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