object.c

   1 #define USE_THE_REPOSITORY_VARIABLE
   2
   3 #include "git-compat-util.h"
   4 #include "gettext.h"
   5 #include "hex.h"
   6 #include "object.h"
   7 #include "replace-object.h"
   8 #include "object-file.h"
   9 #include "object-store.h"
  10 #include "blob.h"
  11 #include "statinfo.h"
  12 #include "tree.h"
  13 #include "commit.h"
  14 #include "tag.h"
  15 #include "alloc.h"
  16 #include "packfile.h"
  17 #include "commit-graph.h"
  18 #include "loose.h"
  19
  20 unsigned int get_max_object_index(void)
  21 {
  22         return the_repository->parsed_objects->obj_hash_size;
  23 }
  24
  25 struct object *get_indexed_object(unsigned int idx)
  26 {
  27         return the_repository->parsed_objects->obj_hash[idx];
  28 }
  29
  30 static const char *object_type_strings[] = {
  31         NULL,           /* OBJ_NONE = 0 */
  32         "commit",       /* OBJ_COMMIT = 1 */
  33         "tree",         /* OBJ_TREE = 2 */
  34         "blob",         /* OBJ_BLOB = 3 */
  35         "tag",          /* OBJ_TAG = 4 */
  36 };
  37
  38 const char *type_name(unsigned int type)
  39 {
  40         if (type >= ARRAY_SIZE(object_type_strings))
  41                 return NULL;
  42         return object_type_strings[type];
  43 }
  44
  45 int type_from_string_gently(const char *str, ssize_t len, int gentle)
  46 {
  47         int i;
  48
  49         if (len < 0)
  50                 len = strlen(str);
  51
  52         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  53                 if (!xstrncmpz(object_type_strings[i], str, len))
  54                         return i;
  55
  56         if (gentle)
  57                 return -1;
  58
  59         die(_("invalid object type \"%s\""), str);
  60 }
  61
  62 /*
  63  * Return a numerical hash value between 0 and n-1 for the object with
  64  * the specified sha1.  n must be a power of 2.  Please note that the
  65  * return value is *not* consistent across computer architectures.
  66  */
  67 static unsigned int hash_obj(const struct object_id *oid, unsigned int n)
  68 {
  69         return oidhash(oid) & (n - 1);
  70 }
  71
  72 /*
  73  * Insert obj into the hash table hash, which has length size (which
  74  * must be a power of 2).  On collisions, simply overflow to the next
  75  * empty bucket.
  76  */
  77 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  78 {
  79         unsigned int j = hash_obj(&obj->oid, size);
  80
  81         while (hash[j]) {
  82                 j++;
  83                 if (j >= size)
  84                         j = 0;
  85         }
  86         hash[j] = obj;
  87 }
  88
  89 /*
  90  * Look up the record for the given sha1 in the hash map stored in
  91  * obj_hash.  Return NULL if it was not found.
  92  */
  93 struct object *lookup_object(struct repository *r, const struct object_id *oid)
  94 {
  95         unsigned int i, first;
  96         struct object *obj;
  97
  98         if (!r->parsed_objects->obj_hash)
  99                 return NULL;
 100
 101         first = i = hash_obj(oid, r->parsed_objects->obj_hash_size);
 102         while ((obj = r->parsed_objects->obj_hash[i]) != NULL) {
 103                 if (oideq(oid, &obj->oid))
 104                         break;
 105                 i++;
 106                 if (i == r->parsed_objects->obj_hash_size)
 107                         i = 0;
 108         }
 109         if (obj && i != first) {
 110                 /*
 111                  * Move object to where we started to look for it so
 112                  * that we do not need to walk the hash table the next
 113                  * time we look for it.
 114                  */
 115                 SWAP(r->parsed_objects->obj_hash[i],
 116                      r->parsed_objects->obj_hash[first]);
 117         }
 118         return obj;
 119 }
 120
 121 /*
 122  * Increase the size of the hash map stored in obj_hash to the next
 123  * power of 2 (but at least 32).  Copy the existing values to the new
 124  * hash map.
 125  */
 126 static void grow_object_hash(struct repository *r)
 127 {
 128         int i;
 129         /*
 130          * Note that this size must always be power-of-2 to match hash_obj
 131          * above.
 132          */
 133         int new_hash_size = r->parsed_objects->obj_hash_size < 32 ? 32 : 2 * r->parsed_objects->obj_hash_size;
 134         struct object **new_hash;
 135
 136         CALLOC_ARRAY(new_hash, new_hash_size);
 137         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 138                 struct object *obj = r->parsed_objects->obj_hash[i];
 139
 140                 if (!obj)
 141                         continue;
 142                 insert_obj_hash(obj, new_hash, new_hash_size);
 143         }
 144         free(r->parsed_objects->obj_hash);
 145         r->parsed_objects->obj_hash = new_hash;
 146         r->parsed_objects->obj_hash_size = new_hash_size;
 147 }
 148
 149 void *create_object(struct repository *r, const struct object_id *oid, void *o)
 150 {
 151         struct object *obj = o;
 152
 153         obj->parsed = 0;
 154         obj->flags = 0;
 155         oidcpy(&obj->oid, oid);
 156
 157         if (r->parsed_objects->obj_hash_size - 1 <= r->parsed_objects->nr_objs * 2)
 158                 grow_object_hash(r);
 159
 160         insert_obj_hash(obj, r->parsed_objects->obj_hash,
 161                         r->parsed_objects->obj_hash_size);
 162         r->parsed_objects->nr_objs++;
 163         return obj;
 164 }
 165
 166 void *object_as_type(struct object *obj, enum object_type type, int quiet)
 167 {
 168         if (obj->type == type)
 169                 return obj;
 170         else if (obj->type == OBJ_NONE) {
 171                 if (type == OBJ_COMMIT)
 172                         init_commit_node((struct commit *) obj);
 173                 else
 174                         obj->type = type;
 175                 return obj;
 176         }
 177         else {
 178                 if (!quiet)
 179                         error(_("object %s is a %s, not a %s"),
 180                               oid_to_hex(&obj->oid),
 181                               type_name(obj->type), type_name(type));
 182                 return NULL;
 183         }
 184 }
 185
 186 struct object *lookup_unknown_object(struct repository *r, const struct object_id *oid)
 187 {
 188         struct object *obj = lookup_object(r, oid);
 189         if (!obj)
 190                 obj = create_object(r, oid, alloc_object_node(r));
 191         return obj;
 192 }
 193
 194 struct object *lookup_object_by_type(struct repository *r,
 195                             const struct object_id *oid,
 196                             enum object_type type)
 197 {
 198         switch (type) {
 199         case OBJ_COMMIT:
 200                 return (struct object *)lookup_commit(r, oid);
 201         case OBJ_TREE:
 202                 return (struct object *)lookup_tree(r, oid);
 203         case OBJ_TAG:
 204                 return (struct object *)lookup_tag(r, oid);
 205         case OBJ_BLOB:
 206                 return (struct object *)lookup_blob(r, oid);
 207         default:
 208                 BUG("unknown object type %d", type);
 209         }
 210 }
 211
 212 enum peel_status peel_object(struct repository *r,
 213                              const struct object_id *name,
 214                              struct object_id *oid)
 215 {
 216         struct object *o = lookup_unknown_object(r, name);
 217
 218         if (o->type == OBJ_NONE) {
 219                 int type = oid_object_info(r, name, NULL);
 220                 if (type < 0 || !object_as_type(o, type, 0))
 221                         return PEEL_INVALID;
 222         }
 223
 224         if (o->type != OBJ_TAG)
 225                 return PEEL_NON_TAG;
 226
 227         o = deref_tag_noverify(r, o);
 228         if (!o)
 229                 return PEEL_INVALID;
 230
 231         oidcpy(oid, &o->oid);
 232         return PEEL_PEELED;
 233 }
 234
 235 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)
 236 {
 237         struct object *obj;
 238         *eaten_p = 0;
 239
 240         obj = NULL;
 241         if (type == OBJ_BLOB) {
 242                 struct blob *blob = lookup_blob(r, oid);
 243                 if (blob) {
 244                         parse_blob_buffer(blob);
 245                         obj = &blob->object;
 246                 }
 247         } else if (type == OBJ_TREE) {
 248                 struct tree *tree = lookup_tree(r, oid);
 249                 if (tree) {
 250                         obj = &tree->object;
 251                         if (!tree->buffer)
 252                                 tree->object.parsed = 0;
 253                         if (!tree->object.parsed) {
 254                                 if (parse_tree_buffer(tree, buffer, size))
 255                                         return NULL;
 256                                 *eaten_p = 1;
 257                         }
 258                 }
 259         } else if (type == OBJ_COMMIT) {
 260                 struct commit *commit = lookup_commit(r, oid);
 261                 if (commit) {
 262                         if (parse_commit_buffer(r, commit, buffer, size, 1))
 263                                 return NULL;
 264                         if (save_commit_buffer &&
 265                             !get_cached_commit_buffer(r, commit, NULL)) {
 266                                 set_commit_buffer(r, commit, buffer, size);
 267                                 *eaten_p = 1;
 268                         }
 269                         obj = &commit->object;
 270                 }
 271         } else if (type == OBJ_TAG) {
 272                 struct tag *tag = lookup_tag(r, oid);
 273                 if (tag) {
 274                         if (parse_tag_buffer(r, tag, buffer, size))
 275                                return NULL;
 276                         obj = &tag->object;
 277                 }
 278         } else {
 279                 warning(_("object %s has unknown type id %d"), oid_to_hex(oid), type);
 280                 obj = NULL;
 281         }
 282         return obj;
 283 }
 284
 285 struct object *parse_object_or_die(const struct object_id *oid,
 286                                    const char *name)
 287 {
 288         struct object *o = parse_object(the_repository, oid);
 289         if (o)
 290                 return o;
 291
 292         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
 293 }
 294
 295 struct object *parse_object_with_flags(struct repository *r,
 296                                        const struct object_id *oid,
 297                                        enum parse_object_flags flags)
 298 {
 299         int skip_hash = !!(flags & PARSE_OBJECT_SKIP_HASH_CHECK);
 300         int discard_tree = !!(flags & PARSE_OBJECT_DISCARD_TREE);
 301         unsigned long size;
 302         enum object_type type;
 303         int eaten;
 304         const struct object_id *repl = lookup_replace_object(r, oid);
 305         void *buffer;
 306         struct object *obj;
 307
 308         obj = lookup_object(r, oid);
 309         if (obj && obj->parsed)
 310                 return obj;
 311
 312         if (skip_hash) {
 313                 struct commit *commit = lookup_commit_in_graph(r, repl);
 314                 if (commit)
 315                         return &commit->object;
 316         }
 317
 318         if ((!obj || obj->type == OBJ_BLOB) &&
 319             oid_object_info(r, oid, NULL) == OBJ_BLOB) {
 320                 if (!skip_hash && stream_object_signature(r, repl) < 0) {
 321                         error(_("hash mismatch %s"), oid_to_hex(oid));
 322                         return NULL;
 323                 }
 324                 parse_blob_buffer(lookup_blob(r, oid));
 325                 return lookup_object(r, oid);
 326         }
 327
 328         /*
 329          * If the caller does not care about the tree buffer and does not
 330          * care about checking the hash, we can simply verify that we
 331          * have the on-disk object with the correct type.
 332          */
 333         if (skip_hash && discard_tree &&
 334             (!obj || obj->type == OBJ_TREE) &&
 335             oid_object_info(r, oid, NULL) == OBJ_TREE) {
 336                 return &lookup_tree(r, oid)->object;
 337         }
 338
 339         buffer = repo_read_object_file(r, oid, &type, &size);
 340         if (buffer) {
 341                 if (!skip_hash &&
 342                     check_object_signature(r, repl, buffer, size, type) < 0) {
 343                         free(buffer);
 344                         error(_("hash mismatch %s"), oid_to_hex(repl));
 345                         return NULL;
 346                 }
 347
 348                 obj = parse_object_buffer(r, oid, type, size,
 349                                           buffer, &eaten);
 350                 if (!eaten)
 351                         free(buffer);
 352                 if (discard_tree && type == OBJ_TREE)
 353                         free_tree_buffer((struct tree *)obj);
 354                 return obj;
 355         }
 356         return NULL;
 357 }
 358
 359 struct object *parse_object(struct repository *r, const struct object_id *oid)
 360 {
 361         return parse_object_with_flags(r, oid, 0);
 362 }
 363
 364 struct object_list *object_list_insert(struct object *item,
 365                                        struct object_list **list_p)
 366 {
 367         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 368         new_list->item = item;
 369         new_list->next = *list_p;
 370         *list_p = new_list;
 371         return new_list;
 372 }
 373
 374 int object_list_contains(struct object_list *list, struct object *obj)
 375 {
 376         while (list) {
 377                 if (list->item == obj)
 378                         return 1;
 379                 list = list->next;
 380         }
 381         return 0;
 382 }
 383
 384 void object_list_free(struct object_list **list)
 385 {
 386         while (*list) {
 387                 struct object_list *p = *list;
 388                 *list = p->next;
 389                 free(p);
 390         }
 391 }
 392
 393 /*
 394  * A zero-length string to which object_array_entry::name can be
 395  * initialized without requiring a malloc/free.
 396  */
 397 static char object_array_slopbuf[1];
 398
 399 void object_array_init(struct object_array *array)
 400 {
 401         struct object_array blank = OBJECT_ARRAY_INIT;
 402         memcpy(array, &blank, sizeof(*array));
 403 }
 404
 405 void add_object_array_with_path(struct object *obj, const char *name,
 406                                 struct object_array *array,
 407                                 unsigned mode, const char *path)
 408 {
 409         unsigned nr = array->nr;
 410         unsigned alloc = array->alloc;
 411         struct object_array_entry *objects = array->objects;
 412         struct object_array_entry *entry;
 413
 414         if (nr >= alloc) {
 415                 alloc = (alloc + 32) * 2;
 416                 REALLOC_ARRAY(objects, alloc);
 417                 array->alloc = alloc;
 418                 array->objects = objects;
 419         }
 420         entry = &objects[nr];
 421         entry->item = obj;
 422         if (!name)
 423                 entry->name = NULL;
 424         else if (!*name)
 425                 /* Use our own empty string instead of allocating one: */
 426                 entry->name = object_array_slopbuf;
 427         else
 428                 entry->name = xstrdup(name);
 429         entry->mode = mode;
 430         if (path)
 431                 entry->path = xstrdup(path);
 432         else
 433                 entry->path = NULL;
 434         array->nr = ++nr;
 435 }
 436
 437 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 438 {
 439         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 440 }
 441
 442 /*
 443  * Free all memory associated with an entry; the result is
 444  * in an unspecified state and should not be examined.
 445  */
 446 static void object_array_release_entry(struct object_array_entry *ent)
 447 {
 448         if (ent->name != object_array_slopbuf)
 449                 free(ent->name);
 450         free(ent->path);
 451 }
 452
 453 struct object *object_array_pop(struct object_array *array)
 454 {
 455         struct object *ret;
 456
 457         if (!array->nr)
 458                 return NULL;
 459
 460         ret = array->objects[array->nr - 1].item;
 461         object_array_release_entry(&array->objects[array->nr - 1]);
 462         array->nr--;
 463         return ret;
 464 }
 465
 466 void object_array_filter(struct object_array *array,
 467                          object_array_each_func_t want, void *cb_data)
 468 {
 469         unsigned nr = array->nr, src, dst;
 470         struct object_array_entry *objects = array->objects;
 471
 472         for (src = dst = 0; src < nr; src++) {
 473                 if (want(&objects[src], cb_data)) {
 474                         if (src != dst)
 475                                 objects[dst] = objects[src];
 476                         dst++;
 477                 } else {
 478                         object_array_release_entry(&objects[src]);
 479                 }
 480         }
 481         array->nr = dst;
 482 }
 483
 484 void object_array_clear(struct object_array *array)
 485 {
 486         int i;
 487         for (i = 0; i < array->nr; i++)
 488                 object_array_release_entry(&array->objects[i]);
 489         FREE_AND_NULL(array->objects);
 490         array->nr = array->alloc = 0;
 491 }
 492
 493 /*
 494  * Return true if array already contains an entry.
 495  */
 496 static int contains_object(struct object_array *array,
 497                            const struct object *item, const char *name)
 498 {
 499         unsigned nr = array->nr, i;
 500         struct object_array_entry *object = array->objects;
 501
 502         for (i = 0; i < nr; i++, object++)
 503                 if (item == object->item && !strcmp(object->name, name))
 504                         return 1;
 505         return 0;
 506 }
 507
 508 void object_array_remove_duplicates(struct object_array *array)
 509 {
 510         unsigned nr = array->nr, src;
 511         struct object_array_entry *objects = array->objects;
 512
 513         array->nr = 0;
 514         for (src = 0; src < nr; src++) {
 515                 if (!contains_object(array, objects[src].item,
 516                                      objects[src].name)) {
 517                         if (src != array->nr)
 518                                 objects[array->nr] = objects[src];
 519                         array->nr++;
 520                 } else {
 521                         object_array_release_entry(&objects[src]);
 522                 }
 523         }
 524 }
 525
 526 void clear_object_flags(unsigned flags)
 527 {
 528         int i;
 529
 530         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 531                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 532                 if (obj)
 533                         obj->flags &= ~flags;
 534         }
 535 }
 536
 537 void repo_clear_commit_marks(struct repository *r, unsigned int flags)
 538 {
 539         int i;
 540
 541         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 542                 struct object *obj = r->parsed_objects->obj_hash[i];
 543                 if (obj && obj->type == OBJ_COMMIT)
 544                         obj->flags &= ~flags;
 545         }
 546 }
 547
 548 struct parsed_object_pool *parsed_object_pool_new(void)
 549 {
 550         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 551         memset(o, 0, sizeof(*o));
 552
 553         o->blob_state = allocate_alloc_state();
 554         o->tree_state = allocate_alloc_state();
 555         o->commit_state = allocate_alloc_state();
 556         o->tag_state = allocate_alloc_state();
 557         o->object_state = allocate_alloc_state();
 558
 559         o->is_shallow = -1;
 560         CALLOC_ARRAY(o->shallow_stat, 1);
 561
 562         o->buffer_slab = allocate_commit_buffer_slab();
 563
 564         return o;
 565 }
 566
 567 struct raw_object_store *raw_object_store_new(void)
 568 {
 569         struct raw_object_store *o = xmalloc(sizeof(*o));
 570
 571         memset(o, 0, sizeof(*o));
 572         INIT_LIST_HEAD(&o->packed_git_mru);
 573         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
 574         pthread_mutex_init(&o->replace_mutex, NULL);
 575         return o;
 576 }
 577
 578 void free_object_directory(struct object_directory *odb)
 579 {
 580         free(odb->path);
 581         odb_clear_loose_cache(odb);
 582         loose_object_map_clear(&odb->loose_map);
 583         free(odb);
 584 }
 585
 586 static void free_object_directories(struct raw_object_store *o)
 587 {
 588         while (o->odb) {
 589                 struct object_directory *next;
 590
 591                 next = o->odb->next;
 592                 free_object_directory(o->odb);
 593                 o->odb = next;
 594         }
 595         kh_destroy_odb_path_map(o->odb_by_path);
 596         o->odb_by_path = NULL;
 597 }
 598
 599 void raw_object_store_clear(struct raw_object_store *o)
 600 {
 601         FREE_AND_NULL(o->alternate_db);
 602
 603         oidmap_free(o->replace_map, 1);
 604         FREE_AND_NULL(o->replace_map);
 605         pthread_mutex_destroy(&o->replace_mutex);
 606
 607         free_commit_graph(o->commit_graph);
 608         o->commit_graph = NULL;
 609         o->commit_graph_attempted = 0;
 610
 611         free_object_directories(o);
 612         o->odb_tail = NULL;
 613         o->loaded_alternates = 0;
 614
 615         INIT_LIST_HEAD(&o->packed_git_mru);
 616         close_object_store(o);
 617
 618         /*
 619          * `close_object_store()` only closes the packfiles, but doesn't free
 620          * them. We thus have to do this manually.
 621          */
 622         for (struct packed_git *p = o->packed_git, *next; p; p = next) {
 623                 next = p->next;
 624                 free(p);
 625         }
 626         o->packed_git = NULL;
 627
 628         hashmap_clear(&o->pack_map);
 629 }
 630
 631 void parsed_object_pool_clear(struct parsed_object_pool *o)
 632 {
 633         /*
 634          * As objects are allocated in slabs (see alloc.c), we do
 635          * not need to free each object, but each slab instead.
 636          *
 637          * Before doing so, we need to free any additional memory
 638          * the objects may hold.
 639          */
 640         unsigned i;
 641
 642         for (i = 0; i < o->obj_hash_size; i++) {
 643                 struct object *obj = o->obj_hash[i];
 644
 645                 if (!obj)
 646                         continue;
 647
 648                 if (obj->type == OBJ_TREE)
 649                         free_tree_buffer((struct tree*)obj);
 650                 else if (obj->type == OBJ_COMMIT)
 651                         release_commit_memory(o, (struct commit*)obj);
 652                 else if (obj->type == OBJ_TAG)
 653                         release_tag_memory((struct tag*)obj);
 654         }
 655
 656         FREE_AND_NULL(o->obj_hash);
 657         o->obj_hash_size = 0;
 658
 659         free_commit_buffer_slab(o->buffer_slab);
 660         o->buffer_slab = NULL;
 661
 662         clear_alloc_state(o->blob_state);
 663         clear_alloc_state(o->tree_state);
 664         clear_alloc_state(o->commit_state);
 665         clear_alloc_state(o->tag_state);
 666         clear_alloc_state(o->object_state);
 667         stat_validity_clear(o->shallow_stat);
 668         FREE_AND_NULL(o->blob_state);
 669         FREE_AND_NULL(o->tree_state);
 670         FREE_AND_NULL(o->commit_state);
 671         FREE_AND_NULL(o->tag_state);
 672         FREE_AND_NULL(o->object_state);
 673         FREE_AND_NULL(o->shallow_stat);
 674 }