-2 to match hash_obj
 125          * above.
 126          */
 127         int new_hash_size = r->parsed_objects->obj_hash_size < 32 ? 32 : 2 * r->parsed_objects->obj_hash_size;
 128         struct object **new_hash;
 129
 130         CALLOC_ARRAY(new_hash, new_hash_size);
 131         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 132                 struct object *obj = r->parsed_objects->obj_hash[i];
 133
 134                 if (!obj)
 135                         continue;
 136                 insert_obj_hash(obj, new_hash, new_hash_size);
 137         }
 138         free(r->parsed_objects->obj_hash);
 139         r->parsed_objects->obj_hash = new_hash;
 140         r->parsed_objects->obj_hash_size = new_hash_size;
 141 }
 142
 143 void *create_object(struct repository *r, const struct object_id *oid, void *o)
 144 {
 145         struct object *obj = o;
 146
 147         obj->parsed = 0;
 148         obj->flags = 0;
 149         oidcpy(&obj->oid, oid);
 150
 151         if (r->parsed_objects->obj_hash_size - 1 <= r->parsed_objects->nr_objs * 2)
 152                 grow_object_hash(r);
 153
 154         insert_obj_hash(obj, r->parsed_objects->obj_hash,
 155                         r->parsed_objects->obj_hash_size);
 156         r->parsed_objects->nr_objs++;
 157         return obj;
 158 }
 159
 160 void *object_as_type(struct object *obj, enum object_type type, int quiet)
 161 {
 162         if (obj->type == type)
 163                 return obj;
 164         else if (obj->type == OBJ_NONE) {
 165                 if (type == OBJ_COMMIT)
 166                         init_commit_node((struct commit *) obj);
 167                 else
 168                         obj->type = type;
 169                 return obj;
 170         }
 171         else {
 172                 if (!quiet)
 173                         error(_("object %s is a %s, not a %s"),
 174                               oid_to_hex(&obj->oid),
 175                               type_name(obj->type), type_name(type));
 176                 return NULL;
 177         }
 178 }
 179
 180 struct object *lookup_unknown_object(struct repository *r, const struct object_id *oid)
 181 {
 182         struct object *obj = lookup_object(r, oid);
 183         if (!obj)
 184                 obj = create_object(r, oid, alloc_object_node(r));
 185         return obj;
 186 }
 187
 188 struct object *lookup_object_by_type(struct repository *r,
 189                             const struct object_id *oid,
 190                             enum object_type type)
 191 {
 192         switch (type) {
 193         case OBJ_COMMIT:
 194                 return (struct object *)lookup_commit(r, oid);
 195         case OBJ_TREE:
 196                 return (struct object *)lookup_tree(r, oid);
 197         case OBJ_TAG:
 198                 return (struct object *)lookup_tag(r, oid);
 199         case OBJ_BLOB:
 200                 return (struct object *)lookup_blob(r, oid);
 201         default:
 202                 BUG("unknown object type %d", type);
 203         }
 204 }
 205
 206 struct object *parse_object_buffer(struct repository *r, const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
 207 {
 208         struct object *obj;
 209         *eaten_p = 0;
 210
 211         obj = NULL;
 212         if (type == OBJ_BLOB) {
 213                 struct blob *blob = lookup_blob(r, oid);
 214                 if (blob) {
 215                         if (parse_blob_buffer(blob, buffer, size))
 216                                 return NULL;
 217                         obj = &blob->object;
 218                 }
 219         } else if (type == OBJ_TREE) {
 220                 struct tree *tree = lookup_tree(r, oid);
 221                 if (tree) {
 222                         obj = &tree->object;
 223                         if (!tree->buffer)
 224                                 tree->object.parsed = 0;
 225                         if (!tree->object.parsed) {
 226                                 if (parse_tree_buffer(tree, buffer, size))
 227                                         return NULL;
 228                                 *eaten_p = 1;
 229                         }
 230                 }
 231         } else if (type == OBJ_COMMIT) {
 232                 struct commit *commit = lookup_commit(r, oid);
 233                 if (commit) {
 234                         if (parse_commit_buffer(r, commit, buffer, size, 1))
 235                                 return NULL;
 236                         if (!get_cached_commit_buffer(r, commit, NULL)) {
 237                                 set_commit_buffer(r, commit, buffer, size);
 238                                 *eaten_p = 1;
 239                         }
 240                         obj = &commit->object;
 241                 }
 242         } else if (type == OBJ_TAG) {
 243                 struct tag *tag = lookup_tag(r, oid);
 244                 if (tag) {
 245                         if (parse_tag_buffer(r, tag, buffer, size))
 246                                return NULL;
 247                         obj = &tag->object;
 248                 }
 249         } else {
 250                 warning(_("object %s has unknown type id %d"), oid_to_hex(oid), type);
 251                 obj = NULL;
 252         }
 253         return obj;
 254 }
 255
 256 struct object *parse_object_or_die(const struct object_id *oid,
 257                                    const char *name)
 258 {
 259         struct object *o = parse_object(the_repository, oid);
 260         if (o)
 261                 return o;
 262
 263         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
 264 }
 265
 266 struct object *parse_object_with_flags(struct repository *r,
 267                                        const struct object_id *oid,
 268                                        enum parse_object_flags flags)
 269 {
 270         int skip_hash = !!(flags & PARSE_OBJECT_SKIP_HASH_CHECK);
 271         unsigned long size;
 272         enum object_type type;
 273         int eaten;
 274         const struct object_id *repl = lookup_replace_object(r, oid);
 275         void *buffer;
 276         struct object *obj;
 277
 278         obj = lookup_object(r, oid);
 279         if (obj && obj->parsed)
 280                 return obj;
 281
 282         if (skip_hash) {
 283                 struct commit *commit = lookup_commit_in_graph(r, repl);
 284                 if (commit)
 285                         return &commit->object;
 286         }
 287
 288         if ((obj && obj->type == OBJ_BLOB && repo_has_object_file(r, oid)) ||
 289             (!obj && repo_has_object_file(r, oid) &&
 290              oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
 291                 if (!skip_hash && stream_object_signature(r, repl) < 0) {
 292                         error(_("hash mismatch %s"), oid_to_hex(oid));
 293                         return NULL;
 294                 }
 295                 parse_blob_buffer(lookup_blob(r, oid), NULL, 0);
 296                 return lookup_object(r, oid);
 297         }
 298
 299         buffer = repo_read_object_file(r, oid, &type, &size);
 300         if (buffer) {
 301                 if (!skip_hash &&
 302                     check_object_signature(r, repl, buffer, size, type) < 0) {
 303                         free(buffer);
 304                         error(_("hash mismatch %s"), oid_to_hex(repl));
 305                         return NULL;
 306                 }
 307
 308                 obj = parse_object_buffer(r, oid, type, size,
 309                                           buffer, &eaten);
 310                 if (!eaten)
 311                         free(buffer);
 312                 return obj;
 313         }
 314         return NULL;
 315 }
 316
 317 struct object *parse_object(struct repository *r, const struct object_id *oid)
 318 {
 319         return parse_object_with_flags(r, oid, 0);
 320 }
 321
 322 struct object_list *object_list_insert(struct object *item,
 323                                        struct object_list **list_p)
 324 {
 325         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 326         new_list->item = item;
 327         new_list->next = *list_p;
 328         *list_p = new_list;
 329         return new_list;
 330 }
 331
 332 int object_list_contains(struct object_list *list, struct object *obj)
 333 {
 334         while (list) {
 335                 if (list->item == obj)
 336                         return 1;
 337                 list = list->next;
 338         }
 339         return 0;
 340 }
 341
 342 void object_list_free(struct object_list **list)
 343 {
 344         while (*list) {
 345                 struct object_list *p = *list;
 346                 *list = p->next;
 347                 free(p);
 348         }
 349 }
 350
 351 /*
 352  * A zero-length string to which object_array_entry::name can be
 353  * initialized without requiring a malloc/free.
 354  */
 355 static char object_array_slopbuf[1];
 356
 357 void add_object_array_with_path(struct object *obj, const char *name,
 358                                 struct object_array *array,
 359                                 unsigned mode, const char *path)
 360 {
 361         unsigned nr = array->nr;
 362         unsigned alloc = array->alloc;
 363         struct object_array_entry *objects = array->objects;
 364         struct object_array_entry *entry;
 365
 366         if (nr >= alloc) {
 367                 alloc = (alloc + 32) * 2;
 368                 REALLOC_ARRAY(objects, alloc);
 369                 array->alloc = alloc;
 370                 array->objects = objects;
 371         }
 372         entry = &objects[nr];
 373         entry->item = obj;
 374         if (!name)
 375                 entry->name = NULL;
 376         else if (!*name)
 377                 /* Use our own empty string instead of allocating one: */
 378                 entry->name = object_array_slopbuf;
 379         else
 380                 entry->name = xstrdup(name);
 381         entry->mode = mode;
 382         if (path)
 383                 entry->path = xstrdup(path);
 384         else
 385                 entry->path = NULL;
 386         array->nr = ++nr;
 387 }
 388
 389 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 390 {
 391         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 392 }
 393
 394 /*
 395  * Free all memory associated with an entry; the result is
 396  * in an unspecified state and should not be examined.
 397  */
 398 static void object_array_release_entry(struct object_array_entry *ent)
 399 {
 400         if (ent->name != object_array_slopbuf)
 401                 free(ent->name);
 402         free(ent->path);
 403 }
 404
 405 struct object *object_array_pop(struct object_array *array)
 406 {
 407         struct object *ret;
 408
 409         if (!array->nr)
 410                 return NULL;
 411
 412         ret = array->objects[array->nr - 1].item;
 413         object_array_release_entry(&array->objects[array->nr - 1]);
 414         array->nr--;
 415         return ret;
 416 }
 417
 418 void object_array_filter(struct object_array *array,
 419                          object_array_each_func_t want, void *cb_data)
 420 {
 421         unsigned nr = array->nr, src, dst;
 422         struct object_array_entry *objects = array->objects;
 423
 424         for (src = dst = 0; src < nr; src++) {
 425                 if (want(&objects[src], cb_data)) {
 426                         if (src != dst)
 427                                 objects[dst] = objects[src];
 428                         dst++;
 429                 } else {
 430                         object_array_release_entry(&objects[src]);
 431                 }
 432         }
 433         array->nr = dst;
 434 }
 435
 436 void object_array_clear(struct object_array *array)
 437 {
 438         int i;
 439         for (i = 0; i < array->nr; i++)
 440                 object_array_release_entry(&array->objects[i]);
 441         FREE_AND_NULL(array->objects);
 442         array->nr = array->alloc = 0;
 443 }
 444
 445 /*
 446  * Return true if array already contains an entry.
 447  */
 448 static int contains_object(struct object_array *array,
 449                            const struct object *item, const char *name)
 450 {
 451         unsigned nr = array->nr, i;
 452         struct object_array_entry *object = array->objects;
 453
 454         for (i = 0; i < nr; i++, object++)
 455                 if (item == object->item && !strcmp(object->name, name))
 456                         return 1;
 457         return 0;
 458 }
 459
 460 void object_array_remove_duplicates(struct object_array *array)
 461 {
 462         unsigned nr = array->nr, src;
 463         struct object_array_entry *objects = array->objects;
 464
 465         array->nr = 0;
 466         for (src = 0; src < nr; src++) {
 467                 if (!contains_object(array, objects[src].item,
 468                                      objects[src].name)) {
 469                         if (src != array->nr)
 470                                 objects[array->nr] = objects[src];
 471                         array->nr++;
 472                 } else {
 473                         object_array_release_entry(&objects[src]);
 474                 }
 475         }
 476 }
 477
 478 void clear_object_flags(unsigned flags)
 479 {
 480         int i;
 481
 482         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 483                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 484                 if (obj)
 485                         obj->flags &= ~flags;
 486         }
 487 }
 488
 489 void repo_clear_commit_marks(struct repository *r, unsigned int flags)
 490 {
 491         int i;
 492
 493         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 494                 struct object *obj = r->parsed_objects->obj_hash[i];
 495                 if (obj && obj->type == OBJ_COMMIT)
 496                         obj->flags &= ~flags;
 497         }
 498 }
 499
 500 struct parsed_object_pool *parsed_object_pool_new(void)
 501 {
 502         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 503         memset(o, 0, sizeof(*o));
 504
 505         o->blob_state = allocate_alloc_state();
 506         o->tree_state = allocate_alloc_state();
 507         o->commit_state = allocate_alloc_state();
 508         o->tag_state = allocate_alloc_state();
 509         o->object_state = allocate_alloc_state();
 510
 511         o->is_shallow = -1;
 512         CALLOC_ARRAY(o->shallow_stat, 1);
 513
 514         o->buffer_slab = allocate_commit_buffer_slab();
 515
 516         return o;
 517 }
 518
 519 struct raw_object_store *raw_object_store_new(void)
 520 {
 521         struct raw_object_store *o = xmalloc(sizeof(*o));
 522
 523         memset(o, 0, sizeof(*o));
 524         INIT_LIST_HEAD(&o->packed_git_mru);
 525         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
 526         pthread_mutex_init(&o->replace_mutex, NULL);
 527         return o;
 528 }
 529
 530 void free_object_directory(struct object_directory *odb)
 531 {
 532         free(odb->path);
 533         odb_clear_loose_cache(odb);
 534         free(odb);
 535 }
 536
 537 static void free_object_directories(struct raw_object_store *o)
 538 {
 539         while (o->odb) {
 540                 struct object_directory *next;
 541
 542                 next = o->odb->next;
 543                 free_object_directory(o->odb);
 544                 o->odb = next;
 545         }
 546         kh_destroy_odb_path_map(o->odb_by_path);
 547         o->odb_by_path = NULL;
 548 }
 549
 550 void raw_object_store_clear(struct raw_object_store *o)
 551 {
 552         FREE_AND_NULL(o->alternate_db);
 553
 554         oidmap_free(o->replace_map, 1);
 555         FREE_AND_NULL(o->replace_map);
 556         pthread_mutex_destroy(&o->replace_mutex);
 557
 558         free_commit_graph(o->commit_graph);
 559         o->commit_graph = NULL;
 560         o->commit_graph_attempted = 0;
 561
 562         free_object_directories(o);
 563         o->odb_tail = NULL;
 564         o->loaded_alternates = 0;
 565
 566         INIT_LIST_HEAD(&o->packed_git_mru);
 567         close_object_store(o);
 568         o->packed_git = NULL;
 569
 570         hashmap_clear(&o->pack_map);
 571 }
 572
 573 void parsed_object_pool_clear(struct parsed_object_pool *o)
 574 {
 575         /*
 576          * As objects are allocated in slabs (see alloc.c), we do
 577          * not need to free each object, but each slab instead.
 578          *
 579          * Before doing so, we need to free any additional memory
 580          * the objects may hold.
 581          */
 582         unsigned i;
 583
 584         for (i = 0; i < o->obj_hash_size; i++) {
 585                 struct object *obj = o->obj_hash[i];
 586
 587                 if (!obj)
 588                         continue;
 589
 590                 if (obj->type == OBJ_TREE)
 591                         free_tree_buffer((struct tree*)obj);
 592                 else if (obj->type == OBJ_COMMIT)
 593                         release_commit_memory(o, (struct commit*)obj);
 594                 else if (obj->type == OBJ_TAG)
 595                         release_tag_memory((struct tag*)obj);
 596         }
 597
 598         FREE_AND_NULL(o->obj_hash);
 599         o->obj_hash_size = 0;
 600
 601         free_commit_buffer_slab(o->buffer_slab);
 602         o->buffer_slab = NULL;
 603
 604         clear_alloc_state(o->blob_state);
 605         clear_alloc_state(o->tree_state);
 606         clear_alloc_state(o->commit_state);
 607         clear_alloc_state(o->tag_state);
 608         clear_alloc_state(o->object_state);
 609         stat_validity_clear(o->shallow_stat);
 610         FREE_AND_NULL(o->blob_state);
 611         FREE_AND_NULL(o->tree_state);
 612         FREE_AND_NULL(o->commit_state);
 613         FREE_AND_NULL(o->tag_state);
 614         FREE_AND_NULL(o->object_state);
 615         FREE_AND_NULL(o->shallow_stat);
 616 }