nodejs
diff --git a/‎lib/internal/encoding.js‎
Lines changed: 49 additions & 42 deletions b/‎lib/internal/encoding.js‎
Lines changed: 49 additions & 42 deletions
diff --git a/‎lib/internal/encoding/single-byte.js‎
Lines changed: 155 additions & 0 deletions b/‎lib/internal/encoding/single-byte.js‎
Lines changed: 155 additions & 0 deletions
@@ -13,25 +13,28 @@ const {
   StringPrototypeSlice,
   Symbol,
   SymbolToStringTag,
-  Uint8Array,
 } = primordials;
 
+const { FastBuffer } = require('internal/buffer');
+
 const {
   ERR_ENCODING_NOT_SUPPORTED,
   ERR_INVALID_ARG_TYPE,
   ERR_INVALID_THIS,
   ERR_NO_ICU,
 } = require('internal/errors').codes;
+const kMethod = Symbol('method');
 const kHandle = Symbol('handle');
 const kFlags = Symbol('flags');
 const kEncoding = Symbol('encoding');
 const kDecoder = Symbol('decoder');
 const kEncoder = Symbol('encoder');
 const kFatal = Symbol('kFatal');
 const kUTF8FastPath = Symbol('kUTF8FastPath');
-const kWindows1252FastPath = Symbol('kWindows1252FastPath');
 const kIgnoreBOM = Symbol('kIgnoreBOM');
 
+const { isSinglebyteEncoding, createSinglebyteDecoder } = require('internal/encoding/single-byte');
+
 const {
   getConstructorOf,
   customInspectSymbol: inspect,
@@ -56,11 +59,8 @@ const {
   encodeIntoResults,
   encodeUtf8String,
   decodeUTF8,
-  decodeWindows1252,
 } = binding;
 
-const { Buffer } = require('buffer');
-
 function validateEncoder(obj) {
   if (obj == null || obj[kEncoder] !== true)
     throw new ERR_INVALID_THIS('TextEncoder');
@@ -75,7 +75,7 @@ const CONVERTER_FLAGS_FLUSH = 0x1;
 const CONVERTER_FLAGS_FATAL = 0x2;
 const CONVERTER_FLAGS_IGNORE_BOM = 0x4;
 
-const empty = new Uint8Array(0);
+const empty = new FastBuffer();
 
 const encodings = new SafeMap([
   ['unicode-1-1-utf-8', 'utf-8'],
@@ -388,6 +388,24 @@ ObjectDefineProperties(
     [SymbolToStringTag]: { __proto__: null, configurable: true, value: 'TextEncoder' },
   });
 
+function parseInput(input) {
+  if (isAnyArrayBuffer(input)) {
+    try {
+      return new FastBuffer(input);
+    } catch {
+      return empty;
+    }
+  } else if (isArrayBufferView(input)) {
+    try {
+      return new FastBuffer(input.buffer, input.byteOffset, input.byteLength);
+    } catch {
+      return empty;
+    }
+  } else {
+    throw new ERR_INVALID_ARG_TYPE('input', ['ArrayBuffer', 'ArrayBufferView'], input);
+  }
+}
+
 const TextDecoder =
   internalBinding('config').hasIntl ?
     makeTextDecoderICU() :
@@ -421,10 +439,12 @@ function makeTextDecoderICU() {
       this[kFatal] = Boolean(options?.fatal);
       // Only support fast path for UTF-8.
       this[kUTF8FastPath] = enc === 'utf-8';
-      this[kWindows1252FastPath] = enc === 'windows-1252';
       this[kHandle] = undefined;
+      this[kMethod] = undefined;
 
-      if (!this[kUTF8FastPath] && !this[kWindows1252FastPath]) {
+      if (isSinglebyteEncoding(this.encoding)) {
+        this[kMethod] = createSinglebyteDecoder(this.encoding, this[kFatal]);
+      } else if (!this[kUTF8FastPath]) {
         this.#prepareConverter();
       }
     }
@@ -441,22 +461,18 @@ function makeTextDecoderICU() {
 
     decode(input = empty, options = kEmptyObject) {
       validateDecoder(this);
+      validateObject(options, 'options', kValidateObjectAllowObjectsAndNull);
+
+      if (this[kMethod]) return this[kMethod](parseInput(input));
 
       this[kUTF8FastPath] &&= !(options?.stream);
-      this[kWindows1252FastPath] &&= !(options?.stream);
 
       if (this[kUTF8FastPath]) {
         return decodeUTF8(input, this[kIgnoreBOM], this[kFatal]);
       }
 
-      if (this[kWindows1252FastPath]) {
-        return decodeWindows1252(input, this[kIgnoreBOM], this[kFatal]);
-      }
-
       this.#prepareConverter();
 
-      validateObject(options, 'options', kValidateObjectAllowObjectsAndNull);
-
       let flags = 0;
       if (options !== null)
         flags |= options.stream ? 0 : CONVERTER_FLAGS_FLUSH;
@@ -488,47 +504,40 @@ function makeTextDecoderJS() {
       validateObject(options, 'options', kValidateObjectAllowObjectsAndNull);
 
       const enc = getEncodingFromLabel(encoding);
-      if (enc === undefined || !hasConverter(enc))
+      if (enc === undefined)
         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.fatal ? CONVERTER_FLAGS_FATAL : 0;
         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[kIgnoreBOM] = Boolean(options?.ignoreBOM);
+      this[kFatal] = Boolean(options?.fatal);
       this[kBOMSeen] = false;
+      this[kMethod] = undefined;
+
+      if (isSinglebyteEncoding(enc)) {
+        this[kMethod] = createSinglebyteDecoder(enc, this[kFatal]);
+      } else {
+        if (!hasConverter(enc)) throw new ERR_ENCODING_NOT_SUPPORTED(encoding);
+        if (this[kFatal]) throw new ERR_NO_ICU('"fatal" option');
+        // StringDecoder will normalize WHATWG encoding to Node.js encoding.
+        this[kHandle] = new (lazyStringDecoder())(enc);
+      }
     }
 
     decode(input = empty, options = kEmptyObject) {
       validateDecoder(this);
-      if (isAnyArrayBuffer(input)) {
-        try {
-          input = Buffer.from(input);
-        } catch {
-          input = empty;
-        }
-      } else if (isArrayBufferView(input)) {
-        try {
-          input = Buffer.from(input.buffer, input.byteOffset,
-                              input.byteLength);
-        } catch {
-          input = empty;
-        }
-      } else {
-        throw new ERR_INVALID_ARG_TYPE('input',
-                                       ['ArrayBuffer', 'ArrayBufferView'],
-                                       input);
-      }
+      input = parseInput(input);
       validateObject(options, 'options', kValidateObjectAllowObjectsAndNull);
 
+      if (this[kMethod]) return this[kMethod](input);
+
       if (this[kFlags] & CONVERTER_FLAGS_FLUSH) {
         this[kBOMSeen] = false;
       }
@@ -543,9 +552,7 @@ function makeTextDecoderJS() {
         this[kHandle].end(input) :
         this[kHandle].write(input);
 
-      if (result.length > 0 &&
-          !this[kBOMSeen] &&
-          !(this[kFlags] & CONVERTER_FLAGS_IGNORE_BOM)) {
+      if (result.length > 0 && !this[kBOMSeen] && !this[kIgnoreBOM]) {
         // 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') {
 
@@ -0,0 +1,155 @@
+// Simplified version extracted from https://npmjs.com/package/@exodus/bytes codepath for 1-byte encodings
+// Copyright Exodus Movement. Licensed under MIT License.
+
+'use strict';
+
+const {
+  Array,
+  ArrayPrototypeFill,
+  ObjectKeys,
+  ObjectPrototypeHasOwnProperty,
+  SafeArrayIterator,
+  SafeMap,
+  SafeSet,
+  StringPrototypeIncludes,
+  TypedArrayFrom,
+  TypedArrayOf,
+  TypedArrayPrototypeIncludes,
+  TypedArrayPrototypeSet,
+  Uint16Array,
+} = primordials;
+
+const { isAscii } = require('buffer');
+
+const { FastBuffer } = require('internal/buffer');
+
+const {
+  ERR_ENCODING_NOT_SUPPORTED,
+  ERR_ENCODING_INVALID_ENCODED_DATA,
+} = require('internal/errors').codes;
+
+const isBigEndian = new FastBuffer(TypedArrayOf(Uint16Array, 258).buffer)[1] === 2;
+
+const it = (x) => new SafeArrayIterator(x);
+
+/* fallback/single-byte.encodings.js */
+
+const r = 0xfffd;
+const e = (x) => it(ArrayPrototypeFill(new Array(x), 1));
+const h = (x) => it(ArrayPrototypeFill(new Array(x), r));
+
+/* eslint-disable @stylistic/js/max-len */
+
+// Index tables from https://encoding.spec.whatwg.org/#legacy-single-byte-encodings
+// Each table in the spec lists only mapping from byte 0x80 onwards, as below that they are all ASCII and mapped as idenity
+// Here, 0xfffd (replacement charcode) designates a hole (unmapped offset), as not all encodings map all offsets
+// All other numbers are deltas from the last seen mapped value, starting with 0x7f (127, highest ASCII)
+// Thus, [0x80, 0x81, , 0x83] is stored as [1, 1, r, 2]
+// Truncation (length < 128) means that all remaining ones are mapped as identity (offset i => codepoint i), not unmapped
+const encodings = {
+  '__proto__': null,
+  'ibm866': [913, ...e(47), 8530, 1, 1, -145, 34, 61, 1, -12, -1, 14, -18, 6, 6, -1, -1, -75, 4, 32, -8, -16, -28, 60, 34, 1, -5, -6, 21, -3, -6, -16, 28, -5, 1, -4, 1, -12, -1, -6, 1, 24, -1, -82, -12, 124, -4, 8, 4, -16, -8512, ...e(15), -78, 80, -77, 80, -77, 80, -73, 80, -942, 8553, -8546, 8547, -260, -8306, 9468, -9472],
+  'iso-8859-10': [...e(33), 100, 14, 16, 8, -2, 14, -143, 148, -43, 80, 6, 23, -208, 189, -32, -154, 85, 14, 16, 8, -2, 14, -128, 133, -43, 80, 6, 23, 7831, -7850, -32, -75, -63, ...e(5), 104, -34, -67, 79, -77, 75, -73, 1, 1, 1, 117, 7, -121, 1, 1, 1, 146, -144, 154, -152, ...e(5), 34, -32, ...e(5), 73, -34, -36, 48, -46, 44, -42, 1, 1, 1, 86, 7, -90, 1, 1, 1, 115, -113, 123, -121, 1, 1, 1, 1, 58],
+  'iso-8859-13': [...e(33), 8061, -8059, 1, 1, 8058, -8056, 1, 49, -47, 173, -171, 1, 1, 1, 24, -22, 1, 1, 1, 8041, -8039, 1, 1, 65, -63, 158, -156, 1, 1, 1, 40, 30, 42, -46, 6, -66, 1, 83, -6, -6, -67, 176, -99, 12, 20, -12, 17, 37, -29, 2, -114, 121, -119, 1, 1, 155, -49, 25, 16, -142, 159, 2, -158, 38, 42, -46, 6, -35, 1, 52, -6, -6, -36, 145, -99, 12, 20, -12, 17, 37, -29, 2, -83, 90, -88, 1, 1, 124, -49, 25, 16, -111, 128, 2, 7835],
+  'iso-8859-14': [...e(33), 7522, 1, -7520, 103, 1, 7423, -7523, 7641, -7639, 7641, -119, 231, -7749, 1, 202, 7334, 1, -7423, 1, 7455, 1, -7563, 7584, 43, -42, 44, -35, 147, -111, 1, -36, -7585, ...e(15), 165, -163, ...e(5), 7572, -7570, ...e(5), 153, -151, ...e(16), 134, -132, ...e(5), 7541, -7539, ...e(5), 122],
+  'iso-8859-15': [...e(33), 1, 1, 1, 8201, -8199, 187, -185, 186, -184, ...e(10), 202, -200, 1, 1, 199, -197, 1, 1, 151, 1, 37],
+  'iso-8859-16': [...e(33), 100, 1, 60, 8043, -142, -7870, -185, 186, -184, 367, -365, 206, -204, 205, 1, -203, 1, 91, 54, 59, 7840, -8039, 1, 199, -113, 268, -350, 151, 1, 37, 4, -188, 1, 1, 64, -62, 66, -64, ...e(9), 65, 51, -113, 1, 1, 124, -122, 132, 22, -151, 1, 1, 1, 60, 258, -315, 1, 1, 1, 33, -31, 35, -33, ...e(9), 34, 51, -82, 1, 1, 93, -91, 101, 22, -120, 1, 1, 1, 29, 258],
+  'iso-8859-2': [...e(33), 100, 468, -407, -157, 153, 29, -179, 1, 184, -2, 6, 21, -204, 208, -2, -203, 85, 470, -409, -142, 138, 29, 364, -527, 169, -2, 6, 21, 355, -351, -2, -40, -147, 1, 64, -62, 117, -51, -63, 69, -67, 79, -77, 79, -77, 1, 64, 2, 51, 4, -116, 1, 124, -122, 1, 129, 22, -148, 150, -148, 1, 133, -131, 118, -116, 1, 33, -31, 86, -51, -32, 38, -36, 48, -46, 48, -46, 1, 33, 2, 51, 4, -85, 1, 93, -91, 1, 98, 22, -117, 119, -117, 1, 102, 374],
+  'iso-8859-3': [...e(33), 134, 434, -565, 1, r, 128, -125, 1, 136, 46, -64, 22, -135, r, 206, -203, 119, -117, 1, 1, 1, 112, -110, 1, 121, 46, -64, 22, -120, r, 191, -188, 1, 1, r, 2, 70, -2, -65, ...e(8), r, 2, 1, 1, 1, 76, -74, 1, 69, -67, 1, 1, 1, 144, -16, -125, 1, 1, 1, r, 2, 39, -2, -34, ...e(8), r, 2, 1, 1, 1, 45, -43, 1, 38, -36, 1, 1, 1, 113, -16, 380],
+  'iso-8859-4': [...e(33), 100, 52, 30, -178, 132, 19, -148, 1, 184, -78, 16, 68, -185, 208, -206, 1, 85, 470, -388, -163, 117, 19, 395, -527, 169, -78, 16, 68, -29, 52, -51, -75, -63, ...e(5), 104, -34, -67, 79, -77, 75, -73, 1, 92, -26, 53, 7, -22, -98, 1, 1, 1, 1, 154, -152, 1, 1, 140, 2, -139, 34, -32, ...e(5), 73, -34, -36, 48, -46, 44, -42, 1, 61, -26, 53, 7, -22, -67, 1, 1, 1, 1, 123, -121, 1, 1, 109, 2, 366],
+  'iso-8859-5': [...e(33), 865, ...e(11), -863, 865, ...e(65), 7367, -7365, ...e(11), -949, 951, 1],
+  'iso-8859-6': [...e(33), r, r, r, 4, ...h(7), 1384, -1375, ...h(13), 1390, r, r, r, 4, r, 2, ...e(25), r, r, r, r, r, 6, ...e(18), ...h(13)],
+  'iso-8859-7': [...e(33), 8056, 1, -8054, 8201, 3, -8201, 1, 1, 1, 721, -719, 1, 1, r, 8040, -8037, 1, 1, 1, 721, 1, 1, -719, 721, 1, 1, -719, 721, -719, 721, ...e(19), r, 2, ...e(43), r],
+  'iso-8859-8': [...e(33), r, 2, ...e(7), 46, -44, ...e(14), 62, -60, 1, 1, 1, ...h(32), 8025, -6727, ...e(26), r, r, 6692, 1, r],
+  'koi8-r': [9345, 2, 10, 4, 4, 4, 4, 8, 8, 8, 8, 68, 4, 4, 4, 4, 1, 1, 1, -627, 640, -903, 1, 46, 28, 1, -8645, 8833, -8817, 2, 5, 64, 9305, 1, 1, -8449, 8450, ...e(14), -8544, 8545, ...e(10), -9411, 933, -30, 1, 21, -18, 1, 15, -17, 18, -13, ...e(7), 16, -15, 1, 1, 1, -13, -4, 26, -1, -20, 17, 5, -4, -2, 3, -28, -30, 1, 21, -18, 1, 15, -17, 18, -13, ...e(7), 16, -15, 1, 1, 1, -13, -4, 26, -1, -20, 17, 5, -4, -2, 3],
+  'koi8-u': [9345, 2, 10, 4, 4, 4, 4, 8, 8, 8, 8, 68, 4, 4, 4, 4, 1, 1, 1, -627, 640, -903, 1, 46, 28, 1, -8645, 8833, -8817, 2, 5, 64, 9305, 1, 1, -8449, 3, 8448, -8446, 1, 8448, 1, 1, 1, 1, -8394, -51, 8448, 1, 1, 1, -8544, 3, 8543, -8541, 1, 8543, 1, 1, 1, 1, -8410, -130, -869, 933, -30, 1, 21, -18, 1, 15, -17, 18, -13, ...e(7), 16, -15, 1, 1, 1, -13, -4, 26, -1, -20, 17, 5, -4, -2, 3, -28, -30, 1, 21, -18, 1, 15, -17, 18, -13, ...e(7), 16, -15, 1, 1, 1, -13, -4, 26, -1, -20, 17, 5, -4, -2, 3],
+  'macintosh': [69, 1, 2, 2, 8, 5, 6, 5, -1, 2, 2, -1, 2, 2, 2, -1, 2, 1, 2, -1, 2, 1, 2, 2, -1, 2, 2, -1, 5, -1, 2, 1, 7972, -8048, -14, 1, 4, 8059, -8044, 41, -49, -5, 8313, -8302, -12, 8632, -8602, 18, 8518, -8557, 8627, 1, -8640, 16, 8525, 15, -2, -7759, 7787, -8577, 16, 751, -707, 18, -57, -30, 11, 8558, -8328, 8374, -66, -8539, 16, 8043, -8070, 32, 3, 18, 125, 1, 7872, 1, 8, 1, -5, 1, -7970, 9427, -9419, 121, 7884, 104, -115, 1, 56007, 1, -56033, -8042, 8035, 4, 18, -8046, 8, -9, 10, -3, 5, 1, 1, -3, 7, 1, 63531, -63533, 8, 1, -2, 88, 405, 22, -557, 553, 1, 1, -546, 549, -2, -20],
+  'windows-1250': [8237, -8235, 8089, -8087, 8091, 8, -6, 1, -8089, 8104, -7888, 7897, -7903, 10, 25, -4, -233, 8072, 1, 3, 1, 5, -15, 1, -8060, 8330, -8129, 7897, -7903, 10, 25, -4, -218, 551, 17, -407, -157, 96, -94, 1, 1, 1, 181, -179, 1, 1, 1, 205, -203, 1, 554, -409, -142, 1, 1, 1, 1, 77, 90, -164, 130, 416, -415, 62, -40, -147, 1, 64, -62, 117, -51, -63, 69, -67, 79, -77, 79, -77, 1, 64, 2, 51, 4, -116, 1, 124, -122, 1, 129, 22, -148, 150, -148, 1, 133, -131, 118, -116, 1, 33, -31, 86, -51, -32, 38, -36, 48, -46, 48, -46, 1, 33, 2, 51, 4, -85, 1, 93, -91, 1, 98, 22, -117, 119, -117, 1, 102, 374],
+  'windows-1251': [899, 1, 7191, -7111, 7115, 8, -6, 1, 139, -124, -7207, 7216, -7215, 2, -1, 4, 67, 7110, 1, 3, 1, 5, -15, 1, -8060, 8330, -7369, 7137, -7136, 2, -1, 4, -959, 878, 80, -86, -868, 1004, -1002, 1, 858, -856, 859, -857, 1, 1, 1, 857, -855, 1, 853, 80, 59, -988, 1, 1, 922, 7365, -7362, -921, 925, -83, 80, 2, -71, ...e(63)],
+  'windows-1252': [8237, -8235, 8089, -7816, 7820, 8, -6, 1, -7515, 7530, -7888, 7897, -7911, -197, 240, -238, 1, 8072, 1, 3, 1, 5, -15, 1, -7480, 7750, -8129, 7897, -7911, -182, 225, -6],
+  'windows-1253': [8237, -8235, 8089, -7816, 7820, 8, -6, 1, -8089, 8104, -8102, 8111, -8109, 1, 1, 1, 1, 8072, 1, 3, 1, 5, -15, 1, -8060, 8330, -8328, 8096, -8094, 1, 1, 1, 1, 741, 1, -739, 1, 1, 1, 1, 1, 1, r, 2, 1, 1, 1, 8039, -8037, 1, 1, 1, 721, -719, 1, 1, 721, 1, 1, -719, 721, -719, 721, ...e(19), r, 2, ...e(43), r],
+  'windows-1254': [8237, -8235, 8089, -7816, 7820, 8, -6, 1, -7515, 7530, -7888, 7897, -7911, -197, 1, 1, 1, 8072, 1, 3, 1, 5, -15, 1, -7480, 7750, -8129, 7897, -7911, -182, 1, 218, -216, ...e(47), 79, -77, ...e(11), 84, 46, -127, ...e(16), 48, -46, ...e(11), 53, 46],
+  'windows-1255': [8237, -8235, 8089, -7816, 7820, 8, -6, 1, -7515, 7530, -8102, 8111, -8109, 1, 1, 1, 1, 8072, 1, 3, 1, 5, -15, 1, -7480, 7750, -8328, 8096, -8094, ...e(7), 8199, -8197, 1, 1, 1, 1, 46, -44, ...e(14), 62, -60, 1, 1, 1, 1, 1265, ...e(19), 45, 1, 1, 1, 1, ...h(7), -36, ...e(26), r, r, 6692, 1, r],
+  'windows-1256': [8237, -6702, 6556, -7816, 7820, 8, -6, 1, -7515, 7530, -6583, 6592, -7911, 1332, 18, -16, 39, 6505, 1, 3, 1, 5, -15, 1, -6507, 6777, -6801, 6569, -7911, 7865, 1, -6483, -1562, 1388, -1386, ...e(7), 1557, -1555, ...e(14), 1378, -1376, 1, 1, 1, 1377, 162, -160, ...e(21), -1375, 1376, 1, 1, 1, 6, 1, 1, 1, -1379, 1380, -1378, 1379, 1, 1, 1, -1377, 1, 1, 1, 1, 1374, 1, -1372, 1, 1372, 1, 1, 1, -1370, 1371, 1, -1369, 1370, -1368, 1369, -1367, 1, 7954, 1, -6461],
+  'windows-1257': [8237, -8235, 8089, -8087, 8091, 8, -6, 1, -8089, 8104, -8102, 8111, -8109, 28, 543, -527, -40, 8072, 1, 3, 1, 5, -15, 1, -8060, 8330, -8328, 8096, -8094, 19, 556, -572, 1, r, 2, 1, 1, r, 2, 1, 49, -47, 173, -171, 1, 1, 1, 24, -22, ...e(5), 1, 1, 65, -63, 158, -156, 1, 1, 1, 40, 30, 42, -46, 6, -66, 1, 83, -6, -6, -67, 176, -99, 12, 20, -12, 17, 37, -29, 2, -114, 121, -119, 1, 1, 155, -49, 25, 16, -142, 159, 2, -158, 38, 42, -46, 6, -35, 1, 52, -6, -6, -36, 145, -99, 12, 20, -12, 17, 37, -29, 2, -83, 90, -88, 1, 1, 124, -49, 25, 16, -111, 128, 2, 347],
+  'windows-1258': [8237, -8235, 8089, -7816, 7820, 8, -6, 1, -7515, 7530, -8102, 8111, -7911, -197, 1, 1, 1, 8072, 1, 3, 1, 5, -15, 1, -7480, 7750, -8328, 8096, -7911, -182, 1, 218, -216, ...e(34), 64, -62, ...e(7), 565, -563, 1, 1, 65, -63, 568, -566, 1, 204, -202, 1, 1, 1, 1, 1, 1, 211, 340, -548, 1, 1, 1, 33, -31, ...e(7), 534, -532, 1, 1, 34, -32, 562, -560, 1, 173, -171, 1, 1, 1, 1, 1, 1, 180, 7931],
+  'windows-874': [8237, -8235, 1, 1, 1, 8098, -8096, ...e(10), 8072, 1, 3, 1, 5, -15, 1, -8060, ...e(8), 3425, ...e(57), r, r, r, r, 5, ...e(28), r, r, r, r],
+  'x-mac-cyrillic': [913, ...e(31), 7153, -8048, 992, -1005, 4, 8059, -8044, 848, -856, -5, 8313, -7456, 80, 7694, -7773, 80, 7627, -8557, 8627, 1, -7695, -929, 988, -137, -4, 80, -77, 80, -78, 80, -79, 80, -2, -83, -857, 8558, -8328, 8374, -66, -8539, 16, 8043, -8070, 875, 80, -79, 80, -7, 7102, 1, 8, 1, -5, 1, -7970, 7975, -7184, 80, -79, 80, 7351, -7445, 80, -2, -31, ...e(30), 7262],
+};
+
+/* eslint-enable @stylistic/js/max-len */
+
+/* fallback/single-byte.js + single-byte.node.js, simplified */
+
+const l256 = { __proto__: null, length: 256 };
+
+function getEncoding(encoding) {
+  if (encoding === 'x-user-defined') {
+    // https://encoding.spec.whatwg.org/#x-user-defined-decoder, 14.5.1. x-user-defined decoder
+    return TypedArrayFrom(Uint16Array, l256, (_, i) => (i >= 0x80 ? 0xf700 + i : i));
+  }
+
+  if (!ObjectPrototypeHasOwnProperty(encodings, encoding)) {
+    throw new ERR_ENCODING_NOT_SUPPORTED(encoding);
+  }
+
+  const map = TypedArrayFrom(Uint16Array, l256, (_, i) => i); // Unicode subset
+  let prev = 127;
+  map.set(TypedArrayFrom(Uint16Array, it(encodings[encoding]), (x) => (x === r ? x : (prev += x))), 128);
+  return map;
+}
+
+const supported = new SafeSet(it(ObjectKeys(encodings))).add('iso-8859-8-i').add('x-user-defined');
+const isSinglebyteEncoding = (enc) => supported.has(enc);
+
+const decodersLoose = new SafeMap();
+const decodersFatal = new SafeMap();
+
+function createSinglebyteDecoder(encoding, fatal) {
+  const id = encoding === 'iso-8859-8-i' ? 'iso-8859-8' : encoding;
+  const decoders = fatal ? decodersFatal : decodersLoose;
+  const cached = decoders.get(id);
+  if (cached) return cached;
+
+  const map = getEncoding(id);
+  const incomplete = TypedArrayPrototypeIncludes(map, r);
+
+  // Expects type-checked Buffer input
+  const decoder = (buf) => {
+    if (buf.byteLength === 0) return '';
+    if (isAscii(buf)) return buf.latin1Slice(); // .latin1Slice is faster than .asciiSlice
+    const o = new Uint16Array(buf.length);
+    TypedArrayPrototypeSet(o, buf); // Copy to modify in-place, also those are 16-bit now
+
+    let i = 0;
+    for (const end7 = o.length - 7; i < end7; i += 8) {
+      o[i] = map[o[i]];
+      o[i + 1] = map[o[i + 1]];
+      o[i + 2] = map[o[i + 2]];
+      o[i + 3] = map[o[i + 3]];
+      o[i + 4] = map[o[i + 4]];
+      o[i + 5] = map[o[i + 5]];
+      o[i + 6] = map[o[i + 6]];
+      o[i + 7] = map[o[i + 7]];
+    }
+
+    for (const end = o.length; i < end; i++) o[i] = map[o[i]];
+
+    const b = new FastBuffer(o.buffer, o.byteOffset, o.byteLength);
+    if (isBigEndian) b.swap16();
+    const string = b.ucs2Slice();
+    if (fatal && incomplete && StringPrototypeIncludes(string, '\uFFFD')) {
+      throw new ERR_ENCODING_INVALID_ENCODED_DATA(encoding, undefined);
+    }
+    return string;
+  };
+
+  decoders.set(id, decoder);
+  return decoder;
+}
+
+module.exports = {
+  isSinglebyteEncoding,
+  createSinglebyteDecoder,
+  getEncoding, // for tests
+};