$stream
$stream : resource
Stream resource.
Implementation of Horde_Stream that uses a PHP native string variable until a certain size is reached, at which point it converts storage to a PHP temporary stream.
NOTE: Do NOT use this class if it's possible that a stream_filter will need to be added to the stream by some client code. If the size of the data does not exceed max_memory there will be no stream to attach to.
$_string : \Horde_Stream_String
String stream object.