unpack.js

var decoder;
try {
	decoder = new TextDecoder();
} catch(error) {}
var src;
var srcEnd;
var position = 0;
var alreadySet;
const EMPTY_ARRAY = [];
var strings = EMPTY_ARRAY;
var stringPosition = 0;
var currentUnpackr = {};
var currentStructures;
var srcString;
var srcStringStart = 0;
var srcStringEnd = 0;
var bundledStrings;
var referenceMap;
var currentExtensions = [];
var dataView;
var defaultOptions = {
	useRecords: false,
	mapsAsObjects: true
};
export class C1Type {}
export const C1 = new C1Type();
C1.name = 'MessagePack 0xC1';
var sequentialMode = false;
var inlineObjectReadThreshold = 2;
var BlockedFunction; // we use search and replace to change the next call to BlockedFunction to avoid CSP issues for

export class Unpackr {
	constructor(options) {
		if (options) {
			if (options.useRecords === false && options.mapsAsObjects === undefined)
				options.mapsAsObjects = true;
			if (options.sequential && options.trusted !== false) {
				options.trusted = true;
				if (!options.structures && options.useRecords != false) {
					options.structures = [];
					if (!options.maxSharedStructures)
						options.maxSharedStructures = 0;
				}
			}
			if (options.structures)
				options.structures.sharedLength = options.structures.length;
			else if (options.getStructures) {
				(options.structures = []).uninitialized = true; // this is what we use to denote an uninitialized structures
				options.structures.sharedLength = 0;
			}
			if (options.int64AsNumber) {
				options.int64AsType = 'number';
			}
		}
		Object.assign(this, options);
	}
	unpack(source, options) {
		if (src) {
			// re-entrant execution, save the state and restore it after we do this unpack
			return saveState(() => {
				clearSource();
				return this ? this.unpack(source, options) : Unpackr.prototype.unpack.call(defaultOptions, source, options);
			});
		}
		if (!source.buffer && source.constructor === ArrayBuffer)
			source = typeof Buffer !== 'undefined' ? Buffer.from(source) : new Uint8Array(source);
		if (typeof options === 'object') {
			srcEnd = options.end || source.length;
			position = options.start || 0;
		} else {
			position = 0;
			srcEnd = options > -1 ? options : source.length;
		}
		stringPosition = 0;
		srcStringEnd = 0;
		srcString = null;
		strings = EMPTY_ARRAY;
		bundledStrings = null;
		src = source;
		// this provides cached access to the data view for a buffer if it is getting reused, which is a recommend
		// technique for getting data from a database where it can be copied into an existing buffer instead of creating
		// new ones
		try {
			dataView = source.dataView || (source.dataView = new DataView(source.buffer, source.byteOffset, source.byteLength));
		} catch(error) {
			// if it doesn't have a buffer, maybe it is the wrong type of object
			src = null;
			if (source instanceof Uint8Array)
				throw error;
			throw new Error('Source must be a Uint8Array or Buffer but was a ' + ((source && typeof source == 'object') ? source.constructor.name : typeof source));
		}
		if (this instanceof Unpackr) {
			currentUnpackr = this;
			if (this.structures) {
				currentStructures = this.structures;
				return checkedRead(options);
			} else if (!currentStructures || currentStructures.length > 0) {
				currentStructures = [];
			}
		} else {
			currentUnpackr = defaultOptions;
			if (!currentStructures || currentStructures.length > 0)
				currentStructures = [];
		}
		return checkedRead(options);
	}
	unpackMultiple(source, forEach) {
		let values, lastPosition = 0;
		try {
			sequentialMode = true;
			let size = source.length;
			let value = this ? this.unpack(source, size) : defaultUnpackr.unpack(source, size);
			if (forEach) {
				if (forEach(value, lastPosition, position) === false) return;
				while(position < size) {
					lastPosition = position;
					if (forEach(checkedRead(), lastPosition, position) === false) {
						return;
					}
				}
			}
			else {
				values = [ value ];
				while(position < size) {
					lastPosition = position;
					values.push(checkedRead());
				}
				return values;
			}
		} catch(error) {
			error.lastPosition = lastPosition;
			error.values = values;
			throw error;
		} finally {
			sequentialMode = false;
			clearSource();
		}
	}
	_mergeStructures(loadedStructures, existingStructures) {
		if (this._onLoadedStructures)
			loadedStructures = this._onLoadedStructures(loadedStructures);
		loadedStructures = loadedStructures || [];
		if (Object.isFrozen(loadedStructures))
			loadedStructures = loadedStructures.map(structure => structure.slice(0));
		for (let i = 0, l = loadedStructures.length; i < l; i++) {
			let structure = loadedStructures[i];
			if (structure) {
				structure.isShared = true;
				if (i >= 32)
					structure.highByte = (i - 32) >> 5;
			}
		}
		loadedStructures.sharedLength = loadedStructures.length;
		for (let id in existingStructures || []) {
			if (id >= 0) {
				let structure = loadedStructures[id];
				let existing = existingStructures[id];
				if (existing) {
					if (structure)
						(loadedStructures.restoreStructures || (loadedStructures.restoreStructures = []))[id] = structure;
					loadedStructures[id] = existing;
				}
			}
		}
		return this.structures = loadedStructures;
	}
	decode(source, options) {
		return this.unpack(source, options);
	}
}
export function getPosition() {
	return position;
}
export function checkedRead(options) {
	try {
		if (!currentUnpackr.trusted && !sequentialMode) {
			let sharedLength = currentStructures.sharedLength || 0;
			if (sharedLength < currentStructures.length)
				currentStructures.length = sharedLength;
		}
		let result;
		if (currentUnpackr._readStruct && src[position] < 0x40 && src[position] >= 0x20) {
			result = currentUnpackr._readStruct(src, position, srcEnd);
			src = null; // dispose of this so that recursive unpack calls don't save state
			if (!(options && options.lazy) && result)
				result = result.toJSON();
			position = srcEnd;
		} else
			result = read();
		if (bundledStrings) { // bundled strings to skip past
			position = bundledStrings.postBundlePosition;
			bundledStrings = null;
		}
		if (sequentialMode)
			// we only need to restore the structures if there was an error, but if we completed a read,
			// we can clear this out and keep the structures we read
			currentStructures.restoreStructures = null;

		if (position == srcEnd) {
			// finished reading this source, cleanup references
			if (currentStructures && currentStructures.restoreStructures)
				restoreStructures();
			currentStructures = null;
			src = null;
			if (referenceMap)
				referenceMap = null;
		} else if (position > srcEnd) {
			// over read
			throw new Error('Unexpected end of MessagePack data');
		} else if (!sequentialMode) {
			let jsonView;
			try {
				jsonView = JSON.stringify(result, (_, value) => typeof value === "bigint" ? `${value}n` : value).slice(0, 100);
			} catch(error) {
				jsonView = '(JSON view not available ' + error + ')';
			}
			throw new Error('Data read, but end of buffer not reached ' + jsonView);
		}
		// else more to read, but we are reading sequentially, so don't clear source yet
		return result;
	} catch(error) {
		if (currentStructures && currentStructures.restoreStructures)
			restoreStructures();
		clearSource();
		if (error instanceof RangeError || error.message.startsWith('Unexpected end of buffer') || position > srcEnd) {
			error.incomplete = true;
		}
		throw error;
	}
}

function restoreStructures() {
	for (let id in currentStructures.restoreStructures) {
		currentStructures[id] = currentStructures.restoreStructures[id];
	}
	currentStructures.restoreStructures = null;
}

export function read() {
	let token = src[position++];
	if (token < 0xa0) {
		if (token < 0x80) {
			if (token < 0x40)
				return token;
			else {
				let structure = currentStructures[token & 0x3f] ||
					currentUnpackr.getStructures && loadStructures()[token & 0x3f];
				if (structure) {
					if (!structure.read) {
						structure.read = createStructureReader(structure, token & 0x3f);
					}
					return structure.read();
				} else
					return token;
			}
		} else if (token < 0x90) {
			// map
			token -= 0x80;
			if (currentUnpackr.mapsAsObjects) {
				let object = {};
				for (let i = 0; i < token; i++) {
					let key = readKey();
					if (key === '__proto__')
						key = '__proto_';
					object[key] = read();
				}
				return object;
			} else {
				let map = new Map();
				for (let i = 0; i < token; i++) {
					map.set(read(), read());
				}
				return map;
			}
		} else {
			token -= 0x90;
			let array = new Array(token);
			for (let i = 0; i < token; i++) {
				array[i] = read();
			}
			if (currentUnpackr.freezeData)
				return Object.freeze(array);
			return array;
		}
	} else if (token < 0xc0) {
		// fixstr
		let length = token - 0xa0;
		if (srcStringEnd >= position) {
			return srcString.slice(position - srcStringStart, (position += length) - srcStringStart);
		}
		if (srcStringEnd == 0 && srcEnd < 140) {
			// for small blocks, avoiding the overhead of the extract call is helpful
			let string = length < 16 ? shortStringInJS(length) : longStringInJS(length);
			if (string != null)
				return string;
		}
		return readFixedString(length);
	} else {
		let value;
		switch (token) {
			case 0xc0: return null;
			case 0xc1:
				if (bundledStrings) {
					value = read(); // followed by the length of the string in characters (not bytes!)
					if (value > 0)
						return bundledStrings[1].slice(bundledStrings.position1, bundledStrings.position1 += value);
					else
						return bundledStrings[0].slice(bundledStrings.position0, bundledStrings.position0 -= value);
				}
				return C1; // "never-used", return special object to denote that
			case 0xc2: return false;
			case 0xc3: return true;
			case 0xc4:
				// bin 8
				value = src[position++];
				if (value === undefined)
					throw new Error('Unexpected end of buffer');
				return readBin(value);
			case 0xc5:
				// bin 16
				value = dataView.getUint16(position);
				position += 2;
				return readBin(value);
			case 0xc6:
				// bin 32
				value = dataView.getUint32(position);
				position += 4;
				return readBin(value);
			case 0xc7:
				// ext 8
				return readExt(src[position++]);
			case 0xc8:
				// ext 16
				value = dataView.getUint16(position);
				position += 2;
				return readExt(value);
			case 0xc9:
				// ext 32
				value = dataView.getUint32(position);
				position += 4;
				return readExt(value);
			case 0xca:
				value = dataView.getFloat32(position);
				if (currentUnpackr.useFloat32 > 2) {
					// this does rounding of numbers that were encoded in 32-bit float to nearest significant decimal digit that could be preserved
					let multiplier = mult10[((src[position] & 0x7f) << 1) | (src[position + 1] >> 7)];
					position += 4;
					return ((multiplier * value + (value > 0 ? 0.5 : -0.5)) >> 0) / multiplier;
				}
				position += 4;
				return value;
			case 0xcb:
				value = dataView.getFloat64(position);
				position += 8;
				return value;
			// uint handlers
			case 0xcc:
				return src[position++];
			case 0xcd:
				value = dataView.getUint16(position);
				position += 2;
				return value;
			case 0xce:
				value = dataView.getUint32(position);
				position += 4;
				return value;
			case 0xcf:
				if (currentUnpackr.int64AsType === 'number') {
					value = dataView.getUint32(position) * 0x100000000;
					value += dataView.getUint32(position + 4);
				} else if (currentUnpackr.int64AsType === 'string') {
					value = dataView.getBigUint64(position).toString();
				} else if (currentUnpackr.int64AsType === 'auto') {
					value = dataView.getBigUint64(position);
					if (value<=BigInt(2)<<BigInt(52)) value=Number(value);
				} else
					value = dataView.getBigUint64(position);
				position += 8;
				return value;

			// int handlers
			case 0xd0:
				return dataView.getInt8(position++);
			case 0xd1:
				value = dataView.getInt16(position);
				position += 2;
				return value;
			case 0xd2:
				value = dataView.getInt32(position);
				position += 4;
				return value;
			case 0xd3:
				if (currentUnpackr.int64AsType === 'number') {
					value = dataView.getInt32(position) * 0x100000000;
					value += dataView.getUint32(position + 4);
				} else if (currentUnpackr.int64AsType === 'string') {
					value = dataView.getBigInt64(position).toString();
				} else if (currentUnpackr.int64AsType === 'auto') {
					value = dataView.getBigInt64(position);
					if (value>=BigInt(-2)<<BigInt(52)&&value<=BigInt(2)<<BigInt(52)) value=Number(value);
				} else
					value = dataView.getBigInt64(position);
				position += 8;
				return value;

			case 0xd4:
				// fixext 1
				value = src[position++];
				if (value == 0x72) {
					return recordDefinition(src[position++] & 0x3f);
				} else {
					let extension = currentExtensions[value];
					if (extension) {
						if (extension.read) {
							position++; // skip filler byte
							return extension.read(read());
						} else if (extension.noBuffer) {
							position++; // skip filler byte
							return extension();
						} else
							return extension(src.subarray(position, ++position));
					} else
						throw new Error('Unknown extension ' + value);
				}
			case 0xd5:
				// fixext 2
				value = src[position];
				if (value == 0x72) {
					position++;
					return recordDefinition(src[position++] & 0x3f, src[position++]);
				} else
					return readExt(2);
			case 0xd6:
				// fixext 4
				return readExt(4);
			case 0xd7:
				// fixext 8
				return readExt(8);
			case 0xd8:
				// fixext 16
				return readExt(16);
			case 0xd9:
			// str 8
				value = src[position++];
				if (srcStringEnd >= position) {
					return srcString.slice(position - srcStringStart, (position += value) - srcStringStart);
				}
				return readString8(value);
			case 0xda:
			// str 16
				value = dataView.getUint16(position);
				position += 2;
				if (srcStringEnd >= position) {
					return srcString.slice(position - srcStringStart, (position += value) - srcStringStart);
				}
				return readString16(value);
			case 0xdb:
			// str 32
				value = dataView.getUint32(position);
				position += 4;
				if (srcStringEnd >= position) {
					return srcString.slice(position - srcStringStart, (position += value) - srcStringStart);
				}
				return readString32(value);
			case 0xdc:
			// array 16
				value = dataView.getUint16(position);
				position += 2;
				return readArray(value);
			case 0xdd:
			// array 32
				value = dataView.getUint32(position);
				position += 4;
				return readArray(value);
			case 0xde:
			// map 16
				value = dataView.getUint16(position);
				position += 2;
				return readMap(value);
			case 0xdf:
			// map 32
				value = dataView.getUint32(position);
				position += 4;
				return readMap(value);
			default: // negative int
				if (token >= 0xe0)
					return token - 0x100;
				if (token === undefined) {
					let error = new Error('Unexpected end of MessagePack data');
					error.incomplete = true;
					throw error;
				}
				throw new Error('Unknown MessagePack token ' + token);

		}
	}
}
const validName = /^[a-zA-Z_$][a-zA-Z\d_$]*$/;
function createStructureReader(structure, firstId) {
	function readObject() {
		// This initial function is quick to instantiate, but runs slower. After several iterations pay the cost to build the faster function
		if (readObject.count++ > inlineObjectReadThreshold) {
			let optimizedReadObject;
			try {
				optimizedReadObject = structure.read = (new Function('r', 'return function(){return ' + (currentUnpackr.freezeData ? 'Object.freeze' : '') +
					'({' + structure.map(key => key === '__proto__' ? '__proto_:r()' : validName.test(key) ? key + ':r()' : ('[' + JSON.stringify(key) + ']:r()')).join(',') + '})}'))(read);
			} catch(error) {
				// in CF workers, the new Function call could begin to fail at any point in time
				inlineObjectReadThreshold = Infinity; // disable going forward
				return readObject(); // recursively try again
			}
			structure.read0 = optimizedReadObject; // keep the un-wrapped body reader in sync
			if (structure.highByte === 0)
				structure.read = createSecondByteReader(firstId, structure.read);
			return optimizedReadObject(); // second byte is already read, if there is one so immediately read object
		}
		let object = {};
		for (let i = 0, l = structure.length; i < l; i++) {
			let key = structure[i];
			if (key === '__proto__')
				key = '__proto_';
			object[key] = read();
		}
		if (currentUnpackr.freezeData)
			return Object.freeze(object);
		return object;
	}
	readObject.count = 0;
	// read0 is the un-wrapped body reader: it reads the record's values directly without
	// consuming a leading high byte. recordDefinition uses it for the immediate read that follows
	// a record definition (the high byte, if present, was already consumed). For highByte === 0
	// structures the public reader is a second-byte reader (used by later references), but the
	// definition read itself must not consume that byte.
	structure.read0 = readObject;
	if (structure.highByte === 0) {
		return createSecondByteReader(firstId, readObject);
	}
	return readObject;
}

const createSecondByteReader = (firstId, read0) => {
	return function() {
		let highByte = src[position++];
		if (highByte === 0)
			return read0();
		let id = firstId < 32 ? -(firstId + (highByte << 5)) : firstId + (highByte << 5);
		let structure = currentStructures[id] || loadStructures()[id];
		if (!structure) {
			throw new Error('Record id is not defined for ' + id);
		}
		if (!structure.read)
			structure.read = createStructureReader(structure, firstId);
		return structure.read();
	};
};

export function loadStructures() {
	let loadedStructures = saveState(() => {
		// save the state in case getStructures modifies our buffer
		src = null;
		return currentUnpackr.getStructures();
	});
	return currentStructures = currentUnpackr._mergeStructures(loadedStructures, currentStructures);
}

var readFixedString = readStringJS;
var readString8 = readStringJS;
var readString16 = readStringJS;
var readString32 = readStringJS;
export let isNativeAccelerationEnabled = false;

export function setExtractor(extractStrings) {
	isNativeAccelerationEnabled = true;
	readFixedString = readString(1);
	readString8 = readString(2);
	readString16 = readString(3);
	readString32 = readString(5);
	function readString(headerLength) {
		return function readString(length) {
			let string = strings[stringPosition++];
			if (string == null) {
				if (bundledStrings)
					return readStringJS(length);
				let byteOffset = src.byteOffset;
				let extraction = extractStrings(position - headerLength + byteOffset, srcEnd + byteOffset, src.buffer);
				if (typeof extraction == 'string') {
					string = extraction;
					strings = EMPTY_ARRAY;
				} else {
					strings = extraction;
					stringPosition = 1;
					srcStringEnd = 1; // even if a utf-8 string was decoded, must indicate we are in the midst of extracted strings and can't skip strings
					string = strings[0];
					if (string === undefined)
						throw new Error('Unexpected end of buffer');
				}
			}
			let srcStringLength = string.length;
			if (srcStringLength <= length) {
				position += length;
				return string;
			}
			srcString = string;
			srcStringStart = position;
			srcStringEnd = position + srcStringLength;
			position += length;
			return string.slice(0, length); // we know we just want the beginning
		};
	}
}
function readStringJS(length) {
	let result;
	if (length < 16) {
		if (result = shortStringInJS(length))
			return result;
	}
	if (length > 64 && decoder)
		return decoder.decode(src.subarray(position, position += length));
	const end = position + length;
	const units = [];
	result = '';
	while (position < end) {
		const byte1 = src[position++];
		if ((byte1 & 0x80) === 0) {
			// 1 byte
			units.push(byte1);
		} else if ((byte1 & 0xe0) === 0xc0) {
			// 2 bytes
			const byte2 = src[position++] & 0x3f;
			const codePoint = ((byte1 & 0x1f) << 6) | byte2;
			// Reject overlong encoding: 2-byte sequences must encode values >= 0x80
			if (codePoint < 0x80) {
				units.push(0xFFFD); // replacement character
			} else {
				units.push(codePoint);
			}
		} else if ((byte1 & 0xf0) === 0xe0) {
			// 3 bytes
			const byte2 = src[position++] & 0x3f;
			const byte3 = src[position++] & 0x3f;
			const codePoint = ((byte1 & 0x1f) << 12) | (byte2 << 6) | byte3;
			// Reject overlong encoding: 3-byte sequences must encode values >= 0x800
			// Also reject surrogates (0xD800-0xDFFF)
			if (codePoint < 0x800 || (codePoint >= 0xD800 && codePoint <= 0xDFFF)) {
				units.push(0xFFFD); // replacement character
			} else {
				units.push(codePoint);
			}
		} else if ((byte1 & 0xf8) === 0xf0) {
			// 4 bytes
			const byte2 = src[position++] & 0x3f;
			const byte3 = src[position++] & 0x3f;
			const byte4 = src[position++] & 0x3f;
			let unit = ((byte1 & 0x07) << 0x12) | (byte2 << 0x0c) | (byte3 << 0x06) | byte4;
			// Reject overlong encoding: 4-byte sequences must encode values >= 0x10000
			// Also reject values > 0x10FFFF (maximum valid Unicode)
			if (unit < 0x10000 || unit > 0x10FFFF) {
				units.push(0xFFFD); // replacement character
			} else if (unit > 0xffff) {
				unit -= 0x10000;
				units.push(((unit >>> 10) & 0x3ff) | 0xd800);
				unit = 0xdc00 | (unit & 0x3ff);
				units.push(unit);
			} else {
				units.push(unit);
			}
		} else {
			units.push(0xFFFD); // replacement character for invalid lead byte
		}

		if (units.length >= 0x1000) {
			result += fromCharCode.apply(String, units);
			units.length = 0;
		}
	}

	if (units.length > 0) {
		result += fromCharCode.apply(String, units);
	}

	return result;
}
export function readString(source, start, length) {
	let existingSrc = src;
	src = source;
	position = start;
	try {
		return readStringJS(length);
	} finally {
		src = existingSrc;
	}
}

function readArray(length) {
	let array = new Array(length);
	for (let i = 0; i < length; i++) {
		array[i] = read();
	}
	if (currentUnpackr.freezeData)
		return Object.freeze(array);
	return array;
}

function readMap(length) {
	if (currentUnpackr.mapsAsObjects) {
		let object = {};
		for (let i = 0; i < length; i++) {
			let key = readKey();
			if (key === '__proto__')
				key = '__proto_';
			object[key] = read();
		}
		return object;
	} else {
		let map = new Map();
		for (let i = 0; i < length; i++) {
			map.set(read(), read());
		}
		return map;
	}
}

var fromCharCode = String.fromCharCode;
function longStringInJS(length) {
	let start = position;
	let bytes = new Array(length);
	for (let i = 0; i < length; i++) {
		const byte = src[position++];
		if ((byte & 0x80) > 0) {
				position = start;
				return;
			}
			bytes[i] = byte;
		}
		return fromCharCode.apply(String, bytes);
}
function shortStringInJS(length) {
	if (length < 4) {
		if (length < 2) {
			if (length === 0)
				return '';
			else {
				let a = src[position++];
				if ((a & 0x80) > 1) {
					position -= 1;
					return;
				}
				return fromCharCode(a);
			}
		} else {
			let a = src[position++];
			let b = src[position++];
			if ((a & 0x80) > 0 || (b & 0x80) > 0) {
				position -= 2;
				return;
			}
			if (length < 3)
				return fromCharCode(a, b);
			let c = src[position++];
			if ((c & 0x80) > 0) {
				position -= 3;
				return;
			}
			return fromCharCode(a, b, c);
		}
	} else {
		let a = src[position++];
		let b = src[position++];
		let c = src[position++];
		let d = src[position++];
		if ((a & 0x80) > 0 || (b & 0x80) > 0 || (c & 0x80) > 0 || (d & 0x80) > 0) {
			position -= 4;
			return;
		}
		if (length < 6) {
			if (length === 4)
				return fromCharCode(a, b, c, d);
			else {
				let e = src[position++];
				if ((e & 0x80) > 0) {
					position -= 5;
					return;
				}
				return fromCharCode(a, b, c, d, e);
			}
		} else if (length < 8) {
			let e = src[position++];
			let f = src[position++];
			if ((e & 0x80) > 0 || (f & 0x80) > 0) {
				position -= 6;
				return;
			}
			if (length < 7)
				return fromCharCode(a, b, c, d, e, f);
			let g = src[position++];
			if ((g & 0x80) > 0) {
				position -= 7;
				return;
			}
			return fromCharCode(a, b, c, d, e, f, g);
		} else {
			let e = src[position++];
			let f = src[position++];
			let g = src[position++];
			let h = src[position++];
			if ((e & 0x80) > 0 || (f & 0x80) > 0 || (g & 0x80) > 0 || (h & 0x80) > 0) {
				position -= 8;
				return;
			}
			if (length < 10) {
				if (length === 8)
					return fromCharCode(a, b, c, d, e, f, g, h);
				else {
					let i = src[position++];
					if ((i & 0x80) > 0) {
						position -= 9;
						return;
					}
					return fromCharCode(a, b, c, d, e, f, g, h, i);
				}
			} else if (length < 12) {
				let i = src[position++];
				let j = src[position++];
				if ((i & 0x80) > 0 || (j & 0x80) > 0) {
					position -= 10;
					return;
				}
				if (length < 11)
					return fromCharCode(a, b, c, d, e, f, g, h, i, j);
				let k = src[position++];
				if ((k & 0x80) > 0) {
					position -= 11;
					return;
				}
				return fromCharCode(a, b, c, d, e, f, g, h, i, j, k);
			} else {
				let i = src[position++];
				let j = src[position++];
				let k = src[position++];
				let l = src[position++];
				if ((i & 0x80) > 0 || (j & 0x80) > 0 || (k & 0x80) > 0 || (l & 0x80) > 0) {
					position -= 12;
					return;
				}
				if (length < 14) {
					if (length === 12)
						return fromCharCode(a, b, c, d, e, f, g, h, i, j, k, l);
					else {
						let m = src[position++];
						if ((m & 0x80) > 0) {
							position -= 13;
							return;
						}
						return fromCharCode(a, b, c, d, e, f, g, h, i, j, k, l, m);
					}
				} else {
					let m = src[position++];
					let n = src[position++];
					if ((m & 0x80) > 0 || (n & 0x80) > 0) {
						position -= 14;
						return;
					}
					if (length < 15)
						return fromCharCode(a, b, c, d, e, f, g, h, i, j, k, l, m, n);
					let o = src[position++];
					if ((o & 0x80) > 0) {
						position -= 15;
						return;
					}
					return fromCharCode(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o);
				}
			}
		}
	}
}

function readOnlyJSString() {
	let token = src[position++];
	let length;
	if (token < 0xc0) {
		// fixstr
		length = token - 0xa0;
	} else {
		switch(token) {
			case 0xd9:
			// str 8
				length = src[position++];
				break;
			case 0xda:
			// str 16
				length = dataView.getUint16(position);
				position += 2;
				break;
			case 0xdb:
			// str 32
				length = dataView.getUint32(position);
				position += 4;
				break;
			default:
				throw new Error('Expected string');
		}
	}
	return readStringJS(length);
}


function readBin(length) {
	return currentUnpackr.copyBuffers ?
		// specifically use the copying slice (not the node one)
		Uint8Array.prototype.slice.call(src, position, position += length) :
		src.subarray(position, position += length);
}
function readExt(length) {
	let type = src[position++];
	if (currentExtensions[type]) {
		let end;
		return currentExtensions[type](src.subarray(position, end = (position += length)), (readPosition) => {
			position = readPosition;
			try {
				return read();
			} finally {
				position = end;
			}
		});
	}
	else
		throw new Error('Unknown extension type ' + type);
}

var keyCache = new Array(4096);
function readKey() {
	let length = src[position++];
	if (length >= 0xa0 && length < 0xc0) {
		// fixstr, potentially use key cache
		length = length - 0xa0;
		if (srcStringEnd >= position) // if it has been extracted, must use it (and faster anyway)
			return srcString.slice(position - srcStringStart, (position += length) - srcStringStart);
		else if (!(srcStringEnd == 0 && srcEnd < 180))
			return readFixedString(length);
	} else { // not cacheable, go back and do a standard read
		position--;
		return asSafeString(read());
	}
	let key = ((length << 5) ^ (length > 1 ? dataView.getUint16(position) : length > 0 ? src[position] : 0)) & 0xfff;
	let entry = keyCache[key];
	let checkPosition = position;
	let end = position + length - 3;
	let chunk;
	let i = 0;
	if (entry && entry.bytes == length) {
		while (checkPosition < end) {
			chunk = dataView.getUint32(checkPosition);
			if (chunk != entry[i++]) {
				checkPosition = 0x70000000;
				break;
			}
			checkPosition += 4;
		}
		end += 3;
		while (checkPosition < end) {
			chunk = src[checkPosition++];
			if (chunk != entry[i++]) {
				checkPosition = 0x70000000;
				break;
			}
		}
		if (checkPosition === end) {
			position = checkPosition;
			return entry.string;
		}
		end -= 3;
		checkPosition = position;
	}
	entry = [];
	keyCache[key] = entry;
	entry.bytes = length;
	while (checkPosition < end) {
		chunk = dataView.getUint32(checkPosition);
		entry.push(chunk);
		checkPosition += 4;
	}
	end += 3;
	while (checkPosition < end) {
		chunk = src[checkPosition++];
		entry.push(chunk);
	}
	// for small blocks, avoiding the overhead of the extract call is helpful
	let string = length < 16 ? shortStringInJS(length) : longStringInJS(length);
	if (string != null)
		return entry.string = string;
	return entry.string = readFixedString(length);
}

function asSafeString(property) {
	// protect against expensive (DoS) string conversions
	if (typeof property === 'string') return property;
	if (typeof property === 'number' || typeof property === 'boolean' || typeof property === 'bigint') return property.toString();
	if (property == null) return property + '';
	if (currentUnpackr.allowArraysInMapKeys && Array.isArray(property) && property.flat().every(item => ['string', 'number', 'boolean', 'bigint'].includes(typeof item))) {
		return property.flat().toString();
	}
	throw new Error(`Invalid property type for record: ${typeof property}`);
}
// the registration of the record definition extension (as "r")
const recordDefinition = (id, highByte) => {
	let structure = read().map(asSafeString); // ensure that all keys are strings and
	// that the array is mutable
	let firstByte = id;
	if (highByte !== undefined) {
		id = id < 32 ? -((highByte << 5) + id) : ((highByte << 5) + id);
		structure.highByte = highByte;
	}
	let existingStructure = currentStructures[id];
	// If it is a shared structure, we need to restore any changes after reading.
	// Also in sequential mode, we may get incomplete reads and thus errors, and we need to restore
	// to the state prior to an incomplete read in order to properly resume.
	if (existingStructure && (existingStructure.isShared || sequentialMode)) {
		(currentStructures.restoreStructures || (currentStructures.restoreStructures = []))[id] = existingStructure;
	}
	currentStructures[id] = structure;
	structure.read = createStructureReader(structure, firstByte);
	// The high byte (if any) was already consumed as the `highByte` argument above, so read the
	// record body directly. Going through structure.read (a second-byte reader when highByte === 0)
	// would misinterpret the first value byte as a high byte — corrupting two-byte own-record
	// definitions (0xd5 0x72 ...). createStructureReader stashes the un-wrapped body reader on
	// structure.read0 precisely for this immediate post-definition read.
	return (structure.read0 || structure.read)();
};
currentExtensions[0] = () => {}; // notepack defines extension 0 to mean undefined, so use that as the default here
currentExtensions[0].noBuffer = true;

currentExtensions[0x42] = data => {
	let headLength = (data.byteLength % 8) || 8;
	let head = BigInt(data[0] & 0x80 ? data[0] - 0x100 : data[0]);
	for (let i = 1; i < headLength; i++) {
		head <<= BigInt(8);
		head += BigInt(data[i]);
	}
	if (data.byteLength !== headLength) {
		let view = new DataView(data.buffer, data.byteOffset, data.byteLength);
		let decode = (start, end) => {
			let length = end - start;
			if (length <= 40) {
				let out = view.getBigUint64(start);
				for (let i = start + 8; i < end; i += 8) {
					out <<= BigInt(64);
					out |= view.getBigUint64(i);
				}
				return out;
			}
			// if (length === 8) return view.getBigUint64(start)
			let middle = start + (length >> 4 << 3);
			let left = decode(start, middle);
			let right = decode(middle, end);
			return (left << BigInt((end - middle) * 8)) | right;
		};
		head = (head << BigInt((view.byteLength - headLength) * 8)) | decode(headLength, view.byteLength);
	}
	return head;
};

let errors = {
	Error, EvalError, RangeError, ReferenceError, SyntaxError, TypeError, URIError, AggregateError: typeof AggregateError === 'function' ? AggregateError : null,
};
currentExtensions[0x65] = () => {
	let data = read();
	if (!errors[data[0]]) {
		let error = Error(data[1], { cause: data[2] });
		error.name = data[0];
		return error;
	}
	return errors[data[0]](data[1], { cause: data[2] });
};

currentExtensions[0x69] = (data) => {
	// id extension (for structured clones)
	if (currentUnpackr.structuredClone === false) throw new Error('Structured clone extension is disabled');
	let id = dataView.getUint32(position - 4);
	if (!referenceMap)
		referenceMap = new Map();
	let token = src[position];
	let target;
	// TODO: handle any other types that can cycle and make the code more robust if there are other extensions
	if (token >= 0x90 && token < 0xa0 || token == 0xdc || token == 0xdd)
		target = [];
	else if (token >= 0x80 && token < 0x90 || token == 0xde || token == 0xdf)
		target = new Map();
	else if ((token >= 0xc7 && token <= 0xc9 || token >= 0xd4 && token <= 0xd8) && src[position + 1] === 0x73)
		target = new Set();
	else
		target = {};

	let refEntry = { target }; // a placeholder object
	referenceMap.set(id, refEntry);
	let targetProperties = read(); // read the next value as the target object to id
	if (!refEntry.used) {
		// no cycle, can just use the returned read object
		return refEntry.target = targetProperties; // replace the placeholder with the real one
	} else {
		// there is a cycle, so we have to assign properties to original target
		Object.assign(target, targetProperties);
	}

	// copy over map/set entries if we're able to
	if (target instanceof Map)
		for (let [k, v] of targetProperties.entries()) target.set(k, v);
	if (target instanceof Set)
		for (let i of Array.from(targetProperties)) target.add(i);
	return target;
};

currentExtensions[0x70] = (data) => {
	// pointer extension (for structured clones)
	if (currentUnpackr.structuredClone === false) throw new Error('Structured clone extension is disabled');
	let id = dataView.getUint32(position - 4);
	let refEntry = referenceMap.get(id);
	refEntry.used = true;
	return refEntry.target;
};

currentExtensions[0x73] = () => new Set(read());

export const typedArrays = ['Int8','Uint8','Uint8Clamped','Int16','Uint16','Int32','Uint32','Float32','Float64','BigInt64','BigUint64'].map(type => type + 'Array');

let glbl = typeof globalThis === 'object' ? globalThis : window;
currentExtensions[0x74] = (data) => {
	let typeCode = data[0];
	// we always have to slice to get a new ArrayBuffer that is aligned
	let buffer = Uint8Array.prototype.slice.call(data, 1).buffer;

	let typedArrayName = typedArrays[typeCode];
	if (!typedArrayName) {
		if (typeCode === 16) return buffer;
		if (typeCode === 17) return new DataView(buffer);
		throw new Error('Could not find typed array for code ' + typeCode);
	}
	return new glbl[typedArrayName](buffer);
};
currentExtensions[0x78] = () => {
	let data = read();
	return new RegExp(data[0], data[1]);
};
const TEMP_BUNDLE = [];
currentExtensions[0x62] = (data) => {
	let dataSize = (data[0] << 24) + (data[1] << 16) + (data[2] << 8) + data[3];
	let dataPosition = position;
	position += dataSize - data.length;
	bundledStrings = TEMP_BUNDLE;
	bundledStrings = [readOnlyJSString(), readOnlyJSString()];
	bundledStrings.position0 = 0;
	bundledStrings.position1 = 0;
	bundledStrings.postBundlePosition = position;
	position = dataPosition;
	return read();
};

currentExtensions[0xff] = (data) => {
	// 32-bit date extension
	if (data.length == 4)
		return new Date((data[0] * 0x1000000 + (data[1] << 16) + (data[2] << 8) + data[3]) * 1000);
	else if (data.length == 8)
		return new Date(
			((data[0] << 22) + (data[1] << 14) + (data[2] << 6) + (data[3] >> 2)) / 1000000 +
			((data[3] & 0x3) * 0x100000000 + data[4] * 0x1000000 + (data[5] << 16) + (data[6] << 8) + data[7]) * 1000);
	else if (data.length == 12)
		return new Date(
			((data[0] << 24) + (data[1] << 16) + (data[2] << 8) + data[3]) / 1000000 +
			(((data[4] & 0x80) ? -0x1000000000000 : 0) + data[6] * 0x10000000000 + data[7] * 0x100000000 + data[8] * 0x1000000 + (data[9] << 16) + (data[10] << 8) + data[11]) * 1000);
	else
		return new Date('invalid');
};
// registration of bulk record definition?
// currentExtensions[0x52] = () =>

function saveState(callback) {
	if (currentUnpackr && currentUnpackr._onSaveState)
		currentUnpackr._onSaveState();
	let savedSrcEnd = srcEnd;
	let savedPosition = position;
	let savedStringPosition = stringPosition;
	let savedSrcStringStart = srcStringStart;
	let savedSrcStringEnd = srcStringEnd;
	let savedSrcString = srcString;
	let savedStrings = strings;
	let savedReferenceMap = referenceMap;
	let savedBundledStrings = bundledStrings;

	// TODO: We may need to revisit this if we do more external calls to user code (since it could be slow)
	let savedSrc = new Uint8Array(src.slice(0, srcEnd)); // we copy the data in case it changes while external data is processed
	let savedStructures = currentStructures;
	let savedStructuresContents = currentStructures.slice(0, currentStructures.length);
	let savedPackr = currentUnpackr;
	let savedSequentialMode = sequentialMode;
	let value = callback();
	srcEnd = savedSrcEnd;
	position = savedPosition;
	stringPosition = savedStringPosition;
	srcStringStart = savedSrcStringStart;
	srcStringEnd = savedSrcStringEnd;
	srcString = savedSrcString;
	strings = savedStrings;
	referenceMap = savedReferenceMap;
	bundledStrings = savedBundledStrings;
	src = savedSrc;
	sequentialMode = savedSequentialMode;
	currentStructures = savedStructures;
	currentStructures.splice(0, currentStructures.length, ...savedStructuresContents);
	currentUnpackr = savedPackr;
	dataView = new DataView(src.buffer, src.byteOffset, src.byteLength);
	return value;
}
export function clearSource() {
	src = null;
	referenceMap = null;
	currentStructures = null;
}

export function addExtension(extension) {
	if (extension.unpack)
		currentExtensions[extension.type] = extension.unpack;
	else
		currentExtensions[extension.type] = extension;
}

export const mult10 = new Array(147); // this is a table matching binary exponents to the multiplier to determine significant digit rounding
for (let i = 0; i < 256; i++) {
	mult10[i] = +('1e' + Math.floor(45.15 - i * 0.30103));
}
export const Decoder = Unpackr;
var defaultUnpackr = new Unpackr({ useRecords: false });
export const unpack = defaultUnpackr.unpack;
export const unpackMultiple = defaultUnpackr.unpackMultiple;
export const decode = defaultUnpackr.unpack;
export const FLOAT32_OPTIONS = {
	NEVER: 0,
	ALWAYS: 1,
	DECIMAL_ROUND: 3,
	DECIMAL_FIT: 4
};
let f32Array = new Float32Array(1);
let u8Array = new Uint8Array(f32Array.buffer, 0, 4);
export function roundFloat32(float32Number) {
	f32Array[0] = float32Number;
	let multiplier = mult10[((u8Array[3] & 0x7f) << 1) | (u8Array[2] >> 7)];
	return ((multiplier * float32Number + (float32Number > 0 ? 0.5 : -0.5)) >> 0) / multiplier;
}
// Marker for downstream libraries (e.g. structon) to detect per-instance
// struct-decoding hooks (this._readStruct, this._onLoadedStructures,
// this._onSaveState).  See `checkedRead` for the dispatch.
Unpackr.SUPPORTS_STRUCT_HOOKS = true;