+ return fwrite($this->getPointer(), $dataStream, strlen($dataStream));
+ }
+
+ /**
+ * Rewinds to the beginning of the file
+ *
+ * @return void
+ */
+ public function rewind () {
+ // Rewind the pointer
+ assert(rewind($this->getPointer()) === 1);
+ }
+
+ /**
+ * Seeks to given position
+ *
+ * @param $seekPosition Seek position in file
+ * @param $whence "Seek mode" (see http://de.php.net/fseek)
+ * @return void
+ */
+ public function seek ($seekPosition, $whence = SEEK_SET) {
+ // Move the file pointer
+ assert(fseek($this->getPointer(), $seekPosition, $whence) === 0);