NAME

POEx::WorkerPool::Role::WorkerPool::OpenEndedWorker - A role that provides common semantics for open ended Workers

VERSION

version 1.101610

SYNOPSIS

    # Put this use statement prior to any invocations of WorkerPool
    # See MooseX::CompileTime::Traits for more details
    use POEx::WorkerPool::Worker traits => ['POEx::WorkerPool::Role::WorkerPool::OpenEndedWorker'];

DESCRIPTION

The default Worker role provides a great amount of control for set runs of jobs allowing all sorts of statistics to be captured of failed vs. completed jobs, etc. But sometimes, all of that functionality isn't needed when a dumb worker will fit the bill much better. That is what this role provides. It ignores the queue limits, job worker status, and is a truly opened ended worker. It will spin up as soon as _start is called and periodically check the queue for jobs. It will exhaust the queue each check provided it hasn't been halted or told to stop_processing.

PUBLIC_ATTRIBUTES

stop_processing

  is: rw, isa: Bool, default: 0

stop_processing is a flag used to stop periodic processing of the queue

process_queue_interval

  is: ro, isa: Int, default: 1

process_queue_interval defines the interval for queue processing. This value is passed directly to POEs "delay_add" in POE::Kernel method.

PRIVATE_ATTRIBUTES

_in_process_jobs

    is: ro, isa: HashRef[DoesJob], traits: Hash

This is the in process store of jobs for the open ended worker. Jobs are placed into this structure prior to being passed to the Guts component

The following handles are provided:

    {
        _get_in_process => 'get',
        _add_in_process => 'set',
        _del_in_process => 'delete',
    }

PUBLIC_METHODS

enqueue_job

 (DoesJob $job)

enqueue_job is advised to bypass the queue checks to allow an open ended worker queue.

This method fires +PXWP_JOB_ENQUEUED to the associated PubSub component on success.

Subscribers will need to have the following signature:

    method handler (SessionID :$worker_id, DoesJob $job ) is Event

enqueue_jobs

 (ArrayRef[DoesJob] $jobs)

enqueue_jobs does the same thing as enqueue_job, but it acts on an array of jobs. Each job successfully enqueued means the worker will fire the +PXWP_JOB_ENQUEUED event via PubSub.

halt

 is Event

halt is advised to stop periodic processing

PROTECTED_METHODS

after _start

 is Event

_start is advised to start the prcessing queue using the "process_queue_interval"

guts_output

 (JobStatus $job_status) is Event

This is the StdoutEvent for the child POE::Wheel::Run. It handles all of the child output which is in the form of JobStatus hashrefs. The following describes the potential events from the child and the actions taken

+PXWP_JOB_COMPLETE

    Action: 
        _in_process is cleared.
    
    PubSub Event:
        +PXWP_JOB_COMPLETE
    
    PubSub Signature:
        method handler(SessionID :$worker_id, DoesJob :$job, Ref :$msg)

    Notes:
        The :$msg argument will contain the output from the Job's execution

+PXWP_JOB_PROGRESS

    Action: 
        PubSub event posted.
    
    PubSub Event:
        +PXWP_JOB_PROGRESS
    
    PubSub Signature:
        method handler
        (
            SessionID :$worker_id, 
            DoesJob :$job, 
            Int :$percent_complete,
            Ref :$msg,
        )

    Notes:
        The :$msg argument will contain the output from the last step executed
        for multi-step jobs

+PXWP_JOB_FAILED

    Action: 
        _in_process is cleared.
    
    PubSub Event:
        +PXWP_JOB_FAILED
    
    PubSub Signature:
        method handler(SessionID :$worker_id, DoesJob :$job, Ref :$msg)

    Notes:
        The :$msg argument will contain the exception generated from the Job

+PXWP_JOB_START

    Action: 
        PubSub event posted.
    
    PubSub Event:
        +PXWP_JOB_START
    
    PubSub Signature:
        method handler
        (
            SessionID :$worker_id, 
            DoesJob :$job, 
        )

    Notes:
        This is an indication that the child process received the Job and is
        beginning execution.

PRIVATE_METHODS

_process_queue

 is Event

This private event is the queue processor. As jobs are dequeued for processing, +PXWP_JOB_DEQUEUED will be fired via PubSub. Subscribers will need the following signature:

    method handler(SessionID :$worker_id, DoesJob :$job) is Event

Once this method is called, it will exhaust the current queue and set itself up to be called again on an interval of one second. The interval is configurable via the "process_queue_interval"

_process_job

 (DoesJob $job) is Event

This private event is advised to store the in-process jobs into a separate data structure (since multiple are in flight at once) before being processed. If the child process doesn't exist for whatever reason, +PXWP_WORKER_INTERNAL_ERROR will be fired via PubSub. Subscribers need the following signature:

    method handler(SessionID :$worker_id, Ref :$msg)

In process jobs can be accessed by ID in the "_in_process_jobs" attribute.

AUTHOR

  Nicholas R. Perez <nperez@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2010 by Infinity Interactive.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

cpanm POEx::WorkerPool

perl -MCPAN -e shell
install POEx::WorkerPool