Merge branch 'js/rerere-forget-protect-against-NUL' into maint
[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;
75         struct object *obj;
76
77         if (!obj_hash)
78                 return NULL;
79
80         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         return obj;
89 }
90
91 static void grow_object_hash(void)
92 {
93         int i;
94         int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
95         struct object **new_hash;
96
97         new_hash = xcalloc(new_hash_size, sizeof(struct object *));
98         for (i = 0; i < obj_hash_size; i++) {
99                 struct object *obj = obj_hash[i];
100                 if (!obj)
101                         continue;
102                 insert_obj_hash(obj, new_hash, new_hash_size);
103         }
104         free(obj_hash);
105         obj_hash = new_hash;
106         obj_hash_size = new_hash_size;
107 }
108
109 void *create_object(const unsigned char *sha1, int type, void *o)
110 {
111         struct object *obj = o;
112
113         obj->parsed = 0;
114         obj->used = 0;
115         obj->type = type;
116         obj->flags = 0;
117         hashcpy(obj->sha1, sha1);
118
119         if (obj_hash_size - 1 <= nr_objs * 2)
120                 grow_object_hash();
121
122         insert_obj_hash(obj, obj_hash, obj_hash_size);
123         nr_objs++;
124         return obj;
125 }
126
127 struct object *lookup_unknown_object(const unsigned char *sha1)
128 {
129         struct object *obj = lookup_object(sha1);
130         if (!obj)
131                 obj = create_object(sha1, OBJ_NONE, alloc_object_node());
132         return obj;
133 }
134
135 struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
136 {
137         struct object *obj;
138         int eaten = 0;
139
140         obj = NULL;
141         if (type == OBJ_BLOB) {
142                 struct blob *blob = lookup_blob(sha1);
143                 if (blob) {
144                         if (parse_blob_buffer(blob, buffer, size))
145                                 return NULL;
146                         obj = &blob->object;
147                 }
148         } else if (type == OBJ_TREE) {
149                 struct tree *tree = lookup_tree(sha1);
150                 if (tree) {
151                         obj = &tree->object;
152                         if (!tree->buffer)
153                                 tree->object.parsed = 0;
154                         if (!tree->object.parsed) {
155                                 if (parse_tree_buffer(tree, buffer, size))
156                                         return NULL;
157                                 eaten = 1;
158                         }
159                 }
160         } else if (type == OBJ_COMMIT) {
161                 struct commit *commit = lookup_commit(sha1);
162                 if (commit) {
163                         if (parse_commit_buffer(commit, buffer, size))
164                                 return NULL;
165                         if (!commit->buffer) {
166                                 commit->buffer = buffer;
167                                 eaten = 1;
168                         }
169                         obj = &commit->object;
170                 }
171         } else if (type == OBJ_TAG) {
172                 struct tag *tag = lookup_tag(sha1);
173                 if (tag) {
174                         if (parse_tag_buffer(tag, buffer, size))
175                                return NULL;
176                         obj = &tag->object;
177                 }
178         } else {
179                 warning("object %s has unknown type id %d", sha1_to_hex(sha1), type);
180                 obj = NULL;
181         }
182         if (obj && obj->type == OBJ_NONE)
183                 obj->type = type;
184         *eaten_p = eaten;
185         return obj;
186 }
187
188 struct object *parse_object_or_die(const unsigned char *sha1,
189                                    const char *name)
190 {
191         struct object *o = parse_object(sha1);
192         if (o)
193                 return o;
194
195         die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1));
196 }
197
198 struct object *parse_object(const unsigned char *sha1)
199 {
200         unsigned long size;
201         enum object_type type;
202         int eaten;
203         const unsigned char *repl = lookup_replace_object(sha1);
204         void *buffer;
205         struct object *obj;
206
207         obj = lookup_object(sha1);
208         if (obj && obj->parsed)
209                 return obj;
210
211         if ((obj && obj->type == OBJ_BLOB) ||
212             (!obj && has_sha1_file(sha1) &&
213              sha1_object_info(sha1, NULL) == OBJ_BLOB)) {
214                 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
215                         error("sha1 mismatch %s", sha1_to_hex(repl));
216                         return NULL;
217                 }
218                 parse_blob_buffer(lookup_blob(sha1), NULL, 0);
219                 return lookup_object(sha1);
220         }
221
222         buffer = read_sha1_file(sha1, &type, &size);
223         if (buffer) {
224                 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
225                         free(buffer);
226                         error("sha1 mismatch %s", sha1_to_hex(repl));
227                         return NULL;
228                 }
229
230                 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
231                 if (!eaten)
232                         free(buffer);
233                 return obj;
234         }
235         return NULL;
236 }
237
238 struct object_list *object_list_insert(struct object *item,
239                                        struct object_list **list_p)
240 {
241         struct object_list *new_list = xmalloc(sizeof(struct object_list));
242         new_list->item = item;
243         new_list->next = *list_p;
244         *list_p = new_list;
245         return new_list;
246 }
247
248 int object_list_contains(struct object_list *list, struct object *obj)
249 {
250         while (list) {
251                 if (list->item == obj)
252                         return 1;
253                 list = list->next;
254         }
255         return 0;
256 }
257
258 void add_object_array(struct object *obj, const char *name, struct object_array *array)
259 {
260         add_object_array_with_mode(obj, name, array, S_IFINVALID);
261 }
262
263 void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
264 {
265         unsigned nr = array->nr;
266         unsigned alloc = array->alloc;
267         struct object_array_entry *objects = array->objects;
268
269         if (nr >= alloc) {
270                 alloc = (alloc + 32) * 2;
271                 objects = xrealloc(objects, alloc * sizeof(*objects));
272                 array->alloc = alloc;
273                 array->objects = objects;
274         }
275         objects[nr].item = obj;
276         objects[nr].name = name;
277         objects[nr].mode = mode;
278         array->nr = ++nr;
279 }
280
281 void object_array_remove_duplicates(struct object_array *array)
282 {
283         unsigned int ref, src, dst;
284         struct object_array_entry *objects = array->objects;
285
286         for (ref = 0; ref + 1 < array->nr; ref++) {
287                 for (src = ref + 1, dst = src;
288                      src < array->nr;
289                      src++) {
290                         if (!strcmp(objects[ref].name, objects[src].name))
291                                 continue;
292                         if (src != dst)
293                                 objects[dst] = objects[src];
294                         dst++;
295                 }
296                 array->nr = dst;
297         }
298 }
299
300 void clear_object_flags(unsigned flags)
301 {
302         int i;
303
304         for (i=0; i < obj_hash_size; i++) {
305                 struct object *obj = obj_hash[i];
306                 if (obj)
307                         obj->flags &= ~flags;
308         }
309 }