Shrink "struct object" a bit
[git/git.git] / tag.c
1 #include "cache.h"
2 #include "tag.h"
3
4 const char *tag_type = "tag";
5
6 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
7 {
8 while (o && o->type == TYPE_TAG)
9 o = parse_object(((struct tag *)o)->tagged->sha1);
10 if (!o && warn) {
11 if (!warnlen)
12 warnlen = strlen(warn);
13 error("missing object referenced by '%.*s'", warnlen, warn);
14 }
15 return o;
16 }
17
18 struct tag *lookup_tag(const unsigned char *sha1)
19 {
20 struct object *obj = lookup_object(sha1);
21 if (!obj) {
22 struct tag *ret = xcalloc(1, sizeof(struct tag));
23 created_object(sha1, &ret->object);
24 ret->object.type = TYPE_TAG;
25 return ret;
26 }
27 if (!obj->type)
28 obj->type = TYPE_TAG;
29 if (obj->type != TYPE_TAG) {
30 error("Object %s is a %s, not a tree",
31 sha1_to_hex(sha1), typename(obj->type));
32 return NULL;
33 }
34 return (struct tag *) obj;
35 }
36
37 int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
38 {
39 int typelen, taglen;
40 unsigned char object[20];
41 const char *type_line, *tag_line, *sig_line;
42 char type[20];
43
44 if (item->object.parsed)
45 return 0;
46 item->object.parsed = 1;
47
48 if (size < 64)
49 return -1;
50 if (memcmp("object ", data, 7) || get_sha1_hex(data + 7, object))
51 return -1;
52
53 type_line = data + 48;
54 if (memcmp("\ntype ", type_line-1, 6))
55 return -1;
56
57 tag_line = strchr(type_line, '\n');
58 if (!tag_line || memcmp("tag ", ++tag_line, 4))
59 return -1;
60
61 sig_line = strchr(tag_line, '\n');
62 if (!sig_line)
63 return -1;
64 sig_line++;
65
66 typelen = tag_line - type_line - strlen("type \n");
67 if (typelen >= 20)
68 return -1;
69 memcpy(type, type_line + 5, typelen);
70 type[typelen] = '\0';
71 taglen = sig_line - tag_line - strlen("tag \n");
72 item->tag = xmalloc(taglen + 1);
73 memcpy(item->tag, tag_line + 4, taglen);
74 item->tag[taglen] = '\0';
75
76 item->tagged = lookup_object_type(object, type);
77 if (item->tagged && track_object_refs) {
78 struct object_refs *refs = alloc_object_refs(1);
79 refs->ref[0] = item->tagged;
80 set_object_refs(&item->object, refs);
81 }
82
83 return 0;
84 }
85
86 int parse_tag(struct tag *item)
87 {
88 char type[20];
89 void *data;
90 unsigned long size;
91 int ret;
92
93 if (item->object.parsed)
94 return 0;
95 data = read_sha1_file(item->object.sha1, type, &size);
96 if (!data)
97 return error("Could not read %s",
98 sha1_to_hex(item->object.sha1));
99 if (strcmp(type, tag_type)) {
100 free(data);
101 return error("Object %s not a tag",
102 sha1_to_hex(item->object.sha1));
103 }
104 ret = parse_tag_buffer(item, data, size);
105 free(data);
106 return ret;
107 }