57 lines
1.3 KiB
JavaScript
57 lines
1.3 KiB
JavaScript
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app.factory('$base64', [function() {
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var obj = {};
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var a64 = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',
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a256 = {
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indexOf: function (c) {
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return c.charCodeAt(0);
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},
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charAt: String.fromCharCode
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};
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function code(s, discard, alpha, beta, w1, w2) {
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s = String(s);
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var b = 0, x = '', i, c, bs = 1, sb = 1, length = s.length, tmp;
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for (i = 0; i < length || (!discard && sb > 1); i += 1) {
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b *= w1;
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bs *= w1;
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if (i < length) {
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c = alpha.indexOf(s.charAt(i));
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if (c <= -1 || c >= w1) {
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throw new RangeError();
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}
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sb *= w1;
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b += c;
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}
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while (bs >= w2) {
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bs /= w2;
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if (sb > 1) {
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tmp = b;
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b %= bs;
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x += beta.charAt((tmp - b) / bs);
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sb /= w2;
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}
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}
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}
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return x;
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}
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obj.btoa = function (s) {
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s = code(s, false, a256, a64, 256, 64);
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return s + '===='.slice((s.length % 4) || 4);
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};
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obj.atob = function (s) {
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var i;
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s = String(s).split('=');
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for (i = s.length - 1; i >= 0; i -= 1) {
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if (s[i].length % 4 === 1) {
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throw new RangeError();
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}
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s[i] = code(s[i], true, a64, a256, 64, 256);
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}
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return s.join('');
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};
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return obj;
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}]);
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