ringbuf.h
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上传日期:2007-06-06
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- /* ***** BEGIN LICENSE BLOCK *****
- * Version: RCSL 1.0/RPSL 1.0
- *
- * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved.
- *
- * The contents of this file, and the files included with this file, are
- * subject to the current version of the RealNetworks Public Source License
- * Version 1.0 (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the RealNetworks Community Source License Version 1.0
- * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl,
- * in which case the RCSL will apply. You may also obtain the license terms
- * directly from RealNetworks. You may not use this file except in
- * compliance with the RPSL or, if you have a valid RCSL with RealNetworks
- * applicable to this file, the RCSL. Please see the applicable RPSL or
- * RCSL for the rights, obligations and limitations governing use of the
- * contents of the file.
- *
- * This file is part of the Helix DNA Technology. RealNetworks is the
- * developer of the Original Code and owns the copyrights in the portions
- * it created.
- *
- * This file, and the files included with this file, is distributed and made
- * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
- * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- *
- * Technology Compatibility Kit Test Suite(s) Location:
- * http://www.helixcommunity.org/content/tck
- *
- * Contributor(s):
- *
- * ***** END LICENSE BLOCK ***** */
- #ifndef _RINGBUF_H_
- #define _RINGBUF_H_
- ///////////////////////////////////////////////////////////////////////////////
- // Class: CIHXRingBuffer
- // Purpose: An IHXBuffer based circular buffer class
- // Author: cts
- ///////////////////////////////////////////////////////////////////////////////
- class CIHXRingBuffer : public IHXBuffer
- {
- public:
- ///////////////////////////////////////////////////////////////////////////
- // Function: CIHXRingBuffer
- // Purpose: Constructor that allocates a ring buffer and allocates
- // space for data wrapping before the actual buffer. The
- // buffer looks like this |Wrap Bytes__|Buffer_______________|
- //
- // Params: pClassFactory is the Real COM class factory pointer
- // ulBufSize is the size of the ring buffer
- // ulWrapSize is the size of the wrap data before the buffer
- // Author: cts
- ///////////////////////////////////////////////////////////////////////////
- CIHXRingBuffer(IHXCommonClassFactory *pClassFactory,
- UINT32 ulBufSize,
- UINT32 ulWrapSize);
- ~CIHXRingBuffer();
- ///////////////////////////////////////////////////////////////////////////
- // IUnknown methods
- ///////////////////////////////////////////////////////////////////////////
- STDMETHOD(QueryInterface) (THIS_
- REFIID riid,
- void** ppvObj);
- STDMETHOD_(ULONG32,AddRef) (THIS);
- STDMETHOD_(ULONG32,Release) (THIS);
-
- ///////////////////////////////////////////////////////////////////////////
- // IHXBuffer methods
- ///////////////////////////////////////////////////////////////////////////
- STDMETHOD(Get) (THIS_ REF(UCHAR*) pData,
- REF(ULONG32) ulLength);
- STDMETHOD(Set) (THIS_ const UCHAR* pData,
- ULONG32 ulLength);
- STDMETHOD(SetSize) (THIS_ ULONG32 ulLength);
- STDMETHOD_(ULONG32,GetSize) (THIS);
- STDMETHOD_(UCHAR*,GetBuffer)(THIS);
-
- ///////////////////////////////////////////////////////////////////////////
- // Function: Reset
- // Purpose: Flushes the buffer and resets all variables.
- // Author: cts
- ///////////////////////////////////////////////////////////////////////////
- void Reset();
- ///////////////////////////////////////////////////////////////////////////
- // Function: CopyData
- // Purpose: Copies data to the next write position of the ring buffer.
- // This function handles buffer wrapping.
- // Params: pData is data to copy into the buffer
- // ulBytes is the amount of data to copy
- // Returns: The amount of data copied. If return is less than ulBytes
- // the buffer is full.
- // Author: cts
- ///////////////////////////////////////////////////////////////////////////
- UINT32 CopyData(UCHAR *pData, UINT32 ulBytes);
-
- ///////////////////////////////////////////////////////////////////////////
- // Function: AdvanceRead
- // Purpose: Advances the read pointer in the buffer handling wrapping.
- // Params: ulBytes is number of bytes to advance the read pointer
- // Author: cts
- ///////////////////////////////////////////////////////////////////////////
- void AdvanceRead(UINT32 ulBytes);
- ///////////////////////////////////////////////////////////////////////////
- // Function: DecrementRead
- // Purpose: Decrements the read pointer in the buffer.
- // Params: ulBytes is number of bytes to decrement the read pointer
- // Author: cts
- ///////////////////////////////////////////////////////////////////////////
- void DecrementRead(UINT32 ulBytes);
- ///////////////////////////////////////////////////////////////////////////
- // Function: GetReadPointer
- // Purpose: Gives Access to data by supplying the read pointer and
- // its size. Its size denotes how many bytes until the end
- // of the buffer.
- // Params: ulBytes will be the size of the read pointer
- // Returns: The read pointer
- // Author: cts
- ///////////////////////////////////////////////////////////////////////////
- UCHAR* GetReadPointer(UINT32 &ulBytes);
- ///////////////////////////////////////////////////////////////////////////
- // Function: Wrap
- // Purpose: Move the data from the current read postion to the wrap
- // area before the buffer and set the read pointer to that
- // position.
- //
- // Params: nOldBytes is the amount of bytes before your current read
- // pointer you want to preserve in the wrap.
- // Author: cts
- ///////////////////////////////////////////////////////////////////////////
- void Wrap(UINT32 ulOldBytes=0);
- // Status functions
- HX_RESULT GetError() {return m_ulError;}
- UINT32 GetBytesWritten() {return m_ulBytesWritten;}
- UINT32 GetBytesRead() {return m_ulBytesRead;}
- UINT32 GetBufferSize() {return m_ulBufSize;}
- UINT32 GetGuardSize() {return m_ulGuardSize;}
-
- UINT32 GetBytesInBuffer() {return m_ulBytesWritten - m_ulBytesRead;}
- UINT32 GetFreeBufferSpace() {return m_ulBufSize - GetBytesInBuffer();}
- UINT32 GetPrevBytes() {return m_ulRead - m_ulVBufBegin;}
- private:
- LONG32 m_lRefCount;
- UCHAR *m_pBuffer;
- union {UCHAR *m_pBufBegin; PTR_INT m_ulBufBegin;};
- union {UCHAR *m_pBufEnd; PTR_INT m_ulBufEnd;};
- union {UCHAR *m_pWrite; PTR_INT m_ulWrite;};
- union {UCHAR *m_pRead; PTR_INT m_ulRead;};
- union {UCHAR *m_pVBufBegin;PTR_INT m_ulVBufBegin;};
- UINT32 m_ulBytesWritten,
- m_ulBytesRead,
- m_ulBufSize,
- m_ulGuardSize;
- IHXBuffer *m_pIhxBuffer;
- HX_RESULT m_ulError;
- };
- #endif