| 'use strict' |
| |
| // Node has always utf-8 |
| const utf8Decoder = new TextDecoder('utf-8') |
| const textDecoders = new Map([ |
| ['utf-8', utf8Decoder], |
| ['utf8', utf8Decoder] |
| ]) |
| |
| function getDecoder (charset) { |
| let lc |
| while (true) { |
| switch (charset) { |
| case 'utf-8': |
| case 'utf8': |
| return decoders.utf8 |
| case 'latin1': |
| case 'ascii': // TODO: Make these a separate, strict decoder? |
| case 'us-ascii': |
| case 'iso-8859-1': |
| case 'iso8859-1': |
| case 'iso88591': |
| case 'iso_8859-1': |
| case 'windows-1252': |
| case 'iso_8859-1:1987': |
| case 'cp1252': |
| case 'x-cp1252': |
| return decoders.latin1 |
| case 'utf16le': |
| case 'utf-16le': |
| case 'ucs2': |
| case 'ucs-2': |
| return decoders.utf16le |
| case 'base64': |
| return decoders.base64 |
| default: |
| if (lc === undefined) { |
| lc = true |
| charset = charset.toLowerCase() |
| continue |
| } |
| return decoders.other.bind(charset) |
| } |
| } |
| } |
| |
| const decoders = { |
| utf8: (data, sourceEncoding) => { |
| if (data.length === 0) { |
| return '' |
| } |
| if (typeof data === 'string') { |
| data = Buffer.from(data, sourceEncoding) |
| } |
| return data.utf8Slice(0, data.length) |
| }, |
| |
| latin1: (data, sourceEncoding) => { |
| if (data.length === 0) { |
| return '' |
| } |
| if (typeof data === 'string') { |
| return data |
| } |
| return data.latin1Slice(0, data.length) |
| }, |
| |
| utf16le: (data, sourceEncoding) => { |
| if (data.length === 0) { |
| return '' |
| } |
| if (typeof data === 'string') { |
| data = Buffer.from(data, sourceEncoding) |
| } |
| return data.ucs2Slice(0, data.length) |
| }, |
| |
| base64: (data, sourceEncoding) => { |
| if (data.length === 0) { |
| return '' |
| } |
| if (typeof data === 'string') { |
| data = Buffer.from(data, sourceEncoding) |
| } |
| return data.base64Slice(0, data.length) |
| }, |
| |
| other: (data, sourceEncoding) => { |
| if (data.length === 0) { |
| return '' |
| } |
| if (typeof data === 'string') { |
| data = Buffer.from(data, sourceEncoding) |
| } |
| |
| if (textDecoders.has(this.toString())) { |
| try { |
| return textDecoders.get(this).decode(data) |
| } catch (e) { } |
| } |
| return typeof data === 'string' |
| ? data |
| : data.toString() |
| } |
| } |
| |
| function decodeText (text, sourceEncoding, destEncoding) { |
| if (text) { |
| return getDecoder(destEncoding)(text, sourceEncoding) |
| } |
| return text |
| } |
| |
| module.exports = decodeText |
