NAME

Data::Range::Compare::Stream::Cookbook::COMPARE_DateTime - DateTime Howto for Data::Range::Compare::Stream

DESCRIPTION

This section covers how to create a compare class that can handle DateTime ranges. So if you are looking for a way to compare date ranges for overlaps this is a great starting point.

Special notes

Comparing DateTime ranges requires having 2 DateTime objects per range: One as the start value and one as the end value.

Implementing a new Data::Range::Compare::Stream class

Example package

package Data::Range::Compare::Stream::DateTime;

use strict;
use warnings;
use DateTime;
use base qw(Data::Range::Compare::Stream);

#
# Define the class internals will use when creating a new object instance(s)
use constant NEW_FROM_CLASS=>'Data::Range::Compare::Stream::DateTime';

sub cmp_values ($$) {
  my ($self,$value_a,$value_b)=@_;
  return DateTime->compare($value_a,$value_b);
}

sub add_one ($) {
  my ($self,$value)=@_;
  return $value->clone->add(seconds=>1);
}

sub sub_one ($) {
  my ($self,$value)=@_;
  return $value->clone->subtract(seconds=>1);
}

sub range_start_to_string {
  my ($self)=@_;
  return $self->range_start->strftime('%F %T');
}

sub range_end_to_string {
  my ($self)=@_;
  return $self->range_end->strftime('%F %T');
}

Putting it all togeather

Now we can use the new Compare package to handle processing our DateTime Ranges

use strict;
use warnings;

use Data::Range::Compare::Stream::Iterator::Array;
use Data::Range::Compare::Stream::Iterator::Consolidate;
use Data::Range::Compare::Stream::Iterator::Compare::Asc;
use Data::Range::Compare::Stream::DateTime;

my $vpn_a=new Data::Range::Compare::Stream::Iterator::Array(new_from=>'Data::Range::Compare::Stream::DateTime');
my $vpn_b=new Data::Range::Compare::Stream::Iterator::Array(new_from=>'Data::Range::Compare::Stream::DateTime');;
my $vpn_c=new Data::Range::Compare::Stream::Iterator::Array(new_from=>'Data::Range::Compare::Stream::DateTime');;

#
# Outage block for vpn_a
$vpn_a->create_range(
   DateTime->new(qw(year 2010 month 01 day 02 hour 10 minute 01 second 59)),
   DateTime->new(qw(year 2010 month 01 day 02 hour 10 minute 05 second 47))
);

$vpn_a->create_range(
   DateTime->new(qw(year 2010 month 05 day 02 hour 07 minute 41 second 32)),
   DateTime->new(qw(year 2010 month 05 day 02 hour 08 minute 00 second 16))
);


#
# Outage block for vpn_b
$vpn_b->create_range(
   DateTime->new(qw(year 2010 month 05 day 02 hour 07 minute 41 second 32)),
   DateTime->new(qw(year 2010 month 05 day 02 hour 07 minute 58 second 13))
);

$vpn_b->create_range(
   DateTime->new(qw(year 2010 month 01 day 02 hour 10 minute 03 second 59)),
   DateTime->new(qw(year 2010 month 01 day 02 hour 10 minute 04 second 37))
);

#
# Outage block for vpn_c
$vpn_c->create_range(
    DateTime->new(qw(year 2010 month 01 day 02 hour 10 minute 03 second 59)),
    DateTime->new(qw(year 2010 month 01 day 02 hour 10 minute  04 second 37))
);

$vpn_c->create_range(
    DateTime->new(qw(year 2010 month 05 day 02 hour 07 minute 41 second 32)),
    DateTime->new(qw(year 2010 month 05 day 02 hour 07 minute 58 second 13))
);

$vpn_c->create_range(
    DateTime->new(qw(year 2010 month 05 day 02 hour 07 minute 59 second 07)),
    DateTime->new(qw(year 2010 month 05 day 02 hour 08 minute 00 second 16))
);

$vpn_c->create_range(
    DateTime->new(qw(year 2010 month 06 day 18 hour 10 minute 58 second 21)),
    DateTime->new(qw(year 2010 month 06 day 18 hour 22 minute 06 second 55))
  );


#
# Make sure our list of vpns are sorted
$vpn_a->prepare_for_consolidate_asc;
$vpn_b->prepare_for_consolidate_asc;
$vpn_c->prepare_for_consolidate_asc;

#
# create our consolidation interface for each Array Iterator
my $column_a=Data::Range::Compare::Stream::Iterator::Consolidate->new($vpn_a);
my $column_b=Data::Range::Compare::Stream::Iterator::Consolidate->new($vpn_b);
my $column_c=Data::Range::Compare::Stream::Iterator::Consolidate->new($vpn_c);

#
# Create our compare object
my $compare=Data::Range::Compare::Stream::Iterator::Compare::Asc->new;

$compare->add_consolidator($column_a);
$compare->add_consolidator($column_b);
$compare->add_consolidator($column_c);

my @column_names=(qw(vpn_a vpn_b vpn_c));

while($compare->has_next) {
  my $row=$compare->get_next;

  # skip all rows that don't complety overlap
  next unless $row->all_overlap;

  my $common=$row->get_common;

  my $outage=$common->range_end->subtract_datetime($common->range_start);
  print "Common outage range: $common\n";
  print "Total Downtime: Months: $outage->{months} Days: $outage->{days} Minutes: $outage->{minutes} Seconds: $outage->{seconds}\n";

  for(my $id=0;$id<=$#column_names;++$id) {
    print $column_names[$id],' ',$row->get_consolidator_result_by_id($id)->get_common,"\n";
  }
  print "\n";
}

AUTHOR

Michael Shipper

Source-Forge Project

As of version 0.001 the Project has been moved to Source-Forge.net

Data Range Compare https://sourceforge.net/projects/data-range-comp/

COPYRIGHT

Copyright 2011 Michael Shipper. All rights reserved.

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