Merge branch 'es/doc-mentoring'
[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         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 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 repository *r, 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(r, (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(const struct object_id *oid)
181 {
182         struct object *obj = lookup_object(the_repository, oid);
183         if (!obj)
184                 obj = create_object(the_repository, oid,
185                                     alloc_object_node(the_repository));
186         return obj;
187 }
188
189 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)
190 {
191         struct object *obj;
192         *eaten_p = 0;
193
194         obj = NULL;
195         if (type == OBJ_BLOB) {
196                 struct blob *blob = lookup_blob(r, oid);
197                 if (blob) {
198                         if (parse_blob_buffer(blob, buffer, size))
199                                 return NULL;
200                         obj = &blob->object;
201                 }
202         } else if (type == OBJ_TREE) {
203                 struct tree *tree = lookup_tree(r, oid);
204                 if (tree) {
205                         obj = &tree->object;
206                         if (!tree->buffer)
207                                 tree->object.parsed = 0;
208                         if (!tree->object.parsed) {
209                                 if (parse_tree_buffer(tree, buffer, size))
210                                         return NULL;
211                                 *eaten_p = 1;
212                         }
213                 }
214         } else if (type == OBJ_COMMIT) {
215                 struct commit *commit = lookup_commit(r, oid);
216                 if (commit) {
217                         if (parse_commit_buffer(r, commit, buffer, size, 1))
218                                 return NULL;
219                         if (!get_cached_commit_buffer(r, commit, NULL)) {
220                                 set_commit_buffer(r, commit, buffer, size);
221                                 *eaten_p = 1;
222                         }
223                         obj = &commit->object;
224                 }
225         } else if (type == OBJ_TAG) {
226                 struct tag *tag = lookup_tag(r, oid);
227                 if (tag) {
228                         if (parse_tag_buffer(r, tag, buffer, size))
229                                return NULL;
230                         obj = &tag->object;
231                 }
232         } else {
233                 warning(_("object %s has unknown type id %d"), oid_to_hex(oid), type);
234                 obj = NULL;
235         }
236         return obj;
237 }
238
239 struct object *parse_object_or_die(const struct object_id *oid,
240                                    const char *name)
241 {
242         struct object *o = parse_object(the_repository, oid);
243         if (o)
244                 return o;
245
246         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
247 }
248
249 struct object *parse_object(struct repository *r, const struct object_id *oid)
250 {
251         unsigned long size;
252         enum object_type type;
253         int eaten;
254         const struct object_id *repl = lookup_replace_object(r, oid);
255         void *buffer;
256         struct object *obj;
257
258         obj = lookup_object(r, oid);
259         if (obj && obj->parsed)
260                 return obj;
261
262         if ((obj && obj->type == OBJ_BLOB && repo_has_object_file(r, oid)) ||
263             (!obj && repo_has_object_file(r, oid) &&
264              oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
265                 if (check_object_signature(r, repl, NULL, 0, NULL) < 0) {
266                         error(_("hash mismatch %s"), oid_to_hex(oid));
267                         return NULL;
268                 }
269                 parse_blob_buffer(lookup_blob(r, oid), NULL, 0);
270                 return lookup_object(r, oid);
271         }
272
273         buffer = repo_read_object_file(r, oid, &type, &size);
274         if (buffer) {
275                 if (check_object_signature(r, repl, buffer, size,
276                                            type_name(type)) < 0) {
277                         free(buffer);
278                         error(_("hash mismatch %s"), oid_to_hex(repl));
279                         return NULL;
280                 }
281
282                 obj = parse_object_buffer(r, oid, type, size,
283                                           buffer, &eaten);
284                 if (!eaten)
285                         free(buffer);
286                 return obj;
287         }
288         return NULL;
289 }
290
291 struct object_list *object_list_insert(struct object *item,
292                                        struct object_list **list_p)
293 {
294         struct object_list *new_list = xmalloc(sizeof(struct object_list));
295         new_list->item = item;
296         new_list->next = *list_p;
297         *list_p = new_list;
298         return new_list;
299 }
300
301 int object_list_contains(struct object_list *list, struct object *obj)
302 {
303         while (list) {
304                 if (list->item == obj)
305                         return 1;
306                 list = list->next;
307         }
308         return 0;
309 }
310
311 /*
312  * A zero-length string to which object_array_entry::name can be
313  * initialized without requiring a malloc/free.
314  */
315 static char object_array_slopbuf[1];
316
317 void add_object_array_with_path(struct object *obj, const char *name,
318                                 struct object_array *array,
319                                 unsigned mode, const char *path)
320 {
321         unsigned nr = array->nr;
322         unsigned alloc = array->alloc;
323         struct object_array_entry *objects = array->objects;
324         struct object_array_entry *entry;
325
326         if (nr >= alloc) {
327                 alloc = (alloc + 32) * 2;
328                 REALLOC_ARRAY(objects, alloc);
329                 array->alloc = alloc;
330                 array->objects = objects;
331         }
332         entry = &objects[nr];
333         entry->item = obj;
334         if (!name)
335                 entry->name = NULL;
336         else if (!*name)
337                 /* Use our own empty string instead of allocating one: */
338                 entry->name = object_array_slopbuf;
339         else
340                 entry->name = xstrdup(name);
341         entry->mode = mode;
342         if (path)
343                 entry->path = xstrdup(path);
344         else
345                 entry->path = NULL;
346         array->nr = ++nr;
347 }
348
349 void add_object_array(struct object *obj, const char *name, struct object_array *array)
350 {
351         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
352 }
353
354 /*
355  * Free all memory associated with an entry; the result is
356  * in an unspecified state and should not be examined.
357  */
358 static void object_array_release_entry(struct object_array_entry *ent)
359 {
360         if (ent->name != object_array_slopbuf)
361                 free(ent->name);
362         free(ent->path);
363 }
364
365 struct object *object_array_pop(struct object_array *array)
366 {
367         struct object *ret;
368
369         if (!array->nr)
370                 return NULL;
371
372         ret = array->objects[array->nr - 1].item;
373         object_array_release_entry(&array->objects[array->nr - 1]);
374         array->nr--;
375         return ret;
376 }
377
378 void object_array_filter(struct object_array *array,
379                          object_array_each_func_t want, void *cb_data)
380 {
381         unsigned nr = array->nr, src, dst;
382         struct object_array_entry *objects = array->objects;
383
384         for (src = dst = 0; src < nr; src++) {
385                 if (want(&objects[src], cb_data)) {
386                         if (src != dst)
387                                 objects[dst] = objects[src];
388                         dst++;
389                 } else {
390                         object_array_release_entry(&objects[src]);
391                 }
392         }
393         array->nr = dst;
394 }
395
396 void object_array_clear(struct object_array *array)
397 {
398         int i;
399         for (i = 0; i < array->nr; i++)
400                 object_array_release_entry(&array->objects[i]);
401         FREE_AND_NULL(array->objects);
402         array->nr = array->alloc = 0;
403 }
404
405 /*
406  * Return true iff array already contains an entry with name.
407  */
408 static int contains_name(struct object_array *array, const char *name)
409 {
410         unsigned nr = array->nr, i;
411         struct object_array_entry *object = array->objects;
412
413         for (i = 0; i < nr; i++, object++)
414                 if (!strcmp(object->name, name))
415                         return 1;
416         return 0;
417 }
418
419 void object_array_remove_duplicates(struct object_array *array)
420 {
421         unsigned nr = array->nr, src;
422         struct object_array_entry *objects = array->objects;
423
424         array->nr = 0;
425         for (src = 0; src < nr; src++) {
426                 if (!contains_name(array, objects[src].name)) {
427                         if (src != array->nr)
428                                 objects[array->nr] = objects[src];
429                         array->nr++;
430                 } else {
431                         object_array_release_entry(&objects[src]);
432                 }
433         }
434 }
435
436 void clear_object_flags(unsigned flags)
437 {
438         int i;
439
440         for (i=0; i < the_repository->parsed_objects->obj_hash_size; i++) {
441                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
442                 if (obj)
443                         obj->flags &= ~flags;
444         }
445 }
446
447 void clear_commit_marks_all(unsigned int flags)
448 {
449         int i;
450
451         for (i = 0; i < the_repository->parsed_objects->obj_hash_size; i++) {
452                 struct object *obj = the_repository->parsed_objects->obj_hash[i];
453                 if (obj && obj->type == OBJ_COMMIT)
454                         obj->flags &= ~flags;
455         }
456 }
457
458 struct parsed_object_pool *parsed_object_pool_new(void)
459 {
460         struct parsed_object_pool *o = xmalloc(sizeof(*o));
461         memset(o, 0, sizeof(*o));
462
463         o->blob_state = allocate_alloc_state();
464         o->tree_state = allocate_alloc_state();
465         o->commit_state = allocate_alloc_state();
466         o->tag_state = allocate_alloc_state();
467         o->object_state = allocate_alloc_state();
468
469         o->is_shallow = -1;
470         o->shallow_stat = xcalloc(1, sizeof(*o->shallow_stat));
471
472         o->buffer_slab = allocate_commit_buffer_slab();
473
474         return o;
475 }
476
477 struct raw_object_store *raw_object_store_new(void)
478 {
479         struct raw_object_store *o = xmalloc(sizeof(*o));
480
481         memset(o, 0, sizeof(*o));
482         INIT_LIST_HEAD(&o->packed_git_mru);
483         hashmap_init(&o->pack_map, pack_map_entry_cmp, NULL, 0);
484         pthread_mutex_init(&o->replace_mutex, NULL);
485         return o;
486 }
487
488 static void free_object_directory(struct object_directory *odb)
489 {
490         free(odb->path);
491         odb_clear_loose_cache(odb);
492         free(odb);
493 }
494
495 static void free_object_directories(struct raw_object_store *o)
496 {
497         while (o->odb) {
498                 struct object_directory *next;
499
500                 next = o->odb->next;
501                 free_object_directory(o->odb);
502                 o->odb = next;
503         }
504 }
505
506 void raw_object_store_clear(struct raw_object_store *o)
507 {
508         FREE_AND_NULL(o->alternate_db);
509
510         oidmap_free(o->replace_map, 1);
511         FREE_AND_NULL(o->replace_map);
512         pthread_mutex_destroy(&o->replace_mutex);
513
514         free_commit_graph(o->commit_graph);
515         o->commit_graph = NULL;
516         o->commit_graph_attempted = 0;
517
518         free_object_directories(o);
519         o->odb_tail = NULL;
520         o->loaded_alternates = 0;
521
522         INIT_LIST_HEAD(&o->packed_git_mru);
523         close_object_store(o);
524         o->packed_git = NULL;
525
526         hashmap_free(&o->pack_map);
527 }
528
529 void parsed_object_pool_clear(struct parsed_object_pool *o)
530 {
531         /*
532          * As objects are allocated in slabs (see alloc.c), we do
533          * not need to free each object, but each slab instead.
534          *
535          * Before doing so, we need to free any additional memory
536          * the objects may hold.
537          */
538         unsigned i;
539
540         for (i = 0; i < o->obj_hash_size; i++) {
541                 struct object *obj = o->obj_hash[i];
542
543                 if (!obj)
544                         continue;
545
546                 if (obj->type == OBJ_TREE)
547                         free_tree_buffer((struct tree*)obj);
548                 else if (obj->type == OBJ_COMMIT)
549                         release_commit_memory(o, (struct commit*)obj);
550                 else if (obj->type == OBJ_TAG)
551                         release_tag_memory((struct tag*)obj);
552         }
553
554         FREE_AND_NULL(o->obj_hash);
555         o->obj_hash_size = 0;
556
557         free_commit_buffer_slab(o->buffer_slab);
558         o->buffer_slab = NULL;
559
560         clear_alloc_state(o->blob_state);
561         clear_alloc_state(o->tree_state);
562         clear_alloc_state(o->commit_state);
563         clear_alloc_state(o->tag_state);
564         clear_alloc_state(o->object_state);
565         stat_validity_clear(o->shallow_stat);
566         FREE_AND_NULL(o->blob_state);
567         FREE_AND_NULL(o->tree_state);
568         FREE_AND_NULL(o->commit_state);
569         FREE_AND_NULL(o->tag_state);
570         FREE_AND_NULL(o->object_state);
571         FREE_AND_NULL(o->shallow_stat);
572 }