64 lines
1.3 KiB
JavaScript
64 lines
1.3 KiB
JavaScript
var _ = require('lodash');
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var $ = require('preconditions').singleton();
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function Lock() {
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this.tasks = {};
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};
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Lock.prototype._release = function(token, task) {
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if (!task.running) return;
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task.running = false;
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this.tasks[token] = _.without(this.tasks[token], task);
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this._runOne(token);
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};
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Lock.prototype._runOne = function(token) {
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var self = this;
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if (_.any(self.tasks[token], {
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running: true
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})) return;
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var task = _.first(self.tasks[token]);
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if (!task) return;
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task.running = true;
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if (task.timeout > 0) {
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setTimeout(function() {
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self._release(token, task);
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}, task.timeout);
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}
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task.fn(null, function() {
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self._release(token, task);
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});
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};
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Lock.prototype.locked = function(token, wait, max, userTask) {
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var self = this;
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if (_.isUndefined(self.tasks[token])) {
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self.tasks[token] = [];
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}
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var task = {
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timeout: max,
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running: false,
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fn: userTask,
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};
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self.tasks[token].push(task);
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if (wait > 0) {
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setTimeout(function() {
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if (task.running || !_.contains(self.tasks[token], task)) return;
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self.tasks[token] = _.without(self.tasks[token], task);
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task.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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