sot/source/sdstor/stgcache.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 #ifndef INCLUDED_SOT_SOURCE_SDSTOR_STGCACHE_HXX
  21 #define INCLUDED_SOT_SOURCE_SDSTOR_STGCACHE_HXX
  22
  23 #include <o3tl/safeint.hxx>
  24 #include <osl/endian.h>
  25 #include <rtl/ref.hxx>
  26 #include <tools/stream.hxx>
  27 #include "stgelem.hxx"
  28 #include <salhelper/simplereferenceobject.hxx>
  29
  30 #include <memory>
  31 #include <unordered_map>
  32
  33 class UCBStorageStream;
  34 class StgPage;
  35 class StorageBase;
  36
  37 class StgCache
  38 {
  39     typedef std::unordered_map
  40     <
  41         sal_Int32, rtl::Reference< StgPage >
  42     > IndexToStgPage;
  43
  44     typedef std::vector< rtl::Reference< StgPage > > LRUList;
  45
  46     ErrCode m_nError;                         // error code
  47     sal_Int32 m_nPages;                       // size of data area in pages
  48     sal_uInt16 m_nRef;                        // reference count
  49     IndexToStgPage maDirtyPages;            // hash of all dirty pages
  50     int     m_nReplaceIdx;                    // index into maLRUPages to replace next
  51     LRUList maLRUPages;                     // list of last few non-dirty pages.
  52     short m_nPageSize;                        // page size of the file
  53     UCBStorageStream* m_pStorageStream;       // holds reference to UCB storage stream
  54
  55     void Erase( const rtl::Reference< StgPage >& ); // delete a cache element
  56     rtl::Reference< StgPage > Create( sal_Int32  ); // create a cached page
  57     SvStream* m_pStrm;                        // physical stream
  58     bool  m_bMyStream;                        // true: delete stream in dtor
  59 protected:
  60     bool  m_bFile;                            // true: file stream
  61     sal_Int32 Page2Pos( sal_Int32 ) const;    // page address --> file position
  62 public:
  63     StgCache();
  64     ~StgCache();
  65     void  IncRef()                          { m_nRef++;           }
  66     sal_uInt16 DecRef()                     { return --m_nRef;    }
  67     void  SetPhysPageSize( short );
  68     sal_Int32 GetPhysPages() const          { return m_nPages;    }
  69     short GetPhysPageSize() const           { return m_nPageSize; }
  70     SvStream* GetStrm()                     { return m_pStrm;     }
  71     void  SetStrm( SvStream*, bool );
  72     void  SetStrm( UCBStorageStream* );
  73     bool  Good() const                      { return m_nError == ERRCODE_NONE; }
  74     ErrCode const & GetError() const        { return m_nError;    }
  75     void  MoveError( StorageBase const & );
  76     void  SetError( ErrCode );
  77     void  ResetError();
  78     bool  Open( const OUString& rName, StreamMode );
  79     void  Close();
  80     bool  Read( sal_Int32 nPage, void* pBuf );
  81     bool  Write( sal_Int32 nPage, void const * pBuf );
  82
  83     // two routines for accessing FAT pages
  84     // Assume that the data is a FAT page and get/put FAT data.
  85     void  SetToPage   ( const rtl::Reference< StgPage >& rPage, short nOff, sal_Int32 nVal );
  86     static inline sal_Int32 GetFromPage ( const rtl::Reference< StgPage >& rPage, short nOff );
  87     void  SetDirty    ( const rtl::Reference< StgPage > &rPage );
  88     bool  SetSize( sal_Int32 nPages );
  89     rtl::Reference< StgPage > Find( sal_Int32 );                 // find a cached page
  90     rtl::Reference< StgPage > Get( sal_Int32, bool );            // get a cached page
  91     rtl::Reference< StgPage > Copy( sal_Int32, sal_Int32=STG_FREE ); // copy a page
  92     bool Commit(); // flush all pages
  93     void Clear();                           // clear the cache
  94 };
  95
  96 class StgPage : public salhelper::SimpleReferenceObject
  97 {
  98     const sal_Int32 mnPage;                // page index
  99     std::unique_ptr<sal_uInt8[]>
 100                     mpData;                // nSize bytes
 101     short           mnSize;                // size of this page
 102              StgPage( short nData, sal_Int32 nPage );
 103     virtual ~StgPage() override;
 104 public:
 105              StgPage(const StgPage&) = delete;
 106     StgPage& operator=(const StgPage&) = delete;
 107     static rtl::Reference< StgPage > Create( short nData, sal_Int32 nPage );
 108
 109     sal_Int32 GetPage() const { return mnPage; }
 110     void*     GetData()  { return mpData.get(); }
 111     short     GetSize() const { return mnSize; }
 112
 113 public:
 114     static bool IsPageGreater( const StgPage *pA, const StgPage *pB );
 115 };
 116
 117 inline sal_Int32 StgCache::GetFromPage ( const rtl::Reference< StgPage >& rPage, short nOff )
 118 {
 119     if( nOff < 0 || ( o3tl::make_unsigned(nOff) >= rPage->GetSize() / sizeof( sal_Int32 ) ) )
 120         return -1;
 121     sal_Int32 n = static_cast<sal_Int32*>(rPage->GetData())[ nOff ];
 122 #ifdef OSL_BIGENDIAN
 123     return OSL_SWAPDWORD(n);
 124 #else
 125     return n;
 126 #endif
 127 }
 128
 129 #endif
 130
 131 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */