    // @(#)root/dcache:$Name:  $:$Id: TDCacheFile.h,v 1.5 2004/04/29 17:05:39 brun Exp $
    // Author: Grzegorz Mazur   20/01/2002
    // Updated: William Tanenbaum 21/11/2003

    /*************************************************************************
     * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
     * All rights reserved.                                                  *
     *                                                                       *
     * For the licensing terms see $ROOTSYS/LICENSE.                         *
     * For the list of contributors see $ROOTSYS/README/CREDITS.             *
     *************************************************************************/

    #ifndef ROOT_TDCacheFile
    #define ROOT_TDCacheFile

    //////////////////////////////////////////////////////////////////////////
    //                                                                      //
    // TDCacheFile                                                          //
    //                                                                      //
    // A TDCacheFile is like a normal TFile except that it reads and writes //
    // its data via a dCache server.                                        //
    //                                                                      //
    //////////////////////////////////////////////////////////////////////////

    #ifndef ROOT_TFile
    #include "TFile.h"
    #endif
    #ifndef ROOT_TSystem
    #include "TSystem.h"
    #endif
    #ifndef ROOT_TString
    #include "TString.h"
    #endif

    #include <sys/stat.h>

    class TDCacheFile : public TFile {

    private:
       Long64_t fOffset;	// file offset
       Bool_t fStatCached;	//! (transient) is file status cached?
       struct stat fStatBuffer;  //! (transient) Cached file status buffer (for performance)

       TDCacheFile() : fOffset(0), fStatCached(kFALSE) { }

       // Interface to basic system I/O routines
       Int_t    SysOpen(const char *pathname, Int_t flags, UInt_t mode);
       Int_t    SysClose(Int_t fd);
       Int_t    SysRead(Int_t fd, void *buf, Int_t len);
       Int_t    SysWrite(Int_t fd, const void *buf, Int_t len);
       Long64_t SysSeek(Int_t fd, Long64_t offset, Int_t whence);
       Int_t    SysStat(Int_t fd, Long_t *id, Long64_t *size, Long_t *flags, Long_t *modtime);
       Int_t    SysSync(Int_t fd);

    public:
       TDCacheFile(const char *path, Option_t *option="",
                   const char *ftitle="", Int_t compress=1);

       ~TDCacheFile();

       Bool_t  ReadBuffer(char *buf, Int_t len);
       Bool_t  WriteBuffer(const char *buf, Int_t len);

       void    ResetErrno() const;

       static Bool_t Stage(const char *path, UInt_t secs,
                           const char *location = 0);
       static Bool_t CheckFile(const char *path, const char *location = 0);

       // Note: This must be kept in sync with values #defined in dcap.h
       enum OnErrorAction {
          kOnErrorRetry   =  1,
          kOnErrorFail    =  0,
          kOnErrorDefault = -1
       };

       static void SetOpenTimeout(UInt_t secs);
       static void SetOnError(OnErrorAction = kOnErrorDefault);

       static void SetReplyHostName(const char *host_name);
       static const char *GetDcapVersion();
       static TString GetDcapPath(const char *path);

       static Bool_t EnableSSL();

       ClassDef(TDCacheFile,1)  //A ROOT file that reads/writes via a dCache server
    };

    class TDCacheSystem : public TSystem {

    private:
       void    *fDirp;   // directory handler

       void    *GetDirPtr() const { return fDirp; }

    public:
       TDCacheSystem();
       virtual ~TDCacheSystem() { }

       Int_t       MakeDirectory(const char *name);
       void       *OpenDirectory(const char *name);
       void        FreeDirectory(void *dirp);
       const char *GetDirEntry(void *dirp);
       Int_t       GetPathInfo(const char *path, Long_t *id, Long64_t *size,
                               Long_t *flags, Long_t *modtime);
       Bool_t      AccessPathName(const char *path, EAccessMode mode);

       ClassDef(TDCacheSystem,0)  // Directory handler for DCache
    };

    #endif