io/source/stm/streamhelper.hxx

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   9  * $RCSfile: streamhelper.hxx,v $
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  30
  31 // Save NDEBUG state
  32 #ifdef NDEBUG
  33 #define STREAMHELPER_HXX_HAD_NDEBUG
  34 #undef NDEBUG
  35 #endif
  36
  37 #if OSL_DEBUG_LEVEL == 0
  38 #define NDEBUG
  39 #endif
  40 #include <assert.h>
  41
  42 #define Max( a, b )     (((a)>(b)) ? (a) : (b) )
  43 #define Min( a, b )             (((a)<(b)) ? (a) : (b) )
  44
  45 namespace io_stm {
  46
  47 class IFIFO_OutOfBoundsException :
  48                 public Exception
  49 {};
  50
  51 class IFIFO_OutOfMemoryException :
  52                 public Exception
  53 {};
  54
  55 class IFIFO
  56 {
  57 public:
  58
  59
  60     virtual void        write( const Sequence<sal_Int8> &) throw( IFIFO_OutOfMemoryException,
  61                                                               IFIFO_OutOfBoundsException )=0;
  62
  63     virtual void        read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead )
  64                                                     throw( IFIFO_OutOfBoundsException )=0;
  65     virtual void        skip( sal_Int32 nBytesToSkip )
  66                                         throw( IFIFO_OutOfBoundsException )=0;
  67     virtual sal_Int32   getSize() const throw(  )  =0;
  68     virtual void        shrink() throw() = 0;
  69
  70     virtual ~IFIFO() {};
  71 };
  72
  73
  74 class IRingBuffer_OutOfBoundsException :
  75                 public Exception
  76 {};
  77
  78 class IRingBuffer_OutOfMemoryException :
  79                 public Exception
  80 {};
  81
  82 class IRingBuffer
  83 {
  84 public:
  85     /***
  86     * overwrites data at given position. Size is automatically extended, when
  87     * data is written beyond end.
  88     *
  89     ***/
  90
  91     virtual void        writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &)
  92         throw( IRingBuffer_OutOfMemoryException,
  93                IRingBuffer_OutOfBoundsException )=0;
  94     virtual void        readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const
  95         throw( IRingBuffer_OutOfBoundsException )=0;
  96     virtual sal_Int32   getSize() const throw(  )  =0;
  97     virtual void        forgetFromStart( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException)=0;
  98     virtual void        forgetFromEnd( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException)=0;
  99     virtual void        shrink() throw() = 0;
 100     virtual ~IRingBuffer() {};
 101 };
 102
 103
 104 class MemRingBuffer :
 105         public IRingBuffer
 106 {
 107 public:
 108     MemRingBuffer();
 109     virtual ~MemRingBuffer();
 110
 111     virtual void        writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &)
 112                                                     throw(      IRingBuffer_OutOfMemoryException,
 113                                                                 IRingBuffer_OutOfBoundsException );
 114     virtual void        readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const
 115                                                     throw( IRingBuffer_OutOfBoundsException );
 116     virtual sal_Int32   getSize() const throw(  );
 117     virtual void        forgetFromStart( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException);
 118     virtual void        forgetFromEnd( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException);
 119
 120     virtual void shrink() throw();
 121
 122 private:
 123
 124     void resizeBuffer( sal_Int32 nMinSize ) throw( IRingBuffer_OutOfMemoryException );
 125     inline void checkInvariants()
 126     {
 127         assert( m_nBufferLen >= 0 );
 128         assert( m_nOccupiedBuffer >= 0 );
 129         assert( m_nOccupiedBuffer <= m_nBufferLen );
 130         assert( m_nStart >= 0 );
 131         assert( 0 == m_nStart || m_nStart < m_nBufferLen );
 132     }
 133
 134     sal_Int8    *m_p;
 135     sal_Int32   m_nBufferLen;
 136     sal_Int32   m_nStart;
 137     sal_Int32   m_nOccupiedBuffer;
 138 };
 139
 140
 141 class MemFIFO :
 142         public  IFIFO,
 143         private MemRingBuffer
 144 {
 145 public:
 146     virtual void        write( const Sequence<sal_Int8> &) throw( IFIFO_OutOfMemoryException,
 147                                                               IFIFO_OutOfBoundsException );
 148     virtual void        read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead )
 149                                                     throw( IFIFO_OutOfBoundsException );
 150     virtual void        skip( sal_Int32 nBytesToSkip ) throw( IFIFO_OutOfBoundsException );
 151     virtual sal_Int32   getSize()  const throw(  )
 152                         { return MemRingBuffer::getSize(); }
 153     virtual void        shrink() throw()
 154                         { MemRingBuffer::shrink(); }
 155
 156 };
 157
 158 // Restore NDEBUG state
 159 #ifdef STREAMHELPER_HXX_HAD_NDEBUG
 160 #define NDEBUG
 161 #else
 162 #undef NDEBUG
 163 #endif
 164
 165 }