61 lines
1.7 KiB
JavaScript
61 lines
1.7 KiB
JavaScript
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function encode(uint8array) {
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var output = [];
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for (var i = 0, length = uint8array.length; i < length; i+=2) {
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if (uint8array.length -i > 1) {
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var x = (uint8array[i]<<8)+ uint8array[i+1]
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var [ e, x ] = divmod(x, 45*45)
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var [ d, c ] = divmod(x, 45)
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output.push(fromCharCode(c) + fromCharCode(d) + fromCharCode(e))
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} else {
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var x = uint8array[i]
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var [ d, c ] = divmod(x, 45)
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output.push(fromCharCode(c) + fromCharCode(d))
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}
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}
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return output.join('')
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};
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var divmod = function divmod(a,b) {
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var remainder = a
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var quotient = 0
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if (a >= b) {
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remainder = a % b
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quotient = (a - remainder) / b
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}
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return [ quotient, remainder ]
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}
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const BASE45_CHARSET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:"
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var fromCharCode = function fromCharCode(c) {
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return BASE45_CHARSET.charAt(c);
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};
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function decode(str) {
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var output = []
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var buf = []
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for(var i = 0, length=str.length; i < length; i++) {
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//console.log(i);
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var j = BASE45_CHARSET.indexOf(str[i])
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if (j < 0)
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console.log('Base45 decode: unknown character n.', i, j);
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//throw new Error('Base45 decode: unknown character');
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buf.push(j)
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}
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for(var i = 0, length=buf.length; i < length; i+=3) {
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var x = buf[i] + buf[i + 1] * 45
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if (length - i >= 3) {
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var [d, c] = divmod(x + buf[i + 2] * 45 * 45,256)
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output.push(d)
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output.push(c)
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} else {
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output.push(x)
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}
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}
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console.log("output",output);
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var enc = new TextEncoder();
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return {"enc" : enc.encode(output), "raw" : output};
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//return Buffer.from(output);
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};
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