NAME
McBain::WithGearmanXS - Load a McBain API as a Gearman worker
VERSION
version 1.000000
SYNOPSIS
# write your API as you normally would, and create
# a simple start-up script:
#!/usr/bin/perl -w
BEGIN { $ENV{MCBAIN_WITH} = 'WithGearmanXS'; }
use warnings;
use strict;
use MyAPI;
MyAPI->work('localhost', 4730);
DESCRIPTION
"McBain::WithGearmanXS" turns your McBain API into a Gearman worker,
making it easy to consume your APIs with Gearman clients.
When your API is loaded, this module will traverse its routes, and
create a queue for each methods found. So, for example, if your API
looks like this...
package MyAPI;
use McBain;
get '/multiply' => (
...
);
post '/divide' => (
...
);
...then the following queues will be created:
GET:/multiply
POST:/divide
The workers created receive payloads in JSON format, and convert them
into the hash-refs your API's methods expect to receive. 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 }".
CAVEATS
There are some disadvantages to using this runner:
* Since a queue is created for every route and method in the API,
"McBain" cannot intercept calls to routes that do not exist.
* You can't use regular expressions when defining queues. Well, you
can, but they won't work.
* Gearman provides no way of providing a detailed error message when
jobs fail, therefore all "McBain" can do is indicate that the job
has failed and no more.
The first two I hope to overcome in a next version, or even a different
runner, by creating just one queue that simply forwards the requests to
"McBain".
METHODS EXPORTED TO YOUR API
work( [ $host, $port ] )
Connects the Gearman worker created by the module to the Gearman server
running at the host and port provided. If none are provided, "localhost"
and 4730 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 Gearman::XS::Job object and creates "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, $job )
Simply calls "$job->send_fail" to return a job failed status to the
client.
CONFIGURATION AND ENVIRONMENT
No configuration files are required. To tell McBain to use this runner
module, the "MCBAIN_WITH" environment variable must be set to
"WithGearmanXS". See the "SYNOPSIS" for an example.
DEPENDENCIES
"McBain::WithGearmanXS" depends on the following CPAN modules:
* Carp
* Gearman::XS
* JSON
INCOMPATIBILITIES WITH OTHER MODULES
None reported.
BUGS AND LIMITATIONS
Please report any bugs or feature requests to
"
[email protected]", or through the web interface at
<
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=McBain-WithGearmanXS>.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc McBain::WithGearmanXS
You can also look for information at:
* RT: CPAN's request tracker
<
http://rt.cpan.org/NoAuth/Bugs.html?Dist=McBain-WithGearmanXS>
* AnnoCPAN: Annotated CPAN documentation
<
http://annocpan.org/dist/McBain-WithGearmanXS>
* CPAN Ratings
<
http://cpanratings.perl.org/d/McBain-WithGearmanXS>
* Search CPAN
<
http://search.cpan.org/dist/McBain-WithGearmanXS/>
AUTHOR
Ido Perlmuter <
[email protected]>
LICENSE AND COPYRIGHT
Copyright (c) 2013, Ido Perlmuter "
[email protected]".
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.
