[V5˖] Fetching all keys

As of 9.2 (January 2024):

As of the v9.2 there's a limited support to retrieve all keys natively with an optional $pattern parameter which is limited to some drivers.

The method ExtendedCacheItemInterface::getAllItems(string $pattern = '') allows you to retrieve all the cache items from the backend with an internal hard-limitation of 9999 elements.

The following table will let you see the support of this feature as of v9.2:

Driver name	getAllItems() Support	$pattern parameter support	Information
Apcu	🔴	🔴
Arangodb	🔴	🔴
Cassandra	🔴	🔴
Couchbasev3	🔴	🔴
Couchdb	✅	🔴	No native pattern support.
Devnull	🔴	🔴
Devrandom	🔴	🔴
Dynamodb	🔴	🔴
Files	🔴	🔴
Firestore	✅	🔴	No native pattern support.
Leveldb	🔴	🔴
Memcache	🔴	🔴
Memcached	🟧	🔴	No native pattern support. The internal getAllKeys() method of Memcached is broken on some versions.
Memstatic	✅	✅	Pattern support in development.
Mongodb	✅	✅
Predis	✅	✅	Planned
Redis	✅	✅	Pattern documentation
Solr	✅	✅	Pattern documentation
Sqlite	🔴	🔴
Ssdb	🔴	🔴
Wincache	🔴	🔴
Zenddisk	🔴	🔴
Zendshm	🔴	🔴

Legend: ✅ Full support, 🟧 Partial support, 🔴 No support, 🚧 Planned/In development

Prior 9.2:

Before the v9.2 was released, there's a tweak to allow you to "fetch all keys" from the cache: You can achieve this using tags for a reasonable amount of cache items (less than 10k, except if you have a consequent server memory setting up).

<?php
/**
 *
 * This file is part of phpFastCache.
 *
 * @license MIT License (MIT)
 *
 * For full copyright and license information, please see the docs/CREDITS.txt file.
 *
 * @author Khoa Bui (khoaofgod)  <khoaofgod@gmail.com> http://www.phpfastcache.com
 * @author Georges.L (Geolim4)  <contact@geolim4.com>
 *
 */
use phpFastCache\CacheManager;

// Include composer autoloader
require __DIR__ . '/../../vendor/autoload.php';

$InstanceCache = CacheManager::getInstance('files');
$InstanceCache->clear();

/**
 * @var $keys \phpFastCache\Core\Item\ExtendedCacheItemInterface[]
 */
$keyPrefix = "product_page_";
$keys = [];

for ($i=1;$i<=10;$i++)
{
    $keys[$keyPrefix . $i] = $InstanceCache->getItem($keyPrefix . $i);
    if(!$keys[$keyPrefix . $i]->isHit()){
        $keys[$keyPrefix . $i]
          ->set(uniqid('pfc', true))
          ->addTag('pfc');
    }
}

$InstanceCache->saveMultiple($keys);

/**
 * Remove items references from memory
 */
unset($keys);
$InstanceCache->detachAllItems();
gc_collect_cycles();


/**
 * Now get the items by a specific tag
 */
$keys = $InstanceCache->getItemsByTag('pfc');
foreach ($keys as $key) {
    echo "Key: {$key->getKey()} =&gt; {$key->get()}<br />";
}

By this way you can retrieve every keys in cache tagged "pfc".