NAME

       Log::Log4perl::Appender::Buffer - Buffering Appender

SYNOPSIS

           use Log::Log4perl qw(:easy);

           my $conf = qq(
           log4perl.category                  = DEBUG, Buffer

               # Regular Screen Appender
           log4perl.appender.Screen           = Log::Log4perl::Appender::Screen
           log4perl.appender.Screen.stdout    = 1
           log4perl.appender.Screen.layout    = PatternLayout
           log4perl.appender.Screen.layout.ConversionPattern = %d %p %c %m %n

               # Buffering appender, using the appender above as outlet
           log4perl.appender.Buffer               = Log::Log4perl::Appender::Buffer
           log4perl.appender.Buffer.appender      = Screen
           log4perl.appender.Buffer.trigger_level = ERROR
           );

           Log::Log4perl->init(\$conf);

           DEBUG("This message gets buffered.");
           INFO("This message gets buffered also.");

           # Time passes. Nothing happens. But then ...

           print "It's GO time!!!\n";

           ERROR("This message triggers a buffer flush.");

DESCRIPTION

       "Log::Log4perl::Appender::Buffer" takes these arguments:

       "appender"
           Specifies  the  name  of the appender it buffers messages for. The appender specified must be defined
           somewhere   in   the   configuration   file,   not   necessarily    before    the    definition    of
           "Log::Log4perl::Appender::Buffer".

       "max_messages"
           Specifies the maximum number of messages the appender will hold in its ring buffer. "max_messages" is
           optional.  By  default,  "Log::Log4perl::Appender::Buffer"  will  not  limit  the  number of messages
           buffered. This might be undesirable in long-running processes accumulating lots of messages before  a
           flush  happens.  If  "max_messages" is set to a numeric value, "Log::Log4perl::Appender::Buffer" will
           displace old messages in its buffer to make room if the buffer is full.

       "trigger_level"
           If trigger_level is set to one of Log4perl's levels (see Log::Log4perl::Level), a "trigger"  function
           will be defined internally to flush the buffer if a message with a priority of $level or higher comes
           along. This is just a convenience function. Defining

               log4perl.appender.Buffer.trigger_level = ERROR

           is equivalent to creating a trigger function like

               log4perl.appender.Buffer.trigger = sub {   \
                   my($self, $params) = @_;               \
                   return $params->{log4p_level} >=       \
                          $Log::Log4perl::Level::ERROR; }

           See the next section for defining generic trigger functions.

       "trigger"
           "trigger"  holds  a  reference  to a subroutine, which "Log::Log4perl::Appender::Buffer" will call on
           every incoming message with the same parameters as the appender's "log()" method:

                   my($self, $params) = @_;

           $params references a hash containing the message priority (key  "l4p_level"),  the  message  category
           (key "l4p_category") and the content of the message (key "message").

           If the subroutine returns 1, it will trigger a flush of buffered messages.

           Shortcut

DEVELOPMENT NOTES

       "Log::Log4perl::Appender::Buffer"  is  a  composite appender.  Unlike other appenders, it doesn't log any
       messages, it just passes them on to its attached sub-appender.  For this reason, it doesn't need a layout
       (contrary to regular appenders).  If it defines none, messages are passed on unaltered.

       Custom filters are also applied to the composite appender  only.   They  are  not  applied  to  the  sub-
       appender. Same applies to appender thresholds. This behaviour might change in the future.

LICENSE

       Copyright 2002-2013 by Mike Schilli <m@perlmeister.com> and Kevin Goess <cpan@goess.org>.

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

AUTHOR

       Please contribute patches to the project on Github:

           http://github.com/mschilli/log4perl

       Send bug reports or requests for enhancements to the authors via our

       MAILING LIST (questions, bug reports, suggestions/patches): log4perl-devel@lists.sourceforge.net

       Authors (please contact them via the list above, not directly): Mike Schilli  <m@perlmeister.com>,  Kevin
       Goess <cpan@goess.org>

       Contributors  (in  alphabetical  order):  Ateeq  Altaf,  Cory Bennett, Jens Berthold, Jeremy Bopp, Hutton
       Davidson, Chris R. Donnelly, Matisse Enzer, Hugh Esco, Anthony Foiani,  James  FitzGibbon,  Carl  Franks,
       Dennis  Gregorovic,  Andy  Grundman,  Paul  Harrington, Alexander Hartmaier  David Hull, Robert Jacobson,
       Jason Kohles, Jeff Macdonald, Markus Peter, Brett Rann, Peter Rabbitson, Erik Selberg, Aaron Straup Cope,
       Lars Thegler, David Viner, Mac Yang.

perl v5.36.0                                       2022-10-30                              Appender::Buffer(3pm)