GmCharRingBuffer.hpp

#ifndef GMCHARRINGBUFFER_HPP_
#define GMCHARRINGBUFFER_HPP_
 
namespace Geometrics
{
 
   #define GM_CHAR_RING_BUFFER_OK                    0
   #define GM_CHAR_RING_BUFFER_NO_BUFFER             1
   #define GM_CHAR_RING_BUFFER_INVALID_INDEX         2
   #define GM_CHAR_RING_BUFFER_NO_ROOM               3
   #define GM_CHAR_RING_BUFFER_FAILURE               4
   #define GM_CHAR_RING_BUFFER_OVERRUN_OVERWROTE     5
   #define GM_CHAR_RING_BUFFER_OVERRUN_NO_WRITE      6
   #define GM_CHAR_RING_BUFFER_EMPTY                 7
   #define GM_CHAR_RING_BUFFER_NULL_DESTINATION      8
   #define GM_CHAR_RING_BUFFER_NO_BYTES              9
 
 
   // Initially, this is FIFO only.
   // This class has no concurrency control.  That must occur
   //   in the clients of this class.
   // Would be nice to add priority, so that for purposes
   //    such as task switching,
   //    we could put higher-priority items in the buffer.
   class GmCharRingBuffer
   {
   public:
      GmCharRingBuffer         (int64_t     iBufferSize,
                                void        *buffer);
      ~GmCharRingBuffer        ();
 
     int  Read                 (void        *dest,
                                int64_t     count);
     int  Write                (void        *source,
                                int64_t     count);
     int64_t  BufferSize       () { return  mBufferSize; }
     bool     IsFull           ();
     int      SetEmpty         ();
     bool     HasData          () { return  (mHead != mTail); }
     bool     IsEmpty          () { return  (mHead == mTail); }
 
     int      ReadAt           (void*    dest,
                                int64_t    index,
                                int64_t    size);
     int      EraseNext        (int64_t    sizeToErase);
     int64_t  NextWritePosition ();
     int64_t  BytesAvailable    ();
     int64_t  BytesAvailableAt  (int64_t index);
     int64_t  FreeSpace         ();
     int      SeekRead          (int64_t nextRead);
     
   public:
     int64_t      mHead,
                  mTail,
                  mBufferSize;
     void        *mBuffer;
   };
 
 
 
 
}
#endif /* GMCHARRINGBUFFER_HPP_ */