Subversion-Projekte lars-tiefland.cienc

/*

 * Copyright (c) 2012 chick307 <chick307@gmail.com>

 *

 * Licensed under the MIT License.

 * http://opensource.org/licenses/mit-license

 */

void function(global, callback) {

	if (typeof module === 'object') {

		module.exports = callback();

	} else if (typeof define === 'function') {

		define(callback);

	} else {

		global.adler32cs = callback();

	}

}(this, function() {

	var _hasArrayBuffer = typeof ArrayBuffer === 'function' &&

		typeof Uint8Array === 'function';

	var _Buffer = null, _isBuffer = (function() {

		if (!_hasArrayBuffer)

			return function _isBuffer() { return false };

		try {

			var buffer = require('buffer');

			if (typeof buffer.Buffer === 'function')

				_Buffer = buffer.Buffer;

		} catch (error) {}

		return function _isBuffer(value) {

			return value instanceof ArrayBuffer ||

				_Buffer !== null && value instanceof _Buffer;

		};

	}());

	var _utf8ToBinary = (function() {

		if (_Buffer !== null) {

			return function _utf8ToBinary(utf8String) {

				return new _Buffer(utf8String, 'utf8').toString('binary');

			};

		} else {

			return function _utf8ToBinary(utf8String) {

				return unescape(encodeURIComponent(utf8String));

			};

		}

	}());

	var MOD = 65521;

	var _update = function _update(checksum, binaryString) {

		var a = checksum & 0xFFFF, b = checksum >>> 16;

		for (var i = 0, length = binaryString.length; i < length; i++) {

			a = (a + (binaryString.charCodeAt(i) & 0xFF)) % MOD;

			b = (b + a) % MOD;

		}

		return (b << 16 | a) >>> 0;

	};

	var _updateUint8Array = function _updateUint8Array(checksum, uint8Array) {

		var a = checksum & 0xFFFF, b = checksum >>> 16;

		for (var i = 0, length = uint8Array.length, x; i < length; i++) {

			a = (a + uint8Array[i]) % MOD;

			b = (b + a) % MOD;

		}

		return (b << 16 | a) >>> 0

	};

	var exports = {};

	var Adler32 = exports.Adler32 = (function() {

		var ctor = function Adler32(checksum) {

			if (!(this instanceof ctor)) {

				throw new TypeError(

					'Constructor cannot called be as a function.');

			}

			if (!isFinite(checksum = checksum == null ? 1 : +checksum)) {

				throw new Error(

					'First arguments needs to be a finite number.');

			}

			this.checksum = checksum >>> 0;

		};

		var proto = ctor.prototype = {};

		proto.constructor = ctor;

		ctor.from = function(from) {

			from.prototype = proto;

			return from;

		}(function from(binaryString) {

			if (!(this instanceof ctor)) {

				throw new TypeError(

					'Constructor cannot called be as a function.');

			}

			if (binaryString == null)

				throw new Error('First argument needs to be a string.');

			this.checksum = _update(1, binaryString.toString());

		});

		ctor.fromUtf8 = function(fromUtf8) {

			fromUtf8.prototype = proto;

			return fromUtf8;

		}(function fromUtf8(utf8String) {

			if (!(this instanceof ctor)) {

				throw new TypeError(

					'Constructor cannot called be as a function.');

			}

			if (utf8String == null)

				throw new Error('First argument needs to be a string.');

			var binaryString = _utf8ToBinary(utf8String.toString());

			this.checksum = _update(1, binaryString);

		});

		if (_hasArrayBuffer) {

			ctor.fromBuffer = function(fromBuffer) {

				fromBuffer.prototype = proto;

				return fromBuffer;

			}(function fromBuffer(buffer) {

				if (!(this instanceof ctor)) {

					throw new TypeError(

						'Constructor cannot called be as a function.');

				}

				if (!_isBuffer(buffer))

					throw new Error('First argument needs to be ArrayBuffer.');

				var array = new Uint8Array(buffer);

				return this.checksum = _updateUint8Array(1, array);

			});

		}

		proto.update = function update(binaryString) {

			if (binaryString == null)

				throw new Error('First argument needs to be a string.');

			binaryString = binaryString.toString();

			return this.checksum = _update(this.checksum, binaryString);

		};

		proto.updateUtf8 = function updateUtf8(utf8String) {

			if (utf8String == null)

				throw new Error('First argument needs to be a string.');

			var binaryString = _utf8ToBinary(utf8String.toString());

			return this.checksum = _update(this.checksum, binaryString);

		};

		if (_hasArrayBuffer) {

			proto.updateBuffer = function updateBuffer(buffer) {

				if (!_isBuffer(buffer))

					throw new Error('First argument needs to be ArrayBuffer.');

				var array = new Uint8Array(buffer);

				return this.checksum = _updateUint8Array(this.checksum, array);

			};

		}

		proto.clone = function clone() {

			return new Adler32(this.checksum);

		};

		return ctor;

	}());

	exports.from = function from(binaryString) {

		if (binaryString == null)

			throw new Error('First argument needs to be a string.');

		return _update(1, binaryString.toString());

	};

	exports.fromUtf8 = function fromUtf8(utf8String) {

		if (utf8String == null)

			throw new Error('First argument needs to be a string.');

		var binaryString = _utf8ToBinary(utf8String.toString());

		return _update(1, binaryString);

	};

	if (_hasArrayBuffer) {

		exports.fromBuffer = function fromBuffer(buffer) {

			if (!_isBuffer(buffer))

				throw new Error('First argument need to be ArrayBuffer.');

			var array = new Uint8Array(buffer);

			return _updateUint8Array(1, array);

		};

	}

	return exports;

});