Merge branch 'sb/parse-object-buffer-eaten'
[git/git.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 }