alloc: allow arbitrary repositories for alloc functions
[git/git.git] / 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))
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 free_alt_odbs(o);
502 o->alt_odb_tail = NULL;
503
504 INIT_LIST_HEAD(&o->packed_git_mru);
505 close_all_packs(o);
506 o->packed_git = NULL;
507 }
508
509 void parsed_object_pool_clear(struct parsed_object_pool *o)
510 {
511 /*
512 * As objects are allocated in slabs (see alloc.c), we do
513 * not need to free each object, but each slab instead.
514 *
515 * Before doing so, we need to free any additional memory
516 * the objects may hold.
517 */
518 unsigned i;
519
520 for (i = 0; i < o->obj_hash_size; i++) {
521 struct object *obj = o->obj_hash[i];
522
523 if (!obj)
524 continue;
525
526 if (obj->type == OBJ_TREE)
527 free_tree_buffer((struct tree*)obj);
528 else if (obj->type == OBJ_COMMIT)
529 release_commit_memory((struct commit*)obj);
530 else if (obj->type == OBJ_TAG)
531 release_tag_memory((struct tag*)obj);
532 }
533
534 FREE_AND_NULL(o->obj_hash);
535 o->obj_hash_size = 0;
536
537 clear_alloc_state(o->blob_state);
538 clear_alloc_state(o->tree_state);
539 clear_alloc_state(o->commit_state);
540 clear_alloc_state(o->tag_state);
541 clear_alloc_state(o->object_state);
542 FREE_AND_NULL(o->blob_state);
543 FREE_AND_NULL(o->tree_state);
544 FREE_AND_NULL(o->commit_state);
545 FREE_AND_NULL(o->tag_state);
546 FREE_AND_NULL(o->object_state);
547 }