object.c

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