include/tools/zcodec.hxx

   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 #pragma once
  21
  22 #include <tools/toolsdllapi.h>
  23 #include <tools/long.hxx>
  24 #include <memory>
  25 #include <rtl/string.hxx>
  26
  27 #define ZCODEC_NO_COMPRESSION       0
  28 #define ZCODEC_DEFAULT_COMPRESSION  6
  29
  30 class SvStream;
  31
  32 // The overall client call protocol is one of:
  33 // * BeginCompression, Compress, EndCompression
  34 // * BeginCompression, SetCompressionMetadata, Compress, EndCompression (for gz files)
  35 // * BeginCompression, Decompress, EndCompression
  36 // * BeginCompression, Write*, EndCompression
  37 // * BeginCompression, Read*, EndCompression
  38 // * BeginCompression, ReadAsynchron*, EndCompression
  39 class SAL_WARN_UNUSED TOOLS_DLLPUBLIC ZCodec
  40 {
  41     enum State { STATE_INIT, STATE_DECOMPRESS, STATE_COMPRESS };
  42     State           meState;
  43     bool            mbStatus;
  44     bool            mbFinish;
  45     std::unique_ptr<sal_uInt8[]> mpInBuf;
  46     size_t          mnInBufSize;
  47     size_t          mnInToRead;
  48     SvStream*       mpOStm;
  49     std::unique_ptr<sal_uInt8[]> mpOutBuf;
  50     size_t          mnOutBufSize;
  51     sal_uInt32      mnUncompressedSize;
  52     sal_uInt32      mnInBufCRC32;
  53     sal_uInt32      mnLastModifiedTime;
  54     OString         msFilename;
  55
  56     int             mnCompressLevel;
  57     bool            mbGzLib;
  58     void*           mpsC_Stream;
  59
  60     void            InitCompress();
  61     void            InitDecompress(SvStream & inStream);
  62     void            ImplWriteBack();
  63
  64 public:
  65                     ZCodec( size_t nInBufSize = 32768, size_t nOutBufSize = 32768 );
  66                     ~ZCodec();
  67     /**
  68      * @brief Checks whether a stream is Z compressed
  69      *
  70      * @param rIStm the stream to check
  71      */
  72     static bool IsZCompressed( SvStream& rIStm );
  73
  74     void            BeginCompression( int nCompressLevel = ZCODEC_DEFAULT_COMPRESSION, bool gzLib = false );
  75     tools::Long            EndCompression();
  76
  77     /**
  78      * @brief Set metadata for gzlib compression
  79      *
  80      * @param sFilename the uncompressed file filename
  81      * @param nLastModifiedTime the files last modified time in unix format
  82      */
  83     void            SetCompressionMetadata( const OString& sFilename,
  84                             sal_uInt32 nLastModifiedTime, sal_uInt32 nInBufCRC32 );
  85     void            Compress( SvStream& rIStm, SvStream& rOStm );
  86     tools::Long            Decompress( SvStream& rIStm, SvStream& rOStm );
  87     bool            AttemptDecompression( SvStream& rIStm, SvStream& rOStm );
  88
  89     void            Write( SvStream& rOStm, const sal_uInt8* pData, sal_uInt32 nSize );
  90     tools::Long            Read( SvStream& rIStm, sal_uInt8* pData, sal_uInt32 nSize );
  91 };
  92
  93 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */