JobSource

JobSource is an ancestor to factories producing Jobs bound to a given Application and all having some common nature, for instance:

• Queue
• WebService
• DbServicePg

Basically, this is a collection of event handers and other options that are set to a job at the moment of creation.

Constructor

This class is considered abstract parent, so the constructor should be only called through super:

super (app, options)

Parameters

Name	Description
app	an Application instance.
options	a bag of options (see below)

Options

Name	Type	Default	Description
name	String		The unique name with which this JobSource is registered in the hosting Application
globals	Object	{}	an object of properties to be injected in each new job as is. For function valued properies, this works like using mixins.
generators	Object	{}	an object of functions to calculate properties (called without any parameters) injected in each new job
on	Object	{}	a bag of event handlers
rq	Object	{}	request parameters, common to all jobs produced
lag	Number or Array or Lag	0	The minimum time between the constructor call and the finished event
maxLatency	Number	Infinity	the maximum time between since the job creation to the end or error event
maxPending	Number	Infinity	the maximum number of jobs pending in parallel

Properties

Name	Type	Description
app	Application	the constructor's first parameter.
capacity	Number	computed as maxPending - pending.size: the number of jobs allowed to be created at once
lag	Number or Lag	copy of the lag constructor option
maxLatency	Number	copy of the maxLatency constructor option
maxPending	Number	copy of the maxPending constructor option
generators	Map	generated from the generators constructor option
globals	Map	generated from the globals constructor option
pending	Set	Jobs created so far, but not yet finished.
rq	Object	copy of the rq constructor option

Methods

addHandler (event, handler)

Adds an event handler to an internal collection.

Parameters

Name	Description
event	a String, one of Job's event names.
handler	a job => {...} function to be set as handler

createJob (rq = {})

If maxPending is exhausted by pending.size, throws a JobSource.OverflowError. If the numeric value of lag is infinite (which normally means that the Lag instance observed the maximum consecutive errors allowed), throws a JobSource.LockedError.

Otherwise, creates a new Job by the means of this.app, applies all the local options, sets the .src back reference and returns it as a result.

this.rq content is prepended to the rq value.

reset ()

Emits the reset event. Makes sense to notify lag if it's a Lag instance.

Static members

Name	Description
JobSource.LockedError	the class of error thrown when lag is infinite
JobSource.OverflowError	the class of error thrown when maxPending is exhausted

Events

Name	When emitted	Payload
job-start	When a new job emits start	The job
job-end	When a job emits end	The job
job-error	When a job emits error	The job
job-finish	When a job emits finish	The job
job-finished	When a job emits finished	The job
reset	When reset () is called