xref: /trunk/main/io/source/stm/streamhelper.hxx (revision 914d351e5f5b84e4342a86d6ab8d4aca7308b9bd)

/**************************************************************
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 *************************************************************/



// Save NDEBUG state
#ifdef NDEBUG
#define STREAMHELPER_HXX_HAD_NDEBUG
#undef NDEBUG
#endif

#if OSL_DEBUG_LEVEL == 0
#define NDEBUG
#endif
#include <assert.h>

#define Max( a, b )     (((a)>(b)) ? (a) : (b) )
#define Min( a, b )     (((a)<(b)) ? (a) : (b) )

namespace io_stm {

class IFIFO_OutOfBoundsException :
                public Exception
{};

class IFIFO_OutOfMemoryException :
                public Exception
{};

class IFIFO
{
public:


    virtual void    write( const Sequence<sal_Int8> &) throw( IFIFO_OutOfMemoryException,
                                                              IFIFO_OutOfBoundsException )=0;

    virtual void    read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead )
                                                    throw( IFIFO_OutOfBoundsException )=0;
    virtual void    skip( sal_Int32 nBytesToSkip )
                                        throw( IFIFO_OutOfBoundsException )=0;
    virtual sal_Int32   getSize() const throw(  )  =0;
    virtual void    shrink() throw() = 0;

    virtual ~IFIFO() {};
};


class IRingBuffer_OutOfBoundsException :
                public Exception
{};

class IRingBuffer_OutOfMemoryException :
                public Exception
{};

class IRingBuffer
{
public:
    /***
    * overwrites data at given position. Size is automatically extended, when
    * data is written beyond end.
    *
    ***/

    virtual void    writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &)
        throw( IRingBuffer_OutOfMemoryException,
               IRingBuffer_OutOfBoundsException )=0;
    virtual void    readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const
        throw( IRingBuffer_OutOfBoundsException )=0;
    virtual sal_Int32   getSize() const throw(  )  =0;
    virtual void    forgetFromStart( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException)=0;
    virtual void    forgetFromEnd( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException)=0;
    virtual void    shrink() throw() = 0;
    virtual ~IRingBuffer() {};
};


class MemRingBuffer :
        public IRingBuffer
{
public:
    MemRingBuffer();
    virtual ~MemRingBuffer();

    virtual void    writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &)
                                                    throw(  IRingBuffer_OutOfMemoryException,
                                                                IRingBuffer_OutOfBoundsException );
    virtual void    readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const
                                                    throw( IRingBuffer_OutOfBoundsException );
    virtual sal_Int32   getSize() const throw(  );
    virtual void    forgetFromStart( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException);
    virtual void    forgetFromEnd( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException);

    virtual void shrink() throw();

private:

    void resizeBuffer( sal_Int32 nMinSize ) throw( IRingBuffer_OutOfMemoryException );
    inline void checkInvariants()
    {
        assert( m_nBufferLen >= 0 );
        assert( m_nOccupiedBuffer >= 0 );
        assert( m_nOccupiedBuffer <= m_nBufferLen );
        assert( m_nStart >= 0 );
        assert( 0 == m_nStart || m_nStart < m_nBufferLen );
    }

    sal_Int8    *m_p;
    sal_Int32   m_nBufferLen;
    sal_Int32   m_nStart;
    sal_Int32   m_nOccupiedBuffer;
};


class MemFIFO :
        public  IFIFO,
        private MemRingBuffer
{
public:
    virtual void    write( const Sequence<sal_Int8> &) throw( IFIFO_OutOfMemoryException,
                                                              IFIFO_OutOfBoundsException );
    virtual void    read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead )
                                                    throw( IFIFO_OutOfBoundsException );
    virtual void    skip( sal_Int32 nBytesToSkip ) throw( IFIFO_OutOfBoundsException );
    virtual sal_Int32   getSize()  const throw(  )
                        { return MemRingBuffer::getSize(); }
    virtual void    shrink() throw()
                        { MemRingBuffer::shrink(); }

};

// Restore NDEBUG state
#ifdef STREAMHELPER_HXX_HAD_NDEBUG
#define NDEBUG
#else
#undef NDEBUG
#endif

}