lib/Catalyst/Model/DBIC/Schema/Trait/Replicated.pm

   1 package Catalyst::Model::DBIC::Schema::Trait::Replicated;
   2
   3 use Moose::Role;
   4 use Moose::Autobox;
   5 use Carp::Clan '^Catalyst::Model::DBIC::Schema';
   6
   7 use Catalyst::Model::DBIC::Schema::Types 'ConnectInfos';
   8
   9 use namespace::clean -except => 'meta';
  10
  11 =head1 NAME
  12
  13 Catalyst::Model::DBIC::Schema::Trait::Replicated - Replicated storage support for
  14 L<Catalyst::Model::DBIC::Schema>
  15
  16 =head1 SYNOPSiS
  17
  18     __PACKAGE__->config({
  19         traits => ['Replicated']
  20         connect_info =>
  21             ['dbi:mysql:master', 'user', 'pass'],
  22         replicants => [
  23             ['dbi:mysql:slave1', 'user', 'pass'],
  24             ['dbi:mysql:slave2', 'user', 'pass'],
  25             ['dbi:mysql:slave3', 'user', 'pass'],
  26         ],
  27         balancer_args => {
  28           master_read_weight => 0.3
  29         }
  30     });
  31
  32 =head1 DESCRIPTION
  33
  34 Sets your storage_type to L<DBIx::Class::Storage::DBI::Replicated> and connects
  35 replicants provided in config. See that module for supported resultset
  36 attributes.
  37
  38 The default L<DBIx::Class::Storage::DBI::Replicated/balancer_type> is
  39 C<::Random>.
  40
  41 Sets the
  42 L<DBIx::Class::Storage::DBI::Replicated::Balancer::Random/master_read_weight> to
  43 C<1> by default, meaning that you have the same chance of reading from master as
  44 you do from replicants. Set to C<0> to turn off reads from master.
  45
  46 =head1 CONFIG PARAMETERS
  47
  48 =head2 replicants
  49
  50 Array of connect_info settings for every replicant.
  51
  52 =cut
  53
  54 has replicants => (
  55     is => 'ro', isa => ConnectInfos, coerce => 1, required => 1
  56 );
  57
  58 after setup => sub {
  59     my $self = shift;
  60
  61 # check storage_type compatibility (if configured)
  62     if (my $storage_type = $self->storage_type) {
  63         my $class = $storage_type =~ /^::/ ?
  64             "DBIx::Class::Storage$storage_type"
  65             : $storage_type;
  66
  67         croak "This storage_type cannot be used with replication"
  68             unless $class->isa('DBIx::Class::Storage::DBI::Replicated');
  69     } else {
  70         $self->storage_type('::DBI::Replicated');
  71     }
  72
  73     $self->connect_info->{balancer_type} ||= '::Random'
  74         unless $self->connect_info->{balancer_type};
  75
  76     unless ($self->connect_info->{balancer_args} &&
  77             exists $self->connect_info->{balancer_args}{master_read_weight}) {
  78         $self->connect_info->{balancer_args}{master_read_weight} = 1;
  79     }
  80 };
  81
  82 my $build = sub {
  83     my $self = shift;
  84
  85     $self->storage->connect_replicants(map [ $_ ], $self->replicants->flatten);
  86 };
  87 after BUILD => $build;
  88 sub BUILD { goto $build }
  89
  90 =head1 SEE ALSO
  91
  92 L<Catalyst::Model::DBIC::Schema>, L<DBIx::Class>,
  93 L<DBIx::Class::Storage::DBI::Replicated>,
  94 L<Cache::FastMmap>, L<DBIx::Class::Cursor::Cached>
  95
  96 =head1 AUTHOR
  97
  98 Rafael Kitover, C<rkitover at cpan.org>
  99
 100 =head1 COPYRIGHT
 101
 102 This program is free software, you can redistribute it and/or modify it
 103 under the same terms as Perl itself.
 104
 105 =cut
 106
 107 1;