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                 die("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(struct repository *r, const struct object_id *oid)
 267 {
 268         unsigned long size;
 269         enum object_type type;
 270         int eaten;
 271         const struct object_id *repl = lookup_replace_object(r, oid);
 272         void *buffer;
 273         struct object *obj;
 274
 275         obj = lookup_object(r, oid);
 276         if (obj && obj->parsed)
 277                 return obj;
 278
 279         if ((obj && obj->type == OBJ_BLOB && repo_has_object_file(r, oid)) ||
 280             (!obj && repo_has_object_file(r, oid) &&
 281              oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
 282                 if (check_object_signature(r, repl, NULL, 0, NULL, NULL) < 0) {
 283                         error(_("hash mismatch %s"), oid_to_hex(oid));
 284                         return NULL;
 285                 }
 286                 parse_blob_buffer(lookup_blob(r, oid), NULL, 0);
 287                 return lookup_object(r, oid);
 288         }
 289
 290         buffer = repo_read_object_file(r, oid, &type, &size);
 291         if (buffer) {
 292                 if (check_object_signature(r, repl, buffer, size,
 293                                            type_name(type), NULL) < 0) {
 294                         free(buffer);
 295                         error(_("hash mismatch %s"), oid_to_hex(repl));
 296                         return NULL;
 297                 }
 298
 299                 obj = parse_object_buffer(r, oid, type, size,
 300                                           buffer, &eaten);
 301                 if (!eaten)
 302                         free(buffer);
 303                 return obj;
 304         }
 305         return NULL;
 306 }
 307
 308 struct object_list *object_list_insert(struct object *item,
 309                                        struct object_list **list_p)
 310 {
 311         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 312         new_list->item = item;
 313         new_list->next = *list_p;
 314         *list_p = new_list;
 315         return new_list;
 316 }
 317
 318 int object_list_contains(struct object_list *list, struct object *obj)
 319 {
 320         while (list) {
 321                 if (list->item == obj)
 322                         return 1;
 323                 list = list->next;
 324         }
 325         return 0;
 326 }
 327
 328 void object_list_free(struct object_list **list)
 329 {
 330         while (*list) {
 331                 struct object_list *p = *list;
 332                 *list = p->next;
 333                 free(p);
 334         }
 335 }
 336
 337 /*
 338  * A zero-length string to which object_array_entry::name can be
 339  * initialized without requiring a malloc/free.
 340  */
 341 static char object_array_slopbuf[1];
 342
 343 void add_object_array_with_path(struct object *obj, const char *name,
 344                                 struct object_array *array,
 345                                 unsigned mode, const char *path)
 346 {
 347         unsigned nr = array->nr;
 348         unsigned alloc = array->alloc;
 349         struct object_array_entry *objects = array->objects;
 350         struct object_array_entry *entry;
 351
 352         if (nr >= alloc) {
 353                 alloc = (alloc + 32) * 2;
 354                 REALLOC_ARRAY(objects, alloc);
 355                 array->alloc = alloc;
 356                 array->objects = objects;
 357         }
 358         entry = &objects[nr];
 359         entry->item = obj;
 360         if (!name)
 361                 entry->name = NULL;
 362         else if (!*name)
 363                 /* Use our own empty string instead of allocating one: */
 364                 entry->name = object_array_slopbuf;
 365         else
 366                 entry->name = xstrdup(name);
 367         entry->mode = mode;
 368         if (path)
 369                 entry->path = xstrdup(path);
 370         else
 371                 entry->path = NULL;
 372         array->nr = ++nr;
 373 }
 374
 375 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 376 {
 377         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 378 }
 379
 380 /*
 381  * Free all memory associated with an entry; the result is
 382  * in an unspecified state and should not be examined.
 383  */
 384 static void object_array_release_entry(struct object_array_entry *ent)
 385 {
 386         if (ent->name != object_array_slopbuf)
 387                 free(ent->name);
 388         free(ent->path);
 389 }
 390
 391 struct object *object_array_pop(struct object_array *array)
 392 {
 393         struct object *ret;
 394
 395         if (!array->nr)
 396                 return NULL;
 397
 398         ret = array->objects[array->nr - 1].item;
 399         object_array_release_entry(&array->objects[array->nr - 1]);
 400         array->nr--;
 401         return ret;
 402 }
 403
 404 void object_array_filter(struct object_array *array,
 405                          object_array_each_func_t want, void *cb_data)
 406 {
 407         unsigned nr = array->nr, src, dst;
 408         struct object_array_entry *objects = array->objects;
 409
 410         for (src = dst = 0; src < nr; src++) {
 411                 if (want(&objects[src], cb_data)) {
 412                         if (src != dst)
 413                                 objects[dst] = objects[src];
 414                         dst++;
 415                 } else {
 416                         object_array_release_entry(&objects[src]);
 417                 }
 418         }
 419         array->nr = dst;
 420 }
 421
 422 void object_array_clear(struct object_array *array)
 423 {
 424         int i;
 425         for (i = 0; i < array->nr; i++)
 426                 object_array_release_entry(&array->objects[i]);
 427         FREE_AND_NULL(array->objects);
 428         array->nr = array->alloc = 0;
 429 }
 430
 431 /*
 432  * Return true if array already contains an entry.
 433  */
 434 static int contains_object(struct object_array *array,
 435                            const struct object *item, const char *name)
 436 {
 437         unsigned nr = array->nr, i;
 438         struct object_array_entry *object = array->objects;
 439
 440         for (i = 0; i < nr; i++, object++)
 441                 if (item == object->item && !strcmp(object->name, name))
 442                         return 1;
 443         return 0;
 444 }
 445
 446 void object_array_remove_duplicates(struct object_array *array)
 447 {
 448         unsigned nr = array->nr, src;
 449         struct object_array_entry *objects = array->objects;
 450
 451         array->nr = 0;
 452         for (src = 0; src < nr; src++) {
 453                 if (!contains_object(array, objects[src].item,
 454                                      objects[src].name)) {
 455                         if (src != array->nr)
 456                                 objects[array->nr] = objects[src];
 457                         array->nr++;
 458                 } else {
 459                         object_array_release_entry(&objects[src]);
 460                 }
 461         }
 462 }
 463
 464 void clear_object_flags(unsigned flags)
 465 {
 466         int i;
 467
 468         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 469                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 470                 if (obj)
 471                         obj->flags &= ~flags;
 472         }
 473 }
 474
 475 void repo_clear_commit_marks(struct repository *r, unsigned int flags)
 476 {
 477         int i;
 478
 479         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 480                 struct object *obj = r->parsed_objects->obj_hash[i];
 481                 if (obj && obj->type == OBJ_COMMIT)
 482                         obj->flags &= ~flags;
 483         }
 484 }
 485
 486 struct parsed_object_pool *parsed_object_pool_new(void)
 487 {
 488         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 489         memset(o, 0, sizeof(*o));
 490
 491         o->blob_state = allocate_alloc_state();
 492         o->tree_state = allocate_alloc_state();
 493         o->commit_state = allocate_alloc_state();
 494         o->tag_state = allocate_alloc_state();
 495         o->object_state = allocate_alloc_state();
 496
 497         o->is_shallow = -1;
 498         CALLOC_ARRAY(o->shallow_stat, 1);
 499
 500         o->buffer_slab = allocate_commit_buffer_slab();
 501
 502         return o;
 503 }
 504
 505 struct raw_object_store *raw_object_store_new(void)
 506 {
 507         struct raw_object_store *o = xmalloc(sizeof(*o));
 508
 509         memset(o, 0, sizeof(*o));
 510         INIT_LIST_HEAD(&o->packed_git_mru);
 511         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
 512         pthread_mutex_init(&o->replace_mutex, NULL);
 513         return o;
 514 }
 515
 516 static void free_object_directory(struct object_directory *odb)
 517 {
 518         free(odb->path);
 519         odb_clear_loose_cache(odb);
 520         free(odb);
 521 }
 522
 523 static void free_object_directories(struct raw_object_store *o)
 524 {
 525         while (o->odb) {
 526                 struct object_directory *next;
 527
 528                 next = o->odb->next;
 529                 free_object_directory(o->odb);
 530                 o->odb = next;
 531         }
 532         kh_destroy_odb_path_map(o->odb_by_path);
 533         o->odb_by_path = NULL;
 534 }
 535
 536 void raw_object_store_clear(struct raw_object_store *o)
 537 {
 538         FREE_AND_NULL(o->alternate_db);
 539
 540         oidmap_free(o->replace_map, 1);
 541         FREE_AND_NULL(o->replace_map);
 542         pthread_mutex_destroy(&o->replace_mutex);
 543
 544         free_commit_graph(o->commit_graph);
 545         o->commit_graph = NULL;
 546         o->commit_graph_attempted = 0;
 547
 548         free_object_directories(o);
 549         o->odb_tail = NULL;
 550         o->loaded_alternates = 0;
 551
 552         INIT_LIST_HEAD(&o->packed_git_mru);
 553         close_object_store(o);
 554         o->packed_git = NULL;
 555
 556         hashmap_clear(&o->pack_map);
 557 }
 558
 559 void parsed_object_pool_clear(struct parsed_object_pool *o)
 560 {
 561         /*
 562          * As objects are allocated in slabs (see alloc.c), we do
 563          * not need to free each object, but each slab instead.
 564          *
 565          * Before doing so, we need to free any additional memory
 566          * the objects may hold.
 567          */
 568         unsigned i;
 569
 570         for (i = 0; i < o->obj_hash_size; i++) {
 571                 struct object *obj = o->obj_hash[i];
 572
 573                 if (!obj)
 574                         continue;
 575
 576                 if (obj->type == OBJ_TREE)
 577                         free_tree_buffer((struct tree*)obj);
 578                 else if (obj->type == OBJ_COMMIT)
 579                         release_commit_memory(o, (struct commit*)obj);
 580                 else if (obj->type == OBJ_TAG)
 581                         release_tag_memory((struct tag*)obj);
 582         }
 583
 584         FREE_AND_NULL(o->obj_hash);
 585         o->obj_hash_size = 0;
 586
 587         free_commit_buffer_slab(o->buffer_slab);
 588         o->buffer_slab = NULL;
 589
 590         clear_alloc_state(o->blob_state);
 591         clear_alloc_state(o->tree_state);
 592         clear_alloc_state(o->commit_state);
 593         clear_alloc_state(o->tag_state);
 594         clear_alloc_state(o->object_state);
 595         stat_validity_clear(o->shallow_stat);
 596         FREE_AND_NULL(o->blob_state);
 597         FREE_AND_NULL(o->tree_state);
 598         FREE_AND_NULL(o->commit_state);
 599         FREE_AND_NULL(o->tag_state);
 600         FREE_AND_NULL(o->object_state);
 601         FREE_AND_NULL(o->shallow_stat);
 602 }