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 #ifndef INCLUDED_IO_SOURCE_STM_STREAMHELPER_HXX
  21 #define INCLUDED_IO_SOURCE_STM_STREAMHELPER_HXX
  22
  23 // Save NDEBUG state
  24 #ifdef NDEBUG
  25 #define STREAMHELPER_HXX_HAD_NDEBUG
  26 #undef NDEBUG
  27 #endif
  28
  29 #if OSL_DEBUG_LEVEL == 0
  30 #define NDEBUG
  31 #endif
  32 #include <assert.h>
  33
  34 #define Max( a, b )     (((a)>(b)) ? (a) : (b) )
  35 #define Min( a, b )     (((a)<(b)) ? (a) : (b) )
  36
  37 namespace io_stm {
  38
  39 class I_FIFO_OutOfBoundsException :
  40                 public Exception
  41 {};
  42
  43 class I_FIFO_OutOfMemoryException :
  44                 public Exception
  45 {};
  46
  47 class I_FIFO
  48 {
  49 public:
  50
  51
  52     virtual void    write( const Sequence<sal_Int8> &) throw( I_FIFO_OutOfMemoryException,
  53                                                               I_FIFO_OutOfBoundsException )=0;
  54
  55     virtual void    read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead )
  56                                                        throw( I_FIFO_OutOfBoundsException )=0;
  57     virtual void    skip( sal_Int32 nBytesToSkip )
  58                                                        throw( I_FIFO_OutOfBoundsException )=0;
  59     virtual sal_Int32   getSize() const throw(  )  =0;
  60     virtual void    shrink() throw() = 0;
  61
  62     virtual ~I_FIFO() {};
  63 };
  64
  65
  66 class IRingBuffer_OutOfBoundsException :
  67                 public Exception
  68 {};
  69
  70 class IRingBuffer_OutOfMemoryException :
  71                 public Exception
  72 {};
  73
  74 class IRingBuffer
  75 {
  76 public:
  77     /***
  78     * overwrites data at given position. Size is automatically extended, when
  79     * data is written beyond end.
  80     *
  81     ***/
  82
  83     virtual void    writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &)
  84         throw( IRingBuffer_OutOfMemoryException,
  85                IRingBuffer_OutOfBoundsException )=0;
  86     virtual void    readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const
  87         throw( IRingBuffer_OutOfBoundsException )=0;
  88     virtual sal_Int32   getSize() const throw(  )  =0;
  89     virtual void    forgetFromStart( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException)=0;
  90     virtual void    forgetFromEnd( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException)=0;
  91     virtual void    shrink() throw() = 0;
  92     virtual ~IRingBuffer() {};
  93 };
  94
  95
  96 class MemRingBuffer :
  97         public IRingBuffer
  98 {
  99 public:
 100     MemRingBuffer();
 101     virtual ~MemRingBuffer();
 102
 103     virtual void    writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &)
 104                                                     throw(  IRingBuffer_OutOfMemoryException,
 105                                                                 IRingBuffer_OutOfBoundsException ) SAL_OVERRIDE;
 106     virtual void    readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const
 107                                                     throw( IRingBuffer_OutOfBoundsException ) SAL_OVERRIDE;
 108     virtual sal_Int32   getSize() const throw(  ) SAL_OVERRIDE;
 109     virtual void    forgetFromStart( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException) SAL_OVERRIDE;
 110     virtual void    forgetFromEnd( sal_Int32 nBytesToForget ) throw(IRingBuffer_OutOfBoundsException) SAL_OVERRIDE;
 111
 112     virtual void shrink() throw() SAL_OVERRIDE;
 113
 114 private:
 115
 116     void resizeBuffer( sal_Int32 nMinSize ) throw( IRingBuffer_OutOfMemoryException );
 117     inline void checkInvariants()
 118     {
 119         assert( m_nBufferLen >= 0 );
 120         assert( m_nOccupiedBuffer >= 0 );
 121         assert( m_nOccupiedBuffer <= m_nBufferLen );
 122         assert( m_nStart >= 0 );
 123         assert( 0 == m_nStart || m_nStart < m_nBufferLen );
 124     }
 125
 126     sal_Int8    *m_p;
 127     sal_Int32   m_nBufferLen;
 128     sal_Int32   m_nStart;
 129     sal_Int32   m_nOccupiedBuffer;
 130 };
 131
 132
 133 class MemFIFO :
 134     public  I_FIFO,
 135     private MemRingBuffer
 136 {
 137 public:
 138     virtual void    write( const Sequence<sal_Int8> &) throw( I_FIFO_OutOfMemoryException,
 139                                                               I_FIFO_OutOfBoundsException ) SAL_OVERRIDE;
 140     virtual void    read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead )
 141                                                        throw( I_FIFO_OutOfBoundsException ) SAL_OVERRIDE;
 142     virtual void    skip( sal_Int32 nBytesToSkip ) throw( I_FIFO_OutOfBoundsException ) SAL_OVERRIDE;
 143     virtual sal_Int32   getSize()  const throw(  ) SAL_OVERRIDE
 144                         { return MemRingBuffer::getSize(); }
 145     virtual void    shrink() throw() SAL_OVERRIDE
 146                         { MemRingBuffer::shrink(); }
 147
 148 };
 149
 150 // Restore NDEBUG state
 151 #ifdef STREAMHELPER_HXX_HAD_NDEBUG
 152 #define NDEBUG
 153 #else
 154 #undef NDEBUG
 155 #endif
 156
 157 }
 158
 159 #endif // INCLUDED_IO_SOURCE_STM_STREAMHELPER_HXX
 160
 161 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */