Run long-running jobs, one at a time, whilst emitting W3C ProgressEvents
Just inherit from JobSequencer
const JobSequencer = require('job-sequencer')
class LongRunningJobManager extends JobSequencer {
constructor() {
super()
}
async batchProcessFoo() {
let batchJobFoo
try {
// Create a job with name 'batch-process-foo' that will tick
// `job.progress()` 5 times
batchJobFoo = this.createJob('batch-process-foo', 5);
batchJobFoo.start()
batchJobFoo.progress()
batchJobFoo.progress()
batchJobFoo.progress()
batchJobFoo.progress()
batchJobFoo.progress()
batchJobFoo.success({ foo: 'bar' })
} catch (err) {
job.error(err)
}
}
}
const batchProcessor = new LongRunningJobManager()
batchProcessor.on('status', status => {
switch (status.type) {
case 'loadstart':
console.log('started')
break;
case 'progress':
console.log(status.progress) // `{ total: 5, loaded: 2 }`.. etc
break;
case 'load':
console.log(status.payload) // `{ foo: bar }`
break;
case 'error':
console.log(status.payload) // logs any potential error
break;
default:
// do nothing
}
})
batchProcessor.batchProcessFoo()
You can only run one job at a time. If any of the following events are called:
job.success()
job.error()
job.abort()
job.stop()
the Job
is considered finished and it's ejected, thus allowing
other Job
's with the same name to run.
Attempting to run another Job
with the same name if the aforementioned methods
have not been called on Job
will result in an Exception
All events map to W3C Progress Events
Method | W3C ProgressEvent emitted |
---|---|
job.start() |
loadstart |
job.progress() |
progress |
job.error() |
error |
job.abort() |
abort |
job.success() |
load |
job.stop() |
loadend |
npm test
Job Sequencer
✓ it instantiates
when a Job is created
✓ creates a Running Job
✓ returns a Running Job by name if it exists
✓ returns true if a Running Job exists by name
✓ returns a list of all the last statuses emitted by still running, Running Jobs
✓ clears the Running Job if the job has succeeded
✓ clears the Running Job if the job is errored
✓ clears the Running Job if the job is aborted
✓ clears the Running Job if the job is stopped
when attempting to create a Job whilst another is running
✓ throws an exception
✓ creates the Job if the Job is done
✓ creates the Job if the Job is errored
✓ creates the Job if the Job is aborted
✓ creates the Job if the Job is stopped
Job Class
✓ instantiates in the correct state
✓ fires a loadstart event when start is called
✓ fires a progress event when progress is called
✓ fires an error event when error is called
✓ fires an abort event when abort is called
✓ fires a load event when success is called
✓ fires a loadend event when stop is called
✓ increments the loaded count by 1 when a progress event is emitted
✓ includes the job name when emitting an event
✓ includes any payload passed as arg. when emitting an event
✓ returns the last emitted status
Copyright 2017 Nicholas Kyriakides
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