comphelper/source/streaming/streamsection.cxx

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  30
  31 // MARKER(update_precomp.py): autogen include statement, do not remove
  32 #include "precompiled_comphelper.hxx"
  33 #include <comphelper/streamsection.hxx>
  34 #include <osl/diagnose.h>
  35
  36 namespace comphelper
  37 {
  38
  39 //-------------------------------------------------------------------------
  40 OStreamSection::OStreamSection(const staruno::Reference< stario::XDataInputStream >& _rxInput)
  41     :m_xMarkStream(_rxInput, ::com::sun::star::uno::UNO_QUERY)
  42     ,m_xInStream(_rxInput)
  43     ,m_nBlockStart(-1)
  44     ,m_nBlockLen(-1)
  45 {
  46     OSL_ENSURE(m_xInStream.is() && m_xMarkStream.is(), "OStreamSection::OStreamSection : invalid argument !");
  47     if (m_xInStream.is() && m_xMarkStream.is())
  48     {
  49         m_nBlockLen = _rxInput->readLong();
  50         m_nBlockStart = m_xMarkStream->createMark();
  51     }
  52 }
  53
  54 //-------------------------------------------------------------------------
  55 OStreamSection::OStreamSection(const staruno::Reference< stario::XDataOutputStream >& _rxOutput, sal_Int32 _nPresumedLength)
  56     :m_xMarkStream(_rxOutput, ::com::sun::star::uno::UNO_QUERY)
  57     ,m_xOutStream(_rxOutput)
  58     ,m_nBlockStart(-1)
  59     ,m_nBlockLen(-1)
  60 {
  61     OSL_ENSURE(m_xOutStream.is() && m_xMarkStream.is(), "OStreamSection::OStreamSection : invalid argument !");
  62     if (m_xOutStream.is() && m_xMarkStream.is())
  63     {
  64         m_nBlockStart = m_xMarkStream->createMark();
  65         // a placeholder where we will write the overall length (within the destructor)
  66         if (_nPresumedLength > 0)
  67             m_nBlockLen = _nPresumedLength + sizeof(m_nBlockLen);
  68             // as the caller did not consider - of course - the placeholder we are going to write
  69         else
  70             m_nBlockLen = 0;
  71         m_xOutStream->writeLong(m_nBlockLen);
  72     }
  73 }
  74
  75 //-------------------------------------------------------------------------
  76 OStreamSection::~OStreamSection()
  77 {
  78     try
  79     {   // don't allow any exceptions to leave this block, this may be called during the stack unwinding of an exception
  80         // handling routing
  81         if (m_xInStream.is() &&  m_xMarkStream.is())
  82         {       // we're working on an input stream
  83             m_xMarkStream->jumpToMark(m_nBlockStart);
  84             m_xInStream->skipBytes(m_nBlockLen);
  85             m_xMarkStream->deleteMark(m_nBlockStart);
  86         }
  87         else if (m_xOutStream.is() && m_xMarkStream.is())
  88         {
  89             sal_Int32 nRealBlockLength = m_xMarkStream->offsetToMark(m_nBlockStart) - sizeof(m_nBlockLen);
  90             if (m_nBlockLen && (m_nBlockLen == nRealBlockLength))
  91                 // nothing to do : the estimation the caller gave us (in the ctor) was correct
  92                 m_xMarkStream->deleteMark(m_nBlockStart);
  93             else
  94             {   // the estimation was wrong (or we didn't get one)
  95                 m_nBlockLen = nRealBlockLength;
  96                 m_xMarkStream->jumpToMark(m_nBlockStart);
  97                 m_xOutStream->writeLong(m_nBlockLen);
  98                 m_xMarkStream->jumpToFurthest();
  99                 m_xMarkStream->deleteMark(m_nBlockStart);
 100             }
 101         }
 102     }
 103     catch(const staruno::Exception&)
 104     {
 105     }
 106 }
 107 // -----------------------------------------------------------------------------
 108 sal_Int32 OStreamSection::available()
 109 {
 110     sal_Int32 nBytes = 0;
 111     try
 112     {   // don't allow any exceptions to leave this block, this may be called during the stack unwinding of an exception
 113         if (m_xInStream.is() &&  m_xMarkStream.is())
 114             nBytes = m_xMarkStream->offsetToMark(m_nBlockStart) - sizeof(m_nBlockLen);
 115     }
 116     catch(const staruno::Exception&)
 117     {
 118     }
 119     return nBytes;
 120 }
 121 // -----------------------------------------------------------------------------
 122
 123 }       // namespace comphelper
 124
 125