Clean up object creation to use more common code
[git/git.git] / tag.c
1 #include "cache.h"
2 #include "tag.h"
3 #include "commit.h"
4 #include "tree.h"
5 #include "blob.h"
6
7 const char *tag_type = "tag";
8
9 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
10 {
11 while (o && o->type == OBJ_TAG)
12 o = parse_object(((struct tag *)o)->tagged->sha1);
13 if (!o && warn) {
14 if (!warnlen)
15 warnlen = strlen(warn);
16 error("missing object referenced by '%.*s'", warnlen, warn);
17 }
18 return o;
19 }
20
21 struct tag *lookup_tag(const unsigned char *sha1)
22 {
23 struct object *obj = lookup_object(sha1);
24 if (!obj)
25 return create_object(sha1, OBJ_TAG, alloc_tag_node());
26 if (!obj->type)
27 obj->type = OBJ_TAG;
28 if (obj->type != OBJ_TAG) {
29 error("Object %s is a %s, not a tree",
30 sha1_to_hex(sha1), typename(obj->type));
31 return NULL;
32 }
33 return (struct tag *) obj;
34 }
35
36 int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
37 {
38 int typelen, taglen;
39 unsigned char sha1[20];
40 const char *type_line, *tag_line, *sig_line;
41 char type[20];
42
43 if (item->object.parsed)
44 return 0;
45 item->object.parsed = 1;
46
47 if (size < 64)
48 return -1;
49 if (memcmp("object ", data, 7) || get_sha1_hex((char *) data + 7, sha1))
50 return -1;
51
52 type_line = (char *) data + 48;
53 if (memcmp("\ntype ", type_line-1, 6))
54 return -1;
55
56 tag_line = strchr(type_line, '\n');
57 if (!tag_line || memcmp("tag ", ++tag_line, 4))
58 return -1;
59
60 sig_line = strchr(tag_line, '\n');
61 if (!sig_line)
62 return -1;
63 sig_line++;
64
65 typelen = tag_line - type_line - strlen("type \n");
66 if (typelen >= 20)
67 return -1;
68 memcpy(type, type_line + 5, typelen);
69 type[typelen] = '\0';
70 taglen = sig_line - tag_line - strlen("tag \n");
71 item->tag = xmalloc(taglen + 1);
72 memcpy(item->tag, tag_line + 4, taglen);
73 item->tag[taglen] = '\0';
74
75 if (!strcmp(type, blob_type)) {
76 item->tagged = &lookup_blob(sha1)->object;
77 } else if (!strcmp(type, tree_type)) {
78 item->tagged = &lookup_tree(sha1)->object;
79 } else if (!strcmp(type, commit_type)) {
80 item->tagged = &lookup_commit(sha1)->object;
81 } else if (!strcmp(type, tag_type)) {
82 item->tagged = &lookup_tag(sha1)->object;
83 } else {
84 error("Unknown type %s", type);
85 item->tagged = NULL;
86 }
87
88 if (item->tagged && track_object_refs) {
89 struct object_refs *refs = alloc_object_refs(1);
90 refs->ref[0] = item->tagged;
91 set_object_refs(&item->object, refs);
92 }
93
94 return 0;
95 }
96
97 int parse_tag(struct tag *item)
98 {
99 enum object_type type;
100 void *data;
101 unsigned long size;
102 int ret;
103
104 if (item->object.parsed)
105 return 0;
106 data = read_sha1_file(item->object.sha1, &type, &size);
107 if (!data)
108 return error("Could not read %s",
109 sha1_to_hex(item->object.sha1));
110 if (type != OBJ_TAG) {
111 free(data);
112 return error("Object %s not a tag",
113 sha1_to_hex(item->object.sha1));
114 }
115 ret = parse_tag_buffer(item, data, size);
116 free(data);
117 return ret;
118 }