Libified diff-index: backward compatibility fix.
[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 struct object **objs;
9 static int nr_objs;
10 int obj_allocs;
11
12 int track_object_refs = 1;
13
14 static int hashtable_index(const unsigned char *sha1)
15 {
16         unsigned int i;
17         memcpy(&i, sha1, sizeof(unsigned int));
18         return (int)(i % obj_allocs);
19 }
20
21 static int find_object(const unsigned char *sha1)
22 {
23         int i;
24
25         if (!objs)
26                 return -1;
27
28         i = hashtable_index(sha1);
29         while (objs[i]) {
30                 if (memcmp(sha1, objs[i]->sha1, 20) == 0)
31                         return i;
32                 i++;
33                 if (i == obj_allocs)
34                         i = 0;
35         }
36         return -1 - i;
37 }
38
39 struct object *lookup_object(const unsigned char *sha1)
40 {
41         int pos = find_object(sha1);
42         if (pos >= 0)
43                 return objs[pos];
44         return NULL;
45 }
46
47 void created_object(const unsigned char *sha1, struct object *obj)
48 {
49         int pos;
50
51         obj->parsed = 0;
52         memcpy(obj->sha1, sha1, 20);
53         obj->type = NULL;
54         obj->refs = NULL;
55         obj->used = 0;
56
57         if (obj_allocs - 1 <= nr_objs * 2) {
58                 int i, count = obj_allocs;
59                 obj_allocs = (obj_allocs < 32 ? 32 : 2 * obj_allocs);
60                 objs = xrealloc(objs, obj_allocs * sizeof(struct object *));
61                 memset(objs + count, 0, (obj_allocs - count)
62                                 * sizeof(struct object *));
63                 for (i = 0; i < obj_allocs; i++)
64                         if (objs[i]) {
65                                 int j = find_object(objs[i]->sha1);
66                                 if (j != i) {
67                                         j = -1 - j;
68                                         objs[j] = objs[i];
69                                         objs[i] = NULL;
70                                 }
71                         }
72         }
73
74         pos = find_object(sha1);
75         if (pos >= 0)
76                 die("Inserting %s twice\n", sha1_to_hex(sha1));
77         pos = -pos-1;
78
79         objs[pos] = obj;
80         nr_objs++;
81 }
82
83 struct object_refs *alloc_object_refs(unsigned count)
84 {
85         struct object_refs *refs;
86         size_t size = sizeof(*refs) + count*sizeof(struct object *);
87
88         refs = xcalloc(1, size);
89         refs->count = count;
90         return refs;
91 }
92
93 static int compare_object_pointers(const void *a, const void *b)
94 {
95         const struct object * const *pa = a;
96         const struct object * const *pb = b;
97         if (*pa == *pb)
98                 return 0;
99         else if (*pa < *pb)
100                 return -1;
101         else
102                 return 1;
103 }
104
105 void set_object_refs(struct object *obj, struct object_refs *refs)
106 {
107         unsigned int i, j;
108
109         /* Do not install empty list of references */
110         if (refs->count < 1) {
111                 free(refs);
112                 return;
113         }
114
115         /* Sort the list and filter out duplicates */
116         qsort(refs->ref, refs->count, sizeof(refs->ref[0]),
117               compare_object_pointers);
118         for (i = j = 1; i < refs->count; i++) {
119                 if (refs->ref[i] != refs->ref[i - 1])
120                         refs->ref[j++] = refs->ref[i];
121         }
122         if (j < refs->count) {
123                 /* Duplicates were found - reallocate list */
124                 size_t size = sizeof(*refs) + j*sizeof(struct object *);
125                 refs->count = j;
126                 refs = xrealloc(refs, size);
127         }
128
129         for (i = 0; i < refs->count; i++)
130                 refs->ref[i]->used = 1;
131         obj->refs = refs;
132 }
133
134 void mark_reachable(struct object *obj, unsigned int mask)
135 {
136         if (!track_object_refs)
137                 die("cannot do reachability with object refs turned off");
138         /* If we've been here already, don't bother */
139         if (obj->flags & mask)
140                 return;
141         obj->flags |= mask;
142         if (obj->refs) {
143                 const struct object_refs *refs = obj->refs;
144                 unsigned i;
145                 for (i = 0; i < refs->count; i++)
146                         mark_reachable(refs->ref[i], mask);
147         }
148 }
149
150 struct object *lookup_object_type(const unsigned char *sha1, const char *type)
151 {
152         if (!type) {
153                 return lookup_unknown_object(sha1);
154         } else if (!strcmp(type, blob_type)) {
155                 return &lookup_blob(sha1)->object;
156         } else if (!strcmp(type, tree_type)) {
157                 return &lookup_tree(sha1)->object;
158         } else if (!strcmp(type, commit_type)) {
159                 return &lookup_commit(sha1)->object;
160         } else if (!strcmp(type, tag_type)) {
161                 return &lookup_tag(sha1)->object;
162         } else {
163                 error("Unknown type %s", type);
164                 return NULL;
165         }
166 }
167
168 union any_object {
169         struct object object;
170         struct commit commit;
171         struct tree tree;
172         struct blob blob;
173         struct tag tag;
174 };
175
176 struct object *lookup_unknown_object(const unsigned char *sha1)
177 {
178         struct object *obj = lookup_object(sha1);
179         if (!obj) {
180                 union any_object *ret = xcalloc(1, sizeof(*ret));
181                 created_object(sha1, &ret->object);
182                 ret->object.type = NULL;
183                 return &ret->object;
184         }
185         return obj;
186 }
187
188 struct object *parse_object(const unsigned char *sha1)
189 {
190         unsigned long size;
191         char type[20];
192         void *buffer = read_sha1_file(sha1, type, &size);
193         if (buffer) {
194                 struct object *obj;
195                 if (check_sha1_signature(sha1, buffer, size, type) < 0)
196                         printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
197                 if (!strcmp(type, blob_type)) {
198                         struct blob *blob = lookup_blob(sha1);
199                         parse_blob_buffer(blob, buffer, size);
200                         obj = &blob->object;
201                 } else if (!strcmp(type, tree_type)) {
202                         struct tree *tree = lookup_tree(sha1);
203                         parse_tree_buffer(tree, buffer, size);
204                         obj = &tree->object;
205                 } else if (!strcmp(type, commit_type)) {
206                         struct commit *commit = lookup_commit(sha1);
207                         parse_commit_buffer(commit, buffer, size);
208                         if (!commit->buffer) {
209                                 commit->buffer = buffer;
210                                 buffer = NULL;
211                         }
212                         obj = &commit->object;
213                 } else if (!strcmp(type, tag_type)) {
214                         struct tag *tag = lookup_tag(sha1);
215                         parse_tag_buffer(tag, buffer, size);
216                         obj = &tag->object;
217                 } else {
218                         obj = NULL;
219                 }
220                 free(buffer);
221                 return obj;
222         }
223         return NULL;
224 }
225
226 struct object_list *object_list_insert(struct object *item,
227                                        struct object_list **list_p)
228 {
229         struct object_list *new_list = xmalloc(sizeof(struct object_list));
230         new_list->item = item;
231         new_list->next = *list_p;
232         *list_p = new_list;
233         return new_list;
234 }
235
236 void object_list_append(struct object *item,
237                         struct object_list **list_p)
238 {
239         while (*list_p) {
240                 list_p = &((*list_p)->next);
241         }
242         *list_p = xmalloc(sizeof(struct object_list));
243         (*list_p)->next = NULL;
244         (*list_p)->item = item;
245 }
246
247 unsigned object_list_length(struct object_list *list)
248 {
249         unsigned ret = 0;
250         while (list) {
251                 list = list->next;
252                 ret++;
253         }
254         return ret;
255 }
256
257 int object_list_contains(struct object_list *list, struct object *obj)
258 {
259         while (list) {
260                 if (list->item == obj)
261                         return 1;
262                 list = list->next;
263         }
264         return 0;
265 }