TDCacheFile

class TDCacheFile : public TFile

    private:

                       TDCacheFile()
         virtual Int_t SysClose(Int_t fd)
         virtual Int_t SysOpen(const char* pathname, Int_t flags, UInt_t mode)
         virtual Int_t SysRead(Int_t fd, void* buf, Int_t len)
      virtual Long64_t SysSeek(Int_t fd, Long64_t offset, Int_t whence)
         virtual Int_t SysStat(Int_t fd, Long_t* id, Long64_t* size, Long_t* flags, Long_t* modtime)
         virtual Int_t SysSync(Int_t fd)
         virtual Int_t SysWrite(Int_t fd, const void* buf, Int_t len)

    public:

                         TDCacheFile(const char* path, Option_t* option, const char* ftitle, Int_t compress = 1)
                         ~TDCacheFile()
           static Bool_t CheckFile(const char* path, const char* location = "0")
          static TClass* Class()
          static TString GetDcapPath(const char* path)
      static const char* GetDcapVersion() const
         virtual TClass* IsA() const
          virtual Bool_t ReadBuffer(char* buf, Int_t len)
            virtual void ResetErrno() const
             static void SetOnError(TDCacheFile::OnErrorAction = kOnErrorDefault)
             static void SetOpenTimeout(UInt_t secs)
             static void SetReplyHostName(const char* host_name)
            virtual void ShowMembers(TMemberInspector& insp, char* parent)
           static Bool_t Stage(const char* path, UInt_t secs, const char* location = "0")
            virtual void Streamer(TBuffer& b)
                    void StreamerNVirtual(TBuffer& b)
          virtual Bool_t WriteBuffer(const char* buf, Int_t len)

Data Members

    private:

                 Bool_t fStatCached  ! (transient) is file status cached?
      TDCacheFile::stat fStatBuffer  ! (transient) Cached file status buffer (for performance)

    public:

      static const TDCacheFile::OnErrorAction kOnErrorRetry    
      static const TDCacheFile::OnErrorAction kOnErrorFail     
      static const TDCacheFile::OnErrorAction kOnErrorDefault  

Class Description

                                                                      
 TDCacheFile                                                          
                                                                      
 A TDCacheFile is like a normal TFile except that it may read and     
 write its data via a dCache server (for more on the dCache daemon    
 see http://www-dcache.desy.de/. Given a path which doesn't belong    
 to the dCache managed filesystem, it falls back to the ordinary      
 TFile behaviour.                                                     
                                                                      

 Create a dCache file object. A dCache file is the same as a TFile
 except that it is being accessed via a dCache server. The url
 argument must be of the form: dcache://path/file.root or
 dcap://path/file.root. If the file specified in the URL does not
 exist, is not accessable or can not be created the kZombie bit will
 be set in the TDCacheFile object. Use IsZombie() to see if the file
 is accessable. For a description of the option and other arguments
 see the TFile ctor. The preferred interface to this constructor is
 via TFile::Open().

 Close and cleanup dCache file.

 Read specified byte range from remote file via dCache daemon.
 Returns kTRUE in case of error.

 Write specified byte range to remote file via dCache daemon.
 Returns kTRUE in case of error.

 Stage() returns kTRUE on success and kFALSE on failure.

 CheckFile() returns kTRUE on success and kFALSE on failure.  In
 case the file exists but is not cached, CheckFile() returns
 kFALSE and errno is set to EAGAIN.

 Set file open timeout.

 Set on error handler.

 Set reply host name.

 Return dCache version string.

 Interface to system open. All arguments like in POSIX open.

 Interface to system close. All arguments like in POSIX close.

 Interface to system read. All arguments like in POSIX read.

 Interface to system write. All arguments like in POSIX write.

 Interface to system seek. All arguments like in POSIX lseek.

 Interface to system sync. All arguments like in POSIX fsync.
 dCache always keep it's files sync'ed, so there's no need to
 sync() them manually.

 Get info about a file: id, size, flags, modification time.
 Id      is (statbuf.st_dev << 24) + statbuf.st_ino
 Size    is the file size
 Flags   is file type: 0 is regular file, bit 0 set executable,
                       bit 1 set directory, bit 2 set special file
                       (socket, fifo, pipe, etc.)
 Modtime is modification time.
 The function returns 0 in case of success and 1 if the file could
 not be stat'ed.

 Method resetting the dc_errno and errno.

 Transform the input path into a path usuable by the dcap C library,
 i.e either dcap://nodename.org/where/filename.root or
 //pnfs/where/filename.root

Inline Functions

        TDCacheFile TDCacheFile(const char* path, Option_t* option, const char* ftitle, Int_t compress = 1)
            TClass* Class()
            TClass* IsA() const
               void ShowMembers(TMemberInspector& insp, char* parent)
               void Streamer(TBuffer& b)
               void StreamerNVirtual(TBuffer& b)