ringbuf.hpp

ARM9基于WINDOWSCE的BSP源代码

//
// Copyright (c) Microsoft Corporation.  All rights reserved.
//
//
// Use of this source code is subject to the terms of the Microsoft end-user
// license agreement (EULA) under which you licensed this SOFTWARE PRODUCT.
// If you did not accept the terms of the EULA, you are not authorized to use
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/* -*-C-*-
 *
 * ringbuf:
 * 
 * Class implementing a simple ring buffer
 *
 * Release Status:OS005-SW-70002-r0p0-00REL0
 * $Copyright: 
 * ----------------------------------------------------------------
 * This confidential and proprietary software may be used only as
 * authorised by a licensing agreement from ARM Limited
 *   (C) COPYRIGHT 2004 ARM Limited
 *       ALL RIGHTS RESERVED
 * The entire notice above must be reproduced on all authorised
 * copies and copies may only be made to the extent permitted
 * by a licensing agreement from ARM Limited.
 * ----------------------------------------------------------------
 * File:     ringbuf.hpp,v
 * Revision: 1.1
 * ----------------------------------------------------------------
 * $
 */
#ifndef ringbuf_hpp
#define ringbuf_hpp

class RingBuf
{
  public:
    RingBuf(void)
    {
        fillindex = drainindex = 0;
        indexmask = 0x07;
        buffer = new unsigned int[8];
    }

    ~RingBuf(void)
    {
        delete[] buffer;
    }

    inline bool add(unsigned int value)
    {
        if (fillindex != ((drainindex - 1) & indexmask))
        {
            buffer[fillindex] = value;

            ++fillindex;
            fillindex &= indexmask;

            return true;
        }
        else
            return false;
    }

    inline bool extract(unsigned int *value)
    {
        if (drainindex != fillindex)
        {
            *value = buffer[drainindex];

            ++drainindex;
            drainindex &= indexmask;

            return true;
        }
        else
            return false;
    }

    inline bool peek(unsigned int *value)
    {
        if (drainindex != fillindex)
        {
            *value = buffer[drainindex];

            return true;
        }
        else
            return false;
    }

    inline void advancedrain(void)
    {
        if (drainindex != fillindex)
        {
            ++drainindex;
            drainindex &= indexmask;
        }
    }

    inline bool empty(void)
    {
        return fillindex == drainindex;
    }

  private:
    unsigned int fillindex;
    unsigned int drainindex;
    unsigned int *buffer;
    unsigned int indexmask;
};

#endif /* ndef ringbuf_hpp */

/* EOF ringbuf.hpp */