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 _STGCACHE_HXX
  21 #define _STGCACHE_HXX
  22
  23 #include <osl/endian.h>
  24 #include <rtl/ref.hxx>
  25 #include <tools/solar.h>
  26 #include <tools/stream.hxx>
  27 #include <stgelem.hxx>
  28 #include <boost/noncopyable.hpp>
  29 #include <boost/unordered_map.hpp>
  30
  31 class UCBStorageStream;
  32 class StgPage;
  33 class StgDirEntry;
  34 class StorageBase;
  35
  36 class StgCache
  37 {
  38     typedef boost::unordered_map
  39     <
  40         sal_Int32, rtl::Reference< StgPage >,
  41         boost::hash< sal_Int32 >, std::equal_to< sal_Int32 >
  42     > IndexToStgPage;
  43
  44     typedef std::vector< rtl::Reference< StgPage > > LRUList;
  45
  46     sal_uLong nError;                       // error code
  47     sal_Int32 nPages;                       // size of data area in pages
  48     sal_uInt16 nRef;                        // reference count
  49     IndexToStgPage maDirtyPages;            // hash of all dirty pages
  50     int     nReplaceIdx;                    // index into maLRUPages to replace next
  51     LRUList maLRUPages;                     // list of last few non-dirty pages.
  52     short nPageSize;                        // page size of the file
  53     UCBStorageStream* 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 protected:
  58     SvStream* pStrm;                        // physical stream
  59     bool  bMyStream;                        // true: delete stream in dtor
  60     bool  bFile;                            // true: file stream
  61     sal_Int32 Page2Pos( sal_Int32 );        // page address --> file position
  62 public:
  63     StgCache();
  64     ~StgCache();
  65     void  IncRef()                          { nRef++;           }
  66     sal_uInt16 DecRef()                     { return --nRef;    }
  67     void  SetPhysPageSize( short );
  68     sal_Int32 GetPhysPages()                { return nPages;    }
  69     short GetPhysPageSize()                 { return nPageSize; }
  70     SvStream* GetStrm()                     { return pStrm;     }
  71     void  SetStrm( SvStream*, bool );
  72     void  SetStrm( UCBStorageStream* );
  73     bool  IsWritable()                      { return ( pStrm && pStrm->IsWritable() ); }
  74     bool  Good()                            { return nError == SVSTREAM_OK; }
  75     bool  Bad()                             { return nError != SVSTREAM_OK; }
  76     sal_uLong GetError()                    { return nError;    }
  77     void  MoveError( StorageBase& );
  78     void  SetError( sal_uLong );
  79     void  ResetError();
  80     bool  Open( const OUString& rName, StreamMode );
  81     void  Close();
  82     bool  Read( sal_Int32 nPage, void* pBuf, sal_Int32 nPages );
  83     bool  Write( sal_Int32 nPage, void* pBuf, sal_Int32 nPages );
  84
  85     // two routines for accessing FAT pages
  86     // Assume that the data is a FAT page and get/put FAT data.
  87     void  SetToPage   ( const rtl::Reference< StgPage > xPage, short nOff, sal_Int32 nVal );
  88     inline sal_Int32 GetFromPage ( const rtl::Reference< StgPage > xPage, short nOff );
  89     void  SetDirty    ( const rtl::Reference< StgPage > &xPage );
  90     bool  SetSize( sal_Int32 nPages );
  91     rtl::Reference< StgPage > Find( sal_Int32 );                 // find a cached page
  92     rtl::Reference< StgPage > Get( sal_Int32, bool );            // get a cached page
  93     rtl::Reference< StgPage > Copy( sal_Int32, sal_Int32=STG_FREE ); // copy a page
  94     bool Commit(); // flush all pages
  95     void Clear();                           // clear the cache
  96 };
  97
  98 class StgPage : public rtl::IReference, private boost::noncopyable {
  99     sal_uInt32      mnRefCount;
 100     const sal_Int32 mnPage;                // page index
 101     sal_uInt8*      mpData;                // nSize bytes
 102     short           mnSize;                // size of this page
 103              StgPage( short nData, sal_Int32 nPage );
 104     virtual ~StgPage();
 105 public:
 106     static rtl::Reference< StgPage > Create( short nData, sal_Int32 nPage );
 107
 108     sal_Int32 GetPage()  { return mnPage; }
 109     void*     GetData()  { return mpData; }
 110     short     GetSize()  { return mnSize; }
 111
 112 public:
 113     virtual oslInterlockedCount SAL_CALL acquire()
 114     {
 115         return ++mnRefCount;
 116     }
 117     virtual oslInterlockedCount SAL_CALL release()
 118     {
 119         if ( --mnRefCount == 0)
 120         {
 121             delete this;
 122             return 0;
 123         }
 124         return mnRefCount;
 125     }
 126     static bool IsPageGreater( const StgPage *pA, const StgPage *pB );
 127 };
 128
 129 inline sal_Int32 StgCache::GetFromPage ( const rtl::Reference< StgPage > xPage, short nOff )
 130 {
 131     if( ( nOff >= (short) ( xPage->GetSize() / sizeof( sal_Int32 ) ) ) || nOff < 0 )
 132         return -1;
 133     sal_Int32 n = ((sal_Int32*) xPage->GetData() )[ nOff ];
 134 #ifdef OSL_BIGENDIAN
 135     return OSL_SWAPDWORD(n);
 136 #else
 137     return n;
 138 #endif
 139 }
 140
 141 #endif
 142
 143 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */