object.c

   1 #define DISABLE_SIGN_COMPARE_WARNINGS
   2
   3 #include "git-compat-util.h"
   4 #include "gettext.h"
   5 #include "hex.h"
   6 #include "object.h"
   7 #include "replace-object.h"
   8 #include "object-file.h"
   9 #include "blob.h"
  10 #include "statinfo.h"
  11 #include "tree.h"
  12 #include "commit.h"
  13 #include "tag.h"
  14 #include "alloc.h"
  15 #include "commit-graph.h"
  16
  17 unsigned int get_max_object_index(const struct repository *repo)
  18 {
  19         return repo->parsed_objects->obj_hash_size;
  20 }
  21
  22 struct object *get_indexed_object(const struct repository *repo,
  23                                        unsigned int idx)
  24 {
  25         return repo->parsed_objects->obj_hash[idx];
  26 }
  27
  28 static const char *object_type_strings[] = {
  29         NULL,           /* OBJ_NONE = 0 */
  30         "commit",       /* OBJ_COMMIT = 1 */
  31         "tree",         /* OBJ_TREE = 2 */
  32         "blob",         /* OBJ_BLOB = 3 */
  33         "tag",          /* OBJ_TAG = 4 */
  34 };
  35
  36 const char *type_name(unsigned int type)
  37 {
  38         if (type >= ARRAY_SIZE(object_type_strings))
  39                 return NULL;
  40         return object_type_strings[type];
  41 }
  42
  43 int type_from_string_gently(const char *str, ssize_t len, int gentle)
  44 {
  45         int i;
  46
  47         if (len < 0)
  48                 len = strlen(str);
  49
  50         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  51                 if (!xstrncmpz(object_type_strings[i], str, len))
  52                         return i;
  53
  54         if (gentle)
  55                 return -1;
  56
  57         die(_("invalid object type \"%s\""), str);
  58 }
  59
  60 /*
  61  * Return a numerical hash value between 0 and n-1 for the object with
  62  * the specified sha1.  n must be a power of 2.  Please note that the
  63  * return value is *not* consistent across computer architectures.
  64  */
  65 static unsigned int hash_obj(const struct object_id *oid, unsigned int n)
  66 {
  67         return oidhash(oid) & (n - 1);
  68 }
  69
  70 /*
  71  * Insert obj into the hash table hash, which has length size (which
  72  * must be a power of 2).  On collisions, simply overflow to the next
  73  * empty bucket.
  74  */
  75 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  76 {
  77         unsigned int j = hash_obj(&obj->oid, size);
  78
  79         while (hash[j]) {
  80                 j++;
  81                 if (j >= size)
  82                         j = 0;
  83         }
  84         hash[j] = obj;
  85 }
  86
  87 /*
  88  * Look up the record for the given sha1 in the hash map stored in
  89  * obj_hash.  Return NULL if it was not found.
  90  */
  91 struct object *lookup_object(struct repository *r, const struct object_id *oid)
  92 {
  93         unsigned int i, first;
  94         struct object *obj;
  95
  96         if (!r->parsed_objects->obj_hash)
  97                 return NULL;
  98
  99         first = i = hash_obj(oid, r->parsed_objects->obj_hash_size);
 100         while ((obj = r->parsed_objects->obj_hash[i]) != NULL) {
 101                 if (oideq(oid, &obj->oid))
 102                         break;
 103                 i++;
 104                 if (i == r->parsed_objects->obj_hash_size)
 105                         i = 0;
 106         }
 107         if (obj && i != first) {
 108                 /*
 109                  * Move object to where we started to look for it so
 110                  * that we do not need to walk the hash table the next
 111                  * time we look for it.
 112                  */
 113                 SWAP(r->parsed_objects->obj_hash[i],
 114                      r->parsed_objects->obj_hash[first]);
 115         }
 116         return obj;
 117 }
 118
 119 /*
 120  * Increase the size of the hash map stored in obj_hash to the next
 121  * power of 2 (but at least 32).  Copy the existing values to the new
 122  * hash map.
 123  */
 124 static void grow_object_hash(struct repository *r)
 125 {
 126         int i;
 127         /*
 128          * Note that this size must always be power-of-2 to match hash_obj
 129          * above.
 130          */
 131         int new_hash_size = r->parsed_objects->obj_hash_size < 32 ? 32 : 2 * r->parsed_objects->obj_hash_size;
 132         struct object **new_hash;
 133
 134         CALLOC_ARRAY(new_hash, new_hash_size);
 135         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 136                 struct object *obj = r->parsed_objects->obj_hash[i];
 137
 138                 if (!obj)
 139                         continue;
 140                 insert_obj_hash(obj, new_hash, new_hash_size);
 141         }
 142         free(r->parsed_objects->obj_hash);
 143         r->parsed_objects->obj_hash = new_hash;
 144         r->parsed_objects->obj_hash_size = new_hash_size;
 145 }
 146
 147 void *create_object(struct repository *r, const struct object_id *oid, void *o)
 148 {
 149         struct object *obj = o;
 150
 151         obj->parsed = 0;
 152         obj->flags = 0;
 153         oidcpy(&obj->oid, oid);
 154
 155         if (r->parsed_objects->obj_hash_size - 1 <= r->parsed_objects->nr_objs * 2)
 156                 grow_object_hash(r);
 157
 158         insert_obj_hash(obj, r->parsed_objects->obj_hash,
 159                         r->parsed_objects->obj_hash_size);
 160         r->parsed_objects->nr_objs++;
 161         return obj;
 162 }
 163
 164 void *object_as_type(struct object *obj, enum object_type type, int quiet)
 165 {
 166         if (obj->type == type)
 167                 return obj;
 168         else if (obj->type == OBJ_NONE) {
 169                 if (type == OBJ_COMMIT)
 170                         init_commit_node((struct commit *) obj);
 171                 else
 172                         obj->type = type;
 173                 return obj;
 174         }
 175         else {
 176                 if (!quiet)
 177                         error(_("object %s is a %s, not a %s"),
 178                               oid_to_hex(&obj->oid),
 179                               type_name(obj->type), type_name(type));
 180                 return NULL;
 181         }
 182 }
 183
 184 struct object *lookup_unknown_object(struct repository *r, const struct object_id *oid)
 185 {
 186         struct object *obj = lookup_object(r, oid);
 187         if (!obj)
 188                 obj = create_object(r, oid, alloc_object_node(r));
 189         return obj;
 190 }
 191
 192 struct object *lookup_object_by_type(struct repository *r,
 193                             const struct object_id *oid,
 194                             enum object_type type)
 195 {
 196         switch (type) {
 197         case OBJ_COMMIT:
 198                 return (struct object *)lookup_commit(r, oid);
 199         case OBJ_TREE:
 200                 return (struct object *)lookup_tree(r, oid);
 201         case OBJ_TAG:
 202                 return (struct object *)lookup_tag(r, oid);
 203         case OBJ_BLOB:
 204                 return (struct object *)lookup_blob(r, oid);
 205         default:
 206                 BUG("unknown object type %d", type);
 207         }
 208 }
 209
 210 enum peel_status peel_object(struct repository *r,
 211                              const struct object_id *name,
 212                              struct object_id *oid)
 213 {
 214         struct object *o = lookup_unknown_object(r, name);
 215
 216         if (o->type == OBJ_NONE) {
 217                 int type = odb_read_object_info(r->objects, name, NULL);
 218                 if (type < 0 || !object_as_type(o, type, 0))
 219                         return PEEL_INVALID;
 220         }
 221
 222         if (o->type != OBJ_TAG)
 223                 return PEEL_NON_TAG;
 224
 225         o = deref_tag_noverify(r, o);
 226         if (!o)
 227                 return PEEL_INVALID;
 228
 229         oidcpy(oid, &o->oid);
 230         return PEEL_PEELED;
 231 }
 232
 233 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)
 234 {
 235         struct object *obj;
 236         *eaten_p = 0;
 237
 238         obj = NULL;
 239         if (type == OBJ_BLOB) {
 240                 struct blob *blob = lookup_blob(r, oid);
 241                 if (blob) {
 242                         parse_blob_buffer(blob);
 243                         obj = &blob->object;
 244                 }
 245         } else if (type == OBJ_TREE) {
 246                 struct tree *tree = lookup_tree(r, oid);
 247                 if (tree) {
 248                         obj = &tree->object;
 249                         if (!tree->buffer)
 250                                 tree->object.parsed = 0;
 251                         if (!tree->object.parsed) {
 252                                 if (parse_tree_buffer(tree, buffer, size))
 253                                         return NULL;
 254                                 *eaten_p = 1;
 255                         }
 256                 }
 257         } else if (type == OBJ_COMMIT) {
 258                 struct commit *commit = lookup_commit(r, oid);
 259                 if (commit) {
 260                         if (parse_commit_buffer(r, commit, buffer, size, 1))
 261                                 return NULL;
 262                         if (save_commit_buffer &&
 263                             !get_cached_commit_buffer(r, commit, NULL)) {
 264                                 set_commit_buffer(r, commit, buffer, size);
 265                                 *eaten_p = 1;
 266                         }
 267                         obj = &commit->object;
 268                 }
 269         } else if (type == OBJ_TAG) {
 270                 struct tag *tag = lookup_tag(r, oid);
 271                 if (tag) {
 272                         if (parse_tag_buffer(r, tag, buffer, size))
 273                                return NULL;
 274                         obj = &tag->object;
 275                 }
 276         } else {
 277                 warning(_("object %s has unknown type id %d"), oid_to_hex(oid), type);
 278                 obj = NULL;
 279         }
 280         return obj;
 281 }
 282
 283 struct object *parse_object_or_die(struct repository *repo,
 284                                    const struct object_id *oid,
 285                                    const char *name)
 286 {
 287         struct object *o = parse_object(repo, oid);
 288         if (o)
 289                 return o;
 290
 291         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
 292 }
 293
 294 struct object *parse_object_with_flags(struct repository *r,
 295                                        const struct object_id *oid,
 296                                        enum parse_object_flags flags)
 297 {
 298         int skip_hash = !!(flags & PARSE_OBJECT_SKIP_HASH_CHECK);
 299         int discard_tree = !!(flags & PARSE_OBJECT_DISCARD_TREE);
 300         unsigned long size;
 301         enum object_type type;
 302         int eaten;
 303         const struct object_id *repl = lookup_replace_object(r, oid);
 304         void *buffer;
 305         struct object *obj;
 306
 307         obj = lookup_object(r, oid);
 308         if (obj && obj->parsed)
 309                 return obj;
 310
 311         if (skip_hash) {
 312                 struct commit *commit = lookup_commit_in_graph(r, repl);
 313                 if (commit)
 314                         return &commit->object;
 315         }
 316
 317         if ((!obj || obj->type == OBJ_BLOB) &&
 318             odb_read_object_info(r->objects, oid, NULL) == OBJ_BLOB) {
 319                 if (!skip_hash && stream_object_signature(r, repl) < 0) {
 320                         error(_("hash mismatch %s"), oid_to_hex(oid));
 321                         return NULL;
 322                 }
 323                 parse_blob_buffer(lookup_blob(r, oid));
 324                 return lookup_object(r, oid);
 325         }
 326
 327         /*
 328          * If the caller does not care about the tree buffer and does not
 329          * care about checking the hash, we can simply verify that we
 330          * have the on-disk object with the correct type.
 331          */
 332         if (skip_hash && discard_tree &&
 333             (!obj || obj->type == OBJ_TREE) &&
 334             odb_read_object_info(r->objects, oid, NULL) == OBJ_TREE) {
 335                 return &lookup_tree(r, oid)->object;
 336         }
 337
 338         buffer = odb_read_object(r->objects, oid, &type, &size);
 339         if (buffer) {
 340                 if (!skip_hash &&
 341                     check_object_signature(r, repl, buffer, size, type) < 0) {
 342                         free(buffer);
 343                         error(_("hash mismatch %s"), oid_to_hex(repl));
 344                         return NULL;
 345                 }
 346
 347                 obj = parse_object_buffer(r, oid, type, size,
 348                                           buffer, &eaten);
 349                 if (!eaten)
 350                         free(buffer);
 351                 if (discard_tree && type == OBJ_TREE)
 352                         free_tree_buffer((struct tree *)obj);
 353                 return obj;
 354         }
 355         return NULL;
 356 }
 357
 358 struct object *parse_object(struct repository *r, const struct object_id *oid)
 359 {
 360         return parse_object_with_flags(r, oid, 0);
 361 }
 362
 363 struct object_list *object_list_insert(struct object *item,
 364                                        struct object_list **list_p)
 365 {
 366         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 367         new_list->item = item;
 368         new_list->next = *list_p;
 369         *list_p = new_list;
 370         return new_list;
 371 }
 372
 373 int object_list_contains(struct object_list *list, struct object *obj)
 374 {
 375         while (list) {
 376                 if (list->item == obj)
 377                         return 1;
 378                 list = list->next;
 379         }
 380         return 0;
 381 }
 382
 383 void object_list_free(struct object_list **list)
 384 {
 385         while (*list) {
 386                 struct object_list *p = *list;
 387                 *list = p->next;
 388                 free(p);
 389         }
 390 }
 391
 392 /*
 393  * A zero-length string to which object_array_entry::name can be
 394  * initialized without requiring a malloc/free.
 395  */
 396 static char object_array_slopbuf[1];
 397
 398 void object_array_init(struct object_array *array)
 399 {
 400         struct object_array blank = OBJECT_ARRAY_INIT;
 401         memcpy(array, &blank, sizeof(*array));
 402 }
 403
 404 void add_object_array_with_path(struct object *obj, const char *name,
 405                                 struct object_array *array,
 406                                 unsigned mode, const char *path)
 407 {
 408         unsigned nr = array->nr;
 409         unsigned alloc = array->alloc;
 410         struct object_array_entry *objects = array->objects;
 411         struct object_array_entry *entry;
 412
 413         if (nr >= alloc) {
 414                 alloc = (alloc + 32) * 2;
 415                 REALLOC_ARRAY(objects, alloc);
 416                 array->alloc = alloc;
 417                 array->objects = objects;
 418         }
 419         entry = &objects[nr];
 420         entry->item = obj;
 421         if (!name)
 422                 entry->name = NULL;
 423         else if (!*name)
 424                 /* Use our own empty string instead of allocating one: */
 425                 entry->name = object_array_slopbuf;
 426         else
 427                 entry->name = xstrdup(name);
 428         entry->mode = mode;
 429         if (path)
 430                 entry->path = xstrdup(path);
 431         else
 432                 entry->path = NULL;
 433         array->nr = ++nr;
 434 }
 435
 436 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 437 {
 438         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 439 }
 440
 441 /*
 442  * Free all memory associated with an entry; the result is
 443  * in an unspecified state and should not be examined.
 444  */
 445 static void object_array_release_entry(struct object_array_entry *ent)
 446 {
 447         if (ent->name != object_array_slopbuf)
 448                 free(ent->name);
 449         free(ent->path);
 450 }
 451
 452 struct object *object_array_pop(struct object_array *array)
 453 {
 454         struct object *ret;
 455
 456         if (!array->nr)
 457                 return NULL;
 458
 459         ret = array->objects[array->nr - 1].item;
 460         object_array_release_entry(&array->objects[array->nr - 1]);
 461         array->nr--;
 462         return ret;
 463 }
 464
 465 void object_array_filter(struct object_array *array,
 466                          object_array_each_func_t want, void *cb_data)
 467 {
 468         unsigned nr = array->nr, src, dst;
 469         struct object_array_entry *objects = array->objects;
 470
 471         for (src = dst = 0; src < nr; src++) {
 472                 if (want(&objects[src], cb_data)) {
 473                         if (src != dst)
 474                                 objects[dst] = objects[src];
 475                         dst++;
 476                 } else {
 477                         object_array_release_entry(&objects[src]);
 478                 }
 479         }
 480         array->nr = dst;
 481 }
 482
 483 void object_array_clear(struct object_array *array)
 484 {
 485         int i;
 486         for (i = 0; i < array->nr; i++)
 487                 object_array_release_entry(&array->objects[i]);
 488         FREE_AND_NULL(array->objects);
 489         array->nr = array->alloc = 0;
 490 }
 491
 492 void clear_object_flags(struct repository *repo, unsigned flags)
 493 {
 494         int i;
 495
 496         for (i = 0; i < repo->parsed_objects->obj_hash_size; i++) {
 497                 struct object *obj = repo->parsed_objects->obj_hash[i];
 498                 if (obj)
 499                         obj->flags &= ~flags;
 500         }
 501 }
 502
 503 void repo_clear_commit_marks(struct repository *r, unsigned int flags)
 504 {
 505         int i;
 506
 507         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
 508                 struct object *obj = r->parsed_objects->obj_hash[i];
 509                 if (obj && obj->type == OBJ_COMMIT)
 510                         obj->flags &= ~flags;
 511         }
 512 }
 513
 514 struct parsed_object_pool *parsed_object_pool_new(struct repository *repo)
 515 {
 516         struct parsed_object_pool *o = xmalloc(sizeof(*o));
 517         memset(o, 0, sizeof(*o));
 518
 519         o->repo = repo;
 520         o->blob_state = allocate_alloc_state();
 521         o->tree_state = allocate_alloc_state();
 522         o->commit_state = allocate_alloc_state();
 523         o->tag_state = allocate_alloc_state();
 524         o->object_state = allocate_alloc_state();
 525
 526         o->is_shallow = -1;
 527         CALLOC_ARRAY(o->shallow_stat, 1);
 528
 529         o->buffer_slab = allocate_commit_buffer_slab();
 530
 531         return o;
 532 }
 533
 534 void parsed_object_pool_reset_commit_grafts(struct parsed_object_pool *o)
 535 {
 536         for (int i = 0; i < o->grafts_nr; i++) {
 537                 unparse_commit(o->repo, &o->grafts[i]->oid);
 538                 free(o->grafts[i]);
 539         }
 540         o->grafts_nr = 0;
 541         o->commit_graft_prepared = 0;
 542 }
 543
 544 void parsed_object_pool_clear(struct parsed_object_pool *o)
 545 {
 546         /*
 547          * As objects are allocated in slabs (see alloc.c), we do
 548          * not need to free each object, but each slab instead.
 549          *
 550          * Before doing so, we need to free any additional memory
 551          * the objects may hold.
 552          */
 553         unsigned i;
 554
 555         for (i = 0; i < o->obj_hash_size; i++) {
 556                 struct object *obj = o->obj_hash[i];
 557
 558                 if (!obj)
 559                         continue;
 560
 561                 if (obj->type == OBJ_TREE)
 562                         free_tree_buffer((struct tree*)obj);
 563                 else if (obj->type == OBJ_COMMIT)
 564                         release_commit_memory(o, (struct commit*)obj);
 565                 else if (obj->type == OBJ_TAG)
 566                         release_tag_memory((struct tag*)obj);
 567         }
 568
 569         FREE_AND_NULL(o->obj_hash);
 570         o->obj_hash_size = 0;
 571
 572         free_commit_buffer_slab(o->buffer_slab);
 573         o->buffer_slab = NULL;
 574
 575         parsed_object_pool_reset_commit_grafts(o);
 576         clear_alloc_state(o->blob_state);
 577         clear_alloc_state(o->tree_state);
 578         clear_alloc_state(o->commit_state);
 579         clear_alloc_state(o->tag_state);
 580         clear_alloc_state(o->object_state);
 581         stat_validity_clear(o->shallow_stat);
 582         FREE_AND_NULL(o->blob_state);
 583         FREE_AND_NULL(o->tree_state);
 584         FREE_AND_NULL(o->commit_state);
 585         FREE_AND_NULL(o->tag_state);
 586         FREE_AND_NULL(o->object_state);
 587         FREE_AND_NULL(o->shallow_stat);
 588 }