Convert struct object to object_id
[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_gently(const char *str, ssize_t len, int gentle)
37 {
38 int i;
39
40 if (len < 0)
41 len = strlen(str);
42
43 for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
44 if (!strncmp(str, object_type_strings[i], len) &&
45 object_type_strings[i][len] == '\0')
46 return i;
47
48 if (gentle)
49 return -1;
50
51 die("invalid object type \"%s\"", str);
52 }
53
54 /*
55 * Return a numerical hash value between 0 and n-1 for the object with
56 * the specified sha1. n must be a power of 2. Please note that the
57 * return value is *not* consistent across computer architectures.
58 */
59 static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
60 {
61 return sha1hash(sha1) & (n - 1);
62 }
63
64 /*
65 * Insert obj into the hash table hash, which has length size (which
66 * must be a power of 2). On collisions, simply overflow to the next
67 * empty bucket.
68 */
69 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
70 {
71 unsigned int j = hash_obj(get_object_hash(*obj), size);
72
73 while (hash[j]) {
74 j++;
75 if (j >= size)
76 j = 0;
77 }
78 hash[j] = obj;
79 }
80
81 /*
82 * Look up the record for the given sha1 in the hash map stored in
83 * obj_hash. Return NULL if it was not found.
84 */
85 struct object *lookup_object(const unsigned char *sha1)
86 {
87 unsigned int i, first;
88 struct object *obj;
89
90 if (!obj_hash)
91 return NULL;
92
93 first = i = hash_obj(sha1, obj_hash_size);
94 while ((obj = obj_hash[i]) != NULL) {
95 if (!hashcmp(sha1, get_object_hash(*obj)))
96 break;
97 i++;
98 if (i == obj_hash_size)
99 i = 0;
100 }
101 if (obj && i != first) {
102 /*
103 * Move object to where we started to look for it so
104 * that we do not need to walk the hash table the next
105 * time we look for it.
106 */
107 struct object *tmp = obj_hash[i];
108 obj_hash[i] = obj_hash[first];
109 obj_hash[first] = tmp;
110 }
111 return obj;
112 }
113
114 /*
115 * Increase the size of the hash map stored in obj_hash to the next
116 * power of 2 (but at least 32). Copy the existing values to the new
117 * hash map.
118 */
119 static void grow_object_hash(void)
120 {
121 int i;
122 /*
123 * Note that this size must always be power-of-2 to match hash_obj
124 * above.
125 */
126 int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
127 struct object **new_hash;
128
129 new_hash = xcalloc(new_hash_size, sizeof(struct object *));
130 for (i = 0; i < obj_hash_size; i++) {
131 struct object *obj = obj_hash[i];
132 if (!obj)
133 continue;
134 insert_obj_hash(obj, new_hash, new_hash_size);
135 }
136 free(obj_hash);
137 obj_hash = new_hash;
138 obj_hash_size = new_hash_size;
139 }
140
141 void *create_object(const unsigned char *sha1, void *o)
142 {
143 struct object *obj = o;
144
145 obj->parsed = 0;
146 obj->used = 0;
147 obj->flags = 0;
148 hashcpy(get_object_hash(*obj), sha1);
149
150 if (obj_hash_size - 1 <= nr_objs * 2)
151 grow_object_hash();
152
153 insert_obj_hash(obj, obj_hash, obj_hash_size);
154 nr_objs++;
155 return obj;
156 }
157
158 void *object_as_type(struct object *obj, enum object_type type, int quiet)
159 {
160 if (obj->type == type)
161 return obj;
162 else if (obj->type == OBJ_NONE) {
163 if (type == OBJ_COMMIT)
164 ((struct commit *)obj)->index = alloc_commit_index();
165 obj->type = type;
166 return obj;
167 }
168 else {
169 if (!quiet)
170 error("object %s is a %s, not a %s",
171 oid_to_hex(&obj->oid),
172 typename(obj->type), typename(type));
173 return NULL;
174 }
175 }
176
177 struct object *lookup_unknown_object(const unsigned char *sha1)
178 {
179 struct object *obj = lookup_object(sha1);
180 if (!obj)
181 obj = create_object(sha1, alloc_object_node());
182 return obj;
183 }
184
185 struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
186 {
187 struct object *obj;
188 *eaten_p = 0;
189
190 obj = NULL;
191 if (type == OBJ_BLOB) {
192 struct blob *blob = lookup_blob(sha1);
193 if (blob) {
194 if (parse_blob_buffer(blob, buffer, size))
195 return NULL;
196 obj = &blob->object;
197 }
198 } else if (type == OBJ_TREE) {
199 struct tree *tree = lookup_tree(sha1);
200 if (tree) {
201 obj = &tree->object;
202 if (!tree->buffer)
203 tree->object.parsed = 0;
204 if (!tree->object.parsed) {
205 if (parse_tree_buffer(tree, buffer, size))
206 return NULL;
207 *eaten_p = 1;
208 }
209 }
210 } else if (type == OBJ_COMMIT) {
211 struct commit *commit = lookup_commit(sha1);
212 if (commit) {
213 if (parse_commit_buffer(commit, buffer, size))
214 return NULL;
215 if (!get_cached_commit_buffer(commit, NULL)) {
216 set_commit_buffer(commit, buffer, size);
217 *eaten_p = 1;
218 }
219 obj = &commit->object;
220 }
221 } else if (type == OBJ_TAG) {
222 struct tag *tag = lookup_tag(sha1);
223 if (tag) {
224 if (parse_tag_buffer(tag, buffer, size))
225 return NULL;
226 obj = &tag->object;
227 }
228 } else {
229 warning("object %s has unknown type id %d", sha1_to_hex(sha1), type);
230 obj = NULL;
231 }
232 return obj;
233 }
234
235 struct object *parse_object_or_die(const unsigned char *sha1,
236 const char *name)
237 {
238 struct object *o = parse_object(sha1);
239 if (o)
240 return o;
241
242 die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1));
243 }
244
245 struct object *parse_object(const unsigned char *sha1)
246 {
247 unsigned long size;
248 enum object_type type;
249 int eaten;
250 const unsigned char *repl = lookup_replace_object(sha1);
251 void *buffer;
252 struct object *obj;
253
254 obj = lookup_object(sha1);
255 if (obj && obj->parsed)
256 return obj;
257
258 if ((obj && obj->type == OBJ_BLOB) ||
259 (!obj && has_sha1_file(sha1) &&
260 sha1_object_info(sha1, NULL) == OBJ_BLOB)) {
261 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
262 error("sha1 mismatch %s", sha1_to_hex(repl));
263 return NULL;
264 }
265 parse_blob_buffer(lookup_blob(sha1), NULL, 0);
266 return lookup_object(sha1);
267 }
268
269 buffer = read_sha1_file(sha1, &type, &size);
270 if (buffer) {
271 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
272 free(buffer);
273 error("sha1 mismatch %s", sha1_to_hex(repl));
274 return NULL;
275 }
276
277 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
278 if (!eaten)
279 free(buffer);
280 return obj;
281 }
282 return NULL;
283 }
284
285 struct object_list *object_list_insert(struct object *item,
286 struct object_list **list_p)
287 {
288 struct object_list *new_list = xmalloc(sizeof(struct object_list));
289 new_list->item = item;
290 new_list->next = *list_p;
291 *list_p = new_list;
292 return new_list;
293 }
294
295 int object_list_contains(struct object_list *list, struct object *obj)
296 {
297 while (list) {
298 if (list->item == obj)
299 return 1;
300 list = list->next;
301 }
302 return 0;
303 }
304
305 /*
306 * A zero-length string to which object_array_entry::name can be
307 * initialized without requiring a malloc/free.
308 */
309 static char object_array_slopbuf[1];
310
311 void add_object_array_with_path(struct object *obj, const char *name,
312 struct object_array *array,
313 unsigned mode, const char *path)
314 {
315 unsigned nr = array->nr;
316 unsigned alloc = array->alloc;
317 struct object_array_entry *objects = array->objects;
318 struct object_array_entry *entry;
319
320 if (nr >= alloc) {
321 alloc = (alloc + 32) * 2;
322 REALLOC_ARRAY(objects, alloc);
323 array->alloc = alloc;
324 array->objects = objects;
325 }
326 entry = &objects[nr];
327 entry->item = obj;
328 if (!name)
329 entry->name = NULL;
330 else if (!*name)
331 /* Use our own empty string instead of allocating one: */
332 entry->name = object_array_slopbuf;
333 else
334 entry->name = xstrdup(name);
335 entry->mode = mode;
336 if (path)
337 entry->path = xstrdup(path);
338 else
339 entry->path = NULL;
340 array->nr = ++nr;
341 }
342
343 void add_object_array(struct object *obj, const char *name, struct object_array *array)
344 {
345 add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
346 }
347
348 /*
349 * Free all memory associated with an entry; the result is
350 * in an unspecified state and should not be examined.
351 */
352 static void object_array_release_entry(struct object_array_entry *ent)
353 {
354 if (ent->name != object_array_slopbuf)
355 free(ent->name);
356 free(ent->path);
357 }
358
359 void object_array_filter(struct object_array *array,
360 object_array_each_func_t want, void *cb_data)
361 {
362 unsigned nr = array->nr, src, dst;
363 struct object_array_entry *objects = array->objects;
364
365 for (src = dst = 0; src < nr; src++) {
366 if (want(&objects[src], cb_data)) {
367 if (src != dst)
368 objects[dst] = objects[src];
369 dst++;
370 } else {
371 object_array_release_entry(&objects[src]);
372 }
373 }
374 array->nr = dst;
375 }
376
377 void object_array_clear(struct object_array *array)
378 {
379 int i;
380 for (i = 0; i < array->nr; i++)
381 object_array_release_entry(&array->objects[i]);
382 free(array->objects);
383 array->objects = NULL;
384 array->nr = array->alloc = 0;
385 }
386
387 /*
388 * Return true iff array already contains an entry with name.
389 */
390 static int contains_name(struct object_array *array, const char *name)
391 {
392 unsigned nr = array->nr, i;
393 struct object_array_entry *object = array->objects;
394
395 for (i = 0; i < nr; i++, object++)
396 if (!strcmp(object->name, name))
397 return 1;
398 return 0;
399 }
400
401 void object_array_remove_duplicates(struct object_array *array)
402 {
403 unsigned nr = array->nr, src;
404 struct object_array_entry *objects = array->objects;
405
406 array->nr = 0;
407 for (src = 0; src < nr; src++) {
408 if (!contains_name(array, objects[src].name)) {
409 if (src != array->nr)
410 objects[array->nr] = objects[src];
411 array->nr++;
412 } else {
413 object_array_release_entry(&objects[src]);
414 }
415 }
416 }
417
418 void clear_object_flags(unsigned flags)
419 {
420 int i;
421
422 for (i=0; i < obj_hash_size; i++) {
423 struct object *obj = obj_hash[i];
424 if (obj)
425 obj->flags &= ~flags;
426 }
427 }