CircularBuffer.h++

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/* ---------------------------------------------------------------------------
   commonc++ - A C++ Common Class Library
   Copyright (C) 2005-2012  Mark A Lindner

   This file is part of commonc++.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   ---------------------------------------------------------------------------
*/

#ifndef __ccxx_CircularBuffer_hxx
#define __ccxx_CircularBuffer_hxx

#include <commonc++/Common.h++>
#include <commonc++/AbstractBuffer.h++>
#include <commonc++/IOException.h++>
#include <commonc++/MemoryBlock.h++>
#include <commonc++/Stream.h++>

#include <algorithm>
#include <cstdlib>
#include <cstring>

#ifdef CCXX_OS_POSIX
#include <sys/uio.h>
#endif

namespace ccxx {

template <typename T> class CircularBuffer : public AbstractBuffer<T>
{
  public:

  CircularBuffer(size_t size);

  ~CircularBuffer() throw();

  void clear() throw();

  virtual void setSize(size_t newSize);

  size_t write(const T *buf, size_t count) throw();

  size_t write(Buffer<T>& buffer, size_t count = 0) throw();

  size_t write(Stream& stream, size_t count = 0) throw(IOException);

  size_t read(T *buf, size_t count) throw();

  size_t read(Buffer<T>& buffer, size_t count = 0) throw();

  size_t read(Stream& stream, size_t count = 0) throw(IOException);

  size_t peek(const T &value, size_t maxlen, bool &found,
              bool resetPeek = true)
    throw();

  size_t fill(const T &value, size_t count) throw();

  size_t getReadExtent() const throw();

  size_t getWriteExtent() const throw();

  inline size_t getRemaining() const throw()
  { return(_avail); }

  inline size_t getPeekRemaining() const throw()
  { return(_peekAvail); }

  inline bool isEmpty() const throw()
  { return(_avail == 0); }

  inline bool isFull() const throw()
  { return(this->_size == _avail); }

  inline size_t getFree() const throw()
  { return(this->_size - _avail); }

  inline T *getReadPos() throw()
  { return(_readPos); }

  inline T *getWritePos() throw()
  { return(_writePos); }

  inline T *getPeekPos() throw()
  { return(_peekPos); }

  T *advanceReadPos(size_t count) throw();

  T *advanceWritePos(size_t count) throw();

  inline T *advanceReadPos() throw()
  { return(advanceReadPos(getReadExtent())); }

  inline T *advanceWritePos() throw()
  { return(advanceWritePos(getWriteExtent())); }

  T *advancePeekPos(size_t count) throw();

  void resetPeekPos() throw();

  bool isPartialWrite() const throw()
  { return(_writeShift > 0); }

  bool isPartialRead() const throw()
  { return(_readShift > 0); }

  private:

  T *_end;
  T *_readPos;
  T *_writePos;
  T *_peekPos;
  size_t _avail;
  size_t _peekAvail;
  size_t _readShift;
  size_t _writeShift;

  CCXX_COPY_DECLS(CircularBuffer);
};

#include <commonc++/CircularBufferImpl.h++>

typedef CircularBuffer<byte_t> CircularByteBuffer;
typedef CircularBuffer<char> CircularCharBuffer;

}; // namespace ccxx

#endif // __ccxx_CircularBuffer_hxx

/* end of header file */