Merge branch 'ps/test-chmtime-get'
[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 #include "packfile.h"
9
10 static struct object **obj_hash;
11 static int nr_objs, obj_hash_size;
12
13 unsigned int get_max_object_index(void)
14 {
15         return obj_hash_size;
16 }
17
18 struct object *get_indexed_object(unsigned int idx)
19 {
20         return 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 unsigned char *sha1, unsigned int n)
62 {
63         return sha1hash(sha1) & (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.hash, 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(const unsigned char *sha1)
88 {
89         unsigned int i, first;
90         struct object *obj;
91
92         if (!obj_hash)
93                 return NULL;
94
95         first = i = hash_obj(sha1, obj_hash_size);
96         while ((obj = obj_hash[i]) != NULL) {
97                 if (!hashcmp(sha1, obj->oid.hash))
98                         break;
99                 i++;
100                 if (i == 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(obj_hash[i], obj_hash[first]);
110         }
111         return obj;
112 }
113
114 /*
115  * Increase the size of the hash map stored in obj_hash to the next
116  * power of 2 (but at least 32).  Copy the existing values to the new
117  * hash map.
118  */
119 static void grow_object_hash(void)
120 {
121         int i;
122         /*
123          * Note that this size must always be power-of-2 to match hash_obj
124          * above.
125          */
126         int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
127         struct object **new_hash;
128
129         new_hash = xcalloc(new_hash_size, sizeof(struct object *));
130         for (i = 0; i < obj_hash_size; i++) {
131                 struct object *obj = obj_hash[i];
132                 if (!obj)
133                         continue;
134                 insert_obj_hash(obj, new_hash, new_hash_size);
135         }
136         free(obj_hash);
137         obj_hash = new_hash;
138         obj_hash_size = new_hash_size;
139 }
140
141 void *create_object(const unsigned char *sha1, void *o)
142 {
143         struct object *obj = o;
144
145         obj->parsed = 0;
146         obj->flags = 0;
147         hashcpy(obj->oid.hash, sha1);
148
149         if (obj_hash_size - 1 <= nr_objs * 2)
150                 grow_object_hash();
151
152         insert_obj_hash(obj, obj_hash, obj_hash_size);
153         nr_objs++;
154         return obj;
155 }
156
157 void *object_as_type(struct object *obj, enum object_type type, int quiet)
158 {
159         if (obj->type == type)
160                 return obj;
161         else if (obj->type == OBJ_NONE) {
162                 if (type == OBJ_COMMIT)
163                         ((struct commit *)obj)->index = alloc_commit_index();
164                 obj->type = type;
165                 return obj;
166         }
167         else {
168                 if (!quiet)
169                         error("object %s is a %s, not a %s",
170                               oid_to_hex(&obj->oid),
171                               type_name(obj->type), type_name(type));
172                 return NULL;
173         }
174 }
175
176 struct object *lookup_unknown_object(const unsigned char *sha1)
177 {
178         struct object *obj = lookup_object(sha1);
179         if (!obj)
180                 obj = create_object(sha1, alloc_object_node());
181         return obj;
182 }
183
184 struct object *parse_object_buffer(const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
185 {
186         struct object *obj;
187         *eaten_p = 0;
188
189         obj = NULL;
190         if (type == OBJ_BLOB) {
191                 struct blob *blob = lookup_blob(oid);
192                 if (blob) {
193                         if (parse_blob_buffer(blob, buffer, size))
194                                 return NULL;
195                         obj = &blob->object;
196                 }
197         } else if (type == OBJ_TREE) {
198                 struct tree *tree = lookup_tree(oid);
199                 if (tree) {
200                         obj = &tree->object;
201                         if (!tree->buffer)
202                                 tree->object.parsed = 0;
203                         if (!tree->object.parsed) {
204                                 if (parse_tree_buffer(tree, buffer, size))
205                                         return NULL;
206                                 *eaten_p = 1;
207                         }
208                 }
209         } else if (type == OBJ_COMMIT) {
210                 struct commit *commit = lookup_commit(oid);
211                 if (commit) {
212                         if (parse_commit_buffer(commit, buffer, size))
213                                 return NULL;
214                         if (!get_cached_commit_buffer(commit, NULL)) {
215                                 set_commit_buffer(commit, buffer, size);
216                                 *eaten_p = 1;
217                         }
218                         obj = &commit->object;
219                 }
220         } else if (type == OBJ_TAG) {
221                 struct tag *tag = lookup_tag(oid);
222                 if (tag) {
223                         if (parse_tag_buffer(tag, buffer, size))
224                                return NULL;
225                         obj = &tag->object;
226                 }
227         } else {
228                 warning("object %s has unknown type id %d", oid_to_hex(oid), type);
229                 obj = NULL;
230         }
231         return obj;
232 }
233
234 struct object *parse_object_or_die(const struct object_id *oid,
235                                    const char *name)
236 {
237         struct object *o = parse_object(oid);
238         if (o)
239                 return o;
240
241         die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
242 }
243
244 struct object *parse_object(const struct object_id *oid)
245 {
246         unsigned long size;
247         enum object_type type;
248         int eaten;
249         const struct object_id *repl = lookup_replace_object(oid);
250         void *buffer;
251         struct object *obj;
252
253         obj = lookup_object(oid->hash);
254         if (obj && obj->parsed)
255                 return obj;
256
257         if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
258             (!obj && has_object_file(oid) &&
259              oid_object_info(oid, NULL) == OBJ_BLOB)) {
260                 if (check_object_signature(repl, NULL, 0, NULL) < 0) {
261                         error("sha1 mismatch %s", oid_to_hex(oid));
262                         return NULL;
263                 }
264                 parse_blob_buffer(lookup_blob(oid), NULL, 0);
265                 return lookup_object(oid->hash);
266         }
267
268         buffer = read_object_file(oid, &type, &size);
269         if (buffer) {
270                 if (check_object_signature(repl, buffer, size, type_name(type)) < 0) {
271                         free(buffer);
272                         error("sha1 mismatch %s", oid_to_hex(repl));
273                         return NULL;
274                 }
275
276                 obj = parse_object_buffer(oid, type, size, buffer, &eaten);
277                 if (!eaten)
278                         free(buffer);
279                 return obj;
280         }
281         return NULL;
282 }
283
284 struct object_list *object_list_insert(struct object *item,
285                                        struct object_list **list_p)
286 {
287         struct object_list *new_list = xmalloc(sizeof(struct object_list));
288         new_list->item = item;
289         new_list->next = *list_p;
290         *list_p = new_list;
291         return new_list;
292 }
293
294 int object_list_contains(struct object_list *list, struct object *obj)
295 {
296         while (list) {
297                 if (list->item == obj)
298                         return 1;
299                 list = list->next;
300         }
301         return 0;
302 }
303
304 /*
305  * A zero-length string to which object_array_entry::name can be
306  * initialized without requiring a malloc/free.
307  */
308 static char object_array_slopbuf[1];
309
310 void add_object_array_with_path(struct object *obj, const char *name,
311                                 struct object_array *array,
312                                 unsigned mode, const char *path)
313 {
314         unsigned nr = array->nr;
315         unsigned alloc = array->alloc;
316         struct object_array_entry *objects = array->objects;
317         struct object_array_entry *entry;
318
319         if (nr >= alloc) {
320                 alloc = (alloc + 32) * 2;
321                 REALLOC_ARRAY(objects, alloc);
322                 array->alloc = alloc;
323                 array->objects = objects;
324         }
325         entry = &objects[nr];
326         entry->item = obj;
327         if (!name)
328                 entry->name = NULL;
329         else if (!*name)
330                 /* Use our own empty string instead of allocating one: */
331                 entry->name = object_array_slopbuf;
332         else
333                 entry->name = xstrdup(name);
334         entry->mode = mode;
335         if (path)
336                 entry->path = xstrdup(path);
337         else
338                 entry->path = NULL;
339         array->nr = ++nr;
340 }
341
342 void add_object_array(struct object *obj, const char *name, struct object_array *array)
343 {
344         add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
345 }
346
347 /*
348  * Free all memory associated with an entry; the result is
349  * in an unspecified state and should not be examined.
350  */
351 static void object_array_release_entry(struct object_array_entry *ent)
352 {
353         if (ent->name != object_array_slopbuf)
354                 free(ent->name);
355         free(ent->path);
356 }
357
358 struct object *object_array_pop(struct object_array *array)
359 {
360         struct object *ret;
361
362         if (!array->nr)
363                 return NULL;
364
365         ret = array->objects[array->nr - 1].item;
366         object_array_release_entry(&array->objects[array->nr - 1]);
367         array->nr--;
368         return ret;
369 }
370
371 void object_array_filter(struct object_array *array,
372                          object_array_each_func_t want, void *cb_data)
373 {
374         unsigned nr = array->nr, src, dst;
375         struct object_array_entry *objects = array->objects;
376
377         for (src = dst = 0; src < nr; src++) {
378                 if (want(&objects[src], cb_data)) {
379                         if (src != dst)
380                                 objects[dst] = objects[src];
381                         dst++;
382                 } else {
383                         object_array_release_entry(&objects[src]);
384                 }
385         }
386         array->nr = dst;
387 }
388
389 void object_array_clear(struct object_array *array)
390 {
391         int i;
392         for (i = 0; i < array->nr; i++)
393                 object_array_release_entry(&array->objects[i]);
394         FREE_AND_NULL(array->objects);
395         array->nr = array->alloc = 0;
396 }
397
398 /*
399  * Return true iff array already contains an entry with name.
400  */
401 static int contains_name(struct object_array *array, const char *name)
402 {
403         unsigned nr = array->nr, i;
404         struct object_array_entry *object = array->objects;
405
406         for (i = 0; i < nr; i++, object++)
407                 if (!strcmp(object->name, name))
408                         return 1;
409         return 0;
410 }
411
412 void object_array_remove_duplicates(struct object_array *array)
413 {
414         unsigned nr = array->nr, src;
415         struct object_array_entry *objects = array->objects;
416
417         array->nr = 0;
418         for (src = 0; src < nr; src++) {
419                 if (!contains_name(array, objects[src].name)) {
420                         if (src != array->nr)
421                                 objects[array->nr] = objects[src];
422                         array->nr++;
423                 } else {
424                         object_array_release_entry(&objects[src]);
425                 }
426         }
427 }
428
429 void clear_object_flags(unsigned flags)
430 {
431         int i;
432
433         for (i=0; i < obj_hash_size; i++) {
434                 struct object *obj = obj_hash[i];
435                 if (obj)
436                         obj->flags &= ~flags;
437         }
438 }
439
440 void clear_commit_marks_all(unsigned int flags)
441 {
442         int i;
443
444         for (i = 0; i < obj_hash_size; i++) {
445                 struct object *obj = obj_hash[i];
446                 if (obj && obj->type == OBJ_COMMIT)
447                         obj->flags &= ~flags;
448         }
449 }
450
451 struct raw_object_store *raw_object_store_new(void)
452 {
453         struct raw_object_store *o = xmalloc(sizeof(*o));
454
455         memset(o, 0, sizeof(*o));
456         INIT_LIST_HEAD(&o->packed_git_mru);
457         return o;
458 }
459
460 static void free_alt_odb(struct alternate_object_database *alt)
461 {
462         strbuf_release(&alt->scratch);
463         oid_array_clear(&alt->loose_objects_cache);
464         free(alt);
465 }
466
467 static void free_alt_odbs(struct raw_object_store *o)
468 {
469         while (o->alt_odb_list) {
470                 struct alternate_object_database *next;
471
472                 next = o->alt_odb_list->next;
473                 free_alt_odb(o->alt_odb_list);
474                 o->alt_odb_list = next;
475         }
476 }
477
478 void raw_object_store_clear(struct raw_object_store *o)
479 {
480         FREE_AND_NULL(o->objectdir);
481         FREE_AND_NULL(o->alternate_db);
482
483         free_alt_odbs(o);
484         o->alt_odb_tail = NULL;
485
486         INIT_LIST_HEAD(&o->packed_git_mru);
487         close_all_packs(o);
488         o->packed_git = NULL;
489 }