move setting of object->type to alloc_* functions
[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 /*
47 * Return a numerical hash value between 0 and n-1 for the object with
48 * the specified sha1. n must be a power of 2. Please note that the
49 * return value is *not* consistent across computer architectures.
50 */
51 static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
52 {
53 unsigned int hash;
54
55 /*
56 * Since the sha1 is essentially random, we just take the
57 * required number of bits directly from the first
58 * sizeof(unsigned int) bytes of sha1. First we have to copy
59 * the bytes into a properly aligned integer. If we cared
60 * about getting consistent results across architectures, we
61 * would have to call ntohl() here, too.
62 */
63 memcpy(&hash, sha1, sizeof(unsigned int));
64 return hash & (n - 1);
65 }
66
67 /*
68 * Insert obj into the hash table hash, which has length size (which
69 * must be a power of 2). On collisions, simply overflow to the next
70 * empty bucket.
71 */
72 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
73 {
74 unsigned int j = hash_obj(obj->sha1, size);
75
76 while (hash[j]) {
77 j++;
78 if (j >= size)
79 j = 0;
80 }
81 hash[j] = obj;
82 }
83
84 /*
85 * Look up the record for the given sha1 in the hash map stored in
86 * obj_hash. Return NULL if it was not found.
87 */
88 struct object *lookup_object(const unsigned char *sha1)
89 {
90 unsigned int i, first;
91 struct object *obj;
92
93 if (!obj_hash)
94 return NULL;
95
96 first = i = hash_obj(sha1, obj_hash_size);
97 while ((obj = obj_hash[i]) != NULL) {
98 if (!hashcmp(sha1, obj->sha1))
99 break;
100 i++;
101 if (i == obj_hash_size)
102 i = 0;
103 }
104 if (obj && i != first) {
105 /*
106 * Move object to where we started to look for it so
107 * that we do not need to walk the hash table the next
108 * time we look for it.
109 */
110 struct object *tmp = obj_hash[i];
111 obj_hash[i] = obj_hash[first];
112 obj_hash[first] = tmp;
113 }
114 return obj;
115 }
116
117 /*
118 * Increase the size of the hash map stored in obj_hash to the next
119 * power of 2 (but at least 32). Copy the existing values to the new
120 * hash map.
121 */
122 static void grow_object_hash(void)
123 {
124 int i;
125 /*
126 * Note that this size must always be power-of-2 to match hash_obj
127 * above.
128 */
129 int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
130 struct object **new_hash;
131
132 new_hash = xcalloc(new_hash_size, sizeof(struct object *));
133 for (i = 0; i < obj_hash_size; i++) {
134 struct object *obj = obj_hash[i];
135 if (!obj)
136 continue;
137 insert_obj_hash(obj, new_hash, new_hash_size);
138 }
139 free(obj_hash);
140 obj_hash = new_hash;
141 obj_hash_size = new_hash_size;
142 }
143
144 void *create_object(const unsigned char *sha1, void *o)
145 {
146 struct object *obj = o;
147
148 obj->parsed = 0;
149 obj->used = 0;
150 obj->flags = 0;
151 hashcpy(obj->sha1, sha1);
152
153 if (obj_hash_size - 1 <= nr_objs * 2)
154 grow_object_hash();
155
156 insert_obj_hash(obj, obj_hash, obj_hash_size);
157 nr_objs++;
158 return obj;
159 }
160
161 struct object *lookup_unknown_object(const unsigned char *sha1)
162 {
163 struct object *obj = lookup_object(sha1);
164 if (!obj)
165 obj = create_object(sha1, alloc_object_node());
166 return obj;
167 }
168
169 struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
170 {
171 struct object *obj;
172 *eaten_p = 0;
173
174 obj = NULL;
175 if (type == OBJ_BLOB) {
176 struct blob *blob = lookup_blob(sha1);
177 if (blob) {
178 if (parse_blob_buffer(blob, buffer, size))
179 return NULL;
180 obj = &blob->object;
181 }
182 } else if (type == OBJ_TREE) {
183 struct tree *tree = lookup_tree(sha1);
184 if (tree) {
185 obj = &tree->object;
186 if (!tree->buffer)
187 tree->object.parsed = 0;
188 if (!tree->object.parsed) {
189 if (parse_tree_buffer(tree, buffer, size))
190 return NULL;
191 *eaten_p = 1;
192 }
193 }
194 } else if (type == OBJ_COMMIT) {
195 struct commit *commit = lookup_commit(sha1);
196 if (commit) {
197 if (parse_commit_buffer(commit, buffer, size))
198 return NULL;
199 if (!get_cached_commit_buffer(commit, NULL)) {
200 set_commit_buffer(commit, buffer, size);
201 *eaten_p = 1;
202 }
203 obj = &commit->object;
204 }
205 } else if (type == OBJ_TAG) {
206 struct tag *tag = lookup_tag(sha1);
207 if (tag) {
208 if (parse_tag_buffer(tag, buffer, size))
209 return NULL;
210 obj = &tag->object;
211 }
212 } else {
213 warning("object %s has unknown type id %d", sha1_to_hex(sha1), type);
214 obj = NULL;
215 }
216 if (obj && obj->type == OBJ_NONE)
217 obj->type = type;
218 return obj;
219 }
220
221 struct object *parse_object_or_die(const unsigned char *sha1,
222 const char *name)
223 {
224 struct object *o = parse_object(sha1);
225 if (o)
226 return o;
227
228 die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1));
229 }
230
231 struct object *parse_object(const unsigned char *sha1)
232 {
233 unsigned long size;
234 enum object_type type;
235 int eaten;
236 const unsigned char *repl = lookup_replace_object(sha1);
237 void *buffer;
238 struct object *obj;
239
240 obj = lookup_object(sha1);
241 if (obj && obj->parsed)
242 return obj;
243
244 if ((obj && obj->type == OBJ_BLOB) ||
245 (!obj && has_sha1_file(sha1) &&
246 sha1_object_info(sha1, NULL) == OBJ_BLOB)) {
247 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
248 error("sha1 mismatch %s", sha1_to_hex(repl));
249 return NULL;
250 }
251 parse_blob_buffer(lookup_blob(sha1), NULL, 0);
252 return lookup_object(sha1);
253 }
254
255 buffer = read_sha1_file(sha1, &type, &size);
256 if (buffer) {
257 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
258 free(buffer);
259 error("sha1 mismatch %s", sha1_to_hex(repl));
260 return NULL;
261 }
262
263 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
264 if (!eaten)
265 free(buffer);
266 return obj;
267 }
268 return NULL;
269 }
270
271 struct object_list *object_list_insert(struct object *item,
272 struct object_list **list_p)
273 {
274 struct object_list *new_list = xmalloc(sizeof(struct object_list));
275 new_list->item = item;
276 new_list->next = *list_p;
277 *list_p = new_list;
278 return new_list;
279 }
280
281 int object_list_contains(struct object_list *list, struct object *obj)
282 {
283 while (list) {
284 if (list->item == obj)
285 return 1;
286 list = list->next;
287 }
288 return 0;
289 }
290
291 /*
292 * A zero-length string to which object_array_entry::name can be
293 * initialized without requiring a malloc/free.
294 */
295 static char object_array_slopbuf[1];
296
297 static void add_object_array_with_mode_context(struct object *obj, const char *name,
298 struct object_array *array,
299 unsigned mode,
300 struct object_context *context)
301 {
302 unsigned nr = array->nr;
303 unsigned alloc = array->alloc;
304 struct object_array_entry *objects = array->objects;
305 struct object_array_entry *entry;
306
307 if (nr >= alloc) {
308 alloc = (alloc + 32) * 2;
309 objects = xrealloc(objects, alloc * sizeof(*objects));
310 array->alloc = alloc;
311 array->objects = objects;
312 }
313 entry = &objects[nr];
314 entry->item = obj;
315 if (!name)
316 entry->name = NULL;
317 else if (!*name)
318 /* Use our own empty string instead of allocating one: */
319 entry->name = object_array_slopbuf;
320 else
321 entry->name = xstrdup(name);
322 entry->mode = mode;
323 entry->context = context;
324 array->nr = ++nr;
325 }
326
327 void add_object_array(struct object *obj, const char *name, struct object_array *array)
328 {
329 add_object_array_with_mode(obj, name, array, S_IFINVALID);
330 }
331
332 void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
333 {
334 add_object_array_with_mode_context(obj, name, array, mode, NULL);
335 }
336
337 void add_object_array_with_context(struct object *obj, const char *name, struct object_array *array, struct object_context *context)
338 {
339 if (context)
340 add_object_array_with_mode_context(obj, name, array, context->mode, context);
341 else
342 add_object_array_with_mode_context(obj, name, array, S_IFINVALID, context);
343 }
344
345 void object_array_filter(struct object_array *array,
346 object_array_each_func_t want, void *cb_data)
347 {
348 unsigned nr = array->nr, src, dst;
349 struct object_array_entry *objects = array->objects;
350
351 for (src = dst = 0; src < nr; src++) {
352 if (want(&objects[src], cb_data)) {
353 if (src != dst)
354 objects[dst] = objects[src];
355 dst++;
356 } else {
357 if (objects[src].name != object_array_slopbuf)
358 free(objects[src].name);
359 }
360 }
361 array->nr = dst;
362 }
363
364 /*
365 * Return true iff array already contains an entry with name.
366 */
367 static int contains_name(struct object_array *array, const char *name)
368 {
369 unsigned nr = array->nr, i;
370 struct object_array_entry *object = array->objects;
371
372 for (i = 0; i < nr; i++, object++)
373 if (!strcmp(object->name, name))
374 return 1;
375 return 0;
376 }
377
378 void object_array_remove_duplicates(struct object_array *array)
379 {
380 unsigned nr = array->nr, src;
381 struct object_array_entry *objects = array->objects;
382
383 array->nr = 0;
384 for (src = 0; src < nr; src++) {
385 if (!contains_name(array, objects[src].name)) {
386 if (src != array->nr)
387 objects[array->nr] = objects[src];
388 array->nr++;
389 } else {
390 if (objects[src].name != object_array_slopbuf)
391 free(objects[src].name);
392 }
393 }
394 }
395
396 void clear_object_flags(unsigned flags)
397 {
398 int i;
399
400 for (i=0; i < obj_hash_size; i++) {
401 struct object *obj = obj_hash[i];
402 if (obj)
403 obj->flags &= ~flags;
404 }
405 }