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 #include "loose.h"
  17
  18 unsigned int get_max_object_index(void)
  19 {
  20         return the_repository->parsed_objects->obj_hash_size;
  21 }
  22
  23 struct object *get_indexed_object(unsigned int idx)
  24 {
  25         return the_repository->parsed_objects->obj_hash[idx];
  26 }
  27
  28 static const char *object_type_strings[] = {
  29         NULL,           /* OBJ_NONE = 0 */
  30         "commit",       /* OBJ_COMMIT = 1 */
  31         "tree",         /* OBJ_TREE = 2 */
  32         "blob",         /* OBJ_BLOB = 3 */
  33         "tag",          /* OBJ_TAG = 4 */
  34 };
  35
  36 const char *type_name(unsigned int type)
  37 {
  38         if (type >= ARRAY_SIZE(object_type_strings))
  39                 return NULL;
  40         return object_type_strings[type];
  41 }
  42
  43 int type_from_string_gently(const char *str, ssize_t len, int gentle)
  44 {
  45         int i;
  46
  47         if (len < 0)
  48                 len = strlen(str);
  49
  50         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  51                 if (!xstrncmpz(object_type_strings[i], str, len))
  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         int discard_tree = !!(flags & PARSE_OBJECT_DISCARD_TREE);
 276         unsigned long size;
 277         enum object_type type;
 278         int eaten;
 279         const struct object_id *repl = lookup_replace_object(r, oid);
 280         void *buffer;
 281         struct object *obj;
 282
 283         obj = lookup_object(r, oid);
 284         if (obj && obj->parsed)
 285                 return obj;
 286
 287         if (skip_hash) {
 288                 struct commit *commit = lookup_commit_in_graph(r, repl);
 289                 if (commit)
 290                         return &commit->object;
 291         }
 292
 293         if ((!obj || obj->type == OBJ_BLOB) &&
 294             oid_object_info(r, oid, NULL) == OBJ_BLOB) {
 295                 if (!skip_hash && stream_object_signature(r, repl) < 0) {
 296                         error(_("hash mismatch %s"), oid_to_hex(oid));
 297                         return NULL;
 298                 }
 299                 parse_blob_buffer(lookup_blob(r, oid));
 300                 return lookup_object(r, oid);
 301         }
 302
 303         /*
 304          * If the caller does not care about the tree buffer and does not
 305          * care about checking the hash, we can simply verify that we
 306          * have the on-disk object with the correct type.
 307          */
 308         if (skip_hash && discard_tree &&
 309             (!obj || obj->type == OBJ_TREE) &&
 310             oid_object_info(r, oid, NULL) == OBJ_TREE) {
 311                 return &lookup_tree(r, oid)->object;
 312         }
 313
 314         buffer = repo_read_object_file(r, oid, &type, &size);
 315         if (buffer) {
 316                 if (!skip_hash &&
 317                     check_object_signature(r, repl, buffer, size, type) < 0) {
 318                         free(buffer);
 319                         error(_("hash mismatch %s"), oid_to_hex(repl));
 320                         return NULL;
 321                 }
 322
 323                 obj = parse_object_buffer(r, oid, type, size,
 324                                           buffer, &eaten);
 325                 if (!eaten)
 326                         free(buffer);
 327                 if (discard_tree && type == OBJ_TREE)
 328                         free_tree_buffer((struct tree *)obj);
 329                 return obj;
 330         }
 331         return NULL;
 332 }
 333
 334 struct object *parse_object(struct repository *r, const struct object_id *oid)
 335 {
 336         return parse_object_with_flags(r, oid, 0);
 337 }
 338
 339 struct object_list *object_list_insert(struct object *item,
 340                                        struct object_list **list_p)
 341 {
 342         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 343         new_list->item = item;
 344         new_list->next = *list_p;
 345         *list_p = new_list;
 346         return new_list;
 347 }
 348
 349 int object_list_contains(struct object_list *list, struct object *obj)
 350 {
 351         while (list) {
 352                 if (list->item == obj)
 353                         return 1;
 354                 list = list->next;
 355         }
 356         return 0;
 357 }
 358
 359 void object_list_free(struct object_list **list)
 360 {
 361         while (*list) {
 362                 struct object_list *p = *list;
 363                 *list = p->next;
 364                 free(p);
 365         }
 366 }
 367
 368 /*
 369  * A zero-length string to which object_array_entry::name can be
 370  * initialized without requiring a malloc/free.
 371  */
 372 static char object_array_slopbuf[1];
 373
 374 void object_array_init(struct object_array *array)
 375 {
 376         struct object_array blank = OBJECT_ARRAY_INIT;
 377         memcpy(array, &blank, sizeof(*array));
 378 }
 379
 380 void add_object_array_with_path(struct object *obj, const char *name,
 381                                 struct object_array *array,
 382                                 unsigned mode, const char *path)
 383 {
 384         unsigned nr = array->nr;
 385         unsigned alloc = array->alloc;
 386         struct object_array_entry *objects = array->objects;
 387         struct object_array_entry *entry;
 388
 389         if (nr >= alloc) {
 390                 alloc = (alloc + 32) * 2;
 391                 REALLOC_ARRAY(objects, alloc);
 392                 array->alloc = alloc;
 393                 array->objects = objects;
 394         }
 395         entry = &objects[nr];
 396         entry->item = obj;
 397         if (!name)
 398                 entry->name = NULL;
 399         else if (!*name)
 400                 /* Use our own empty string instead of allocating one: */
 401                 entry->name = object_array_slopbuf;
 402         else
 403                 entry->name = xstrdup(name);
 404         entry->mode = mode;
 405         if (path)
 406                 entry->path = xstrdup(path);
 407         else
 408                 entry->path = NULL;
 409         array->nr = ++nr;
 410 }
 411
 412 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 413 {
 414         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 415 }
 416
 417 /*
 418  * Free all memory associated with an entry; the result is
 419  * in an unspecified state and should not be examined.
 420  */
 421 static void object_array_release_entry(struct object_array_entry *ent)
 422 {
 423         if (ent->name != object_array_slopbuf)
 424                 free(ent->name);
 425         free(ent->path);
 426 }
 427
 428 struct object *object_array_pop(struct object_array *array)
 429 {
 430         struct object *ret;
 431
 432         if (!array->nr)
 433                 return NULL;
 434
 435         ret = array->objects[array->nr - 1].item;
 436         object_array_release_entry(&array->objects[array->nr - 1]);
 437         array->nr--;
 438         return ret;
 439 }
 440
 441 void object_array_filter(struct object_array *array,
 442                          object_array_each_func_t want, void *cb_data)
 443 {
 444         unsigned nr = array->nr, src, dst;
 445         struct object_array_entry *objects = array->objects;
 446
 447         for (src = dst = 0; src < nr; src++) {
 448                 if (want(&objects[src], cb_data)) {
 449                         if (src != dst)
 450                                 objects[dst] = objects[src];
 451                         dst++;
 452                 } else {
 453                         object_array_release_entry(&objects[src]);
 454                 }
 455         }
 456         array->nr = dst;
 457 }
 458
 459 void object_array_clear(struct object_array *array)
 460 {
 461         int i;
 462         for (i = 0; i < array->nr; i++)
 463                 object_array_release_entry(&array->objects[i]);
 464         FREE_AND_NULL(array->objects);
 465         array->nr = array->alloc = 0;
 466 }
 467
 468 /*
 469  * Return true if array already contains an entry.
 470  */
 471 static int contains_object(struct object_array *array,
 472                            const struct object *item, const char *name)
 473 {
 474         unsigned nr = array->nr, i;
 475         struct object_array_entry *object = array->objects;
 476
 477         for (i = 0; i < nr; i++, object++)
 478                 if (item == object->item && !strcmp(object->name, name))
 479                         return 1;
 480         return 0;
 481 }
 482
 483 void object_array_remove_duplicates(struct object_array *array)
 484 {
 485         unsigned nr = array->nr, src;
 486         struct object_array_entry *objects = array->objects;
 487
 488         array->nr = 0;
 489         for (src = 0; src < nr; src++) {
 490                 if (!contains_object(array, objects[src].item,
 491                                      objects[src].name)) {
 492                         if (src != array->nr)
 493                                 objects[array->nr] = objects[src];
 494                         array->nr++;
 495                 } else {
 496                         object_array_release_entry(&objects[src]);
 497                 }
 498         }
 499 }
 500
 501 void clear_object_flags(unsigned flags)
 502 {
 503         int i;
 504
 505         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 506                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 507                 if (obj)
 508                         obj->flags &= ~flags;
 509         }
 510 }
 511
 512 void repo_clear_commit_marks(struct repository *r, unsigned int flags)
 513 {
 514         int i;
 515
 516         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 517                 struct object *obj = r->parsed_objects->obj_hash[i];
 518                 if (obj && obj->type == OBJ_COMMIT)
 519                         obj->flags &= ~flags;
 520         }
 521 }
 522
 523 struct parsed_object_pool *parsed_object_pool_new(void)
 524 {
 525         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 526         memset(o, 0, sizeof(*o));
 527
 528         o->blob_state = allocate_alloc_state();
 529         o->tree_state = allocate_alloc_state();
 530         o->commit_state = allocate_alloc_state();
 531         o->tag_state = allocate_alloc_state();
 532         o->object_state = allocate_alloc_state();
 533
 534         o->is_shallow = -1;
 535         CALLOC_ARRAY(o->shallow_stat, 1);
 536
 537         o->buffer_slab = allocate_commit_buffer_slab();
 538
 539         return o;
 540 }
 541
 542 struct raw_object_store *raw_object_store_new(void)
 543 {
 544         struct raw_object_store *o = xmalloc(sizeof(*o));
 545
 546         memset(o, 0, sizeof(*o));
 547         INIT_LIST_HEAD(&o->packed_git_mru);
 548         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
 549         pthread_mutex_init(&o->replace_mutex, NULL);
 550         return o;
 551 }
 552
 553 void free_object_directory(struct object_directory *odb)
 554 {
 555         free(odb->path);
 556         odb_clear_loose_cache(odb);
 557         loose_object_map_clear(&odb->loose_map);
 558         free(odb);
 559 }
 560
 561 static void free_object_directories(struct raw_object_store *o)
 562 {
 563         while (o->odb) {
 564                 struct object_directory *next;
 565
 566                 next = o->odb->next;
 567                 free_object_directory(o->odb);
 568                 o->odb = next;
 569         }
 570         kh_destroy_odb_path_map(o->odb_by_path);
 571         o->odb_by_path = NULL;
 572 }
 573
 574 void raw_object_store_clear(struct raw_object_store *o)
 575 {
 576         FREE_AND_NULL(o->alternate_db);
 577
 578         oidmap_free(o->replace_map, 1);
 579         FREE_AND_NULL(o->replace_map);
 580         pthread_mutex_destroy(&o->replace_mutex);
 581
 582         free_commit_graph(o->commit_graph);
 583         o->commit_graph = NULL;
 584         o->commit_graph_attempted = 0;
 585
 586         free_object_directories(o);
 587         o->odb_tail = NULL;
 588         o->loaded_alternates = 0;
 589
 590         INIT_LIST_HEAD(&o->packed_git_mru);
 591         close_object_store(o);
 592         o->packed_git = NULL;
 593
 594         hashmap_clear(&o->pack_map);
 595 }
 596
 597 void parsed_object_pool_clear(struct parsed_object_pool *o)
 598 {
 599         /*
 600          * As objects are allocated in slabs (see alloc.c), we do
 601          * not need to free each object, but each slab instead.
 602          *
 603          * Before doing so, we need to free any additional memory
 604          * the objects may hold.
 605          */
 606         unsigned i;
 607
 608         for (i = 0; i < o->obj_hash_size; i++) {
 609                 struct object *obj = o->obj_hash[i];
 610
 611                 if (!obj)
 612                         continue;
 613
 614                 if (obj->type == OBJ_TREE)
 615                         free_tree_buffer((struct tree*)obj);
 616                 else if (obj->type == OBJ_COMMIT)
 617                         release_commit_memory(o, (struct commit*)obj);
 618                 else if (obj->type == OBJ_TAG)
 619                         release_tag_memory((struct tag*)obj);
 620         }
 621
 622         FREE_AND_NULL(o->obj_hash);
 623         o->obj_hash_size = 0;
 624
 625         free_commit_buffer_slab(o->buffer_slab);
 626         o->buffer_slab = NULL;
 627
 628         clear_alloc_state(o->blob_state);
 629         clear_alloc_state(o->tree_state);
 630         clear_alloc_state(o->commit_state);
 631         clear_alloc_state(o->tag_state);
 632         clear_alloc_state(o->object_state);
 633         stat_validity_clear(o->shallow_stat);
 634         FREE_AND_NULL(o->blob_state);
 635         FREE_AND_NULL(o->tree_state);
 636         FREE_AND_NULL(o->commit_state);
 637         FREE_AND_NULL(o->tag_state);
 638         FREE_AND_NULL(o->object_state);
 639         FREE_AND_NULL(o->shallow_stat);
 640 }