repository.h: add comment and clarify repo_set_gitdir
[git/git.git] / object.c
CommitLineData
8f1d2e6f 1#include "cache.h"
175785e5 2#include "object.h"
e9eefa67
DB
3#include "blob.h"
4#include "tree.h"
5#include "commit.h"
e9eefa67 6#include "tag.h"
175785e5 7
0556a11a
LT
8static struct object **obj_hash;
9static int nr_objs, obj_hash_size;
fc046a75
LT
10
11unsigned int get_max_object_index(void)
12{
0556a11a 13 return obj_hash_size;
fc046a75
LT
14}
15
16struct object *get_indexed_object(unsigned int idx)
17{
0556a11a 18 return obj_hash[idx];
fc046a75 19}
175785e5 20
df843662
NP
21static 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 */
885a86ab
LT
27};
28
df843662
NP
29const 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
fe8e3b71 36int type_from_string_gently(const char *str, ssize_t len, int gentle)
df843662
NP
37{
38 int i;
39
fe8e3b71
JS
40 if (len < 0)
41 len = strlen(str);
42
df843662 43 for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
b7994af0
JK
44 if (!strncmp(str, object_type_strings[i], len) &&
45 object_type_strings[i][len] == '\0')
df843662 46 return i;
fe8e3b71
JS
47
48 if (gentle)
49 return -1;
50
df843662
NP
51 die("invalid object type \"%s\"", str);
52}
53
33bef7ea
MH
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 */
9f36c9b7 59static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
0556a11a 60{
039dc71a 61 return sha1hash(sha1) & (n - 1);
0556a11a
LT
62}
63
33bef7ea
MH
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 */
0556a11a
LT
69static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
70{
ed1c9977 71 unsigned int j = hash_obj(obj->oid.hash, size);
0556a11a
LT
72
73 while (hash[j]) {
74 j++;
75 if (j >= size)
76 j = 0;
77 }
78 hash[j] = obj;
79}
80
33bef7ea
MH
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 */
0556a11a 85struct object *lookup_object(const unsigned char *sha1)
175785e5 86{
9a414486 87 unsigned int i, first;
0556a11a 88 struct object *obj;
175785e5 89
0556a11a
LT
90 if (!obj_hash)
91 return NULL;
175785e5 92
9f36c9b7 93 first = i = hash_obj(sha1, obj_hash_size);
0556a11a 94 while ((obj = obj_hash[i]) != NULL) {
ed1c9977 95 if (!hashcmp(sha1, obj->oid.hash))
0556a11a 96 break;
070879ca 97 i++;
0556a11a 98 if (i == obj_hash_size)
070879ca
JS
99 i = 0;
100 }
9a414486
JK
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 */
35d803bc 107 SWAP(obj_hash[i], obj_hash[first]);
9a414486 108 }
0556a11a 109 return obj;
175785e5
DB
110}
111
33bef7ea
MH
112/*
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.
116 */
0556a11a 117static void grow_object_hash(void)
175785e5 118{
0556a11a 119 int i;
9f36c9b7
NP
120 /*
121 * Note that this size must always be power-of-2 to match hash_obj
122 * above.
123 */
0556a11a
LT
124 int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
125 struct object **new_hash;
126
b3c952f8 127 new_hash = xcalloc(new_hash_size, sizeof(struct object *));
0556a11a
LT
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);
133 }
134 free(obj_hash);
135 obj_hash = new_hash;
136 obj_hash_size = new_hash_size;
175785e5
DB
137}
138
d36f51c1 139void *create_object(const unsigned char *sha1, void *o)
175785e5 140{
100c5f3b
LT
141 struct object *obj = o;
142
175785e5 143 obj->parsed = 0;
0556a11a 144 obj->flags = 0;
ed1c9977 145 hashcpy(obj->oid.hash, sha1);
175785e5 146
0556a11a
LT
147 if (obj_hash_size - 1 <= nr_objs * 2)
148 grow_object_hash();
175785e5 149
0556a11a 150 insert_obj_hash(obj, obj_hash, obj_hash_size);
175785e5 151 nr_objs++;
100c5f3b 152 return obj;
175785e5
DB
153}
154
8ff226a9
JK
155void *object_as_type(struct object *obj, enum object_type type, int quiet)
156{
157 if (obj->type == type)
158 return obj;
159 else if (obj->type == OBJ_NONE) {
d66bebcb
JK
160 if (type == OBJ_COMMIT)
161 ((struct commit *)obj)->index = alloc_commit_index();
8ff226a9
JK
162 obj->type = type;
163 return obj;
164 }
165 else {
166 if (!quiet)
167 error("object %s is a %s, not a %s",
f2fd0760 168 oid_to_hex(&obj->oid),
8ff226a9
JK
169 typename(obj->type), typename(type));
170 return NULL;
171 }
172}
173
66e481b0
DB
174struct object *lookup_unknown_object(const unsigned char *sha1)
175{
176 struct object *obj = lookup_object(sha1);
100c5f3b 177 if (!obj)
d36f51c1 178 obj = create_object(sha1, alloc_object_node());
66e481b0
DB
179 return obj;
180}
181
c251c83d 182struct object *parse_object_buffer(const struct object_id *oid, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
9f613ddd
JH
183{
184 struct object *obj;
8e92e8f2 185 *eaten_p = 0;
9f613ddd 186
cc216827 187 obj = NULL;
21666f1a 188 if (type == OBJ_BLOB) {
c251c83d 189 struct blob *blob = lookup_blob(oid);
cc216827 190 if (blob) {
d0b8c9e5
MK
191 if (parse_blob_buffer(blob, buffer, size))
192 return NULL;
cc216827
JM
193 obj = &blob->object;
194 }
21666f1a 195 } else if (type == OBJ_TREE) {
c251c83d 196 struct tree *tree = lookup_tree(oid);
cc216827
JM
197 if (tree) {
198 obj = &tree->object;
68be2fea
JH
199 if (!tree->buffer)
200 tree->object.parsed = 0;
cc216827 201 if (!tree->object.parsed) {
d0b8c9e5
MK
202 if (parse_tree_buffer(tree, buffer, size))
203 return NULL;
8e92e8f2 204 *eaten_p = 1;
cc216827 205 }
9f613ddd 206 }
21666f1a 207 } else if (type == OBJ_COMMIT) {
c251c83d 208 struct commit *commit = lookup_commit(oid);
cc216827 209 if (commit) {
d0b8c9e5
MK
210 if (parse_commit_buffer(commit, buffer, size))
211 return NULL;
8597ea3a
JK
212 if (!get_cached_commit_buffer(commit, NULL)) {
213 set_commit_buffer(commit, buffer, size);
8e92e8f2 214 *eaten_p = 1;
cc216827
JM
215 }
216 obj = &commit->object;
9f613ddd 217 }
21666f1a 218 } else if (type == OBJ_TAG) {
c251c83d 219 struct tag *tag = lookup_tag(oid);
cc216827 220 if (tag) {
d0b8c9e5
MK
221 if (parse_tag_buffer(tag, buffer, size))
222 return NULL;
cc216827
JM
223 obj = &tag->object;
224 }
9f613ddd 225 } else {
c251c83d 226 warning("object %s has unknown type id %d", oid_to_hex(oid), type);
9f613ddd
JH
227 obj = NULL;
228 }
9f613ddd
JH
229 return obj;
230}
231
c251c83d 232struct object *parse_object_or_die(const struct object_id *oid,
75a95490
JK
233 const char *name)
234{
c251c83d 235 struct object *o = parse_object(oid);
75a95490
JK
236 if (o)
237 return o;
238
c251c83d 239 die(_("unable to parse object: %s"), name ? name : oid_to_hex(oid));
75a95490
JK
240}
241
c251c83d 242struct object *parse_object(const struct object_id *oid)
e9eefa67 243{
c4584ae3 244 unsigned long size;
21666f1a 245 enum object_type type;
9f613ddd 246 int eaten;
c251c83d 247 const unsigned char *repl = lookup_replace_object(oid->hash);
ccdc6037
JK
248 void *buffer;
249 struct object *obj;
250
c251c83d 251 obj = lookup_object(oid->hash);
ccdc6037
JK
252 if (obj && obj->parsed)
253 return obj;
9f613ddd 254
df11e196 255 if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
c251c83d 256 (!obj && has_object_file(oid) &&
257 sha1_object_info(oid->hash, NULL) == OBJ_BLOB)) {
090ea126 258 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
c251c83d 259 error("sha1 mismatch %s", oid_to_hex(oid));
090ea126
NTND
260 return NULL;
261 }
c251c83d 262 parse_blob_buffer(lookup_blob(oid), NULL, 0);
263 return lookup_object(oid->hash);
090ea126
NTND
264 }
265
c251c83d 266 buffer = read_sha1_file(oid->hash, &type, &size);
c4584ae3 267 if (buffer) {
0e87c367 268 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
0b1f1130 269 free(buffer);
82247e9b 270 error("sha1 mismatch %s", sha1_to_hex(repl));
acdeec62
LT
271 return NULL;
272 }
9f613ddd 273
c251c83d 274 obj = parse_object_buffer(oid, type, size, buffer, &eaten);
9f613ddd
JH
275 if (!eaten)
276 free(buffer);
bd2c39f5 277 return obj;
e9eefa67
DB
278 }
279 return NULL;
280}
66e481b0
DB
281
282struct object_list *object_list_insert(struct object *item,
283 struct object_list **list_p)
284{
285 struct object_list *new_list = xmalloc(sizeof(struct object_list));
55b4e9e4
JH
286 new_list->item = item;
287 new_list->next = *list_p;
288 *list_p = new_list;
289 return new_list;
66e481b0
DB
290}
291
66e481b0
DB
292int object_list_contains(struct object_list *list, struct object *obj)
293{
294 while (list) {
295 if (list->item == obj)
296 return 1;
297 list = list->next;
298 }
299 return 0;
300}
1f1e895f 301
31faeb20
MH
302/*
303 * A zero-length string to which object_array_entry::name can be
304 * initialized without requiring a malloc/free.
305 */
306static char object_array_slopbuf[1];
307
9e0c3c4f
JK
308void add_object_array_with_path(struct object *obj, const char *name,
309 struct object_array *array,
310 unsigned mode, const char *path)
1f1e895f
LT
311{
312 unsigned nr = array->nr;
313 unsigned alloc = array->alloc;
314 struct object_array_entry *objects = array->objects;
31faeb20 315 struct object_array_entry *entry;
1f1e895f
LT
316
317 if (nr >= alloc) {
318 alloc = (alloc + 32) * 2;
2756ca43 319 REALLOC_ARRAY(objects, alloc);
1f1e895f
LT
320 array->alloc = alloc;
321 array->objects = objects;
322 }
31faeb20
MH
323 entry = &objects[nr];
324 entry->item = obj;
325 if (!name)
326 entry->name = NULL;
327 else if (!*name)
328 /* Use our own empty string instead of allocating one: */
329 entry->name = object_array_slopbuf;
330 else
331 entry->name = xstrdup(name);
332 entry->mode = mode;
9e0c3c4f
JK
333 if (path)
334 entry->path = xstrdup(path);
335 else
336 entry->path = NULL;
1f1e895f
LT
337 array->nr = ++nr;
338}
b2a6d1c6 339
afa15f3c
MG
340void add_object_array(struct object *obj, const char *name, struct object_array *array)
341{
189a1222 342 add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
afa15f3c
MG
343}
344
68f49235
JK
345/*
346 * Free all memory associated with an entry; the result is
347 * in an unspecified state and should not be examined.
348 */
349static void object_array_release_entry(struct object_array_entry *ent)
350{
351 if (ent->name != object_array_slopbuf)
352 free(ent->name);
9e0c3c4f 353 free(ent->path);
68f49235
JK
354}
355
71992039
356struct object *object_array_pop(struct object_array *array)
357{
358 struct object *ret;
359
360 if (!array->nr)
361 return NULL;
362
363 ret = array->objects[array->nr - 1].item;
364 object_array_release_entry(&array->objects[array->nr - 1]);
365 array->nr--;
366 return ret;
367}
368
aeb4a51e
MH
369void object_array_filter(struct object_array *array,
370 object_array_each_func_t want, void *cb_data)
b2a6d1c6 371{
aeb4a51e 372 unsigned nr = array->nr, src, dst;
b2a6d1c6
JH
373 struct object_array_entry *objects = array->objects;
374
aeb4a51e
MH
375 for (src = dst = 0; src < nr; src++) {
376 if (want(&objects[src], cb_data)) {
b2a6d1c6
JH
377 if (src != dst)
378 objects[dst] = objects[src];
379 dst++;
31faeb20 380 } else {
68f49235 381 object_array_release_entry(&objects[src]);
aeb4a51e
MH
382 }
383 }
384 array->nr = dst;
385}
386
46be8231
JK
387void object_array_clear(struct object_array *array)
388{
389 int i;
390 for (i = 0; i < array->nr; i++)
391 object_array_release_entry(&array->objects[i]);
6a83d902 392 FREE_AND_NULL(array->objects);
46be8231
JK
393 array->nr = array->alloc = 0;
394}
395
1506510c
MH
396/*
397 * Return true iff array already contains an entry with name.
398 */
399static int contains_name(struct object_array *array, const char *name)
400{
401 unsigned nr = array->nr, i;
402 struct object_array_entry *object = array->objects;
403
404 for (i = 0; i < nr; i++, object++)
405 if (!strcmp(object->name, name))
406 return 1;
407 return 0;
408}
409
b2a6d1c6
JH
410void object_array_remove_duplicates(struct object_array *array)
411{
1506510c 412 unsigned nr = array->nr, src;
b2a6d1c6
JH
413 struct object_array_entry *objects = array->objects;
414
1506510c
MH
415 array->nr = 0;
416 for (src = 0; src < nr; src++) {
417 if (!contains_name(array, objects[src].name)) {
418 if (src != array->nr)
419 objects[array->nr] = objects[src];
420 array->nr++;
31faeb20 421 } else {
68f49235 422 object_array_release_entry(&objects[src]);
b2a6d1c6 423 }
b2a6d1c6
JH
424 }
425}
bcc0a3ea
HV
426
427void clear_object_flags(unsigned flags)
428{
429 int i;
430
431 for (i=0; i < obj_hash_size; i++) {
432 struct object *obj = obj_hash[i];
433 if (obj)
434 obj->flags &= ~flags;
435 }
436}
4ad315fc
RS
437
438void clear_commit_marks_all(unsigned int flags)
439{
440 int i;
441
442 for (i = 0; i < obj_hash_size; i++) {
443 struct object *obj = obj_hash[i];
444 if (obj && obj->type == OBJ_COMMIT)
445 obj->flags &= ~flags;
446 }
447}