iointernal.h

/*NB_REVISION*/
 
/*NB_COPYRIGHT*/
 
#ifndef _NB_IOINTERNALS_H
#define _NB_IOINTERNALS_H
 
class FDInfo; //Forward declration
 
 
extern int null_read(int fd, char *buf, int nbytes);
extern int null_write(int fd, const char *buf, int nbytes);
extern int null_close(int fd);
extern FDInfo unknowninfo;
 
/*
 * I/O Expansion Structure
 *    read                    - read function
 *    write                   - write function
 *    close                   - close function
 *    peek                    - peek function peeks at next char
 *    pInfoStruct             -A class with functions to get info about this thing.
 *    extra                   - void * to stash things in
 *
 *    Notes:
 *       Expanded routines for library read, write and close
 */
struct IoExpandStruct
{
    int (*read)(int fd, char *buf, int nbytes);
    int (*write)(int fd, const char *buf, int nbytes);
    int (*close)(int fd);
    int (*peek)(int fd, char *buf);
    FDInfo *pInfoStruct;
    void *extra;
 
    //Since pInfoStruct is a new memeber and its really important this gets set or left as null
    //We are adding a constructor to make sure its zero by default.
inline  IoExpandStruct( int (*io_read)(int fd, char *buf, int nbytes)=null_read,
                    int (*io_write)(int fd, const char *buf, int nbytes)=null_write,
                    int (*io_close)(int fd)=null_close,
                    int (*io_peek)(int fd, char *buf)=0,
                    FDInfo *io_pInfo=&unknowninfo,
                    void *io_extra=0)
    {
        read=io_read;
        write=io_write;
        close=io_close;
        peek=io_peek;
        pInfoStruct=io_pInfo;
        extra=io_extra;
    }
 
 
} __attribute__((packed));
 
/****************************************************************************
 
   Acquire/Release/Access expansion file descriptor
 
      Parameters:
         extra_data        - Control data structure beginning with
                              IoFrameworkStruct
         pFuncs            - Expanded I/O routines
 
         fd                - Expanded file descriptor
 
      Return:
         Acquired fd > EXTRA_IO_OFFSET OK, else -1 for none
 
 ****************************************************************************/
 
int GetExtraFD(void *extra_data, struct IoExpandStruct *pFuncs);
 
IoExpandStruct *GetIoExpandStruct(int fd);
 
void *GetExtraData(int fd);
 
void FreeExtraFd(int fd);
 
int GetFreeExtraFDCount();
 
int GetFreeSocketCount(void);
 
/*
  ***************************************************************************
 
    I/O subsystem notification support for use by expanded I/O routines
 
       Parameters:
          fd                - Expanded file descriptor
 
       Return:
          None
 
  ***************************************************************************
  */
void SetDataAvail(int fd);
void ClrDataAvail(int fd);
 
void SetWriteAvail(int fd);
void ClrWriteAvail(int fd);
 
void SetHaveError(int fd);
void ClrHaveError(int fd);
 
void Closing(int fd);
 
 
//Class designed to get info about individual FD's
class FDInfo
{
    const char * pName;
public:
    FDInfo (const char * name=0)
        : pName(name)
    {}
 
    virtual bool IsMyFd(int fd)
    {
        IoExpandStruct * pio=GetIoExpandStruct(fd);
        if(pio && (pio->pInfoStruct==this))
            return true;
        return false;
    }
 
    virtual const char * GetFdTypeName(int fd);
 
    virtual int GetFdBelow(int fd);
    FDInfo *    GetInfoBelow(int fd);
 
    virtual int RxBuffer_SpaceUsed(int fd);
    virtual int RxBuffer_SpaceAvail(int fd);
    virtual int TxBuffer_SpaceUsed(int fd);
    virtual int TxBuffer_SpaceAvail(int fd);
 
    virtual bool AllTxSent(int fd);
 
    virtual int  RxBuffer_GetMaxSize(int fd);
    virtual int  RxBuffer_SetMaxSize(int fd, int space);
    virtual int  TxBuffer_GetMaxSize(int fd);
    virtual int  TxBuffer_SetMaxSize(int fd, int space);
 
    //Should this socket flush the whole content stack on each write.
    virtual void SetFlush(int fd,bool bDoFlush){};
 
    //Run IOCTL on this fd
    virtual int doIoctl(int fd, int cmd) {return -1;};
};
#endif