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[git] / object.c
1 #include "object.h"
2 #include "blob.h"
3 #include "tree.h"
4 #include "commit.h"
5 #include "cache.h"
6 #include "tag.h"
7
8 struct object **objs;
9 int nr_objs;
10 static int obj_allocs;
11
12 int track_object_refs = 1;
13
14 static int find_object(const unsigned char *sha1)
15 {
16         int first = 0, last = nr_objs;
17
18         while (first < last) {
19                 int next = (first + last) / 2;
20                 struct object *obj = objs[next];
21                 int cmp;
22
23                 cmp = memcmp(sha1, obj->sha1, 20);
24                 if (!cmp)
25                         return next;
26                 if (cmp < 0) {
27                         last = next;
28                         continue;
29                 }
30                 first = next+1;
31         }
32         return -first-1;
33 }
34
35 struct object *lookup_object(const unsigned char *sha1)
36 {
37         int pos = find_object(sha1);
38         if (pos >= 0)
39                 return objs[pos];
40         return NULL;
41 }
42
43 void created_object(const unsigned char *sha1, struct object *obj)
44 {
45         int pos = find_object(sha1);
46
47         obj->parsed = 0;
48         memcpy(obj->sha1, sha1, 20);
49         obj->type = NULL;
50         obj->refs = NULL;
51         obj->used = 0;
52
53         if (pos >= 0)
54                 die("Inserting %s twice\n", sha1_to_hex(sha1));
55         pos = -pos-1;
56
57         if (obj_allocs == nr_objs) {
58                 obj_allocs = alloc_nr(obj_allocs);
59                 objs = xrealloc(objs, obj_allocs * sizeof(struct object *));
60         }
61
62         /* Insert it into the right place */
63         memmove(objs + pos + 1, objs + pos, (nr_objs - pos) * 
64                 sizeof(struct object *));
65
66         objs[pos] = obj;
67         nr_objs++;
68 }
69
70 void add_ref(struct object *refer, struct object *target)
71 {
72         struct object_list **pp, *p;
73
74         if (!track_object_refs)
75                 return;
76
77         pp = &refer->refs;
78         while ((p = *pp) != NULL) {
79                 if (p->item == target)
80                         return;
81                 pp = &p->next;
82         }
83
84         target->used = 1;
85         p = xmalloc(sizeof(*p));
86         p->item = target;
87         p->next = NULL;
88         *pp = p;
89 }
90
91 void mark_reachable(struct object *obj, unsigned int mask)
92 {
93         struct object_list *p = obj->refs;
94
95         if (!track_object_refs)
96                 die("cannot do reachability with object refs turned off");
97         /* If we've been here already, don't bother */
98         if (obj->flags & mask)
99                 return;
100         obj->flags |= mask;
101         while (p) {
102                 mark_reachable(p->item, mask);
103                 p = p->next;
104         }
105 }
106
107 struct object *lookup_object_type(const unsigned char *sha1, const char *type)
108 {
109         if (!type) {
110                 return lookup_unknown_object(sha1);
111         } else if (!strcmp(type, blob_type)) {
112                 return &lookup_blob(sha1)->object;
113         } else if (!strcmp(type, tree_type)) {
114                 return &lookup_tree(sha1)->object;
115         } else if (!strcmp(type, commit_type)) {
116                 return &lookup_commit(sha1)->object;
117         } else if (!strcmp(type, tag_type)) {
118                 return &lookup_tag(sha1)->object;
119         } else {
120                 error("Unknown type %s", type);
121                 return NULL;
122         }
123 }
124
125 union any_object {
126         struct object object;
127         struct commit commit;
128         struct tree tree;
129         struct blob blob;
130         struct tag tag;
131 };
132
133 struct object *lookup_unknown_object(const unsigned char *sha1)
134 {
135         struct object *obj = lookup_object(sha1);
136         if (!obj) {
137                 union any_object *ret = xmalloc(sizeof(*ret));
138                 memset(ret, 0, sizeof(*ret));
139                 created_object(sha1, &ret->object);
140                 ret->object.type = NULL;
141                 return &ret->object;
142         }
143         return obj;
144 }
145
146 struct object *parse_object(const unsigned char *sha1)
147 {
148         unsigned long size;
149         char type[20];
150         void *buffer = read_sha1_file(sha1, type, &size);
151         if (buffer) {
152                 struct object *obj;
153                 if (check_sha1_signature(sha1, buffer, size, type) < 0)
154                         printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
155                 if (!strcmp(type, "blob")) {
156                         struct blob *blob = lookup_blob(sha1);
157                         parse_blob_buffer(blob, buffer, size);
158                         obj = &blob->object;
159                 } else if (!strcmp(type, "tree")) {
160                         struct tree *tree = lookup_tree(sha1);
161                         parse_tree_buffer(tree, buffer, size);
162                         obj = &tree->object;
163                 } else if (!strcmp(type, "commit")) {
164                         struct commit *commit = lookup_commit(sha1);
165                         parse_commit_buffer(commit, buffer, size);
166                         if (!commit->buffer) {
167                                 commit->buffer = buffer;
168                                 buffer = NULL;
169                         }
170                         obj = &commit->object;
171                 } else if (!strcmp(type, "tag")) {
172                         struct tag *tag = lookup_tag(sha1);
173                         parse_tag_buffer(tag, buffer, size);
174                         obj = &tag->object;
175                 } else {
176                         obj = NULL;
177                 }
178                 free(buffer);
179                 return obj;
180         }
181         return NULL;
182 }
183
184 struct object_list *object_list_insert(struct object *item,
185                                        struct object_list **list_p)
186 {
187         struct object_list *new_list = xmalloc(sizeof(struct object_list));
188         new_list->item = item;
189         new_list->next = *list_p;
190         *list_p = new_list;
191         return new_list;
192 }
193
194 void object_list_append(struct object *item,
195                         struct object_list **list_p)
196 {
197         while (*list_p) {
198                 list_p = &((*list_p)->next);
199         }
200         *list_p = xmalloc(sizeof(struct object_list));
201         (*list_p)->next = NULL;
202         (*list_p)->item = item;
203 }
204
205 unsigned object_list_length(struct object_list *list)
206 {
207         unsigned ret = 0;
208         while (list) {
209                 list = list->next;
210                 ret++;
211         }
212         return ret;
213 }
214
215 int object_list_contains(struct object_list *list, struct object *obj)
216 {
217         while (list) {
218                 if (list->item == obj)
219                         return 1;
220                 list = list->next;
221         }
222         return 0;
223 }