POE::Component::SimpleUser3Contributed Perl DocumePOE::Component::SimpleLog(3)NAMEPOE::Component::SimpleLog - Perl extension to manage a simple logging
system for POE.
SYNOPSIS
use POE;
use POE::Component::SimpleLog;
# We don't want Time::HiRes
POE::Component::SimpleLog->new(
ALIAS => 'MyLog',
PRECISION => undef,
) or die 'Unable to create the Logger';
# Create our own session to communicate with SimpleLog
POE::Session->create(
inline_states => {
_start => sub {
# Register for various logs
$_[KERNEL]->post( 'MyLog', 'REGISTER',
LOGNAME => 'FOO',
SESSION => $_[SESSION],
EVENT => 'GotFOOlog',
);
$_[KERNEL]->post( 'MyLog', 'REGISTER',
LOGNAME => 'BAZ',
SESSION => $_[SESSION],
EVENT => 'GotBAZlog',
);
# Log something!
$_[KERNEL]->post( 'MyLog', 'LOG', 'FOO', 'Wow, what a FOO!' );
# This will be silently discarded -> nobody registered for it
$_[KERNEL]->post( 'MyLog', 'LOG', 'BOO', 'Wow, what a BAZ!' );
# OK, enough logging!
$_[KERNEL]->post( 'MyLog', 'UNREGISTER',
LOGNAME => 'FOO',
SESSION => $_[SESSION],
EVENT => 'GotFOOlog',
);
# Now, this log will go nowhere as we just unregistered for it
$_[KERNEL]->post( 'MyLog', 'LOG', 'FOO', 'Wow, what a FOO!' );
# Completely remove all registrations!
$_[KERNEL]->post( 'MyLog', 'UNREGISTERSESSION', $_[SESSION] );
# Now, this log will go nowhere as we just removed all logs pertaining to our session
$_[KERNEL]->post( 'MyLog', 'LOG', 'BAZ', 'Wow, what a BAZ!' );
# We want to eat all we can!
$_[KERNEL]->post( 'MyLog', 'REGISTER',
LOGNAME => 'ALL',
SESSION => $_[SESSION],
EVENT => 'GotLOG',
);
# Now, *ANY* log issued to SimpleLog will go to GotLOG
$_[KERNEL]->post( 'MyLog', 'LOG', 'LAF', 'Wow, what a LAF!' );
# We are done!
$_[KERNEL]->post( 'MyLog', 'SHUTDOWN' );
},
'GotFOOlog' => \&gotFOO,
},
);
sub gotFOO {
# Get the arguments
my( $file, $line, $time, $name, $message ) = @_[ ARG0 .. ARG4 ];
# Assumes PRECISION is undef ( regular time() )
print STDERR "$time ${name}-> $file : $line = $message\n";
}
ABSTRACT
Very simple, and flexible logging system tailored for POE.
DESCRIPTION
This module is a vastly simplified logging system that can do nice
stuff. Think of this module as a dispatcher for various logs.
This module *DOES NOT* do anything significant with logs, it simply
routes them to the appropriate place ( Events )
You register a log that you are interested in, by telling SimpleLog the
target session and target event. Once that is done, any log messages
your program generates ( sent to SimpleLog of course ) will be
massaged, then sent to the target session / target event for
processing.
This enables an interesting logging system that can be changed during
runtime and allow pluggable interpretation of messages.
One nifty idea you can do with this is:
Your program generally creates logs with the name of 'DEBUG'. You DCC
Chat your IRC bot, then tell it to show all debug messages to you. All
the irc bot have to do is register itself for all 'DEBUG' messages, and
once you disconnect from the bot, it can unregister itself.
NOTE: There is no pre-determined log levels ( Like Log4j's DEBUG / INFO
/ FATAL / etc ) Arbitrary names can be used, to great effect. Logs with
the names 'CONNECT', 'DB_QUERY', etc can be created.
The standard way to use this module is to do this:
use POE;
use POE::Component::SimpleLog;
POE::Component::SimpleLog->new( ... );
POE::Session->create( ... );
POE::Kernel->run();
Starting SimpleLog
To start SimpleLog, just call it's new method:
POE::Component::SimpleLog->new(
'ALIAS' => 'MyLogger',
'PRECISION' => 1,
);
This method will die on error or return success.
This constructor accepts only 2 options.
"ALIAS"
This will set the alias SimpleLog uses in the POE Kernel. This
will default TO "SimpleLog"
"PRECISION"
If this value is defined, SimpleLog will use Time::HiRes to get the
timestamps.
Events
SimpleLog is so simple, there are only 5 events available.
"REGISTER"
This event accepts 3 arguments:
LOGNAME -> The name of the log to register for
SESSION -> The session where the log will go ( Also accepts Session ID's )
EVENT -> The event that will be called
The act of registering for a log can fail if one of the above values are undefined.
If the LOGNAME eq 'ALL', then that registration will get *ALL* the logs SimpleLog processes
There is no such thing as an "non-existant" log, registration just makes sure that you will get this log *WHEN* it comes.
Events that receive the logs will get these:
ARG0 -> CALLER_FILE
ARG1 -> CALLER_LINE
ARG2 -> Time::HiRes [ gettimeofday ] or time()
ARG3 -> LOGNAME
ARG4 -> Message
Here's an example:
$_[KERNEL]->post( 'SimpleLog', 'REGISTER',
LOGNAME => 'CONNECTION',
SESSION => $_[SESSION],
EVENT => 'GotLOG',
);
This is the subroutine that will get the GotLOG event
sub gotlog {
# Get the arguments
my( $file, $line, $time, $name, $message ) = @_[ ARG0 .. ARG4 ];
# Assumes PRECISION is undef ( regular time() )
print STDERR "$time ${name}-> $file : $line = $message\n";
# PRECISION = true ( Time::HiRes )
print STDERR "$time->[0].$time->[1] ${name}-> $file : $line = $message\n";
}
"UNREGISTER"
This event accepts 3 arguments:
LOGNAME -> The name of the log to unregister for
SESSION -> The session where the log will go ( Also accepts Session ID's )
EVENT -> The event that will be called
Unregistering for a log will fail if the exact 3 arguments were not found in our registry.
The act of unregistering will mean the session/event no longer receives any log messages.
NOTE: There might be some logs still traversing POE's queue...
Here's an example:
$_[KERNEL]->post( 'SimpleLog', 'UNREGISTER',
LOGNAME => 'CONNECTION',
SESSION => $_[SESSION]->ID,
EVENT => 'GotLOG',
);
"UNREGISTERSESSION"
This event accepts 1 argument:
ARG0 -> The session ( Also accepts Session ID's )
This is useful for removing all the registrations for a specific session.
Here's an example:
$_[KERNEL]->post( 'SimpleLog', 'UNREGISTERSESSION', $_[SESSION] );
"LOG"
This event accepts 2 arguments:
ARG0 -> Logname
ARG1 -> Message
This is where SimpleLog does it's work, sending the log to the proper events.
The Logname can be anything, if there is no events registered for it, the message will simply be discarded.
Here's an example:
$_[KERNEL]->post( 'SimpleLog', 'LOG', 'CONNECTION', 'A Client just connected!' );
"SHUTDOWN"
This is the generic SHUTDOWN routine, it will stop all logging.
Here's an example:
$_[KERNEL]->post( 'SimpleLog', 'SHUTDOWN' );
SimpleLog Notes
This module is very picky about capitalization!
All of the options are uppercase, to avoid confusion.
You can enable debugging mode by doing this:
sub POE::Component::SimpleLog::DEBUG () { 1 }
use POE::Component::SimpleLog;
EXPORT
Nothing.
SEE ALSO
POE
AUTHOR
Apocalypse <apocal@cpan.org>
COPYRIGHT AND LICENSE
Copyright 2008 by Apocalypse
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.14.1 2008-06-11 POE::Component::SimpleLog(3)
