Paranoid::Log::Buffer - Log Buffer Functions

Paranoid documentation Contained in the Paranoid distribution.

Index

Code Index:

NAME

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Paranoid::Log::Buffer - Log Buffer Functions

VERSION

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$Id: Buffer.pm,v 0.83 2010/06/03 19:03:46 acorliss Exp $

SYNOPSIS

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  use Paranoid::Log;

  enableFacility('events', 'buffer', 'debug', '+');
  enableFacility('more-events', 'buffer', 'debug', '+', 100);

  @messages = Paranoid::Log::Buffer::dump($name);

DESCRIPTION

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This module implements named buffers to be used for logging purposes. Each buffer is of a concrete size (definable by the developer) with a max message length of 2KB. Each message is stored with a timestamp. Once the buffer hits the maximun number of entries it begins deleting the oldest messages as the new messages come in.

Buffers are created automatically on the fly, and messages trimmed before being stored.

With the exception of the dump function this module is not meant to be used directly. Paranoid::Log should be your exclusive interface for logging.

When enabling a buffer facility with Paranoid::Log you can add one integral argument to the call. That number defines the size of the log buffer in terms of number of entries allowed.

NOTE: Buffers are maintained within process memory. If you fork a process from a parent with a log buffer each copy will maintain its own entries.

SUBROUTINES/METHODS

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NOTE: Given that this module is not intended to be used directly nothing is exported.

init

log

remove

Paranoid::Log::Buffer::dump

  @entries = Paranoid::Log::Buffer::dump($name);

This dumps all current entries in the named buffer. Each entry is an array reference to a two-element array. The first element is the timestamp of the message (in UNIX epoch seconds), the second the actual message itself.

DEPENDENCIES

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o

Paranoid::Debug

SEE ALSO

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o

Paranoid::Log

BUGS AND LIMITATIONS

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AUTHOR

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Arthur Corliss (corliss@digitalmages.com)

LICENSE AND COPYRIGHT

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This software is licensed under the same terms as Perl, itself. Please see http://dev.perl.org/licenses/ for more information.

(c) 2005, Arthur Corliss (corliss@digitalmages.com)

Paranoid documentation Contained in the Paranoid distribution. 
# Paranoid::Log::Buffer -- Log buffer support for paranoid programs
#
# (c) 2005, Arthur Corliss <corliss@digitalmages.com>
#
# $Id: Buffer.pm,v 0.83 2010/06/03 19:03:46 acorliss Exp $
#
#    This software is licensed under the same terms as Perl, itself.
#    Please see http://dev.perl.org/licenses/ for more information.
#
#####################################################################

#####################################################################
#
# Environment definitions
#
#####################################################################

package Paranoid::Log::Buffer;

use 5.006;

use strict;
use warnings;
use vars qw($VERSION);
use Paranoid::Debug qw(:all);
use Carp;

($VERSION) = ( q$Revision: 0.83 $ =~ /(\d+(?:\.(\d+))+)/sm );

#####################################################################
#
# Module code follows
#
#####################################################################

{

    # Buffers
    my %buffers = ();

    sub _getBuffer ($) {

        # Purpose:  Retrieves the named buffer (which is an array ref).
        #           Creates the array on the fly if it doesn't exist.
        # Returns:  Array ref
        #           False (0) if there are any errors
        # Usage:    $ref = _getBuffer($name);

        my $name = shift;

        $buffers{$name} = [] unless exists $buffers{$name};

        return $buffers{$name};
    }

    sub _delBuffer ($) {

        # Purpose:  Deletes the named buffer from the hash.
        # Returns:  True (1)
        # Usage:    _delBuffer($name);

        my $name = shift;

        delete $buffers{$name} if exists $buffers{$name};

        return 1;
    }

    sub init () {

        # Purpose:  Empties the named buffer hash
        # Returns:  True (1)
        # Usage:    init();

        %buffers = ();

        return 1;
    }

}

sub remove ($) {

    # Purpose:  Removes the requested buffer
    # Returns:  Return value of _delBuffer()
    # Usage:    $rv = remove($name);

    my $name = shift;

    return _delBuffer($name);
}

sub log ($$$$$$$$) {

    # Purpose:  Logs the passed message to the named buffer, trimming excess
    #           messages as needed
    # Returns:  True (1)
    # Usage:    log($msgtime, $severity, $message, $name, $facility, $level,
    #               $scope);
    # Usage:    log($msgtime, $severity, $message, $name, $facility, $level,
    #               $scope, $buffSize);

    my $msgtime  = shift;
    my $severity = shift;
    my $message  = shift;
    my $name     = shift;
    my $facility = shift;
    my $level    = shift;
    my $scope    = shift;
    my $buffSize = shift;
    my $barg     = defined $buffSize ? $buffSize : 'undef';
    my $buffer   = _getBuffer($name);

    # Validate arguments
    croak 'Mandatory third argument must be a valid message'
        unless defined $message;
    croak 'Mandatory fourth argument must be a defined buffer name'
        unless defined $name;

    pdebug(
        "entering w/($msgtime)($severity)($message)($name)($facility)"
            . "($level)($scope)($barg)",
        PDLEVEL1
        );
    pIn();

    # Buffer size defaults to twenty entries
    $buffSize = 20 unless defined $buffSize and $buffSize > 0;

    # Message time defaults to current time
    $msgtime = time unless defined $msgtime;

    # Trim the buffer if needed
    splice( @$buffer, 0, $buffSize - 1 ) if scalar @$buffer > $buffSize;

    # Add the message
    push @$buffer, [ $msgtime, $message ];

    pOut();
    pdebug( 'leaving w/rv: 1', PDLEVEL1 );

    return 1;
}

sub dump ($) {

    # Purpose:  Returns the contents of the named buffer
    # Returns:  Array
    # Usage:    @events = dump($name);

    my $name   = shift;
    my $buffer = _getBuffer($name);

    return @$buffer;
}

1;

__END__