Merge branch 'rj/commit-slab-fix'
[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
8 static struct object **obj_hash;
9 static int nr_objs, obj_hash_size;
10
11 unsigned int get_max_object_index(void)
12 {
13         return obj_hash_size;
14 }
15
16 struct object *get_indexed_object(unsigned int idx)
17 {
18         return obj_hash[idx];
19 }
20
21 static const char *object_type_strings[] = {
22         NULL,           /* OBJ_NONE = 0 */
23         "commit",       /* OBJ_COMMIT = 1 */
24         "tree",         /* OBJ_TREE = 2 */
25         "blob",         /* OBJ_BLOB = 3 */
26         "tag",          /* OBJ_TAG = 4 */
27 };
28
29 const char *typename(unsigned int type)
30 {
31         if (type >= ARRAY_SIZE(object_type_strings))
32                 return NULL;
33         return object_type_strings[type];
34 }
35
36 int type_from_string(const char *str)
37 {
38         int i;
39
40         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
41                 if (!strcmp(str, object_type_strings[i]))
42                         return i;
43         die("invalid object type \"%s\"", str);
44 }
45
46 static unsigned int hash_obj(struct object *obj, unsigned int n)
47 {
48         unsigned int hash;
49         memcpy(&hash, obj->sha1, sizeof(unsigned int));
50         return hash % n;
51 }
52
53 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
54 {
55         unsigned int j = hash_obj(obj, size);
56
57         while (hash[j]) {
58                 j++;
59                 if (j >= size)
60                         j = 0;
61         }
62         hash[j] = obj;
63 }
64
65 static unsigned int hashtable_index(const unsigned char *sha1)
66 {
67         unsigned int i;
68         memcpy(&i, sha1, sizeof(unsigned int));
69         return i % obj_hash_size;
70 }
71
72 struct object *lookup_object(const unsigned char *sha1)
73 {
74         unsigned int i, first;
75         struct object *obj;
76
77         if (!obj_hash)
78                 return NULL;
79
80         first = i = hashtable_index(sha1);
81         while ((obj = obj_hash[i]) != NULL) {
82                 if (!hashcmp(sha1, obj->sha1))
83                         break;
84                 i++;
85                 if (i == obj_hash_size)
86                         i = 0;
87         }
88         if (obj && i != first) {
89                 /*
90                  * Move object to where we started to look for it so
91                  * that we do not need to walk the hash table the next
92                  * time we look for it.
93                  */
94                 struct object *tmp = obj_hash[i];
95                 obj_hash[i] = obj_hash[first];
96                 obj_hash[first] = tmp;
97         }
98         return obj;
99 }
100
101 static void grow_object_hash(void)
102 {
103         int i;
104         int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
105         struct object **new_hash;
106
107         new_hash = xcalloc(new_hash_size, sizeof(struct object *));
108         for (i = 0; i < obj_hash_size; i++) {
109                 struct object *obj = obj_hash[i];
110                 if (!obj)
111                         continue;
112                 insert_obj_hash(obj, new_hash, new_hash_size);
113         }
114         free(obj_hash);
115         obj_hash = new_hash;
116         obj_hash_size = new_hash_size;
117 }
118
119 void *create_object(const unsigned char *sha1, int type, void *o)
120 {
121         struct object *obj = o;
122
123         obj->parsed = 0;
124         obj->used = 0;
125         obj->type = type;
126         obj->flags = 0;
127         hashcpy(obj->sha1, sha1);
128
129         if (obj_hash_size - 1 <= nr_objs * 2)
130                 grow_object_hash();
131
132         insert_obj_hash(obj, obj_hash, obj_hash_size);
133         nr_objs++;
134         return obj;
135 }
136
137 struct object *lookup_unknown_object(const unsigned char *sha1)
138 {
139         struct object *obj = lookup_object(sha1);
140         if (!obj)
141                 obj = create_object(sha1, OBJ_NONE, alloc_object_node());
142         return obj;
143 }
144
145 struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
146 {
147         struct object *obj;
148         *eaten_p = 0;
149
150         obj = NULL;
151         if (type == OBJ_BLOB) {
152                 struct blob *blob = lookup_blob(sha1);
153                 if (blob) {
154                         if (parse_blob_buffer(blob, buffer, size))
155                                 return NULL;
156                         obj = &blob->object;
157                 }
158         } else if (type == OBJ_TREE) {
159                 struct tree *tree = lookup_tree(sha1);
160                 if (tree) {
161                         obj = &tree->object;
162                         if (!tree->buffer)
163                                 tree->object.parsed = 0;
164                         if (!tree->object.parsed) {
165                                 if (parse_tree_buffer(tree, buffer, size))
166                                         return NULL;
167                                 *eaten_p = 1;
168                         }
169                 }
170         } else if (type == OBJ_COMMIT) {
171                 struct commit *commit = lookup_commit(sha1);
172                 if (commit) {
173                         if (parse_commit_buffer(commit, buffer, size))
174                                 return NULL;
175                         if (!commit->buffer) {
176                                 commit->buffer = buffer;
177                                 *eaten_p = 1;
178                         }
179                         obj = &commit->object;
180                 }
181         } else if (type == OBJ_TAG) {
182                 struct tag *tag = lookup_tag(sha1);
183                 if (tag) {
184                         if (parse_tag_buffer(tag, buffer, size))
185                                return NULL;
186                         obj = &tag->object;
187                 }
188         } else {
189                 warning("object %s has unknown type id %d", sha1_to_hex(sha1), type);
190                 obj = NULL;
191         }
192         if (obj && obj->type == OBJ_NONE)
193                 obj->type = type;
194         return obj;
195 }
196
197 struct object *parse_object_or_die(const unsigned char *sha1,
198                                    const char *name)
199 {
200         struct object *o = parse_object(sha1);
201         if (o)
202                 return o;
203
204         die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1));
205 }
206
207 struct object *parse_object(const unsigned char *sha1)
208 {
209         unsigned long size;
210         enum object_type type;
211         int eaten;
212         const unsigned char *repl = lookup_replace_object(sha1);
213         void *buffer;
214         struct object *obj;
215
216         obj = lookup_object(sha1);
217         if (obj && obj->parsed)
218                 return obj;
219
220         if ((obj && obj->type == OBJ_BLOB) ||
221             (!obj && has_sha1_file(sha1) &&
222              sha1_object_info(sha1, NULL) == OBJ_BLOB)) {
223                 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
224                         error("sha1 mismatch %s", sha1_to_hex(repl));
225                         return NULL;
226                 }
227                 parse_blob_buffer(lookup_blob(sha1), NULL, 0);
228                 return lookup_object(sha1);
229         }
230
231         buffer = read_sha1_file(sha1, &type, &size);
232         if (buffer) {
233                 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
234                         free(buffer);
235                         error("sha1 mismatch %s", sha1_to_hex(repl));
236                         return NULL;
237                 }
238
239                 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
240                 if (!eaten)
241                         free(buffer);
242                 return obj;
243         }
244         return NULL;
245 }
246
247 struct object_list *object_list_insert(struct object *item,
248                                        struct object_list **list_p)
249 {
250         struct object_list *new_list = xmalloc(sizeof(struct object_list));
251         new_list->item = item;
252         new_list->next = *list_p;
253         *list_p = new_list;
254         return new_list;
255 }
256
257 int object_list_contains(struct object_list *list, struct object *obj)
258 {
259         while (list) {
260                 if (list->item == obj)
261                         return 1;
262                 list = list->next;
263         }
264         return 0;
265 }
266
267 void add_object_array(struct object *obj, const char *name, struct object_array *array)
268 {
269         add_object_array_with_mode(obj, name, array, S_IFINVALID);
270 }
271
272 /*
273  * A zero-length string to which object_array_entry::name can be
274  * initialized without requiring a malloc/free.
275  */
276 static char object_array_slopbuf[1];
277
278 void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
279 {
280         unsigned nr = array->nr;
281         unsigned alloc = array->alloc;
282         struct object_array_entry *objects = array->objects;
283         struct object_array_entry *entry;
284
285         if (nr >= alloc) {
286                 alloc = (alloc + 32) * 2;
287                 objects = xrealloc(objects, alloc * sizeof(*objects));
288                 array->alloc = alloc;
289                 array->objects = objects;
290         }
291         entry = &objects[nr];
292         entry->item = obj;
293         if (!name)
294                 entry->name = NULL;
295         else if (!*name)
296                 /* Use our own empty string instead of allocating one: */
297                 entry->name = object_array_slopbuf;
298         else
299                 entry->name = xstrdup(name);
300         entry->mode = mode;
301         array->nr = ++nr;
302 }
303
304 void object_array_filter(struct object_array *array,
305                          object_array_each_func_t want, void *cb_data)
306 {
307         unsigned nr = array->nr, src, dst;
308         struct object_array_entry *objects = array->objects;
309
310         for (src = dst = 0; src < nr; src++) {
311                 if (want(&objects[src], cb_data)) {
312                         if (src != dst)
313                                 objects[dst] = objects[src];
314                         dst++;
315                 } else {
316                         if (objects[src].name != object_array_slopbuf)
317                                 free(objects[src].name);
318                 }
319         }
320         array->nr = dst;
321 }
322
323 /*
324  * Return true iff array already contains an entry with name.
325  */
326 static int contains_name(struct object_array *array, const char *name)
327 {
328         unsigned nr = array->nr, i;
329         struct object_array_entry *object = array->objects;
330
331         for (i = 0; i < nr; i++, object++)
332                 if (!strcmp(object->name, name))
333                         return 1;
334         return 0;
335 }
336
337 void object_array_remove_duplicates(struct object_array *array)
338 {
339         unsigned nr = array->nr, src;
340         struct object_array_entry *objects = array->objects;
341
342         array->nr = 0;
343         for (src = 0; src < nr; src++) {
344                 if (!contains_name(array, objects[src].name)) {
345                         if (src != array->nr)
346                                 objects[array->nr] = objects[src];
347                         array->nr++;
348                 } else {
349                         if (objects[src].name != object_array_slopbuf)
350                                 free(objects[src].name);
351                 }
352         }
353 }
354
355 void clear_object_flags(unsigned flags)
356 {
357         int i;
358
359         for (i=0; i < obj_hash_size; i++) {
360                 struct object *obj = obj_hash[i];
361                 if (obj)
362                         obj->flags &= ~flags;
363         }
364 }