Posts Tagged ‘Rdo’

7. Dezember 2015

by

In: horde

Kommentare deaktiviert für Horde_Rdo Many to Many relations and Horde DB Migrator

Many to Many relations btween to object types or table rows are usually saved to a database using a third table.

For example, if every server can have multiple services and each service can run on multiple computers, we need a third table to store the relations:

server table:
server_id | server_name
        1 | hoellenhund.internal.company.com
        2 | forellenfisch.internal.company.com
service table:
service_id | service_name
         1 | tomcat
         2 | dovecot
relation table:
service_id | server_id
         1 | 1
         2 | 2
         2 | 1

Horde’s ORM Layer Horde_Rdo supports creating, checking and changing such relations but it’s not very prominently documented.

Let’s look at an example.

First, we need to create the database schema. Note that the relations table has no autoincrement key, only the two columns used for lookup


/usr/share/php5/PEAR/www/horde/hvview/migration # cat 1_hvview_base_tables.php
/**
* Create Hvview base tables.
*
* Copyright 2015-2015 B1 Systems GmbH (http://www.b1-systems.de/)
*
* See the enclosed file COPYING for license information (GPL). If you
* did not receive this file, see http://www.horde.org/licenses/gpl.
*
* @author Ralf Lang
* @package Hvview
*/
class HvviewBaseTables extends Horde_Db_Migration_Base
{
/**
* Upgrade
*/
public function up()
{

$t = $this->createTable('hvview_technical_landscapes', array('autoincrementKey' => 'landscape_id'));
$t->column('landscape_name', 'string', array('limit' => 255, 'null' => false));
$t->column('period_id', 'integer', array('limit' => 11, 'null' => false));
$t->end();

$t = $this->createTable('hvview_resource_pools', array('autoincrementKey' => 'resource_pool_id'));
$t->column('pool_name', 'string', array('limit' => 255, 'null' => false));
$t->column('landscape_id', 'integer', array('limit' => 11, 'null' => false));
$t->column('period_id', 'integer', array('limit' => 11, 'null' => false));
$t->end();

$t = $this->createTable('hvview_hardware_pools', array('autoincrementKey' => 'hardware_pool_id'));
$t->column('pool_name', 'string', array('limit' => 255, 'null' => false));
$t->column('landscape_id', 'integer', array('limit' => 11, 'null' => false)); /* possibly redundant, but may speed up things */
$t->column('period_id', 'integer', array('limit' => 11, 'null' => false));
$t->end();

/*Relations table*/
$t = $this->createTable('hvview_rp_hwps', array('autoincrementKey' => false));
$t->column('resource_pool_id', 'integer', array('limit' => 11, 'null' => false));
$t->column('hardware_pool_id', 'integer', array('limit' => 11, 'null' => false));
$t->end();

$t = $this->createTable('hvview_periods', array('autoincrementKey' => 'period_id'));
$t->column('period_ts', 'integer', array('limit' => 11, 'null' => false));
$t->end();

/* We collapse hypervisor and blade server objects into one for now - let`s see if this scales well */
$t = $this->createTable('hvview_servers', array('autoincrementKey' => 'server_id'));
$t->column('period_id', 'integer', array('limit' => 11, 'null' => false));
$t->column('hardware_pool_id', 'integer', array('limit' => 11, 'null' => false));
$t->column('hostname', 'string', array('limit' => 100, 'null' => false));
$t->column('state', 'string', array('limit' => 20, 'null' => true));
$t->column('os_release', 'string', array('limit' => 20, 'null' => true));
$t->column('comment', 'string', array('limit' => 255, 'null' => true));
$t->column('hv_free_vcpu', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_free_memory', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_free_disk', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_total_vcpu', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_total_memory', 'integer', array('limit' => 11, 'null' => true));
$t->column('hv_excluded', 'integer', array('limit' => 1, 'null' => true));
$t->column('hv_vm_count', 'integer', array('limit' => 3, 'null' => true));
$t->end();

// Indices not before we have an idea which of them we need most
// $this->addIndex('hvview_items', array('item_owner'));

}

/**
* Downgrade
*/
public function down()
{
$this->dropTable('hvview_technical_landscapes');
$this->dropTable('hvview_resource_pools');
$this->dropTable('hvview_hardware_pools');
$this->dropTable('hvview_periods');
$this->dropTable('hvview_servers');
$this->dropTable('hvview_rp_hwps');
}
}

The relations are defined in a Horde_Rdo_Mapper class which also knows how to spawn objects from the rows.

The Objects

/usr/share/php5/PEAR/www/horde/hvview/lib/Entity # cat ResourcePool.php 

The Mappers:

/usr/share/php5/PEAR/www/horde/hvview/lib/Entity # cat ResourcePoolMapper.php 
 array('type' => Horde_Rdo::MANY_TO_MANY,
                          'through' => 'hvview_rp_hwps',
                          'mapper' => 'Hvview_Entity_HardwarePoolMapper')
    
            );

}

/usr/share/php5/PEAR/www/horde/hvview/lib/Entity # cat HardwarePoolMapper.php 
 array('type' => Horde_Rdo::MANY_TO_MANY,
                          'through' => 'hvview_rp_hwps',
                          'mapper' => 'Hvview_Entity_ResourcePoolMapper')
    
            );

}

The relation is defined in both direction and only loaded on-demand ("lazy") as opposed to upfront when the item is created from the database rows.
Now let's fetch two items and link them:

You can do this through the mapper or through one of the two partners

Adding a relation to an object using the object

// $rm is a ResourcePoolMapper instance
// $hm is a HardwarePoolMapper instance
$rp = $rm->findOne(); // In reality, you would not pick a random item but add some criteria
$hwp = $hm->findOne();
$rp->addRelation('hwps', $hwp);

Adding a relation to an object using the mapper

// $rm is a ResourcePoolMapper instance
// $hm is a HardwarePoolMapper instance
$rp = $rm->findOne(); // In reality, you would not pick a random item but add some criteria
$hwp = $hm->findOne();
$rm->addRelation('hwps', $rp, $hwp);

10. Mai 2012

by

In: Allgemein, horde, OpenSUSE, Tech

4 comments

Dear folks, I am very pleased to announce:
The Sesha Inventory application is ready for Horde 5 and it is in good shape. Sesha is a simple inventory keeping application which originally developed by Bo Daley and Andrew Coleman on Horde 3. The product was never officially released but it went into production at several sites. Sesha release cycle can now start together with the Horde 5 Alpha release cycle.

Sesha inventory can be configured to hold any number of stock categories with any number and type of attributes.
Like the original version, Sesha for Horde 5 can provide its stock categories as ticket queues for the horde ticketing application whups.
There are a lot of plans and ideas for upcoming versions but for this time the focus was on finishing a releasable product.There are no surprises for existing users of Horde 3 based sesha. Most work happened invisibly under the hood:

  • The Horde_Template library was exchanged by new Horde_View code
  • A migration script for database was added
  • Users can keep their original Horde 3 Sesha tables and data.
  • The sql backend driver was completely reworked into a driver based on the Horde_Rdo ORM library The new Driver Api provides enhanced search capabilities but the current frontend doesn’t make use of it. I do not plan to add any features to the classic view but start working on an Ajax view once the Horde 5 Redesign is completed. This may ship with Sesha 1.1 later on.
  • Object oriented code has replaced complicated hashes in many places

The Horde Rdo library is the new work horse inside Sesha. Rdo means Rampage Data Objects and is a lightweight ORM layer by Horde founder Chuck Hagenbuch. It maps database tables to PHP Objects. This is similar to the ActiveRecord pattern. Each database row can be turned into one Rdo item. For Sesha and another – non-public – software project, some enhancements went into the Rdo library for Horde 5:

  • Rdo now provides a caching factory or root object which speeds up creation of mapper objects
  • Methods for add, removing or checking many-to-many relations have been added
  • A number of edge case bugs have been fixed

I think the Horde 5 release cycle will start with alpha1 releases sometime in May. I know we’re a little late but it’s worth the wait.
That said, I welcome any early testing or updates of the language files. Provided everything works as expected, Sesha will be shipped with Horde 5 for OpenSUSE 12.2