--- /dev/null
+package DBIx::Class::Storage::DBI::Replication;
+
+use strict;
+use warnings;
+
+use DBIx::Class::Storage::DBI;
+use DBD::Multi;
+use base qw/Class::Accessor::Fast/;
+
+__PACKAGE__->mk_accessors( qw/read_source write_source/ );
+
+=head1 NAME
+
+DBIx::Class::Storage::DBI::Replication - EXPERIMENTAL Replicated database support
+
+=head1 SYNOPSIS
+
+ # change storage_type in your schema class
+ $schema->storage_type( '::DBI::Replication' );
+ $schema->connect_info( [
+ [ "dbi:mysql:database=test;hostname=master", "username", "password", { AutoCommit => 1 } ], # master
+ [ "dbi:mysql:database=test;hostname=slave1", "username", "password", { priority => 10 } ], # slave1
+ [ "dbi:mysql:database=test;hostname=slave2", "username", "password", { priority => 10 } ], # slave2
+ <...>,
+ { limit_dialect => 'LimitXY' } # If needed, see below
+ ] );
+
+=head1 DESCRIPTION
+
+Warning: This class is marked EXPERIMENTAL. It works for the authors but does
+not currently have automated tests so your mileage may vary.
+
+This class implements replicated data store for DBI. Currently you can define one master and numerous slave database
+connections. All write-type queries (INSERT, UPDATE, DELETE and even LAST_INSERT_ID) are routed to master database,
+all read-type queries (SELECTs) go to the slave database.
+
+For every slave database you can define a priority value, which controls data source usage pattern. It uses
+L<DBD::Multi>, so first the lower priority data sources used (if they have the same priority, the are used
+randomized), than if all low priority data sources fail, higher ones tried in order.
+
+=head1 CONFIGURATION
+
+=head2 Limit dialect
+
+If you use LIMIT in your queries (effectively, if you use SQL::Abstract::Limit), do not forget to set up limit_dialect (perldoc SQL::Abstract::Limit) by passing it as an option in the (optional) hash reference to connect_info.
+DBIC can not set it up automatically, since it can not guess DBD::Multi connection types.
+
+=cut
+
+sub new {
+ my $proto = shift;
+ my $class = ref( $proto ) || $proto;
+ my $self = {};
+
+ bless( $self, $class );
+
+ $self->write_source( DBIx::Class::Storage::DBI->new );
+ $self->read_source( DBIx::Class::Storage::DBI->new );
+
+ return $self;
+}
+
+sub all_sources {
+ my $self = shift;
+
+ my @sources = ($self->read_source, $self->write_source);
+
+ return wantarray ? @sources : \@sources;
+}
+
+sub connect_info {
+ my( $self, $source_info ) = @_;
+
+ my( $info, $global_options, $options, @dsns );
+
+ $info = [ @$source_info ];
+
+ $global_options = ref $info->[-1] eq 'HASH' ? pop( @$info ) : {};
+ if( ref( $options = $info->[0]->[-1] ) eq 'HASH' ) {
+ # Local options present in dsn, merge them with global options
+ map { $global_options->{$_} = $options->{$_} } keys %$options;
+ pop @{$info->[0]};
+ }
+
+ # We need to copy-pass $global_options, since connect_info clears it while processing options
+ $self->write_source->connect_info( [ @{$info->[0]}, { %$global_options } ] );
+
+ @dsns = map { ($_->[3]->{priority} || 10) => $_ } @{$info}[1..@$info-1];
+ $global_options->{dsns} = \@dsns;
+
+ $self->read_source->connect_info( [ 'dbi:Multi:', undef, undef, { %$global_options } ] );
+}
+
+sub select {
+ shift->read_source->select( @_ );
+}
+sub select_single {
+ shift->read_source->select_single( @_ );
+}
+sub throw_exception {
+ shift->read_source->throw_exception( @_ );
+}
+sub sql_maker {
+ shift->read_source->sql_maker( @_ );
+}
+sub columns_info_for {
+ shift->read_source->columns_info_for( @_ );
+}
+sub sqlt_type {
+ shift->read_source->sqlt_type( @_ );
+}
+sub create_ddl_dir {
+ shift->read_source->create_ddl_dir( @_ );
+}
+sub deployment_statements {
+ shift->read_source->deployment_statements( @_ );
+}
+sub datetime_parser {
+ shift->read_source->datetime_parser( @_ );
+}
+sub datetime_parser_type {
+ shift->read_source->datetime_parser_type( @_ );
+}
+sub build_datetime_parser {
+ shift->read_source->build_datetime_parser( @_ );
+}
+
+sub limit_dialect {
+ my $self = shift;
+ $self->$_->limit_dialect( @_ ) for( $self->all_sources );
+}
+sub quote_char {
+ my $self = shift;
+ $self->$_->quote_char( @_ ) for( $self->all_sources );
+}
+sub name_sep {
+ my $self = shift;
+ $self->$_->quote_char( @_ ) for( $self->all_sources );
+}
+sub disconnect {
+ my $self = shift;
+ $self->$_->disconnect( @_ ) for( $self->all_sources );
+}
+sub DESTROY {
+ my $self = shift;
+
+ undef $self->{write_source};
+ undef $self->{read_sources};
+}
+
+sub last_insert_id {
+ shift->write_source->last_insert_id( @_ );
+}
+sub insert {
+ shift->write_source->insert( @_ );
+}
+sub update {
+ shift->write_source->update( @_ );
+}
+sub update_all {
+ shift->write_source->update_all( @_ );
+}
+sub delete {
+ shift->write_source->delete( @_ );
+}
+sub delete_all {
+ shift->write_source->delete_all( @_ );
+}
+sub create {
+ shift->write_source->create( @_ );
+}
+sub find_or_create {
+ shift->write_source->find_or_create( @_ );
+}
+sub update_or_create {
+ shift->write_source->update_or_create( @_ );
+}
+sub connected {
+ shift->write_source->connected( @_ );
+}
+sub ensure_connected {
+ shift->write_source->ensure_connected( @_ );
+}
+sub dbh {
+ shift->write_source->dbh( @_ );
+}
+sub txn_begin {
+ shift->write_source->txn_begin( @_ );
+}
+sub txn_commit {
+ shift->write_source->txn_commit( @_ );
+}
+sub txn_rollback {
+ shift->write_source->txn_rollback( @_ );
+}
+sub sth {
+ shift->write_source->sth( @_ );
+}
+sub deploy {
+ shift->write_source->deploy( @_ );
+}
+
+
+sub debugfh { shift->_not_supported( 'debugfh' ) };
+sub debugcb { shift->_not_supported( 'debugcb' ) };
+
+sub _not_supported {
+ my( $self, $method ) = @_;
+
+ die "This Storage does not support $method method.";
+}
+
+=head1 SEE ALSO
+
+L<DBI::Class::Storage::DBI>, L<DBD::Multi>, L<DBI>
+
+=head1 AUTHOR
+
+Norbert Csongrádi <bert@cpan.org>
+
+Peter Siklósi <einon@einon.hu>
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+
+=cut
+
+1;
projects / dbsrgits/DBIx-Class.git / commitdiff