95 lines
2.4 KiB
JavaScript
95 lines
2.4 KiB
JavaScript
const fastq = require('fastq');
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const later = require('@breejs/later');
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const pWaitFor = require('p-wait-for');
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const isCronExpression = require('./is-cron-expression');
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const worker = async (task, callback) => {
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try {
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let result = await task();
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callback(null, result);
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} catch (error) {
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callback(error);
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}
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};
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const handler = (error, result) => {
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if (error) {
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throw error;
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}
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// Can potentially standardise the result here
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return result;
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};
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class JobManager {
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constructor(logging) {
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this.queue = fastq(this, worker, 1);
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this.schedule = [];
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this.logging = logging;
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}
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/**
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* Adds job to queue
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*
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* @param {Function} job - function to be executed in the queue
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* @param {Object} [data] - data to be passed into the job
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*/
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addJob(job, data) {
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this.logging.info('Adding one off job to the queue');
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this.queue.push(async () => {
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await job(data);
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}, handler);
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}
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/**
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* Schedules recuring job
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*
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* @param {Function|String} job - function or path to a file defining a job
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* @param {Object} data - data to be passed into the joba
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* @param {String} when - cron or human readable schedule format
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*/
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scheduleJob(job, data, when) {
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let schedule;
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schedule = later.parse.text(when);
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if (isCronExpression(when)) {
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schedule = later.parse.cron(when);
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}
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if ((schedule.error && schedule.error !== -1) || schedule.schedules.length === 0) {
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throw new Error('Invalid schedule format');
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}
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this.logging.info(`Scheduling job. Next run on: ${later.schedule(schedule).next()}`);
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const cancelInterval = later.setInterval(() => {
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this.logging.info(`Scheduled job added to the queue.`);
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this.addJob(job, data);
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}, schedule);
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this.schedule.push(cancelInterval);
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}
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/**
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* @param {import('p-wait-for').Options} [options]
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*/
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async shutdown(options) {
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this.schedule.forEach((cancelHandle) => {
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cancelHandle.clear();
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});
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if (this.queue.idle()) {
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return;
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}
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this.logging.warn('Waiting for busy job queue');
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await pWaitFor(() => this.queue.idle() === true, options);
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this.logging.warn('Job queue finished');
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}
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}
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module.exports = JobManager;
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