lib/DBIx/Class/Storage/DBI/Replication.pm

   1 package DBIx::Class::Storage::DBI::Replication;
   2
   3 use strict;
   4 use warnings;
   5
   6 use DBIx::Class::Storage::DBI;
   7 use DBD::Multi;
   8 use base qw/Class::Accessor::Fast/;
   9
  10 __PACKAGE__->mk_accessors( qw/read_source write_source/ );
  11
  12 =head1 NAME
  13
  14 DBIx::Class::Storage::DBI::Replication - Replicated database support
  15
  16 =head1 SYNOPSIS
  17
  18   # change storage_type in your schema class
  19     $schema->storage_type( '::DBI::Replication' );
  20     $schema->connect_info( [
  21                      [ "dbi:mysql:database=test;hostname=master", "username", "password", { AutoCommit => 1 } ], # master
  22                      [ "dbi:mysql:database=test;hostname=slave1", "username", "password", { priority => 10 } ],  # slave1
  23                      [ "dbi:mysql:database=test;hostname=slave2", "username", "password", { priority => 10 } ],  # slave2
  24                      <...>
  25                     ] );
  26
  27 =head1 DESCRIPTION
  28
  29 This class implements replicated data store for DBI. Currently you can define one master and numerous slave database
  30 connections. All write-type queries (INSERT, UPDATE, DELETE and even LAST_INSERT_ID) are routed to master database,
  31 all read-type queries (SELECTs) go to the slave database.
  32
  33 For every slave database you can define a priority value, which controls data source usage pattern. It uses
  34 L<DBD::Multi>, so first the lower priority data sources used (if they have the same priority, the are used
  35 randomized), than if all low priority data sources fail, higher ones tried in order.
  36
  37 =cut
  38
  39 sub new {
  40     my $proto = shift;
  41     my $class = ref( $proto ) || $proto;
  42     my $self = {
  43         read_sources => [],
  44         read_iterator => 0,
  45     };
  46
  47     bless( $self, $class );
  48
  49     $self->write_source( DBIx::Class::Storage::DBI->new );
  50     $self->read_source( DBIx::Class::Storage::DBI->new );
  51
  52     return $self;
  53 }
  54
  55 sub all_sources {
  56     my $self = shift;
  57
  58     my @sources = ($self->{read_source}, $self->write_source);
  59
  60     return wantarray ? @sources : \@sources;
  61 }
  62
  63 sub connect_info {
  64     my( $self, $source_info ) = @_;
  65
  66     $self->write_source->connect_info( $source_info->[0] );
  67
  68     my @dsns = map { ($_->[3]->{priority} || 10) => $_ } @{$source_info}[1..@$source_info-1];
  69     $self->read_source->connect_info( [ 'dbi:Multi:', undef, undef, { dsns => \@dsns } ] );
  70 }
  71
  72 sub select {
  73     return shift->read_source()->select( @_ );
  74 }
  75 sub select_single {
  76     return shift->read_source()->select_single( @_ );
  77 }
  78 sub throw_exception {
  79     return shift->read_source()->throw_exception( @_ );
  80 }
  81 sub sql_maker {
  82     return shift->read_source()->sql_maker( @_ );
  83 }
  84 sub columns_info_for {
  85     return shift->read_source()->columns_info_for( @_ );
  86 }
  87 sub sqlt_type {
  88     return shift->read_source()->sqlt_type( @_ );
  89 }
  90 sub create_ddl_dir {
  91     return shift->read_source()->create_ddl_dir( @_ );
  92 }
  93 sub deployment_statements {
  94     return shift->read_source()->deployment_statements( @_ );
  95 }
  96 sub datetime_parser {
  97     return shift->read_source()->datetime_parser( @_ );
  98 }
  99 sub datetime_parser_type {
 100     return shift->read_source()->datetime_parser_type( @_ );
 101 }
 102 sub build_datetime_parser {
 103     return shift->read_source()->build_datetime_parser( @_ );
 104 }
 105
 106 sub limit_dialect {
 107     my $self = shift;
 108     $self->$_->limit_dialect( @_ ) for( $self->all_sources() );
 109 }
 110 sub quote_char {
 111     my $self = shift;
 112     $self->$_->quote_char( @_ ) for( $self->all_sources() );
 113 }
 114 sub name_sep {
 115     my $self = shift;
 116     $self->$_->quote_char( @_ ) for( $self->all_sources() );
 117 }
 118 sub disconnect {
 119     my $self = shift;
 120     $self->$_->disconnect( @_ ) for( $self->all_sources() );
 121 }
 122 sub DESTROY {
 123     my $self = shift;
 124
 125     $self->{write_source} = undef;
 126     $self->{read_sources} = undef;
 127 }
 128
 129 sub last_insert_id {
 130     return shift->write_source()->last_insert_id( @_ );
 131 }
 132 sub insert {
 133     return shift->write_source()->insert( @_ );
 134 }
 135 sub update {
 136     return shift->write_source()->update( @_ );
 137 }
 138 sub update_all {
 139     return shift->write_source()->update_all( @_ );
 140 }
 141 sub delete {
 142     return shift->write_source()->delete( @_ );
 143 }
 144 sub delete_all {
 145     return shift->write_source()->delete_all( @_ );
 146 }
 147 sub create {
 148     return shift->write_source()->create( @_ );
 149 }
 150 sub find_or_create {
 151     return shift->write_source()->find_or_create( @_ );
 152 }
 153 sub update_or_create {
 154     return shift->write_source()->update_or_create( @_ );
 155 }
 156 sub connected {
 157     return shift->write_source()->connected( @_ );
 158 }
 159 sub ensure_connected {
 160     return shift->write_source()->ensure_connected( @_ );
 161 }
 162 sub dbh {
 163     return shift->write_source()->dbh( @_ );
 164 }
 165 sub txn_begin {
 166     return shift->write_source()->txn_begin( @_ );
 167 }
 168 sub txn_commit {
 169     return shift->write_source()->txn_commit( @_ );
 170 }
 171 sub txn_rollback {
 172     return shift->write_source()->txn_rollback( @_ );
 173 }
 174 sub sth {
 175     return shift->write_source()->sth( @_ );
 176 }
 177 sub deploy {
 178     return shift->write_source()->deploy( @_ );
 179 }
 180
 181
 182 sub debugfh { shift->_not_supported( 'debugfh' ) };
 183 sub debugcb { shift->_not_supported( 'debugcb' ) };
 184
 185 sub _not_supported {
 186     my( $self, $method ) = @_;
 187
 188     die "This Storage does not support $method method.";
 189 }
 190
 191 =head1 SEE ALSO
 192
 193 L<DBI::Class::Storage::DBI>, L<DBD::Multi>, L<DBI>
 194
 195 =head1 AUTHOR
 196
 197 Norbert Csongrádi <bert@cpan.org>
 198
 199 Peter Siklósi <einon@ahq.hu>
 200
 201 =head1 LICENSE
 202
 203 You may distribute this code under the same terms as Perl itself.
 204
 205 =cut
 206
 207 1;