Write to session in batch at the end of the request

lib/private/session/cryptosessiondata.php

 	protected $passphrase;
 	/** @var array */
 	protected $sessionValues;
+	/** @var bool */
+	protected $isModified = false;
 	CONST encryptedSessionName = 'encrypted_session_data';
 
 	/**
 		$this->initializeSession();
 	}
 
+	/**
+	 * Close session if class gets destructed
+	 */
+	public function __destruct() {
+		$this->close();
+	}
+
 	protected function initializeSession() {
 		$encryptedSessionData = $this->session->get(self::encryptedSessionName);
 		try {
 	 */
 	public function set($key, $value) {
 		$this->sessionValues[$key] = $value;
-		$encryptedValue = $this->crypto->encrypt(json_encode($this->sessionValues), $this->passphrase);
-		$this->session->set(self::encryptedSessionName, $encryptedValue);
+		$this->isModified = true;
 	}
 
 	/**
 	 * @return string|null Either the value or null
 	 */
 	public function get($key) {
-
 		if(isset($this->sessionValues[$key])) {
 			return $this->sessionValues[$key];
 		}
 	 * @param string $key
 	 */
 	public function remove($key) {
+		$this->isModified = true;
 		unset($this->sessionValues[$key]);
 		$this->session->remove(self::encryptedSessionName);
 	}
 	 */
 	public function clear() {
 		$this->sessionValues = [];
+		$this->isModified = true;
 		$this->session->clear();
 	}
 
 	/**
-	 * Close the session and release the lock
+	 * Close the session and release the lock, also writes all changed data in batch
 	 */
 	public function close() {
+		if($this->isModified) {
+			$encryptedValue = $this->crypto->encrypt(json_encode($this->sessionValues), $this->passphrase);
+			$this->session->set(self::encryptedSessionName, $encryptedValue);
+			$this->isModified = false;
+		}
 		$this->session->close();
 	}
 

lib/private/session/internal.php

  * @package OC\Session
  */
 class Internal extends Session {
+	/**
+	 * @param string $name
+	 * @throws \Exception
+	 */
 	public function __construct($name) {
 		session_name($name);
 		set_error_handler(array($this, 'trapError'));
 		}
 	}
 
-	public function __destruct() {
-		$this->close();
-	}
-
 	/**
 	 * @param string $key
 	 * @param integer $value

tests/lib/session/cryptowrappingtest.php

 		$this->instance = new CryptoSessionData($this->wrappedSession, $this->crypto, 'PASS');
 	}
 
-	public function testWrappingSet() {
-		$unencryptedValue = 'foobar';
-
-		$this->wrappedSession->expects($this->once())
-			->method('set')
-			->with('encrypted_session_data', $this->crypto->encrypt(json_encode(['encrypted_session_data' => $unencryptedValue])));
-		$this->instance->set('encrypted_session_data', $unencryptedValue);
-	}
-
 	public function testUnwrappingGet() {
 		$unencryptedValue = 'foobar';
 		$encryptedValue = $this->crypto->encrypt($unencryptedValue);