File Coverage

blib/lib/Loop/Sustainable/Strategy/MySQL/BalancedReplication.pm

Criterion	Covered	Total	%
statement	18	41	43.9
branch	0	16	0.0
condition			n/a
subroutine	6	8	75.0
pod	2	2	100.0
total	26	67	38.8

package Loop::Sustainable::Strategy::MySQL::BalancedReplication;

use strict;
use warnings;
use parent qw(Loop::Sustainable::Strategy);

use Carp;
use Class::Accessor::Lite (
    new => 0,
    rw  => [qw/dbh capable_behind_seconds on_error_scale_factor on_error_croak/],
);
use List::Util qw(max);

our $VERSION = '0.01';

sub new {
    my $class = shift;
    my $self = $class->SUPER::new(@_);
    unless ( exists $self->{capable_behind_seconds} ) {
        $self->{capable_behind_seconds} = 5;
    }
    unless ( exists $self->{on_error_scale_factor} ) {
        $self->{on_error_scale_factor} = 5;
    }
    unless ( exists $self->{on_error_croak} ) {
        $self->{on_error_croak} = 0;
    }
    $self;
}

sub wait_correction {
    my ( $self, $i, $elapsed, $rv ) = @_;

    my $second_behind_master; ;

    eval {
        my $dbh = $self->{dbh};
        my $status = $dbh->selectrow_hashref('SHOW SLAVE STATUS') or croak($dbh->errstr);
        if ( defined $status->{Seconds_Behind_Master} ) {
            $second_behind_master = $status->{Seconds_Behind_Master};
        }
    };
    if (my $e = $@) {
        if ( $self->{on_error_croak} ) {
            croak $e;
        }
        else {
            carp $e;
        }
    };

    unless ( defined $second_behind_master ) {
        $second_behind_master = max($self->{capable_behind_seconds}, 5) * $self->{on_error_scale_factor};
    }

    return max( ( $second_behind_master - $self->{capable_behind_seconds} ) / $self->check_strategy_interval, 0 );
}

1;

__END__