comphelper/source/streaming/streamsection.cxx

   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 #include <comphelper/streamsection.hxx>
  21 #include <osl/diagnose.h>
  22
  23 namespace comphelper
  24 {
  25
  26
  27 OStreamSection::OStreamSection(const css::uno::Reference< css::io::XDataInputStream >& _rxInput)
  28     :m_xMarkStream(_rxInput, ::com::sun::star::uno::UNO_QUERY)
  29     ,m_xInStream(_rxInput)
  30     ,m_nBlockStart(-1)
  31     ,m_nBlockLen(-1)
  32 {
  33     OSL_ENSURE(m_xInStream.is() && m_xMarkStream.is(), "OStreamSection::OStreamSection : invalid argument !");
  34     if (m_xInStream.is() && m_xMarkStream.is())
  35     {
  36         m_nBlockLen = _rxInput->readLong();
  37         m_nBlockStart = m_xMarkStream->createMark();
  38     }
  39 }
  40
  41
  42 OStreamSection::OStreamSection(const css::uno::Reference< css::io::XDataOutputStream >& _rxOutput, sal_Int32 _nPresumedLength)
  43     :m_xMarkStream(_rxOutput, ::com::sun::star::uno::UNO_QUERY)
  44     ,m_xOutStream(_rxOutput)
  45     ,m_nBlockStart(-1)
  46     ,m_nBlockLen(-1)
  47 {
  48     OSL_ENSURE(m_xOutStream.is() && m_xMarkStream.is(), "OStreamSection::OStreamSection : invalid argument !");
  49     if (m_xOutStream.is() && m_xMarkStream.is())
  50     {
  51         m_nBlockStart = m_xMarkStream->createMark();
  52         // a placeholder where we will write the overall length (within the destructor)
  53         if (_nPresumedLength > 0)
  54             m_nBlockLen = _nPresumedLength + sizeof(m_nBlockLen);
  55             // as the caller did not consider - of course - the placeholder we are going to write
  56         else
  57             m_nBlockLen = 0;
  58         m_xOutStream->writeLong(m_nBlockLen);
  59     }
  60 }
  61
  62
  63 OStreamSection::~OStreamSection()
  64 {
  65     try
  66     {   // don't allow any exceptions to leave this block, this may be called during the stack unwinding of an exception
  67         // handling routing
  68         if (m_xInStream.is() &&  m_xMarkStream.is())
  69         {   // we're working on an input stream
  70             m_xMarkStream->jumpToMark(m_nBlockStart);
  71             m_xInStream->skipBytes(m_nBlockLen);
  72             m_xMarkStream->deleteMark(m_nBlockStart);
  73         }
  74         else if (m_xOutStream.is() && m_xMarkStream.is())
  75         {
  76             sal_Int32 nRealBlockLength = m_xMarkStream->offsetToMark(m_nBlockStart) - sizeof(m_nBlockLen);
  77             if (m_nBlockLen && (m_nBlockLen == nRealBlockLength))
  78                 // nothing to do : the estimation the caller gave us (in the ctor) was correct
  79                 m_xMarkStream->deleteMark(m_nBlockStart);
  80             else
  81             {   // the estimation was wrong (or we didn't get one)
  82                 m_nBlockLen = nRealBlockLength;
  83                 m_xMarkStream->jumpToMark(m_nBlockStart);
  84                 m_xOutStream->writeLong(m_nBlockLen);
  85                 m_xMarkStream->jumpToFurthest();
  86                 m_xMarkStream->deleteMark(m_nBlockStart);
  87             }
  88         }
  89     }
  90     catch(const css::uno::Exception&)
  91     {
  92     }
  93 }
  94
  95
  96 }   // namespace comphelper
  97
  98
  99 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */