svx/source/gallery2/codec.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
  21 #include <tools/stream.hxx>
  22 #include <tools/zcodec.hxx>
  23 #include "codec.hxx"
  24 #include <memory>
  25
  26
  27 GalleryCodec::GalleryCodec( SvStream& rIOStm ) :
  28     rStm( rIOStm )
  29 {
  30 }
  31
  32 bool GalleryCodec::IsCoded( SvStream& rStm, sal_uInt32& rVersion )
  33 {
  34     const sal_uInt64   nPos = rStm.Tell();
  35     bool        bRet;
  36     sal_uInt8       cByte1, cByte2, cByte3, cByte4, cByte5, cByte6;
  37
  38     rStm.ReadUChar( cByte1 ).ReadUChar( cByte2 ).ReadUChar( cByte3 ).ReadUChar( cByte4 ).ReadUChar( cByte5 ).ReadUChar( cByte6 );
  39
  40     if ( cByte1 == 'S' && cByte2 == 'V' && cByte3 == 'R' && cByte4 == 'L' && cByte5 == 'E' && ( cByte6 == '1' || cByte6 == '2' ) )
  41     {
  42         rVersion = ( ( cByte6 == '1' ) ? 1 : 2 );
  43         bRet = true;
  44     }
  45     else
  46     {
  47         rVersion = 0;
  48         bRet = false;
  49     }
  50
  51     rStm.Seek( nPos );
  52
  53     return bRet;
  54 }
  55
  56 void GalleryCodec::Write( SvStream& rStmToWrite )
  57 {
  58     sal_uInt32 nPos, nCompSize;
  59
  60     const sal_uInt32 nSize = rStmToWrite.TellEnd();
  61     rStmToWrite.Seek( 0 );
  62
  63     rStm.WriteChar( 'S' ).WriteChar( 'V' ).WriteChar( 'R' ).WriteChar( 'L' ).WriteChar( 'E' ).WriteChar( '2' );
  64     rStm.WriteUInt32( nSize );
  65
  66     nPos = rStm.Tell();
  67     rStm.SeekRel( 4 );
  68
  69     ZCodec aCodec;
  70     aCodec.BeginCompression();
  71     aCodec.Compress( rStmToWrite, rStm );
  72     aCodec.EndCompression();
  73
  74     nCompSize = rStm.Tell() - nPos - 4;
  75     rStm.Seek( nPos );
  76     rStm.WriteUInt32( nCompSize );
  77     rStm.Seek( STREAM_SEEK_TO_END );
  78 }
  79
  80 void GalleryCodec::Read( SvStream& rStmToRead )
  81 {
  82     sal_uInt32 nVersion = 0;
  83
  84     if( !IsCoded( rStm, nVersion ) )
  85         return;
  86
  87     sal_uInt32  nCompressedSize, nUnCompressedSize;
  88
  89     rStm.SeekRel( 6 );
  90     rStm.ReadUInt32( nUnCompressedSize ).ReadUInt32( nCompressedSize );
  91
  92     // decompress
  93     if( 1 == nVersion )
  94     {
  95         std::unique_ptr<sal_uInt8[]> pCompressedBuffer(new sal_uInt8[ nCompressedSize ]);
  96         rStm.ReadBytes(pCompressedBuffer.get(), nCompressedSize);
  97         sal_uInt8*  pInBuf = pCompressedBuffer.get();
  98         std::unique_ptr<sal_uInt8[]> pOutBuf(new sal_uInt8[ nUnCompressedSize ]);
  99         sal_uInt8*  pTmpBuf = pOutBuf.get();
 100         sal_uInt8*  pLast = pOutBuf.get() + nUnCompressedSize - 1;
 101         sal_uIntPtr   nIndex = 0, nCountByte, nRunByte;
 102         bool    bEndDecoding = false;
 103
 104         do
 105         {
 106             nCountByte = *pInBuf++;
 107
 108             if ( !nCountByte )
 109             {
 110                 nRunByte = *pInBuf++;
 111
 112                 if ( nRunByte > 2 )
 113                 {
 114                     // filling absolutely
 115                     memcpy( &pTmpBuf[ nIndex ], pInBuf, nRunByte );
 116                     pInBuf += nRunByte;
 117                     nIndex += nRunByte;
 118
 119                     // note WORD alignment
 120                     if ( nRunByte & 1 )
 121                         pInBuf++;
 122                 }
 123                 else if ( nRunByte == 1 )   // End of the image
 124                     bEndDecoding = true;
 125             }
 126             else
 127             {
 128                 const sal_uInt8 cVal = *pInBuf++;
 129
 130                 memset( &pTmpBuf[ nIndex ], cVal, nCountByte );
 131                 nIndex += nCountByte;
 132             }
 133         }
 134         while ( !bEndDecoding && ( pTmpBuf <= pLast ) );
 135
 136         rStmToRead.WriteBytes(pOutBuf.get(), nUnCompressedSize);
 137     }
 138     else if( 2 == nVersion )
 139     {
 140         ZCodec aCodec;
 141
 142         aCodec.BeginCompression();
 143         aCodec.Decompress( rStm, rStmToRead );
 144         aCodec.EndCompression();
 145     }
 146 }
 147
 148 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */