comphelper/source/streaming/seqstream.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/seqstream.hxx>
  21
  22 #include <memory.h> // for memcpy
  23
  24 namespace comphelper
  25 {
  26 using namespace ::com::sun::star::lang;
  27 using namespace ::com::sun::star::io;
  28 using namespace ::com::sun::star::uno;
  29 using namespace ::osl;
  30
  31 //---------------------------------------------------------------------------------------------
  32 // class SequenceInputStream
  33 //---------------------------------------------------------------------------------------------
  34
  35 //------------------------------------------------------------------
  36 SequenceInputStream::SequenceInputStream(const ByteSequence& rData)
  37 :   m_aData(rData)
  38 ,   m_nPos(0)
  39 {
  40 }
  41
  42 // checks if closed, returns available size, not mutex-protected
  43 //------------------------------------------------------------------
  44 inline sal_Int32 SequenceInputStream::avail()
  45 {
  46     if (m_nPos == -1)
  47         throw NotConnectedException(OUString(), *this);
  48
  49     return m_aData.getLength() - m_nPos;
  50 }
  51
  52 // com::sun::star::io::XInputStream
  53 //------------------------------------------------------------------
  54 sal_Int32 SAL_CALL SequenceInputStream::readBytes( Sequence<sal_Int8>& aData, sal_Int32 nBytesToRead )
  55     throw(NotConnectedException, BufferSizeExceededException,
  56           IOException, RuntimeException)
  57 {
  58     ::osl::MutexGuard aGuard( m_aMutex );
  59
  60     sal_Int32 nAvail = avail();
  61
  62     if (nBytesToRead < 0)
  63         throw BufferSizeExceededException(OUString(),*this);
  64
  65     if (nAvail < nBytesToRead)
  66         nBytesToRead = nAvail;
  67
  68     aData.realloc(nBytesToRead);
  69     memcpy(aData.getArray(), m_aData.getConstArray() + m_nPos, nBytesToRead);
  70     m_nPos += nBytesToRead;
  71
  72     return nBytesToRead;
  73 }
  74
  75 //------------------------------------------------------------------
  76 sal_Int32 SAL_CALL SequenceInputStream::readSomeBytes( Sequence<sal_Int8>& aData, sal_Int32 nMaxBytesToRead )
  77     throw(NotConnectedException, BufferSizeExceededException,
  78           IOException, RuntimeException)
  79 {
  80     // all data is available at once
  81     return readBytes(aData, nMaxBytesToRead);
  82 }
  83
  84 //------------------------------------------------------------------
  85 void SAL_CALL SequenceInputStream::skipBytes( sal_Int32 nBytesToSkip )
  86     throw(NotConnectedException, BufferSizeExceededException,
  87           IOException, RuntimeException)
  88 {
  89     ::osl::MutexGuard aGuard( m_aMutex );
  90
  91     sal_Int32 nAvail = avail();
  92
  93     if (nBytesToSkip < 0)
  94         throw BufferSizeExceededException(OUString(),*this);
  95
  96     if (nAvail < nBytesToSkip)
  97         nBytesToSkip = nAvail;
  98
  99     m_nPos += nBytesToSkip;
 100 }
 101
 102 //------------------------------------------------------------------
 103 sal_Int32 SAL_CALL SequenceInputStream::available(  )
 104     throw(NotConnectedException, IOException, RuntimeException)
 105 {
 106     ::osl::MutexGuard aGuard( m_aMutex );
 107
 108     return avail();
 109 }
 110
 111 //------------------------------------------------------------------
 112 void SAL_CALL SequenceInputStream::closeInput(  )
 113     throw(NotConnectedException, IOException, RuntimeException)
 114 {
 115     if (m_nPos == -1)
 116         throw NotConnectedException(OUString(), *this);
 117
 118     m_nPos = -1;
 119 }
 120
 121 void SAL_CALL SequenceInputStream::seek( sal_Int64 location ) throw (IllegalArgumentException, IOException, RuntimeException)
 122 {
 123     if ( location > m_aData.getLength() || location < 0 || location > SAL_MAX_INT32 )
 124         throw IllegalArgumentException();
 125     m_nPos = (sal_Int32) location;
 126 }
 127
 128 sal_Int64 SAL_CALL SequenceInputStream::getPosition() throw (IOException, RuntimeException)
 129 {
 130     return m_nPos;
 131 }
 132
 133 sal_Int64 SAL_CALL SequenceInputStream::getLength(  ) throw (IOException, RuntimeException)
 134 {
 135     return m_aData.getLength();
 136 }
 137
 138 //--------------------------------------------------------------------------
 139 OSequenceOutputStream::OSequenceOutputStream(Sequence< sal_Int8 >& _rSeq, double _nResizeFactor, sal_Int32 _nMinimumResize, sal_Int32 _nMaximumResize)
 140     :m_rSequence(_rSeq)
 141     ,m_nResizeFactor(_nResizeFactor)
 142     ,m_nMinimumResize(_nMinimumResize)
 143     ,m_nMaximumResize(_nMaximumResize)
 144     ,m_nSize(0) // starting at position 0
 145     ,m_bConnected(sal_True)
 146 {
 147     OSL_ENSURE(m_nResizeFactor > 1, "OSequenceOutputStream::OSequenceOutputStream : invalid resize factor !");
 148     OSL_ENSURE((m_nMaximumResize < 0) || (m_nMaximumResize > m_nMinimumResize),
 149         "OSequenceOutputStream::OSequenceOutputStream : these limits don't make any sense !");
 150
 151     if (m_nResizeFactor <= 1)
 152         m_nResizeFactor = 1.3;
 153     if ((m_nMaximumResize >= 0) && (m_nMaximumResize <= m_nMinimumResize))
 154         m_nMaximumResize = m_nMinimumResize * 2;
 155         // this heuristic is as good as any other ... supply better parameters if you don't like it :)
 156 }
 157
 158 //--------------------------------------------------------------------------
 159 void SAL_CALL OSequenceOutputStream::writeBytes( const Sequence< sal_Int8 >& _rData ) throw(NotConnectedException, BufferSizeExceededException, IOException, RuntimeException)
 160 {
 161     MutexGuard aGuard(m_aMutex);
 162     if (!m_bConnected)
 163         throw NotConnectedException();
 164
 165     // ensure the sequence has enoungh space left
 166     if (m_nSize + _rData.getLength() > m_rSequence.getLength())
 167     {
 168         sal_Int32 nCurrentLength = m_rSequence.getLength();
 169         sal_Int32 nNewLength = static_cast< sal_Int32 >(
 170             nCurrentLength * m_nResizeFactor);
 171
 172         if (m_nMinimumResize > nNewLength - nCurrentLength)
 173             // we have a minimum so it's not too inefficient for small sequences and small write requests
 174             nNewLength = nCurrentLength + m_nMinimumResize;
 175
 176         if ((m_nMaximumResize > 0) && (nNewLength - nCurrentLength > m_nMaximumResize))
 177             // such a large step is not allowed
 178             nNewLength = nCurrentLength + m_nMaximumResize;
 179
 180         if (nNewLength < m_nSize + _rData.getLength())
 181         {   // it's not enough .... the data would not fit
 182
 183             // let's take the double amount of the length of the data to be written, as the next write
 184             // request could be as large as this one
 185             sal_Int32 nNewGrowth = _rData.getLength() * 2;
 186             if ((m_nMaximumResize > 0) && (nNewGrowth > m_nMaximumResize))
 187             {   // we came to the limit, again ...
 188                 nNewGrowth = m_nMaximumResize;
 189                 if (nNewGrowth + nCurrentLength < m_nSize + _rData.getLength())
 190                     // but it would not fit if we respect the limit
 191                     nNewGrowth = m_nSize + _rData.getLength() - nCurrentLength;
 192             }
 193             nNewLength = nCurrentLength + nNewGrowth;
 194         }
 195
 196         // round it off to the next multiple of 4 ...
 197         nNewLength = (nNewLength + 3) / 4 * 4;
 198
 199         m_rSequence.realloc(nNewLength);
 200     }
 201
 202     OSL_ENSURE(m_rSequence.getLength() >= m_nSize + _rData.getLength(),
 203         "ooops ... the realloc algorithm seems to be wrong :( !");
 204
 205     memcpy(m_rSequence.getArray() + m_nSize, _rData.getConstArray(), _rData.getLength());
 206     m_nSize += _rData.getLength();
 207 }
 208
 209 //--------------------------------------------------------------------------
 210 void SAL_CALL OSequenceOutputStream::flush(  ) throw(NotConnectedException, BufferSizeExceededException, IOException, RuntimeException)
 211 {
 212     MutexGuard aGuard(m_aMutex);
 213     if (!m_bConnected)
 214         throw NotConnectedException();
 215
 216     // cut the sequence to the real size
 217     m_rSequence.realloc(m_nSize);
 218 }
 219
 220 //--------------------------------------------------------------------------
 221 void SAL_CALL OSequenceOutputStream::closeOutput(  ) throw(NotConnectedException, BufferSizeExceededException, IOException, RuntimeException)
 222 {
 223     MutexGuard aGuard(m_aMutex);
 224     if (!m_bConnected)
 225         throw NotConnectedException();
 226
 227     // cut the sequence to the real size
 228     m_rSequence.realloc(m_nSize);
 229     // and don't allow any further accesses
 230     m_bConnected = sal_False;
 231 }
 232
 233 } // namespace comphelper
 234
 235 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */