|
| 1 | +'use strict' |
| 2 | + |
| 3 | +const RE_PLUS = /\+/g |
| 4 | + |
| 5 | +const HEX = [ |
| 6 | + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 7 | + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 8 | + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 9 | + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, |
| 10 | + 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 11 | + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 12 | + 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 13 | + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 |
| 14 | +] |
| 15 | + |
| 16 | +function Decoder () { |
| 17 | + this.buffer = undefined |
| 18 | +} |
| 19 | +Decoder.prototype.write = function (str) { |
| 20 | + // Replace '+' with ' ' before decoding |
| 21 | + str = str.replace(RE_PLUS, ' ') |
| 22 | + let res = '' |
| 23 | + let i = 0; let p = 0; const len = str.length |
| 24 | + for (; i < len; ++i) { |
| 25 | + if (this.buffer !== undefined) { |
| 26 | + if (!HEX[str.charCodeAt(i)]) { |
| 27 | + res += '%' + this.buffer |
| 28 | + this.buffer = undefined |
| 29 | + --i // retry character |
| 30 | + } else { |
| 31 | + this.buffer += str[i] |
| 32 | + ++p |
| 33 | + if (this.buffer.length === 2) { |
| 34 | + res += String.fromCharCode(parseInt(this.buffer, 16)) |
| 35 | + this.buffer = undefined |
| 36 | + } |
| 37 | + } |
| 38 | + } else if (str[i] === '%') { |
| 39 | + if (i > p) { |
| 40 | + res += str.substring(p, i) |
| 41 | + p = i |
| 42 | + } |
| 43 | + this.buffer = '' |
| 44 | + ++p |
| 45 | + } |
| 46 | + } |
| 47 | + if (p < len && this.buffer === undefined) { res += str.substring(p) } |
| 48 | + return res |
| 49 | +} |
| 50 | +Decoder.prototype.reset = function () { |
| 51 | + this.buffer = undefined |
| 52 | +} |
| 53 | + |
| 54 | +module.exports = Decoder |
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