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                         ((struct commit *)obj)->index = alloc_commit_index(r);
 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 unsigned char *sha1)
 181 {
 182         struct object *obj = lookup_object(the_repository, sha1);
 183         if (!obj)
 184                 obj = create_object(the_repository, sha1,
 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->hash);
 259         if (obj && obj->parsed)
 260                 return obj;
 261
 262         if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
 263             (!obj && has_object_file(oid) &&
 264              oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
 265                 if (check_object_signature(repl, NULL, 0, NULL) < 0) {
 266                         error(_("sha1 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->hash);
 271         }
 272
 273         buffer = read_object_file(oid, &type, &size);
 274         if (buffer) {
 275                 if (check_object_signature(repl, buffer, size, type_name(type)) < 0) {
 276                         free(buffer);
 277                         error(_("sha1 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 /*
 311  * A zero-length string to which object_array_entry::name can be
 312  * initialized without requiring a malloc/free.
 313  */
 314 static char object_array_slopbuf[1];
 315
 316 void add_object_array_with_path(struct object *obj, const char *name,
 317                                 struct object_array *array,
 318                                 unsigned mode, const char *path)
 319 {
 320         unsigned nr = array->nr;
 321         unsigned alloc = array->alloc;
 322         struct object_array_entry *objects = array->objects;
 323         struct object_array_entry *entry;
 324
 325         if (nr >= alloc) {
 326                 alloc = (alloc + 32) * 2;
 327                 REALLOC_ARRAY(objects, alloc);
 328                 array->alloc = alloc;
 329                 array->objects = objects;
 330         }
 331         entry = &objects[nr];
 332         entry->item = obj;
 333         if (!name)
 334                 entry->name = NULL;
 335         else if (!*name)
 336                 /* Use our own empty string instead of allocating one: */
 337                 entry->name = object_array_slopbuf;
 338         else
 339                 entry->name = xstrdup(name);
 340         entry->mode = mode;
 341         if (path)
 342                 entry->path = xstrdup(path);
 343         else
 344                 entry->path = NULL;
 345         array->nr = ++nr;
 346 }
 347
 348 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 349 {
 350         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 351 }
 352
 353 /*
 354  * Free all memory associated with an entry; the result is
 355  * in an unspecified state and should not be examined.
 356  */
 357 static void object_array_release_entry(struct object_array_entry *ent)
 358 {
 359         if (ent->name != object_array_slopbuf)
 360                 free(ent->name);
 361         free(ent->path);
 362 }
 363
 364 struct object *object_array_pop(struct object_array *array)
 365 {
 366         struct object *ret;
 367
 368         if (!array->nr)
 369                 return NULL;
 370
 371         ret = array->objects[array->nr - 1].item;
 372         object_array_release_entry(&array->objects[array->nr - 1]);
 373         array->nr--;
 374         return ret;
 375 }
 376
 377 void object_array_filter(struct object_array *array,
 378                          object_array_each_func_t want, void *cb_data)
 379 {
 380         unsigned nr = array->nr, src, dst;
 381         struct object_array_entry *objects = array->objects;
 382
 383         for (src = dst = 0; src < nr; src++) {
 384                 if (want(&objects[src], cb_data)) {
 385                         if (src != dst)
 386                                 objects[dst] = objects[src];
 387                         dst++;
 388                 } else {
 389                         object_array_release_entry(&objects[src]);
 390                 }
 391         }
 392         array->nr = dst;
 393 }
 394
 395 void object_array_clear(struct object_array *array)
 396 {
 397         int i;
 398         for (i = 0; i < array->nr; i++)
 399                 object_array_release_entry(&array->objects[i]);
 400         FREE_AND_NULL(array->objects);
 401         array->nr = array->alloc = 0;
 402 }
 403
 404 /*
 405  * Return true iff array already contains an entry with name.
 406  */
 407 static int contains_name(struct object_array *array, const char *name)
 408 {
 409         unsigned nr = array->nr, i;
 410         struct object_array_entry *object = array->objects;
 411
 412         for (i = 0; i < nr; i++, object++)
 413                 if (!strcmp(object->name, name))
 414                         return 1;
 415         return 0;
 416 }
 417
 418 void object_array_remove_duplicates(struct object_array *array)
 419 {
 420         unsigned nr = array->nr, src;
 421         struct object_array_entry *objects = array->objects;
 422
 423         array->nr = 0;
 424         for (src = 0; src < nr; src++) {
 425                 if (!contains_name(array, objects[src].name)) {
 426                         if (src != array->nr)
 427                                 objects[array->nr] = objects[src];
 428                         array->nr++;
 429                 } else {
 430                         object_array_release_entry(&objects[src]);
 431                 }
 432         }
 433 }
 434
 435 void clear_object_flags(unsigned flags)
 436 {
 437         int i;
 438
 439         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 440                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 441                 if (obj)
 442                         obj->flags &= ~flags;
 443         }
 444 }
 445
 446 void clear_commit_marks_all(unsigned int 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 && obj->type == OBJ_COMMIT)
 453                         obj->flags &= ~flags;
 454         }
 455 }
 456
 457 struct parsed_object_pool *parsed_object_pool_new(void)
 458 {
 459         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 460         memset(o, 0, sizeof(*o));
 461
 462         o->blob_state = allocate_alloc_state();
 463         o->tree_state = allocate_alloc_state();
 464         o->commit_state = allocate_alloc_state();
 465         o->tag_state = allocate_alloc_state();
 466         o->object_state = allocate_alloc_state();
 467
 468         o->is_shallow = -1;
 469         o->shallow_stat = xcalloc(1, sizeof(*o->shallow_stat));
 470
 471         o->buffer_slab = allocate_commit_buffer_slab();
 472
 473         return o;
 474 }
 475
 476 struct raw_object_store *raw_object_store_new(void)
 477 {
 478         struct raw_object_store *o = xmalloc(sizeof(*o));
 479
 480         memset(o, 0, sizeof(*o));
 481         INIT_LIST_HEAD(&o->packed_git_mru);
 482         return o;
 483 }
 484
 485 static void free_alt_odb(struct alternate_object_database *alt)
 486 {
 487         strbuf_release(&alt->scratch);
 488         oid_array_clear(&alt->loose_objects_cache);
 489         free(alt);
 490 }
 491
 492 static void free_alt_odbs(struct raw_object_store *o)
 493 {
 494         while (o->alt_odb_list) {
 495                 struct alternate_object_database *next;
 496
 497                 next = o->alt_odb_list->next;
 498                 free_alt_odb(o->alt_odb_list);
 499                 o->alt_odb_list = next;
 500         }
 501 }
 502
 503 void raw_object_store_clear(struct raw_object_store *o)
 504 {
 505         FREE_AND_NULL(o->objectdir);
 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_alt_odbs(o);
 516         o->alt_odb_tail = NULL;
 517
 518         INIT_LIST_HEAD(&o->packed_git_mru);
 519         close_all_packs(o);
 520         o->packed_git = NULL;
 521 }
 522
 523 void parsed_object_pool_clear(struct parsed_object_pool *o)
 524 {
 525         /*
 526          * As objects are allocated in slabs (see alloc.c), we do
 527          * not need to free each object, but each slab instead.
 528          *
 529          * Before doing so, we need to free any additional memory
 530          * the objects may hold.
 531          */
 532         unsigned i;
 533
 534         for (i = 0; i < o->obj_hash_size; i++) {
 535                 struct object *obj = o->obj_hash[i];
 536
 537                 if (!obj)
 538                         continue;
 539
 540                 if (obj->type == OBJ_TREE)
 541                         free_tree_buffer((struct tree*)obj);
 542                 else if (obj->type == OBJ_COMMIT)
 543                         release_commit_memory((struct commit*)obj);
 544                 else if (obj->type == OBJ_TAG)
 545                         release_tag_memory((struct tag*)obj);
 546         }
 547
 548         FREE_AND_NULL(o->obj_hash);
 549         o->obj_hash_size = 0;
 550
 551         free_commit_buffer_slab(o->buffer_slab);
 552         o->buffer_slab = NULL;
 553
 554         clear_alloc_state(o->blob_state);
 555         clear_alloc_state(o->tree_state);
 556         clear_alloc_state(o->commit_state);
 557         clear_alloc_state(o->tag_state);
 558         clear_alloc_state(o->object_state);
 559         FREE_AND_NULL(o->blob_state);
 560         FREE_AND_NULL(o->tree_state);
 561         FREE_AND_NULL(o->commit_state);
 562         FREE_AND_NULL(o->tag_state);
 563         FREE_AND_NULL(o->object_state);
 564 }