Make "struct tree" contain the pointer to the tree buffer
[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 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 obj = &tree->object;
204 if (!tree->object.parsed) {
205 parse_tree_buffer(tree, buffer, size);
206 buffer = NULL;
207 }
208 } else if (!strcmp(type, commit_type)) {
209 struct commit *commit = lookup_commit(sha1);
210 parse_commit_buffer(commit, buffer, size);
211 if (!commit->buffer) {
212 commit->buffer = buffer;
213 buffer = NULL;
214 }
215 obj = &commit->object;
216 } else if (!strcmp(type, tag_type)) {
217 struct tag *tag = lookup_tag(sha1);
218 parse_tag_buffer(tag, buffer, size);
219 obj = &tag->object;
220 } else {
221 obj = NULL;
222 }
223 free(buffer);
224 return obj;
225 }
226 return NULL;
227 }
228
229 struct object_list *object_list_insert(struct object *item,
230 struct object_list **list_p)
231 {
232 struct object_list *new_list = xmalloc(sizeof(struct object_list));
233 new_list->item = item;
234 new_list->next = *list_p;
235 *list_p = new_list;
236 return new_list;
237 }
238
239 void object_list_append(struct object *item,
240 struct object_list **list_p)
241 {
242 while (*list_p) {
243 list_p = &((*list_p)->next);
244 }
245 *list_p = xmalloc(sizeof(struct object_list));
246 (*list_p)->next = NULL;
247 (*list_p)->item = item;
248 }
249
250 unsigned object_list_length(struct object_list *list)
251 {
252 unsigned ret = 0;
253 while (list) {
254 list = list->next;
255 ret++;
256 }
257 return ret;
258 }
259
260 int object_list_contains(struct object_list *list, struct object *obj)
261 {
262 while (list) {
263 if (list->item == obj)
264 return 1;
265 list = list->next;
266 }
267 return 0;
268 }