57 lines
1.1 KiB
JavaScript
57 lines
1.1 KiB
JavaScript
var _ = require('lodash');
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var $ = require('preconditions').singleton();
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var locks = {};
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function Lock() {
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};
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Lock.prototype._runOne = function(token) {
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var self = this;
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var item = _.first(locks[token]);
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if (!item || item.started) return;
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item.started = true;
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if (item.maxRunningTime > 0) {
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setTimeout(function() {
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var it = _.first(locks[token]);
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if (it != item) return;
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locks[token].shift();
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self._runOne(token);
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}, item.maxRunningTime);
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}
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item.fn(null, function() {
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locks[token].shift();
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self._runOne(token);
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});
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};
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Lock.prototype.locked = function(token, wait, max, task) {
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var self = this;
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if (_.isUndefined(locks[token])) {
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locks[token] = [];
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}
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var item = {
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maxRunningTime: max,
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started: false,
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fn: task,
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};
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locks[token].push(item);
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if (wait > 0) {
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setTimeout(function() {
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var it = _.find(locks[token], item);
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if (!it || it.started) return;
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locks[token] = _.without(locks[token], it);
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it.fn(new Error('Could not acquire lock ' + token));
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}, wait);
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}
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self._runOne(token);
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};
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module.exports = Lock;
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