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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Parse URLs (actually URIs, but that seems overly pedantic).
// TODO(rsc): Add tests.
package http
import (
"os";
"strings"
)
export var (
BadURL = os.NewError("bad url syntax")
)
func IsHex(c byte) bool {
switch {
case '0' <= c && c <= '9':
return true;
case 'a' <= c && c <= 'f':
return true;
case 'A' <= c && c <= 'F':
return true;
}
return false
}
func UnHex(c byte) byte {
switch {
case '0' <= c && c <= '9':
return c - '0';
case 'a' <= c && c <= 'f':
return c - 'a' + 10;
case 'A' <= c && c <= 'F':
return c - 'A' + 10;
}
return 0
}
// Unescape %xx into hex.
export func URLUnescape(s string) (string, *os.Error) {
// Count %, check that they're well-formed.
n := 0;
for i := 0; i < len(s); {
if s[i] == '%' {
n++;
if !IsHex(s[i+1]) || !IsHex(s[i+2]) {
return "", BadURL;
}
i += 3
} else {
i++
}
}
if n == 0 {
return s, nil
}
t := new([]byte, len(s)-2*n);
j := 0;
for i := 0; i < len(s); {
if s[i] == '%' {
t[j] = UnHex(s[i+1]) << 4 | UnHex(s[i+2]);
j++;
i += 3;
} else {
t[j] = s[i];
j++;
i++;
}
}
return string(t), nil;
}
export type URL struct {
raw string;
scheme string;
rawpath string;
authority string;
userinfo string;
host string;
path string;
query string;
fragment string;
}
// Maybe rawurl is of the form scheme:path.
// (Scheme must be [a-zA-Z][a-zA-Z0-9+-.]*)
// If so, return scheme, path; else return "", rawurl.
func GetScheme(rawurl string) (scheme, path string, err *os.Error) {
for i := 0; i < len(rawurl); i++ {
c := rawurl[i];
switch {
case 'a' <= c && c <= 'z' ||'A' <= c && c <= 'Z':
// do nothing
case '0' <= c && c <= '9' || c == '+' || c == '-' || c == '.':
if i == 0 {
return "", rawurl, nil
}
case c == ':':
if i == 0 {
return "", "", BadURL
}
return rawurl[0:i], rawurl[i+1:len(rawurl)], nil
}
}
return "", rawurl, nil
}
// Maybe s is of the form t c u.
// If so, return t, c u (or t, u if cutc == true).
// If not, return s, "".
func Split(s string, c byte, cutc bool) (string, string) {
for i := 0; i < len(s); i++ {
if s[i] == c {
if cutc {
return s[0:i], s[i+1:len(s)]
}
return s[0:i], s[i:len(s)]
}
}
return s, ""
}
// Parse rawurl into a URL structure.
export func ParseURL(rawurl string) (url *URL, err *os.Error) {
if rawurl == "" {
return nil, BadURL
}
url = new(*URL);
url.raw = rawurl;
// Split off possible leading "http:", "mailto:", etc.
var path string;
if url.scheme, path, err = GetScheme(rawurl); err != nil {
return nil, err
}
url.rawpath = path;
// RFC 2396: a relative URI (no scheme) has a ?query,
// but absolute URIs only have query if path begins with /
if url.scheme == "" || len(path) > 0 && path[0] == '/' {
path, url.query = Split(path, '?', true);
if url.query, err = URLUnescape(url.query); err != nil {
return nil, err
}
}
// Maybe path is //authority/path
if len(path) > 2 && path[0:2] == "//" {
url.authority, path = Split(path[2:len(path)], '/', false);
}
// If there's no @, Split's default is wrong. Check explicitly.
if strings.index(url.authority, "@") < 0 {
url.host = url.authority;
} else {
url.userinfo, url.host = Split(url.authority, '@', true);
}
// What's left is the path.
// TODO: Canonicalize (remove . and ..)?
if url.path, err = URLUnescape(path); err != nil {
return nil, err
}
return url, nil
}
// A URL reference is a URL with #frag potentially added. Parse it.
export func ParseURLReference(rawurlref string) (url *URL, err *os.Error) {
// Cut off #frag.
rawurl, frag := Split(rawurlref, '#', true);
if url, err = ParseURL(rawurl); err != nil {
return nil, err
}
if url.fragment, err = URLUnescape(frag); err != nil {
return nil, err
}
return url, nil
}
|
