XrdSfsInterface.hh

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#ifndef __SFS_INTERFACE_H__
#define __SFS_INTERFACE_H__
/******************************************************************************/
/*                                                                            */
/*                    X r d S f s I n t e r f a c e . h h                     */
/*                                                                            */
/* (c) 2018 by the Board of Trustees of the Leland Stanford, Jr., University  */
/*   Produced by Andrew Hanushevsky for Stanford University under contract    */
/*              DE-AC02-76-SFO0515 with the Department of Energy              */
/*                                                                            */
/* This file is part of the XRootD software suite.                            */
/*                                                                            */
/* XRootD is free software: you can redistribute it and/or modify it under    */
/* the terms of the GNU Lesser General Public License as published by the     */
/* Free Software Foundation, either version 3 of the License, or (at your     */
/* option) any later version.                                                 */
/*                                                                            */
/* XRootD is distributed in the hope that it will be useful, but WITHOUT      */
/* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or      */
/* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public       */
/* License for more details.                                                  */
/*                                                                            */
/* You should have received a copy of the GNU Lesser General Public License   */
/* along with XRootD in a file called COPYING.LESSER (LGPL license) and file  */
/* COPYING (GPL license).  If not, see <http://www.gnu.org/licenses/>.        */
/*                                                                            */
/* The copyright holder's institutional names and contributor's names may not */
/* be used to endorse or promote products derived from this software without  */
/* specific prior written permission of the institution or contributor.       */
/******************************************************************************/
 
#include <cstring>      // For strlcpy()
#include <cerrno>
#include <cstdint>
#include <sys/types.h>
#include <sys/stat.h>
 
#include "XrdOuc/XrdOucErrInfo.hh"
#include "XrdOuc/XrdOucIOVec.hh"
#include "XrdOuc/XrdOucSFVec.hh"
 
#include "XrdSfs/XrdSfsGPFile.hh"
 
#include "XrdSys/XrdSysPageSize.hh"
 
/******************************************************************************/
/*                            O p e n   M o d e s                             */
/******************************************************************************/
 
#define SFS_O_RDONLY           0         // open read/only
#define SFS_O_WRONLY           1         // open write/only
#define SFS_O_RDWR             2         // open read/write
#define SFS_O_CREAT   0x00000100         // used for file creation
#define SFS_O_TRUNC   0x00000200         // used for file truncation
#define SFS_O_MULTIW  0x00000400         // used for multi-write locations
#define SFS_O_NOTPC   0x00000800         // used to suppress TPC opens
#define SFS_O_DIRLIST 0x00010000         // used for locate only
#define SFS_O_POSC    0x00100000         // persist on successful close
#define SFS_O_FORCE   0x00200000         // used for locate only
#define SFS_O_HNAME   0x00400000         // used for locate only
#define SFS_O_LOCAL   0x00800000         // used for locate only (local cmd)
#define SFS_O_NOWAIT  0x01000000         // do not impose operational delays
#define SFS_O_RAWIO   0x02000000         // allow client-side decompression
#define SFS_O_RESET   0x04000000         // Reset any cached information
#define SFS_O_REPLICA 0x08000000         // Open for replication
 
// The following flag may be set in the access mode arg for open() & mkdir()
// Note that on some systems mode_t is 16-bits so we use a careful value!
//
#define SFS_O_MKPTH   0x00004000         // Make directory path if missing
 
// The following options are here to provide a uniform clustering interface.
// They may be passed through open/locate/stat, as applicable.
//
#define SFS_O_LOCATE  0x10000000         // This request generated by locate()
#define SFS_O_STAT    0x20000000         // This request generated by stat()
#define SFS_O_META    0x40000000         // This request generated by metaop
 
/******************************************************************************/
/*                               D e f i n e s                                */
/******************************************************************************/
 
// Common fctl  command values (0 to 255)
//
#define SFS_FCTL_GETFD    1 // Return file descriptor if possible
#define SFS_FCTL_STATV    2 // Return visa information
#define SFS_FCTL_SPEC1    3 // Return implementation defined information
 
#define SFS_SFIO_FDVAL 0x80000000 // Use SendData() method GETFD response value
 
// Common fsctl command values (0 to 255)
//
#define SFS_FSCTL_CMD   255
 
#define SFS_FSCTL_LOCATE  1 // Locate a file
#define SFS_FSCTL_STATFS  2 // Return FS data
#define SFS_FSCTL_STATLS  3 // Return LS data
#define SFS_FSCTL_STATXA  4 // Return XA data
#define SFS_FSCTL_STATCC  5 // Return Cluster Config status
#define SFS_FSCTL_PLUGIN  8 // Return Implementation Dependent Data
#define SFS_FSCTL_PLUGIO 16 // Return Implementation Dependent Data
#define SFS_FSCTL_PLUGXC 32 // Perform cache oriented operation
 
// Return values for integer & XrdSfsXferSize returning XrdSfs methods
//
#define SFS_STALL         1 // Return value -> Seconds to stall client
#define SFS_OK            0 // ErrInfo code -> All is well
#define SFS_ERROR        -1 // ErrInfo code -> Error occurred
#define SFS_REDIRECT   -256 // ErrInfo code -> Port number to redirect to
#define SFS_STARTED    -512 // ErrInfo code -> Estimated seconds to completion
#define SFS_DATA      -1024 // ErrInfo code -> Length of data
#define SFS_DATAVEC   -2048 // ErrInfo code -> Num iovec elements in msgbuff
 
// The following macros are used for dealing with special local paths
//
#define SFS_LCLPRFX    "/=/"
#define SFS_LCLPLEN    3
#define SFS_LCLPATH(x) !strncmp(x, SFS_LCLPRFX, SFS_LCLPLEN)
#define SFS_LCLPRFY    "/="
#define SFS_LCLROOT(x) !strncmp(x, SFS_LCLPRFX, SFS_LCLPLEN-1) \
                       && (*(x+SFS_LCLPLEN-1) == '/' || *(x+SFS_LCLPLEN-1) == 0)
 
/******************************************************************************/
/*                 S t r u c t u r e s   &   T y p e d e f s                  */
/******************************************************************************/
 
typedef long long     XrdSfsFileOffset;
typedef int           XrdSfsFileOpenMode;
typedef int           XrdSfsMode;
typedef int           XrdSfsXferSize;
 
enum XrdSfsFileExistence 
{
     XrdSfsFileExistNo,
     XrdSfsFileExistIsFile,
     XrdSfsFileExistIsDirectory,
     XrdSfsFileExistIsOffline,
     XrdSfsFileExistIsOther
};
//------------------------------------------------
 
#define Prep_PRTY0 0
#define Prep_PRTY1 1
#define Prep_PRTY2 2
#define Prep_PRTY3 3
#define Prep_PMASK 3
#define Prep_SENDAOK 4
#define Prep_SENDERR 8
#define Prep_SENDACK 12
#define Prep_WMODE   16
#define Prep_STAGE   32
#define Prep_COLOC   64
#define Prep_FRESH  128
#define Prep_CANCEL 256
#define Prep_QUERY  512
#define Prep_EVICT 1024
 
class XrdOucTList;
 
struct XrdSfsFSctl 
{
 const char            *Arg1;      
       int              Arg1Len;   
       int              Arg2Len;   
 union{
 const char            *Arg2;      
 const char           **ArgP;      
      };
};
 
struct XrdSfsPrep  
{
       char            *reqid;     
       char            *notify;    
       int              opts;      
       XrdOucTList     *paths;     
       XrdOucTList     *oinfo;     
};
 
/******************************************************************************/
/*                  F o r w a r d   D e c l a r a t i o n s                   */
/******************************************************************************/
 
class  XrdOucEnv;
class  XrdSecEntity;
struct XrdSfsFACtl;
 
/******************************************************************************/
/*                 O b j e c t   W r a p p i n g   G u i d e                  */
/******************************************************************************/
 
/* The XrdSfsDirectory and XrdSfsFile objects can be wrapped. Wraping can be
   used to add functionality. The process is common and pretty muche rote.
   There is only one caveat: all wrappers must use the same XrdOucErrInfo
   object. This is because the ErrInfo object contains client parameters that
   are used to control how things are done to be backward compatible. Newer
   client can then use more efficient internal processing. The SFS provides
   two ways to make sure the same ErrInfo object is used by all objects in
   the wrapped chain. Forward propagation (the one typically used) and
   backward propagation (used in certain unusual cases). In forward mode,
   the ErrInfo object of the last object in the chain is propagated to the
   front of the chain. In backward mode the reverse happens. Let's assume
   the following scenarion. Object-A wraps object-B (the object here can be
   directory or file object). In forward mode weneed to create objects in
   reverse order (bottom to top) which is typically what you would do anyway
   as you need to capture the pinter to the object your wrapping. So, using
   newFile() as an example where sfsP points to the Interface being wrapped:
 
   XrdSfsFile *newFile(const char *user, int MonID)
   {
      XrdSfsFile *wrapped_file = sfsP->newFile(user, MonID);
      if (!wrapped_file) return 0;
      return new mySfsFile(wrapped_file,...);
   }
   class mySfsFile : public XrdSfsFile
   {public:
      mySfsFile(XrdSfsFile *wrapped_file,...) : XrdSfsFile(*wrapped_file)
               {....}
    ....
   };
 
   Notice we are allocating the wrapped file ahead of the wrapper so that
   the wrapper can use the ErrInfo object of the wrapped file.
 
   In backward mode we want to use the ErrInfo object of the front-most
   wrapper for all wrappers after it. This mechanism is far more complicated
   due to error handling requirements. However, it's useful when a wrapped
   object is not necessarily instantiated to accomplish the needs of the
   wrapper. An example of this is the newFile and newDir implementations for
   XrdSsi where wrapped object creation is subject to the resource name.
*/
 
/******************************************************************************/
/*                       X r d S f s D i r e c t o r y                        */
/******************************************************************************/
 
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
  
class XrdSfsDirectory
{
public:
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
        XrdOucErrInfo &error;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int         open(const char              *path,
                         const XrdSecEntity      *client = 0,
                         const char              *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual const char *nextEntry() = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int         close() = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual const char *FName() = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int         autoStat(struct stat *buf);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
                    XrdSfsDirectory(const char *user=0, int MonID=0)
                                   : error(*(new XrdOucErrInfo(user, MonID)))
                                   {lclEI = &error;}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
                    XrdSfsDirectory(XrdSfsDirectory &wrapD)
                                   : error(wrapD.error), lclEI(0) {}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
                    XrdSfsDirectory(XrdOucErrInfo &eInfo)
                                   : error(eInfo), lclEI(0) {}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual            ~XrdSfsDirectory() {if (lclEI) delete lclEI;}
 
private:
XrdOucErrInfo* lclEI;
 
}; // class XrdSfsDirectory
 
/******************************************************************************/
/*                            X r d S f s F i l e                             */
/******************************************************************************/
 
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
 
class XrdSfsAio;
class XrdSfsDio;
class XrdSfsXio;
  
class XrdSfsFile
{
public:
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
        XrdOucErrInfo  &error;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            open(const char                *fileName,
                                  XrdSfsFileOpenMode   openMode,
                                  mode_t               createMode,
                            const XrdSecEntity        *client = 0,
                            const char                *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
enum cpAct {cpCreate=0,   
            cpDelete,     
            cpRestore,    
            cpQuery,      
            cpTrunc,      
            cpWrite       
           };
 
virtual int            checkpoint(cpAct act, struct iov *range=0, int n=0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            close() = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            fctl(const int               cmd,
                            const char             *args,
                                  XrdOucErrInfo    &eInfo) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            fctl(const int               cmd,
                                  int               alen,
                                  const char       *args,
                            const XrdSecEntity     *client = 0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual const char    *FName() = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            getMmap(void **Addr, off_t &Size) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
static const uint64_t
Verify       = 0x8000000000000000ULL; 
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsXferSize pgRead(XrdSfsFileOffset   offset,
                              char              *buffer,
                              XrdSfsXferSize     rdlen,
                              uint32_t          *csvec,
                              uint64_t           opts=0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            pgRead(XrdSfsAio *aioparm, uint64_t opts=0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsXferSize pgWrite(XrdSfsFileOffset   offset,
                               char              *buffer,
                               XrdSfsXferSize     wrlen,
                               uint32_t          *csvec,
                               uint64_t           opts=0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            pgWrite(XrdSfsAio *aioparm, uint64_t opts=0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsXferSize read(XrdSfsFileOffset   offset,
                            XrdSfsXferSize     size) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsXferSize read(XrdSfsFileOffset   offset,
                            char              *buffer,
                            XrdSfsXferSize     size) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            read(XrdSfsAio *aioparm) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsXferSize readv(XrdOucIOVec      *readV,
                             int               rdvCnt);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            SendData(XrdSfsDio         *sfDio,
                                XrdSfsFileOffset   offset,
                                XrdSfsXferSize     size);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsXferSize write(XrdSfsFileOffset  offset,
                             const char       *buffer,
                             XrdSfsXferSize    size) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            write(XrdSfsAio *aioparm) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsXferSize writev(XrdOucIOVec      *writeV,
                              int               wdvCnt);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            stat(struct stat *buf) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            sync() = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            sync(XrdSfsAio *aiop) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            truncate(XrdSfsFileOffset fsize) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            getCXinfo(char cxtype[4], int &cxrsz) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual void           setXio(XrdSfsXio *xioP) { (void)xioP; }
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
                       XrdSfsFile(const char *user=0, int MonID=0)
                                 : error(*(new XrdOucErrInfo(user, MonID)))
                                 {lclEI = &error; pgwrEOF = 0;}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
                       XrdSfsFile(XrdSfsFile &wrapF)
                                 : error(wrapF.error), lclEI(0), pgwrEOF(0) {}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
                       XrdSfsFile(XrdOucErrInfo &eInfo)
                                 : error(eInfo), lclEI(0), pgwrEOF(0) {}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual               ~XrdSfsFile() {if (lclEI) delete lclEI;}
 
private:
XrdOucErrInfo*   lclEI;
XrdSfsFileOffset pgwrEOF;
}; // class XrdSfsFile
 
/******************************************************************************/
/*                      X r d S f s F i l e S y s t e m                       */
/******************************************************************************/
  
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
class XrdSfsFileSystem
{
public:
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsDirectory *newDir(char *user=0, int MonID=0)  = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsDirectory *newDir(XrdOucErrInfo &eInfo) {(void)eInfo; return 0;}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsFile      *newFile(char *user=0, int MonID=0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual XrdSfsFile      *newFile(XrdOucErrInfo &eInfo) {(void)eInfo; return 0;}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
enum    csFunc {csCalc = 0, csGet, csSize};
 
virtual int            chksum(      csFunc            Func,
                              const char             *csName,
                              const char             *path,
                                    XrdOucErrInfo    &eInfo,
                              const XrdSecEntity     *client = 0,
                              const char             *opaque = 0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            chmod(const char             *path,
                                   XrdSfsMode        mode,
                                   XrdOucErrInfo    &eInfo,
                             const XrdSecEntity     *client = 0,
                             const char             *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual void           Connect(const XrdSecEntity     *client = 0)
{
  (void)client;
}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual void           Disc(const XrdSecEntity *client = 0) {(void)client;}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual void           EnvInfo(XrdOucEnv *envP) {(void)envP;}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            exists(const char                *path,
                                    XrdSfsFileExistence &eFlag,
                                    XrdOucErrInfo       &eInfo,
                              const XrdSecEntity        *client = 0,
                              const char                *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            FAttr(      XrdSfsFACtl      *faReq,
                                   XrdOucErrInfo    &eInfo,
                             const XrdSecEntity     *client = 0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
        uint64_t       Features() {return FeatureSet;}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            FSctl(const int               cmd,
                                   XrdSfsFSctl      &args,
                                   XrdOucErrInfo    &eInfo,
                             const XrdSecEntity     *client = 0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            fsctl(const int               cmd,
                             const char             *args,
                                   XrdOucErrInfo    &eInfo,
                             const XrdSecEntity     *client = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            getChkPSize() {return 0;}
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            getStats(char *buff, int blen) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual const char    *getVersion() = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
enum gpfFunc {gpfCancel=0, 
              gpfGet,      
              gpfPut       
             };
 
virtual int            gpFile(      gpfFunc          &gpAct,
                                    XrdSfsGPFile     &gpReq,
                                    XrdOucErrInfo    &eInfo,
                              const XrdSecEntity     *client = 0);
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            mkdir(const char              *path,
                                   XrdSfsMode         mode,
                                   XrdOucErrInfo     &eInfo,
                             const XrdSecEntity      *client = 0,
                             const char              *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            prepare(      XrdSfsPrep      &pargs,
                                     XrdOucErrInfo   &eInfo,
                               const XrdSecEntity    *client = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            rem(const char                *path,
                                 XrdOucErrInfo       &eInfo,
                           const XrdSecEntity        *client = 0,
                           const char                *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            remdir(const char             *path,
                                    XrdOucErrInfo    &eInfo,
                              const XrdSecEntity     *client = 0,
                              const char             *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            rename(const char             *oPath,
                              const char             *nPath,
                                    XrdOucErrInfo    &eInfo,
                              const XrdSecEntity     *client = 0,
                              const char             *opaqueO = 0,
                              const char             *opaqueN = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            stat(const char               *Name,
                                  struct stat        *buf,
                                  XrdOucErrInfo      &eInfo,
                            const XrdSecEntity       *client = 0,
                            const char               *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            stat(const char               *path,
                                  mode_t             &mode,
                                  XrdOucErrInfo      &eInfo,
                            const XrdSecEntity       *client = 0,
                            const char               *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
virtual int            truncate(const char             *path,
                                      XrdSfsFileOffset  fsize,
                                      XrdOucErrInfo    &eInfo,
                                const XrdSecEntity     *client = 0,
                                const char             *opaque = 0) = 0;
 
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
 
                       XrdSfsFileSystem();
virtual               ~XrdSfsFileSystem() {}
 
protected:
 
uint64_t               FeatureSet; 
};
 
/******************************************************************************/
/*              F i l e   S y s t e m   I n s t a n t i a t o r               */
/******************************************************************************/
 
//-----------------------------------------------------------------------------
typedef XrdSfsFileSystem *(*XrdSfsFileSystem2_t)(XrdSfsFileSystem *nativeFS,
                                                 XrdSysLogger     *Logger,
                                                 const char       *configFn,
                                                 XrdOucEnv        *envP);
 
//-----------------------------------------------------------------------------
typedef XrdSfsFileSystem *(*XrdSfsFileSystem_t) (XrdSfsFileSystem *nativeFS,
                                                 XrdSysLogger     *Logger,
                                                 const char       *configFn);
 
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
#endif