forked from sheetjs/sheetjs
48 lines
1.4 KiB
JavaScript
48 lines
1.4 KiB
JavaScript
var Base64 = function() {
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var map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
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return {
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encode: function(input) {
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var o = "";
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var c1 = 0, c2 = 0, c3 = 0, e1 = 0, e2 = 0, e3 = 0, e4 = 0;
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for (var i = 0; i < input.length; ) {
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c1 = input.charCodeAt(i++);
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e1 = c1 >> 2;
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c2 = input.charCodeAt(i++);
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e2 = (c1 & 3) << 4 | c2 >> 4;
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c3 = input.charCodeAt(i++);
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e3 = (c2 & 15) << 2 | c3 >> 6;
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e4 = c3 & 63;
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if (isNaN(c2)) {
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e3 = e4 = 64;
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} else if (isNaN(c3)) {
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e4 = 64;
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}
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o += map.charAt(e1) + map.charAt(e2) + map.charAt(e3) + map.charAt(e4);
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}
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return o;
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},
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decode: function(input) {
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var o = "";
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var c1 = 0, c2 = 0, c3 = 0, e1 = 0, e2 = 0, e3 = 0, e4 = 0;
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input = input.replace(/[^\w\+\/\=]/g, "");
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for (var i = 0; i < input.length; ) {
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e1 = map.indexOf(input.charAt(i++));
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e2 = map.indexOf(input.charAt(i++));
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c1 = e1 << 2 | e2 >> 4;
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o += String.fromCharCode(c1);
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e3 = map.indexOf(input.charAt(i++));
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c2 = (e2 & 15) << 4 | e3 >> 2;
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if (e3 !== 64) {
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o += String.fromCharCode(c2);
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}
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e4 = map.indexOf(input.charAt(i++));
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c3 = (e3 & 3) << 6 | e4;
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if (e4 !== 64) {
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o += String.fromCharCode(c3);
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}
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}
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return o;
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}
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};
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}();
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