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
|
// not used
/* eslint-disable no-underscore-dangle */
'use strict';
const { Transform } = require('stream');
const errors = require('../FormidableError.js');
const { FormidableError } = errors;
const AMPERSAND = 38;
const EQUALS = 61;
class QuerystringParser extends Transform {
constructor(options = {}) {
super({ readableObjectMode: true });
const { maxFieldSize } = options;
this.maxFieldLength = maxFieldSize;
this.buffer = Buffer.from('');
this.fieldCount = 0;
this.sectionStart = 0;
this.key = '';
this.readingKey = true;
}
_transform(buffer, encoding, callback) {
let len = buffer.length;
if (this.buffer && this.buffer.length) {
// we have some data left over from the last write which we are in the middle of processing
len += this.buffer.length;
buffer = Buffer.concat([this.buffer, buffer], len);
}
for (let i = this.buffer.length || 0; i < len; i += 1) {
const c = buffer[i];
if (this.readingKey) {
// KEY, check for =
if (c === EQUALS) {
this.key = this.getSection(buffer, i);
this.readingKey = false;
this.sectionStart = i + 1;
} else if (c === AMPERSAND) {
// just key, no value. Prepare to read another key
this.emitField(this.getSection(buffer, i));
this.sectionStart = i + 1;
}
// VALUE, check for &
} else if (c === AMPERSAND) {
this.emitField(this.key, this.getSection(buffer, i));
this.sectionStart = i + 1;
}
if (
this.maxFieldLength &&
i - this.sectionStart === this.maxFieldLength
) {
callback(
new FormidableError(
`${
this.readingKey ? 'Key' : `Value for ${this.key}`
} longer than maxFieldLength`,
),
errors.maxFieldsSizeExceeded,
413,
);
}
}
// Prepare the remaining key or value (from sectionStart to the end) for the next write() or for end()
len -= this.sectionStart;
if (len) {
// i.e. Unless the last character was a & or =
this.buffer = Buffer.from(this.buffer, 0, this.sectionStart);
} else this.buffer = null;
this.sectionStart = 0;
callback();
}
_flush(callback) {
// Emit the last field
if (this.readingKey) {
// we only have a key if there's something in the buffer. We definitely have no value
if (this.buffer && this.buffer.length){
this.emitField(this.buffer.toString('ascii'));
}
} else {
// We have a key, we may or may not have a value
this.emitField(
this.key,
this.buffer && this.buffer.length && this.buffer.toString('ascii'),
);
}
this.buffer = '';
callback();
}
getSection(buffer, i) {
if (i === this.sectionStart) return '';
return buffer.toString('ascii', this.sectionStart, i);
}
emitField(key, val) {
this.key = '';
this.readingKey = true;
this.push({ key, value: val || '' });
}
}
module.exports = QuerystringParser;
// const q = new QuerystringParser({maxFieldSize: 100});
// (async function() {
// for await (const chunk of q) {
// console.log(chunk);
// }
// })();
// q.write("a=b&c=d")
// q.end()
|
