object.c

   1 #include "git-compat-util.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 "statinfo.h"
  10 #include "tree.h"
  11 #include "commit.h"
  12 #include "tag.h"
  13 #include "alloc.h"
  14 #include "packfile.h"
  15 #include "commit-graph.h"
  16
  17 unsigned int get_max_object_index(void)
  18 {
  19         return the_repository->parsed_objects->obj_hash_size;
  20 }
  21
  22 struct object *get_indexed_object(unsigned int idx)
  23 {
  24         return the_repository->parsed_objects->obj_hash[idx];
  25 }
  26
  27 static const char *object_type_strings[] = {
  28         NULL,           /* OBJ_NONE = 0 */
  29         "commit",       /* OBJ_COMMIT = 1 */
  30         "tree",         /* OBJ_TREE = 2 */
  31         "blob",         /* OBJ_BLOB = 3 */
  32         "tag",          /* OBJ_TAG = 4 */
  33 };
  34
  35 const char *type_name(unsigned int type)
  36 {
  37         if (type >= ARRAY_SIZE(object_type_strings))
  38                 return NULL;
  39         return object_type_strings[type];
  40 }
  41
  42 int type_from_string_gently(const char *str, ssize_t len, int gentle)
  43 {
  44         int i;
  45
  46         if (len < 0)
  47                 len = strlen(str);
  48
  49         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  50                 if (!xstrncmpz(object_type_strings[i], str, len))
  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         int discard_tree = !!(flags & PARSE_OBJECT_DISCARD_TREE);
 275         unsigned long size;
 276         enum object_type type;
 277         int eaten;
 278         const struct object_id *repl = lookup_replace_object(r, oid);
 279         void *buffer;
 280         struct object *obj;
 281
 282         obj = lookup_object(r, oid);
 283         if (obj && obj->parsed)
 284                 return obj;
 285
 286         if (skip_hash) {
 287                 struct commit *commit = lookup_commit_in_graph(r, repl);
 288                 if (commit)
 289                         return &commit->object;
 290         }
 291
 292         if ((!obj || obj->type == OBJ_BLOB) &&
 293             oid_object_info(r, oid, NULL) == OBJ_BLOB) {
 294                 if (!skip_hash && stream_object_signature(r, repl) < 0) {
 295                         error(_("hash mismatch %s"), oid_to_hex(oid));
 296                         return NULL;
 297                 }
 298                 parse_blob_buffer(lookup_blob(r, oid));
 299                 return lookup_object(r, oid);
 300         }
 301
 302         /*
 303          * If the caller does not care about the tree buffer and does not
 304          * care about checking the hash, we can simply verify that we
 305          * have the on-disk object with the correct type.
 306          */
 307         if (skip_hash && discard_tree &&
 308             (!obj || obj->type == OBJ_TREE) &&
 309             oid_object_info(r, oid, NULL) == OBJ_TREE) {
 310                 return &lookup_tree(r, oid)->object;
 311         }
 312
 313         buffer = repo_read_object_file(r, oid, &type, &size);
 314         if (buffer) {
 315                 if (!skip_hash &&
 316                     check_object_signature(r, repl, buffer, size, type) < 0) {
 317                         free(buffer);
 318                         error(_("hash mismatch %s"), oid_to_hex(repl));
 319                         return NULL;
 320                 }
 321
 322                 obj = parse_object_buffer(r, oid, type, size,
 323                                           buffer, &eaten);
 324                 if (!eaten)
 325                         free(buffer);
 326                 if (discard_tree && type == OBJ_TREE)
 327                         free_tree_buffer((struct tree *)obj);
 328                 return obj;
 329         }
 330         return NULL;
 331 }
 332
 333 struct object *parse_object(struct repository *r, const struct object_id *oid)
 334 {
 335         return parse_object_with_flags(r, oid, 0);
 336 }
 337
 338 struct object_list *object_list_insert(struct object *item,
 339                                        struct object_list **list_p)
 340 {
 341         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 342         new_list->item = item;
 343         new_list->next = *list_p;
 344         *list_p = new_list;
 345         return new_list;
 346 }
 347
 348 int object_list_contains(struct object_list *list, struct object *obj)
 349 {
 350         while (list) {
 351                 if (list->item == obj)
 352                         return 1;
 353                 list = list->next;
 354         }
 355         return 0;
 356 }
 357
 358 void object_list_free(struct object_list **list)
 359 {
 360         while (*list) {
 361                 struct object_list *p = *list;
 362                 *list = p->next;
 363                 free(p);
 364         }
 365 }
 366
 367 /*
 368  * A zero-length string to which object_array_entry::name can be
 369  * initialized without requiring a malloc/free.
 370  */
 371 static char object_array_slopbuf[1];
 372
 373 void object_array_init(struct object_array *array)
 374 {
 375         struct object_array blank = OBJECT_ARRAY_INIT;
 376         memcpy(array, &blank, sizeof(*array));
 377 }
 378
 379 void add_object_array_with_path(struct object *obj, const char *name,
 380                                 struct object_array *array,
 381                                 unsigned mode, const char *path)
 382 {
 383         unsigned nr = array->nr;
 384         unsigned alloc = array->alloc;
 385         struct object_array_entry *objects = array->objects;
 386         struct object_array_entry *entry;
 387
 388         if (nr >= alloc) {
 389                 alloc = (alloc + 32) * 2;
 390                 REALLOC_ARRAY(objects, alloc);
 391                 array->alloc = alloc;
 392                 array->objects = objects;
 393         }
 394         entry = &objects[nr];
 395         entry->item = obj;
 396         if (!name)
 397                 entry->name = NULL;
 398         else if (!*name)
 399                 /* Use our own empty string instead of allocating one: */
 400                 entry->name = object_array_slopbuf;
 401         else
 402                 entry->name = xstrdup(name);
 403         entry->mode = mode;
 404         if (path)
 405                 entry->path = xstrdup(path);
 406         else
 407                 entry->path = NULL;
 408         array->nr = ++nr;
 409 }
 410
 411 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 412 {
 413         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 414 }
 415
 416 /*
 417  * Free all memory associated with an entry; the result is
 418  * in an unspecified state and should not be examined.
 419  */
 420 static void object_array_release_entry(struct object_array_entry *ent)
 421 {
 422         if (ent->name != object_array_slopbuf)
 423                 free(ent->name);
 424         free(ent->path);
 425 }
 426
 427 struct object *object_array_pop(struct object_array *array)
 428 {
 429         struct object *ret;
 430
 431         if (!array->nr)
 432                 return NULL;
 433
 434         ret = array->objects[array->nr - 1].item;
 435         object_array_release_entry(&array->objects[array->nr - 1]);
 436         array->nr--;
 437         return ret;
 438 }
 439
 440 void object_array_filter(struct object_array *array,
 441                          object_array_each_func_t want, void *cb_data)
 442 {
 443         unsigned nr = array->nr, src, dst;
 444         struct object_array_entry *objects = array->objects;
 445
 446         for (src = dst = 0; src < nr; src++) {
 447                 if (want(&objects[src], cb_data)) {
 448                         if (src != dst)
 449                                 objects[dst] = objects[src];
 450                         dst++;
 451                 } else {
 452                         object_array_release_entry(&objects[src]);
 453                 }
 454         }
 455         array->nr = dst;
 456 }
 457
 458 void object_array_clear(struct object_array *array)
 459 {
 460         int i;
 461         for (i = 0; i < array->nr; i++)
 462                 object_array_release_entry(&array->objects[i]);
 463         FREE_AND_NULL(array->objects);
 464         array->nr = array->alloc = 0;
 465 }
 466
 467 /*
 468  * Return true if array already contains an entry.
 469  */
 470 static int contains_object(struct object_array *array,
 471                            const struct object *item, const char *name)
 472 {
 473         unsigned nr = array->nr, i;
 474         struct object_array_entry *object = array->objects;
 475
 476         for (i = 0; i < nr; i++, object++)
 477                 if (item == object->item && !strcmp(object->name, name))
 478                         return 1;
 479         return 0;
 480 }
 481
 482 void object_array_remove_duplicates(struct object_array *array)
 483 {
 484         unsigned nr = array->nr, src;
 485         struct object_array_entry *objects = array->objects;
 486
 487         array->nr = 0;
 488         for (src = 0; src < nr; src++) {
 489                 if (!contains_object(array, objects[src].item,
 490                                      objects[src].name)) {
 491                         if (src != array->nr)
 492                                 objects[array->nr] = objects[src];
 493                         array->nr++;
 494                 } else {
 495                         object_array_release_entry(&objects[src]);
 496                 }
 497         }
 498 }
 499
 500 void clear_object_flags(unsigned flags)
 501 {
 502         int i;
 503
 504         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 505                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 506                 if (obj)
 507                         obj->flags &= ~flags;
 508         }
 509 }
 510
 511 void repo_clear_commit_marks(struct repository *r, unsigned int flags)
 512 {
 513         int i;
 514
 515         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 516                 struct object *obj = r->parsed_objects->obj_hash[i];
 517                 if (obj && obj->type == OBJ_COMMIT)
 518                         obj->flags &= ~flags;
 519         }
 520 }
 521
 522 struct parsed_object_pool *parsed_object_pool_new(void)
 523 {
 524         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 525         memset(o, 0, sizeof(*o));
 526
 527         o->blob_state = allocate_alloc_state();
 528         o->tree_state = allocate_alloc_state();
 529         o->commit_state = allocate_alloc_state();
 530         o->tag_state = allocate_alloc_state();
 531         o->object_state = allocate_alloc_state();
 532
 533         o->is_shallow = -1;
 534         CALLOC_ARRAY(o->shallow_stat, 1);
 535
 536         o->buffer_slab = allocate_commit_buffer_slab();
 537
 538         return o;
 539 }
 540
 541 struct raw_object_store *raw_object_store_new(void)
 542 {
 543         struct raw_object_store *o = xmalloc(sizeof(*o));
 544
 545         memset(o, 0, sizeof(*o));
 546         INIT_LIST_HEAD(&o->packed_git_mru);
 547         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
 548         pthread_mutex_init(&o->replace_mutex, NULL);
 549         return o;
 550 }
 551
 552 void free_object_directory(struct object_directory *odb)
 553 {
 554         free(odb->path);
 555         odb_clear_loose_cache(odb);
 556         free(odb);
 557 }
 558
 559 static void free_object_directories(struct raw_object_store *o)
 560 {
 561         while (o->odb) {
 562                 struct object_directory *next;
 563
 564                 next = o->odb->next;
 565                 free_object_directory(o->odb);
 566                 o->odb = next;
 567         }
 568         kh_destroy_odb_path_map(o->odb_by_path);
 569         o->odb_by_path = NULL;
 570 }
 571
 572 void raw_object_store_clear(struct raw_object_store *o)
 573 {
 574         FREE_AND_NULL(o->alternate_db);
 575
 576         oidmap_free(o->replace_map, 1);
 577         FREE_AND_NULL(o->replace_map);
 578         pthread_mutex_destroy(&o->replace_mutex);
 579
 580         free_commit_graph(o->commit_graph);
 581         o->commit_graph = NULL;
 582         o->commit_graph_attempted = 0;
 583
 584         free_object_directories(o);
 585         o->odb_tail = NULL;
 586         o->loaded_alternates = 0;
 587
 588         INIT_LIST_HEAD(&o->packed_git_mru);
 589         close_object_store(o);
 590         o->packed_git = NULL;
 591
 592         hashmap_clear(&o->pack_map);
 593 }
 594
 595 void parsed_object_pool_clear(struct parsed_object_pool *o)
 596 {
 597         /*
 598          * As objects are allocated in slabs (see alloc.c), we do
 599          * not need to free each object, but each slab instead.
 600          *
 601          * Before doing so, we need to free any additional memory
 602          * the objects may hold.
 603          */
 604         unsigned i;
 605
 606         for (i = 0; i < o->obj_hash_size; i++) {
 607                 struct object *obj = o->obj_hash[i];
 608
 609                 if (!obj)
 610                         continue;
 611
 612                 if (obj->type == OBJ_TREE)
 613                         free_tree_buffer((struct tree*)obj);
 614                 else if (obj->type == OBJ_COMMIT)
 615                         release_commit_memory(o, (struct commit*)obj);
 616                 else if (obj->type == OBJ_TAG)
 617                         release_tag_memory((struct tag*)obj);
 618         }
 619
 620         FREE_AND_NULL(o->obj_hash);
 621         o->obj_hash_size = 0;
 622
 623         free_commit_buffer_slab(o->buffer_slab);
 624         o->buffer_slab = NULL;
 625
 626         clear_alloc_state(o->blob_state);
 627         clear_alloc_state(o->tree_state);
 628         clear_alloc_state(o->commit_state);
 629         clear_alloc_state(o->tag_state);
 630         clear_alloc_state(o->object_state);
 631         stat_validity_clear(o->shallow_stat);
 632         FREE_AND_NULL(o->blob_state);
 633         FREE_AND_NULL(o->tree_state);
 634         FREE_AND_NULL(o->commit_state);
 635         FREE_AND_NULL(o->tag_state);
 636         FREE_AND_NULL(o->object_state);
 637         FREE_AND_NULL(o->shallow_stat);
 638 }