parse_object_buffer: do not set object type
[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 return obj;
217 }
218
219 struct object *parse_object_or_die(const unsigned char *sha1,
220 const char *name)
221 {
222 struct object *o = parse_object(sha1);
223 if (o)
224 return o;
225
226 die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1));
227 }
228
229 struct object *parse_object(const unsigned char *sha1)
230 {
231 unsigned long size;
232 enum object_type type;
233 int eaten;
234 const unsigned char *repl = lookup_replace_object(sha1);
235 void *buffer;
236 struct object *obj;
237
238 obj = lookup_object(sha1);
239 if (obj && obj->parsed)
240 return obj;
241
242 if ((obj && obj->type == OBJ_BLOB) ||
243 (!obj && has_sha1_file(sha1) &&
244 sha1_object_info(sha1, NULL) == OBJ_BLOB)) {
245 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
246 error("sha1 mismatch %s", sha1_to_hex(repl));
247 return NULL;
248 }
249 parse_blob_buffer(lookup_blob(sha1), NULL, 0);
250 return lookup_object(sha1);
251 }
252
253 buffer = read_sha1_file(sha1, &type, &size);
254 if (buffer) {
255 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
256 free(buffer);
257 error("sha1 mismatch %s", sha1_to_hex(repl));
258 return NULL;
259 }
260
261 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
262 if (!eaten)
263 free(buffer);
264 return obj;
265 }
266 return NULL;
267 }
268
269 struct object_list *object_list_insert(struct object *item,
270 struct object_list **list_p)
271 {
272 struct object_list *new_list = xmalloc(sizeof(struct object_list));
273 new_list->item = item;
274 new_list->next = *list_p;
275 *list_p = new_list;
276 return new_list;
277 }
278
279 int object_list_contains(struct object_list *list, struct object *obj)
280 {
281 while (list) {
282 if (list->item == obj)
283 return 1;
284 list = list->next;
285 }
286 return 0;
287 }
288
289 /*
290 * A zero-length string to which object_array_entry::name can be
291 * initialized without requiring a malloc/free.
292 */
293 static char object_array_slopbuf[1];
294
295 static void add_object_array_with_mode_context(struct object *obj, const char *name,
296 struct object_array *array,
297 unsigned mode,
298 struct object_context *context)
299 {
300 unsigned nr = array->nr;
301 unsigned alloc = array->alloc;
302 struct object_array_entry *objects = array->objects;
303 struct object_array_entry *entry;
304
305 if (nr >= alloc) {
306 alloc = (alloc + 32) * 2;
307 objects = xrealloc(objects, alloc * sizeof(*objects));
308 array->alloc = alloc;
309 array->objects = objects;
310 }
311 entry = &objects[nr];
312 entry->item = obj;
313 if (!name)
314 entry->name = NULL;
315 else if (!*name)
316 /* Use our own empty string instead of allocating one: */
317 entry->name = object_array_slopbuf;
318 else
319 entry->name = xstrdup(name);
320 entry->mode = mode;
321 entry->context = context;
322 array->nr = ++nr;
323 }
324
325 void add_object_array(struct object *obj, const char *name, struct object_array *array)
326 {
327 add_object_array_with_mode(obj, name, array, S_IFINVALID);
328 }
329
330 void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
331 {
332 add_object_array_with_mode_context(obj, name, array, mode, NULL);
333 }
334
335 void add_object_array_with_context(struct object *obj, const char *name, struct object_array *array, struct object_context *context)
336 {
337 if (context)
338 add_object_array_with_mode_context(obj, name, array, context->mode, context);
339 else
340 add_object_array_with_mode_context(obj, name, array, S_IFINVALID, context);
341 }
342
343 void object_array_filter(struct object_array *array,
344 object_array_each_func_t want, void *cb_data)
345 {
346 unsigned nr = array->nr, src, dst;
347 struct object_array_entry *objects = array->objects;
348
349 for (src = dst = 0; src < nr; src++) {
350 if (want(&objects[src], cb_data)) {
351 if (src != dst)
352 objects[dst] = objects[src];
353 dst++;
354 } else {
355 if (objects[src].name != object_array_slopbuf)
356 free(objects[src].name);
357 }
358 }
359 array->nr = dst;
360 }
361
362 /*
363 * Return true iff array already contains an entry with name.
364 */
365 static int contains_name(struct object_array *array, const char *name)
366 {
367 unsigned nr = array->nr, i;
368 struct object_array_entry *object = array->objects;
369
370 for (i = 0; i < nr; i++, object++)
371 if (!strcmp(object->name, name))
372 return 1;
373 return 0;
374 }
375
376 void object_array_remove_duplicates(struct object_array *array)
377 {
378 unsigned nr = array->nr, src;
379 struct object_array_entry *objects = array->objects;
380
381 array->nr = 0;
382 for (src = 0; src < nr; src++) {
383 if (!contains_name(array, objects[src].name)) {
384 if (src != array->nr)
385 objects[array->nr] = objects[src];
386 array->nr++;
387 } else {
388 if (objects[src].name != object_array_slopbuf)
389 free(objects[src].name);
390 }
391 }
392 }
393
394 void clear_object_flags(unsigned flags)
395 {
396 int i;
397
398 for (i=0; i < obj_hash_size; i++) {
399 struct object *obj = obj_hash[i];
400 if (obj)
401 obj->flags &= ~flags;
402 }
403 }