Data::ObjectDriver is a simple and transparent data interface library with caching capabilities. It provides an object-oriented interface to database tables and supports features like master-slave replication, partitioning, and caching using Memcached. Classes define the schema and connection details. Methods provide CRUD functionality and relationships. Custom drivers can be created to support different database architectures or caching strategies.

1. Data::ObjectDriver
id:clouder
Yokohama.pm #5

2. About D::OD
• Author: Benjamin Trott
• Recently Version: 0.06
• Simple, transparent data interface, with
caching.
• Based on MT::ObjectDriver in MT.
Now MT included D::OD.

3. D::OD features
• Built-in supportRAM and Apache inPartitioning.
Support Memcached,
Caching and
caching.
• Have to support master-slaver_handle()/rw_handle().
Can change process for read/write using
structure in mind.
• Implementation is becauseso less model feature.
But implement by myself,
thin, east-to-use.
of
Has ‘has_a’ but not has ‘has_many’.

4. Class structures
• Driver definition about how to connection to
Class for
class
db and cache server, and partitioning rules.
• Object classwhat you call.
The model class
Class for definition about how to treat data on tables.

5. Class structures
• Other classes
- D::OD::ResultSet
In the middle of an implementation?
Do not use in MT.
- D::OD::Profiler
Simple profiler.
- D::OD::GearmanDBI
I do not know how to use;)

6. Simple usase
• Make object class for table
Make sub-class of D::OD::BaseObject,
and set table information using install_properties().
‘driver’ is D::OD::Driver::DBI.

7. Simple usage
package Artist;
use strict;
use base qw( Data::ObjectDriver::BaseObject );
__PACKAGE__->install_properties(
datasource => 'artist',
columns => [ qw( id name orig_name band_id ) ],
primary_key => 'id',
driver => Data::ObjectDriver::Driver::DBI->new( %DB_INFO ),
);
1;

8. CRUD and etc
• Create
my artist = Artist->new(
name => ' ',
fullname => ' II '
);
$artist->save;
# or
Artist->bulk_insert( [col1, col2], [ [d1, d2], [d1, d2] ]);

9. CRUD and etc
• Read
my $artist = Artist->lookup(1);
print $artist->name;
# or
$artist_iter = Artist->search( { name => ' ' } );
@artists = Artist->search( { name => ' ' );
# or
$artists_ref = Artist->lookup_multi( [ 1, 2, 3 ] );

10. CRUD and etc
• Update
$artist->name( ' ' );
$artist->save;

11. CRUD and etc
• Delete
$artist->remove;

12. CRUD and etc
• has_a()
__PACKAGE__->has_a( {
class => 'Band',
column => 'band_id',
cached => 1,
} );

13. CRUD and etc
• add_trigger() post_load pre_search pre_insert
pre_save post_save
post_insert pre_update post_update pre_remove
post_remove post_inflate
__PACKAGE__->add_trigger(
pre_insert => sub {
my ( $obj, $orig_obj ) = @_;
...
},
);

14. Caching
• Only change driver
If there is not cache,
connect to db using D::OD::Driver::DBI.

15. Caching
package Artist;
use strict;
use base qw( Data::ObjectDriver::BaseObject );
__PACKAGE__->install_properties(
...
driver => Data::ObjectDriver::Driver::Cache::Memcached->new(
cache => Cache::Memcached->new( servers => @servers ),
fallback => Data::ObjectDriver::Driver::DBI->new( %DB_INFO ),
),
...
);
1;

16. Master-Slave structure
• Only override r_handle().in read process,
r_handle() is method that execute
so this method is used to connect to slave database.

17. Master-Slave structure
• Object class
package Artist;
use strict;
use base qw( Data::ObjectDriver::BaseObject );
__PACKAGE__->install_properties(
...
driver => Data::ObjectDriver::Driver::Cache::Memcached->new(
cache => Cache::Memcached->new( servers => @servers ),
fallback => ReplDriver->new( %DB_INFO, slaves => [ slave01, ... ] ),
),
...
);

18. Master-Slave structure
• Driver class
package ReplDriver;
use strict;
use base qw( Data::ObjectDriver::Driver::DBI );
__PACKAGE__->mk_accessors( qw( slaves ) );
sub init {
my $driver = shift;
my %param = @_;
$driver->slaves( delete $param{ slaves } );
$driver->SUPER::init( %param );
return $driver;
}
# cont.

19. Master-Slave structure
• Driver class(cont.)
# cont.
sub r_handle {
my $driver = shift;
my $db = shift || 'main';
for my $slave ( shuffle @{ $driver->slaves } ) {
# connect to $slave
my $dbh = DBI->connect( $slave->{DB_INFO} );
$driver->dbd->init_dbh($dbh);
return $dbh;
}
$driver->rw_handle($db);
}
1;

20. Partitioning
package CD;
use strict;
use base qw( Data::ObjectDriver::BaseObject );
__PACKAGE__->install_properties(
datasource => 'cd',
columns => [ qw( artist_id id title ) ],
primary_key => [ qw( artist_id id ) ],
driver => PartitionDriver->driver,
);
1;

21. Partitioning
package PartitionDriver;
use strict;
sub driver {
my $fallback = Data::ObjectDriver::Driver::Partition->new(
get_driver => &find_partition,
);
Data::ObjectDriver::Driver::Cache::Memcached->new(
cache => Cache::Memcached->new( servers => @servers ),
fallback => $fallback,
),
}
# cont.

22. Partitioning
# cont.
sub find_partition {
my ( $terms, $args ) = @_;
my $artist = Artist->lookup( $terms->{ artist_id } );
return ReplDriver->new(
%{ $artist->partition_obj->master },
slaves => $artist->partition_obj->slaves,
pk_generator => &pk_generator,
);
}
sub pk_generator {
my $obj = shift;
$obj->id( generate_id() );
1;
},
1;

23. Partitioning
my $cd = CD->new(
artist_id => 1,
title => ' '
);
$cd->save;
lookup() is depends on PartitionDriver implementation in partitioning.

24. At the end, I wish...
• Built-in support pager using Data::Page.
• Wants count() and more useful methods.
• Hard to execute simple SQL.
(Just do using D::OD::SQL?)
• And hard to execute ‘JOIN’.

25. Fin.