55 lines
1.4 KiB
JavaScript
55 lines
1.4 KiB
JavaScript
'use strict'
|
|
|
|
const RE_PLUS = /\+/g
|
|
|
|
const HEX = [
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,
|
|
0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
|
|
]
|
|
|
|
function Decoder () {
|
|
this.buffer = undefined
|
|
}
|
|
Decoder.prototype.write = function (str) {
|
|
// Replace '+' with ' ' before decoding
|
|
str = str.replace(RE_PLUS, ' ')
|
|
let res = ''
|
|
let i = 0; let p = 0; const len = str.length
|
|
for (; i < len; ++i) {
|
|
if (this.buffer !== undefined) {
|
|
if (!HEX[str.charCodeAt(i)]) {
|
|
res += '%' + this.buffer
|
|
this.buffer = undefined
|
|
--i // retry character
|
|
} else {
|
|
this.buffer += str[i]
|
|
++p
|
|
if (this.buffer.length === 2) {
|
|
res += String.fromCharCode(parseInt(this.buffer, 16))
|
|
this.buffer = undefined
|
|
}
|
|
}
|
|
} else if (str[i] === '%') {
|
|
if (i > p) {
|
|
res += str.substring(p, i)
|
|
p = i
|
|
}
|
|
this.buffer = ''
|
|
++p
|
|
}
|
|
}
|
|
if (p < len && this.buffer === undefined) { res += str.substring(p) }
|
|
return res
|
|
}
|
|
Decoder.prototype.reset = function () {
|
|
this.buffer = undefined
|
|
}
|
|
|
|
module.exports = Decoder
|