67 lines
1.9 KiB
JavaScript
67 lines
1.9 KiB
JavaScript
/* vim: set expandtab sw=4 ts=4 sts=4: */
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/**
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* phpMyAdmin's BigInts library
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*/
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/**
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* @var BigInts object to handle big integers (in string)
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* as JS can handle upto 53 bits of precision only.
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*/
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var BigInts = {
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/**
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* Compares two integer strings
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*
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* @param int1 the string representation of 1st integer
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* @param int2 the string representation of 2nd integer
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*
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* @return int 0 if equal, < 0 if int1 < int2, else > 0
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*/
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compare: function(int1, int2) {
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// trim integers
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int1 = int1.trim();
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int2 = int2.trim();
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// length of integer strings
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var len1 = int1.length;
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var len2 = int2.length;
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// integer is -ve or not
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var isNeg1 = (int1[0] === '-');
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var isNeg2 = (int2[0] === '-');
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// Sign of int1 != int2 then no actual comparison
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// is needed we can return result directly
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if (isNeg1 !== isNeg2) {
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return (isNeg1 === true ? -1 : 1);
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}
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// replace - sign with 0
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int1[0] = isNeg1 ? '0' : int1[0];
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int2[0] = isNeg2 ? '0' : int2[0];
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// pad integers with 0 to make them
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// equal length
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int1 = BigInts.lpad(int1, len2);
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int2 = BigInts.lpad(int2, len1);
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// Now they are good to compare as strings
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if (int1 !== int2) {
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return (int1 < int2 ? -1 : 1);
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}
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return 0;
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},
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/**
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* Adds leading zeros to a integer given a total length
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*
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* @param int the string representation of the integer
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* @param total the total length required
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*
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* @return int the integer of length given with added leading
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* zeros if necessary
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*/
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lpad: function(int, total){
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var len = int.length;
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var pad = '';
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while(len < total) {
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pad += '0';
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len++;
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}
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return (pad + int);
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}
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};
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