git.oblomov.eu Git - git/blob - 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 "object-store.h"
   9 #include "packfile.h"
  10
  11 unsigned int get_max_object_index(void)
  12 {
  13         return the_repository->parsed_objects->obj_hash_size;
  14 }
  15
  16 struct object *get_indexed_object(unsigned int idx)
  17 {
  18         return the_repository->parsed_objects->obj_hash[idx];
  19 }
  20
  21 static const char *object_type_strings[] = {
  22         NULL,           /* OBJ_NONE = 0 */
  23         "commit",       /* OBJ_COMMIT = 1 */
  24         "tree",         /* OBJ_TREE = 2 */
  25         "blob",         /* OBJ_BLOB = 3 */
  26         "tag",          /* OBJ_TAG = 4 */
  27 };
  28
  29 const char *type_name(unsigned int type)
  30 {
  31         if (type >= ARRAY_SIZE(object_type_strings))
  32                 return NULL;
  33         return object_type_strings[type];
  34 }
  35
  36 int type_from_string_gently(const char *str, ssize_t len, int gentle)
  37 {
  38         int i;
  39
  40         if (len < 0)
  41                 len = strlen(str);
  42
  43         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  44                 if (!strncmp(str, object_type_strings[i], len) &&
  45                     object_type_strings[i][len] == '\0')
  46                         return i;
  47
  48         if (gentle)
  49                 return -1;
  50
  51         die("invalid object type \"%s\"", str);
  52 }
  53
  54 /*
  55  * Return a numerical hash value between 0 and n-1 for the object with
  56  * the specified sha1.  n must be a power of 2.  Please note that the
  57  * return value is *not* consistent across computer architectures.
  58  */
  59 static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
  60 {
  61         return sha1hash(sha1) & (n - 1);
  62 }
  63
  64 /*
  65  * Insert obj into the hash table hash, which has length size (which
  66  * must be a power of 2).  On collisions, simply overflow to the next
  67  * empty bucket.
  68  */
  69 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  70 {
  71         unsigned int j = hash_obj(obj->oid.hash, size);
  72
  73         while (hash[j]) {
  74                 j++;
  75                 if (j >= size)
  76                         j = 0;
  77         }
  78         hash[j] = obj;
  79 }
  80
  81 /*
  82  * Look up the record for the given sha1 in the hash map stored in
  83  * obj_hash.  Return NULL if it was not found.
  84  */
  85 struct object *lookup_object(const unsigned char *sha1)
  86 {
  87         unsigned int i, first;
  88         struct object *obj;
  89
  90         if (!the_repository->parsed_objects->obj_hash)
  91                 return NULL;
  92
  93         first = i = hash_obj(sha1,
  94                              the_repository->parsed_objects->obj_hash_size);
  95         while ((obj = the_repository->parsed_objects->obj_hash[i]) != NULL) {
  96                 if (!hashcmp(sha1, obj->oid.hash))
  97                         break;
  98                 i++;
  99                 if (i == the_repository->parsed_objects->obj_hash_size)
 100                         i = 0;
 101         }
 102         if (obj && i != first) {
 103                 /*
 104                  * Move object to where we started to look for it so
 105                  * that we do not need to walk the hash table the next
 106                  * time we look for it.
 107                  */
 108                 SWAP(the_repository->parsed_objects->obj_hash[i],
 109                      the_repository->parsed_objects->obj_hash[first]);
 110         }
 111         return obj;
 112 }
 113
 114 /*
 115  * Increase the size of the hash map stored in obj_hash to the next
 116  * power of 2 (but at least 32).  Copy the existing values to the new
 117  * hash map.
 118  */
 119 static void grow_object_hash(void)
 120 {
 121         int i;
 122         /*
 123          * Note that this size must always be power-of-2 to match hash_obj
 124          * above.
 125          */
 126         int new_hash_size = the_repository->parsed_objects->obj_hash_size < 32 ? 32 : 2 * the_repository->parsed_objects->obj_hash_size;
 127         struct object **new_hash;
 128
 129         new_hash = xcalloc(new_hash_size, sizeof(struct object *));
 130         for (i = 0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 131                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 132                 if (!obj)
 133                         continue;
 134                 insert_obj_hash(obj, new_hash, new_hash_size);
 135         }
 136         free(the_repository->parsed_objects->obj_hash);
 137         the_repository->parsed_objects->obj_hash = new_hash;
 138         the_repository->parsed_objects->obj_hash_size = new_hash_size;
 139 }
 140
 141 void *create_object_the_repository(const unsigned char *sha1, void *o)
 142 {
 143         struct object *obj = o;
 144
 145         obj->parsed = 0;
 146         obj->flags = 0;
 147         hashcpy(obj->oid.hash, sha1);
 148
 149         if (the_repository->parsed_objects->obj_hash_size - 1 <= the_repository->parsed_objects->nr_objs * 2)
 150                 grow_object_hash();
 151
 152         insert_obj_hash(obj, the_repository->parsed_objects->obj_hash,
 153                         the_repository->parsed_objects->obj_hash_size);
 154         the_repository->parsed_objects->nr_objs++;
 155         return obj;
 156 }
 157
 158 void *object_as_type(struct object *obj, enum object_type type, int quiet)
 159 {
 160         if (obj->type == type)
 161                 return obj;
 162         else if (obj->type == OBJ_NONE) {
 163                 if (type == OBJ_COMMIT)
 164                         ((struct commit *)obj)->index = alloc_commit_index();
 165                 obj->type = type;
 166                 return obj;
 167         }
 168         else {
 169                 if (!quiet)
 170                         error("object %s is a %s, not a %s",
 171                               oid_to_hex(&obj->oid),
 172                               type_name(obj->type), type_name(type));
 173                 return NULL;
 174         }
 175 }
 176
 177 struct object *lookup_unknown_object(const unsigned char *sha1)
 178 {
 179         struct object *obj = lookup_object(sha1);
 180         if (!obj)
 181                 obj = create_object(the_repository, sha1,
 182                                     alloc_object_node());
 183         return obj;
 184 }
 185
 186 struct object *parse_object_buffer(const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
 187 {
 188         struct object *obj;
 189         *eaten_p = 0;
 190
 191         obj = NULL;
 192         if (type == OBJ_BLOB) {
 193                 struct blob *blob = lookup_blob(oid);
 194                 if (blob) {
 195                         if (parse_blob_buffer(blob, buffer, size))
 196                                 return NULL;
 197                         obj = &blob->object;
 198                 }
 199         } else if (type == OBJ_TREE) {
 200                 struct tree *tree = lookup_tree(oid);
 201                 if (tree) {
 202                         obj = &tree->object;
 203                         if (!tree->buffer)
 204                                 tree->object.parsed = 0;
 205                         if (!tree->object.parsed) {
 206                                 if (parse_tree_buffer(tree, buffer, size))
 207                                         return NULL;
 208                                 *eaten_p = 1;
 209                         }
 210                 }
 211         } else if (type == OBJ_COMMIT) {
 212                 struct commit *commit = lookup_commit(oid);
 213                 if (commit) {
 214                         if (parse_commit_buffer(commit, buffer, size))
 215                                 return NULL;
 216                         if (!get_cached_commit_buffer(commit, NULL)) {
 217                                 set_commit_buffer(commit, buffer, size);
 218                                 *eaten_p = 1;
 219                         }
 220                         obj = &commit->object;
 221                 }
 222         } else if (type == OBJ_TAG) {
 223                 struct tag *tag = lookup_tag(oid);
 224                 if (tag) {
 225                         if (parse_tag_buffer(tag, buffer, size))
 226                                return NULL;
 227                         obj = &tag->object;
 228                 }
 229         } else {
 230                 warning("object %s has unknown type id %d", oid_to_hex(oid), type);
 231                 obj = NULL;
 232         }
 233         return obj;
 234 }
 235
 236 struct object *parse_object_or_die(const struct object_id *oid,
 237                                    const char *name)
 238 {
 239         struct object *o = parse_object(oid);
 240         if (o)
 241                 return o;
 242
 243         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
 244 }
 245
 246 struct object *parse_object(const struct object_id *oid)
 247 {
 248         unsigned long size;
 249         enum object_type type;
 250         int eaten;
 251         const struct object_id *repl = lookup_replace_object(the_repository, oid);
 252         void *buffer;
 253         struct object *obj;
 254
 255         obj = lookup_object(oid->hash);
 256         if (obj && obj->parsed)
 257                 return obj;
 258
 259         if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
 260             (!obj && has_object_file(oid) &&
 261              oid_object_info(the_repository, oid, NULL) == OBJ_BLOB)) {
 262                 if (check_object_signature(repl, NULL, 0, NULL) < 0) {
 263                         error("sha1 mismatch %s", oid_to_hex(oid));
 264                         return NULL;
 265                 }
 266                 parse_blob_buffer(lookup_blob(oid), NULL, 0);
 267                 return lookup_object(oid->hash);
 268         }
 269
 270         buffer = read_object_file(oid, &type, &size);
 271         if (buffer) {
 272                 if (check_object_signature(repl, buffer, size, type_name(type)) < 0) {
 273                         free(buffer);
 274                         error("sha1 mismatch %s", oid_to_hex(repl));
 275                         return NULL;
 276                 }
 277
 278                 obj = parse_object_buffer(oid, type, size, buffer, &eaten);
 279                 if (!eaten)
 280                         free(buffer);
 281                 return obj;
 282         }
 283         return NULL;
 284 }
 285
 286 struct object_list *object_list_insert(struct object *item,
 287                                        struct object_list **list_p)
 288 {
 289         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 290         new_list->item = item;
 291         new_list->next = *list_p;
 292         *list_p = new_list;
 293         return new_list;
 294 }
 295
 296 int object_list_contains(struct object_list *list, struct object *obj)
 297 {
 298         while (list) {
 299                 if (list->item == obj)
 300                         return 1;
 301                 list = list->next;
 302         }
 303         return 0;
 304 }
 305
 306 /*
 307  * A zero-length string to which object_array_entry::name can be
 308  * initialized without requiring a malloc/free.
 309  */
 310 static char object_array_slopbuf[1];
 311
 312 void add_object_array_with_path(struct object *obj, const char *name,
 313                                 struct object_array *array,
 314                                 unsigned mode, const char *path)
 315 {
 316         unsigned nr = array->nr;
 317         unsigned alloc = array->alloc;
 318         struct object_array_entry *objects = array->objects;
 319         struct object_array_entry *entry;
 320
 321         if (nr >= alloc) {
 322                 alloc = (alloc + 32) * 2;
 323                 REALLOC_ARRAY(objects, alloc);
 324                 array->alloc = alloc;
 325                 array->objects = objects;
 326         }
 327         entry = &objects[nr];
 328         entry->item = obj;
 329         if (!name)
 330                 entry->name = NULL;
 331         else if (!*name)
 332                 /* Use our own empty string instead of allocating one: */
 333                 entry->name = object_array_slopbuf;
 334         else
 335                 entry->name = xstrdup(name);
 336         entry->mode = mode;
 337         if (path)
 338                 entry->path = xstrdup(path);
 339         else
 340                 entry->path = NULL;
 341         array->nr = ++nr;
 342 }
 343
 344 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 345 {
 346         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 347 }
 348
 349 /*
 350  * Free all memory associated with an entry; the result is
 351  * in an unspecified state and should not be examined.
 352  */
 353 static void object_array_release_entry(struct object_array_entry *ent)
 354 {
 355         if (ent->name != object_array_slopbuf)
 356                 free(ent->name);
 357         free(ent->path);
 358 }
 359
 360 struct object *object_array_pop(struct object_array *array)
 361 {
 362         struct object *ret;
 363
 364         if (!array->nr)
 365                 return NULL;
 366
 367         ret = array->objects[array->nr - 1].item;
 368         object_array_release_entry(&array->objects[array->nr - 1]);
 369         array->nr--;
 370         return ret;
 371 }
 372
 373 void object_array_filter(struct object_array *array,
 374                          object_array_each_func_t want, void *cb_data)
 375 {
 376         unsigned nr = array->nr, src, dst;
 377         struct object_array_entry *objects = array->objects;
 378
 379         for (src = dst = 0; src < nr; src++) {
 380                 if (want(&objects[src], cb_data)) {
 381                         if (src != dst)
 382                                 objects[dst] = objects[src];
 383                         dst++;
 384                 } else {
 385                         object_array_release_entry(&objects[src]);
 386                 }
 387         }
 388         array->nr = dst;
 389 }
 390
 391 void object_array_clear(struct object_array *array)
 392 {
 393         int i;
 394         for (i = 0; i < array->nr; i++)
 395                 object_array_release_entry(&array->objects[i]);
 396         FREE_AND_NULL(array->objects);
 397         array->nr = array->alloc = 0;
 398 }
 399
 400 /*
 401  * Return true iff array already contains an entry with name.
 402  */
 403 static int contains_name(struct object_array *array, const char *name)
 404 {
 405         unsigned nr = array->nr, i;
 406         struct object_array_entry *object = array->objects;
 407
 408         for (i = 0; i < nr; i++, object++)
 409                 if (!strcmp(object->name, name))
 410                         return 1;
 411         return 0;
 412 }
 413
 414 void object_array_remove_duplicates(struct object_array *array)
 415 {
 416         unsigned nr = array->nr, src;
 417         struct object_array_entry *objects = array->objects;
 418
 419         array->nr = 0;
 420         for (src = 0; src < nr; src++) {
 421                 if (!contains_name(array, objects[src].name)) {
 422                         if (src != array->nr)
 423                                 objects[array->nr] = objects[src];
 424                         array->nr++;
 425                 } else {
 426                         object_array_release_entry(&objects[src]);
 427                 }
 428         }
 429 }
 430
 431 void clear_object_flags(unsigned flags)
 432 {
 433         int i;
 434
 435         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 436                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 437                 if (obj)
 438                         obj->flags &= ~flags;
 439         }
 440 }
 441
 442 void clear_commit_marks_all(unsigned int flags)
 443 {
 444         int i;
 445
 446         for (i = 0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 447                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 448                 if (obj && obj->type == OBJ_COMMIT)
 449                         obj->flags &= ~flags;
 450         }
 451 }
 452
 453 struct parsed_object_pool *parsed_object_pool_new(void)
 454 {
 455         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 456         memset(o, 0, sizeof(*o));
 457         return o;
 458 }
 459
 460 struct raw_object_store *raw_object_store_new(void)
 461 {
 462         struct raw_object_store *o = xmalloc(sizeof(*o));
 463
 464         memset(o, 0, sizeof(*o));
 465         INIT_LIST_HEAD(&o->packed_git_mru);
 466         return o;
 467 }
 468
 469 static void free_alt_odb(struct alternate_object_database *alt)
 470 {
 471         strbuf_release(&alt->scratch);
 472         oid_array_clear(&alt->loose_objects_cache);
 473         free(alt);
 474 }
 475
 476 static void free_alt_odbs(struct raw_object_store *o)
 477 {
 478         while (o->alt_odb_list) {
 479                 struct alternate_object_database *next;
 480
 481                 next = o->alt_odb_list->next;
 482                 free_alt_odb(o->alt_odb_list);
 483                 o->alt_odb_list = next;
 484         }
 485 }
 486
 487 void raw_object_store_clear(struct raw_object_store *o)
 488 {
 489         FREE_AND_NULL(o->objectdir);
 490         FREE_AND_NULL(o->alternate_db);
 491
 492         free_alt_odbs(o);
 493         o->alt_odb_tail = NULL;
 494
 495         INIT_LIST_HEAD(&o->packed_git_mru);
 496         close_all_packs(o);
 497         o->packed_git = NULL;
 498 }
 499
 500 void parsed_object_pool_clear(struct parsed_object_pool *o)
 501 {
 502         /*
 503          * TOOD free objects in o->obj_hash.
 504          *
 505          * As objects are allocated in slabs (see alloc.c), we do
 506          * not need to free each object, but each slab instead.
 507          */
 508 }