git.el: More robust handling of subprocess errors when returning strings.
[alt-git.git] / object.c
blobc9ca481498281adab056a364a3854180456f20f3
1 #include "cache.h"
2 #include "object.h"
3 #include "blob.h"
4 #include "tree.h"
5 #include "commit.h"
6 #include "tag.h"
8 struct object **objs;
9 static int nr_objs;
10 int obj_allocs;
12 int track_object_refs = 1;
14 static int hashtable_index(const unsigned char *sha1)
16 unsigned int i;
17 memcpy(&i, sha1, sizeof(unsigned int));
18 return (int)(i % obj_allocs);
21 static int find_object(const unsigned char *sha1)
23 int i;
25 if (!objs)
26 return -1;
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;
36 return -1 - i;
39 struct object *lookup_object(const unsigned char *sha1)
41 int pos = find_object(sha1);
42 if (pos >= 0)
43 return objs[pos];
44 return NULL;
47 void created_object(const unsigned char *sha1, struct object *obj)
49 int pos;
51 obj->parsed = 0;
52 memcpy(obj->sha1, sha1, 20);
53 obj->type = NULL;
54 obj->refs = NULL;
55 obj->used = 0;
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;
74 pos = find_object(sha1);
75 if (pos >= 0)
76 die("Inserting %s twice\n", sha1_to_hex(sha1));
77 pos = -pos-1;
79 objs[pos] = obj;
80 nr_objs++;
83 struct object_refs *alloc_object_refs(unsigned count)
85 struct object_refs *refs;
86 size_t size = sizeof(*refs) + count*sizeof(struct object *);
88 refs = xmalloc(size);
89 memset(refs, 0, size);
90 refs->count = count;
91 return refs;
94 static int compare_object_pointers(const void *a, const void *b)
96 const struct object * const *pa = a;
97 const struct object * const *pb = b;
98 if (*pa == *pb)
99 return 0;
100 else if (*pa < *pb)
101 return -1;
102 else
103 return 1;
106 void set_object_refs(struct object *obj, struct object_refs *refs)
108 unsigned int i, j;
110 /* Do not install empty list of references */
111 if (refs->count < 1) {
112 free(refs);
113 return;
116 /* Sort the list and filter out duplicates */
117 qsort(refs->ref, refs->count, sizeof(refs->ref[0]),
118 compare_object_pointers);
119 for (i = j = 1; i < refs->count; i++) {
120 if (refs->ref[i] != refs->ref[i - 1])
121 refs->ref[j++] = refs->ref[i];
123 if (j < refs->count) {
124 /* Duplicates were found - reallocate list */
125 size_t size = sizeof(*refs) + j*sizeof(struct object *);
126 refs->count = j;
127 refs = xrealloc(refs, size);
130 for (i = 0; i < refs->count; i++)
131 refs->ref[i]->used = 1;
132 obj->refs = refs;
135 void mark_reachable(struct object *obj, unsigned int mask)
137 if (!track_object_refs)
138 die("cannot do reachability with object refs turned off");
139 /* If we've been here already, don't bother */
140 if (obj->flags & mask)
141 return;
142 obj->flags |= mask;
143 if (obj->refs) {
144 const struct object_refs *refs = obj->refs;
145 unsigned i;
146 for (i = 0; i < refs->count; i++)
147 mark_reachable(refs->ref[i], mask);
151 struct object *lookup_object_type(const unsigned char *sha1, const char *type)
153 if (!type) {
154 return lookup_unknown_object(sha1);
155 } else if (!strcmp(type, blob_type)) {
156 return &lookup_blob(sha1)->object;
157 } else if (!strcmp(type, tree_type)) {
158 return &lookup_tree(sha1)->object;
159 } else if (!strcmp(type, commit_type)) {
160 return &lookup_commit(sha1)->object;
161 } else if (!strcmp(type, tag_type)) {
162 return &lookup_tag(sha1)->object;
163 } else {
164 error("Unknown type %s", type);
165 return NULL;
169 union any_object {
170 struct object object;
171 struct commit commit;
172 struct tree tree;
173 struct blob blob;
174 struct tag tag;
177 struct object *lookup_unknown_object(const unsigned char *sha1)
179 struct object *obj = lookup_object(sha1);
180 if (!obj) {
181 union any_object *ret = xmalloc(sizeof(*ret));
182 memset(ret, 0, sizeof(*ret));
183 created_object(sha1, &ret->object);
184 ret->object.type = NULL;
185 return &ret->object;
187 return obj;
190 struct object *parse_object(const unsigned char *sha1)
192 unsigned long size;
193 char type[20];
194 void *buffer = read_sha1_file(sha1, type, &size);
195 if (buffer) {
196 struct object *obj;
197 if (check_sha1_signature(sha1, buffer, size, type) < 0)
198 printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
199 if (!strcmp(type, "blob")) {
200 struct blob *blob = lookup_blob(sha1);
201 parse_blob_buffer(blob, buffer, size);
202 obj = &blob->object;
203 } else if (!strcmp(type, "tree")) {
204 struct tree *tree = lookup_tree(sha1);
205 parse_tree_buffer(tree, buffer, size);
206 obj = &tree->object;
207 } else if (!strcmp(type, "commit")) {
208 struct commit *commit = lookup_commit(sha1);
209 parse_commit_buffer(commit, buffer, size);
210 if (!commit->buffer) {
211 commit->buffer = buffer;
212 buffer = NULL;
214 obj = &commit->object;
215 } else if (!strcmp(type, "tag")) {
216 struct tag *tag = lookup_tag(sha1);
217 parse_tag_buffer(tag, buffer, size);
218 obj = &tag->object;
219 } else {
220 obj = NULL;
222 free(buffer);
223 return obj;
225 return NULL;
228 struct object_list *object_list_insert(struct object *item,
229 struct object_list **list_p)
231 struct object_list *new_list = xmalloc(sizeof(struct object_list));
232 new_list->item = item;
233 new_list->next = *list_p;
234 *list_p = new_list;
235 return new_list;
238 void object_list_append(struct object *item,
239 struct object_list **list_p)
241 while (*list_p) {
242 list_p = &((*list_p)->next);
244 *list_p = xmalloc(sizeof(struct object_list));
245 (*list_p)->next = NULL;
246 (*list_p)->item = item;
249 unsigned object_list_length(struct object_list *list)
251 unsigned ret = 0;
252 while (list) {
253 list = list->next;
254 ret++;
256 return ret;
259 int object_list_contains(struct object_list *list, struct object *obj)
261 while (list) {
262 if (list->item == obj)
263 return 1;
264 list = list->next;
266 return 0;