base

# NAME

Smokeping::matchers::base - Base Class for implementing SmokePing Matchers

# OVERVIEW

    This is the base class for writing SmokePing matchers. Every matcher must
    inherit from the base class and provide it's own methods for the 'business'
    logic.

Note that the actual matchers must have at least one capital letter in their name, to differentiate them from the base class(es).

# DESCRIPTION

Every matcher must provide the following methods:

## new

The new method expects hash elements as an argument eg new({x=>'\d+',y=>'\d+'},x=>1,y=>2). The first part is a syntax rule for the arguments it should expect and the second part are the arguments itself. The first part will be supplied by the child class as it calls the parent method.

## Length

The Length method returns the number of values the matcher will expect from SmokePing. This method must be overridden by the children of the base class.

## Desc

Simply return the description of the function. This method must be overwritten by a children of the base class.

## Test

Run the matcher and return true or false. The Test method is called with a hash containing two arrays giving it access to both rtt and loss values.

      my $data=shift;
      my @rtt = @{$data->{rtt}};
      my @loss = @{$data->{loss}};

The arrays are ordered from old to new.

      @rdd[old..new]

There may be more than the expected number of elements in this array. Address them with $x[-1] to $x[-max].

There's also a key called 'prevmatch' in the hash. It contains the value returned by the previous call of the 'Test' method. This allows for somewhat more intelligent alerting due to state awareness.

      my $prevmatch = $data->{prevmatch};

# COPYRIGHT

Copyright (c) 2004 by OETIKER+PARTNER AG. All rights reserved.

# LICENSE

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

# AUTHOR

Tobias Oetiker <tobi@oetiker.ch>