querycounter role, test for that and a new schema hierarchy for additional Moose...

[dbsrgits/DBIx-Class-Historic.git] / lib / DBIx / Class / Storage / DBI / Replication.pm

diff --git a/lib/DBIx/Class/Storage/DBI/Replication.pm b/lib/DBIx/Class/Storage/DBI/Replication.pm
index 42c3170..6ec74e9 100644 (file)
--- a/lib/DBIx/Class/Storage/DBI/Replication.pm
+++ b/lib/DBIx/Class/Storage/DBI/Replication.pm
@@ -11,7 +11,7 @@ __PACKAGE__->mk_accessors( qw/read_source write_source/ );
 
 =head1 NAME
 
-DBIx::Class::Storage::DBI::Replication - Replicated database support
+DBIx::Class::Storage::DBI::Replication - EXPERIMENTAL Replicated database support
 
 =head1 SYNOPSIS
 
@@ -21,18 +21,36 @@ DBIx::Class::Storage::DBI::Replication - Replicated database support
                     [ "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
-                    <...>
+                    [ $dbh, '','', {priority=>10}], # add in a preexisting database handle
+                    [ sub {  DBI->connect }, '', '', {priority=>10}], # DBD::Multi will call this coderef for connects
+                    <...>,
+                    { limit_dialect => 'LimitXY' } # If needed, see below
                    ] );
 
 =head1 DESCRIPTION
 
-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.
+Warning: This class is marked EXPERIMENTAL. It works for the authors but does
+not currently have automated tests so your mileage may vary.
 
-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.
+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
 
@@ -60,10 +78,34 @@ sub all_sources {
 sub connect_info {
     my( $self, $source_info ) = @_;
 
-    $self->write_source->connect_info( $source_info->[0] );
+    my( $info, $global_options, $options, @dsns );
+
+    $info = [ @$source_info ];
 
-    my @dsns = map { ($_->[3]->{priority} || 10) => $_ } @{$source_info}[1..@$source_info-1];
-    $self->read_source->connect_info( [ 'dbi:Multi:', undef, undef, { dsns => \@dsns } ] );
+    $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 } );
+
+       ## allow either a DSN string or an already connect $dbh.  Just remember if
+       ## you use the $dbh option then DBD::Multi has no idea how to reconnect in
+       ## the event of a failure.
+       
+    @dsns = map {
+        ## if the first element in the arrayhash is a ref, make that the value
+        my $db = ref $_->[0] ? $_->[0] : $_;
+        ($_->[3]->{priority} || 10) => $db;
+    } @{$info->[0]}[1..@{$info->[0]}-1];
+    
+    $global_options->{dsns} = \@dsns;
+
+    $self->read_source->connect_info( [ 'dbi:Multi:', undef, undef, { %$global_options } ] );
 }
 
 sub select {
@@ -100,22 +142,12 @@ 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 limit_dialect { $_->limit_dialect( @_ ) for( shift->all_sources ) }
+sub quote_char { $_->quote_char( @_ ) for( shift->all_sources ) }
+sub name_sep { $_->quote_char( @_ ) for( shift->all_sources ) }
+sub disconnect { $_->disconnect( @_ ) for( shift->all_sources ) }
+sub set_schema { $_->set_schema( @_ ) for( shift->all_sources ) }
+
 sub DESTROY {
     my $self = shift;