MDL-57572 cache: Adds igbinary serializer to Redis cache store

cache/stores/redis/addinstanceform.php

@@ -48,5 +48,11 @@ class cachestore_redis_addinstance_form extends cachestore_addinstance_form {
         $form->setType('prefix', PARAM_TEXT); // We set to text but we have a rule to limit to alphanumext.
         $form->addHelpButton('prefix', 'prefix', 'cachestore_redis');
         $form->addRule('prefix', get_string('prefixinvalid', 'cachestore_redis'), 'regex', '#^[a-zA-Z0-9\-_]+$#');
+
+        $serializeroptions = cachestore_redis::config_get_serializer_options();
+        $form->addElement('select', 'serializer', get_string('useserializer', 'cachestore_redis'), $serializeroptions);
+        $form->addHelpButton('serializer', 'useserializer', 'cachestore_redis');
+        $form->setDefault('serializer', Redis::SERIALIZER_PHP);
+        $form->setType('serializer', PARAM_INT);
     }
 }

cache/stores/redis/lang/en/cachestore_redis.php

@@ -30,7 +30,15 @@ $string['prefix_help'] = 'This prefix is used for all key names on the Redis ser
 * If you only have one Moodle instance using this server, you can leave this value default.
 * Due to key length restrictions, a maximum of 5 characters is permitted.';
 $string['prefixinvalid'] = 'Invalid prefix. You can only use a-z A-Z 0-9-_.';
+$string['serializer_igbinary'] = 'The igbinary serializer.';
+$string['serializer_php'] = 'The default PHP serializer.';
+$string['server'] = 'Server';
+$string['server_help'] = 'This sets the hostname or IP address of the Redis server to use.';
 $string['test_server'] = 'Test server';
 $string['test_server_desc'] = 'Redis server to use for testing.';
-$string['server'] = 'Server';
-$string['server_help'] = 'This sets the hostname or IP address of the Redis server to use.';
+$string['test_serializer'] = 'Serializer';
+$string['test_serializer_desc'] = 'Serializer to use for testing.';
+$string['useserializer'] = 'Use serializer';
+$string['useserializer_help'] = 'Specifies the serializer to use for serializing.
+The valid serializers are Redis::SERIALIZER_PHP or Redis::SERIALIZER_IGBINARY.
+The latter is supported only when phpredis is configured with --enable-redis-igbinary option and the igbinary extension is loaded.';

cache/stores/redis/lib.php

@@ -73,6 +73,13 @@ class cachestore_redis extends cache_store implements cache_is_key_aware, cache_
      */
     protected $redis;
 
+    /**
+     * Serializer for this store.
+     *
+     * @var int
+     */
+    protected $serializer = Redis::SERIALIZER_PHP;
+
     /**
      * Determines if the requirements for this type of store are met.
      *
@@ -124,6 +131,9 @@ class cachestore_redis extends cache_store implements cache_is_key_aware, cache_
         if (!array_key_exists('server', $configuration) || empty($configuration['server'])) {
             return;
         }
+        if (array_key_exists('serializer', $configuration)) {
+            $this->serializer = (int)$configuration['serializer'];
+        }
         $prefix = !empty($configuration['prefix']) ? $configuration['prefix'] : '';
         $this->redis = $this->new_redis($configuration['server'], $prefix);
     }
@@ -145,7 +155,7 @@ class cachestore_redis extends cache_store implements cache_is_key_aware, cache_
             $port = $serverconf[1];
         }
         if ($redis->connect($server, $port)) {
-            $redis->setOption(Redis::OPT_SERIALIZER, Redis::SERIALIZER_PHP);
+            $redis->setOption(Redis::OPT_SERIALIZER, $this->serializer);
             if (!empty($prefix)) {
                 $redis->setOption(Redis::OPT_PREFIX, $prefix);
             }
@@ -426,7 +436,11 @@ class cachestore_redis extends cache_store implements cache_is_key_aware, cache_
      * @return array
      */
     public static function config_get_configuration_array($data) {
-        return array('server' => $data->server, 'prefix' => $data->prefix);
+        return array(
+            'server' => $data->server,
+            'prefix' => $data->prefix,
+            'serializer' => $data->serializer
+        );
     }
 
     /**
@@ -440,6 +454,9 @@ class cachestore_redis extends cache_store implements cache_is_key_aware, cache_
         $data = array();
         $data['server'] = $config['server'];
         $data['prefix'] = !empty($config['prefix']) ? $config['prefix'] : '';
+        if (!empty($config['serializer'])) {
+            $data['serializer'] = $config['serializer'];
+        }
         $editform->set_data($data);
     }
 
@@ -458,7 +475,11 @@ class cachestore_redis extends cache_store implements cache_is_key_aware, cache_
         if (empty($config->test_server)) {
             return false;
         }
-        $cache = new cachestore_redis('Redis test', ['server' => $config->test_server]);
+        $configuration = array('server' => $config->test_server);
+        if (!empty($config->test_serializer)) {
+            $configuration['serializer'] = $config->test_serializer;
+        }
+        $cache = new cachestore_redis('Redis test', $configuration);
         $cache->initialise($definition);
 
         return $cache;
@@ -491,4 +512,19 @@ class cachestore_redis extends cache_store implements cache_is_key_aware, cache_
     public static function ready_to_be_used_for_testing() {
         return defined('TEST_CACHESTORE_REDIS_TESTSERVERS');
     }
+
+    /**
+     * Gets an array of options to use as the serialiser.
+     * @return array
+     */
+    public static function config_get_serializer_options() {
+        $options = array(
+            Redis::SERIALIZER_PHP => get_string('serializer_php', 'cachestore_redis')
+        );
+
+        if (defined('Redis::SERIALIZER_IGBINARY')) {
+            $options[Redis::SERIALIZER_IGBINARY] = get_string('serializer_igbinary', 'cachestore_redis');
+        }
+        return $options;
+    }
 }

cache/stores/redis/settings.php

@@ -25,12 +25,27 @@
 defined('MOODLE_INTERNAL') || die();
 
 $settings->add(
-  new admin_setting_configtext(
-    'cachestore_redis/test_server',
-    get_string('test_server', 'cachestore_redis'),
-    get_string('test_server_desc', 'cachestore_redis'),
-    '',
-    PARAM_TEXT,
-    16
-  )
+    new admin_setting_configtext(
+        'cachestore_redis/test_server',
+        get_string('test_server', 'cachestore_redis'),
+        get_string('test_server_desc', 'cachestore_redis'),
+        '',
+        PARAM_TEXT,
+        16
+    )
 );
+
+$options = array(Redis::SERIALIZER_PHP => get_string('serializer_php', 'cachestore_redis'));
+
+if (defined('Redis::SERIALIZER_IGBINARY')) {
+    $options[Redis::SERIALIZER_IGBINARY] = get_string('serializer_igbinary', 'cachestore_redis');
+}
+
+$settings->add(new admin_setting_configselect(
+        'cachestore_redis/test_serializer',
+        get_string('test_serializer', 'cachestore_redis'),
+        get_string('test_serializer_desc', 'cachestore_redis'),
+        0,
+        $options
+    )
+);