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 #include "commit-graph.h"
  13
  14 unsigned int get_max_object_index(void)
  15 {
  16         return the_repository->parsed_objects->obj_hash_size;
  17 }
  18
  19 struct object *get_indexed_object(unsigned int idx)
  20 {
  21         return the_repository->parsed_objects->obj_hash[idx];
  22 }
  23
  24 static const char *object_type_strings[] = {
  25         NULL,           /* OBJ_NONE = 0 */
  26         "commit",       /* OBJ_COMMIT = 1 */
  27         "tree",         /* OBJ_TREE = 2 */
  28         "blob",         /* OBJ_BLOB = 3 */
  29         "tag",          /* OBJ_TAG = 4 */
  30 };
  31
  32 const char *type_name(unsigned int type)
  33 {
  34         if (type >= ARRAY_SIZE(object_type_strings))
  35                 return NULL;
  36         return object_type_strings[type];
  37 }
  38
  39 int type_from_string_gently(const char *str, ssize_t len, int gentle)
  40 {
  41         int i;
  42
  43         if (len < 0)
  44                 len = strlen(str);
  45
  46         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  47                 if (!strncmp(str, object_type_strings[i], len) &&
  48                     object_type_strings[i][len] == '\0')
  49                         return i;
  50
  51         if (gentle)
  52                 return -1;
  53
  54         die(_("invalid object type \"%s\""), str);
  55 }
  56
  57 /*
  58  * Return a numerical hash value between 0 and n-1 for the object with
  59  * the specified sha1.  n must be a power of 2.  Please note that the
  60  * return value is *not* consistent across computer architectures.
  61  */
  62 static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
  63 {
  64         return sha1hash(sha1) & (n - 1);
  65 }
  66
  67 /*
  68  * Insert obj into the hash table hash, which has length size (which
  69  * must be a power of 2).  On collisions, simply overflow to the next
  70  * empty bucket.
  71  */
  72 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  73 {
  74         unsigned int j = hash_obj(obj->oid.hash, size);
  75
  76         while (hash[j]) {
  77                 j++;
  78                 if (j >= size)
  79                         j = 0;
  80         }
  81         hash[j] = obj;
  82 }
  83
  84 /*
  85  * Look up the record for the given sha1 in the hash map stored in
  86  * obj_hash.  Return NULL if it was not found.
  87  */
  88 struct object *lookup_object(struct repository *r, const unsigned char *sha1)
  89 {
  90         unsigned int i, first;
  91         struct object *obj;
  92
  93         if (!r->parsed_objects->obj_hash)
  94                 return NULL;
  95
  96         first = i = hash_obj(sha1, r->parsed_objects->obj_hash_size);
  97         while ((obj = r->parsed_objects->obj_hash[i]) != NULL) {
  98                 if (hasheq(sha1, obj->oid.hash))
  99                         break;
 100                 i++;
 101                 if (i == r->parsed_objects->obj_hash_size)
 102                         i = 0;
 103         }
 104         if (obj && i != first) {
 105                 /*
 106                  * Move object to where we started to look for it so
 107                  * that we do not need to walk the hash table the next
 108                  * time we look for it.
 109                  */
 110                 SWAP(r->parsed_objects->obj_hash[i],
 111                      r->parsed_objects->obj_hash[first]);
 112         }
 113         return obj;
 114 }
 115
 116 /*
 117  * Increase the size of the hash map stored in obj_hash to the next
 118  * power of 2 (but at least 32).  Copy the existing values to the new
 119  * hash map.
 120  */
 121 static void grow_object_hash(struct repository *r)
 122 {
 123         int i;
 124         /*
 125          * Note that this size must always be power-of-2 to match hash_obj
 126          * above.
 127          */
 128         int new_hash_size = r->parsed_objects->obj_hash_size < 32 ? 32 : 2 * r->parsed_objects->obj_hash_size;
 129         struct object **new_hash;
 130
 131         new_hash = xcalloc(new_hash_size, sizeof(struct object *));
 132         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 133                 struct object *obj = r->parsed_objects->obj_hash[i];
 134
 135                 if (!obj)
 136                         continue;
 137                 insert_obj_hash(obj, new_hash, new_hash_size);
 138         }
 139         free(r->parsed_objects->obj_hash);
 140         r->parsed_objects->obj_hash = new_hash;
 141         r->parsed_objects->obj_hash_size = new_hash_size;
 142 }
 143
 144 void *create_object(struct repository *r, const unsigned char *sha1, void *o)
 145 {
 146         struct object *obj = o;
 147
 148         obj->parsed = 0;
 149         obj->flags = 0;
 150         hashcpy(obj->oid.hash, sha1);
 151
 152         if (r->parsed_objects->obj_hash_size - 1 <= r->parsed_objects->nr_objs * 2)
 153                 grow_object_hash(r);
 154
 155         insert_obj_hash(obj, r->parsed_objects->obj_hash,
 156                         r->parsed_objects->obj_hash_size);
 157         r->parsed_objects->nr_objs++;
 158         return obj;
 159 }
 160
 161 void *object_as_type(struct repository *r, struct object *obj, enum object_type type, int quiet)
 162 {
 163         if (obj->type == type)
 164                 return obj;
 165         else if (obj->type == OBJ_NONE) {
 166                 if (type == OBJ_COMMIT)
 167                         init_commit_node(r, (struct commit *) obj);
 168                 else
 169                         obj->type = type;
 170                 return obj;
 171         }
 172         else {
 173                 if (!quiet)
 174                         error(_("object %s is a %s, not a %s"),
 175                               oid_to_hex(&obj->oid),
 176                               type_name(obj->type), type_name(type));
 177                 return NULL;
 178         }
 179 }
 180
 181 struct object *lookup_unknown_object(const unsigned char *sha1)
 182 {
 183         struct object *obj = lookup_object(the_repository, sha1);
 184         if (!obj)
 185                 obj = create_object(the_repository, sha1,
 186                                     alloc_object_node(the_repository));
 187         return obj;
 188 }
 189
 190 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)
 191 {
 192         struct object *obj;
 193         *eaten_p = 0;
 194
 195         obj = NULL;
 196         if (type == OBJ_BLOB) {
 197                 struct blob *blob = lookup_blob(r, oid);
 198                 if (blob) {
 199                         if (parse_blob_buffer(blob, buffer, size))
 200                                 return NULL;
 201                         obj = &blob->object;
 202                 }
 203         } else if (type == OBJ_TREE) {
 204                 struct tree *tree = lookup_tree(r, oid);
 205                 if (tree) {
 206                         obj = &tree->object;
 207                         if (!tree->buffer)
 208                                 tree->object.parsed = 0;
 209                         if (!tree->object.parsed) {
 210                                 if (parse_tree_buffer(tree, buffer, size))
 211                                         return NULL;
 212                                 *eaten_p = 1;
 213                         }
 214                 }
 215         } else if (type == OBJ_COMMIT) {
 216                 struct commit *commit = lookup_commit(r, oid);
 217                 if (commit) {
 218                         if (parse_commit_buffer(r, commit, buffer, size, 1))
 219                                 return NULL;
 220                         if (!get_cached_commit_buffer(r, commit, NULL)) {
 221                                 set_commit_buffer(r, commit, buffer, size);
 222                                 *eaten_p = 1;
 223                         }
 224                         obj = &commit->object;
 225                 }
 226         } else if (type == OBJ_TAG) {
 227                 struct tag *tag = lookup_tag(r, oid);
 228                 if (tag) {
 229                         if (parse_tag_buffer(r, tag, buffer, size))
 230                                return NULL;
 231                         obj = &tag->object;
 232                 }
 233         } else {
 234                 warning(_("object %s has unknown type id %d"), oid_to_hex(oid), type);
 235                 obj = NULL;
 236         }
 237         return obj;
 238 }
 239
 240 struct object *parse_object_or_die(const struct object_id *oid,
 241                                    const char *name)
 242 {
 243         struct object *o = parse_object(the_repository, oid);
 244         if (o)
 245                 return o;
 246
 247         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
 248 }
 249
 250 struct object *parse_object(struct repository *r, const struct object_id *oid)
 251 {
 252         unsigned long size;
 253         enum object_type type;
 254         int eaten;
 255         const struct object_id *repl = lookup_replace_object(r, oid);
 256         void *buffer;
 257         struct object *obj;
 258
 259         obj = lookup_object(r, oid->hash);
 260         if (obj && obj->parsed)
 261                 return obj;
 262
 263         if ((obj && obj->type == OBJ_BLOB && repo_has_object_file(r, oid)) ||
 264             (!obj && repo_has_object_file(r, oid) &&
 265              oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
 266                 if (check_object_signature(repl, NULL, 0, NULL) < 0) {
 267                         error(_("hash mismatch %s"), oid_to_hex(oid));
 268                         return NULL;
 269                 }
 270                 parse_blob_buffer(lookup_blob(r, oid), NULL, 0);
 271                 return lookup_object(r, oid->hash);
 272         }
 273
 274         buffer = repo_read_object_file(r, oid, &type, &size);
 275         if (buffer) {
 276                 if (check_object_signature(repl, buffer, size, 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         return o;
 484 }
 485
 486 static void free_object_directory(struct object_directory *odb)
 487 {
 488         free(odb->path);
 489         odb_clear_loose_cache(odb);
 490         free(odb);
 491 }
 492
 493 static void free_object_directories(struct raw_object_store *o)
 494 {
 495         while (o->odb) {
 496                 struct object_directory *next;
 497
 498                 next = o->odb->next;
 499                 free_object_directory(o->odb);
 500                 o->odb = next;
 501         }
 502 }
 503
 504 void raw_object_store_clear(struct raw_object_store *o)
 505 {
 506         FREE_AND_NULL(o->alternate_db);
 507
 508         oidmap_free(o->replace_map, 1);
 509         FREE_AND_NULL(o->replace_map);
 510
 511         free_commit_graph(o->commit_graph);
 512         o->commit_graph = NULL;
 513         o->commit_graph_attempted = 0;
 514
 515         free_object_directories(o);
 516         o->odb_tail = NULL;
 517         o->loaded_alternates = 0;
 518
 519         INIT_LIST_HEAD(&o->packed_git_mru);
 520         close_object_store(o);
 521         o->packed_git = NULL;
 522 }
 523
 524 void parsed_object_pool_clear(struct parsed_object_pool *o)
 525 {
 526         /*
 527          * As objects are allocated in slabs (see alloc.c), we do
 528          * not need to free each object, but each slab instead.
 529          *
 530          * Before doing so, we need to free any additional memory
 531          * the objects may hold.
 532          */
 533         unsigned i;
 534
 535         for (i = 0; i < o->obj_hash_size; i++) {
 536                 struct object *obj = o->obj_hash[i];
 537
 538                 if (!obj)
 539                         continue;
 540
 541                 if (obj->type == OBJ_TREE)
 542                         free_tree_buffer((struct tree*)obj);
 543                 else if (obj->type == OBJ_COMMIT)
 544                         release_commit_memory(o, (struct commit*)obj);
 545                 else if (obj->type == OBJ_TAG)
 546                         release_tag_memory((struct tag*)obj);
 547         }
 548
 549         FREE_AND_NULL(o->obj_hash);
 550         o->obj_hash_size = 0;
 551
 552         free_commit_buffer_slab(o->buffer_slab);
 553         o->buffer_slab = NULL;
 554
 555         clear_alloc_state(o->blob_state);
 556         clear_alloc_state(o->tree_state);
 557         clear_alloc_state(o->commit_state);
 558         clear_alloc_state(o->tag_state);
 559         clear_alloc_state(o->object_state);
 560         stat_validity_clear(o->shallow_stat);
 561         FREE_AND_NULL(o->blob_state);
 562         FREE_AND_NULL(o->tree_state);
 563         FREE_AND_NULL(o->commit_state);
 564         FREE_AND_NULL(o->tag_state);
 565         FREE_AND_NULL(o->object_state);
 566         FREE_AND_NULL(o->shallow_stat);
 567 }