convert object type handling from a string to a number
[git/git.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(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
46 static unsigned int hash_obj(struct object *obj, unsigned int n)
47 {
48 unsigned int hash = *(unsigned int *)obj->sha1;
49 return hash % n;
50 }
51
52 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
53 {
54 int j = hash_obj(obj, size);
55
56 while (hash[j]) {
57 j++;
58 if (j >= size)
59 j = 0;
60 }
61 hash[j] = obj;
62 }
63
64 static int hashtable_index(const unsigned char *sha1)
65 {
66 unsigned int i;
67 memcpy(&i, sha1, sizeof(unsigned int));
68 return (int)(i % obj_hash_size);
69 }
70
71 struct object *lookup_object(const unsigned char *sha1)
72 {
73 int i;
74 struct object *obj;
75
76 if (!obj_hash)
77 return NULL;
78
79 i = hashtable_index(sha1);
80 while ((obj = obj_hash[i]) != NULL) {
81 if (!hashcmp(sha1, obj->sha1))
82 break;
83 i++;
84 if (i == obj_hash_size)
85 i = 0;
86 }
87 return obj;
88 }
89
90 static void grow_object_hash(void)
91 {
92 int i;
93 int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
94 struct object **new_hash;
95
96 new_hash = xcalloc(new_hash_size, sizeof(struct object *));
97 for (i = 0; i < obj_hash_size; i++) {
98 struct object *obj = obj_hash[i];
99 if (!obj)
100 continue;
101 insert_obj_hash(obj, new_hash, new_hash_size);
102 }
103 free(obj_hash);
104 obj_hash = new_hash;
105 obj_hash_size = new_hash_size;
106 }
107
108 void created_object(const unsigned char *sha1, struct object *obj)
109 {
110 obj->parsed = 0;
111 obj->used = 0;
112 obj->type = OBJ_NONE;
113 obj->flags = 0;
114 hashcpy(obj->sha1, sha1);
115
116 if (obj_hash_size - 1 <= nr_objs * 2)
117 grow_object_hash();
118
119 insert_obj_hash(obj, obj_hash, obj_hash_size);
120 nr_objs++;
121 }
122
123 struct object *lookup_object_type(const unsigned char *sha1, const char *type)
124 {
125 if (!type) {
126 return lookup_unknown_object(sha1);
127 } else if (!strcmp(type, blob_type)) {
128 return &lookup_blob(sha1)->object;
129 } else if (!strcmp(type, tree_type)) {
130 return &lookup_tree(sha1)->object;
131 } else if (!strcmp(type, commit_type)) {
132 return &lookup_commit(sha1)->object;
133 } else if (!strcmp(type, tag_type)) {
134 return &lookup_tag(sha1)->object;
135 } else {
136 error("Unknown type %s", type);
137 return NULL;
138 }
139 }
140
141 union any_object {
142 struct object object;
143 struct commit commit;
144 struct tree tree;
145 struct blob blob;
146 struct tag tag;
147 };
148
149 struct object *lookup_unknown_object(const unsigned char *sha1)
150 {
151 struct object *obj = lookup_object(sha1);
152 if (!obj) {
153 union any_object *ret = xcalloc(1, sizeof(*ret));
154 created_object(sha1, &ret->object);
155 ret->object.type = OBJ_NONE;
156 return &ret->object;
157 }
158 return obj;
159 }
160
161 struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
162 {
163 struct object *obj;
164 int eaten = 0;
165
166 if (type == OBJ_BLOB) {
167 struct blob *blob = lookup_blob(sha1);
168 parse_blob_buffer(blob, buffer, size);
169 obj = &blob->object;
170 } else if (type == OBJ_TREE) {
171 struct tree *tree = lookup_tree(sha1);
172 obj = &tree->object;
173 if (!tree->object.parsed) {
174 parse_tree_buffer(tree, buffer, size);
175 eaten = 1;
176 }
177 } else if (type == OBJ_COMMIT) {
178 struct commit *commit = lookup_commit(sha1);
179 parse_commit_buffer(commit, buffer, size);
180 if (!commit->buffer) {
181 commit->buffer = buffer;
182 eaten = 1;
183 }
184 obj = &commit->object;
185 } else if (type == OBJ_TAG) {
186 struct tag *tag = lookup_tag(sha1);
187 parse_tag_buffer(tag, buffer, size);
188 obj = &tag->object;
189 } else {
190 obj = NULL;
191 }
192 *eaten_p = eaten;
193 return obj;
194 }
195
196 struct object *parse_object(const unsigned char *sha1)
197 {
198 unsigned long size;
199 enum object_type type;
200 int eaten;
201 void *buffer = read_sha1_file(sha1, &type, &size);
202
203 if (buffer) {
204 struct object *obj;
205 if (check_sha1_signature(sha1, buffer, size, typename(type)) < 0)
206 printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
207
208 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
209 if (!eaten)
210 free(buffer);
211 return obj;
212 }
213 return NULL;
214 }
215
216 struct object_list *object_list_insert(struct object *item,
217 struct object_list **list_p)
218 {
219 struct object_list *new_list = xmalloc(sizeof(struct object_list));
220 new_list->item = item;
221 new_list->next = *list_p;
222 *list_p = new_list;
223 return new_list;
224 }
225
226 void object_list_append(struct object *item,
227 struct object_list **list_p)
228 {
229 while (*list_p) {
230 list_p = &((*list_p)->next);
231 }
232 *list_p = xmalloc(sizeof(struct object_list));
233 (*list_p)->next = NULL;
234 (*list_p)->item = item;
235 }
236
237 unsigned object_list_length(struct object_list *list)
238 {
239 unsigned ret = 0;
240 while (list) {
241 list = list->next;
242 ret++;
243 }
244 return ret;
245 }
246
247 int object_list_contains(struct object_list *list, struct object *obj)
248 {
249 while (list) {
250 if (list->item == obj)
251 return 1;
252 list = list->next;
253 }
254 return 0;
255 }
256
257 void add_object_array(struct object *obj, const char *name, struct object_array *array)
258 {
259 unsigned nr = array->nr;
260 unsigned alloc = array->alloc;
261 struct object_array_entry *objects = array->objects;
262
263 if (nr >= alloc) {
264 alloc = (alloc + 32) * 2;
265 objects = xrealloc(objects, alloc * sizeof(*objects));
266 array->alloc = alloc;
267 array->objects = objects;
268 }
269 objects[nr].item = obj;
270 objects[nr].name = name;
271 array->nr = ++nr;
272 }