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Inferno-RegMgr-0.1.7
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/ Inferno::RegMgr

NAME

Inferno::RegMgr - Keep connection to OS Inferno's registry(4) and it tasks

VERSION

This document describes Inferno::RegMgr version 0.1.7

SYNOPSIS

    use EV;
    use Inferno::RegMgr;
    use Inferno::RegMgr::TCP;
    use Inferno::RegMgr::Service;
    use Inferno::RegMgr::Lookup;
    use Inferno::RegMgr::Monitor;

    my $conn = Inferno::RegMgr::TCP->new({ host => '127.0.0.1' });
    my $regmgr = Inferno::RegMgr->new( $conn );

    my $srv1 = Inferno::RegMgr::Service->new({
        name => 'srv1',
        attr => \%attr1,
    });
    my $srv2 = Inferno::RegMgr::Service->new({
        name => 'srv2',
        attr => \%attr2,
    });
    $regmgr->attach( $srv1 );
    $regmgr->attach( $srv2 );

    $regmgr->detach( $srv1 );   # some time later

    $regmgr->attach(
        Inferno::RegMgr::Lookup->new({attr=>\%srchattr,cb=>\&srch});
    );

    my $mon  = Inferno::RegMgr::Monitor->new({
        attr   => \%monitorattr,
        cb_add => \&registered,
        cb_del => \&unregistered,
    });
    $regmgr->attach( $mon );

    EV::loop;

DESCRIPTION

Using OS Inferno registry(4) is simple, but in case connection to registry become broken (because of network issues or even registry restart) you have to manually reconnect to registry and restore state (register your services once again, find out changes in services you're using now, etc.). Inferno::RegMgr will do this work for you automatically.

Inferno::RegMgr has plugin-based architecture. There two plugin types: connection (which handle I/O to registry server) and task (like registering your service or searching for services).

 Connection plugins:
    Inferno::RegMgr::TCP
 Task plugins:
    Inferno::RegMgr::Service
    Inferno::RegMgr::Lookup
    Inferno::RegMgr::Monitor

When you creating new Inferno::RegMgr object, you should provide connection plugin, which will be used to access registry. Next you can attach/detach to this Inferno::RegMgr object any amount of any task plugins. Inferno::RegMgr will guarantee all these tasks will work when connection to registry is available, and task's state will be automatically restored after reconnecting to registry server.

This is EV-based module, so you have to run EV::loop in your code to use this module.

INTERFACE

new( $connection_plugin )

Create new Inferno::RegMgr object, configured to use $connection_plugin to access registry. (All task plugins attached to this object also will use that connection plugin.)

If you lose all references to returned Inferno::RegMgr object all attached tasks will be stopped and detached, all memory used by all plugins will be freed (unless you will keep references to some plugins).

Return Inferno::RegMgr object.

attach( $task_plugin )

Attached plugin will start working as soon as connection to registry will be available. Reference to this plugin will be stored in Inferno::RegMgr object until that plugin will be detach()ed.

You need to keep reference to attached task plugin only if you wanna stop (detach()) it later or if that plugin object provide additional features.

Return nothing.

detach( $task_plugin )

Given $task_plugin should be same as used in attach() method before. It will be stopped and detached (but it still may keep some state, which will may be reused if that plugin will be attach()ed again).

Return nothing.

FOR PLUGIN DEVELOPERS

CONNECTION PLUGIN INTERFACE

open_new()
update()
open_find()
open_event()

These methods must be provided by connection plugin. Their parameters and return values listed at Inferno::RegMgr::TCP.

TASK PLUGIN INTERFACE

{manager}

This property will be set in plugin object to reference to Inferno::RegMgr object in attach(), and will be set to undef in detach(). Plugin should use it to access Inferno::RegMgr object it attached to.

Usually plugin need Inferno::RegMgr object to access it property {registry}, which contain reference to connection plugin object used to access registry. Another uses of Inferno::RegMgr object from task plugin is to detach() itself or attach() another task plugins.

START()
STOP()
REFRESH()

These methods must be provided by task plugin. Their doesn't has parameters and doesn't return anything. Inferno::RegMgr will call START() when connection to registry become available, STOP() when connection to registry lost, and REFRESH() when registry state changes (new service registered, server change it attributes, service unregistered).

DIAGNOSTICS

already attached

You're trying to attach() object which is already attached to this or another Inferno::RegMgr object.

not attached to this manager

You're trying to detach() object which isn't attached to this Inferno::RegMgr object.

CONFIGURATION AND ENVIRONMENT

Inferno::RegMgr requires no configuration files or environment variables.

DEPENDENCIES

 IO::Stream
 EV

INCOMPATIBILITIES

None reported.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests to bug-regmgr@rt.cpan.org, or through the web interface at http://rt.cpan.org.

AUTHOR

Alex Efros <powerman-asdf@ya.ru>

LICENSE AND COPYRIGHT

Copyright (c) 2009, Alex Efros <powerman-asdf@ya.ru>. All rights reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.

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.