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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 1.4.4
- var LZString = (function() {
- // private property
- var f = String.fromCharCode;
- var keyStrBase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
- var keyStrUriSafe = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-$";
- var baseReverseDic = {};
- function getBaseValue(alphabet, character) {
- if (!baseReverseDic[alphabet]) {
- baseReverseDic[alphabet] = {};
- for (var i=0 ; i<alphabet.length ; i++) {
- baseReverseDic[alphabet][alphabet.charAt(i)] = i;
- }
- }
- return baseReverseDic[alphabet][character];
- }
- var LZString = {
- compressToBase64 : function (input) {
- if (input == null) return "";
- var res = LZString._compress(input, 6, function(a){return 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 getBaseValue(keyStrBase64, input.charAt(index)); });
- },
- compressToUTF16 : function (input) {
- if (input == null) return "";
- return LZString._compress(input, 15, function(a){return f(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(f(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 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 getBaseValue(keyStrUriSafe, input.charAt(index)); });
- },
- compress: function (uncompressed) {
- return LZString._compress(uncompressed, 16, function(a){return f(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;
- for (ii = 0; ii < uncompressed.length; ii += 1) {
- context_c = uncompressed.charAt(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,
- 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.charAt(0);
- } else {
- return null;
- }
- }
- result.push(entry);
- // Add w+entry[0] to the dictionary.
- dictionary[dictSize++] = w + entry.charAt(0);
- enlargeIn--;
- w = entry;
- if (enlargeIn == 0) {
- enlargeIn = Math.pow(2, numBits);
- numBits++;
- }
- }
- }
- };
- return LZString;
- })();
- if (typeof define === 'function' && define.amd) {
- define(function () { return LZString; });
- } else if( typeof module !== 'undefined' && module != null ) {
- module.exports = LZString
- }
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