lts/lib/internal/encoding.js
'use strict';
// An implementation of the WHATWG Encoding Standard
// https://encoding.spec.whatwg.org
const {
Map,
ObjectCreate,
ObjectDefineProperties,
ObjectGetOwnPropertyDescriptors,
Symbol,
SymbolToStringTag,
} = primordials;
const {
ERR_ENCODING_INVALID_ENCODED_DATA,
ERR_ENCODING_NOT_SUPPORTED,
ERR_INVALID_ARG_TYPE,
ERR_INVALID_THIS,
ERR_NO_ICU
} = require('internal/errors').codes;
const kHandle = Symbol('handle');
const kFlags = Symbol('flags');
const kEncoding = Symbol('encoding');
const kDecoder = Symbol('decoder');
const kEncoder = Symbol('encoder');
const {
getConstructorOf,
customInspectSymbol: inspect
} = require('internal/util');
const {
isAnyArrayBuffer,
isArrayBufferView,
isUint8Array
} = require('internal/util/types');
const { validateString } = require('internal/validators');
const {
encodeInto,
encodeUtf8String
} = internalBinding('buffer');
let Buffer;
function lazyBuffer() {
if (Buffer === undefined)
Buffer = require('buffer').Buffer;
return Buffer;
}
function validateEncoder(obj) {
if (obj == null || obj[kEncoder] !== true)
throw new ERR_INVALID_THIS('TextEncoder');
}
function validateDecoder(obj) {
if (obj == null || obj[kDecoder] !== true)
throw new ERR_INVALID_THIS('TextDecoder');
}
function validateArgument(prop, expected, propName, expectedName) {
if (typeof prop !== expected)
throw new ERR_INVALID_ARG_TYPE(propName, expectedName, prop);
}
const CONVERTER_FLAGS_FLUSH = 0x1;
const CONVERTER_FLAGS_FATAL = 0x2;
const CONVERTER_FLAGS_IGNORE_BOM = 0x4;
const empty = new Uint8Array(0);
const encodings = new Map([
['unicode-1-1-utf-8', 'utf-8'],
['utf8', 'utf-8'],
['utf-8', 'utf-8'],
['866', 'ibm866'],
['cp866', 'ibm866'],
['csibm866', 'ibm866'],
['ibm866', 'ibm866'],
['csisolatin2', 'iso-8859-2'],
['iso-8859-2', 'iso-8859-2'],
['iso-ir-101', 'iso-8859-2'],
['iso8859-2', 'iso-8859-2'],
['iso88592', 'iso-8859-2'],
['iso_8859-2', 'iso-8859-2'],
['iso_8859-2:1987', 'iso-8859-2'],
['l2', 'iso-8859-2'],
['latin2', 'iso-8859-2'],
['csisolatin3', 'iso-8859-3'],
['iso-8859-3', 'iso-8859-3'],
['iso-ir-109', 'iso-8859-3'],
['iso8859-3', 'iso-8859-3'],
['iso88593', 'iso-8859-3'],
['iso_8859-3', 'iso-8859-3'],
['iso_8859-3:1988', 'iso-8859-3'],
['l3', 'iso-8859-3'],
['latin3', 'iso-8859-3'],
['csisolatin4', 'iso-8859-4'],
['iso-8859-4', 'iso-8859-4'],
['iso-ir-110', 'iso-8859-4'],
['iso8859-4', 'iso-8859-4'],
['iso88594', 'iso-8859-4'],
['iso_8859-4', 'iso-8859-4'],
['iso_8859-4:1988', 'iso-8859-4'],
['l4', 'iso-8859-4'],
['latin4', 'iso-8859-4'],
['csisolatincyrillic', 'iso-8859-5'],
['cyrillic', 'iso-8859-5'],
['iso-8859-5', 'iso-8859-5'],
['iso-ir-144', 'iso-8859-5'],
['iso8859-5', 'iso-8859-5'],
['iso88595', 'iso-8859-5'],
['iso_8859-5', 'iso-8859-5'],
['iso_8859-5:1988', 'iso-8859-5'],
['arabic', 'iso-8859-6'],
['asmo-708', 'iso-8859-6'],
['csiso88596e', 'iso-8859-6'],
['csiso88596i', 'iso-8859-6'],
['csisolatinarabic', 'iso-8859-6'],
['ecma-114', 'iso-8859-6'],
['iso-8859-6', 'iso-8859-6'],
['iso-8859-6-e', 'iso-8859-6'],
['iso-8859-6-i', 'iso-8859-6'],
['iso-ir-127', 'iso-8859-6'],
['iso8859-6', 'iso-8859-6'],
['iso88596', 'iso-8859-6'],
['iso_8859-6', 'iso-8859-6'],
['iso_8859-6:1987', 'iso-8859-6'],
['csisolatingreek', 'iso-8859-7'],
['ecma-118', 'iso-8859-7'],
['elot_928', 'iso-8859-7'],
['greek', 'iso-8859-7'],
['greek8', 'iso-8859-7'],
['iso-8859-7', 'iso-8859-7'],
['iso-ir-126', 'iso-8859-7'],
['iso8859-7', 'iso-8859-7'],
['iso88597', 'iso-8859-7'],
['iso_8859-7', 'iso-8859-7'],
['iso_8859-7:1987', 'iso-8859-7'],
['sun_eu_greek', 'iso-8859-7'],
['csiso88598e', 'iso-8859-8'],
['csisolatinhebrew', 'iso-8859-8'],
['hebrew', 'iso-8859-8'],
['iso-8859-8', 'iso-8859-8'],
['iso-8859-8-e', 'iso-8859-8'],
['iso-ir-138', 'iso-8859-8'],
['iso8859-8', 'iso-8859-8'],
['iso88598', 'iso-8859-8'],
['iso_8859-8', 'iso-8859-8'],
['iso_8859-8:1988', 'iso-8859-8'],
['visual', 'iso-8859-8'],
['csiso88598i', 'iso-8859-8-i'],
['iso-8859-8-i', 'iso-8859-8-i'],
['logical', 'iso-8859-8-i'],
['csisolatin6', 'iso-8859-10'],
['iso-8859-10', 'iso-8859-10'],
['iso-ir-157', 'iso-8859-10'],
['iso8859-10', 'iso-8859-10'],
['iso885910', 'iso-8859-10'],
['l6', 'iso-8859-10'],
['latin6', 'iso-8859-10'],
['iso-8859-13', 'iso-8859-13'],
['iso8859-13', 'iso-8859-13'],
['iso885913', 'iso-8859-13'],
['iso-8859-14', 'iso-8859-14'],
['iso8859-14', 'iso-8859-14'],
['iso885914', 'iso-8859-14'],
['csisolatin9', 'iso-8859-15'],
['iso-8859-15', 'iso-8859-15'],
['iso8859-15', 'iso-8859-15'],
['iso885915', 'iso-8859-15'],
['iso_8859-15', 'iso-8859-15'],
['l9', 'iso-8859-15'],
['cskoi8r', 'koi8-r'],
['koi', 'koi8-r'],
['koi8', 'koi8-r'],
['koi8-r', 'koi8-r'],
['koi8_r', 'koi8-r'],
['koi8-ru', 'koi8-u'],
['koi8-u', 'koi8-u'],
['csmacintosh', 'macintosh'],
['mac', 'macintosh'],
['macintosh', 'macintosh'],
['x-mac-roman', 'macintosh'],
['dos-874', 'windows-874'],
['iso-8859-11', 'windows-874'],
['iso8859-11', 'windows-874'],
['iso885911', 'windows-874'],
['tis-620', 'windows-874'],
['windows-874', 'windows-874'],
['cp1250', 'windows-1250'],
['windows-1250', 'windows-1250'],
['x-cp1250', 'windows-1250'],
['cp1251', 'windows-1251'],
['windows-1251', 'windows-1251'],
['x-cp1251', 'windows-1251'],
['ansi_x3.4-1968', 'windows-1252'],
['ascii', 'windows-1252'],
['cp1252', 'windows-1252'],
['cp819', 'windows-1252'],
['csisolatin1', 'windows-1252'],
['ibm819', 'windows-1252'],
['iso-8859-1', 'windows-1252'],
['iso-ir-100', 'windows-1252'],
['iso8859-1', 'windows-1252'],
['iso88591', 'windows-1252'],
['iso_8859-1', 'windows-1252'],
['iso_8859-1:1987', 'windows-1252'],
['l1', 'windows-1252'],
['latin1', 'windows-1252'],
['us-ascii', 'windows-1252'],
['windows-1252', 'windows-1252'],
['x-cp1252', 'windows-1252'],
['cp1253', 'windows-1253'],
['windows-1253', 'windows-1253'],
['x-cp1253', 'windows-1253'],
['cp1254', 'windows-1254'],
['csisolatin5', 'windows-1254'],
['iso-8859-9', 'windows-1254'],
['iso-ir-148', 'windows-1254'],
['iso8859-9', 'windows-1254'],
['iso88599', 'windows-1254'],
['iso_8859-9', 'windows-1254'],
['iso_8859-9:1989', 'windows-1254'],
['l5', 'windows-1254'],
['latin5', 'windows-1254'],
['windows-1254', 'windows-1254'],
['x-cp1254', 'windows-1254'],
['cp1255', 'windows-1255'],
['windows-1255', 'windows-1255'],
['x-cp1255', 'windows-1255'],
['cp1256', 'windows-1256'],
['windows-1256', 'windows-1256'],
['x-cp1256', 'windows-1256'],
['cp1257', 'windows-1257'],
['windows-1257', 'windows-1257'],
['x-cp1257', 'windows-1257'],
['cp1258', 'windows-1258'],
['windows-1258', 'windows-1258'],
['x-cp1258', 'windows-1258'],
['x-mac-cyrillic', 'x-mac-cyrillic'],
['x-mac-ukrainian', 'x-mac-cyrillic'],
['chinese', 'gbk'],
['csgb2312', 'gbk'],
['csiso58gb231280', 'gbk'],
['gb2312', 'gbk'],
['gb_2312', 'gbk'],
['gb_2312-80', 'gbk'],
['gbk', 'gbk'],
['iso-ir-58', 'gbk'],
['x-gbk', 'gbk'],
['gb18030', 'gb18030'],
['big5', 'big5'],
['big5-hkscs', 'big5'],
['cn-big5', 'big5'],
['csbig5', 'big5'],
['x-x-big5', 'big5'],
['cseucpkdfmtjapanese', 'euc-jp'],
['euc-jp', 'euc-jp'],
['x-euc-jp', 'euc-jp'],
['csiso2022jp', 'iso-2022-jp'],
['iso-2022-jp', 'iso-2022-jp'],
['csshiftjis', 'shift_jis'],
['ms932', 'shift_jis'],
['ms_kanji', 'shift_jis'],
['shift-jis', 'shift_jis'],
['shift_jis', 'shift_jis'],
['sjis', 'shift_jis'],
['windows-31j', 'shift_jis'],
['x-sjis', 'shift_jis'],
['cseuckr', 'euc-kr'],
['csksc56011987', 'euc-kr'],
['euc-kr', 'euc-kr'],
['iso-ir-149', 'euc-kr'],
['korean', 'euc-kr'],
['ks_c_5601-1987', 'euc-kr'],
['ks_c_5601-1989', 'euc-kr'],
['ksc5601', 'euc-kr'],
['ksc_5601', 'euc-kr'],
['windows-949', 'euc-kr'],
['utf-16be', 'utf-16be'],
['utf-16le', 'utf-16le'],
['utf-16', 'utf-16le']
]);
// Unfortunately, String.prototype.trim also removes non-ascii whitespace,
// so we have to do this manually
function trimAsciiWhitespace(label) {
let s = 0;
let e = label.length;
while (s < e && (
label[s] === '\u0009' ||
label[s] === '\u000a' ||
label[s] === '\u000c' ||
label[s] === '\u000d' ||
label[s] === '\u0020')) {
s++;
}
while (e > s && (
label[e - 1] === '\u0009' ||
label[e - 1] === '\u000a' ||
label[e - 1] === '\u000c' ||
label[e - 1] === '\u000d' ||
label[e - 1] === '\u0020')) {
e--;
}
return label.slice(s, e);
}
function getEncodingFromLabel(label) {
const enc = encodings.get(label);
if (enc !== undefined) return enc;
return encodings.get(trimAsciiWhitespace(label.toLowerCase()));
}
const encodeIntoResults = new Uint32Array(2);
class TextEncoder {
constructor() {
this[kEncoder] = true;
}
get encoding() {
validateEncoder(this);
return 'utf-8';
}
encode(input = '') {
validateEncoder(this);
return encodeUtf8String(`${input}`);
}
encodeInto(src, dest) {
validateEncoder(this);
validateString(src, 'src');
if (!dest || !isUint8Array(dest))
throw new ERR_INVALID_ARG_TYPE('dest', 'Uint8Array', dest);
encodeInto(src, dest, encodeIntoResults);
return { read: encodeIntoResults[0], written: encodeIntoResults[1] };
}
[inspect](depth, opts) {
validateEncoder(this);
if (typeof depth === 'number' && depth < 0)
return this;
const ctor = getConstructorOf(this);
const obj = ObjectCreate({
constructor: ctor === null ? TextEncoder : ctor
});
obj.encoding = this.encoding;
// Lazy to avoid circular dependency
return require('internal/util/inspect').inspect(obj, opts);
}
}
ObjectDefineProperties(
TextEncoder.prototype, {
'encode': { enumerable: true },
'encodeInto': { enumerable: true },
'encoding': { enumerable: true },
[SymbolToStringTag]: {
configurable: true,
value: 'TextEncoder'
} });
const TextDecoder =
internalBinding('config').hasIntl ?
makeTextDecoderICU() :
makeTextDecoderJS();
function makeTextDecoderICU() {
const {
decode: _decode,
getConverter,
} = internalBinding('icu');
class TextDecoder {
constructor(encoding = 'utf-8', options = {}) {
encoding = `${encoding}`;
validateArgument(options, 'object', 'options', 'Object');
const enc = getEncodingFromLabel(encoding);
if (enc === undefined)
throw new ERR_ENCODING_NOT_SUPPORTED(encoding);
let flags = 0;
if (options !== null) {
flags |= options.fatal ? CONVERTER_FLAGS_FATAL : 0;
flags |= options.ignoreBOM ? CONVERTER_FLAGS_IGNORE_BOM : 0;
}
const handle = getConverter(enc, flags);
if (handle === undefined)
throw new ERR_ENCODING_NOT_SUPPORTED(encoding);
this[kDecoder] = true;
this[kHandle] = handle;
this[kFlags] = flags;
this[kEncoding] = enc;
}
decode(input = empty, options = {}) {
validateDecoder(this);
if (isAnyArrayBuffer(input)) {
input = lazyBuffer().from(input);
} else if (!isArrayBufferView(input)) {
throw new ERR_INVALID_ARG_TYPE('input',
['ArrayBuffer', 'ArrayBufferView'],
input);
}
validateArgument(options, 'object', 'options', 'Object');
let flags = 0;
if (options !== null)
flags |= options.stream ? 0 : CONVERTER_FLAGS_FLUSH;
const ret = _decode(this[kHandle], input, flags);
if (typeof ret === 'number') {
throw new ERR_ENCODING_INVALID_ENCODED_DATA(this.encoding, ret);
}
return ret.toString('ucs2');
}
}
return TextDecoder;
}
function makeTextDecoderJS() {
let StringDecoder;
function lazyStringDecoder() {
if (StringDecoder === undefined)
({ StringDecoder } = require('string_decoder'));
return StringDecoder;
}
const kBOMSeen = Symbol('BOM seen');
function hasConverter(encoding) {
return encoding === 'utf-8' || encoding === 'utf-16le';
}
class TextDecoder {
constructor(encoding = 'utf-8', options = {}) {
encoding = `${encoding}`;
validateArgument(options, 'object', 'options', 'Object');
const enc = getEncodingFromLabel(encoding);
if (enc === undefined || !hasConverter(enc))
throw new ERR_ENCODING_NOT_SUPPORTED(encoding);
let flags = 0;
if (options !== null) {
if (options.fatal) {
throw new ERR_NO_ICU('"fatal" option');
}
flags |= options.ignoreBOM ? CONVERTER_FLAGS_IGNORE_BOM : 0;
}
this[kDecoder] = true;
// StringDecoder will normalize WHATWG encoding to Node.js encoding.
this[kHandle] = new (lazyStringDecoder())(enc);
this[kFlags] = flags;
this[kEncoding] = enc;
this[kBOMSeen] = false;
}
decode(input = empty, options = {}) {
validateDecoder(this);
if (isAnyArrayBuffer(input)) {
input = lazyBuffer().from(input);
} else if (isArrayBufferView(input)) {
input = lazyBuffer().from(input.buffer, input.byteOffset,
input.byteLength);
} else {
throw new ERR_INVALID_ARG_TYPE('input',
['ArrayBuffer', 'ArrayBufferView'],
input);
}
validateArgument(options, 'object', 'options', 'Object');
if (this[kFlags] & CONVERTER_FLAGS_FLUSH) {
this[kBOMSeen] = false;
}
if (options !== null && options.stream) {
this[kFlags] &= ~CONVERTER_FLAGS_FLUSH;
} else {
this[kFlags] |= CONVERTER_FLAGS_FLUSH;
}
let result = this[kFlags] & CONVERTER_FLAGS_FLUSH ?
this[kHandle].end(input) :
this[kHandle].write(input);
if (result.length > 0 &&
!this[kBOMSeen] &&
!(this[kFlags] & CONVERTER_FLAGS_IGNORE_BOM)) {
// If the very first result in the stream is a BOM, and we are not
// explicitly told to ignore it, then we discard it.
if (result[0] === '\ufeff') {
result = result.slice(1);
}
this[kBOMSeen] = true;
}
return result;
}
}
return TextDecoder;
}
// Mix in some shared properties.
{
ObjectDefineProperties(
TextDecoder.prototype,
ObjectGetOwnPropertyDescriptors({
get encoding() {
validateDecoder(this);
return this[kEncoding];
},
get fatal() {
validateDecoder(this);
return (this[kFlags] & CONVERTER_FLAGS_FATAL) === CONVERTER_FLAGS_FATAL;
},
get ignoreBOM() {
validateDecoder(this);
return (this[kFlags] & CONVERTER_FLAGS_IGNORE_BOM) ===
CONVERTER_FLAGS_IGNORE_BOM;
},
[inspect](depth, opts) {
validateDecoder(this);
if (typeof depth === 'number' && depth < 0)
return this;
const ctor = getConstructorOf(this);
const obj = ObjectCreate({
constructor: ctor === null ? TextDecoder : ctor
});
obj.encoding = this.encoding;
obj.fatal = this.fatal;
obj.ignoreBOM = this.ignoreBOM;
if (opts.showHidden) {
obj[kFlags] = this[kFlags];
obj[kHandle] = this[kHandle];
}
// Lazy to avoid circular dependency
return require('internal/util/inspect').inspect(obj, opts);
}
}));
ObjectDefineProperties(TextDecoder.prototype, {
decode: { enumerable: true },
[inspect]: { enumerable: false },
[SymbolToStringTag]: {
configurable: true,
value: 'TextDecoder'
}
});
}
module.exports = {
getEncodingFromLabel,
TextDecoder,
TextEncoder
};