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 #define grow_object_hash(r) grow_object_hash_##r()
 120 static void grow_object_hash_the_repository(void)
 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 = the_repository->parsed_objects->obj_hash_size < 32 ? 32 : 2 * the_repository->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 < the_repository->parsed_objects->obj_hash_size; i++) {
 132                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 133                 if (!obj)
 134                         continue;
 135                 insert_obj_hash(obj, new_hash, new_hash_size);
 136         }
 137         free(the_repository->parsed_objects->obj_hash);
 138         the_repository->parsed_objects->obj_hash = new_hash;
 139         the_repository->parsed_objects->obj_hash_size = new_hash_size;
 140 }
 141
 142 void *create_object_the_repository(const unsigned char *sha1, void *o)
 143 {
 144         struct object *obj = o;
 145
 146         obj->parsed = 0;
 147         obj->flags = 0;
 148         hashcpy(obj->oid.hash, sha1);
 149
 150         if (the_repository->parsed_objects->obj_hash_size - 1 <= the_repository->parsed_objects->nr_objs * 2)
 151                 grow_object_hash(the_repository);
 152
 153         insert_obj_hash(obj, the_repository->parsed_objects->obj_hash,
 154                         the_repository->parsed_objects->obj_hash_size);
 155         the_repository->parsed_objects->nr_objs++;
 156         return obj;
 157 }
 158
 159 void *object_as_type(struct object *obj, enum object_type type, int quiet)
 160 {
 161         if (obj->type == type)
 162                 return obj;
 163         else if (obj->type == OBJ_NONE) {
 164                 if (type == OBJ_COMMIT)
 165                         ((struct commit *)obj)->index = alloc_commit_index(the_repository);
 166                 obj->type = type;
 167                 return obj;
 168         }
 169         else {
 170                 if (!quiet)
 171                         error("object %s is a %s, not a %s",
 172                               oid_to_hex(&obj->oid),
 173                               type_name(obj->type), type_name(type));
 174                 return NULL;
 175         }
 176 }
 177
 178 struct object *lookup_unknown_object(const unsigned char *sha1)
 179 {
 180         struct object *obj = lookup_object(sha1);
 181         if (!obj)
 182                 obj = create_object(the_repository, sha1,
 183                                     alloc_object_node(the_repository));
 184         return obj;
 185 }
 186
 187 struct object *parse_object_buffer(const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
 188 {
 189         struct object *obj;
 190         *eaten_p = 0;
 191
 192         obj = NULL;
 193         if (type == OBJ_BLOB) {
 194                 struct blob *blob = lookup_blob(oid);
 195                 if (blob) {
 196                         if (parse_blob_buffer(blob, buffer, size))
 197                                 return NULL;
 198                         obj = &blob->object;
 199                 }
 200         } else if (type == OBJ_TREE) {
 201                 struct tree *tree = lookup_tree(oid);
 202                 if (tree) {
 203                         obj = &tree->object;
 204                         if (!tree->buffer)
 205                                 tree->object.parsed = 0;
 206                         if (!tree->object.parsed) {
 207                                 if (parse_tree_buffer(tree, buffer, size))
 208                                         return NULL;
 209                                 *eaten_p = 1;
 210                         }
 211                 }
 212         } else if (type == OBJ_COMMIT) {
 213                 struct commit *commit = lookup_commit(oid);
 214                 if (commit) {
 215                         if (parse_commit_buffer(commit, buffer, size))
 216                                 return NULL;
 217                         if (!get_cached_commit_buffer(commit, NULL)) {
 218                                 set_commit_buffer(commit, buffer, size);
 219                                 *eaten_p = 1;
 220                         }
 221                         obj = &commit->object;
 222                 }
 223         } else if (type == OBJ_TAG) {
 224                 struct tag *tag = lookup_tag(oid);
 225                 if (tag) {
 226                         if (parse_tag_buffer(tag, buffer, size))
 227                                return NULL;
 228                         obj = &tag->object;
 229                 }
 230         } else {
 231                 warning("object %s has unknown type id %d", oid_to_hex(oid), type);
 232                 obj = NULL;
 233         }
 234         return obj;
 235 }
 236
 237 struct object *parse_object_or_die(const struct object_id *oid,
 238                                    const char *name)
 239 {
 240         struct object *o = parse_object(oid);
 241         if (o)
 242                 return o;
 243
 244         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
 245 }
 246
 247 struct object *parse_object(const struct object_id *oid)
 248 {
 249         unsigned long size;
 250         enum object_type type;
 251         int eaten;
 252         const struct object_id *repl = lookup_replace_object(the_repository, oid);
 253         void *buffer;
 254         struct object *obj;
 255
 256         obj = lookup_object(oid->hash);
 257         if (obj && obj->parsed)
 258                 return obj;
 259
 260         if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
 261             (!obj && has_object_file(oid) &&
 262              oid_object_info(the_repository, oid, NULL) == OBJ_BLOB)) {
 263                 if (check_object_signature(repl, NULL, 0, NULL) < 0) {
 264                         error("sha1 mismatch %s", oid_to_hex(oid));
 265                         return NULL;
 266                 }
 267                 parse_blob_buffer(lookup_blob(oid), NULL, 0);
 268                 return lookup_object(oid->hash);
 269         }
 270
 271         buffer = read_object_file(oid, &type, &size);
 272         if (buffer) {
 273                 if (check_object_signature(repl, buffer, size, type_name(type)) < 0) {
 274                         free(buffer);
 275                         error("sha1 mismatch %s", oid_to_hex(repl));
 276                         return NULL;
 277                 }
 278
 279                 obj = parse_object_buffer(oid, type, size, buffer, &eaten);
 280                 if (!eaten)
 281                         free(buffer);
 282                 return obj;
 283         }
 284         return NULL;
 285 }
 286
 287 struct object_list *object_list_insert(struct object *item,
 288                                        struct object_list **list_p)
 289 {
 290         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 291         new_list->item = item;
 292         new_list->next = *list_p;
 293         *list_p = new_list;
 294         return new_list;
 295 }
 296
 297 int object_list_contains(struct object_list *list, struct object *obj)
 298 {
 299         while (list) {
 300                 if (list->item == obj)
 301                         return 1;
 302                 list = list->next;
 303         }
 304         return 0;
 305 }
 306
 307 /*
 308  * A zero-length string to which object_array_entry::name can be
 309  * initialized without requiring a malloc/free.
 310  */
 311 static char object_array_slopbuf[1];
 312
 313 void add_object_array_with_path(struct object *obj, const char *name,
 314                                 struct object_array *array,
 315                                 unsigned mode, const char *path)
 316 {
 317         unsigned nr = array->nr;
 318         unsigned alloc = array->alloc;
 319         struct object_array_entry *objects = array->objects;
 320         struct object_array_entry *entry;
 321
 322         if (nr >= alloc) {
 323                 alloc = (alloc + 32) * 2;
 324                 REALLOC_ARRAY(objects, alloc);
 325                 array->alloc = alloc;
 326                 array->objects = objects;
 327         }
 328         entry = &objects[nr];
 329         entry->item = obj;
 330         if (!name)
 331                 entry->name = NULL;
 332         else if (!*name)
 333                 /* Use our own empty string instead of allocating one: */
 334                 entry->name = object_array_slopbuf;
 335         else
 336                 entry->name = xstrdup(name);
 337         entry->mode = mode;
 338         if (path)
 339                 entry->path = xstrdup(path);
 340         else
 341                 entry->path = NULL;
 342         array->nr = ++nr;
 343 }
 344
 345 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 346 {
 347         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 348 }
 349
 350 /*
 351  * Free all memory associated with an entry; the result is
 352  * in an unspecified state and should not be examined.
 353  */
 354 static void object_array_release_entry(struct object_array_entry *ent)
 355 {
 356         if (ent->name != object_array_slopbuf)
 357                 free(ent->name);
 358         free(ent->path);
 359 }
 360
 361 struct object *object_array_pop(struct object_array *array)
 362 {
 363         struct object *ret;
 364
 365         if (!array->nr)
 366                 return NULL;
 367
 368         ret = array->objects[array->nr - 1].item;
 369         object_array_release_entry(&array->objects[array->nr - 1]);
 370         array->nr--;
 371         return ret;
 372 }
 373
 374 void object_array_filter(struct object_array *array,
 375                          object_array_each_func_t want, void *cb_data)
 376 {
 377         unsigned nr = array->nr, src, dst;
 378         struct object_array_entry *objects = array->objects;
 379
 380         for (src = dst = 0; src < nr; src++) {
 381                 if (want(&objects[src], cb_data)) {
 382                         if (src != dst)
 383                                 objects[dst] = objects[src];
 384                         dst++;
 385                 } else {
 386                         object_array_release_entry(&objects[src]);
 387                 }
 388         }
 389         array->nr = dst;
 390 }
 391
 392 void object_array_clear(struct object_array *array)
 393 {
 394         int i;
 395         for (i = 0; i < array->nr; i++)
 396                 object_array_release_entry(&array->objects[i]);
 397         FREE_AND_NULL(array->objects);
 398         array->nr = array->alloc = 0;
 399 }
 400
 401 /*
 402  * Return true iff array already contains an entry with name.
 403  */
 404 static int contains_name(struct object_array *array, const char *name)
 405 {
 406         unsigned nr = array->nr, i;
 407         struct object_array_entry *object = array->objects;
 408
 409         for (i = 0; i < nr; i++, object++)
 410                 if (!strcmp(object->name, name))
 411                         return 1;
 412         return 0;
 413 }
 414
 415 void object_array_remove_duplicates(struct object_array *array)
 416 {
 417         unsigned nr = array->nr, src;
 418         struct object_array_entry *objects = array->objects;
 419
 420         array->nr = 0;
 421         for (src = 0; src < nr; src++) {
 422                 if (!contains_name(array, objects[src].name)) {
 423                         if (src != array->nr)
 424                                 objects[array->nr] = objects[src];
 425                         array->nr++;
 426                 } else {
 427                         object_array_release_entry(&objects[src]);
 428                 }
 429         }
 430 }
 431
 432 void clear_object_flags(unsigned flags)
 433 {
 434         int i;
 435
 436         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 437                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 438                 if (obj)
 439                         obj->flags &= ~flags;
 440         }
 441 }
 442
 443 void clear_commit_marks_all(unsigned int flags)
 444 {
 445         int i;
 446
 447         for (i = 0; i < the_repository->parsed_objects->obj_hash_size; i++) {
 448                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
 449                 if (obj && obj->type == OBJ_COMMIT)
 450                         obj->flags &= ~flags;
 451         }
 452 }
 453
 454 struct parsed_object_pool *parsed_object_pool_new(void)
 455 {
 456         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 457         memset(o, 0, sizeof(*o));
 458         return o;
 459 }
 460
 461 struct raw_object_store *raw_object_store_new(void)
 462 {
 463         struct raw_object_store *o = xmalloc(sizeof(*o));
 464
 465         memset(o, 0, sizeof(*o));
 466         INIT_LIST_HEAD(&o->packed_git_mru);
 467         return o;
 468 }
 469
 470 static void free_alt_odb(struct alternate_object_database *alt)
 471 {
 472         strbuf_release(&alt->scratch);
 473         oid_array_clear(&alt->loose_objects_cache);
 474         free(alt);
 475 }
 476
 477 static void free_alt_odbs(struct raw_object_store *o)
 478 {
 479         while (o->alt_odb_list) {
 480                 struct alternate_object_database *next;
 481
 482                 next = o->alt_odb_list->next;
 483                 free_alt_odb(o->alt_odb_list);
 484                 o->alt_odb_list = next;
 485         }
 486 }
 487
 488 void raw_object_store_clear(struct raw_object_store *o)
 489 {
 490         FREE_AND_NULL(o->objectdir);
 491         FREE_AND_NULL(o->alternate_db);
 492
 493         free_alt_odbs(o);
 494         o->alt_odb_tail = NULL;
 495
 496         INIT_LIST_HEAD(&o->packed_git_mru);
 497         close_all_packs(o);
 498         o->packed_git = NULL;
 499 }
 500
 501 void parsed_object_pool_clear(struct parsed_object_pool *o)
 502 {
 503         /*
 504          * TOOD free objects in o->obj_hash.
 505          *
 506          * As objects are allocated in slabs (see alloc.c), we do
 507          * not need to free each object, but each slab instead.
 508          */
 509 }