object.c

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