NAME

OP::Log - Circular message sink wrapper

DESCRIPTION

Create and access message sinks on the fly. By default, message sinks are circular OP::RRNode tables.

This class may be used directly, or subclassed for a specific application.

INHERITANCE

This class inherits additional class and object methods from the following packages:

OP::Class > OP::Object > OP::Hash > OP::Node > OP::Log

Circular table classes are derived from OP::RRNode.

SYNOPSIS

First, the log needs to be defined in MySQL as a writable datasource:

  use strict;
  use warnings;

  use OP::Log;

  sub createLog {
    my $log = OP::Log->spawn("Alex's Log");

    $log->setNumRows(10);

    $log->save();
  }

  createLog();

Callers may then write to it:

  use strict;
  use warnings;

  use OP::Log;

  my $log = OP::Log->spawn("Alex's Log");

  $log->write("Writing something");

...or record numeric values:

  my $log = OP::Log->spawn("Ben's Log");

  $log->record(432.234);

If more control is needed when saving messages, full object access is available:

  ...

  use OP::Log;

  my $log = OP::Log->spawn("Alex's Log");

  my $message = $log->newMessage();

  $message->setMessage("Testing at " . scalar(localtime()));
  $message->setState( OP::Enum::State::Crit );
  $message->setValue($$);
  $message->setTimestamp(time());

  $message->save();

The instance method messageClass() returns a OP::RRNode subclass, a handle for the actual stored messages.

  ...

  my $log = OP::Log->spawn( ... );

  #
  # messageClass() returns the message sink table:
  #
  my $table = $log->messageClass();

  for my $id ( $table->allIds() ) {
    my $message = $table->load($id);

    $message->print();
  }

Time Series Data

Time series data is directly available through the series() instance method. This method returns an OP::Series object.

  ...

  my $log = OP::Log->spawn( ... );

  #
  # Get interpolated time series data, ie { unixtime => value, ... }
  #
  my $series = $log->series($start,$end);

  my $data = $series->cooked();

  $data->each( sub {
    print "At unix time $_, the value was $series->{$_}.\n";
  } );

SEE ALSO

This file is part of OP.

REVISION

$Id: //depotit/tools/source/snitchd-0.20/lib/OP/Log.pm#7 $