io/source/stm/streamhelper.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 // Save NDEBUG state
  21 #ifdef NDEBUG
  22 #define STREAMHELPER_HXX_HAD_NDEBUG
  23 #undef NDEBUG
  24 #endif
  25
  26 #if OSL_DEBUG_LEVEL == 0
  27 #define NDEBUG
  28 #endif
  29 #include <assert.h>
  30
  31 #define Max( a, b )     (((a)>(b)) ? (a) : (b) )
  32 #define Min( a, b )     (((a)<(b)) ? (a) : (b) )
  33
  34 namespace io_stm {
  35
  36 class I_FIFO_OutOfBoundsException :
  37                 public Exception
  38 {};
  39
  40 class I_FIFO_OutOfMemoryException :
  41                 public Exception
  42 {};
  43
  44 class I_FIFO
  45 {
  46 public:
  47
  48
  49     virtual void    write( const Sequence<sal_Int8> &) throw( I_FIFO_OutOfMemoryException,
  50                                                               I_FIFO_OutOfBoundsException )=0;
  51
  52     virtual void    read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead )
  53                                                        throw( I_FIFO_OutOfBoundsException )=0;
  54     virtual void    skip( sal_Int32 nBytesToSkip )
  55                                                        throw( I_FIFO_OutOfBoundsException )=0;
  56     virtual sal_Int32   getSize() const throw(  )  =0;
  57     virtual void    shrink() throw() = 0;
  58
  59     virtual ~I_FIFO() {};
  60 };
  61
  62
  63 class IRingBuffer_OutOfBoundsException :
  64                 public Exception
  65 {};
  66
  67 class IRingBuffer_OutOfMemoryException :
  68                 public Exception
  69 {};
  70
  71 class IRingBuffer
  72 {
  73 public:
  74     /***
  75     * overwrites data at given position. Size is automatically extended, when
  76     * data is written beyond end.
  77     *
  78     ***/
  79
  80     virtual void    writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &)
  81         throw( IRingBuffer_OutOfMemoryException,
  82                IRingBuffer_OutOfBoundsException )=0;
  83     virtual void    readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const
  84         throw( IRingBuffer_OutOfBoundsException )=0;
  85     virtual sal_Int32   getSize() const throw(  )  =0;
  86     virtual void    forgetFromStart( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException)=0;
  87     virtual void    forgetFromEnd( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException)=0;
  88     virtual void    shrink() throw() = 0;
  89     virtual ~IRingBuffer() {};
  90 };
  91
  92
  93 class MemRingBuffer :
  94         public IRingBuffer
  95 {
  96 public:
  97     MemRingBuffer();
  98     virtual ~MemRingBuffer();
  99
 100     virtual void    writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &)
 101                                                     throw(  IRingBuffer_OutOfMemoryException,
 102                                                                 IRingBuffer_OutOfBoundsException );
 103     virtual void    readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const
 104                                                     throw( IRingBuffer_OutOfBoundsException );
 105     virtual sal_Int32   getSize() const throw(  );
 106     virtual void    forgetFromStart( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException);
 107     virtual void    forgetFromEnd( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException);
 108
 109     virtual void shrink() throw();
 110
 111 private:
 112
 113     void resizeBuffer( sal_Int32 nMinSize ) throw( IRingBuffer_OutOfMemoryException );
 114     inline void checkInvariants()
 115     {
 116         assert( m_nBufferLen >= 0 );
 117         assert( m_nOccupiedBuffer >= 0 );
 118         assert( m_nOccupiedBuffer <= m_nBufferLen );
 119         assert( m_nStart >= 0 );
 120         assert( 0 == m_nStart || m_nStart < m_nBufferLen );
 121     }
 122
 123     sal_Int8    *m_p;
 124     sal_Int32   m_nBufferLen;
 125     sal_Int32   m_nStart;
 126     sal_Int32   m_nOccupiedBuffer;
 127 };
 128
 129
 130 class MemFIFO :
 131     public  I_FIFO,
 132     private MemRingBuffer
 133 {
 134 public:
 135     virtual void    write( const Sequence<sal_Int8> &) throw( I_FIFO_OutOfMemoryException,
 136                                                               I_FIFO_OutOfBoundsException );
 137     virtual void    read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead )
 138                                                        throw( I_FIFO_OutOfBoundsException );
 139     virtual void    skip( sal_Int32 nBytesToSkip ) throw( I_FIFO_OutOfBoundsException );
 140     virtual sal_Int32   getSize()  const throw(  )
 141                         { return MemRingBuffer::getSize(); }
 142     virtual void    shrink() throw()
 143                         { MemRingBuffer::shrink(); }
 144
 145 };
 146
 147 // Restore NDEBUG state
 148 #ifdef STREAMHELPER_HXX_HAD_NDEBUG
 149 #define NDEBUG
 150 #else
 151 #undef NDEBUG
 152 #endif
 153
 154 }
 155
 156 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */