Merge branch 'dl/complete-stash'
[git] / object.c
1 #include "cache.h"
2 #include "object.h"
3 #include "replace-object.h"
4 #include "object-store.h"
5 #include "blob.h"
6 #include "tree.h"
7 #include "commit.h"
8 #include "tag.h"
9 #include "alloc.h"
10 #include "packfile.h"
11 #include "commit-graph.h"
12
13 unsigned int get_max_object_index(void)
14 {
15         return the_repository->parsed_objects->obj_hash_size;
16 }
17
18 struct object *get_indexed_object(unsigned int idx)
19 {
20         return the_repository->parsed_objects->obj_hash[idx];
21 }
22
23 static const char *object_type_strings[] = {
24         NULL,           /* OBJ_NONE = 0 */
25         "commit",       /* OBJ_COMMIT = 1 */
26         "tree",         /* OBJ_TREE = 2 */
27         "blob",         /* OBJ_BLOB = 3 */
28         "tag",          /* OBJ_TAG = 4 */
29 };
30
31 const char *type_name(unsigned int type)
32 {
33         if (type >= ARRAY_SIZE(object_type_strings))
34                 return NULL;
35         return object_type_strings[type];
36 }
37
38 int type_from_string_gently(const char *str, ssize_t len, int gentle)
39 {
40         int i;
41
42         if (len < 0)
43                 len = strlen(str);
44
45         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
46                 if (!strncmp(str, object_type_strings[i], len) &&
47                     object_type_strings[i][len] == '\0')
48                         return i;
49
50         if (gentle)
51                 return -1;
52
53         die(_("invalid object type \"%s\""), str);
54 }
55
56 /*
57  * Return a numerical hash value between 0 and n-1 for the object with
58  * the specified sha1.  n must be a power of 2.  Please note that the
59  * return value is *not* consistent across computer architectures.
60  */
61 static unsigned int hash_obj(const struct object_id *oid, unsigned int n)
62 {
63         return oidhash(oid) & (n - 1);
64 }
65
66 /*
67  * Insert obj into the hash table hash, which has length size (which
68  * must be a power of 2).  On collisions, simply overflow to the next
69  * empty bucket.
70  */
71 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
72 {
73         unsigned int j = hash_obj(&obj->oid, size);
74
75         while (hash[j]) {
76                 j++;
77                 if (j >= size)
78                         j = 0;
79         }
80         hash[j] = obj;
81 }
82
83 /*
84  * Look up the record for the given sha1 in the hash map stored in
85  * obj_hash.  Return NULL if it was not found.
86  */
87 struct object *lookup_object(struct repository *r, const struct object_id *oid)
88 {
89         unsigned int i, first;
90         struct object *obj;
91
92         if (!r->parsed_objects->obj_hash)
93                 return NULL;
94
95         first = i = hash_obj(oid, r->parsed_objects->obj_hash_size);
96         while ((obj = r->parsed_objects->obj_hash[i]) != NULL) {
97                 if (oideq(oid, &obj->oid))
98                         break;
99                 i++;
100                 if (i == r->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(r->parsed_objects->obj_hash[i],
110                      r->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         CALLOC_ARRAY(new_hash, new_hash_size);
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 struct object_id *oid, void *o)
144 {
145         struct object *obj = o;
146
147         obj->parsed = 0;
148         obj->flags = 0;
149         oidcpy(&obj->oid, oid);
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                         init_commit_node((struct commit *) obj);
167                 else
168                         obj->type = type;
169                 return obj;
170         }
171         else {
172                 if (!quiet)
173                         error(_("object %s is a %s, not a %s"),
174                               oid_to_hex(&obj->oid),
175                               type_name(obj->type), type_name(type));
176                 return NULL;
177         }
178 }
179
180 struct object *lookup_unknown_object(struct repository *r, const struct object_id *oid)
181 {
182         struct object *obj = lookup_object(r, oid);
183         if (!obj)
184                 obj = create_object(r, oid, alloc_object_node(r));
185         return obj;
186 }
187
188 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)
189 {
190         struct object *obj;
191         *eaten_p = 0;
192
193         obj = NULL;
194         if (type == OBJ_BLOB) {
195                 struct blob *blob = lookup_blob(r, 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(r, 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(r, oid);
215                 if (commit) {
216                         if (parse_commit_buffer(r, commit, buffer, size, 1))
217                                 return NULL;
218                         if (!get_cached_commit_buffer(r, commit, NULL)) {
219                                 set_commit_buffer(r, 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(r, oid);
226                 if (tag) {
227                         if (parse_tag_buffer(r, 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(the_repository, 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(struct repository *r, 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(r, oid);
254         void *buffer;
255         struct object *obj;
256
257         obj = lookup_object(r, oid);
258         if (obj && obj->parsed)
259                 return obj;
260
261         if ((obj && obj->type == OBJ_BLOB && repo_has_object_file(r, oid)) ||
262             (!obj && repo_has_object_file(r, oid) &&
263              oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
264                 if (check_object_signature(r, repl, NULL, 0, NULL) < 0) {
265                         error(_("hash mismatch %s"), oid_to_hex(oid));
266                         return NULL;
267                 }
268                 parse_blob_buffer(lookup_blob(r, oid), NULL, 0);
269                 return lookup_object(r, oid);
270         }
271
272         buffer = repo_read_object_file(r, oid, &type, &size);
273         if (buffer) {
274                 if (check_object_signature(r, repl, buffer, size,
275                                            type_name(type)) < 0) {
276                         free(buffer);
277                         error(_("hash mismatch %s"), oid_to_hex(repl));
278                         return NULL;
279                 }
280
281                 obj = parse_object_buffer(r, oid, type, size,
282                                           buffer, &eaten);
283                 if (!eaten)
284                         free(buffer);
285                 return obj;
286         }
287         return NULL;
288 }
289
290 struct object_list *object_list_insert(struct object *item,
291                                        struct object_list **list_p)
292 {
293         struct object_list *new_list = xmalloc(sizeof(struct object_list));
294         new_list->item = item;
295         new_list->next = *list_p;
296         *list_p = new_list;
297         return new_list;
298 }
299
300 int object_list_contains(struct object_list *list, struct object *obj)
301 {
302         while (list) {
303                 if (list->item == obj)
304                         return 1;
305                 list = list->next;
306         }
307         return 0;
308 }
309
310 void object_list_free(struct object_list **list)
311 {
312         while (*list) {
313                 struct object_list *p = *list;
314                 *list = p->next;
315                 free(p);
316         }
317 }
318
319 /*
320  * A zero-length string to which object_array_entry::name can be
321  * initialized without requiring a malloc/free.
322  */
323 static char object_array_slopbuf[1];
324
325 void add_object_array_with_path(struct object *obj, const char *name,
326                                 struct object_array *array,
327                                 unsigned mode, const char *path)
328 {
329         unsigned nr = array->nr;
330         unsigned alloc = array->alloc;
331         struct object_array_entry *objects = array->objects;
332         struct object_array_entry *entry;
333
334         if (nr >= alloc) {
335                 alloc = (alloc + 32) * 2;
336                 REALLOC_ARRAY(objects, alloc);
337                 array->alloc = alloc;
338                 array->objects = objects;
339         }
340         entry = &objects[nr];
341         entry->item = obj;
342         if (!name)
343                 entry->name = NULL;
344         else if (!*name)
345                 /* Use our own empty string instead of allocating one: */
346                 entry->name = object_array_slopbuf;
347         else
348                 entry->name = xstrdup(name);
349         entry->mode = mode;
350         if (path)
351                 entry->path = xstrdup(path);
352         else
353                 entry->path = NULL;
354         array->nr = ++nr;
355 }
356
357 void add_object_array(struct object *obj, const char *name, struct object_array *array)
358 {
359         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
360 }
361
362 /*
363  * Free all memory associated with an entry; the result is
364  * in an unspecified state and should not be examined.
365  */
366 static void object_array_release_entry(struct object_array_entry *ent)
367 {
368         if (ent->name != object_array_slopbuf)
369                 free(ent->name);
370         free(ent->path);
371 }
372
373 struct object *object_array_pop(struct object_array *array)
374 {
375         struct object *ret;
376
377         if (!array->nr)
378                 return NULL;
379
380         ret = array->objects[array->nr - 1].item;
381         object_array_release_entry(&array->objects[array->nr - 1]);
382         array->nr--;
383         return ret;
384 }
385
386 void object_array_filter(struct object_array *array,
387                          object_array_each_func_t want, void *cb_data)
388 {
389         unsigned nr = array->nr, src, dst;
390         struct object_array_entry *objects = array->objects;
391
392         for (src = dst = 0; src < nr; src++) {
393                 if (want(&objects[src], cb_data)) {
394                         if (src != dst)
395                                 objects[dst] = objects[src];
396                         dst++;
397                 } else {
398                         object_array_release_entry(&objects[src]);
399                 }
400         }
401         array->nr = dst;
402 }
403
404 void object_array_clear(struct object_array *array)
405 {
406         int i;
407         for (i = 0; i < array->nr; i++)
408                 object_array_release_entry(&array->objects[i]);
409         FREE_AND_NULL(array->objects);
410         array->nr = array->alloc = 0;
411 }
412
413 /*
414  * Return true if array already contains an entry.
415  */
416 static int contains_object(struct object_array *array,
417                            const struct object *item, const char *name)
418 {
419         unsigned nr = array->nr, i;
420         struct object_array_entry *object = array->objects;
421
422         for (i = 0; i < nr; i++, object++)
423                 if (item == object->item && !strcmp(object->name, name))
424                         return 1;
425         return 0;
426 }
427
428 void object_array_remove_duplicates(struct object_array *array)
429 {
430         unsigned nr = array->nr, src;
431         struct object_array_entry *objects = array->objects;
432
433         array->nr = 0;
434         for (src = 0; src < nr; src++) {
435                 if (!contains_object(array, objects[src].item,
436                                      objects[src].name)) {
437                         if (src != array->nr)
438                                 objects[array->nr] = objects[src];
439                         array->nr++;
440                 } else {
441                         object_array_release_entry(&objects[src]);
442                 }
443         }
444 }
445
446 void clear_object_flags(unsigned flags)
447 {
448         int i;
449
450         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
451                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
452                 if (obj)
453                         obj->flags &= ~flags;
454         }
455 }
456
457 void repo_clear_commit_marks(struct repository *r, unsigned int flags)
458 {
459         int i;
460
461         for (i = 0; i < r->parsed_objects->obj_hash_size; i++) {
462                 struct object *obj = r->parsed_objects->obj_hash[i];
463                 if (obj && obj->type == OBJ_COMMIT)
464                         obj->flags &= ~flags;
465         }
466 }
467
468 struct parsed_object_pool *parsed_object_pool_new(void)
469 {
470         struct parsed_object_pool *o = xmalloc(sizeof(*o));
471         memset(o, 0, sizeof(*o));
472
473         o->blob_state = allocate_alloc_state();
474         o->tree_state = allocate_alloc_state();
475         o->commit_state = allocate_alloc_state();
476         o->tag_state = allocate_alloc_state();
477         o->object_state = allocate_alloc_state();
478
479         o->is_shallow = -1;
480         CALLOC_ARRAY(o->shallow_stat, 1);
481
482         o->buffer_slab = allocate_commit_buffer_slab();
483
484         return o;
485 }
486
487 struct raw_object_store *raw_object_store_new(void)
488 {
489         struct raw_object_store *o = xmalloc(sizeof(*o));
490
491         memset(o, 0, sizeof(*o));
492         INIT_LIST_HEAD(&o->packed_git_mru);
493         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
494         pthread_mutex_init(&o->replace_mutex, NULL);
495         return o;
496 }
497
498 static void free_object_directory(struct object_directory *odb)
499 {
500         free(odb->path);
501         odb_clear_loose_cache(odb);
502         free(odb);
503 }
504
505 static void free_object_directories(struct raw_object_store *o)
506 {
507         while (o->odb) {
508                 struct object_directory *next;
509
510                 next = o->odb->next;
511                 free_object_directory(o->odb);
512                 o->odb = next;
513         }
514 }
515
516 void raw_object_store_clear(struct raw_object_store *o)
517 {
518         FREE_AND_NULL(o->alternate_db);
519
520         oidmap_free(o->replace_map, 1);
521         FREE_AND_NULL(o->replace_map);
522         pthread_mutex_destroy(&o->replace_mutex);
523
524         free_commit_graph(o->commit_graph);
525         o->commit_graph = NULL;
526         o->commit_graph_attempted = 0;
527
528         free_object_directories(o);
529         o->odb_tail = NULL;
530         o->loaded_alternates = 0;
531
532         INIT_LIST_HEAD(&o->packed_git_mru);
533         close_object_store(o);
534         o->packed_git = NULL;
535
536         hashmap_clear(&o->pack_map);
537 }
538
539 void parsed_object_pool_clear(struct parsed_object_pool *o)
540 {
541         /*
542          * As objects are allocated in slabs (see alloc.c), we do
543          * not need to free each object, but each slab instead.
544          *
545          * Before doing so, we need to free any additional memory
546          * the objects may hold.
547          */
548         unsigned i;
549
550         for (i = 0; i < o->obj_hash_size; i++) {
551                 struct object *obj = o->obj_hash[i];
552
553                 if (!obj)
554                         continue;
555
556                 if (obj->type == OBJ_TREE)
557                         free_tree_buffer((struct tree*)obj);
558                 else if (obj->type == OBJ_COMMIT)
559                         release_commit_memory(o, (struct commit*)obj);
560                 else if (obj->type == OBJ_TAG)
561                         release_tag_memory((struct tag*)obj);
562         }
563
564         FREE_AND_NULL(o->obj_hash);
565         o->obj_hash_size = 0;
566
567         free_commit_buffer_slab(o->buffer_slab);
568         o->buffer_slab = NULL;
569
570         clear_alloc_state(o->blob_state);
571         clear_alloc_state(o->tree_state);
572         clear_alloc_state(o->commit_state);
573         clear_alloc_state(o->tag_state);
574         clear_alloc_state(o->object_state);
575         stat_validity_clear(o->shallow_stat);
576         FREE_AND_NULL(o->blob_state);
577         FREE_AND_NULL(o->tree_state);
578         FREE_AND_NULL(o->commit_state);
579         FREE_AND_NULL(o->tag_state);
580         FREE_AND_NULL(o->object_state);
581         FREE_AND_NULL(o->shallow_stat);
582 }