summaryrefslogtreecommitdiff
path: root/tag.c
blob: 85607c219e25d63b0d1f3344649104c60f5b96e2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
#include "cache.h"
#include "tag.h"
#include "commit.h"
#include "tree.h"
#include "blob.h"

const char *tag_type = "tag";

struct object *deref_tag(struct object *o, const char *warn, int warnlen)
{
	while (o && o->type == OBJ_TAG)
		if (((struct tag *)o)->tagged)
			o = parse_object(((struct tag *)o)->tagged->sha1);
		else
			o = NULL;
	if (!o && warn) {
		if (!warnlen)
			warnlen = strlen(warn);
		error("missing object referenced by '%.*s'", warnlen, warn);
	}
	return o;
}

struct tag *lookup_tag(const unsigned char *sha1)
{
	struct object *obj = lookup_object(sha1);
	if (!obj)
		return create_object(sha1, OBJ_TAG, alloc_tag_node());
	if (!obj->type)
		obj->type = OBJ_TAG;
        if (obj->type != OBJ_TAG) {
                error("Object %s is a %s, not a tag",
                      sha1_to_hex(sha1), typename(obj->type));
                return NULL;
        }
        return (struct tag *) obj;
}

static unsigned long parse_tag_date(const char *buf, const char *tail)
{
	const char *dateptr;

	while (buf < tail && *buf++ != '>')
		/* nada */;
	if (buf >= tail)
		return 0;
	dateptr = buf;
	while (buf < tail && *buf++ != '\n')
		/* nada */;
	if (buf >= tail)
		return 0;
	/* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
	return strtoul(dateptr, NULL, 10);
}

int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
{
	unsigned char sha1[20];
	char type[20];
	const char *bufptr = data;
	const char *tail = bufptr + size;
	const char *nl;

	if (item->object.parsed)
		return 0;
	item->object.parsed = 1;

	if (size < 64)
		return -1;
	if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
		return -1;
	bufptr += 48; /* "object " + sha1 + "\n" */

	if (prefixcmp(bufptr, "type "))
		return -1;
	bufptr += 5;
	nl = memchr(bufptr, '\n', tail - bufptr);
	if (!nl || sizeof(type) <= (nl - bufptr))
		return -1;
	strncpy(type, bufptr, nl - bufptr);
	type[nl - bufptr] = '\0';
	bufptr = nl + 1;

	if (!strcmp(type, blob_type)) {
		item->tagged = &lookup_blob(sha1)->object;
	} else if (!strcmp(type, tree_type)) {
		item->tagged = &lookup_tree(sha1)->object;
	} else if (!strcmp(type, commit_type)) {
		item->tagged = &lookup_commit(sha1)->object;
	} else if (!strcmp(type, tag_type)) {
		item->tagged = &lookup_tag(sha1)->object;
	} else {
		error("Unknown type %s", type);
		item->tagged = NULL;
	}

	if (prefixcmp(bufptr, "tag "))
		return -1;
	bufptr += 4;
	nl = memchr(bufptr, '\n', tail - bufptr);
	if (!nl)
		return -1;
	item->tag = xmemdupz(bufptr, nl - bufptr);
	bufptr = nl + 1;

	if (!prefixcmp(bufptr, "tagger "))
		item->date = parse_tag_date(bufptr, tail);
	else
		item->date = 0;

	return 0;
}

int parse_tag(struct tag *item)
{
	enum object_type type;
	void *data;
	unsigned long size;
	int ret;

	if (item->object.parsed)
		return 0;
	data = read_sha1_file(item->object.sha1, &type, &size);
	if (!data)
		return error("Could not read %s",
			     sha1_to_hex(item->object.sha1));
	if (type != OBJ_TAG) {
		free(data);
		return error("Object %s not a tag",
			     sha1_to_hex(item->object.sha1));
	}
	ret = parse_tag_buffer(item, data, size);
	free(data);
	return ret;
}