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.