/* Max length of remote pathname */
#define MXRIONAME 256

/* Size of RIO chunk transferred at a time */
#define MXRIOBYTES (1024*1024)

/* message types interchanged between this code and the server */
#define RIOHEADER 0x01
#define RIOCTS    0x02
#define RIODATA   0x03
#define RIOSTATUS 0x04
#define RIOACK    0x05
#define RIOPING   0x06
#define RIOEXIT   0xff

/* Fixed ports to try - should be list. */
#define GMCLIENTPORT 4
#define GMSERVERPORT 5

/* A generic message for RIOCTS or RIOSTATUS.  */
typedef struct {
	unsigned type;     /* one of the above defined types */
	int status;        /* interpretation depends on message type */
} RioMessage_t;

/* RIOHEADER message. 
* This information needs to be passed to the server for a write/read */
typedef struct {
	unsigned type;
	struct {
		int ireadwrite;
		unsigned nbytes;
#ifdef _WIN32
		__int64 offset;
#else
		unsigned offset;
#endif
		char name[MXRIONAME];
	} rio;
} RioHeader_t;

/* A data message will move on the low priority channel and hence needs 
* no other header information... so RIODATA is untagged.
*/

/* This is the client/server data interchange logic:
*
* ==============================
* write( ... node, addr, nbytes )
*
* ==CLIENT==           ==SERVER==
*
* RIOHEADER  --------> open file, error check
* copy first buffer
* to Riobuffer
* RIOCTS     <-------- ready to write
* send buffer  ------> RIODATA
* copy next            write buffer to file
* RIOCTS     <-------- ready 
* send buffer  ------> RIODATA
* no next to copy      write buffer to file
* RIOSTATUS  <-------- close file
* return status
*
* ==============================
* read( ... node, addr, nbytes )
*
* ==CLIENT==           ==SERVER==
*
* RIOHEADER  ---------> openfile, error check
*                         read first buffer
* ready for  ---------> RIOCTS
* RIODATA    <--------- send buffer, read next
* copy buffer    
*  to addr   ---------> RIOCTS
* RIODATA    <--------- send buffer, no next
* copy buffer             to read.
*  to addr
* finished   ---------> RIOCTS
* RIOSTATUS  <--------- no more bytes; close file
* return status
*
*/