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- // Copyright (c) 2013 Pieroxy <pieroxy@pieroxy.net>
- // This work is free. You can redistribute it and/or modify it
- // under the terms of the WTFPL, Version 2
- // For more information see LICENSE.txt or http://www.wtfpl.net/
- //
- // For more information, the home page:
- // http://pieroxy.net/blog/pages/lz-string/testing.html
- //
- // LZ-based compression algorithm, version 1.4.2
- var LZString = {
- // private property
- _f: String.fromCharCode,
- _keyStrBase64: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
- _keyStrUriSafe: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-$",
- _getBaseValue: function (alphabet, character) {
- if (!LZString._baseReverseDic) LZString._baseReverseDic = {};
- if (!LZString._baseReverseDic[alphabet]) {
- LZString._baseReverseDic[alphabet] = {};
- for (var i = 0 ; i < alphabet.length ; i++) {
- LZString._baseReverseDic[alphabet][alphabet[i]] = i;
- }
- }
- return LZString._baseReverseDic[alphabet][character];
- },
- compressToBase64: function (input) {
- if (input == null) return "";
- var res = LZString._compress(input, 6, function (a) { return LZString._keyStrBase64.charAt(a); });
- switch (res.length % 4) { // To produce valid Base64
- default: // When could this happen ?
- case 0: return res;
- case 1: return res + "===";
- case 2: return res + "==";
- case 3: return res + "=";
- }
- },
- decompressFromBase64: function (input) {
- if (input == null) return "";
- if (input == "") return null;
- return LZString._decompress(input.length, 32, function (index) { return LZString._getBaseValue(LZString._keyStrBase64, input.charAt(index)); });
- },
- compressToUTF16: function (input) {
- if (input == null) return "";
- return LZString._compress(input, 15, function (a) { return String.fromCharCode(a + 32); }) + " ";
- },
- decompressFromUTF16: function (compressed) {
- if (compressed == null) return "";
- if (compressed == "") return null;
- return LZString._decompress(compressed.length, 16384, function (index) { return compressed.charCodeAt(index) - 32; });
- },
- //compress into uint8array (UCS-2 big endian format)
- compressToUint8Array: function (uncompressed) {
- var compressed = LZString.compress(uncompressed);
- var buf = new Uint8Array(compressed.length * 2); // 2 bytes per character
- for (var i = 0, TotalLen = compressed.length; i < TotalLen; i++) {
- var current_value = compressed.charCodeAt(i);
- buf[i * 2] = current_value >>> 8;
- buf[i * 2 + 1] = current_value % 256;
- }
- return buf;
- },
- //decompress from uint8array (UCS-2 big endian format)
- decompressFromUint8Array: function (compressed) {
- if (compressed === null || compressed === undefined) {
- return LZString.decompress(compressed);
- } else {
- var buf = new Array(compressed.length / 2); // 2 bytes per character
- for (var i = 0, TotalLen = buf.length; i < TotalLen; i++) {
- buf[i] = compressed[i * 2] * 256 + compressed[i * 2 + 1];
- }
- var result = [];
- buf.forEach(function (c) {
- result.push(String.fromCharCode(c));
- });
- return LZString.decompress(result.join(''));
- }
- },
- //compress into a string that is already URI encoded
- compressToEncodedURIComponent: function (input) {
- if (input == null) return "";
- return LZString._compress(input, 6, function (a) { return LZString._keyStrUriSafe.charAt(a); });
- },
- //decompress from an output of compressToEncodedURIComponent
- decompressFromEncodedURIComponent: function (input) {
- if (input == null) return "";
- if (input == "") return null;
- input = input.replace(/ /g, "+");
- return LZString._decompress(input.length, 32, function (index) { return LZString._getBaseValue(LZString._keyStrUriSafe, input.charAt(index)); });
- },
- compress: function (uncompressed) {
- return LZString._compress(uncompressed, 16, function (a) { return String.fromCharCode(a); });
- },
- _compress: function (uncompressed, bitsPerChar, getCharFromInt) {
- if (uncompressed == null) return "";
- var i, value,
- context_dictionary = {},
- context_dictionaryToCreate = {},
- context_c = "",
- context_wc = "",
- context_w = "",
- context_enlargeIn = 2, // Compensate for the first entry which should not count
- context_dictSize = 3,
- context_numBits = 2,
- context_data = [],
- context_data_val = 0,
- context_data_position = 0,
- ii,
- f = LZString._f;
- for (ii = 0; ii < uncompressed.length; ii += 1) {
- context_c = uncompressed[ii];
- if (!Object.prototype.hasOwnProperty.call(context_dictionary, context_c)) {
- context_dictionary[context_c] = context_dictSize++;
- context_dictionaryToCreate[context_c] = true;
- }
- context_wc = context_w + context_c;
- if (Object.prototype.hasOwnProperty.call(context_dictionary, context_wc)) {
- context_w = context_wc;
- } else {
- if (Object.prototype.hasOwnProperty.call(context_dictionaryToCreate, context_w)) {
- if (context_w.charCodeAt(0) < 256) {
- for (i = 0 ; i < context_numBits ; i++) {
- context_data_val = (context_data_val << 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- }
- value = context_w.charCodeAt(0);
- for (i = 0 ; i < 8 ; i++) {
- context_data_val = (context_data_val << 1) | (value & 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- value = value >> 1;
- }
- } else {
- value = 1;
- for (i = 0 ; i < context_numBits ; i++) {
- context_data_val = (context_data_val << 1) | value;
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- value = 0;
- }
- value = context_w.charCodeAt(0);
- for (i = 0 ; i < 16 ; i++) {
- context_data_val = (context_data_val << 1) | (value & 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- value = value >> 1;
- }
- }
- context_enlargeIn--;
- if (context_enlargeIn == 0) {
- context_enlargeIn = Math.pow(2, context_numBits);
- context_numBits++;
- }
- delete context_dictionaryToCreate[context_w];
- } else {
- value = context_dictionary[context_w];
- for (i = 0 ; i < context_numBits ; i++) {
- context_data_val = (context_data_val << 1) | (value & 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- value = value >> 1;
- }
- }
- context_enlargeIn--;
- if (context_enlargeIn == 0) {
- context_enlargeIn = Math.pow(2, context_numBits);
- context_numBits++;
- }
- // Add wc to the dictionary.
- context_dictionary[context_wc] = context_dictSize++;
- context_w = String(context_c);
- }
- }
- // Output the code for w.
- if (context_w !== "") {
- if (Object.prototype.hasOwnProperty.call(context_dictionaryToCreate, context_w)) {
- if (context_w.charCodeAt(0) < 256) {
- for (i = 0 ; i < context_numBits ; i++) {
- context_data_val = (context_data_val << 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- }
- value = context_w.charCodeAt(0);
- for (i = 0 ; i < 8 ; i++) {
- context_data_val = (context_data_val << 1) | (value & 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- value = value >> 1;
- }
- } else {
- value = 1;
- for (i = 0 ; i < context_numBits ; i++) {
- context_data_val = (context_data_val << 1) | value;
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- value = 0;
- }
- value = context_w.charCodeAt(0);
- for (i = 0 ; i < 16 ; i++) {
- context_data_val = (context_data_val << 1) | (value & 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- value = value >> 1;
- }
- }
- context_enlargeIn--;
- if (context_enlargeIn == 0) {
- context_enlargeIn = Math.pow(2, context_numBits);
- context_numBits++;
- }
- delete context_dictionaryToCreate[context_w];
- } else {
- value = context_dictionary[context_w];
- for (i = 0 ; i < context_numBits ; i++) {
- context_data_val = (context_data_val << 1) | (value & 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- value = value >> 1;
- }
- }
- context_enlargeIn--;
- if (context_enlargeIn == 0) {
- context_enlargeIn = Math.pow(2, context_numBits);
- context_numBits++;
- }
- }
- // Mark the end of the stream
- value = 2;
- for (i = 0 ; i < context_numBits ; i++) {
- context_data_val = (context_data_val << 1) | (value & 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data_position = 0;
- context_data.push(getCharFromInt(context_data_val));
- context_data_val = 0;
- } else {
- context_data_position++;
- }
- value = value >> 1;
- }
- // Flush the last char
- while (true) {
- context_data_val = (context_data_val << 1);
- if (context_data_position == bitsPerChar - 1) {
- context_data.push(getCharFromInt(context_data_val));
- break;
- }
- else context_data_position++;
- }
- return context_data.join('');
- },
- decompress: function (compressed) {
- if (compressed == null) return "";
- if (compressed == "") return null;
- return LZString._decompress(compressed.length, 32768, function (index) { return compressed.charCodeAt(index); });
- },
- _decompress: function (length, resetValue, getNextValue) {
- var dictionary = [],
- next,
- enlargeIn = 4,
- dictSize = 4,
- numBits = 3,
- entry = "",
- result = [],
- i,
- w,
- bits, resb, maxpower, power,
- c,
- f = LZString._f,
- data = { val: getNextValue(0), position: resetValue, index: 1 };
- for (i = 0; i < 3; i += 1) {
- dictionary[i] = i;
- }
- bits = 0;
- maxpower = Math.pow(2, 2);
- power = 1;
- while (power != maxpower) {
- resb = data.val & data.position;
- data.position >>= 1;
- if (data.position == 0) {
- data.position = resetValue;
- data.val = getNextValue(data.index++);
- }
- bits |= (resb > 0 ? 1 : 0) * power;
- power <<= 1;
- }
- switch (next = bits) {
- case 0:
- bits = 0;
- maxpower = Math.pow(2, 8);
- power = 1;
- while (power != maxpower) {
- resb = data.val & data.position;
- data.position >>= 1;
- if (data.position == 0) {
- data.position = resetValue;
- data.val = getNextValue(data.index++);
- }
- bits |= (resb > 0 ? 1 : 0) * power;
- power <<= 1;
- }
- c = f(bits);
- break;
- case 1:
- bits = 0;
- maxpower = Math.pow(2, 16);
- power = 1;
- while (power != maxpower) {
- resb = data.val & data.position;
- data.position >>= 1;
- if (data.position == 0) {
- data.position = resetValue;
- data.val = getNextValue(data.index++);
- }
- bits |= (resb > 0 ? 1 : 0) * power;
- power <<= 1;
- }
- c = f(bits);
- break;
- case 2:
- return "";
- }
- dictionary[3] = c;
- w = c;
- result.push(c);
- while (true) {
- if (data.index > length) {
- return "";
- }
- bits = 0;
- maxpower = Math.pow(2, numBits);
- power = 1;
- while (power != maxpower) {
- resb = data.val & data.position;
- data.position >>= 1;
- if (data.position == 0) {
- data.position = resetValue;
- data.val = getNextValue(data.index++);
- }
- bits |= (resb > 0 ? 1 : 0) * power;
- power <<= 1;
- }
- switch (c = bits) {
- case 0:
- bits = 0;
- maxpower = Math.pow(2, 8);
- power = 1;
- while (power != maxpower) {
- resb = data.val & data.position;
- data.position >>= 1;
- if (data.position == 0) {
- data.position = resetValue;
- data.val = getNextValue(data.index++);
- }
- bits |= (resb > 0 ? 1 : 0) * power;
- power <<= 1;
- }
- dictionary[dictSize++] = f(bits);
- c = dictSize - 1;
- enlargeIn--;
- break;
- case 1:
- bits = 0;
- maxpower = Math.pow(2, 16);
- power = 1;
- while (power != maxpower) {
- resb = data.val & data.position;
- data.position >>= 1;
- if (data.position == 0) {
- data.position = resetValue;
- data.val = getNextValue(data.index++);
- }
- bits |= (resb > 0 ? 1 : 0) * power;
- power <<= 1;
- }
- dictionary[dictSize++] = f(bits);
- c = dictSize - 1;
- enlargeIn--;
- break;
- case 2:
- return result.join('');
- }
- if (enlargeIn == 0) {
- enlargeIn = Math.pow(2, numBits);
- numBits++;
- }
- if (dictionary[c]) {
- entry = dictionary[c];
- } else {
- if (c === dictSize) {
- entry = w + w[0];
- } else {
- return null;
- }
- }
- result.push(entry);
- // Add w+entry[0] to the dictionary.
- dictionary[dictSize++] = w + entry[0];
- enlargeIn--;
- w = entry;
- if (enlargeIn == 0) {
- enlargeIn = Math.pow(2, numBits);
- numBits++;
- }
- }
- }
- };
- if (typeof module !== 'undefined' && module != null) {
- module.exports = LZString;
- }
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