use SWAP macro
[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;
175785e5 144 obj->used = 0;
0556a11a 145 obj->flags = 0;
ed1c9977 146 hashcpy(obj->oid.hash, sha1);
175785e5 147
0556a11a
LT
148 if (obj_hash_size - 1 <= nr_objs * 2)
149 grow_object_hash();
175785e5 150
0556a11a 151 insert_obj_hash(obj, obj_hash, obj_hash_size);
175785e5 152 nr_objs++;
100c5f3b 153 return obj;
175785e5
DB
154}
155
8ff226a9
JK
156void *object_as_type(struct object *obj, enum object_type type, int quiet)
157{
158 if (obj->type == type)
159 return obj;
160 else if (obj->type == OBJ_NONE) {
d66bebcb
JK
161 if (type == OBJ_COMMIT)
162 ((struct commit *)obj)->index = alloc_commit_index();
8ff226a9
JK
163 obj->type = type;
164 return obj;
165 }
166 else {
167 if (!quiet)
168 error("object %s is a %s, not a %s",
f2fd0760 169 oid_to_hex(&obj->oid),
8ff226a9
JK
170 typename(obj->type), typename(type));
171 return NULL;
172 }
173}
174
66e481b0
DB
175struct object *lookup_unknown_object(const unsigned char *sha1)
176{
177 struct object *obj = lookup_object(sha1);
100c5f3b 178 if (!obj)
d36f51c1 179 obj = create_object(sha1, alloc_object_node());
66e481b0
DB
180 return obj;
181}
182
21666f1a 183struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
9f613ddd
JH
184{
185 struct object *obj;
8e92e8f2 186 *eaten_p = 0;
9f613ddd 187
cc216827 188 obj = NULL;
21666f1a 189 if (type == OBJ_BLOB) {
9f613ddd 190 struct blob *blob = lookup_blob(sha1);
cc216827 191 if (blob) {
d0b8c9e5
MK
192 if (parse_blob_buffer(blob, buffer, size))
193 return NULL;
cc216827
JM
194 obj = &blob->object;
195 }
21666f1a 196 } else if (type == OBJ_TREE) {
9f613ddd 197 struct tree *tree = lookup_tree(sha1);
cc216827
JM
198 if (tree) {
199 obj = &tree->object;
68be2fea
JH
200 if (!tree->buffer)
201 tree->object.parsed = 0;
cc216827 202 if (!tree->object.parsed) {
d0b8c9e5
MK
203 if (parse_tree_buffer(tree, buffer, size))
204 return NULL;
8e92e8f2 205 *eaten_p = 1;
cc216827 206 }
9f613ddd 207 }
21666f1a 208 } else if (type == OBJ_COMMIT) {
9f613ddd 209 struct commit *commit = lookup_commit(sha1);
cc216827 210 if (commit) {
d0b8c9e5
MK
211 if (parse_commit_buffer(commit, buffer, size))
212 return NULL;
8597ea3a
JK
213 if (!get_cached_commit_buffer(commit, NULL)) {
214 set_commit_buffer(commit, buffer, size);
8e92e8f2 215 *eaten_p = 1;
cc216827
JM
216 }
217 obj = &commit->object;
9f613ddd 218 }
21666f1a 219 } else if (type == OBJ_TAG) {
9f613ddd 220 struct tag *tag = lookup_tag(sha1);
cc216827 221 if (tag) {
d0b8c9e5
MK
222 if (parse_tag_buffer(tag, buffer, size))
223 return NULL;
cc216827
JM
224 obj = &tag->object;
225 }
9f613ddd 226 } else {
82247e9b 227 warning("object %s has unknown type id %d", sha1_to_hex(sha1), type);
9f613ddd
JH
228 obj = NULL;
229 }
9f613ddd
JH
230 return obj;
231}
232
75a95490
JK
233struct object *parse_object_or_die(const unsigned char *sha1,
234 const char *name)
235{
236 struct object *o = parse_object(sha1);
237 if (o)
238 return o;
239
240 die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1));
241}
242
5d6ccf5c 243struct object *parse_object(const unsigned char *sha1)
e9eefa67 244{
c4584ae3 245 unsigned long size;
21666f1a 246 enum object_type type;
9f613ddd 247 int eaten;
4bbf5a26 248 const unsigned char *repl = lookup_replace_object(sha1);
ccdc6037
JK
249 void *buffer;
250 struct object *obj;
251
252 obj = lookup_object(sha1);
253 if (obj && obj->parsed)
254 return obj;
9f613ddd 255
090ea126
NTND
256 if ((obj && obj->type == OBJ_BLOB) ||
257 (!obj && has_sha1_file(sha1) &&
258 sha1_object_info(sha1, NULL) == OBJ_BLOB)) {
259 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
82247e9b 260 error("sha1 mismatch %s", sha1_to_hex(repl));
090ea126
NTND
261 return NULL;
262 }
263 parse_blob_buffer(lookup_blob(sha1), NULL, 0);
264 return lookup_object(sha1);
265 }
266
ccdc6037 267 buffer = read_sha1_file(sha1, &type, &size);
c4584ae3 268 if (buffer) {
0e87c367 269 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
0b1f1130 270 free(buffer);
82247e9b 271 error("sha1 mismatch %s", sha1_to_hex(repl));
acdeec62
LT
272 return NULL;
273 }
9f613ddd 274
2e3400c0 275 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
9f613ddd
JH
276 if (!eaten)
277 free(buffer);
bd2c39f5 278 return obj;
e9eefa67
DB
279 }
280 return NULL;
281}
66e481b0
DB
282
283struct object_list *object_list_insert(struct object *item,
284 struct object_list **list_p)
285{
286 struct object_list *new_list = xmalloc(sizeof(struct object_list));
55b4e9e4
JH
287 new_list->item = item;
288 new_list->next = *list_p;
289 *list_p = new_list;
290 return new_list;
66e481b0
DB
291}
292
66e481b0
DB
293int object_list_contains(struct object_list *list, struct object *obj)
294{
295 while (list) {
296 if (list->item == obj)
297 return 1;
298 list = list->next;
299 }
300 return 0;
301}
1f1e895f 302
31faeb20
MH
303/*
304 * A zero-length string to which object_array_entry::name can be
305 * initialized without requiring a malloc/free.
306 */
307static char object_array_slopbuf[1];
308
9e0c3c4f
JK
309void add_object_array_with_path(struct object *obj, const char *name,
310 struct object_array *array,
311 unsigned mode, const char *path)
1f1e895f
LT
312{
313 unsigned nr = array->nr;
314 unsigned alloc = array->alloc;
315 struct object_array_entry *objects = array->objects;
31faeb20 316 struct object_array_entry *entry;
1f1e895f
LT
317
318 if (nr >= alloc) {
319 alloc = (alloc + 32) * 2;
2756ca43 320 REALLOC_ARRAY(objects, alloc);
1f1e895f
LT
321 array->alloc = alloc;
322 array->objects = objects;
323 }
31faeb20
MH
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;
9e0c3c4f
JK
334 if (path)
335 entry->path = xstrdup(path);
336 else
337 entry->path = NULL;
1f1e895f
LT
338 array->nr = ++nr;
339}
b2a6d1c6 340
afa15f3c
MG
341void add_object_array(struct object *obj, const char *name, struct object_array *array)
342{
189a1222 343 add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
afa15f3c
MG
344}
345
68f49235
JK
346/*
347 * Free all memory associated with an entry; the result is
348 * in an unspecified state and should not be examined.
349 */
350static void object_array_release_entry(struct object_array_entry *ent)
351{
352 if (ent->name != object_array_slopbuf)
353 free(ent->name);
9e0c3c4f 354 free(ent->path);
68f49235
JK
355}
356
aeb4a51e
MH
357void object_array_filter(struct object_array *array,
358 object_array_each_func_t want, void *cb_data)
b2a6d1c6 359{
aeb4a51e 360 unsigned nr = array->nr, src, dst;
b2a6d1c6
JH
361 struct object_array_entry *objects = array->objects;
362
aeb4a51e
MH
363 for (src = dst = 0; src < nr; src++) {
364 if (want(&objects[src], cb_data)) {
b2a6d1c6
JH
365 if (src != dst)
366 objects[dst] = objects[src];
367 dst++;
31faeb20 368 } else {
68f49235 369 object_array_release_entry(&objects[src]);
aeb4a51e
MH
370 }
371 }
372 array->nr = dst;
373}
374
46be8231
JK
375void object_array_clear(struct object_array *array)
376{
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;
383}
384
1506510c
MH
385/*
386 * Return true iff array already contains an entry with name.
387 */
388static int contains_name(struct object_array *array, const char *name)
389{
390 unsigned nr = array->nr, i;
391 struct object_array_entry *object = array->objects;
392
393 for (i = 0; i < nr; i++, object++)
394 if (!strcmp(object->name, name))
395 return 1;
396 return 0;
397}
398
b2a6d1c6
JH
399void object_array_remove_duplicates(struct object_array *array)
400{
1506510c 401 unsigned nr = array->nr, src;
b2a6d1c6
JH
402 struct object_array_entry *objects = array->objects;
403
1506510c
MH
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++;
31faeb20 410 } else {
68f49235 411 object_array_release_entry(&objects[src]);
b2a6d1c6 412 }
b2a6d1c6
JH
413 }
414}
bcc0a3ea
HV
415
416void clear_object_flags(unsigned flags)
417{
418 int i;
419
420 for (i=0; i < obj_hash_size; i++) {
421 struct object *obj = obj_hash[i];
422 if (obj)
423 obj->flags &= ~flags;
424 }
425}