[memcache] disable listing keys when using Sasl

To support SASL authentication we need to switch to the binary protocol.
However, `getAllKeys` is not support when in binary protocol mode

Author: JorgenEvens

cache.php

@@ -51,8 +51,11 @@ function __construct($search = null) { parent::__construct('user', $search); }
             $memcache = new \Memcached();
             $memcacheVersion = 'memcached';
             $memcache->addServer(MEMCACHE_HOST, MEMCACHE_PORT);
-            if (!empty(MEMCACHE_USER) && !empty(MEMCACHE_PASSWORD))
+            if (!empty(MEMCACHE_USER) && !empty(MEMCACHE_PASSWORD)) {
+                $memcacheVersion = 'memcached-bin';
+                $memcache->setOption(Memcached::OPT_BINARY_PROTOCOL, true);
                 $memcache->setSaslAuthData(MEMCACHE_USER, MEMCACHE_PASSWORD);
+            }
             $memcache_stats = $memcache->getStats();
         } else if (extension_loaded('memcache')) {
             // This extension does not support SASL authentication
@@ -203,10 +206,11 @@ function memcache_get_key($key, &$found = false) {
 
     function memcache_ref() {
         global $memcache;
+        global $memcacheVersion;
 
         // Listing keys is not supported using the legacy Memcache module
         // PHP 7 and newer do not support this extension anymore
-        if (!extension_loaded('memcached'))
+        if ($memcacheVersion != 'memcached')
             return array();
 
         $items = $memcache->getAllKeys();
@@ -659,6 +663,10 @@ function sort_list(&$list) {
                                 </table>
                             </div>
                         <?php endif; ?>
+                    <?php elseif($memcacheVersion == 'memcached-bin'): ?>
+                        <p style="text-align: center">
+                            When SASL authentication is enabled on the <a href="https://pecl.php.net/package/memcached">memcached extension</a> we can not support listing keys
+                        </p>
                     <?php else: ?>
                         <p style="text-align: center">
                             Legacy <a href="https://pecl.php.net/package/memcache">memcache extension</a> does not support listing keys

demo/index.php

@@ -37,8 +37,10 @@ class CacheDemoClass {
 
         $memcache = new \Memcached();
         $memcache->addServer($memcache_host, $memcache_port);
-        if (!empty($memcache_user) && !empty($memcache_password))
+        if (!empty($memcache_user) && !empty($memcache_password)) {
+            $memcache->setOption(Memcached::OPT_BINARY_PROTOCOL, true);
             $memcache->setSaslAuthData($memcache_user, $memcache_password);
+        }
 
         $memcache->add('type.array', ['abc', 'def']);
         $memcache->add('type.string', 'hello-world');