TFile.h

Go to the documentation of this file.

// @(#)root/io:$Id$
// Author: Rene Brun   28/11/94

/*************************************************************************
 * 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_TFile
#define ROOT_TFile


//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TFile                                                                //
//                                                                      //
// ROOT file.                                                           //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

#include <atomic>

#include "TDirectoryFile.h"
#include "TMap.h"
#include "TUrl.h"

#ifdef R__USE_IMT
#include "ROOT/TRWSpinLock.hxx"
#include "ROOT/RConcurrentHashColl.hxx"
#include <mutex>
#endif


class TFree;
class TArrayC;
class TArchiveFile;
class TFileOpenHandle;
class TFileCacheRead;
class TFileCacheWrite;
class TProcessID;
class TStopwatch;
class TFilePrefetch;

class TFile : public TDirectoryFile {
  friend class TDirectoryFile;
  friend class TFilePrefetch;
// TODO: We need to make sure only one TBasket is being written at a time
// if we are writing multiple baskets in parallel.
#ifdef R__USE_IMT
  friend class TBasket;
#endif

public:
   /// Asynchronous open request status
   enum EAsyncOpenStatus { kAOSNotAsync = -1,  kAOSFailure = 0,
                           kAOSInProgress = 1, kAOSSuccess = 2 };
   /// Open timeout constants
   enum EOpenTimeOut { kInstantTimeout = 0, kEternalTimeout = 999999999 };

   /// TTreeCache flushing semantics
   enum ECacheAction { kDisconnect = 0, kDoNotDisconnect = 1 };

protected:
   Double_t         fSumBuffer;      ///<Sum of buffer sizes of objects written so far
   Double_t         fSum2Buffer;     ///<Sum of squares of buffer sizes of objects written so far
   Long64_t         fBytesWrite;     ///<Number of bytes written to this file
   Long64_t         fBytesRead;      ///<Number of bytes read from this file
   Long64_t         fBytesReadExtra; ///<Number of extra bytes (overhead) read by the readahead buffer
   Long64_t         fBEGIN;          ///<First used byte in file
   Long64_t         fEND;            ///<Last used byte in file
   Long64_t         fSeekFree;       ///<Location on disk of free segments structure
   Long64_t         fSeekInfo;       ///<Location on disk of StreamerInfo record
   Int_t            fD;              ///<File descriptor
   Int_t            fVersion;        ///<File format version
   Int_t            fCompress;       ///<Compression level and algorithm
   Int_t            fNbytesFree;     ///<Number of bytes for free segments structure
   Int_t            fNbytesInfo;     ///<Number of bytes for StreamerInfo record
   Int_t            fWritten;        ///<Number of objects written so far
   Int_t            fNProcessIDs;    ///<Number of TProcessID written to this file
   Int_t            fReadCalls;      ///<Number of read calls ( not counting the cache calls )
   TString          fRealName;       ///<Effective real file name (not original url)
   TString          fOption;         ///<File options
   Char_t           fUnits;          ///<Number of bytes for file pointers
   TList           *fFree;           ///<Free segments linked list table
   TArrayC         *fClassIndex;     ///<!Index of TStreamerInfo classes written to this file
   TObjArray       *fProcessIDs;     ///<!Array of pointers to TProcessIDs
   Long64_t         fOffset;         ///<!Seek offset cache
   TArchiveFile    *fArchive;        ///<!Archive file from which we read this file
   TFileCacheRead  *fCacheRead;      ///<!Pointer to the read cache (if any)
   TMap            *fCacheReadMap;   ///<!Pointer to the read cache (if any)
   TFileCacheWrite *fCacheWrite;     ///<!Pointer to the write cache (if any)
   Long64_t         fArchiveOffset;  ///<!Offset at which file starts in archive
   Bool_t           fIsArchive : 1;  ///<!True if this is a pure archive file
   Bool_t           fNoAnchorInName : 1; ///<!True if we don't want to force the anchor to be appended to the file name
   Bool_t           fIsRootFile : 1; ///<!True is this is a ROOT file, raw file otherwise
   Bool_t           fInitDone : 1;   ///<!True if the file has been initialized
   Bool_t           fMustFlush : 1;  ///<!True if the file buffers must be flushed
   Bool_t           fIsPcmFile : 1;  ///<!True if the file is a ROOT pcm file.
   TFileOpenHandle *fAsyncHandle;    ///<!For proper automatic cleanup
   EAsyncOpenStatus fAsyncOpenStatus; ///<!Status of an asynchronous open request
   TUrl             fUrl;            ///<!URL of file

   TList           *fInfoCache;      ///<!Cached list of the streamer infos in this file
   TList           *fOpenPhases;     ///<!Time info about open phases

#ifdef R__USE_IMT
   static ROOT::TRWSpinLock                   fgRwLock;     ///<!Read-write lock to protect global PID list
   std::mutex                                 fWriteMutex;  ///<!Lock for writing baskets / keys into the file.
   static ROOT::Internal::RConcurrentHashColl fgTsSIHashes; ///<!TS Set of hashes built from read streamer infos
#endif

   static TList    *fgAsyncOpenRequests; //List of handles for pending open requests

   static TString   fgCacheFileDir;          ///<Directory where to locally stage files
   static Bool_t    fgCacheFileDisconnected; ///<Indicates, we trust in the files in the cache dir without stat on the cached file
   static Bool_t    fgCacheFileForce;        ///<Indicates, to force all READ to CACHEREAD
   static UInt_t    fgOpenTimeout;           ///<Timeout for open operations in ms  - 0 corresponds to blocking i/o
   static Bool_t    fgOnlyStaged ;           ///<Before the file is opened, it is checked, that the file is staged, if not, the open fails

   static std::atomic<Long64_t>  fgBytesWrite;            ///<Number of bytes written by all TFile objects
   static std::atomic<Long64_t>  fgBytesRead;             ///<Number of bytes read by all TFile objects
   static std::atomic<Long64_t>  fgFileCounter;           ///<Counter for all opened files
   static std::atomic<Int_t>     fgReadCalls;             ///<Number of bytes read from all TFile objects
   static Int_t     fgReadaheadSize;         ///<Readahead buffer size
   static Bool_t    fgReadInfo;              ///<if true (default) ReadStreamerInfo is called when opening a file
   virtual EAsyncOpenStatus GetAsyncOpenStatus() { return fAsyncOpenStatus; }
   virtual void  Init(Bool_t create);
   Bool_t                    FlushWriteCache();
   Int_t                     ReadBufferViaCache(char *buf, Int_t len);
   Int_t                     WriteBufferViaCache(const char *buf, Int_t len);
   std::pair<TList *, Int_t> GetStreamerInfoListImpl(bool readSI);

   // Creating projects
   Int_t         MakeProjectParMake(const char *packname, const char *filename);
   Int_t         MakeProjectParProofInf(const char *packname, const char *proofinfdir);

   // Interface to basic system I/O routines
   virtual Int_t    SysOpen(const char *pathname, Int_t flags, UInt_t mode);
   virtual Int_t    SysClose(Int_t fd);
   virtual Int_t    SysRead(Int_t fd, void *buf, Int_t len);
   virtual Int_t    SysWrite(Int_t fd, const 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);

   // Interface for text-based TDirectory I/O
   virtual Long64_t DirCreateEntry(TDirectory*) { return 0; }
   virtual Int_t    DirReadKeys(TDirectory*) { return 0; }
   virtual void     DirWriteKeys(TDirectory*) {}
   virtual void     DirWriteHeader(TDirectory*) {}

private:
   TFile(const TFile &);            //Files cannot be copied
   void operator=(const TFile &);

   static void   CpProgress(Long64_t bytesread, Long64_t size, TStopwatch &watch);
   static TFile *OpenFromCache(const char *name, Option_t * = "",
                               const char *ftitle = "", Int_t compress = 1,
                               Int_t netopt = 0);

public:
   /// TFile status bits. BIT(13) is taken up by TObject
   enum EStatusBits {
      kRecovered     = BIT(10),
      kHasReferences = BIT(11),
      kDevNull       = BIT(12),
      kWriteError    = BIT(14),
      kBinaryFile    = BIT(15),
      kRedirected    = BIT(16)
   };
   enum ERelativeTo { kBeg = 0, kCur = 1, kEnd = 2 };
   enum { kStartBigFile  = 2000000000 };
   /// File type
   enum EFileType { kDefault = 0, kLocal = 1, kNet = 2, kWeb = 3, kFile = 4, kMerge = 5};

   TFile();
   TFile(const char *fname, Option_t *option="", const char *ftitle="", Int_t compress=4);
   virtual ~TFile();
   virtual void        Close(Option_t *option=""); // *MENU*
   virtual void        Copy(TObject &) const { MayNotUse("Copy(TObject &)"); }
   virtual Bool_t      Cp(const char *dst, Bool_t progressbar = kTRUE,UInt_t buffersize = 1000000);
   virtual TKey*       CreateKey(TDirectory* mother, const TObject* obj, const char* name, Int_t bufsize);
   virtual TKey*       CreateKey(TDirectory* mother, const void* obj, const TClass* cl,
                                 const char* name, Int_t bufsize);
   static TFile      *&CurrentFile(); // Return the current file for this thread.
   virtual void        Delete(const char *namecycle="");
   virtual void        Draw(Option_t *option="");
   virtual void        DrawMap(const char *keys="*",Option_t *option=""); // *MENU*
   virtual void        FillBuffer(char *&buffer);
   virtual void        Flush();
   TArchiveFile       *GetArchive() const { return fArchive; }
   Long64_t            GetArchiveOffset() const { return fArchiveOffset; }
   Int_t               GetBestBuffer() const;
   virtual Int_t       GetBytesToPrefetch() const;
   TFileCacheRead     *GetCacheRead(TObject* tree = 0) const;
   TFileCacheWrite    *GetCacheWrite() const;
   TArrayC            *GetClassIndex() const { return fClassIndex; }
   Int_t               GetCompressionAlgorithm() const;
   Int_t               GetCompressionLevel() const;
   Int_t               GetCompressionSettings() const;
   Float_t             GetCompressionFactor();
   virtual Long64_t    GetEND() const { return fEND; }
   virtual Int_t       GetErrno() const;
   virtual void        ResetErrno() const;
   Int_t               GetFd() const { return fD; }
   virtual const TUrl *GetEndpointUrl() const { return &fUrl; }
   TObjArray          *GetListOfProcessIDs() const {return fProcessIDs;}
   TList              *GetListOfFree() const { return fFree; }
   virtual Int_t       GetNfree() const { return fFree->GetSize(); }
   virtual Int_t       GetNProcessIDs() const { return fNProcessIDs; }
   Option_t           *GetOption() const { return fOption.Data(); }
   virtual Long64_t    GetBytesRead() const { return fBytesRead; }
   virtual Long64_t    GetBytesReadExtra() const { return fBytesReadExtra; }
   virtual Long64_t    GetBytesWritten() const;
   virtual Int_t       GetReadCalls() const { return fReadCalls; }
   Int_t               GetVersion() const { return fVersion; }
   Int_t               GetRecordHeader(char *buf, Long64_t first, Int_t maxbytes,
                                       Int_t &nbytes, Int_t &objlen, Int_t &keylen);
   virtual Int_t       GetNbytesInfo() const {return fNbytesInfo;}
   virtual Int_t       GetNbytesFree() const {return fNbytesFree;}
   virtual TString     GetNewUrl() { return ""; }
   Long64_t            GetRelOffset() const { return fOffset - fArchiveOffset; }
   virtual Long64_t    GetSeekFree() const {return fSeekFree;}
   virtual Long64_t    GetSeekInfo() const {return fSeekInfo;}
   virtual Long64_t    GetSize() const;
   virtual TList      *GetStreamerInfoList();
   const   TList      *GetStreamerInfoCache();
   virtual void        IncrementProcessIDs() { fNProcessIDs++; }
   virtual Bool_t      IsArchive() const { return fIsArchive; }
           Bool_t      IsBinary() const { return TestBit(kBinaryFile); }
           Bool_t      IsRaw() const { return !fIsRootFile; }
   virtual Bool_t      IsOpen() const;
   virtual void        ls(Option_t *option="") const;
   virtual void        MakeFree(Long64_t first, Long64_t last);
   virtual void        MakeProject(const char *dirname, const char *classes="*",
                                   Option_t *option="new"); // *MENU*
   virtual void        Map(Option_t *opt); // *MENU*
   virtual void        Map() { Map(""); }; // *MENU*
   virtual Bool_t      Matches(const char *name);
   virtual Bool_t      MustFlush() const {return fMustFlush;}
   virtual void        Paint(Option_t *option="");
   virtual void        Print(Option_t *option="") const;
   virtual Bool_t      ReadBufferAsync(Long64_t offs, Int_t len);
   virtual Bool_t      ReadBuffer(char *buf, Int_t len);
   virtual Bool_t      ReadBuffer(char *buf, Long64_t pos, Int_t len);
   virtual Bool_t      ReadBuffers(char *buf, Long64_t *pos, Int_t *len, Int_t nbuf);
   virtual void        ReadFree();
   virtual TProcessID *ReadProcessID(UShort_t pidf);
   virtual void        ReadStreamerInfo();
   virtual Int_t       Recover();
   virtual Int_t       ReOpen(Option_t *mode);
   virtual void        Seek(Long64_t offset, ERelativeTo pos = kBeg);
   virtual void        SetCacheRead(TFileCacheRead *cache, TObject* tree = 0, ECacheAction action = kDisconnect);
   virtual void        SetCacheWrite(TFileCacheWrite *cache);
   virtual void        SetCompressionAlgorithm(Int_t algorithm=0);
   virtual void        SetCompressionLevel(Int_t level=4);
   virtual void        SetCompressionSettings(Int_t settings=4);
   virtual void        SetEND(Long64_t last) { fEND = last; }
   virtual void        SetOffset(Long64_t offset, ERelativeTo pos = kBeg);
   virtual void        SetOption(Option_t *option=">") { fOption = option; }
   virtual void        SetReadCalls(Int_t readcalls = 0) { fReadCalls = readcalls; }
   virtual void        ShowStreamerInfo();
   virtual Int_t       Sizeof() const;
   void                SumBuffer(Int_t bufsize);
   virtual Bool_t      WriteBuffer(const char *buf, Int_t len);
   virtual Int_t       Write(const char *name=0, Int_t opt=0, Int_t bufsiz=0);
   virtual Int_t       Write(const char *name=0, Int_t opt=0, Int_t bufsiz=0) const;
   virtual void        WriteFree();
   virtual void        WriteHeader();
   virtual UShort_t    WriteProcessID(TProcessID *pid);
   virtual void        WriteStreamerInfo();

   static TFileOpenHandle
                      *AsyncOpen(const char *name, Option_t *option = "",
                                 const char *ftitle = "", Int_t compress = 1,
                                 Int_t netopt = 0);
   static TFile       *Open(const char *name, Option_t *option = "",
                            const char *ftitle = "", Int_t compress = 1,
                            Int_t netopt = 0);
   static TFile       *Open(TFileOpenHandle *handle);

   static EFileType    GetType(const char *name, Option_t *option = "", TString *prefix = 0);

   static EAsyncOpenStatus GetAsyncOpenStatus(const char *name);
   static EAsyncOpenStatus GetAsyncOpenStatus(TFileOpenHandle *handle);
   static const TUrl  *GetEndpointUrl(const char *name);

   static Long64_t     GetFileBytesRead();
   static Long64_t     GetFileBytesWritten();
   static Int_t        GetFileReadCalls();
   static Int_t        GetReadaheadSize();

   static void         SetFileBytesRead(Long64_t bytes = 0);
   static void         SetFileBytesWritten(Long64_t bytes = 0);
   static void         SetFileReadCalls(Int_t readcalls = 0);
   static void         SetReadaheadSize(Int_t bufsize = 256000);
   static void         SetReadStreamerInfo(Bool_t readinfo=kTRUE);
   static Bool_t       GetReadStreamerInfo();

   static Long64_t     GetFileCounter();
   static void         IncrementFileCounter();

   static Bool_t       SetCacheFileDir(ROOT::Internal::TStringView cacheDir, Bool_t operateDisconnected = kTRUE,
                                       Bool_t forceCacheread = kFALSE)
     { return SetCacheFileDir(std::string_view(cacheDir), operateDisconnected, forceCacheread); }
   static Bool_t       SetCacheFileDir(std::string_view cacheDir, Bool_t operateDisconnected = kTRUE,
                                       Bool_t forceCacheread = kFALSE);
   static const char  *GetCacheFileDir();
   static Bool_t       ShrinkCacheFileDir(Long64_t shrinkSize, Long_t cleanupInteval = 0);
   static Bool_t       Cp(const char *src, const char *dst, Bool_t progressbar = kTRUE,
                          UInt_t buffersize = 1000000);

   static UInt_t       SetOpenTimeout(UInt_t timeout);  // in ms
   static UInt_t       GetOpenTimeout(); // in ms
   static Bool_t       SetOnlyStaged(Bool_t onlystaged);
   static Bool_t       GetOnlyStaged();

   ClassDef(TFile,8)  //ROOT file
};

#ifndef __CINT__
#define gFile (TFile::CurrentFile())

#elif defined(__MAKECINT__)
// To properly handle the use of gFile in header files (in static declarations)
R__EXTERN TFile   *gFile;
#endif

/**
\class TFileOpenHandle
\ingroup IO
Class holding info about the file being opened
*/
class TFileOpenHandle : public TNamed {

friend class TFile;
friend class TAlienFile;

private:
   TString  fOpt;        ///< Options
   Int_t    fCompress;   ///< Compression level and algorithm
   Int_t    fNetOpt;     ///< Network options
   TFile   *fFile;       ///< TFile instance of the file being opened

   TFileOpenHandle(TFile *f) : TNamed("",""), fOpt(""), fCompress(1),
                               fNetOpt(0), fFile(f) { }
   TFileOpenHandle(const char *n, const char *o, const char *t, Int_t cmp,
                   Int_t no) : TNamed(n,t), fOpt(o), fCompress(cmp),
                               fNetOpt(no), fFile(0) { }
   TFileOpenHandle(const TFileOpenHandle&);
   TFileOpenHandle& operator=(const TFileOpenHandle&);

   TFile      *GetFile() const { return fFile; }

public:
   ~TFileOpenHandle() { }

   Bool_t      Matches(const char *name);

   const char *GetOpt() const { return fOpt; }
   Int_t       GetCompress() const { return fCompress; }
   Int_t       GetNetOpt() const { return fNetOpt; }
};

//______________________________________________________________________________
inline Int_t TFile::GetCompressionAlgorithm() const
{
   return (fCompress < 0) ? -1 : fCompress / 100;
}

//______________________________________________________________________________
inline Int_t TFile::GetCompressionLevel() const
{
   return (fCompress < 0) ? -1 : fCompress % 100;
}

//______________________________________________________________________________
inline Int_t TFile::GetCompressionSettings() const
{
   return (fCompress < 0) ? -1 : fCompress;
}

#endif