47 lines
1.2 KiB
JavaScript
47 lines
1.2 KiB
JavaScript
'use strict';
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var generate = require('./generate');
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var alphabet = require('./alphabet');
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// Ignore all milliseconds before a certain time to reduce the size of the date entropy without sacrificing uniqueness.
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// This number should be updated every year or so to keep the generated id short.
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// To regenerate `new Date() - 0` and bump the version. Always bump the version!
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var REDUCE_TIME = 1567752802062;
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// don't change unless we change the algos or REDUCE_TIME
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// must be an integer and less than 16
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var version = 7;
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// Counter is used when shortid is called multiple times in one second.
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var counter;
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// Remember the last time shortid was called in case counter is needed.
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var previousSeconds;
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/**
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* Generate unique id
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* Returns string id
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*/
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function build(clusterWorkerId) {
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var str = '';
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var seconds = Math.floor((Date.now() - REDUCE_TIME) * 0.001);
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if (seconds === previousSeconds) {
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counter++;
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} else {
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counter = 0;
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previousSeconds = seconds;
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}
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str = str + generate(version);
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str = str + generate(clusterWorkerId);
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if (counter > 0) {
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str = str + generate(counter);
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}
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str = str + generate(seconds);
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return str;
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}
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module.exports = build;
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