decoder.js
1.18 KB
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
var iconv,
inherits = require('util').inherits,
stream = require('stream');
var regex = /(?:charset|encoding)\s*=\s*['"]? *([\w\-]+)/i;
inherits(StreamDecoder, stream.Transform);
function StreamDecoder(charset) {
if (!(this instanceof StreamDecoder))
return new StreamDecoder(charset);
stream.Transform.call(this, charset);
this.charset = charset;
this.parsed_chunk = false;
}
StreamDecoder.prototype._transform = function(chunk, encoding, done) {
var res, found;
// try get charset from chunk, just once
if (this.charset == 'iso-8859-1' && !this.parsed_chunk) {
this.parsed_chunk = true;
var matches = regex.exec(chunk.toString());
if (matches) {
found = matches[1].toLowerCase();
this.charset = found == 'utf-8' ? 'utf8' : found;
}
}
try {
res = iconv.decode(chunk, this.charset);
} catch(e) { // something went wrong, just return original chunk
res = chunk;
}
this.push(res);
done();
}
module.exports = function(charset) {
try {
if (!iconv) iconv = require('iconv-lite');
} catch(e) {
/* iconv not found */
}
if (iconv)
return new StreamDecoder(charset);
else
return new stream.PassThrough;
}