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                         parse_blob_buffer(blob);
 216                         obj = &blob->object;
 217                 }
 218         } else if (type == OBJ_TREE) {
 219                 struct tree *tree = lookup_tree(r, oid);
 220                 if (tree) {
 221                         obj = &tree->object;
 222                         if (!tree->buffer)
 223                                 tree->object.parsed = 0;
 224                         if (!tree->object.parsed) {
 225                                 if (parse_tree_buffer(tree, buffer, size))
 226                                         return NULL;
 227                                 *eaten_p = 1;
 228                         }
 229                 }
 230         } else if (type == OBJ_COMMIT) {
 231                 struct commit *commit = lookup_commit(r, oid);
 232                 if (commit) {
 233                         if (parse_commit_buffer(r, commit, buffer, size, 1))
 234                                 return NULL;
 235                         if (save_commit_buffer &&
 236                             !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) &&
 289             oid_object_info(r, oid, NULL) == OBJ_BLOB) {
 290                 if (!skip_hash && stream_object_signature(r, repl) < 0) {
 291                         error(_("hash mismatch %s"), oid_to_hex(oid));
 292                         return NULL;
 293                 }
 294                 parse_blob_buffer(lookup_blob(r, oid));
 295                 return lookup_object(r, oid);
 296         }
 297
 298         buffer = repo_read_object_file(r, oid, &type, &size);
 299         if (buffer) {
 300                 if (!skip_hash &&
 301                     check_object_signature(r, repl, buffer, size, type) < 0) {
 302                         free(buffer);
 303                         error(_("hash mismatch %s"), oid_to_hex(repl));
 304                         return NULL;
 305                 }
 306
 307                 obj = parse_object_buffer(r, oid, type, size,
 308                                           buffer, &eaten);
 309                 if (!eaten)
 310                         free(buffer);
 311                 return obj;
 312         }
 313         return NULL;
 314 }
 315
 316 struct object *parse_object(struct repository *r, const struct object_id *oid)
 317 {
 318         return parse_object_with_flags(r, oid, 0);
 319 }
 320
 321 struct object_list *object_list_insert(struct object *item,
 322                                        struct object_list **list_p)
 323 {
 324         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 325         new_list->item = item;
 326         new_list->next = *list_p;
 327         *list_p = new_list;
 328         return new_list;
 329 }
 330
 331 int object_list_contains(struct object_list *list, struct object *obj)
 332 {
 333         while (list) {
 334                 if (list->item == obj)
 335                         return 1;
 336                 list = list->next;
 337         }
 338         return 0;
 339 }
 340
 341 void object_list_free(struct object_list **list)
 342 {
 343         while (*list) {
 344                 struct object_list *p = *list;
 345                 *list = p->next;
 346                 free(p);
 347         }
 348 }
 349
 350 /*
 351  * A zero-length string to which object_array_entry::name can be
 352  * initialized without requiring a malloc/free.
 353  */
 354 static char object_array_slopbuf[1];
 355
 356 void add_object_array_with_path(struct object *obj, const char *name,
 357                                 struct object_array *array,
 358                                 unsigned mode, const char *path)
 359 {
 360         unsigned nr = array->nr;
 361         unsigned alloc = array->alloc;
 362         struct object_array_entry *objects = array->objects;
 363         struct object_array_entry *entry;
 364
 365         if (nr >= alloc) {
 366                 alloc = (alloc + 32) * 2;
 367                 REALLOC_ARRAY(objects, alloc);
 368                 array->alloc = alloc;
 369                 array->objects = objects;
 370         }
 371         entry = &objects[nr];
 372         entry->item = obj;
 373         if (!name)
 374                 entry->name = NULL;
 375         else if (!*name)
 376                 /* Use our own empty string instead of allocating one: */
 377                 entry->name = object_array_slopbuf;
 378         else
 379                 entry->name = xstrdup(name);
 380         entry->mode = mode;
 381         if (path)
 382                 entry->path = xstrdup(path);
 383         else
 384                 entry->path = NULL;
 385         array->nr = ++nr;
 386 }
 387
 388 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 389 {
 390         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 391 }
 392
 393 /*
 394  * Free all memory associated with an entry; the result is
 395  * in an unspecified state and should not be examined.
 396  */
 397 static void object_array_release_entry(struct object_array_entry *ent)
 398 {
 399         if (ent->name != object_array_slopbuf)
 400                 free(ent->name);
 401         free(ent->path);
 402 }
 403
 404 struct object *object_array_pop(struct object_array *array)
 405 {
 406         struct object *ret;
 407
 408         if (!array->nr)
 409                 return NULL;
 410
 411         ret = array->objects[array->nr - 1].item;
 412         object_array_release_entry(&array->objects[array->nr - 1]);
 413         array->nr--;
 414         return ret;
 415 }
 416
 417 void object_array_filter(struct object_array *array,
 418                          object_array_each_func_t want, void *cb_data)
 419 {
 420         unsigned nr = array->nr, src, dst;
 421         struct object_array_entry *objects = array->objects;
 422
 423         for (src = dst = 0; src < nr; src++) {
 424                 if (want(&objects[src], cb_data)) {
 425                         if (src != dst)
 426                                 objects[dst] = objects[src];
 427                         dst++;
 428                 } else {
 429                         object_array_release_entry(&objects[src]);
 430                 }
 431         }
 432         array->nr = dst;
 433 }
 434
 435 void object_array_clear(struct object_array *array)
 436 {
 437         int i;
 438         for (i = 0; i < array->nr; i++)
 439                 object_array_release_entry(&array->objects[i]);
 440         FREE_AND_NULL(array->objects);
 441         array->nr = array->alloc = 0;
 442 }
 443
 444 /*
 445  * Return true if array already contains an entry.
 446  */
 447 static int contains_object(struct object_array *array,
 448                            const struct object *item, const char *name)
 449 {
 450         unsigned nr = array->nr, i;
 451         struct object_array_entry *object = array->objects;
 452
 453         for (i = 0; i < nr; i++, object++)
 454                 if (item == object->item && !strcmp(object->name, name))
 455                         return 1;
 456         return 0;
 457 }
 458
 459 void object_array_remove_duplicates(struct object_array *array)
 460 {
 461         unsigned nr = array->nr, src;
 462         struct object_array_entry *objects = array->objects;
 463
 464         array->nr = 0;
 465         for (src = 0; src < nr; src++) {
 466                 if (!contains_object(array, objects[src].item,
 467                                      objects[src].name)) {
 468                         if (src != array->nr)
 469                                 objects[array->nr] = objects[src];
 470                         array->nr++;
 471                 } else {
 472                         object_array_release_entry(&objects[src]);
 473                 }
 474         }
 475 }
 476
 477 void clear_object_flags(unsigned flags)
 478 {
 479         int i;
 480
 481         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 482                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 483                 if (obj)
 484                         obj->flags &= ~flags;
 485         }
 486 }
 487
 488 void repo_clear_commit_marks(struct repository *r, unsigned int flags)
 489 {
 490         int i;
 491
 492         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 493                 struct object *obj = r->parsed_objects->obj_hash[i];
 494                 if (obj && obj->type == OBJ_COMMIT)
 495                         obj->flags &= ~flags;
 496         }
 497 }
 498
 499 struct parsed_object_pool *parsed_object_pool_new(void)
 500 {
 501         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 502         memset(o, 0, sizeof(*o));
 503
 504         o->blob_state = allocate_alloc_state();
 505         o->tree_state = allocate_alloc_state();
 506         o->commit_state = allocate_alloc_state();
 507         o->tag_state = allocate_alloc_state();
 508         o->object_state = allocate_alloc_state();
 509
 510         o->is_shallow = -1;
 511         CALLOC_ARRAY(o->shallow_stat, 1);
 512
 513         o->buffer_slab = allocate_commit_buffer_slab();
 514
 515         return o;
 516 }
 517
 518 struct raw_object_store *raw_object_store_new(void)
 519 {
 520         struct raw_object_store *o = xmalloc(sizeof(*o));
 521
 522         memset(o, 0, sizeof(*o));
 523         INIT_LIST_HEAD(&o->packed_git_mru);
 524         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
 525         pthread_mutex_init(&o->replace_mutex, NULL);
 526         return o;
 527 }
 528
 529 void free_object_directory(struct object_directory *odb)
 530 {
 531         free(odb->path);
 532         odb_clear_loose_cache(odb);
 533         free(odb);
 534 }
 535
 536 static void free_object_directories(struct raw_object_store *o)
 537 {
 538         while (o->odb) {
 539                 struct object_directory *next;
 540
 541                 next = o->odb->next;
 542                 free_object_directory(o->odb);
 543                 o->odb = next;
 544         }
 545         kh_destroy_odb_path_map(o->odb_by_path);
 546         o->odb_by_path = NULL;
 547 }
 548
 549 void raw_object_store_clear(struct raw_object_store *o)
 550 {
 551         FREE_AND_NULL(o->alternate_db);
 552
 553         oidmap_free(o->replace_map, 1);
 554         FREE_AND_NULL(o->replace_map);
 555         pthread_mutex_destroy(&o->replace_mutex);
 556
 557         free_commit_graph(o->commit_graph);
 558         o->commit_graph = NULL;
 559         o->commit_graph_attempted = 0;
 560
 561         free_object_directories(o);
 562         o->odb_tail = NULL;
 563         o->loaded_alternates = 0;
 564
 565         INIT_LIST_HEAD(&o->packed_git_mru);
 566         close_object_store(o);
 567         o->packed_git = NULL;
 568
 569         hashmap_clear(&o->pack_map);
 570 }
 571
 572 void parsed_object_pool_clear(struct parsed_object_pool *o)
 573 {
 574         /*
 575          * As objects are allocated in slabs (see alloc.c), we do
 576          * not need to free each object, but each slab instead.
 577          *
 578          * Before doing so, we need to free any additional memory
 579          * the objects may hold.
 580          */
 581         unsigned i;
 582
 583         for (i = 0; i < o->obj_hash_size; i++) {
 584                 struct object *obj = o->obj_hash[i];
 585
 586                 if (!obj)
 587                         continue;
 588
 589                 if (obj->type == OBJ_TREE)
 590                         free_tree_buffer((struct tree*)obj);
 591                 else if (obj->type == OBJ_COMMIT)
 592                         release_commit_memory(o, (struct commit*)obj);
 593                 else if (obj->type == OBJ_TAG)
 594                         release_tag_memory((struct tag*)obj);
 595         }
 596
 597         FREE_AND_NULL(o->obj_hash);
 598         o->obj_hash_size = 0;
 599
 600         free_commit_buffer_slab(o->buffer_slab);
 601         o->buffer_slab = NULL;
 602
 603         clear_alloc_state(o->blob_state);
 604         clear_alloc_state(o->tree_state);
 605         clear_alloc_state(o->commit_state);
 606         clear_alloc_state(o->tag_state);
 607         clear_alloc_state(o->object_state);
 608         stat_validity_clear(o->shallow_stat);
 609         FREE_AND_NULL(o->blob_state);
 610         FREE_AND_NULL(o->tree_state);
 611         FREE_AND_NULL(o->commit_state);
 612         FREE_AND_NULL(o->tag_state);
 613         FREE_AND_NULL(o->object_state);
 614         FREE_AND_NULL(o->shallow_stat);
 615 }