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 "object-store.h"
  11 #include "packfile.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 unsigned char *sha1, unsigned int n)
  62 {
  63         return sha1hash(sha1) & (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.hash, 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 unsigned char *sha1)
  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(sha1, r->parsed_objects->obj_hash_size);
  96         while ((obj = r->parsed_objects->obj_hash[i]) != NULL) {
  97                 if (!hashcmp(sha1, obj->oid.hash))
  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 unsigned char *sha1, void *o)
 144 {
 145         struct object *obj = o;
 146
 147         obj->parsed = 0;
 148         obj->flags = 0;
 149         hashcpy(obj->oid.hash, sha1);
 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                         ((struct commit *)obj)->index = alloc_commit_index(r);
 167                 obj->type = type;
 168                 return obj;
 169         }
 170         else {
 171                 if (!quiet)
 172                         error("object %s is a %s, not a %s",
 173                               oid_to_hex(&obj->oid),
 174                               type_name(obj->type), type_name(type));
 175                 return NULL;
 176         }
 177 }
 178
 179 struct object *lookup_unknown_object(const unsigned char *sha1)
 180 {
 181         struct object *obj = lookup_object(the_repository, sha1);
 182         if (!obj)
 183                 obj = create_object(the_repository, sha1,
 184                                     alloc_object_node(the_repository));
 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->hash);
 258         if (obj && obj->parsed)
 259                 return obj;
 260
 261         if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
 262             (!obj && has_object_file(oid) &&
 263              oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
 264                 if (check_object_signature(repl, NULL, 0, NULL) < 0) {
 265                         error("sha1 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->hash);
 270         }
 271
 272         buffer = read_object_file(oid, &type, &size);
 273         if (buffer) {
 274                 if (check_object_signature(repl, buffer, size, type_name(type)) < 0) {
 275                         free(buffer);
 276                         error("sha1 mismatch %s", oid_to_hex(repl));
 277                         return NULL;
 278                 }
 279
 280                 obj = parse_object_buffer(r, oid, type, size,
 281                                           buffer, &eaten);
 282                 if (!eaten)
 283                         free(buffer);
 284                 return obj;
 285         }
 286         return NULL;
 287 }
 288
 289 struct object_list *object_list_insert(struct object *item,
 290                                        struct object_list **list_p)
 291 {
 292         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 293         new_list->item = item;
 294         new_list->next = *list_p;
 295         *list_p = new_list;
 296         return new_list;
 297 }
 298
 299 int object_list_contains(struct object_list *list, struct object *obj)
 300 {
 301         while (list) {
 302                 if (list->item == obj)
 303                         return 1;
 304                 list = list->next;
 305         }
 306         return 0;
 307 }
 308
 309 /*
 310  * A zero-length string to which object_array_entry::name can be
 311  * initialized without requiring a malloc/free.
 312  */
 313 static char object_array_slopbuf[1];
 314
 315 void add_object_array_with_path(struct object *obj, const char *name,
 316                                 struct object_array *array,
 317                                 unsigned mode, const char *path)
 318 {
 319         unsigned nr = array->nr;
 320         unsigned alloc = array->alloc;
 321         struct object_array_entry *objects = array->objects;
 322         struct object_array_entry *entry;
 323
 324         if (nr >= alloc) {
 325                 alloc = (alloc + 32) * 2;
 326                 REALLOC_ARRAY(objects, alloc);
 327                 array->alloc = alloc;
 328                 array->objects = objects;
 329         }
 330         entry = &objects[nr];
 331         entry->item = obj;
 332         if (!name)
 333                 entry->name = NULL;
 334         else if (!*name)
 335                 /* Use our own empty string instead of allocating one: */
 336                 entry->name = object_array_slopbuf;
 337         else
 338                 entry->name = xstrdup(name);
 339         entry->mode = mode;
 340         if (path)
 341                 entry->path = xstrdup(path);
 342         else
 343                 entry->path = NULL;
 344         array->nr = ++nr;
 345 }
 346
 347 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 348 {
 349         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 350 }
 351
 352 /*
 353  * Free all memory associated with an entry; the result is
 354  * in an unspecified state and should not be examined.
 355  */
 356 static void object_array_release_entry(struct object_array_entry *ent)
 357 {
 358         if (ent->name != object_array_slopbuf)
 359                 free(ent->name);
 360         free(ent->path);
 361 }
 362
 363 struct object *object_array_pop(struct object_array *array)
 364 {
 365         struct object *ret;
 366
 367         if (!array->nr)
 368                 return NULL;
 369
 370         ret = array->objects[array->nr - 1].item;
 371         object_array_release_entry(&array->objects[array->nr - 1]);
 372         array->nr--;
 373         return ret;
 374 }
 375
 376 void object_array_filter(struct object_array *array,
 377                          object_array_each_func_t want, void *cb_data)
 378 {
 379         unsigned nr = array->nr, src, dst;
 380         struct object_array_entry *objects = array->objects;
 381
 382         for (src = dst = 0; src < nr; src++) {
 383                 if (want(&objects[src], cb_data)) {
 384                         if (src != dst)
 385                                 objects[dst] = objects[src];
 386                         dst++;
 387                 } else {
 388                         object_array_release_entry(&objects[src]);
 389                 }
 390         }
 391         array->nr = dst;
 392 }
 393
 394 void object_array_clear(struct object_array *array)
 395 {
 396         int i;
 397         for (i = 0; i < array->nr; i++)
 398                 object_array_release_entry(&array->objects[i]);
 399         FREE_AND_NULL(array->objects);
 400         array->nr = array->alloc = 0;
 401 }
 402
 403 /*
 404  * Return true iff array already contains an entry with name.
 405  */
 406 static int contains_name(struct object_array *array, const char *name)
 407 {
 408         unsigned nr = array->nr, i;
 409         struct object_array_entry *object = array->objects;
 410
 411         for (i = 0; i < nr; i++, object++)
 412                 if (!strcmp(object->name, name))
 413                         return 1;
 414         return 0;
 415 }
 416
 417 void object_array_remove_duplicates(struct object_array *array)
 418 {
 419         unsigned nr = array->nr, src;
 420         struct object_array_entry *objects = array->objects;
 421
 422         array->nr = 0;
 423         for (src = 0; src < nr; src++) {
 424                 if (!contains_name(array, objects[src].name)) {
 425                         if (src != array->nr)
 426                                 objects[array->nr] = objects[src];
 427                         array->nr++;
 428                 } else {
 429                         object_array_release_entry(&objects[src]);
 430                 }
 431         }
 432 }
 433
 434 void clear_object_flags(unsigned flags)
 435 {
 436         int i;
 437
 438         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 439                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 440                 if (obj)
 441                         obj->flags &= ~flags;
 442         }
 443 }
 444
 445 void clear_commit_marks_all(unsigned int flags)
 446 {
 447         int i;
 448
 449         for (i = 0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 450                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 451                 if (obj && obj->type == OBJ_COMMIT)
 452                         obj->flags &= ~flags;
 453         }
 454 }
 455
 456 struct parsed_object_pool *parsed_object_pool_new(void)
 457 {
 458         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 459         memset(o, 0, sizeof(*o));
 460
 461         o->blob_state = allocate_alloc_state();
 462         o->tree_state = allocate_alloc_state();
 463         o->commit_state = allocate_alloc_state();
 464         o->tag_state = allocate_alloc_state();
 465         o->object_state = allocate_alloc_state();
 466
 467         o->is_shallow = -1;
 468         o->shallow_stat = xcalloc(1, sizeof(*o->shallow_stat));
 469
 470         o->buffer_slab = allocate_commit_buffer_slab();
 471
 472         return o;
 473 }
 474
 475 struct raw_object_store *raw_object_store_new(void)
 476 {
 477         struct raw_object_store *o = xmalloc(sizeof(*o));
 478
 479         memset(o, 0, sizeof(*o));
 480         INIT_LIST_HEAD(&o->packed_git_mru);
 481         return o;
 482 }
 483
 484 static void free_alt_odb(struct alternate_object_database *alt)
 485 {
 486         strbuf_release(&alt->scratch);
 487         oid_array_clear(&alt->loose_objects_cache);
 488         free(alt);
 489 }
 490
 491 static void free_alt_odbs(struct raw_object_store *o)
 492 {
 493         while (o->alt_odb_list) {
 494                 struct alternate_object_database *next;
 495
 496                 next = o->alt_odb_list->next;
 497                 free_alt_odb(o->alt_odb_list);
 498                 o->alt_odb_list = next;
 499         }
 500 }
 501
 502 void raw_object_store_clear(struct raw_object_store *o)
 503 {
 504         FREE_AND_NULL(o->objectdir);
 505         FREE_AND_NULL(o->alternate_db);
 506
 507         oidmap_free(o->replace_map, 1);
 508         FREE_AND_NULL(o->replace_map);
 509
 510         free_alt_odbs(o);
 511         o->alt_odb_tail = NULL;
 512
 513         INIT_LIST_HEAD(&o->packed_git_mru);
 514         close_all_packs(o);
 515         o->packed_git = NULL;
 516 }
 517
 518 void parsed_object_pool_clear(struct parsed_object_pool *o)
 519 {
 520         /*
 521          * As objects are allocated in slabs (see alloc.c), we do
 522          * not need to free each object, but each slab instead.
 523          *
 524          * Before doing so, we need to free any additional memory
 525          * the objects may hold.
 526          */
 527         unsigned i;
 528
 529         for (i = 0; i < o->obj_hash_size; i++) {
 530                 struct object *obj = o->obj_hash[i];
 531
 532                 if (!obj)
 533                         continue;
 534
 535                 if (obj->type == OBJ_TREE)
 536                         free_tree_buffer((struct tree*)obj);
 537                 else if (obj->type == OBJ_COMMIT)
 538                         release_commit_memory((struct commit*)obj);
 539                 else if (obj->type == OBJ_TAG)
 540                         release_tag_memory((struct tag*)obj);
 541         }
 542
 543         FREE_AND_NULL(o->obj_hash);
 544         o->obj_hash_size = 0;
 545
 546         free_commit_buffer_slab(o->buffer_slab);
 547         o->buffer_slab = NULL;
 548
 549         clear_alloc_state(o->blob_state);
 550         clear_alloc_state(o->tree_state);
 551         clear_alloc_state(o->commit_state);
 552         clear_alloc_state(o->tag_state);
 553         clear_alloc_state(o->object_state);
 554         FREE_AND_NULL(o->blob_state);
 555         FREE_AND_NULL(o->tree_state);
 556         FREE_AND_NULL(o->commit_state);
 557         FREE_AND_NULL(o->tag_state);
 558         FREE_AND_NULL(o->object_state);
 559 }