X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FReplicated%2FBalancer%2FRandom.pm;h=f06875e16150e36f50c7a4d9d7b78776c44d959f;hb=47e6d13a64b4fb3ab2c89670afe895c240814abf;hp=2b0aef9c2916b0b36f140aaf7ea50a172d673815;hpb=ee356d004e088518205ac720b37c31a64c9cd861;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Storage/DBI/Replicated/Balancer/Random.pm b/lib/DBIx/Class/Storage/DBI/Replicated/Balancer/Random.pm
index 2b0aef9..f06875e 100644
--- a/lib/DBIx/Class/Storage/DBI/Replicated/Balancer/Random.pm
+++ b/lib/DBIx/Class/Storage/DBI/Replicated/Balancer/Random.pm
@@ -13,27 +13,29 @@ DBIx::Class::Storage::DBI::Replicated::Balancer::Random - A 'random' Balancer
 
 This class is used internally by L<DBIx::Class::Storage::DBI::Replicated>.  You
 shouldn't need to create instances of this class.
-    
+
 =head1 DESCRIPTION
 
 Given a pool (L<DBIx::Class::Storage::DBI::Replicated::Pool>) of replicated
 database's (L<DBIx::Class::Storage::DBI::Replicated::Replicant>), defines a
 method by which query load can be spread out across each replicant in the pool.
 
-This Balancer uses L<List::Util> keyword 'shuffle' to randomly pick an active
-replicant from the associated pool.  This may or may not be random enough for
-you, patches welcome.
-
 =head1 ATTRIBUTES
 
 This class defines the following attributes.
 
 =head2 master_read_weight
 
-A number from 0 to 1 that specifies what weight to give the master when choosing
-which backend to execute a read query on. A value of 0, which is the default,
-does no reads from master, while a value of 1 gives it the same priority as any
-single replicant.
+A number greater than 0 that specifies what weight to give the master when
+choosing which backend to execute a read query on. A value of 0, which is the
+default, does no reads from master, while a value of 1 gives it the same
+priority as any single replicant.
+
+For example: if you have 2 replicants, and a L</master_read_weight> of C<0.5>,
+the chance of reading from master will be C<20%>.
+
+You can set it to a value higher than 1, making master have higher weight than
+any single replicant, if for example you have a very powerful master.
 
 =cut
 
@@ -55,31 +57,33 @@ sub next_storage {
   my $self = shift @_;
 
   my @replicants = $self->pool->active_replicants;
+
+  if (not @replicants) {
+    # will fall back to master anyway
+    return;
+  }
+
   my $master     = $self->master;
 
-  my $rnd = $self->random_number(@replicants + $self->master_read_weight);
+  my $rnd = $self->_random_number(@replicants + $self->master_read_weight);
 
   return $rnd >= @replicants ? $master : $replicants[int $rnd];
 }
 
-=head2 random_number
-
-Returns a random number from 0 to x, not including x. Uses perl's
-L<perlfunc/rand> by default.
-
-=cut
-
-sub random_number {
+sub _random_number {
   rand($_[1])
 }
 
-=head1 AUTHOR
+=head1 FURTHER QUESTIONS?
 
-John Napiorkowski <john.napiorkowski@takkle.com>
+Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>.
 
-=head1 LICENSE
+=head1 COPYRIGHT AND LICENSE
 
-You may distribute this code under the same terms as Perl itself.
+This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE>
+by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can
+redistribute it and/or modify it under the same terms as the
+L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>.
 
 =cut