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         new_hash = xcalloc(new_hash_size, sizeof(struct object *));
 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 repository *r, 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(r, (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(const struct object_id *oid)
 181 {
 182         struct object *obj = lookup_object(the_repository, oid);
 183         if (!obj)
 184                 obj = create_object(the_repository, oid,
 185                                     alloc_object_node(the_repository));
 186         return obj;
 187 }
 188
 189 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)
 190 {
 191         struct object *obj;
 192         *eaten_p = 0;
 193
 194         obj = NULL;
 195         if (type == OBJ_BLOB) {
 196                 struct blob *blob = lookup_blob(r, oid);
 197                 if (blob) {
 198                         if (parse_blob_buffer(blob, buffer, size))
 199                                 return NULL;
 200                         obj = &blob->object;
 201                 }
 202         } else if (type == OBJ_TREE) {
 203                 struct tree *tree = lookup_tree(r, oid);
 204                 if (tree) {
 205                         obj = &tree->object;
 206                         if (!tree->buffer)
 207                                 tree->object.parsed = 0;
 208                         if (!tree->object.parsed) {
 209                                 if (parse_tree_buffer(tree, buffer, size))
 210                                         return NULL;
 211                                 *eaten_p = 1;
 212                         }
 213                 }
 214         } else if (type == OBJ_COMMIT) {
 215                 struct commit *commit = lookup_commit(r, oid);
 216                 if (commit) {
 217                         if (parse_commit_buffer(r, commit, buffer, size, 1))
 218                                 return NULL;
 219                         if (!get_cached_commit_buffer(r, commit, NULL)) {
 220                                 set_commit_buffer(r, commit, buffer, size);
 221                                 *eaten_p = 1;
 222                         }
 223                         obj = &commit->object;
 224                 }
 225         } else if (type == OBJ_TAG) {
 226                 struct tag *tag = lookup_tag(r, oid);
 227                 if (tag) {
 228                         if (parse_tag_buffer(r, tag, buffer, size))
 229                                return NULL;
 230                         obj = &tag->object;
 231                 }
 232         } else {
 233                 warning(_("object %s has unknown type id %d"), oid_to_hex(oid), type);
 234                 obj = NULL;
 235         }
 236         return obj;
 237 }
 238
 239 struct object *parse_object_or_die(const struct object_id *oid,
 240                                    const char *name)
 241 {
 242         struct object *o = parse_object(the_repository, oid);
 243         if (o)
 244                 return o;
 245
 246         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
 247 }
 248
 249 struct object *parse_object(struct repository *r, const struct object_id *oid)
 250 {
 251         unsigned long size;
 252         enum object_type type;
 253         int eaten;
 254         const struct object_id *repl = lookup_replace_object(r, oid);
 255         void *buffer;
 256         struct object *obj;
 257
 258         obj = lookup_object(r, oid);
 259         if (obj && obj->parsed)
 260                 return obj;
 261
 262         if ((obj && obj->type == OBJ_BLOB && repo_has_object_file(r, oid)) ||
 263             (!obj && repo_has_object_file(r, oid) &&
 264              oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
 265                 if (check_object_signature(r, repl, NULL, 0, NULL) < 0) {
 266                         error(_("hash mismatch %s"), oid_to_hex(oid));
 267                         return NULL;
 268                 }
 269                 parse_blob_buffer(lookup_blob(r, oid), NULL, 0);
 270                 return lookup_object(r, oid);
 271         }
 272
 273         buffer = repo_read_object_file(r, oid, &type, &size);
 274         if (buffer) {
 275                 if (check_object_signature(r, repl, buffer, size,
 276                                            type_name(type)) < 0) {
 277                         free(buffer);
 278                         error(_("hash mismatch %s"), oid_to_hex(repl));
 279                         return NULL;
 280                 }
 281
 282                 obj = parse_object_buffer(r, oid, type, size,
 283                                           buffer, &eaten);
 284                 if (!eaten)
 285                         free(buffer);
 286                 return obj;
 287         }
 288         return NULL;
 289 }
 290
 291 struct object_list *object_list_insert(struct object *item,
 292                                        struct object_list **list_p)
 293 {
 294         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 295         new_list->item = item;
 296         new_list->next = *list_p;
 297         *list_p = new_list;
 298         return new_list;
 299 }
 300
 301 int object_list_contains(struct object_list *list, struct object *obj)
 302 {
 303         while (list) {
 304                 if (list->item == obj)
 305                         return 1;
 306                 list = list->next;
 307         }
 308         return 0;
 309 }
 310
 311 /*
 312  * A zero-length string to which object_array_entry::name can be
 313  * initialized without requiring a malloc/free.
 314  */
 315 static char object_array_slopbuf[1];
 316
 317 void add_object_array_with_path(struct object *obj, const char *name,
 318                                 struct object_array *array,
 319                                 unsigned mode, const char *path)
 320 {
 321         unsigned nr = array->nr;
 322         unsigned alloc = array->alloc;
 323         struct object_array_entry *objects = array->objects;
 324         struct object_array_entry *entry;
 325
 326         if (nr >= alloc) {
 327                 alloc = (alloc + 32) * 2;
 328                 REALLOC_ARRAY(objects, alloc);
 329                 array->alloc = alloc;
 330                 array->objects = objects;
 331         }
 332         entry = &objects[nr];
 333         entry->item = obj;
 334         if (!name)
 335                 entry->name = NULL;
 336         else if (!*name)
 337                 /* Use our own empty string instead of allocating one: */
 338                 entry->name = object_array_slopbuf;
 339         else
 340                 entry->name = xstrdup(name);
 341         entry->mode = mode;
 342         if (path)
 343                 entry->path = xstrdup(path);
 344         else
 345                 entry->path = NULL;
 346         array->nr = ++nr;
 347 }
 348
 349 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 350 {
 351         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 352 }
 353
 354 /*
 355  * Free all memory associated with an entry; the result is
 356  * in an unspecified state and should not be examined.
 357  */
 358 static void object_array_release_entry(struct object_array_entry *ent)
 359 {
 360         if (ent->name != object_array_slopbuf)
 361                 free(ent->name);
 362         free(ent->path);
 363 }
 364
 365 struct object *object_array_pop(struct object_array *array)
 366 {
 367         struct object *ret;
 368
 369         if (!array->nr)
 370                 return NULL;
 371
 372         ret = array->objects[array->nr - 1].item;
 373         object_array_release_entry(&array->objects[array->nr - 1]);
 374         array->nr--;
 375         return ret;
 376 }
 377
 378 void object_array_filter(struct object_array *array,
 379                          object_array_each_func_t want, void *cb_data)
 380 {
 381         unsigned nr = array->nr, src, dst;
 382         struct object_array_entry *objects = array->objects;
 383
 384         for (src = dst = 0; src < nr; src++) {
 385                 if (want(&objects[src], cb_data)) {
 386                         if (src != dst)
 387                                 objects[dst] = objects[src];
 388                         dst++;
 389                 } else {
 390                         object_array_release_entry(&objects[src]);
 391                 }
 392         }
 393         array->nr = dst;
 394 }
 395
 396 void object_array_clear(struct object_array *array)
 397 {
 398         int i;
 399         for (i = 0; i < array->nr; i++)
 400                 object_array_release_entry(&array->objects[i]);
 401         FREE_AND_NULL(array->objects);
 402         array->nr = array->alloc = 0;
 403 }
 404
 405 /*
 406  * Return true iff array already contains an entry with name.
 407  */
 408 static int contains_name(struct object_array *array, const char *name)
 409 {
 410         unsigned nr = array->nr, i;
 411         struct object_array_entry *object = array->objects;
 412
 413         for (i = 0; i < nr; i++, object++)
 414                 if (!strcmp(object->name, name))
 415                         return 1;
 416         return 0;
 417 }
 418
 419 void object_array_remove_duplicates(struct object_array *array)
 420 {
 421         unsigned nr = array->nr, src;
 422         struct object_array_entry *objects = array->objects;
 423
 424         array->nr = 0;
 425         for (src = 0; src < nr; src++) {
 426                 if (!contains_name(array, objects[src].name)) {
 427                         if (src != array->nr)
 428                                 objects[array->nr] = objects[src];
 429                         array->nr++;
 430                 } else {
 431                         object_array_release_entry(&objects[src]);
 432                 }
 433         }
 434 }
 435
 436 void clear_object_flags(unsigned flags)
 437 {
 438         int i;
 439
 440         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 441                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 442                 if (obj)
 443                         obj->flags &= ~flags;
 444         }
 445 }
 446
 447 void clear_commit_marks_all(unsigned int flags)
 448 {
 449         int i;
 450
 451         for (i = 0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 452                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 453                 if (obj && obj->type == OBJ_COMMIT)
 454                         obj->flags &= ~flags;
 455         }
 456 }
 457
 458 struct parsed_object_pool *parsed_object_pool_new(void)
 459 {
 460         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 461         memset(o, 0, sizeof(*o));
 462
 463         o->blob_state = allocate_alloc_state();
 464         o->tree_state = allocate_alloc_state();
 465         o->commit_state = allocate_alloc_state();
 466         o->tag_state = allocate_alloc_state();
 467         o->object_state = allocate_alloc_state();
 468
 469         o->is_shallow = -1;
 470         o->shallow_stat = xcalloc(1, sizeof(*o->shallow_stat));
 471
 472         o->buffer_slab = allocate_commit_buffer_slab();
 473
 474         return o;
 475 }
 476
 477 struct raw_object_store *raw_object_store_new(void)
 478 {
 479         struct raw_object_store *o = xmalloc(sizeof(*o));
 480
 481         memset(o, 0, sizeof(*o));
 482         INIT_LIST_HEAD(&o->packed_git_mru);
 483         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
 484         pthread_mutex_init(&o->replace_mutex, NULL);
 485         return o;
 486 }
 487
 488 static void free_object_directory(struct object_directory *odb)
 489 {
 490         free(odb->path);
 491         odb_clear_loose_cache(odb);
 492         free(odb);
 493 }
 494
 495 static void free_object_directories(struct raw_object_store *o)
 496 {
 497         while (o->odb) {
 498                 struct object_directory *next;
 499
 500                 next = o->odb->next;
 501                 free_object_directory(o->odb);
 502                 o->odb = next;
 503         }
 504 }
 505
 506 void raw_object_store_clear(struct raw_object_store *o)
 507 {
 508         FREE_AND_NULL(o->alternate_db);
 509
 510         oidmap_free(o->replace_map, 1);
 511         FREE_AND_NULL(o->replace_map);
 512         pthread_mutex_destroy(&o->replace_mutex);
 513
 514         free_commit_graph(o->commit_graph);
 515         o->commit_graph = NULL;
 516         o->commit_graph_attempted = 0;
 517
 518         free_object_directories(o);
 519         o->odb_tail = NULL;
 520         o->loaded_alternates = 0;
 521
 522         INIT_LIST_HEAD(&o->packed_git_mru);
 523         close_object_store(o);
 524         o->packed_git = NULL;
 525
 526         hashmap_free(&o->pack_map);
 527 }
 528
 529 void parsed_object_pool_clear(struct parsed_object_pool *o)
 530 {
 531         /*
 532          * As objects are allocated in slabs (see alloc.c), we do
 533          * not need to free each object, but each slab instead.
 534          *
 535          * Before doing so, we need to free any additional memory
 536          * the objects may hold.
 537          */
 538         unsigned i;
 539
 540         for (i = 0; i < o->obj_hash_size; i++) {
 541                 struct object *obj = o->obj_hash[i];
 542
 543                 if (!obj)
 544                         continue;
 545
 546                 if (obj->type == OBJ_TREE)
 547                         free_tree_buffer((struct tree*)obj);
 548                 else if (obj->type == OBJ_COMMIT)
 549                         release_commit_memory(o, (struct commit*)obj);
 550                 else if (obj->type == OBJ_TAG)
 551                         release_tag_memory((struct tag*)obj);
 552         }
 553
 554         FREE_AND_NULL(o->obj_hash);
 555         o->obj_hash_size = 0;
 556
 557         free_commit_buffer_slab(o->buffer_slab);
 558         o->buffer_slab = NULL;
 559
 560         clear_alloc_state(o->blob_state);
 561         clear_alloc_state(o->tree_state);
 562         clear_alloc_state(o->commit_state);
 563         clear_alloc_state(o->tag_state);
 564         clear_alloc_state(o->object_state);
 565         stat_validity_clear(o->shallow_stat);
 566         FREE_AND_NULL(o->blob_state);
 567         FREE_AND_NULL(o->tree_state);
 568         FREE_AND_NULL(o->commit_state);
 569         FREE_AND_NULL(o->tag_state);
 570         FREE_AND_NULL(o->object_state);
 571         FREE_AND_NULL(o->shallow_stat);
 572 }