35 lines
581 B
JavaScript
35 lines
581 B
JavaScript
var _ = require('lodash');
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var $ = require('preconditions').singleton();
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var locks = {};
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var Lock = function() {
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this.taken = false;
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this.queue = [];
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};
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Lock.prototype.free = function() {
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if (this.queue.length > 0) {
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var f = this.queue.shift();
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f(this);
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} else {
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this.taken = false;
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}
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};
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Lock.get = function(key, callback) {
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if (_.isUndefined(locks[key])) {
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locks[key] = new Lock();
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}
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var lock = locks[key];
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if (lock.taken) {
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lock.queue.push(callback);
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} else {
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lock.taken = true;
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callback(lock);
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}
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};
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module.exports = Lock;
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