object.c

   1 #include "cache.h"
   2 #include "object.h"
   3 #include "replace-object.h"
   4 #include "blob.h"
   5 #include "tree.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "alloc.h"
   9 #include "object-store.h"
  10 #include "packfile.h"
  11
  12 unsigned int get_max_object_index(void)
  13 {
  14         return the_repository->parsed_objects->obj_hash_size;
  15 }
  16
  17 struct object *get_indexed_object(unsigned int idx)
  18 {
  19         return the_repository->parsed_objects->obj_hash[idx];
  20 }
  21
  22 static const char *object_type_strings[] = {
  23         NULL,           /* OBJ_NONE = 0 */
  24         "commit",       /* OBJ_COMMIT = 1 */
  25         "tree",         /* OBJ_TREE = 2 */
  26         "blob",         /* OBJ_BLOB = 3 */
  27         "tag",          /* OBJ_TAG = 4 */
  28 };
  29
  30 const char *type_name(unsigned int type)
  31 {
  32         if (type >= ARRAY_SIZE(object_type_strings))
  33                 return NULL;
  34         return object_type_strings[type];
  35 }
  36
  37 int type_from_string_gently(const char *str, ssize_t len, int gentle)
  38 {
  39         int i;
  40
  41         if (len < 0)
  42                 len = strlen(str);
  43
  44         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  45                 if (!strncmp(str, object_type_strings[i], len) &&
  46                     object_type_strings[i][len] == '\0')
  47                         return i;
  48
  49         if (gentle)
  50                 return -1;
  51
  52         die("invalid object type \"%s\"", str);
  53 }
  54
  55 /*
  56  * Return a numerical hash value between 0 and n-1 for the object with
  57  * the specified sha1.  n must be a power of 2.  Please note that the
  58  * return value is *not* consistent across computer architectures.
  59  */
  60 static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
  61 {
  62         return sha1hash(sha1) & (n - 1);
  63 }
  64
  65 /*
  66  * Insert obj into the hash table hash, which has length size (which
  67  * must be a power of 2).  On collisions, simply overflow to the next
  68  * empty bucket.
  69  */
  70 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  71 {
  72         unsigned int j = hash_obj(obj->oid.hash, size);
  73
  74         while (hash[j]) {
  75                 j++;
  76                 if (j >= size)
  77                         j = 0;
  78         }
  79         hash[j] = obj;
  80 }
  81
  82 /*
  83  * Look up the record for the given sha1 in the hash map stored in
  84  * obj_hash.  Return NULL if it was not found.
  85  */
  86 struct object *lookup_object(const unsigned char *sha1)
  87 {
  88         unsigned int i, first;
  89         struct object *obj;
  90
  91         if (!the_repository->parsed_objects->obj_hash)
  92                 return NULL;
  93
  94         first = i = hash_obj(sha1,
  95                              the_repository->parsed_objects->obj_hash_size);
  96         while ((obj = the_repository->parsed_objects->obj_hash[i]) != NULL) {
  97                 if (!hashcmp(sha1, obj->oid.hash))
  98                         break;
  99                 i++;
 100                 if (i == the_repository->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(the_repository->parsed_objects->obj_hash[i],
 110                      the_repository->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 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(the_repository);
 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(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(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(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(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(oid);
 215                 if (commit) {
 216                         if (parse_commit_buffer(commit, buffer, size, 1))
 217                                 return NULL;
 218                         if (!get_cached_commit_buffer(commit, NULL)) {
 219                                 set_commit_buffer(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(oid);
 226                 if (tag) {
 227                         if (parse_tag_buffer(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(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(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(the_repository, oid);
 254         void *buffer;
 255         struct object *obj;
 256
 257         obj = lookup_object(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(the_repository, 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(oid), NULL, 0);
 269                 return lookup_object(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(oid, type, size, buffer, &eaten);
 281                 if (!eaten)
 282                         free(buffer);
 283                 return obj;
 284         }
 285         return NULL;
 286 }
 287
 288 struct object_list *object_list_insert(struct object *item,
 289                                        struct object_list **list_p)
 290 {
 291         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 292         new_list->item = item;
 293         new_list->next = *list_p;
 294         *list_p = new_list;
 295         return new_list;
 296 }
 297
 298 int object_list_contains(struct object_list *list, struct object *obj)
 299 {
 300         while (list) {
 301                 if (list->item == obj)
 302                         return 1;
 303                 list = list->next;
 304         }
 305         return 0;
 306 }
 307
 308 /*
 309  * A zero-length string to which object_array_entry::name can be
 310  * initialized without requiring a malloc/free.
 311  */
 312 static char object_array_slopbuf[1];
 313
 314 void add_object_array_with_path(struct object *obj, const char *name,
 315                                 struct object_array *array,
 316                                 unsigned mode, const char *path)
 317 {
 318         unsigned nr = array->nr;
 319         unsigned alloc = array->alloc;
 320         struct object_array_entry *objects = array->objects;
 321         struct object_array_entry *entry;
 322
 323         if (nr >= alloc) {
 324                 alloc = (alloc + 32) * 2;
 325                 REALLOC_ARRAY(objects, alloc);
 326                 array->alloc = alloc;
 327                 array->objects = objects;
 328         }
 329         entry = &objects[nr];
 330         entry->item = obj;
 331         if (!name)
 332                 entry->name = NULL;
 333         else if (!*name)
 334                 /* Use our own empty string instead of allocating one: */
 335                 entry->name = object_array_slopbuf;
 336         else
 337                 entry->name = xstrdup(name);
 338         entry->mode = mode;
 339         if (path)
 340                 entry->path = xstrdup(path);
 341         else
 342                 entry->path = NULL;
 343         array->nr = ++nr;
 344 }
 345
 346 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 347 {
 348         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 349 }
 350
 351 /*
 352  * Free all memory associated with an entry; the result is
 353  * in an unspecified state and should not be examined.
 354  */
 355 static void object_array_release_entry(struct object_array_entry *ent)
 356 {
 357         if (ent->name != object_array_slopbuf)
 358                 free(ent->name);
 359         free(ent->path);
 360 }
 361
 362 struct object *object_array_pop(struct object_array *array)
 363 {
 364         struct object *ret;
 365
 366         if (!array->nr)
 367                 return NULL;
 368
 369         ret = array->objects[array->nr - 1].item;
 370         object_array_release_entry(&array->objects[array->nr - 1]);
 371         array->nr--;
 372         return ret;
 373 }
 374
 375 void object_array_filter(struct object_array *array,
 376                          object_array_each_func_t want, void *cb_data)
 377 {
 378         unsigned nr = array->nr, src, dst;
 379         struct object_array_entry *objects = array->objects;
 380
 381         for (src = dst = 0; src < nr; src++) {
 382                 if (want(&objects[src], cb_data)) {
 383                         if (src != dst)
 384                                 objects[dst] = objects[src];
 385                         dst++;
 386                 } else {
 387                         object_array_release_entry(&objects[src]);
 388                 }
 389         }
 390         array->nr = dst;
 391 }
 392
 393 void object_array_clear(struct object_array *array)
 394 {
 395         int i;
 396         for (i = 0; i < array->nr; i++)
 397                 object_array_release_entry(&array->objects[i]);
 398         FREE_AND_NULL(array->objects);
 399         array->nr = array->alloc = 0;
 400 }
 401
 402 /*
 403  * Return true iff array already contains an entry with name.
 404  */
 405 static int contains_name(struct object_array *array, const char *name)
 406 {
 407         unsigned nr = array->nr, i;
 408         struct object_array_entry *object = array->objects;
 409
 410         for (i = 0; i < nr; i++, object++)
 411                 if (!strcmp(object->name, name))
 412                         return 1;
 413         return 0;
 414 }
 415
 416 void object_array_remove_duplicates(struct object_array *array)
 417 {
 418         unsigned nr = array->nr, src;
 419         struct object_array_entry *objects = array->objects;
 420
 421         array->nr = 0;
 422         for (src = 0; src < nr; src++) {
 423                 if (!contains_name(array, objects[src].name)) {
 424                         if (src != array->nr)
 425                                 objects[array->nr] = objects[src];
 426                         array->nr++;
 427                 } else {
 428                         object_array_release_entry(&objects[src]);
 429                 }
 430         }
 431 }
 432
 433 void clear_object_flags(unsigned flags)
 434 {
 435         int i;
 436
 437         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 438                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 439                 if (obj)
 440                         obj->flags &= ~flags;
 441         }
 442 }
 443
 444 void clear_commit_marks_all(unsigned int flags)
 445 {
 446         int i;
 447
 448         for (i = 0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 449                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 450                 if (obj && obj->type == OBJ_COMMIT)
 451                         obj->flags &= ~flags;
 452         }
 453 }
 454
 455 struct parsed_object_pool *parsed_object_pool_new(void)
 456 {
 457         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 458         memset(o, 0, sizeof(*o));
 459
 460         o->blob_state = allocate_alloc_state();
 461         o->tree_state = allocate_alloc_state();
 462         o->commit_state = allocate_alloc_state();
 463         o->tag_state = allocate_alloc_state();
 464         o->object_state = allocate_alloc_state();
 465
 466         return o;
 467 }
 468
 469 struct raw_object_store *raw_object_store_new(void)
 470 {
 471         struct raw_object_store *o = xmalloc(sizeof(*o));
 472
 473         memset(o, 0, sizeof(*o));
 474         INIT_LIST_HEAD(&o->packed_git_mru);
 475         return o;
 476 }
 477
 478 static void free_alt_odb(struct alternate_object_database *alt)
 479 {
 480         strbuf_release(&alt->scratch);
 481         oid_array_clear(&alt->loose_objects_cache);
 482         free(alt);
 483 }
 484
 485 static void free_alt_odbs(struct raw_object_store *o)
 486 {
 487         while (o->alt_odb_list) {
 488                 struct alternate_object_database *next;
 489
 490                 next = o->alt_odb_list->next;
 491                 free_alt_odb(o->alt_odb_list);
 492                 o->alt_odb_list = next;
 493         }
 494 }
 495
 496 void raw_object_store_clear(struct raw_object_store *o)
 497 {
 498         FREE_AND_NULL(o->objectdir);
 499         FREE_AND_NULL(o->alternate_db);
 500
 501         oidmap_free(o->replace_map, 1);
 502         FREE_AND_NULL(o->replace_map);
 503
 504         free_alt_odbs(o);
 505         o->alt_odb_tail = NULL;
 506
 507         INIT_LIST_HEAD(&o->packed_git_mru);
 508         close_all_packs(o);
 509         o->packed_git = NULL;
 510 }
 511
 512 void parsed_object_pool_clear(struct parsed_object_pool *o)
 513 {
 514         /*
 515          * As objects are allocated in slabs (see alloc.c), we do
 516          * not need to free each object, but each slab instead.
 517          *
 518          * Before doing so, we need to free any additional memory
 519          * the objects may hold.
 520          */
 521         unsigned i;
 522
 523         for (i = 0; i < o->obj_hash_size; i++) {
 524                 struct object *obj = o->obj_hash[i];
 525
 526                 if (!obj)
 527                         continue;
 528
 529                 if (obj->type == OBJ_TREE)
 530                         free_tree_buffer((struct tree*)obj);
 531                 else if (obj->type == OBJ_COMMIT)
 532                         release_commit_memory((struct commit*)obj);
 533                 else if (obj->type == OBJ_TAG)
 534                         release_tag_memory((struct tag*)obj);
 535         }
 536
 537         FREE_AND_NULL(o->obj_hash);
 538         o->obj_hash_size = 0;
 539
 540         clear_alloc_state(o->blob_state);
 541         clear_alloc_state(o->tree_state);
 542         clear_alloc_state(o->commit_state);
 543         clear_alloc_state(o->tag_state);
 544         clear_alloc_state(o->object_state);
 545         FREE_AND_NULL(o->blob_state);
 546         FREE_AND_NULL(o->tree_state);
 547         FREE_AND_NULL(o->commit_state);
 548         FREE_AND_NULL(o->tag_state);
 549         FREE_AND_NULL(o->object_state);
 550 }