path: root/lib/Log/Log4perl/Level.pm

###############r###################################
package Log::Log4perl::Level;
##################################################

use 5.006;
use strict;
use warnings;
use Carp;

# log4j, for whatever reason, puts 0 as all and MAXINT as OFF.
# this seems less optimal, as more logging would imply a higher
# level. But oh well. Probably some brokenness that has persisted. :)
use constant ALL_INT   => 0;
use constant TRACE_INT =>  5000;
use constant DEBUG_INT => 10000;
use constant INFO_INT  => 20000;
use constant WARN_INT  => 30000;
use constant ERROR_INT => 40000;
use constant FATAL_INT => 50000;
use constant OFF_INT   => (2 ** 31) - 1;

no strict qw(refs);
use vars qw(%PRIORITY %LEVELS %SYSLOG %L4P_TO_LD);

%PRIORITY = (); # unless (%PRIORITY);
%LEVELS = () unless (%LEVELS);
%SYSLOG = () unless (%SYSLOG);
%L4P_TO_LD = () unless (%L4P_TO_LD);

sub add_priority {
  my ($prio, $intval, $syslog, $log_dispatch_level) = @_;
  $prio = uc($prio); # just in case;

  $PRIORITY{$prio}    = $intval;
  $LEVELS{$intval}    = $prio;

  # Set up the mapping between Log4perl integer levels and 
  # Log::Dispatch levels
  # Note: Log::Dispatch uses the following levels:
  # 0 debug
  # 1 info
  # 2 notice
  # 3 warning
  # 4 error
  # 5 critical
  # 6 alert
  # 7 emergency

      # The equivalent Log::Dispatch level is optional, set it to 
      # the highest value (7=emerg) if it's not provided.
  $log_dispatch_level = 7 unless defined $log_dispatch_level;
  
  $L4P_TO_LD{$prio}  = $log_dispatch_level;

  $SYSLOG{$prio}      = $syslog if defined($syslog);
}

# create the basic priorities
add_priority("OFF",   OFF_INT,   -1, 7);
add_priority("FATAL", FATAL_INT,  0, 7);
add_priority("ERROR", ERROR_INT,  3, 4);
add_priority("WARN",  WARN_INT,   4, 3);
add_priority("INFO",  INFO_INT,   6, 1);
add_priority("DEBUG", DEBUG_INT,  7, 0);
add_priority("TRACE", TRACE_INT,  8, 0);
add_priority("ALL",   ALL_INT,    8, 0);

# we often sort numerically, so a helper func for readability
sub numerically {$a <=> $b}

###########################################
sub import {
###########################################
    my($class, $namespace) = @_;
           
    if(defined $namespace) {
        # Export $OFF, $FATAL, $ERROR etc. to
        # the given namespace
        $namespace .= "::" unless $namespace =~ /::$/;
    } else {
        # Export $OFF, $FATAL, $ERROR etc. to
        # the caller's namespace
        $namespace = caller(0) . "::";
    }

    for my $key (keys %PRIORITY) {
        my $name  = "$namespace$key";
        my $value = $PRIORITY{$key};
        *{"$name"} = \$value;
	my $nameint = "$namespace${key}_INT";
	my $func = uc($key) . "_INT";
	*{"$nameint"} = \&$func;
    }
}

##################################################
sub new { 
##################################################
    # We don't need any of this class nonsense
    # in Perl, because we won't allow subclassing
    # from this. We're optimizing for raw speed.
}

##################################################
sub to_priority {
# changes a level name string to a priority numeric
##################################################
    my($string) = @_;

    if(exists $PRIORITY{$string}) {
        return $PRIORITY{$string};
    }else{
        croak "level '$string' is not a valid error level (".join ('|', keys %PRIORITY),')';
    }
}

##################################################
sub to_level {
# changes a priority numeric constant to a level name string 
##################################################
    my ($priority) = @_;
    if (exists $LEVELS{$priority}) {
        return $LEVELS{$priority}
    }else {
      croak("priority '$priority' is not a valid error level number (",
	  join("|", sort numerically keys %LEVELS), "
          )");
    }

}

##################################################
sub to_LogDispatch_string {
# translates into strings that Log::Dispatch recognizes
##################################################
    my($priority) = @_;

    confess "do what? no priority?" unless defined $priority;

    my $string;

    if(exists $LEVELS{$priority}) {
        $string = $LEVELS{$priority};
    }

        # Log::Dispatch idiosyncrasies
    if($priority == $PRIORITY{WARN}) {
        $string = "WARNING";
    }
         
    if($priority == $PRIORITY{FATAL}) {
        $string = "EMERGENCY";
    }
         
    return $string;
}

###################################################
sub is_valid {
###################################################
    my $q = shift;

    if ($q =~ /[A-Z]/) {
        return exists $PRIORITY{$q};
    }else{
        return $LEVELS{$q};
    }
    
}

sub get_higher_level {
    my ($old_priority, $delta) = @_;

    $delta ||= 1;

    my $new_priority = 0;

    foreach (1..$delta){
        #so the list is TRACE, DEBUG, INFO, WARN, ERROR, FATAL
      # but remember, the numbers go in reverse order!
        foreach my $p (sort numerically keys %LEVELS){
            if ($p > $old_priority) {
                $new_priority = $p;
                last;
            }
        }
        $old_priority = $new_priority;
    }
    return $new_priority;
}

sub get_lower_level {
    my ($old_priority, $delta) = @_;

    $delta ||= 1;

    my $new_priority = 0;

    foreach (1..$delta){
        #so the list is FATAL, ERROR, WARN, INFO, DEBUG, TRACE
      # but remember, the numbers go in reverse order!
        foreach my $p (reverse sort numerically keys %LEVELS){
            if ($p < $old_priority) {
                $new_priority = $p;
                last;
            }
        }
        $old_priority = $new_priority;
    }
    return $new_priority;
}

sub isGreaterOrEqual {
  my $lval = shift;
  my $rval = shift;
  
  # in theory, we should check if the above really ARE valid levels.
  # but we just use numeric comparison, since they aren't really classes.

  # oh, yeah, and 'cuz level ints go from 0 .. N with 0 being highest,
  # these are reversed.
  return $lval <= $rval;
}

######################################################################
# 
# since the integer representation of levels is reversed from what
# we normally want, we don't want to use < and >... instead, we
# want to use this comparison function


1;

__END__

=encoding utf8

=head1 NAME

Log::Log4perl::Level - Predefined log levels

=head1 SYNOPSIS

  use Log::Log4perl::Level;
  print $ERROR, "\n";

  # -- or --

  use Log::Log4perl qw(:levels);
  print $ERROR, "\n";

=head1 DESCRIPTION

C<Log::Log4perl::Level> simply exports a predefined set of I<Log4perl> log
levels into the caller's name space. It is used internally by 
C<Log::Log4perl>. The following scalars are defined:

    $OFF
    $FATAL
    $ERROR
    $WARN
    $INFO
    $DEBUG
    $TRACE
    $ALL

C<Log::Log4perl> also exports these constants into the caller's namespace
if you pull it in providing the C<:levels> tag:

    use Log::Log4perl qw(:levels);

This is the preferred way, there's usually no need to call 
C<Log::Log4perl::Level> explicitly.

The numerical values assigned to these constants are purely virtual,
only used by Log::Log4perl internally and can change at any time,
so please don't make any assumptions. You can test for numerical equality
by directly comparing two level values, that's ok:

    if( get_logger()->level() == $DEBUG ) {
        print "The logger's level is DEBUG\n";
    }

But if you want to figure out which of two levels is more verbose, use
Log4perl's own comparator:

    if( Log::Log4perl::Level::isGreaterOrEqual( $level1, $level2 ) ) {
        print Log::Log4perl::Level::to_level( $level1 ), 
            " is equal or more verbose than ", 
            Log::Log4perl::Level::to_level( $level2 ), "\n";
    }

If the caller wants to import level constants into a different namespace,
it can be provided with the C<use> command:

    use Log::Log4perl::Level qw(MyNameSpace);

After this C<$MyNameSpace::ERROR>, C<$MyNameSpace::INFO> etc. 
will be defined accordingly.

=head2 Numeric levels and Strings

Level variables like $DEBUG or $WARN have numeric values that are 
internal to Log4perl. Transform them to strings that can be used
in a Log4perl configuration file, use the c<to_level()> function
provided by Log::Log4perl::Level:

    use Log::Log4perl qw(:easy);
    use Log::Log4perl::Level;

        # prints "DEBUG"
    print Log::Log4perl::Level::to_level( $DEBUG ), "\n";

To perform the reverse transformation, which takes a string like
"DEBUG" and converts it into a constant like C<$DEBUG>, use the
to_priority() function:

    use Log::Log4perl qw(:easy);
    use Log::Log4perl::Level;

    my $numval = Log::Log4perl::Level::to_priority( "DEBUG" );

after which $numval could be used where a numerical value is required:

    Log::Log4perl->easy_init( $numval );

=head1 LICENSE

Copyright 2002-2013 by Mike Schilli E<lt>m@perlmeister.comE<gt> 
and Kevin Goess E<lt>cpan@goess.orgE<gt>.

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

=head1 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.