extern size_t dsi_stream_read (DSI *, void *, const size_t);
extern int dsi_stream_send (DSI *, void *, size_t);
extern int dsi_stream_receive (DSI *, void *, const size_t, size_t *);
extern size_t dsi_stream_read (DSI *, void *, const size_t);
extern int dsi_stream_send (DSI *, void *, size_t);
extern int dsi_stream_receive (DSI *, void *, const size_t, size_t *);