1 import { AsyncQueue, forever, queue } from 'async'
2 import * as Sequelize from 'sequelize'
4 import { database as db } from '../../initializers/database'
6 JOBS_FETCHING_INTERVAL,
7 JOBS_FETCH_LIMIT_PER_CYCLE,
9 } from '../../initializers'
10 import { logger } from '../../helpers'
11 import { JobInstance } from '../../models'
12 import { JobHandler, jobHandlers } from './handlers'
14 type JobQueueCallback = (err: Error) => void
18 private static instance: JobScheduler
20 private constructor () { }
22 static get Instance () {
23 return this.instance || (this.instance = new this())
27 const limit = JOBS_FETCH_LIMIT_PER_CYCLE
29 logger.info('Jobs scheduler activated.')
31 const jobsQueue = queue<JobInstance, JobQueueCallback>(this.processJob.bind(this))
33 // Finish processing jobs from a previous start
34 const state = JOB_STATES.PROCESSING
36 const jobs = await db.Job.listWithLimit(limit, state)
38 this.enqueueJobs(jobsQueue, jobs)
40 logger.error('Cannot list pending jobs.', err)
45 if (jobsQueue.length() !== 0) {
46 // Finish processing the queue first
47 return setTimeout(next, JOBS_FETCHING_INTERVAL)
50 const state = JOB_STATES.PENDING
52 const jobs = await db.Job.listWithLimit(limit, state)
54 this.enqueueJobs(jobsQueue, jobs)
56 logger.error('Cannot list pending jobs.', err)
59 // Optimization: we could use "drain" from queue object
60 return setTimeout(next, JOBS_FETCHING_INTERVAL)
63 err => logger.error('Error in job scheduler queue.', err)
67 createJob (transaction: Sequelize.Transaction, handlerName: string, handlerInputData: object) {
69 state: JOB_STATES.PENDING,
73 const options = { transaction }
75 return db.Job.create(createQuery, options)
78 private enqueueJobs (jobsQueue: AsyncQueue<JobInstance>, jobs: JobInstance[]) {
79 jobs.forEach(job => jobsQueue.push(job))
82 private async processJob (job: JobInstance, callback: (err: Error) => void) {
83 const jobHandler = jobHandlers[job.handlerName]
84 if (jobHandler === undefined) {
85 logger.error('Unknown job handler for job %s.', job.handlerName)
89 logger.info('Processing job %d with handler %s.', job.id, job.handlerName)
91 job.state = JOB_STATES.PROCESSING
95 const result = await jobHandler.process(job.handlerInputData, job.id)
96 await this.onJobSuccess(jobHandler, job, result)
98 logger.error('Error in job handler %s.', job.handlerName, err)
101 await this.onJobError(jobHandler, job, err)
103 this.cannotSaveJobError(innerErr)
104 return callback(innerErr)
111 private async onJobError (jobHandler: JobHandler<any>, job: JobInstance, err: Error) {
112 job.state = JOB_STATES.ERROR
116 await jobHandler.onError(err, job.id)
118 this.cannotSaveJobError(err)
122 private async onJobSuccess (jobHandler: JobHandler<any>, job: JobInstance, jobResult: any) {
123 job.state = JOB_STATES.SUCCESS
127 jobHandler.onSuccess(job.id, jobResult)
129 this.cannotSaveJobError(err)
133 private cannotSaveJobError (err: Error) {
134 logger.error('Cannot save new job state.', err)
138 // ---------------------------------------------------------------------------