doc: describe git svn init --ignore-refs
[git/git-svn.git] / object.c
blob06ba3a11d87ad7b93f29aef535e773fcc4683004
1 #include "cache.h"
2 #include "object.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "commit.h"
6 #include "tag.h"
8 static struct object **obj_hash;
9 static int nr_objs, obj_hash_size;
11 unsigned int get_max_object_index(void)
13 return obj_hash_size;
16 struct object *get_indexed_object(unsigned int idx)
18 return obj_hash[idx];
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 */
29 const char *typename(unsigned int type)
31 if (type >= ARRAY_SIZE(object_type_strings))
32 return NULL;
33 return object_type_strings[type];
36 int type_from_string_gently(const char *str, ssize_t len, int gentle)
38 int i;
40 if (len < 0)
41 len = strlen(str);
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;
48 if (gentle)
49 return -1;
51 die("invalid object type \"%s\"", str);
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.
59 static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
61 return sha1hash(sha1) & (n - 1);
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.
69 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
71 unsigned int j = hash_obj(obj->oid.hash, size);
73 while (hash[j]) {
74 j++;
75 if (j >= size)
76 j = 0;
78 hash[j] = obj;
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.
85 struct object *lookup_object(const unsigned char *sha1)
87 unsigned int i, first;
88 struct object *obj;
90 if (!obj_hash)
91 return NULL;
93 first = i = hash_obj(sha1, obj_hash_size);
94 while ((obj = obj_hash[i]) != NULL) {
95 if (!hashcmp(sha1, obj->oid.hash))
96 break;
97 i++;
98 if (i == obj_hash_size)
99 i = 0;
101 if (obj && i != first) {
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.
107 SWAP(obj_hash[i], obj_hash[first]);
109 return obj;
113 * Increase the size of the hash map stored in obj_hash to the next
114 * power of 2 (but at least 32). Copy the existing values to the new
115 * hash map.
117 static void grow_object_hash(void)
119 int i;
121 * Note that this size must always be power-of-2 to match hash_obj
122 * above.
124 int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
125 struct object **new_hash;
127 new_hash = xcalloc(new_hash_size, sizeof(struct object *));
128 for (i = 0; i < obj_hash_size; i++) {
129 struct object *obj = obj_hash[i];
130 if (!obj)
131 continue;
132 insert_obj_hash(obj, new_hash, new_hash_size);
134 free(obj_hash);
135 obj_hash = new_hash;
136 obj_hash_size = new_hash_size;
139 void *create_object(const unsigned char *sha1, void *o)
141 struct object *obj = o;
143 obj->parsed = 0;
144 obj->used = 0;
145 obj->flags = 0;
146 hashcpy(obj->oid.hash, sha1);
148 if (obj_hash_size - 1 <= nr_objs * 2)
149 grow_object_hash();
151 insert_obj_hash(obj, obj_hash, obj_hash_size);
152 nr_objs++;
153 return obj;
156 void *object_as_type(struct object *obj, enum object_type type, int quiet)
158 if (obj->type == type)
159 return obj;
160 else if (obj->type == OBJ_NONE) {
161 if (type == OBJ_COMMIT)
162 ((struct commit *)obj)->index = alloc_commit_index();
163 obj->type = type;
164 return obj;
166 else {
167 if (!quiet)
168 error("object %s is a %s, not a %s",
169 oid_to_hex(&obj->oid),
170 typename(obj->type), typename(type));
171 return NULL;
175 struct object *lookup_unknown_object(const unsigned char *sha1)
177 struct object *obj = lookup_object(sha1);
178 if (!obj)
179 obj = create_object(sha1, alloc_object_node());
180 return obj;
183 struct object *parse_object_buffer(const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
185 struct object *obj;
186 *eaten_p = 0;
188 obj = NULL;
189 if (type == OBJ_BLOB) {
190 struct blob *blob = lookup_blob(oid);
191 if (blob) {
192 if (parse_blob_buffer(blob, buffer, size))
193 return NULL;
194 obj = &blob->object;
196 } else if (type == OBJ_TREE) {
197 struct tree *tree = lookup_tree(oid);
198 if (tree) {
199 obj = &tree->object;
200 if (!tree->buffer)
201 tree->object.parsed = 0;
202 if (!tree->object.parsed) {
203 if (parse_tree_buffer(tree, buffer, size))
204 return NULL;
205 *eaten_p = 1;
208 } else if (type == OBJ_COMMIT) {
209 struct commit *commit = lookup_commit(oid);
210 if (commit) {
211 if (parse_commit_buffer(commit, buffer, size))
212 return NULL;
213 if (!get_cached_commit_buffer(commit, NULL)) {
214 set_commit_buffer(commit, buffer, size);
215 *eaten_p = 1;
217 obj = &commit->object;
219 } else if (type == OBJ_TAG) {
220 struct tag *tag = lookup_tag(oid);
221 if (tag) {
222 if (parse_tag_buffer(tag, buffer, size))
223 return NULL;
224 obj = &tag->object;
226 } else {
227 warning("object %s has unknown type id %d", oid_to_hex(oid), type);
228 obj = NULL;
230 return obj;
233 struct object *parse_object_or_die(const struct object_id *oid,
234 const char *name)
236 struct object *o = parse_object(oid);
237 if (o)
238 return o;
240 die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
243 struct object *parse_object(const struct object_id *oid)
245 unsigned long size;
246 enum object_type type;
247 int eaten;
248 const unsigned char *repl = lookup_replace_object(oid->hash);
249 void *buffer;
250 struct object *obj;
252 obj = lookup_object(oid->hash);
253 if (obj && obj->parsed)
254 return obj;
256 if ((obj && obj->type == OBJ_BLOB) ||
257 (!obj && has_object_file(oid) &&
258 sha1_object_info(oid->hash, NULL) == OBJ_BLOB)) {
259 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
260 error("sha1 mismatch %s", oid_to_hex(oid));
261 return NULL;
263 parse_blob_buffer(lookup_blob(oid), NULL, 0);
264 return lookup_object(oid->hash);
267 buffer = read_sha1_file(oid->hash, &type, &size);
268 if (buffer) {
269 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
270 free(buffer);
271 error("sha1 mismatch %s", sha1_to_hex(repl));
272 return NULL;
275 obj = parse_object_buffer(oid, type, size, buffer, &eaten);
276 if (!eaten)
277 free(buffer);
278 return obj;
280 return NULL;
283 struct object_list *object_list_insert(struct object *item,
284 struct object_list **list_p)
286 struct object_list *new_list = xmalloc(sizeof(struct object_list));
287 new_list->item = item;
288 new_list->next = *list_p;
289 *list_p = new_list;
290 return new_list;
293 int object_list_contains(struct object_list *list, struct object *obj)
295 while (list) {
296 if (list->item == obj)
297 return 1;
298 list = list->next;
300 return 0;
304 * A zero-length string to which object_array_entry::name can be
305 * initialized without requiring a malloc/free.
307 static char object_array_slopbuf[1];
309 void add_object_array_with_path(struct object *obj, const char *name,
310 struct object_array *array,
311 unsigned mode, const char *path)
313 unsigned nr = array->nr;
314 unsigned alloc = array->alloc;
315 struct object_array_entry *objects = array->objects;
316 struct object_array_entry *entry;
318 if (nr >= alloc) {
319 alloc = (alloc + 32) * 2;
320 REALLOC_ARRAY(objects, alloc);
321 array->alloc = alloc;
322 array->objects = objects;
324 entry = &objects[nr];
325 entry->item = obj;
326 if (!name)
327 entry->name = NULL;
328 else if (!*name)
329 /* Use our own empty string instead of allocating one: */
330 entry->name = object_array_slopbuf;
331 else
332 entry->name = xstrdup(name);
333 entry->mode = mode;
334 if (path)
335 entry->path = xstrdup(path);
336 else
337 entry->path = NULL;
338 array->nr = ++nr;
341 void add_object_array(struct object *obj, const char *name, struct object_array *array)
343 add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
347 * Free all memory associated with an entry; the result is
348 * in an unspecified state and should not be examined.
350 static void object_array_release_entry(struct object_array_entry *ent)
352 if (ent->name != object_array_slopbuf)
353 free(ent->name);
354 free(ent->path);
357 void object_array_filter(struct object_array *array,
358 object_array_each_func_t want, void *cb_data)
360 unsigned nr = array->nr, src, dst;
361 struct object_array_entry *objects = array->objects;
363 for (src = dst = 0; src < nr; src++) {
364 if (want(&objects[src], cb_data)) {
365 if (src != dst)
366 objects[dst] = objects[src];
367 dst++;
368 } else {
369 object_array_release_entry(&objects[src]);
372 array->nr = dst;
375 void object_array_clear(struct object_array *array)
377 int i;
378 for (i = 0; i < array->nr; i++)
379 object_array_release_entry(&array->objects[i]);
380 free(array->objects);
381 array->objects = NULL;
382 array->nr = array->alloc = 0;
386 * Return true iff array already contains an entry with name.
388 static int contains_name(struct object_array *array, const char *name)
390 unsigned nr = array->nr, i;
391 struct object_array_entry *object = array->objects;
393 for (i = 0; i < nr; i++, object++)
394 if (!strcmp(object->name, name))
395 return 1;
396 return 0;
399 void object_array_remove_duplicates(struct object_array *array)
401 unsigned nr = array->nr, src;
402 struct object_array_entry *objects = array->objects;
404 array->nr = 0;
405 for (src = 0; src < nr; src++) {
406 if (!contains_name(array, objects[src].name)) {
407 if (src != array->nr)
408 objects[array->nr] = objects[src];
409 array->nr++;
410 } else {
411 object_array_release_entry(&objects[src]);
416 void clear_object_flags(unsigned flags)
418 int i;
420 for (i=0; i < obj_hash_size; i++) {
421 struct object *obj = obj_hash[i];
422 if (obj)
423 obj->flags &= ~flags;