Add git-for-each-ref: helper for language bindings
[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 const char *type_names[] = {
22 "none", "commit", "tree", "blob", "tag",
23 "bad type 5", "bad type 6", "delta", "bad",
24 };
25
26 static unsigned int hash_obj(struct object *obj, unsigned int n)
27 {
28 unsigned int hash = *(unsigned int *)obj->sha1;
29 return hash % n;
30 }
31
32 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
33 {
34 int j = hash_obj(obj, size);
35
36 while (hash[j]) {
37 j++;
38 if (j >= size)
39 j = 0;
40 }
41 hash[j] = obj;
42 }
43
44 static int hashtable_index(const unsigned char *sha1)
45 {
46 unsigned int i;
47 memcpy(&i, sha1, sizeof(unsigned int));
48 return (int)(i % obj_hash_size);
49 }
50
51 struct object *lookup_object(const unsigned char *sha1)
52 {
53 int i;
54 struct object *obj;
55
56 if (!obj_hash)
57 return NULL;
58
59 i = hashtable_index(sha1);
60 while ((obj = obj_hash[i]) != NULL) {
61 if (!hashcmp(sha1, obj->sha1))
62 break;
63 i++;
64 if (i == obj_hash_size)
65 i = 0;
66 }
67 return obj;
68 }
69
70 static void grow_object_hash(void)
71 {
72 int i;
73 int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
74 struct object **new_hash;
75
76 new_hash = xcalloc(new_hash_size, sizeof(struct object *));
77 for (i = 0; i < obj_hash_size; i++) {
78 struct object *obj = obj_hash[i];
79 if (!obj)
80 continue;
81 insert_obj_hash(obj, new_hash, new_hash_size);
82 }
83 free(obj_hash);
84 obj_hash = new_hash;
85 obj_hash_size = new_hash_size;
86 }
87
88 void created_object(const unsigned char *sha1, struct object *obj)
89 {
90 obj->parsed = 0;
91 obj->used = 0;
92 obj->type = OBJ_NONE;
93 obj->flags = 0;
94 hashcpy(obj->sha1, sha1);
95
96 if (obj_hash_size - 1 <= nr_objs * 2)
97 grow_object_hash();
98
99 insert_obj_hash(obj, obj_hash, obj_hash_size);
100 nr_objs++;
101 }
102
103 struct object *lookup_object_type(const unsigned char *sha1, const char *type)
104 {
105 if (!type) {
106 return lookup_unknown_object(sha1);
107 } else if (!strcmp(type, blob_type)) {
108 return &lookup_blob(sha1)->object;
109 } else if (!strcmp(type, tree_type)) {
110 return &lookup_tree(sha1)->object;
111 } else if (!strcmp(type, commit_type)) {
112 return &lookup_commit(sha1)->object;
113 } else if (!strcmp(type, tag_type)) {
114 return &lookup_tag(sha1)->object;
115 } else {
116 error("Unknown type %s", type);
117 return NULL;
118 }
119 }
120
121 union any_object {
122 struct object object;
123 struct commit commit;
124 struct tree tree;
125 struct blob blob;
126 struct tag tag;
127 };
128
129 struct object *lookup_unknown_object(const unsigned char *sha1)
130 {
131 struct object *obj = lookup_object(sha1);
132 if (!obj) {
133 union any_object *ret = xcalloc(1, sizeof(*ret));
134 created_object(sha1, &ret->object);
135 ret->object.type = OBJ_NONE;
136 return &ret->object;
137 }
138 return obj;
139 }
140
141 struct object *parse_object_buffer(const unsigned char *sha1, const char *type, unsigned long size, void *buffer, int *eaten_p)
142 {
143 struct object *obj;
144 int eaten = 0;
145
146 if (!strcmp(type, blob_type)) {
147 struct blob *blob = lookup_blob(sha1);
148 parse_blob_buffer(blob, buffer, size);
149 obj = &blob->object;
150 } else if (!strcmp(type, tree_type)) {
151 struct tree *tree = lookup_tree(sha1);
152 obj = &tree->object;
153 if (!tree->object.parsed) {
154 parse_tree_buffer(tree, buffer, size);
155 eaten = 1;
156 }
157 } else if (!strcmp(type, commit_type)) {
158 struct commit *commit = lookup_commit(sha1);
159 parse_commit_buffer(commit, buffer, size);
160 if (!commit->buffer) {
161 commit->buffer = buffer;
162 eaten = 1;
163 }
164 obj = &commit->object;
165 } else if (!strcmp(type, tag_type)) {
166 struct tag *tag = lookup_tag(sha1);
167 parse_tag_buffer(tag, buffer, size);
168 obj = &tag->object;
169 } else {
170 obj = NULL;
171 }
172 *eaten_p = eaten;
173 return obj;
174 }
175
176 struct object *parse_object(const unsigned char *sha1)
177 {
178 unsigned long size;
179 char type[20];
180 int eaten;
181 void *buffer = read_sha1_file(sha1, type, &size);
182
183 if (buffer) {
184 struct object *obj;
185 if (check_sha1_signature(sha1, buffer, size, type) < 0)
186 printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
187
188 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
189 if (!eaten)
190 free(buffer);
191 return obj;
192 }
193 return NULL;
194 }
195
196 struct object_list *object_list_insert(struct object *item,
197 struct object_list **list_p)
198 {
199 struct object_list *new_list = xmalloc(sizeof(struct object_list));
200 new_list->item = item;
201 new_list->next = *list_p;
202 *list_p = new_list;
203 return new_list;
204 }
205
206 void object_list_append(struct object *item,
207 struct object_list **list_p)
208 {
209 while (*list_p) {
210 list_p = &((*list_p)->next);
211 }
212 *list_p = xmalloc(sizeof(struct object_list));
213 (*list_p)->next = NULL;
214 (*list_p)->item = item;
215 }
216
217 unsigned object_list_length(struct object_list *list)
218 {
219 unsigned ret = 0;
220 while (list) {
221 list = list->next;
222 ret++;
223 }
224 return ret;
225 }
226
227 int object_list_contains(struct object_list *list, struct object *obj)
228 {
229 while (list) {
230 if (list->item == obj)
231 return 1;
232 list = list->next;
233 }
234 return 0;
235 }
236
237 void add_object_array(struct object *obj, const char *name, struct object_array *array)
238 {
239 unsigned nr = array->nr;
240 unsigned alloc = array->alloc;
241 struct object_array_entry *objects = array->objects;
242
243 if (nr >= alloc) {
244 alloc = (alloc + 32) * 2;
245 objects = xrealloc(objects, alloc * sizeof(*objects));
246 array->alloc = alloc;
247 array->objects = objects;
248 }
249 objects[nr].item = obj;
250 objects[nr].name = name;
251 array->nr = ++nr;
252 }