hxbuffer.h

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/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: hxbuffer.h,v 1.6.32.3 2004/07/09 01:45:51 hubbe Exp $
 * 
 * Portions Copyright (c) 1995-2004 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 (the "RPSL") available at
 * http://www.helixcommunity.org/content/rpsl unless you have licensed
 * the file under the current version of the RealNetworks Community
 * Source License (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.
 * 
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License Version 2 or later (the
 * "GPL") in which case the provisions of the GPL are applicable
 * instead of those above. If you wish to allow use of your version of
 * this file only under the terms of the GPL, and not to allow others
 * to use your version of this file under the terms of either the RPSL
 * or RCSL, indicate your decision by deleting the provisions above
 * and replace them with the notice and other provisions required by
 * the GPL. If you do not delete the provisions above, a recipient may
 * use your version of this file under the terms of any one of the
 * RPSL, the RCSL or the GPL.
 * 
 * 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 _HXBUFFER_H_
#define _HXBUFFER_H_

#include "ihxpckts.h"
#include "hxvalue.h"
//#include "hxheap.h"
#include "hxstring.h"

// This determines the length of the built in buffer that is used if the
// data length is small enough, to save us from allocating so many little
// pieces of data.
#define PnBufferShort
#ifdef PnBufferShort
const int MaxPnbufShortDataLen = 15;
#endif

#define NUM_ALLOCATION_EACH_TIME	25
/****************************************************************************
 * 
 *	Class:
 *
 *		CHXBuffer
 *
 *	Purpose:
 *
 *		PN implementation of a basic buffer.
 *
 */
class CHXBuffer 
    : public IHXBuffer
{
protected:

        LONG32					m_lRefCount;
	ULONG32				        m_ulAllocLength;
 	BOOL m_bJustPointToExistingData;

#if !defined(HELIX_CONFIG_NOSTATICS)
        // Interface for optional allocator
        static 	IMalloc*		m_zMallocInterface;
#endif

        // number of CHXBuffer allocated at a time to be placed in freeStore
        static 	CHXBuffer*		s_pFreeStore;
        static 	const int		s_iBufferChunk;	

        virtual ~CHXBuffer();

        BOOL FreeWithMallocInterface() const;

#ifdef PnBufferShort
    // buffer for small amounts of data
    //UCHAR m_ShortData[MaxPnbufShortDataLen + 1];
#endif

        enum { BigDataTag = 0xEE };
        
        union
        {
            struct 
            {
	            UCHAR*					m_pData;
	            ULONG32					m_ulLength;
	            unsigned char				m_FreeWithMallocInterfaceIfAvail;
            } m_BigData;

            UCHAR m_ShortData[MaxPnbufShortDataLen + 1];
        };

        bool IsShort() const;
        HX_RESULT SetSize(ULONG32 ulLength, BOOL copyExistingData);
    
        UCHAR* Allocate(UINT32 size) const;
        UCHAR* Reallocate(UCHAR*, UINT32 oldSize, UINT32 newSize) const;
        void Deallocate(UCHAR*) const;

        PRIVATE_DESTRUCTORS_ARE_NOT_A_CRIME

public:
        CHXBuffer();
        CHXBuffer(UCHAR* pData, UINT32 ulLength, BOOL bOwnBuffer = TRUE);

#if 0
#ifndef __MWERKS__
#if defined (_DEBUG) && defined (_WIN32) && 0
         void * operator new(
        unsigned int,
        int,
        const char *,
        int
        );
#else
        void * 		operator	new (size_t size);
#endif /*defined (_DEBUG) && defined (_WIN32) */
        void		operator	delete(void *p, size_t size);
#endif /*__MWERKS__*/
#endif /*0*/

        inline CHXBuffer& operator=(const char* psz);
        inline CHXBuffer& operator=(const unsigned char* psz);
        inline CHXBuffer& operator=(const CHXString &str);
        /*
         *	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);


public:
    static HX_RESULT FromCharArray
    (
        const char* szIn, 
        IHXBuffer** ppbufOut
    );
    static HX_RESULT FromCharArray
    (
        const char* szIn, 
        UINT32 ulLength, 
        IHXBuffer** ppbufOut
    );
    static void SetAllocator(IMalloc* pMalloc);
    static void ReleaseAllocator();
};

CHXBuffer& CHXBuffer::operator=(const char* psz)
{
        Set((const unsigned char*)psz, strlen(psz)+1);
        return(*this);
}

CHXBuffer& CHXBuffer::operator=(const unsigned char* psz)
{
        Set(psz, strlen((const char*)psz)+1);
        return(*this);
}

CHXBuffer& CHXBuffer::operator=(const CHXString& str)
{
        Set((const unsigned char*)(const char *)str, str.GetLength()+1);
        return(*this);
}


// This class was created in order to be able to have a buffer that consists of
// a subset of another existing buffer without allocating any new data or 
// copying data over. The way to use this class is to instantiate it with 3 
// parameters: 
// 1) A pointer to the superset buffer, 
// 2) The pointer to the point in the the buffer that represents the start of 
//    the subset buffer, and 
// 3) The length of the subset buffer.
//
class CHXBufferFragment : public CHXBuffer
{
public :
    CHXBufferFragment(IHXBuffer * pWrappedBuffer, UCHAR* pModFrameStart, ULONG32 ulFragLen) : CHXBuffer( pModFrameStart, ulFragLen, FALSE ), m_pHXBufferPointedTo(pWrappedBuffer){ if(pWrappedBuffer) {pWrappedBuffer->AddRef();} };
    ~CHXBufferFragment(){ HX_RELEASE(m_pHXBufferPointedTo);}

protected :
    IHXBuffer * m_pHXBufferPointedTo;
};

#endif