Update draft release notes to 2.2
[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
36int 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
33bef7ea
MH
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 */
9f36c9b7 51static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
0556a11a 52{
039dc71a 53 return sha1hash(sha1) & (n - 1);
0556a11a
LT
54}
55
33bef7ea
MH
56/*
57 * Insert obj into the hash table hash, which has length size (which
58 * must be a power of 2). On collisions, simply overflow to the next
59 * empty bucket.
60 */
0556a11a
LT
61static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
62{
9f36c9b7 63 unsigned int j = hash_obj(obj->sha1, size);
0556a11a
LT
64
65 while (hash[j]) {
66 j++;
67 if (j >= size)
68 j = 0;
69 }
70 hash[j] = obj;
71}
72
33bef7ea
MH
73/*
74 * Look up the record for the given sha1 in the hash map stored in
75 * obj_hash. Return NULL if it was not found.
76 */
0556a11a 77struct object *lookup_object(const unsigned char *sha1)
175785e5 78{
9a414486 79 unsigned int i, first;
0556a11a 80 struct object *obj;
175785e5 81
0556a11a
LT
82 if (!obj_hash)
83 return NULL;
175785e5 84
9f36c9b7 85 first = i = hash_obj(sha1, obj_hash_size);
0556a11a 86 while ((obj = obj_hash[i]) != NULL) {
a89fccd2 87 if (!hashcmp(sha1, obj->sha1))
0556a11a 88 break;
070879ca 89 i++;
0556a11a 90 if (i == obj_hash_size)
070879ca
JS
91 i = 0;
92 }
9a414486
JK
93 if (obj && i != first) {
94 /*
95 * Move object to where we started to look for it so
96 * that we do not need to walk the hash table the next
97 * time we look for it.
98 */
99 struct object *tmp = obj_hash[i];
100 obj_hash[i] = obj_hash[first];
101 obj_hash[first] = tmp;
102 }
0556a11a 103 return obj;
175785e5
DB
104}
105
33bef7ea
MH
106/*
107 * Increase the size of the hash map stored in obj_hash to the next
108 * power of 2 (but at least 32). Copy the existing values to the new
109 * hash map.
110 */
0556a11a 111static void grow_object_hash(void)
175785e5 112{
0556a11a 113 int i;
9f36c9b7
NP
114 /*
115 * Note that this size must always be power-of-2 to match hash_obj
116 * above.
117 */
0556a11a
LT
118 int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
119 struct object **new_hash;
120
b3c952f8 121 new_hash = xcalloc(new_hash_size, sizeof(struct object *));
0556a11a
LT
122 for (i = 0; i < obj_hash_size; i++) {
123 struct object *obj = obj_hash[i];
124 if (!obj)
125 continue;
126 insert_obj_hash(obj, new_hash, new_hash_size);
127 }
128 free(obj_hash);
129 obj_hash = new_hash;
130 obj_hash_size = new_hash_size;
175785e5
DB
131}
132
d36f51c1 133void *create_object(const unsigned char *sha1, void *o)
175785e5 134{
100c5f3b
LT
135 struct object *obj = o;
136
175785e5 137 obj->parsed = 0;
175785e5 138 obj->used = 0;
0556a11a 139 obj->flags = 0;
e702496e 140 hashcpy(obj->sha1, sha1);
175785e5 141
0556a11a
LT
142 if (obj_hash_size - 1 <= nr_objs * 2)
143 grow_object_hash();
175785e5 144
0556a11a 145 insert_obj_hash(obj, obj_hash, obj_hash_size);
175785e5 146 nr_objs++;
100c5f3b 147 return obj;
175785e5
DB
148}
149
8ff226a9
JK
150void *object_as_type(struct object *obj, enum object_type type, int quiet)
151{
152 if (obj->type == type)
153 return obj;
154 else if (obj->type == OBJ_NONE) {
d66bebcb
JK
155 if (type == OBJ_COMMIT)
156 ((struct commit *)obj)->index = alloc_commit_index();
8ff226a9
JK
157 obj->type = type;
158 return obj;
159 }
160 else {
161 if (!quiet)
162 error("object %s is a %s, not a %s",
163 sha1_to_hex(obj->sha1),
164 typename(obj->type), typename(type));
165 return NULL;
166 }
167}
168
66e481b0
DB
169struct object *lookup_unknown_object(const unsigned char *sha1)
170{
171 struct object *obj = lookup_object(sha1);
100c5f3b 172 if (!obj)
d36f51c1 173 obj = create_object(sha1, alloc_object_node());
66e481b0
DB
174 return obj;
175}
176
21666f1a 177struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
9f613ddd
JH
178{
179 struct object *obj;
8e92e8f2 180 *eaten_p = 0;
9f613ddd 181
cc216827 182 obj = NULL;
21666f1a 183 if (type == OBJ_BLOB) {
9f613ddd 184 struct blob *blob = lookup_blob(sha1);
cc216827 185 if (blob) {
d0b8c9e5
MK
186 if (parse_blob_buffer(blob, buffer, size))
187 return NULL;
cc216827
JM
188 obj = &blob->object;
189 }
21666f1a 190 } else if (type == OBJ_TREE) {
9f613ddd 191 struct tree *tree = lookup_tree(sha1);
cc216827
JM
192 if (tree) {
193 obj = &tree->object;
68be2fea
JH
194 if (!tree->buffer)
195 tree->object.parsed = 0;
cc216827 196 if (!tree->object.parsed) {
d0b8c9e5
MK
197 if (parse_tree_buffer(tree, buffer, size))
198 return NULL;
8e92e8f2 199 *eaten_p = 1;
cc216827 200 }
9f613ddd 201 }
21666f1a 202 } else if (type == OBJ_COMMIT) {
9f613ddd 203 struct commit *commit = lookup_commit(sha1);
cc216827 204 if (commit) {
d0b8c9e5
MK
205 if (parse_commit_buffer(commit, buffer, size))
206 return NULL;
8597ea3a
JK
207 if (!get_cached_commit_buffer(commit, NULL)) {
208 set_commit_buffer(commit, buffer, size);
8e92e8f2 209 *eaten_p = 1;
cc216827
JM
210 }
211 obj = &commit->object;
9f613ddd 212 }
21666f1a 213 } else if (type == OBJ_TAG) {
9f613ddd 214 struct tag *tag = lookup_tag(sha1);
cc216827 215 if (tag) {
d0b8c9e5
MK
216 if (parse_tag_buffer(tag, buffer, size))
217 return NULL;
cc216827
JM
218 obj = &tag->object;
219 }
9f613ddd 220 } else {
82247e9b 221 warning("object %s has unknown type id %d", sha1_to_hex(sha1), type);
9f613ddd
JH
222 obj = NULL;
223 }
9f613ddd
JH
224 return obj;
225}
226
75a95490
JK
227struct object *parse_object_or_die(const unsigned char *sha1,
228 const char *name)
229{
230 struct object *o = parse_object(sha1);
231 if (o)
232 return o;
233
234 die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1));
235}
236
5d6ccf5c 237struct object *parse_object(const unsigned char *sha1)
e9eefa67 238{
c4584ae3 239 unsigned long size;
21666f1a 240 enum object_type type;
9f613ddd 241 int eaten;
4bbf5a26 242 const unsigned char *repl = lookup_replace_object(sha1);
ccdc6037
JK
243 void *buffer;
244 struct object *obj;
245
246 obj = lookup_object(sha1);
247 if (obj && obj->parsed)
248 return obj;
9f613ddd 249
090ea126
NTND
250 if ((obj && obj->type == OBJ_BLOB) ||
251 (!obj && has_sha1_file(sha1) &&
252 sha1_object_info(sha1, NULL) == OBJ_BLOB)) {
253 if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
82247e9b 254 error("sha1 mismatch %s", sha1_to_hex(repl));
090ea126
NTND
255 return NULL;
256 }
257 parse_blob_buffer(lookup_blob(sha1), NULL, 0);
258 return lookup_object(sha1);
259 }
260
ccdc6037 261 buffer = read_sha1_file(sha1, &type, &size);
c4584ae3 262 if (buffer) {
0e87c367 263 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
0b1f1130 264 free(buffer);
82247e9b 265 error("sha1 mismatch %s", sha1_to_hex(repl));
acdeec62
LT
266 return NULL;
267 }
9f613ddd 268
2e3400c0 269 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
9f613ddd
JH
270 if (!eaten)
271 free(buffer);
bd2c39f5 272 return obj;
e9eefa67
DB
273 }
274 return NULL;
275}
66e481b0
DB
276
277struct object_list *object_list_insert(struct object *item,
278 struct object_list **list_p)
279{
280 struct object_list *new_list = xmalloc(sizeof(struct object_list));
55b4e9e4
JH
281 new_list->item = item;
282 new_list->next = *list_p;
283 *list_p = new_list;
284 return new_list;
66e481b0
DB
285}
286
66e481b0
DB
287int object_list_contains(struct object_list *list, struct object *obj)
288{
289 while (list) {
290 if (list->item == obj)
291 return 1;
292 list = list->next;
293 }
294 return 0;
295}
1f1e895f 296
31faeb20
MH
297/*
298 * A zero-length string to which object_array_entry::name can be
299 * initialized without requiring a malloc/free.
300 */
301static char object_array_slopbuf[1];
302
4197361e
JH
303static void add_object_array_with_mode_context(struct object *obj, const char *name,
304 struct object_array *array,
305 unsigned mode,
306 struct object_context *context)
1f1e895f
LT
307{
308 unsigned nr = array->nr;
309 unsigned alloc = array->alloc;
310 struct object_array_entry *objects = array->objects;
31faeb20 311 struct object_array_entry *entry;
1f1e895f
LT
312
313 if (nr >= alloc) {
314 alloc = (alloc + 32) * 2;
315 objects = xrealloc(objects, alloc * sizeof(*objects));
316 array->alloc = alloc;
317 array->objects = objects;
318 }
31faeb20
MH
319 entry = &objects[nr];
320 entry->item = obj;
321 if (!name)
322 entry->name = NULL;
323 else if (!*name)
324 /* Use our own empty string instead of allocating one: */
325 entry->name = object_array_slopbuf;
326 else
327 entry->name = xstrdup(name);
328 entry->mode = mode;
4197361e 329 entry->context = context;
1f1e895f
LT
330 array->nr = ++nr;
331}
b2a6d1c6 332
afa15f3c
MG
333void add_object_array(struct object *obj, const char *name, struct object_array *array)
334{
335 add_object_array_with_mode(obj, name, array, S_IFINVALID);
336}
337
338void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
339{
340 add_object_array_with_mode_context(obj, name, array, mode, NULL);
341}
342
343void add_object_array_with_context(struct object *obj, const char *name, struct object_array *array, struct object_context *context)
344{
345 if (context)
346 add_object_array_with_mode_context(obj, name, array, context->mode, context);
347 else
348 add_object_array_with_mode_context(obj, name, array, S_IFINVALID, context);
349}
350
aeb4a51e
MH
351void object_array_filter(struct object_array *array,
352 object_array_each_func_t want, void *cb_data)
b2a6d1c6 353{
aeb4a51e 354 unsigned nr = array->nr, src, dst;
b2a6d1c6
JH
355 struct object_array_entry *objects = array->objects;
356
aeb4a51e
MH
357 for (src = dst = 0; src < nr; src++) {
358 if (want(&objects[src], cb_data)) {
b2a6d1c6
JH
359 if (src != dst)
360 objects[dst] = objects[src];
361 dst++;
31faeb20
MH
362 } else {
363 if (objects[src].name != object_array_slopbuf)
364 free(objects[src].name);
aeb4a51e
MH
365 }
366 }
367 array->nr = dst;
368}
369
1506510c
MH
370/*
371 * Return true iff array already contains an entry with name.
372 */
373static int contains_name(struct object_array *array, const char *name)
374{
375 unsigned nr = array->nr, i;
376 struct object_array_entry *object = array->objects;
377
378 for (i = 0; i < nr; i++, object++)
379 if (!strcmp(object->name, name))
380 return 1;
381 return 0;
382}
383
b2a6d1c6
JH
384void object_array_remove_duplicates(struct object_array *array)
385{
1506510c 386 unsigned nr = array->nr, src;
b2a6d1c6
JH
387 struct object_array_entry *objects = array->objects;
388
1506510c
MH
389 array->nr = 0;
390 for (src = 0; src < nr; src++) {
391 if (!contains_name(array, objects[src].name)) {
392 if (src != array->nr)
393 objects[array->nr] = objects[src];
394 array->nr++;
31faeb20
MH
395 } else {
396 if (objects[src].name != object_array_slopbuf)
397 free(objects[src].name);
b2a6d1c6 398 }
b2a6d1c6
JH
399 }
400}
bcc0a3ea
HV
401
402void clear_object_flags(unsigned flags)
403{
404 int i;
405
406 for (i=0; i < obj_hash_size; i++) {
407 struct object *obj = obj_hash[i];
408 if (obj)
409 obj->flags &= ~flags;
410 }
411}