object-store: move packed_git and packed_git_mru to object store
[git/git.git] / object.c
1 #include "cache.h"
2 #include "object.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "commit.h"
6 #include "tag.h"
7 #include "object-store.h"
8
9 static struct object **obj_hash;
10 static int nr_objs, obj_hash_size;
11
12 unsigned int get_max_object_index(void)
13 {
14 return obj_hash_size;
15 }
16
17 struct object *get_indexed_object(unsigned int idx)
18 {
19 return 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 *typename(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 (!obj_hash)
92 return NULL;
93
94 first = i = hash_obj(sha1, obj_hash_size);
95 while ((obj = obj_hash[i]) != NULL) {
96 if (!hashcmp(sha1, obj->oid.hash))
97 break;
98 i++;
99 if (i == 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(obj_hash[i], obj_hash[first]);
109 }
110 return obj;
111 }
112
113 /*
114 * Increase the size of the hash map stored in obj_hash to the next
115 * power of 2 (but at least 32). Copy the existing values to the new
116 * hash map.
117 */
118 static void grow_object_hash(void)
119 {
120 int i;
121 /*
122 * Note that this size must always be power-of-2 to match hash_obj
123 * above.
124 */
125 int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
126 struct object **new_hash;
127
128 new_hash = xcalloc(new_hash_size, sizeof(struct object *));
129 for (i = 0; i < obj_hash_size; i++) {
130 struct object *obj = obj_hash[i];
131 if (!obj)
132 continue;
133 insert_obj_hash(obj, new_hash, new_hash_size);
134 }
135 free(obj_hash);
136 obj_hash = new_hash;
137 obj_hash_size = new_hash_size;
138 }
139
140 void *create_object(const unsigned char *sha1, void *o)
141 {
142 struct object *obj = o;
143
144 obj->parsed = 0;
145 obj->flags = 0;
146 hashcpy(obj->oid.hash, sha1);
147
148 if (obj_hash_size - 1 <= nr_objs * 2)
149 grow_object_hash();
150
151 insert_obj_hash(obj, obj_hash, obj_hash_size);
152 nr_objs++;
153 return obj;
154 }
155
156 void *object_as_type(struct object *obj, enum object_type type, int quiet)
157 {
158 if (obj->type == type)
159 return obj;
160 else if (obj->type == OBJ_NONE) {
161 if (type == OBJ_COMMIT)
162 ((struct commit *)obj)->index = alloc_commit_index();
163 obj->type = type;
164 return obj;
165 }
166 else {
167 if (!quiet)
168 error("object %s is a %s, not a %s",
169 oid_to_hex(&obj->oid),
170 typename(obj->type), typename(type));
171 return NULL;
172 }
173 }
174
175 struct object *lookup_unknown_object(const unsigned char *sha1)
176 {
177 struct object *obj = lookup_object(sha1);
178 if (!obj)
179 obj = create_object(sha1, alloc_object_node());
180 return obj;
181 }
182
183 struct object *parse_object_buffer(const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
184 {
185 struct object *obj;
186 *eaten_p = 0;
187
188 obj = NULL;
189 if (type == OBJ_BLOB) {
190 struct blob *blob = lookup_blob(oid);
191 if (blob) {
192 if (parse_blob_buffer(blob, buffer, size))
193 return NULL;
194 obj = &blob->object;
195 }
196 } else if (type == OBJ_TREE) {
197 struct tree *tree = lookup_tree(oid);
198 if (tree) {
199 obj = &tree->object;
200 if (!tree->buffer)
201 tree->object.parsed = 0;
202 if (!tree->object.parsed) {
203 if (parse_tree_buffer(tree, buffer, size))
204 return NULL;
205 *eaten_p = 1;
206 }
207 }
208 } else if (type == OBJ_COMMIT) {
209 struct commit *commit = lookup_commit(oid);
210 if (commit) {
211 if (parse_commit_buffer(commit, buffer, size))
212 return NULL;
213 if (!get_cached_commit_buffer(commit, NULL)) {
214 set_commit_buffer(commit, buffer, size);
215 *eaten_p = 1;
216 }
217 obj = &commit->object;
218 }
219 } else if (type == OBJ_TAG) {
220 struct tag *tag = lookup_tag(oid);
221 if (tag) {
222 if (parse_tag_buffer(tag, buffer, size))
223 return NULL;
224 obj = &tag->object;
225 }
226 } else {
227 warning("object %s has unknown type id %d", oid_to_hex(oid), type);
228 obj = NULL;
229 }
230 return obj;
231 }
232
233 struct object *parse_object_or_die(const struct object_id *oid,
234 const char *name)
235 {
236 struct object *o = parse_object(oid);
237 if (o)
238 return o;
239
240 die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
241 }
242
243 struct object *parse_object(const struct object_id *oid)
244 {
245 unsigned long size;
246 enum object_type type;
247 int eaten;
248 const unsigned char *repl = lookup_replace_object(oid->hash);
249 void *buffer;
250 struct object *obj;
251
252 obj = lookup_object(oid->hash);
253 if (obj && obj->parsed)
254 return obj;
255
256 if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
257 (!obj && has_object_file(oid) &&
258 sha1_object_info(oid->hash, NULL) == OBJ_BLOB)) {
259 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
260 error("sha1 mismatch %s", oid_to_hex(oid));
261 return NULL;
262 }
263 parse_blob_buffer(lookup_blob(oid), NULL, 0);
264 return lookup_object(oid->hash);
265 }
266
267 buffer = read_sha1_file(oid->hash, &type, &size);
268 if (buffer) {
269 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
270 free(buffer);
271 error("sha1 mismatch %s", sha1_to_hex(repl));
272 return NULL;
273 }
274
275 obj = parse_object_buffer(oid, type, size, buffer, &eaten);
276 if (!eaten)
277 free(buffer);
278 return obj;
279 }
280 return NULL;
281 }
282
283 struct object_list *object_list_insert(struct object *item,
284 struct object_list **list_p)
285 {
286 struct object_list *new_list = xmalloc(sizeof(struct object_list));
287 new_list->item = item;
288 new_list->next = *list_p;
289 *list_p = new_list;
290 return new_list;
291 }
292
293 int object_list_contains(struct object_list *list, struct object *obj)
294 {
295 while (list) {
296 if (list->item == obj)
297 return 1;
298 list = list->next;
299 }
300 return 0;
301 }
302
303 /*
304 * A zero-length string to which object_array_entry::name can be
305 * initialized without requiring a malloc/free.
306 */
307 static char object_array_slopbuf[1];
308
309 void add_object_array_with_path(struct object *obj, const char *name,
310 struct object_array *array,
311 unsigned mode, const char *path)
312 {
313 unsigned nr = array->nr;
314 unsigned alloc = array->alloc;
315 struct object_array_entry *objects = array->objects;
316 struct object_array_entry *entry;
317
318 if (nr >= alloc) {
319 alloc = (alloc + 32) * 2;
320 REALLOC_ARRAY(objects, alloc);
321 array->alloc = alloc;
322 array->objects = objects;
323 }
324 entry = &objects[nr];
325 entry->item = obj;
326 if (!name)
327 entry->name = NULL;
328 else if (!*name)
329 /* Use our own empty string instead of allocating one: */
330 entry->name = object_array_slopbuf;
331 else
332 entry->name = xstrdup(name);
333 entry->mode = mode;
334 if (path)
335 entry->path = xstrdup(path);
336 else
337 entry->path = NULL;
338 array->nr = ++nr;
339 }
340
341 void add_object_array(struct object *obj, const char *name, struct object_array *array)
342 {
343 add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
344 }
345
346 /*
347 * Free all memory associated with an entry; the result is
348 * in an unspecified state and should not be examined.
349 */
350 static void object_array_release_entry(struct object_array_entry *ent)
351 {
352 if (ent->name != object_array_slopbuf)
353 free(ent->name);
354 free(ent->path);
355 }
356
357 struct object *object_array_pop(struct object_array *array)
358 {
359 struct object *ret;
360
361 if (!array->nr)
362 return NULL;
363
364 ret = array->objects[array->nr - 1].item;
365 object_array_release_entry(&array->objects[array->nr - 1]);
366 array->nr--;
367 return ret;
368 }
369
370 void object_array_filter(struct object_array *array,
371 object_array_each_func_t want, void *cb_data)
372 {
373 unsigned nr = array->nr, src, dst;
374 struct object_array_entry *objects = array->objects;
375
376 for (src = dst = 0; src < nr; src++) {
377 if (want(&objects[src], cb_data)) {
378 if (src != dst)
379 objects[dst] = objects[src];
380 dst++;
381 } else {
382 object_array_release_entry(&objects[src]);
383 }
384 }
385 array->nr = dst;
386 }
387
388 void object_array_clear(struct object_array *array)
389 {
390 int i;
391 for (i = 0; i < array->nr; i++)
392 object_array_release_entry(&array->objects[i]);
393 FREE_AND_NULL(array->objects);
394 array->nr = array->alloc = 0;
395 }
396
397 /*
398 * Return true iff array already contains an entry with name.
399 */
400 static int contains_name(struct object_array *array, const char *name)
401 {
402 unsigned nr = array->nr, i;
403 struct object_array_entry *object = array->objects;
404
405 for (i = 0; i < nr; i++, object++)
406 if (!strcmp(object->name, name))
407 return 1;
408 return 0;
409 }
410
411 void object_array_remove_duplicates(struct object_array *array)
412 {
413 unsigned nr = array->nr, src;
414 struct object_array_entry *objects = array->objects;
415
416 array->nr = 0;
417 for (src = 0; src < nr; src++) {
418 if (!contains_name(array, objects[src].name)) {
419 if (src != array->nr)
420 objects[array->nr] = objects[src];
421 array->nr++;
422 } else {
423 object_array_release_entry(&objects[src]);
424 }
425 }
426 }
427
428 void clear_object_flags(unsigned flags)
429 {
430 int i;
431
432 for (i=0; i < obj_hash_size; i++) {
433 struct object *obj = obj_hash[i];
434 if (obj)
435 obj->flags &= ~flags;
436 }
437 }
438
439 void clear_commit_marks_all(unsigned int flags)
440 {
441 int i;
442
443 for (i = 0; i < obj_hash_size; i++) {
444 struct object *obj = obj_hash[i];
445 if (obj && obj->type == OBJ_COMMIT)
446 obj->flags &= ~flags;
447 }
448 }
449
450 struct raw_object_store *raw_object_store_new(void)
451 {
452 struct raw_object_store *o = xmalloc(sizeof(*o));
453
454 memset(o, 0, sizeof(*o));
455 INIT_LIST_HEAD(&o->packed_git_mru);
456 return o;
457 }
458
459 static void free_alt_odb(struct alternate_object_database *alt)
460 {
461 strbuf_release(&alt->scratch);
462 oid_array_clear(&alt->loose_objects_cache);
463 free(alt);
464 }
465
466 static void free_alt_odbs(struct raw_object_store *o)
467 {
468 while (o->alt_odb_list) {
469 struct alternate_object_database *next;
470
471 next = o->alt_odb_list->next;
472 free_alt_odb(o->alt_odb_list);
473 o->alt_odb_list = next;
474 }
475 }
476
477 void raw_object_store_clear(struct raw_object_store *o)
478 {
479 FREE_AND_NULL(o->objectdir);
480 FREE_AND_NULL(o->alternate_db);
481
482 free_alt_odbs(o);
483 o->alt_odb_tail = NULL;
484
485 INIT_LIST_HEAD(&o->packed_git_mru);
486 /*
487 * TODO: call close_all_packs once migrated to
488 * take an object store argument
489 */
490 }