Fixes a Magento Enterprise performance bug related to the enterprise_index_refresh cron and Enterprise PageCache.

Veep_Patches_Model_PageCache_Observer_Index.php

<?php

/**
 * This core over-ride is the result of a BUG in the Enterprise method of
 * clearing it's PageCache.  During the Mview reindexing process, a changelog
 * of IDs is determined.  This array contains entity IDs that have been updated
 * since the last reindex and contains many duplicates.  When passed to
 * the PageCache methods to clear the cache, this array of IDs is not de-duped
 * which can result in hundreds of thousands of needless queries when bulk
 * updates are made.
 *
 * This code simply removes duplicate entries from this process thus very much
 * decreasing pagecache clearing times (which, with bulk updates can take
 * upwards of an hour).  This drops that to something like 2 minutes, max when
 * dealing with large datasets.
 *
 * Class Veep_Patches_Model_PageCache_Observer_Index
 */
class Veep_Patches_Model_PageCache_Observer_Index
    extends Enterprise_PageCache_Model_Observer_Index
{
    /**
     * {@inheritdoc}
     *
     * Overridden to account for getCacheIdTags returning false.
     *
     * @param Mage_Core_Model_Abstract $entity
     * @param array $ids
     */
    protected function _cleanEntityCache(Mage_Core_Model_Abstract $entity, array $ids)
    {
        $cacheTags = array();
        foreach ($ids as $entityId) {
            $entity->setId($entityId);
            $cache_id_tags = $entity->getCacheIdTags();
            if (false === $cache_id_tags) {
                $cache_id_tags = [];
            }
            $cacheTags = array_unique(array_merge($cacheTags, $cache_id_tags));
        }
        if ( ! empty($cacheTags)) {
            Enterprise_PageCache_Model_Cache::getCacheInstance()->clean($cacheTags);
        }
    }

    /**
     * {@inheritdoc}
     *
     * Overridden to account for getCacheIdTagsWithCategories returning false.
     *
     * @param Mage_Core_Model_Abstract $entity
     * @param array $ids
     */
    protected function _cleanProductsCache(Mage_Core_Model_Abstract $entity, array $ids)
    {
        $cacheTags = array();
        foreach ($ids as $entityId) {
            $entity->setId($entityId);
            $cache_id_tags_with_categories = $entity->getCacheIdTagsWithCategories();
            if (false === $cache_id_tags_with_categories) {
                $cache_id_tags_with_categories = [];
            }
            $cacheTags = array_unique(array_merge($cacheTags, $cache_id_tags_with_categories));
        }
        if ( ! empty($cacheTags)) {
            Enterprise_PageCache_Model_Cache::getCacheInstance()->clean($cacheTags);
        }
    }
    
    /**
     * @param Varien_Event_Observer $observer
     */
    public function cleanProductsCacheAfterPartialReindex(Varien_Event_Observer $observer)
    {
        $entityIds = $observer->getEvent()->getData('product_ids');
        // Start fix
        $newProductIds = array_unique($entityIds);
        // End fix
        if (is_array($newProductIds) && ! empty($newProductIds)) {
            Mage::log(sprintf(
                '[ %s ] Found [ %u ] distinct Product IDs out of the original [ %u ]',
                date('h:i:s', time()),
                count($newProductIds),
                count($entityIds)
            ), null, 'veep_fixes.log');
            $this->_cleanProductsCache(Mage::getModel('catalog/product'), $newProductIds);
        }
    }

    /**
     * @param Varien_Event_Observer $observer
     */
    public function cleanCategoriesCacheAfterPartialReindex(Varien_Event_Observer $observer)
    {
        $entityIds = $observer->getEvent()->getData('category_ids');
        // Start fix
        $newEntityIds = array_unique($entityIds);
        // End fix
        if (is_array($entityIds) && ! empty($entityIds)) {
            Mage::log(sprintf(
                '[ %s ] Found [ %u ] distinct Category IDs out of the original [ %u ]',
                date('h:i:s', time()),
                count($newEntityIds),
                count($entityIds)
            ), null, 'veep_fixes.log');
            $this->_cleanEntityCache(Mage::getModel('catalog/category'), $entityIds);
            Enterprise_PageCache_Model_Cache::getCacheInstance()->clean(Mage_Catalog_Model_Category::CACHE_TAG);
        }
    }
}