comphelper/source/streaming/streamsection.cxx

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  27
  28 // MARKER(update_precomp.py): autogen include statement, do not remove
  29 #include "precompiled_comphelper.hxx"
  30 #include <comphelper/streamsection.hxx>
  31 #include <osl/diagnose.h>
  32
  33 namespace comphelper
  34 {
  35
  36 //-------------------------------------------------------------------------
  37 OStreamSection::OStreamSection(const staruno::Reference< stario::XDataInputStream >& _rxInput)
  38     :m_xMarkStream(_rxInput, ::com::sun::star::uno::UNO_QUERY)
  39     ,m_xInStream(_rxInput)
  40     ,m_nBlockStart(-1)
  41     ,m_nBlockLen(-1)
  42 {
  43     OSL_ENSURE(m_xInStream.is() && m_xMarkStream.is(), "OStreamSection::OStreamSection : invalid argument !");
  44     if (m_xInStream.is() && m_xMarkStream.is())
  45     {
  46         m_nBlockLen = _rxInput->readLong();
  47         m_nBlockStart = m_xMarkStream->createMark();
  48     }
  49 }
  50
  51 //-------------------------------------------------------------------------
  52 OStreamSection::OStreamSection(const staruno::Reference< stario::XDataOutputStream >& _rxOutput, sal_Int32 _nPresumedLength)
  53     :m_xMarkStream(_rxOutput, ::com::sun::star::uno::UNO_QUERY)
  54     ,m_xOutStream(_rxOutput)
  55     ,m_nBlockStart(-1)
  56     ,m_nBlockLen(-1)
  57 {
  58     OSL_ENSURE(m_xOutStream.is() && m_xMarkStream.is(), "OStreamSection::OStreamSection : invalid argument !");
  59     if (m_xOutStream.is() && m_xMarkStream.is())
  60     {
  61         m_nBlockStart = m_xMarkStream->createMark();
  62         // a placeholder where we will write the overall length (within the destructor)
  63         if (_nPresumedLength > 0)
  64             m_nBlockLen = _nPresumedLength + sizeof(m_nBlockLen);
  65             // as the caller did not consider - of course - the placeholder we are going to write
  66         else
  67             m_nBlockLen = 0;
  68         m_xOutStream->writeLong(m_nBlockLen);
  69     }
  70 }
  71
  72 //-------------------------------------------------------------------------
  73 OStreamSection::~OStreamSection()
  74 {
  75     try
  76     {   // don't allow any exceptions to leave this block, this may be called during the stack unwinding of an exception
  77         // handling routing
  78         if (m_xInStream.is() &&  m_xMarkStream.is())
  79         {   // we're working on an input stream
  80             m_xMarkStream->jumpToMark(m_nBlockStart);
  81             m_xInStream->skipBytes(m_nBlockLen);
  82             m_xMarkStream->deleteMark(m_nBlockStart);
  83         }
  84         else if (m_xOutStream.is() && m_xMarkStream.is())
  85         {
  86             sal_Int32 nRealBlockLength = m_xMarkStream->offsetToMark(m_nBlockStart) - sizeof(m_nBlockLen);
  87             if (m_nBlockLen && (m_nBlockLen == nRealBlockLength))
  88                 // nothing to do : the estimation the caller gave us (in the ctor) was correct
  89                 m_xMarkStream->deleteMark(m_nBlockStart);
  90             else
  91             {   // the estimation was wrong (or we didn't get one)
  92                 m_nBlockLen = nRealBlockLength;
  93                 m_xMarkStream->jumpToMark(m_nBlockStart);
  94                 m_xOutStream->writeLong(m_nBlockLen);
  95                 m_xMarkStream->jumpToFurthest();
  96                 m_xMarkStream->deleteMark(m_nBlockStart);
  97             }
  98         }
  99     }
 100     catch(const staruno::Exception&)
 101     {
 102     }
 103 }
 104 // -----------------------------------------------------------------------------
 105 sal_Int32 OStreamSection::available()
 106 {
 107     sal_Int32 nBytes = 0;
 108     try
 109     {   // don't allow any exceptions to leave this block, this may be called during the stack unwinding of an exception
 110         if (m_xInStream.is() &&  m_xMarkStream.is())
 111             nBytes = m_xMarkStream->offsetToMark(m_nBlockStart) - sizeof(m_nBlockLen);
 112     }
 113     catch(const staruno::Exception&)
 114     {
 115     }
 116     return nBytes;
 117 }
 118 // -----------------------------------------------------------------------------
 119
 120 }   // namespace comphelper
 121
 122