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McBain-WithZeroMQ-2.000000
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/ McBain::WithZeroMQ

NAME

McBain::WithZeroMQ - Load a McBain API as a ZeroMQ service

SYNOPSIS

        # write your API as you normally would, and create
        # a simple start-up script:

        #!/usr/bin/perl -w

        use warnings;
        use strict;
        use MyAPI -withZeroMQ;

        MyAPI->work('localhost', 5560);

DESCRIPTION

McBain::WithZeroMQ turns your McBain API into a ZeroMQ REP worker, making it easy to consume your APIs with ZMQ REQ clients. The generated worker code is based on the request-reply worker example in the ZeroMQ guide. Note that the ZeroMQ request-reply pattern requires a broker. The guide also has examples for a broker and a client, though two scripts based on these examples are also provided with this module - more for example than actual usage - see mcbain-zmq-broker and mcbain-zmq-client, respectively.

The workers created by this module receive payloads in JSON format, and convert them into the hash-refs your API's methods expect to receive. The payload must have a path key, which holds the complete path of the route/method to invoke (for example, GET:/math/sum). Results are sent back to the clients in JSON as well. Note that if an API method does not return a hash-ref, this runner module will automatically turn it into a hash-ref to ensure that conversion into JSON will be possible. The created hash-ref will have one key - holding the method's name, with whatever was returned from the method as its value. For example, if method GET:/divide in topic /math returns an integer (say 7), then the client will get the JSON { "GET:/math/divide": 7 }. To avoid, make sure your API's methods return hash-refs.

METHODS EXPORTED TO YOUR API

work( [ $host, $port ] )

Connects the ZeroMQ worker created by the module to the ZeroMQ broker listening at the host and port provided. If none are provided, localhost and 5560 are used, respectively.

The method never returns, so that the worker listens for jobs continuously.

METHODS REQUIRED BY MCBAIN

This runner module implements the following methods required by McBain:

init( )

Creates the "work( $host, $port )" method for the root topic of the API.

generate_env( $job )

Receives the JSON payload and generates McBain's standard env hash-ref from it.

generate_res( $env, $res )

Converts the result from an API method in JSON. Read the discussion under "DESCRIPTION" for more info.

handle_exception( $err )

Simply calls $job->send_fail to return a job failed status to the client.

CONFIGURATION AND ENVIRONMENT

No configuration files are required.

DEPENDENCIES

McBain::WithZeroMQ depends on the following CPAN modules:

INCOMPATIBILITIES WITH OTHER MODULES

None reported.

BUGS AND LIMITATIONS

Please report any bugs or feature requests to bug-McBain-WithZeroMQ@rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=McBain-WithZeroMQ.

SUPPORT

You can find documentation for this module with the perldoc command.

        perldoc McBain::WithZeroMQ

You can also look for information at:

AUTHOR

Ido Perlmuter <ido@ido50.net>

SEE ALSO

McBain

LICENSE AND COPYRIGHT

Copyright (c) 2014, Ido Perlmuter ido@ido50.net.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either version 5.8.1 or any later version. See perlartistic and perlgpl.

The full text of the license can be found in the LICENSE file included with this module.

DISCLAIMER OF WARRANTY

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.