ROOT_528-00b_version: include/TFileCacheWrite.h Source File

00001 // @(#)root/io:$Id: TFileCacheWrite.h 23122 2008-04-10 14:56:30Z rdm $
00002 // Author: Rene Brun   19/05/2006
00003 
00004 /*************************************************************************
00005  * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
00006  * All rights reserved.                                                  *
00007  *                                                                       *
00008  * For the licensing terms see $ROOTSYS/LICENSE.                         *
00009  * For the list of contributors see $ROOTSYS/README/CREDITS.             *
00010  *************************************************************************/
00011 
00012 #ifndef ROOT_TFileCacheWrite
00013 #define ROOT_TFileCacheWrite
00014 
00015 
00016 //////////////////////////////////////////////////////////////////////////
00017 //                                                                      //
00018 // TFileCacheWrite                                                      //
00019 //                                                                      //
00020 // TFile cache when writing                                             //
00021 //                                                                      //
00022 //////////////////////////////////////////////////////////////////////////
00023 
00024 #ifndef ROOT_TObject
00025 #include "TObject.h"
00026 #endif
00027 
00028 class TFile;
00029 
00030 class TFileCacheWrite : public TObject {
00031 
00032 protected:
00033    Long64_t      fSeekStart;      //Seek value of first block in cache
00034    Int_t         fBufferSize;     //Allocated size of fBuffer
00035    Int_t         fNtot;           //Total size of cached blocks
00036    TFile        *fFile;           //Pointer to file
00037    char         *fBuffer;         //[fBufferSize] buffer of contiguous prefetched blocks
00038    Bool_t        fRecursive;      //flag to avoid recursive calls
00039 
00040 private:
00041    TFileCacheWrite(const TFileCacheWrite &);            //cannot be copied
00042    TFileCacheWrite& operator=(const TFileCacheWrite &);
00043 
00044 public:
00045    TFileCacheWrite();
00046    TFileCacheWrite(TFile *file, Int_t buffersize);
00047    virtual ~TFileCacheWrite();
00048    virtual Bool_t      Flush();
00049    virtual Int_t       GetBytesInCache() const { return fNtot; }
00050    virtual void        Print(Option_t *option="") const;
00051    virtual Int_t       ReadBuffer(char *buf, Long64_t pos, Int_t len);
00052    virtual Int_t       WriteBuffer(const char *buf, Long64_t pos, Int_t len);
00053    virtual void        SetFile(TFile *file);
00054 
00055    ClassDef(TFileCacheWrite,1)  //TFile cache when writing
00056 };
00057 
00058 #endif