object.c

   1 #define USE_THE_REPOSITORY_VARIABLE
   2 #define DISABLE_SIGN_COMPARE_WARNINGS
   3
   4 #include "git-compat-util.h"
   5 #include "gettext.h"
   6 #include "hex.h"
   7 #include "object.h"
   8 #include "replace-object.h"
   9 #include "object-file.h"
  10 #include "object-store.h"
  11 #include "blob.h"
  12 #include "statinfo.h"
  13 #include "tree.h"
  14 #include "commit.h"
  15 #include "tag.h"
  16 #include "alloc.h"
  17 #include "packfile.h"
  18 #include "commit-graph.h"
  19 #include "loose.h"
  20
  21 unsigned int get_max_object_index(void)
  22 {
  23         return the_repository->parsed_objects->obj_hash_size;
  24 }
  25
  26 struct object *get_indexed_object(unsigned int idx)
  27 {
  28         return the_repository->parsed_objects->obj_hash[idx];
  29 }
  30
  31 static const char *object_type_strings[] = {
  32         NULL,           /* OBJ_NONE = 0 */
  33         "commit",       /* OBJ_COMMIT = 1 */
  34         "tree",         /* OBJ_TREE = 2 */
  35         "blob",         /* OBJ_BLOB = 3 */
  36         "tag",          /* OBJ_TAG = 4 */
  37 };
  38
  39 const char *type_name(unsigned int type)
  40 {
  41         if (type >= ARRAY_SIZE(object_type_strings))
  42                 return NULL;
  43         return object_type_strings[type];
  44 }
  45
  46 int type_from_string_gently(const char *str, ssize_t len, int gentle)
  47 {
  48         int i;
  49
  50         if (len < 0)
  51                 len = strlen(str);
  52
  53         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  54                 if (!xstrncmpz(object_type_strings[i], str, len))
  55                         return i;
  56
  57         if (gentle)
  58                 return -1;
  59
  60         die(_("invalid object type \"%s\""), str);
  61 }
  62
  63 /*
  64  * Return a numerical hash value between 0 and n-1 for the object with
  65  * the specified sha1.  n must be a power of 2.  Please note that the
  66  * return value is *not* consistent across computer architectures.
  67  */
  68 static unsigned int hash_obj(const struct object_id *oid, unsigned int n)
  69 {
  70         return oidhash(oid) & (n - 1);
  71 }
  72
  73 /*
  74  * Insert obj into the hash table hash, which has length size (which
  75  * must be a power of 2).  On collisions, simply overflow to the next
  76  * empty bucket.
  77  */
  78 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  79 {
  80         unsigned int j = hash_obj(&obj->oid, size);
  81
  82         while (hash[j]) {
  83                 j++;
  84                 if (j >= size)
  85                         j = 0;
  86         }
  87         hash[j] = obj;
  88 }
  89
  90 /*
  91  * Look up the record for the given sha1 in the hash map stored in
  92  * obj_hash.  Return NULL if it was not found.
  93  */
  94 struct object *lookup_object(struct repository *r, const struct object_id *oid)
  95 {
  96         unsigned int i, first;
  97         struct object *obj;
  98
  99         if (!r->parsed_objects->obj_hash)
 100                 return NULL;
 101
 102         first = i = hash_obj(oid, r->parsed_objects->obj_hash_size);
 103         while ((obj = r->parsed_objects->obj_hash[i]) != NULL) {
 104                 if (oideq(oid, &obj->oid))
 105                         break;
 106                 i++;
 107                 if (i == r->parsed_objects->obj_hash_size)
 108                         i = 0;
 109         }
 110         if (obj && i != first) {
 111                 /*
 112                  * Move object to where we started to look for it so
 113                  * that we do not need to walk the hash table the next
 114                  * time we look for it.
 115                  */
 116                 SWAP(r->parsed_objects->obj_hash[i],
 117                      r->parsed_objects->obj_hash[first]);
 118         }
 119         return obj;
 120 }
 121
 122 /*
 123  * Increase the size of the hash map stored in obj_hash to the next
 124  * power of 2 (but at least 32).  Copy the existing values to the new
 125  * hash map.
 126  */
 127 static void grow_object_hash(struct repository *r)
 128 {
 129         int i;
 130         /*
 131          * Note that this size must always be power-of-2 to match hash_obj
 132          * above.
 133          */
 134         int new_hash_size = r->parsed_objects->obj_hash_size < 32 ? 32 : 2 * r->parsed_objects->obj_hash_size;
 135         struct object **new_hash;
 136
 137         CALLOC_ARRAY(new_hash, new_hash_size);
 138         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 139                 struct object *obj = r->parsed_objects->obj_hash[i];
 140
 141                 if (!obj)
 142                         continue;
 143                 insert_obj_hash(obj, new_hash, new_hash_size);
 144         }
 145         free(r->parsed_objects->obj_hash);
 146         r->parsed_objects->obj_hash = new_hash;
 147         r->parsed_objects->obj_hash_size = new_hash_size;
 148 }
 149
 150 void *create_object(struct repository *r, const struct object_id *oid, void *o)
 151 {
 152         struct object *obj = o;
 153
 154         obj->parsed = 0;
 155         obj->flags = 0;
 156         oidcpy(&obj->oid, oid);
 157
 158         if (r->parsed_objects->obj_hash_size - 1 <= r->parsed_objects->nr_objs * 2)
 159                 grow_object_hash(r);
 160
 161         insert_obj_hash(obj, r->parsed_objects->obj_hash,
 162                         r->parsed_objects->obj_hash_size);
 163         r->parsed_objects->nr_objs++;
 164         return obj;
 165 }
 166
 167 void *object_as_type(struct object *obj, enum object_type type, int quiet)
 168 {
 169         if (obj->type == type)
 170                 return obj;
 171         else if (obj->type == OBJ_NONE) {
 172                 if (type == OBJ_COMMIT)
 173                         init_commit_node((struct commit *) obj);
 174                 else
 175                         obj->type = type;
 176                 return obj;
 177         }
 178         else {
 179                 if (!quiet)
 180                         error(_("object %s is a %s, not a %s"),
 181                               oid_to_hex(&obj->oid),
 182                               type_name(obj->type), type_name(type));
 183                 return NULL;
 184         }
 185 }
 186
 187 struct object *lookup_unknown_object(struct repository *r, const struct object_id *oid)
 188 {
 189         struct object *obj = lookup_object(r, oid);
 190         if (!obj)
 191                 obj = create_object(r, oid, alloc_object_node(r));
 192         return obj;
 193 }
 194
 195 struct object *lookup_object_by_type(struct repository *r,
 196                             const struct object_id *oid,
 197                             enum object_type type)
 198 {
 199         switch (type) {
 200         case OBJ_COMMIT:
 201                 return (struct object *)lookup_commit(r, oid);
 202         case OBJ_TREE:
 203                 return (struct object *)lookup_tree(r, oid);
 204         case OBJ_TAG:
 205                 return (struct object *)lookup_tag(r, oid);
 206         case OBJ_BLOB:
 207                 return (struct object *)lookup_blob(r, oid);
 208         default:
 209                 BUG("unknown object type %d", type);
 210         }
 211 }
 212
 213 enum peel_status peel_object(struct repository *r,
 214                              const struct object_id *name,
 215                              struct object_id *oid)
 216 {
 217         struct object *o = lookup_unknown_object(r, name);
 218
 219         if (o->type == OBJ_NONE) {
 220                 int type = oid_object_info(r, name, NULL);
 221                 if (type < 0 || !object_as_type(o, type, 0))
 222                         return PEEL_INVALID;
 223         }
 224
 225         if (o->type != OBJ_TAG)
 226                 return PEEL_NON_TAG;
 227
 228         o = deref_tag_noverify(r, o);
 229         if (!o)
 230                 return PEEL_INVALID;
 231
 232         oidcpy(oid, &o->oid);
 233         return PEEL_PEELED;
 234 }
 235
 236 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)
 237 {
 238         struct object *obj;
 239         *eaten_p = 0;
 240
 241         obj = NULL;
 242         if (type == OBJ_BLOB) {
 243                 struct blob *blob = lookup_blob(r, oid);
 244                 if (blob) {
 245                         parse_blob_buffer(blob);
 246                         obj = &blob->object;
 247                 }
 248         } else if (type == OBJ_TREE) {
 249                 struct tree *tree = lookup_tree(r, oid);
 250                 if (tree) {
 251                         obj = &tree->object;
 252                         if (!tree->buffer)
 253                                 tree->object.parsed = 0;
 254                         if (!tree->object.parsed) {
 255                                 if (parse_tree_buffer(tree, buffer, size))
 256                                         return NULL;
 257                                 *eaten_p = 1;
 258                         }
 259                 }
 260         } else if (type == OBJ_COMMIT) {
 261                 struct commit *commit = lookup_commit(r, oid);
 262                 if (commit) {
 263                         if (parse_commit_buffer(r, commit, buffer, size, 1))
 264                                 return NULL;
 265                         if (save_commit_buffer &&
 266                             !get_cached_commit_buffer(r, commit, NULL)) {
 267                                 set_commit_buffer(r, commit, buffer, size);
 268                                 *eaten_p = 1;
 269                         }
 270                         obj = &commit->object;
 271                 }
 272         } else if (type == OBJ_TAG) {
 273                 struct tag *tag = lookup_tag(r, oid);
 274                 if (tag) {
 275                         if (parse_tag_buffer(r, tag, buffer, size))
 276                                return NULL;
 277                         obj = &tag->object;
 278                 }
 279         } else {
 280                 warning(_("object %s has unknown type id %d"), oid_to_hex(oid), type);
 281                 obj = NULL;
 282         }
 283         return obj;
 284 }
 285
 286 struct object *parse_object_or_die(const struct object_id *oid,
 287                                    const char *name)
 288 {
 289         struct object *o = parse_object(the_repository, oid);
 290         if (o)
 291                 return o;
 292
 293         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
 294 }
 295
 296 struct object *parse_object_with_flags(struct repository *r,
 297                                        const struct object_id *oid,
 298                                        enum parse_object_flags flags)
 299 {
 300         int skip_hash = !!(flags & PARSE_OBJECT_SKIP_HASH_CHECK);
 301         int discard_tree = !!(flags & PARSE_OBJECT_DISCARD_TREE);
 302         unsigned long size;
 303         enum object_type type;
 304         int eaten;
 305         const struct object_id *repl = lookup_replace_object(r, oid);
 306         void *buffer;
 307         struct object *obj;
 308
 309         obj = lookup_object(r, oid);
 310         if (obj && obj->parsed)
 311                 return obj;
 312
 313         if (skip_hash) {
 314                 struct commit *commit = lookup_commit_in_graph(r, repl);
 315                 if (commit)
 316                         return &commit->object;
 317         }
 318
 319         if ((!obj || obj->type == OBJ_BLOB) &&
 320             oid_object_info(r, oid, NULL) == OBJ_BLOB) {
 321                 if (!skip_hash && stream_object_signature(r, repl) < 0) {
 322                         error(_("hash mismatch %s"), oid_to_hex(oid));
 323                         return NULL;
 324                 }
 325                 parse_blob_buffer(lookup_blob(r, oid));
 326                 return lookup_object(r, oid);
 327         }
 328
 329         /*
 330          * If the caller does not care about the tree buffer and does not
 331          * care about checking the hash, we can simply verify that we
 332          * have the on-disk object with the correct type.
 333          */
 334         if (skip_hash && discard_tree &&
 335             (!obj || obj->type == OBJ_TREE) &&
 336             oid_object_info(r, oid, NULL) == OBJ_TREE) {
 337                 return &lookup_tree(r, oid)->object;
 338         }
 339
 340         buffer = repo_read_object_file(r, oid, &type, &size);
 341         if (buffer) {
 342                 if (!skip_hash &&
 343                     check_object_signature(r, repl, buffer, size, type) < 0) {
 344                         free(buffer);
 345                         error(_("hash mismatch %s"), oid_to_hex(repl));
 346                         return NULL;
 347                 }
 348
 349                 obj = parse_object_buffer(r, oid, type, size,
 350                                           buffer, &eaten);
 351                 if (!eaten)
 352                         free(buffer);
 353                 if (discard_tree && type == OBJ_TREE)
 354                         free_tree_buffer((struct tree *)obj);
 355                 return obj;
 356         }
 357         return NULL;
 358 }
 359
 360 struct object *parse_object(struct repository *r, const struct object_id *oid)
 361 {
 362         return parse_object_with_flags(r, oid, 0);
 363 }
 364
 365 struct object_list *object_list_insert(struct object *item,
 366                                        struct object_list **list_p)
 367 {
 368         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 369         new_list->item = item;
 370         new_list->next = *list_p;
 371         *list_p = new_list;
 372         return new_list;
 373 }
 374
 375 int object_list_contains(struct object_list *list, struct object *obj)
 376 {
 377         while (list) {
 378                 if (list->item == obj)
 379                         return 1;
 380                 list = list->next;
 381         }
 382         return 0;
 383 }
 384
 385 void object_list_free(struct object_list **list)
 386 {
 387         while (*list) {
 388                 struct object_list *p = *list;
 389                 *list = p->next;
 390                 free(p);
 391         }
 392 }
 393
 394 /*
 395  * A zero-length string to which object_array_entry::name can be
 396  * initialized without requiring a malloc/free.
 397  */
 398 static char object_array_slopbuf[1];
 399
 400 void object_array_init(struct object_array *array)
 401 {
 402         struct object_array blank = OBJECT_ARRAY_INIT;
 403         memcpy(array, &blank, sizeof(*array));
 404 }
 405
 406 void add_object_array_with_path(struct object *obj, const char *name,
 407                                 struct object_array *array,
 408                                 unsigned mode, const char *path)
 409 {
 410         unsigned nr = array->nr;
 411         unsigned alloc = array->alloc;
 412         struct object_array_entry *objects = array->objects;
 413         struct object_array_entry *entry;
 414
 415         if (nr >= alloc) {
 416                 alloc = (alloc + 32) * 2;
 417                 REALLOC_ARRAY(objects, alloc);
 418                 array->alloc = alloc;
 419                 array->objects = objects;
 420         }
 421         entry = &objects[nr];
 422         entry->item = obj;
 423         if (!name)
 424                 entry->name = NULL;
 425         else if (!*name)
 426                 /* Use our own empty string instead of allocating one: */
 427                 entry->name = object_array_slopbuf;
 428         else
 429                 entry->name = xstrdup(name);
 430         entry->mode = mode;
 431         if (path)
 432                 entry->path = xstrdup(path);
 433         else
 434                 entry->path = NULL;
 435         array->nr = ++nr;
 436 }
 437
 438 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 439 {
 440         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 441 }
 442
 443 /*
 444  * Free all memory associated with an entry; the result is
 445  * in an unspecified state and should not be examined.
 446  */
 447 static void object_array_release_entry(struct object_array_entry *ent)
 448 {
 449         if (ent->name != object_array_slopbuf)
 450                 free(ent->name);
 451         free(ent->path);
 452 }
 453
 454 struct object *object_array_pop(struct object_array *array)
 455 {
 456         struct object *ret;
 457
 458         if (!array->nr)
 459                 return NULL;
 460
 461         ret = array->objects[array->nr - 1].item;
 462         object_array_release_entry(&array->objects[array->nr - 1]);
 463         array->nr--;
 464         return ret;
 465 }
 466
 467 void object_array_filter(struct object_array *array,
 468                          object_array_each_func_t want, void *cb_data)
 469 {
 470         unsigned nr = array->nr, src, dst;
 471         struct object_array_entry *objects = array->objects;
 472
 473         for (src = dst = 0; src < nr; src++) {
 474                 if (want(&objects[src], cb_data)) {
 475                         if (src != dst)
 476                                 objects[dst] = objects[src];
 477                         dst++;
 478                 } else {
 479                         object_array_release_entry(&objects[src]);
 480                 }
 481         }
 482         array->nr = dst;
 483 }
 484
 485 void object_array_clear(struct object_array *array)
 486 {
 487         int i;
 488         for (i = 0; i < array->nr; i++)
 489                 object_array_release_entry(&array->objects[i]);
 490         FREE_AND_NULL(array->objects);
 491         array->nr = array->alloc = 0;
 492 }
 493
 494 /*
 495  * Return true if array already contains an entry.
 496  */
 497 static int contains_object(struct object_array *array,
 498                            const struct object *item, const char *name)
 499 {
 500         unsigned nr = array->nr, i;
 501         struct object_array_entry *object = array->objects;
 502
 503         for (i = 0; i < nr; i++, object++)
 504                 if (item == object->item && !strcmp(object->name, name))
 505                         return 1;
 506         return 0;
 507 }
 508
 509 void object_array_remove_duplicates(struct object_array *array)
 510 {
 511         unsigned nr = array->nr, src;
 512         struct object_array_entry *objects = array->objects;
 513
 514         array->nr = 0;
 515         for (src = 0; src < nr; src++) {
 516                 if (!contains_object(array, objects[src].item,
 517                                      objects[src].name)) {
 518                         if (src != array->nr)
 519                                 objects[array->nr] = objects[src];
 520                         array->nr++;
 521                 } else {
 522                         object_array_release_entry(&objects[src]);
 523                 }
 524         }
 525 }
 526
 527 void clear_object_flags(unsigned flags)
 528 {
 529         int i;
 530
 531         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 532                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 533                 if (obj)
 534                         obj->flags &= ~flags;
 535         }
 536 }
 537
 538 void repo_clear_commit_marks(struct repository *r, unsigned int flags)
 539 {
 540         int i;
 541
 542         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 543                 struct object *obj = r->parsed_objects->obj_hash[i];
 544                 if (obj && obj->type == OBJ_COMMIT)
 545                         obj->flags &= ~flags;
 546         }
 547 }
 548
 549 struct parsed_object_pool *parsed_object_pool_new(struct repository *repo)
 550 {
 551         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 552         memset(o, 0, sizeof(*o));
 553
 554         o->repo = repo;
 555         o->blob_state = allocate_alloc_state();
 556         o->tree_state = allocate_alloc_state();
 557         o->commit_state = allocate_alloc_state();
 558         o->tag_state = allocate_alloc_state();
 559         o->object_state = allocate_alloc_state();
 560
 561         o->is_shallow = -1;
 562         CALLOC_ARRAY(o->shallow_stat, 1);
 563
 564         o->buffer_slab = allocate_commit_buffer_slab();
 565
 566         return o;
 567 }
 568
 569 struct raw_object_store *raw_object_store_new(void)
 570 {
 571         struct raw_object_store *o = xmalloc(sizeof(*o));
 572
 573         memset(o, 0, sizeof(*o));
 574         INIT_LIST_HEAD(&o->packed_git_mru);
 575         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
 576         pthread_mutex_init(&o->replace_mutex, NULL);
 577         return o;
 578 }
 579
 580 void free_object_directory(struct object_directory *odb)
 581 {
 582         free(odb->path);
 583         odb_clear_loose_cache(odb);
 584         loose_object_map_clear(&odb->loose_map);
 585         free(odb);
 586 }
 587
 588 static void free_object_directories(struct raw_object_store *o)
 589 {
 590         while (o->odb) {
 591                 struct object_directory *next;
 592
 593                 next = o->odb->next;
 594                 free_object_directory(o->odb);
 595                 o->odb = next;
 596         }
 597         kh_destroy_odb_path_map(o->odb_by_path);
 598         o->odb_by_path = NULL;
 599 }
 600
 601 void raw_object_store_clear(struct raw_object_store *o)
 602 {
 603         FREE_AND_NULL(o->alternate_db);
 604
 605         oidmap_free(o->replace_map, 1);
 606         FREE_AND_NULL(o->replace_map);
 607         pthread_mutex_destroy(&o->replace_mutex);
 608
 609         free_commit_graph(o->commit_graph);
 610         o->commit_graph = NULL;
 611         o->commit_graph_attempted = 0;
 612
 613         free_object_directories(o);
 614         o->odb_tail = NULL;
 615         o->loaded_alternates = 0;
 616
 617         INIT_LIST_HEAD(&o->packed_git_mru);
 618         close_object_store(o);
 619
 620         /*
 621          * `close_object_store()` only closes the packfiles, but doesn't free
 622          * them. We thus have to do this manually.
 623          */
 624         for (struct packed_git *p = o->packed_git, *next; p; p = next) {
 625                 next = p->next;
 626                 free(p);
 627         }
 628         o->packed_git = NULL;
 629
 630         hashmap_clear(&o->pack_map);
 631 }
 632
 633 void parsed_object_pool_reset_commit_grafts(struct parsed_object_pool *o)
 634 {
 635         for (int i = 0; i < o->grafts_nr; i++) {
 636                 unparse_commit(o->repo, &o->grafts[i]->oid);
 637                 free(o->grafts[i]);
 638         }
 639         o->grafts_nr = 0;
 640         o->commit_graft_prepared = 0;
 641 }
 642
 643 void parsed_object_pool_clear(struct parsed_object_pool *o)
 644 {
 645         /*
 646          * As objects are allocated in slabs (see alloc.c), we do
 647          * not need to free each object, but each slab instead.
 648          *
 649          * Before doing so, we need to free any additional memory
 650          * the objects may hold.
 651          */
 652         unsigned i;
 653
 654         for (i = 0; i < o->obj_hash_size; i++) {
 655                 struct object *obj = o->obj_hash[i];
 656
 657                 if (!obj)
 658                         continue;
 659
 660                 if (obj->type == OBJ_TREE)
 661                         free_tree_buffer((struct tree*)obj);
 662                 else if (obj->type == OBJ_COMMIT)
 663                         release_commit_memory(o, (struct commit*)obj);
 664                 else if (obj->type == OBJ_TAG)
 665                         release_tag_memory((struct tag*)obj);
 666         }
 667
 668         FREE_AND_NULL(o->obj_hash);
 669         o->obj_hash_size = 0;
 670
 671         free_commit_buffer_slab(o->buffer_slab);
 672         o->buffer_slab = NULL;
 673
 674         parsed_object_pool_reset_commit_grafts(o);
 675         clear_alloc_state(o->blob_state);
 676         clear_alloc_state(o->tree_state);
 677         clear_alloc_state(o->commit_state);
 678         clear_alloc_state(o->tag_state);
 679         clear_alloc_state(o->object_state);
 680         stat_validity_clear(o->shallow_stat);
 681         FREE_AND_NULL(o->blob_state);
 682         FREE_AND_NULL(o->tree_state);
 683         FREE_AND_NULL(o->commit_state);
 684         FREE_AND_NULL(o->tag_state);
 685         FREE_AND_NULL(o->object_state);
 686         FREE_AND_NULL(o->shallow_stat);
 687 }