73 lines
2.0 KiB
JavaScript
73 lines
2.0 KiB
JavaScript
'use strict';
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var Channel = require('./channel');
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var QueueSeeker = require('./queue-seeker');
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var debug = require('./../util/debug')('pubsub:subscriber');
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var error = require('./../util/debug')('pubsub:subscriber:error');
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var MINUTE = 60 * 1000;
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var SUBSCRIBE_INTERVAL = 5 * MINUTE;
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function JobSubscriber(pool) {
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this.pool = pool;
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this.queueSeeker = new QueueSeeker(pool);
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}
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module.exports = JobSubscriber;
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function seeker(queueSeeker, onJobHandler, callback) {
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queueSeeker.seek(function (err, hosts) {
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if (err) {
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if (callback) {
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callback(err);
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}
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return error(err);
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}
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debug('queues found successfully');
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hosts.forEach(onJobHandler);
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if (callback) {
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return callback(null);
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}
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});
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}
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JobSubscriber.prototype.subscribe = function (onJobHandler, callback) {
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var self = this;
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this.seekerInterval = setInterval(seeker, SUBSCRIBE_INTERVAL, this.queueSeeker, onJobHandler);
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this.pool.acquire(Channel.DB, function (err, client) {
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if (err) {
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return error('Error adquiring redis client: ' + err.message);
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}
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self.client = client;
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client.removeAllListeners('message');
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client.unsubscribe(Channel.NAME);
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client.subscribe(Channel.NAME);
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client.on('message', function (channel, host) {
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debug('message received from: ' + channel + ':' + host);
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onJobHandler(host);
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});
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client.on('error', function () {
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self.unsubscribe();
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self.pool.release(Channel.DB, client);
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self.subscribe(onJobHandler);
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});
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});
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seeker(this.queueSeeker, onJobHandler, callback);
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};
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JobSubscriber.prototype.unsubscribe = function (callback) {
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clearInterval(this.seekerInterval);
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if (this.client && this.client.connected) {
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this.client.unsubscribe(Channel.NAME, callback);
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} else {
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return callback(null);
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}
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};
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