[blog] Le cache des blocks sur Magento (http://jacques.sh/le-cache-des-blocks-sur-magento.html)

example_01.php

<?php

namespace Jbh;

class Counter
{
    use \Jbh\Db;
    
    protected $_cache = [];
    
    protected $_cacheKey = 'jbh_counter_sql_result';
    
    public function getCountLessThan($id)
    {
        $sql = "SELECT COUNT(`id`) AS n FROM `table` WHERE `id` < %d;";
        $key = sprintf($this->_cacheKey, $id);
        if (!isset($this->_cache[$key])) {
            $this->_cache[$key] = $this->query(sprintf($sql, $id))->fetchOne('n');
        }
        return $this->_cache[$key];
    }
}

$counter = new \Jbh\Counter;
echo $counter->getCountLessThan(3), ",";
echo $counter->getCountLessThan(10);

// Affiche : 2,2

example_02.php

<?php

$counter = new \Jbh\Counter;

echo $counter->getCountLessThan(3), ",";
echo $counter->getCountLessThan(10);

// Affiche : 2,9

example_03.txt

Cache A:
    key         => cache_a
    tags        => foo, bar, baz
    lifetime    => false
    
Cache B:
    key         => cache_b
    tags        => foo, bar
    lifetime    => 10
    
Cache C:
    key         => cache_c
    tags        => baz, qux
    lifetime    => 62400

example_04.php

<?php

$tags = ['foo'];
Mage::app()->cleanCache($tags);

example_05.php

<?php

$tags = ['baz', 'qux'];
Mage::app()
    ->getCache()
    ->getFrontend()
    ->clean(Zend_Cache::CLEANING_MODE_MATCHING_TAG, $tags);

// Constantes à utiliser pour nettoyer le cache de manière conditionnelle :
// Zend_Cache::CLEANING_MODE_ALL                = 'all';
// Zend_Cache::CLEANING_MODE_OLD                = 'old';
// Zend_Cache::CLEANING_MODE_MATCHING_TAG       = 'matchingTag';
// Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG   = 'notMatchingTag';
// Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG   = 'matchingAnyTag';     <=== Par défaut sur Magento

example_06.php

<?php

$block->getCacheKey();
$block->getCacheLifetime();
$block->getCacheTags();

example_07.php

<?php

abstract class Mage_Core_Block_Abstract extends Varien_Object
{

    /* ... */

    public function getCacheKey()
    {
        if ($this->hasData('cache_key')) {
            return $this->getData('cache_key');
        }
        /**
         * don't prevent recalculation by saving generated cache key
         * because of ability to render single block instance with different data
         */
        $key = $this->getCacheKeyInfo();
        //ksort($key);  // ignore order
        $key = array_values($key);  // ignore array keys
        $key = implode('|', $key);
        $key = sha1($key);
        return $key;
    }

    /* ... */

}

example_08.php

<?php

abstract class Mage_Core_Block_Abstract extends Varien_Object
{

    /* ... */

    public function getCacheKeyInfo()
    {
        return array(
            $this->getNameInLayout()
        );
    }

    /* ... */

}

example_09.php

<?php

public function getCacheKeyInfo()
{
    // Utilisation d'index pour pouvoir faire un array_merge au besoin ;)
    // Par exemple si ce tableau est en partie dans un Helper pour faciliter les développement ?

    return array(
        'name_in_layout'    => $this->getNameInLayout(),
        'store'             => Mage::app()->getStore()->getId(),
        'design_package'    => Mage::getDesign()->getPackageName(),
        'design_theme'      => Mage::getDesign()->getTheme('template'),
//        'object_id'         => $this->getObjectId()
    );
}

example_10.php

<?php

abstract class Mage_Core_Block_Abstract extends Varien_Object
{

    /* ... */

    public function getCacheTags()
    {
        if (!$this->hasData('cache_tags')) {
            $tags = array();
        } else {
            $tags = $this->getData('cache_tags');
        }
        $tags[] = self::CACHE_GROUP;
        return $tags;
    }

    /* ... */

}

example_11.php

<?php

class Jbh_Demo_Model_Foo extends Mage_Core_Model_Abstract
{
    const CACHE_TAG = 'FOO';

    public function getCacheTags()
    {
        $tags = parent::getCacheTags();
        array_push(
            $tags,
            Jbh_Demo_Model_Foo::CACHE_TAG,
            Jbh_Demo_Model_Foo::CACHE_TAG . '_' . $this->getObjectId()
        );

        return $tags;
    }

}

example_12.php

<?php

public function getCacheLifetime()
{
    return 36000; // 10h
}

example_13.php

<?php

public function saveCache($data, $id, $tags=array(), $lifeTime=false)
{
    $this->_cache->save($data, $id, $tags, $lifeTime);
    Mage::log($tags, null, 'tags.log', true);
    return $this;
}

example_14.php

<?php

public function cleanCache($tags=array())
{
    $this->_cache->clean($tags);
    Mage::log($tags, null, 'tags.log', true);
    Mage::dispatchEvent('application_clean_cache', array('tags' => $tags));
    return $this;
}