Merge branch 'jk/skip-http-tests-under-no-curl' into maint
[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(obj->sha1, 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, obj->sha1))
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(obj->sha1, 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                               sha1_to_hex(obj->sha1),
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 }