readInt16
Reads a 16-bit/2-byte value from @stream.
In order to get the correct byte order for this read operation, see g_data_input_stream_get_byte_order() and g_data_input_stream_set_byte_order().
Return
a signed 16-bit/2-byte value read from @stream or 0
if an error occurred.
Parameters
cancellable
optional #GCancellable object, null to ignore.