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ROOT
Reference Guide |
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ROOT
Reference Guide |
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A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
If the key is located past the 32 bit file limit (> 2 GB) then some fields will be 8 instead of 4 bytes:
| Byte Range | Member Name | Description |
|---|---|---|
| 1->4 | Nbytes | Length of compressed object (in bytes) |
| 5->6 | Version | TKey version identifier |
| 7->10 | ObjLen | Length of uncompressed object |
| 11->14 | Datime | Date and time when object was written to file |
| 15->16 | KeyLen | Length of the key structure (in bytes) |
| 17->18 | Cycle | Cycle of key |
| 19->22 [19->26] | SeekKey | Pointer to record itself (consistency check) |
| 23->26 [27->34] | SeekPdir | Pointer to directory header |
| 27->27 [35->35] | lname | Number of bytes in the class name |
| 28->.. [36->..] | ClassName | Object Class Name |
| ..->.. | lname | Number of bytes in the object name |
| ..->.. | Name | lName bytes with the name of the object |
| ..->.. | lTitle | Number of bytes in the object title |
| ..->.. | Title | Title of the object |
| --—> | DATA | Data bytes associated to the object |
The first data record starts at byte fBEGIN (currently set to kBEGIN). Bytes 1->kBEGIN contain the file description, when fVersion >= 1000000 it is a large file (> 2 GB) and the offsets will be 8 bytes long and fUnits will be set to 8:
| Byte Range | Record Name | Description |
|---|---|---|
| 1->4 | "root" | Root file identifier |
| 5->8 | fVersion | File format version |
| 9->12 | fBEGIN | Pointer to first data record |
| 13->16 [13->20] | fEND | Pointer to first free word at the EOF |
| 17->20 [21->28] | fSeekFree | Pointer to FREE data record |
| 21->24 [29->32] | fNbytesFree | Number of bytes in FREE data record |
| 25->28 [33->36] | nfree | Number of free data records |
| 29->32 [37->40] | fNbytesName | Number of bytes in TNamed at creation time |
| 33->33 [41->41] | fUnits | Number of bytes for file pointers |
| 34->37 [42->45] | fCompress | Compression level and algorithm |
| 38->41 [46->53] | fSeekInfo | Pointer to TStreamerInfo record |
| 42->45 [54->57] | fNbytesInfo | Number of bytes in TStreamerInfo record |
| 46->63 [58->75] | fUUID | Universal Unique ID |
The structure of a directory is shown in TDirectoryFile::TDirectoryFile
In the same way as for TDirectory, it is possible to inspect the content of a TFile object from Python as if the directories and objects it contains were its attributes. For more information, please refer to the TDirectory documentation.
In addition, TFile instances can be inspected via the Get method, a feature that is inherited from TDirectoryFile (please see the documentation of TDirectoryFile for examples on how to use it).
In order to write objects into a TFile, the WriteObject Python method can be used (more information in the documentation of TDirectoryFile).
Finally, PyROOT modifies the TFile constructor and the TFile::Open method to make them behave in a more pythonic way. In particular, they both throw an OSError if there was a problem accessing the file (e.g. non-existent or corrupted file).
Classes | |
| struct | InfoListRet |
| Simple struct of the return value of GetStreamerInfoListImpl. More... | |
Public Types | |
| enum | { kStartBigFile = 2000000000 } |
| enum | EAsyncOpenStatus { kAOSNotAsync = -1 , kAOSFailure = 0 , kAOSInProgress = 1 , kAOSSuccess = 2 } |
| Asynchronous open request status. More... | |
| enum | ECacheAction { kDisconnect = 0 , kDoNotDisconnect = 1 } |
| TTreeCache flushing semantics. More... | |
| enum | EFileType { kDefault = 0 , kLocal = 1 , kNet = 2 , kWeb = 3 , kFile = 4 , kMerge = 5 } |
| File type. More... | |
| enum | EOpenTimeOut { kInstantTimeout = 0 , kEternalTimeout = 999999999 } |
| Open timeout constants. More... | |
| enum | ERelativeTo { kBeg = 0 , kCur = 1 , kEnd = 2 } |
| enum | EStatusBits { kRecovered = BIT(10) , kHasReferences = BIT(11) , kDevNull = BIT(12) , kWriteError = BIT(14) , kBinaryFile = BIT(15) , kRedirected = BIT(16) , kReproducible = BIT(17) } |
| TFile status bits. BIT(13) is taken up by TObject. More... | |
 Public Types inherited from TDirectoryFile | |
| enum | EStatusBits { kCloseDirectory = BIT(7) } |
| Public Types inherited from TObject | |
| enum | { kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 , kBitMask = 0x00ffffff } |
| enum | { kSingleKey = BIT(0) , kOverwrite = BIT(1) , kWriteDelete = BIT(2) } |
| enum | EDeprecatedStatusBits { kObjInCanvas = BIT(3) } |
| enum | EStatusBits { kCanDelete = BIT(0) , kMustCleanup = BIT(3) , kIsReferenced = BIT(4) , kHasUUID = BIT(5) , kCannotPick = BIT(6) , kNoContextMenu = BIT(8) , kInvalidObject = BIT(13) } |
Public Member Functions | |
| TFile () | |
| File default Constructor. | |
| TFile (const char *fname, Option_t *option="", const char *ftitle="", Int_t compress=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault) | |
| Opens or creates a local ROOT file. | |
| virtual | ~TFile () |
| File destructor. | |
| void | Close (Option_t *option="") override |
| Close a file. | |
| void | Copy (TObject &) const override |
| Copy this to obj. | |
| virtual Bool_t | Cp (const char *dst, Bool_t progressbar=kTRUE, UInt_t buffersize=1000000) |
| Allows to copy this file to the dst URL. | |
| virtual TKey * | CreateKey (TDirectory *mother, const TObject *obj, const char *name, Int_t bufsize) |
| Creates key for object and converts data to buffer. | |
| virtual TKey * | CreateKey (TDirectory *mother, const void *obj, const TClass *cl, const char *name, Int_t bufsize) |
| Creates key for object and converts data to buffer. | |
| void | Delete (const char *namecycle="") override |
| Delete object namecycle. | |
| void | Draw (Option_t *option="") override |
| Fill Graphics Structure and Paint. | |
| virtual void | DrawMap (const char *keys="*", Option_t *option="") |
| Draw map of objects in this file. | |
| void | FillBuffer (char *&buffer) override |
| Encode file output buffer. | |
| virtual void | Flush () |
| Synchronize a file's in-memory and on-disk states. | |
| TArchiveFile * | GetArchive () const |
| Long64_t | GetArchiveOffset () const |
| Int_t | GetBestBuffer () const |
| Return the best buffer size of objects on this file. | |
| virtual Long64_t | GetBytesRead () const |
| virtual Long64_t | GetBytesReadExtra () const |
| virtual Int_t | GetBytesToPrefetch () const |
| Max number of bytes to prefetch. | |
| virtual Long64_t | GetBytesWritten () const |
| Return the total number of bytes written so far to the file. | |
| TFileCacheRead * | GetCacheRead (const TObject *tree=nullptr) const |
| Return a pointer to the current read cache. | |
| TFileCacheWrite * | GetCacheWrite () const |
| Return a pointer to the current write cache. | |
| TArrayC * | GetClassIndex () const |
| Int_t | GetCompressionAlgorithm () const |
| Float_t | GetCompressionFactor () |
| Return the file compression factor. | |
| Int_t | GetCompressionLevel () const |
| Int_t | GetCompressionSettings () const |
| virtual Long64_t | GetEND () const |
| virtual const TUrl * | GetEndpointUrl () const |
| virtual Int_t | GetErrno () const |
| Method returning errno. | |
| Int_t | GetFd () const |
| TList * | GetListOfFree () const |
| TObjArray * | GetListOfProcessIDs () const |
| virtual Int_t | GetNbytesFree () const |
| virtual Int_t | GetNbytesInfo () const |
| virtual TString | GetNewUrl () |
| virtual Int_t | GetNfree () const |
| virtual Int_t | GetNProcessIDs () const |
| Option_t * | GetOption () const override |
| virtual Int_t | GetReadCalls () const |
| Int_t | GetRecordHeader (char *buf, Long64_t first, Int_t maxbytes, Int_t &nbytes, Int_t &objlen, Int_t &keylen) |
| Read the logical record header starting at a certain postion. | |
| Long64_t | GetRelOffset () const |
| virtual Long64_t | GetSeekFree () const |
| virtual Long64_t | GetSeekInfo () const |
| virtual Long64_t | GetSize () const |
| Returns the current file size. | |
| const TList * | GetStreamerInfoCache () |
| Returns the cached list of StreamerInfos used in this file. | |
| virtual TList * | GetStreamerInfoList () final |
| Read the list of TStreamerInfo objects written to this file. | |
| Int_t | GetVersion () const |
| virtual void | IncrementProcessIDs () |
| virtual Bool_t | IsArchive () const |
| Bool_t | IsBinary () const |
| virtual Bool_t | IsOpen () const |
| Returns kTRUE in case file is open and kFALSE if file is not open. | |
| Bool_t | IsRaw () const |
| void | ls (Option_t *option="") const override |
| List file contents. | |
| virtual void | MakeFree (Long64_t first, Long64_t last) |
| Mark unused bytes on the file. | |
| virtual void | MakeProject (const char *dirname, const char *classes="*", Option_t *option="new") |
| Generate source code necessary to access the objects stored in the file. | |
| virtual void | Map () |
| virtual void | Map (Option_t *opt) |
| List the contents of a file sequentially. | |
| virtual Bool_t | Matches (const char *name) |
| Return kTRUE if 'url' matches the coordinates of this file. | |
| virtual Bool_t | MustFlush () const |
| void | Paint (Option_t *option="") override |
| Paint all objects in the file. | |
| void | Print (Option_t *option="") const override |
| Print all objects in the file. | |
| virtual Bool_t | ReadBuffer (char *buf, Int_t len) |
| Read a buffer from the file. | |
| virtual Bool_t | ReadBuffer (char *buf, Long64_t pos, Int_t len) |
| Read a buffer from the file at the offset 'pos' in the file. | |
| virtual Bool_t | ReadBufferAsync (Long64_t offs, Int_t len) |
| virtual Bool_t | ReadBuffers (char *buf, Long64_t *pos, Int_t *len, Int_t nbuf) |
| Read the nbuf blocks described in arrays pos and len. | |
| virtual void | ReadFree () |
| Read the FREE linked list. | |
| virtual TProcessID * | ReadProcessID (UShort_t pidf) |
| The TProcessID with number pidf is read from this file. | |
| virtual void | ReadStreamerInfo () |
| Read the list of StreamerInfo from this file. | |
| virtual Int_t | Recover () |
| Attempt to recover file if not correctly closed. | |
| virtual Int_t | ReOpen (Option_t *mode) |
| Reopen a file with a different access mode. | |
| virtual void | ResetErrno () const |
| Method resetting the errno. | |
| virtual void | Seek (Long64_t offset, ERelativeTo pos=kBeg) |
| Seek to a specific position in the file. Pos it either kBeg, kCur or kEnd. | |
| virtual void | SetCacheRead (TFileCacheRead *cache, TObject *tree=0, ECacheAction action=kDisconnect) |
| Set a pointer to the read cache. | |
| virtual void | SetCacheWrite (TFileCacheWrite *cache) |
| Set a pointer to the write cache. | |
| virtual void | SetCompressionAlgorithm (Int_t algorithm=ROOT::RCompressionSetting::EAlgorithm::kUseGlobal) |
| See comments for function SetCompressionSettings. | |
| virtual void | SetCompressionLevel (Int_t level=ROOT::RCompressionSetting::ELevel::kUseMin) |
| See comments for function SetCompressionSettings. | |
| virtual void | SetCompressionSettings (Int_t settings=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault) |
| Used to specify the compression level and algorithm. | |
| virtual void | SetEND (Long64_t last) |
| virtual void | SetOffset (Long64_t offset, ERelativeTo pos=kBeg) |
| Set position from where to start reading. | |
| virtual void | SetOption (Option_t *option=">") |
| virtual void | SetReadCalls (Int_t readcalls=0) |
| virtual void | ShowStreamerInfo () |
| Show the StreamerInfo of all classes written to this file. | |
| Int_t | Sizeof () const override |
| Return the size in bytes of the file header. | |
| void | SumBuffer (Int_t bufsize) |
| Increment statistics for buffer sizes of objects in this file. | |
| Int_t | Write (const char *name=nullptr, Int_t opt=0, Int_t bufsiz=0) const override |
| One can not save a const TDirectory object. | |
| Int_t | Write (const char *name=nullptr, Int_t opt=0, Int_t bufsiz=0) override |
| Write memory objects to this file. | |
| virtual Bool_t | WriteBuffer (const char *buf, Int_t len) |
| Write a buffer to the file. | |
| virtual void | WriteFree () |
| Write FREE linked list on the file. | |
| virtual void | WriteHeader () |
| Write File Header. | |
| virtual UShort_t | WriteProcessID (TProcessID *pid) |
| Check if the ProcessID pidd is already in the file, if not, add it and return the index number in the local file list. | |
| virtual void | WriteStreamerInfo () |
| Write the list of TStreamerInfo as a single object in this file The class Streamer description for all classes written to this file is saved. | |
| Public Member Functions inherited from TDirectoryFile | |
| TDirectoryFile () | |
| Default TDirectoryFile constructor. | |
| TDirectoryFile (const char *name, const char *title, Option_t *option="", TDirectory *motherDir=nullptr) | |
| Create a new TDirectoryFile. | |
| virtual | ~TDirectoryFile () |
| Destructor. | |
| void | Add (TObject *obj, Bool_t replace=kFALSE) override |
| void | Append (TObject *obj, Bool_t replace=kFALSE) override |
| Append object to this directory. | |
| Int_t | AppendKey (TKey *key) override |
| Insert key in the linked list of keys of this directory. | |
| void | Browse (TBrowser *b) override |
| Browse the content of the directory. | |
| void | Build (TFile *motherFile=nullptr, TDirectory *motherDir=nullptr) override |
| Bool_t | cd (const char *path=nullptr) override |
| Change current directory to "this" directory. | |
| TObject * | CloneObject (const TObject *obj, Bool_t autoadd=kTRUE) override |
| Make a clone of an object using the Streamer facility. | |
| TKey * | FindKey (const char *keyname) const override |
| Find key with name keyname in the current directory. | |
| TKey * | FindKeyAny (const char *keyname) const override |
| Find key with name keyname in the current directory or its subdirectories. | |
| TObject * | FindObjectAny (const char *name) const override |
| Find object by name in the list of memory objects of the current directory or its sub-directories. | |
| TObject * | FindObjectAnyFile (const char *name) const override |
| Scan the memory lists of all files for an object with name. | |
| template<class T > | |
| T * | Get (const char *namecycle) |
| See documentation of TDirectoryFile::Get(const char *namecycle) | |
| TObject * | Get (const char *namecycle) override |
| Return pointer to object identified by namecycle. | |
| Int_t | GetBufferSize () const override |
| Return the buffer size to create new TKeys. | |
| const TDatime & | GetCreationDate () const |
| TDirectory * | GetDirectory (const char *apath, Bool_t printError=false, const char *funcname="GetDirectory") override |
| Find a directory named "apath". | |
| TFile * | GetFile () const override |
| TKey * | GetKey (const char *name, Short_t cycle=9999) const override |
| Return pointer to key with name,cycle. | |
| TList * | GetListOfKeys () const override |
| const TDatime & | GetModificationDate () const |
| Int_t | GetNbytesKeys () const override |
| Int_t | GetNkeys () const override |
| void * | GetObjectChecked (const char *namecycle, const char *classname) override |
| See documentation of TDirectoryFile::GetObjectCheck(const char *namecycle, const TClass *cl) | |
| void * | GetObjectChecked (const char *namecycle, const TClass *cl) override |
| Return pointer to object identified by namecycle if and only if the actual object is a type suitable to be stored as a pointer to a "expectedClass" If expectedClass is null, no check is performed. | |
| void * | GetObjectUnchecked (const char *namecycle) override |
| Return pointer to object identified by namecycle. | |
| Long64_t | GetSeekDir () const override |
| Long64_t | GetSeekKeys () const override |
| Long64_t | GetSeekParent () const override |
| Bool_t | IsModified () const override |
| Bool_t | IsWritable () const override |
| TDirectory * | mkdir (const char *name, const char *title="", Bool_t returnExistingDirectory=kFALSE) override |
| Create a sub-directory "a" or a hierarchy of sub-directories "a/b/c/...". | |
| TFile * | OpenFile (const char *name, Option_t *option="", const char *ftitle="", Int_t compress=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault, Int_t netopt=0) override |
| Interface to TFile::Open. | |
| void | Purge (Short_t nkeep=1) override |
| Purge lowest key cycles in a directory. | |
| void | ReadAll (Option_t *option="") override |
| Read objects from a ROOT file directory into memory. | |
| Int_t | ReadKeys (Bool_t forceRead=kTRUE) override |
| Read the linked list of keys. | |
| Int_t | ReadTObject (TObject *obj, const char *keyname) override |
| Read object with keyname from the current directory. | |
| virtual void | ResetAfterMerge (TFileMergeInfo *) |
| Reset the TDirectory after its content has been merged into another Directory. | |
| void | rmdir (const char *name) override |
| Removes subdirectory from the directory. | |
| void | Save () override |
| Save recursively all directory keys and headers. | |
| Int_t | SaveObjectAs (const TObject *obj, const char *filename="", Option_t *option="") const override |
| Save object in filename. | |
| void | SaveSelf (Bool_t force=kFALSE) override |
| Save Directory keys and header. | |
| void | SetBufferSize (Int_t bufsize) override |
| Set the default buffer size when creating new TKeys. | |
| void | SetModified () override |
| void | SetSeekDir (Long64_t v) override |
| void | SetTRefAction (TObject *ref, TObject *parent) override |
| Find the action to be executed in the dictionary of the parent class and store the corresponding exec number into fBits. | |
| void | SetWritable (Bool_t writable=kTRUE) override |
| Set the new value of fWritable recursively. | |
| void | WriteDirHeader () override |
| Overwrite the Directory header record. | |
| void | WriteKeys () override |
| Write Keys linked list on the file. | |
| Int_t | WriteObjectAny (const void *obj, const char *classname, const char *name, Option_t *option="", Int_t bufsize=0) override |
| Write object from pointer of class classname in this directory. | |
| Int_t | WriteObjectAny (const void *obj, const TClass *cl, const char *name, Option_t *option="", Int_t bufsize=0) override |
| Write object of class with dictionary cl in this directory. | |
| Int_t | WriteTObject (const TObject *obj, const char *name=nullptr, Option_t *option="", Int_t bufsize=0) override |
| Write object obj to this directory. | |
| Public Member Functions inherited from TDirectory | |
| TDirectory () | |
| Directory default constructor. | |
| TDirectory (const char *name, const char *title, Option_t *option="", TDirectory *motherDir=nullptr) | |
| Create a new Directory. | |
| virtual | ~TDirectory () |
| Destructor. | |
| void | Clear (Option_t *option="") override |
| Delete all objects from a Directory list. | |
| virtual void | DeleteAll (Option_t *option="") |
| Delete all objects from memory. | |
| TObject * | FindObject (const char *name) const override |
| Find object by name in the list of memory objects. | |
| TObject * | FindObject (const TObject *obj) const override |
| Find object in the list of memory objects. | |
| template<class T > | |
| T * | Get (const char *namecycle) |
| See documentation of TDirectoryFile::Get(const char *namecycle) | |
| virtual TList * | GetList () const |
| TObject * | GetMother () const |
| TDirectory * | GetMotherDir () const |
| template<class T > | |
| void | GetObject (const char *namecycle, T *&ptr) |
| Get an object with proper type checking. | |
| virtual const char * | GetPath () const |
| Returns the full path of the directory. | |
| virtual const char * | GetPathStatic () const |
| Returns the full path of the directory. | |
| TUUID | GetUUID () const |
| Bool_t | IsFolder () const override |
| Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). | |
| virtual void | pwd () const |
| Print the path of the directory. | |
| void | RecursiveRemove (TObject *obj) override |
| Recursively remove object from a Directory. | |
| virtual TObject * | Remove (TObject *) |
| Remove an object from the in-memory list. | |
| virtual void | SetMother (TObject *mother) |
| void | SetName (const char *newname) override |
| Set the name for directory If the directory name is changed after the directory was written once, ROOT currently would NOT change the name of correspondent key in the mother directory. | |
| template<class T > | |
| Int_t | WriteObject (const T *obj, const char *name, Option_t *option="", Int_t bufsize=0) |
| Write an object with proper type checking. | |
| Public Member Functions inherited from TNamed | |
| TNamed () | |
| TNamed (const char *name, const char *title) | |
| TNamed (const TNamed &named) | |
| TNamed copy ctor. | |
| TNamed (const TString &name, const TString &title) | |
| virtual | ~TNamed () |
| TNamed destructor. | |
| virtual TObject * | Clone (const char *newname="") const |
| Make a clone of an object using the Streamer facility. | |
| virtual Int_t | Compare (const TObject *obj) const |
| Compare two TNamed objects. | |
| virtual const char * | GetName () const |
| Returns name of object. | |
| virtual const char * | GetTitle () const |
| Returns title of object. | |
| virtual ULong_t | Hash () const |
| Return hash value for this object. | |
| virtual Bool_t | IsSortable () const |
| TNamed & | operator= (const TNamed &rhs) |
| TNamed assignment operator. | |
| virtual void | SetNameTitle (const char *name, const char *title) |
| Set all the TNamed parameters (name and title). | |
| virtual void | SetTitle (const char *title="") |
| Set the title of the TNamed. | |
| Public Member Functions inherited from TObject | |
| TObject () | |
| TObject constructor. | |
| TObject (const TObject &object) | |
| TObject copy ctor. | |
| virtual | ~TObject () |
| TObject destructor. | |
| void | AbstractMethod (const char *method) const |
| Use this method to implement an "abstract" method that you don't want to leave purely abstract. | |
| virtual void | AppendPad (Option_t *option="") |
| Append graphics object to current pad. | |
| ULong_t | CheckedHash () |
| Check and record whether this class has a consistent Hash/RecursiveRemove setup (*) and then return the regular Hash value for this object. | |
| virtual const char * | ClassName () const |
| Returns name of class to which the object belongs. | |
| virtual Int_t | DistancetoPrimitive (Int_t px, Int_t py) |
| Computes distance from point (px,py) to the object. | |
| virtual void | DrawClass () const |
| Draw class inheritance tree of the class to which this object belongs. | |
| virtual TObject * | DrawClone (Option_t *option="") const |
Draw a clone of this object in the current selected pad for instance with: gROOT->SetSelectedPad(gPad). | |
| virtual void | Dump () const |
| Dump contents of object on stdout. | |
| virtual void | Error (const char *method, const char *msgfmt,...) const |
| Issue error message. | |
| virtual void | Execute (const char *method, const char *params, Int_t *error=0) |
| Execute method on this object with the given parameter string, e.g. | |
| virtual void | Execute (TMethod *method, TObjArray *params, Int_t *error=0) |
| Execute method on this object with parameters stored in the TObjArray. | |
| virtual void | ExecuteEvent (Int_t event, Int_t px, Int_t py) |
| Execute action corresponding to an event at (px,py). | |
| virtual void | Fatal (const char *method, const char *msgfmt,...) const |
| Issue fatal error message. | |
| virtual Option_t * | GetDrawOption () const |
| Get option used by the graphics system to draw this object. | |
| virtual const char * | GetIconName () const |
| Returns mime type name of object. | |
| virtual char * | GetObjectInfo (Int_t px, Int_t py) const |
| Returns string containing info about the object at position (px,py). | |
| virtual UInt_t | GetUniqueID () const |
| Return the unique object id. | |
| virtual Bool_t | HandleTimer (TTimer *timer) |
| Execute action in response of a timer timing out. | |
| Bool_t | HasInconsistentHash () const |
| Return true is the type of this object is known to have an inconsistent setup for Hash and RecursiveRemove (i.e. | |
| virtual void | Info (const char *method, const char *msgfmt,...) const |
| Issue info message. | |
| virtual Bool_t | InheritsFrom (const char *classname) const |
| Returns kTRUE if object inherits from class "classname". | |
| virtual Bool_t | InheritsFrom (const TClass *cl) const |
| Returns kTRUE if object inherits from TClass cl. | |
| virtual void | Inspect () const |
| Dump contents of this object in a graphics canvas. | |
| void | InvertBit (UInt_t f) |
| virtual Bool_t | IsEqual (const TObject *obj) const |
| Default equal comparison (objects are equal if they have the same address in memory). | |
| R__ALWAYS_INLINE Bool_t | IsOnHeap () const |
| R__ALWAYS_INLINE Bool_t | IsZombie () const |
| void | MayNotUse (const char *method) const |
| Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary). | |
| virtual Bool_t | Notify () |
| This method must be overridden to handle object notification. | |
| void | Obsolete (const char *method, const char *asOfVers, const char *removedFromVers) const |
| Use this method to declare a method obsolete. | |
| void | operator delete (void *ptr) |
| Operator delete. | |
| void | operator delete[] (void *ptr) |
| Operator delete []. | |
| void * | operator new (size_t sz) |
| void * | operator new (size_t sz, void *vp) |
| void * | operator new[] (size_t sz) |
| void * | operator new[] (size_t sz, void *vp) |
| TObject & | operator= (const TObject &rhs) |
| TObject assignment operator. | |
| virtual void | Pop () |
| Pop on object drawn in a pad to the top of the display list. | |
| virtual Int_t | Read (const char *name) |
| Read contents of object with specified name from the current directory. | |
| void | ResetBit (UInt_t f) |
| virtual void | SaveAs (const char *filename="", Option_t *option="") const |
| Save this object in the file specified by filename. | |
| virtual void | SavePrimitive (std::ostream &out, Option_t *option="") |
| Save a primitive as a C++ statement(s) on output stream "out". | |
| void | SetBit (UInt_t f) |
| void | SetBit (UInt_t f, Bool_t set) |
| Set or unset the user status bits as specified in f. | |
| virtual void | SetDrawOption (Option_t *option="") |
| Set drawing option for object. | |
| virtual void | SetUniqueID (UInt_t uid) |
| Set the unique object id. | |
| virtual void | SysError (const char *method, const char *msgfmt,...) const |
| Issue system error message. | |
| R__ALWAYS_INLINE Bool_t | TestBit (UInt_t f) const |
| Int_t | TestBits (UInt_t f) const |
| virtual void | UseCurrentStyle () |
| Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked. | |
| virtual void | Warning (const char *method, const char *msgfmt,...) const |
| Issue warning message. | |
Static Public Member Functions | |
| static TFileOpenHandle * | AsyncOpen (const char *name, Option_t *option="", const char *ftitle="", Int_t compress=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault, Int_t netopt=0) |
| Submit an asynchronous open request. | |
| static Bool_t | Cp (const char *src, const char *dst, Bool_t progressbar=kTRUE, UInt_t buffersize=1000000) |
| Allows to copy file from src to dst URL. | |
| static TFile *& | CurrentFile () |
| Return the current ROOT file if any. | |
| static EAsyncOpenStatus | GetAsyncOpenStatus (const char *name) |
| Get status of the async open request related to 'name'. | |
| static EAsyncOpenStatus | GetAsyncOpenStatus (TFileOpenHandle *handle) |
| Get status of the async open request related to 'handle'. | |
| static const char * | GetCacheFileDir () |
| Get the directory where to locally stage/cache remote files. | |
| static const TUrl * | GetEndpointUrl (const char *name) |
| Get final URL for file being opened asynchronously. | |
| static Long64_t | GetFileBytesRead () |
| Static function returning the total number of bytes read from all files. | |
| static Long64_t | GetFileBytesWritten () |
| Static function returning the total number of bytes written to all files. | |
| static Long64_t | GetFileCounter () |
| static Int_t | GetFileReadCalls () |
| Static function returning the total number of read calls from all files. | |
| static Bool_t | GetOnlyStaged () |
| Returns staged only flag. | |
| static UInt_t | GetOpenTimeout () |
| Returns open timeout (in ms). | |
| static Int_t | GetReadaheadSize () |
| Static function returning the readahead buffer size. | |
| static Bool_t | GetReadStreamerInfo () |
| If the streamerinfos are to be read at file opening. | |
| static EFileType | GetType (const char *name, Option_t *option="", TString *prefix=nullptr) |
| Resolve the file type as a function of the protocol field in 'name'. | |
| static void | IncrementFileCounter () |
| static TFile * | Open (const char *name, Option_t *option="", const char *ftitle="", Int_t compress=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault, Int_t netopt=0) |
| Create / open a file. | |
| static TFile * | Open (TFileOpenHandle *handle) |
| Waits for the completion of an asynchronous open request. | |
| static Bool_t | SetCacheFileDir (ROOT::Internal::TStringView cacheDir, Bool_t operateDisconnected=kTRUE, Bool_t forceCacheread=kFALSE) |
| static Bool_t | SetCacheFileDir (std::string_view cacheDir, Bool_t operateDisconnected=kTRUE, Bool_t forceCacheread=kFALSE) |
| Sets the directory where to locally stage/cache remote files. | |
| static void | SetFileBytesRead (Long64_t bytes=0) |
| static void | SetFileBytesWritten (Long64_t bytes=0) |
| static void | SetFileReadCalls (Int_t readcalls=0) |
| static Bool_t | SetOnlyStaged (Bool_t onlystaged) |
| Sets only staged flag. | |
| static UInt_t | SetOpenTimeout (UInt_t timeout) |
| Sets open timeout time (in ms). Returns previous timeout value. | |
| static void | SetReadaheadSize (Int_t bufsize=256000) |
| static void | SetReadStreamerInfo (Bool_t readinfo=kTRUE) |
| Specify if the streamerinfos must be read at file opening. | |
| static Bool_t | ShrinkCacheFileDir (Long64_t shrinkSize, Long_t cleanupInteval=0) |
| Try to shrink the cache to the desired size. | |
| Static Public Member Functions inherited from TDirectory | |
| static void | AddDirectory (Bool_t add=kTRUE) |
| Sets the flag controlling the automatic add objects like histograms, TGraph2D, etc in memory. | |
| static Bool_t | AddDirectoryStatus () |
| Static function: see TDirectory::AddDirectory for more comments. | |
| static Bool_t | Cd (const char *path) |
| Change current directory to "path". | |
| static std::atomic< TDirectory * > & | CurrentDirectory () |
| Return the current directory for the current thread. | |
| static void | DecodeNameCycle (const char *namecycle, char *name, Short_t &cycle, const size_t namesize=0) |
| Decode a namecycle "aap;2" into name "aap" and cycle "2". | |
| static void | EncodeNameCycle (char *buffer, const char *name, Short_t cycle) |
| Encode the name and cycle into buffer like: "aap;2". | |
| Static Public Member Functions inherited from TObject | |
| static Long_t | GetDtorOnly () |
| Return destructor only flag. | |
| static Bool_t | GetObjectStat () |
| Get status of object stat flag. | |
| static void | SetDtorOnly (void *obj) |
| Set destructor only flag. | |
| static void | SetObjectStat (Bool_t stat) |
| Turn on/off tracking of objects in the TObjectTable. | |
Protected Member Functions | |
| virtual Long64_t | DirCreateEntry (TDirectory *) |
| virtual Int_t | DirReadKeys (TDirectory *) |
| virtual void | DirWriteHeader (TDirectory *) |
| virtual void | DirWriteKeys (TDirectory *) |
| Bool_t | FlushWriteCache () |
| Flush the write cache if active. | |
| virtual EAsyncOpenStatus | GetAsyncOpenStatus () |
| virtual InfoListRet | GetStreamerInfoListImpl (bool lookupSICache) |
| See documentation of GetStreamerInfoList for more details. | |
| virtual void | Init (Bool_t create) |
| Initialize a TFile object. | |
| Int_t | MakeProjectParMake (const char *packname, const char *filename) |
| Create makefile at 'filemake' for PAR package 'pack'. | |
| Int_t | MakeProjectParProofInf (const char *packname, const char *proofinfdir) |
| Create BUILD.sh and SETUP.C under 'proofinf' for PAR package 'pack'. | |
| Int_t | ReadBufferViaCache (char *buf, Int_t len) |
| Read buffer via cache. | |
| virtual Int_t | SysClose (Int_t fd) |
| Interface to system close. All arguments like in POSIX close(). | |
| virtual Int_t | SysOpen (const char *pathname, Int_t flags, UInt_t mode) |
| Interface to system open. All arguments like in POSIX open(). | |
| virtual Int_t | SysRead (Int_t fd, void *buf, Int_t len) |
| Interface to system read. All arguments like in POSIX read(). | |
| virtual Long64_t | SysSeek (Int_t fd, Long64_t offset, Int_t whence) |
| Interface to system lseek. | |
| virtual Int_t | SysStat (Int_t fd, Long_t *id, Long64_t *size, Long_t *flags, Long_t *modtime) |
| Return file stat information. | |
| virtual Int_t | SysSync (Int_t fd) |
| Interface to system fsync. All arguments like in POSIX fsync(). | |
| virtual Int_t | SysWrite (Int_t fd, const void *buf, Int_t len) |
| Interface to system write. All arguments like in POSIX write(). | |
| Int_t | WriteBufferViaCache (const char *buf, Int_t len) |
| Write buffer via cache. | |
| Protected Member Functions inherited from TDirectoryFile | |
| void | BuildDirectoryFile (TFile *motherFile, TDirectory *motherDir) |
| Initialise directory to defaults. | |
| void | CleanTargets () |
| Clean the pointers to this object (gDirectory, TContext, etc.) | |
| void | InitDirectoryFile (TClass *cl=nullptr) |
| Initialize the key associated with this directory (and the related data members. | |
| Protected Member Functions inherited from TDirectory | |
| TDirectory (const TDirectory &directory)=delete | |
| void | BuildDirectory (TFile *motherFile, TDirectory *motherDir) |
| Initialise directory to defaults. | |
| Bool_t | cd1 (const char *path) |
| flag to add histograms, graphs,etc to the directory | |
| void | CleanTargets () |
| Clean the pointers to this object (gDirectory, TContext, etc.). | |
| void | FillFullPath (TString &buf) const |
| Recursive method to fill full path for directory. | |
| void | operator= (const TDirectory &)=delete |
| void | RegisterContext (TContext *ctxt) |
| Register a TContext pointing to this TDirectory object. | |
| void | RegisterGDirectory (std::atomic< TDirectory * > *) |
| Register a std::atomic<TDirectory*> that will soon be pointing to this TDirectory object. | |
| void | UnregisterContext (TContext *ctxt) |
| UnRegister a TContext pointing to this TDirectory object. | |
| Protected Member Functions inherited from TObject | |
| virtual void | DoError (int level, const char *location, const char *fmt, va_list va) const |
| Interface to ErrorHandler (protected). | |
| void | MakeZombie () |
Protected Attributes | |
| TArchiveFile * | fArchive {nullptr} |
| !Archive file from which we read this file | |
| Long64_t | fArchiveOffset {0} |
| !Offset at which file starts in archive | |
| TFileOpenHandle * | fAsyncHandle {nullptr} |
| !For proper automatic cleanup | |
| EAsyncOpenStatus | fAsyncOpenStatus {kAOSNotAsync} |
| !Status of an asynchronous open request | |
| Long64_t | fBEGIN {0} |
| First used byte in file. | |
| Long64_t | fBytesRead {0} |
| Number of bytes read from this file. | |
| Long64_t | fBytesReadExtra {0} |
| Number of extra bytes (overhead) read by the readahead buffer. | |
| Long64_t | fBytesWrite {0} |
| Number of bytes written to this file. | |
| TFileCacheRead * | fCacheRead {nullptr} |
| !Pointer to the read cache (if any) | |
| TMap * | fCacheReadMap {nullptr} |
| !Pointer to the read cache (if any) | |
| TFileCacheWrite * | fCacheWrite {nullptr} |
| !Pointer to the write cache (if any) | |
| TArrayC * | fClassIndex {nullptr} |
| !Index of TStreamerInfo classes written to this file | |
| Int_t | fCompress {0} |
| Compression level and algorithm. | |
| Int_t | fD {-1} |
| File descriptor. | |
| Long64_t | fEND {0} |
| Last used byte in file. | |
| TList * | fFree {nullptr} |
| Free segments linked list table. | |
| TList * | fInfoCache {nullptr} |
| !Cached list of the streamer infos in this file | |
| Bool_t | fInitDone {kFALSE} |
| !True if the file has been initialized | |
| Bool_t | fIsArchive {kFALSE} |
| !True if this is a pure archive file | |
| Bool_t | fIsPcmFile {kFALSE} |
| !True if the file is a ROOT pcm file. | |
| Bool_t | fIsRootFile {kTRUE} |
| !True is this is a ROOT file, raw file otherwise | |
| Bool_t | fMustFlush {kTRUE} |
| !True if the file buffers must be flushed | |
| Int_t | fNbytesFree {0} |
| Number of bytes for free segments structure. | |
| Int_t | fNbytesInfo {0} |
| Number of bytes for StreamerInfo record. | |
| Bool_t | fNoAnchorInName {kFALSE} |
| !True if we don't want to force the anchor to be appended to the file name | |
| Int_t | fNProcessIDs {0} |
| Number of TProcessID written to this file. | |
| Long64_t | fOffset {0} |
| !Seek offset cache | |
| TList * | fOpenPhases {nullptr} |
| !Time info about open phases | |
| TString | fOption |
| File options. | |
| TObjArray * | fProcessIDs {nullptr} |
| !Array of pointers to TProcessIDs | |
| Int_t | fReadCalls {0} |
| Number of read calls ( not counting the cache calls ) | |
| TString | fRealName |
| Effective real file name (not original url) | |
| Long64_t | fSeekFree {0} |
| Location on disk of free segments structure. | |
| Long64_t | fSeekInfo {0} |
| Location on disk of StreamerInfo record. | |
| Double_t | fSum2Buffer {0} |
| Sum of squares of buffer sizes of objects written so far. | |
| Double_t | fSumBuffer {0} |
| Sum of buffer sizes of objects written so far. | |
| Char_t | fUnits {0} |
| Number of bytes for file pointers. | |
| TUrl | fUrl |
| !URL of file | |
| Int_t | fVersion {0} |
| File format version. | |
| std::mutex | fWriteMutex |
| !Lock for writing baskets / keys into the file. | |
| Int_t | fWritten {0} |
| Number of objects written so far. | |
| Protected Attributes inherited from TDirectoryFile | |
| Int_t | fBufferSize {0} |
| Default buffer size to create new TKeys. | |
| TDatime | fDatimeC |
| Date and time when directory is created. | |
| TDatime | fDatimeM |
| Date and time of last modification. | |
| TFile * | fFile {nullptr} |
| Pointer to current file in memory. | |
| TList * | fKeys {nullptr} |
| Pointer to keys list in memory. | |
| Bool_t | fModified {kFALSE} |
| True if directory has been modified. | |
| Int_t | fNbytesKeys {0} |
| Number of bytes for the keys. | |
| Int_t | fNbytesName {0} |
| Number of bytes in TNamed at creation time. | |
| Long64_t | fSeekDir {0} |
| Location of directory on file. | |
| Long64_t | fSeekKeys {0} |
| Location of Keys record on file. | |
| Long64_t | fSeekParent {0} |
| Location of parent directory on file. | |
| Bool_t | fWritable {kFALSE} |
| True if directory is writable. | |
| Protected Attributes inherited from TDirectory | |
| TContext * | fContext {nullptr} |
| Buffer for GetPath() function. | |
| std::atomic< size_t > | fContextPeg |
| thread local gDirectory pointing to this object. | |
| std::vector< std::atomic< TDirectory * > * > | fGDirectories |
| Pointer to a list of TContext object pointing to this TDirectory. | |
| TList * | fList {nullptr} |
| TObject * | fMother {nullptr} |
| TString | fPathBuffer |
| std::atomic_flag | fSpinLock |
| Counter delaying the TDirectory destructor from finishing. | |
| TUUID | fUUID |
| Protected Attributes inherited from TNamed | |
| TString | fName |
| TString | fTitle |
Static Protected Attributes | |
| static TList * | fgAsyncOpenRequests = nullptr |
| static std::atomic< Long64_t > | fgBytesRead {0} |
| Number of bytes read by all TFile objects. | |
| static std::atomic< Long64_t > | fgBytesWrite {0} |
| Number of bytes written by all TFile objects. | |
| static TString | fgCacheFileDir |
| Directory where to locally stage files. | |
| static Bool_t | fgCacheFileDisconnected = kTRUE |
| Indicates, we trust in the files in the cache dir without stat on the cached file. | |
| static Bool_t | fgCacheFileForce = kFALSE |
| Indicates, to force all READ to CACHEREAD. | |
| static std::atomic< Long64_t > | fgFileCounter {0} |
| Counter for all opened files. | |
| static Bool_t | fgOnlyStaged = kFALSE |
| Before the file is opened, it is checked, that the file is staged, if not, the open fails. | |
| static UInt_t | fgOpenTimeout = TFile::kEternalTimeout |
| Timeout for open operations in ms - 0 corresponds to blocking i/o. | |
| static Int_t | fgReadaheadSize = 256000 |
| Readahead buffer size. | |
| static std::atomic< Int_t > | fgReadCalls {0} |
| Number of bytes read from all TFile objects. | |
| static Bool_t | fgReadInfo = kTRUE |
| if true (default) ReadStreamerInfo is called when opening a file | |
| static ROOT::Internal::RConcurrentHashColl | fgTsSIHashes |
| !TS Set of hashes built from read streamer infos | |
| Static Protected Attributes inherited from TDirectory | |
| static Bool_t | fgAddDirectory = kTRUE |
| MSVC doesn't support = ATOMIC_FLAG_INIT;. | |
Private Member Functions | |
| TFile (const TFile &)=delete | |
| void | operator= (const TFile &)=delete |
Static Private Member Functions | |
| static void | CpProgress (Long64_t bytesread, Long64_t size, TStopwatch &watch) |
| Print file copy progress. | |
| static TFile * | OpenFromCache (const char *name, Option_t *="", const char *ftitle="", Int_t compress=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault, Int_t netopt=0) |
| Open a file for reading through the file cache. | |
Friends | |
| class | TBasket |
| class | TDirectoryFile |
| class | TFilePrefetch |
Additional Inherited Members | |
| Protected Types inherited from TObject | |
| enum | { kOnlyPrepStep = BIT(3) } |
| Static Protected Member Functions inherited from TDirectory | |
| static Bool_t | Cd1 (const char *path) |
| Change current directory to "path". | |
#include <TFile.h>
| enum TFile::ECacheAction |
TTreeCache flushing semantics.
| Enumerator | |
|---|---|
| kDisconnect | |
| kDoNotDisconnect | |
| enum TFile::EFileType |
| enum TFile::EOpenTimeOut |
| enum TFile::ERelativeTo |
| enum TFile::EStatusBits |
|
privatedelete |
| TFile::TFile | ( | const char * | fname1, |
| Option_t * | option = "", |
||
| const char * | ftitle = "", |
||
| Int_t | compress = ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault |
||
| ) |
Opens or creates a local ROOT file.
| [in] | fname1 | The name of the file |
| [in] | option | Specifies the mode in which the file is opened |
| [in] | ftitle | The title of the file |
| [in] | compress | Specifies the compression algorithm and level |
It is recommended to specify fname1 as "<file>.root". The suffix ".root" will be used by object browsers to automatically identify the file as a ROOT file. If the constructor fails in any way IsZombie() will return true. Use IsOpen() to check if the file is (still) open. To open non-local files use the static TFile::Open() method, that will take care of opening the files using the correct remote file access plugin.
| Option | Description |
|---|---|
| NEW or CREATE | Create a new file and open it for writing, if the file already exists the file is not opened. |
| RECREATE | Create a new file, if the file already exists it will be overwritten. |
| UPDATE | Open an existing file for writing. If no file exists, it is created. |
| READ | Open an existing file for reading (default). |
| NET | Used by derived remote file access classes, not a user callable option. |
| WEB | Used by derived remote http access class, not a user callable option. |
If option = "" (default), READ is assumed. The file can be specified as a URL of the form:
file:///user/rdm/bla.root or file:/user/rdm/bla.root
The file can also be a member of an archive, in which case it is specified as:
multi.zip#file.root or multi.zip#0
which will open file.root which is a member of the file multi.zip archive or member 1 from the archive. For more on archive file support see the TArchiveFile class. TFile and its remote access plugins can also be used to open any file, i.e. also non ROOT files, using:
file.tar?filetype=raw
This is convenient because the many remote file access plugins allow easy access to/from the many different mass storage systems. The title of the file (ftitle) will be shown by the ROOT browsers. A ROOT file (like a Unix file system) may contain objects and directories. There are no restrictions for the number of levels of directories. A ROOT file is designed such that one can write in the file in pure sequential mode (case of BATCH jobs). In this case, the file may be read sequentially again without using the file index written at the end of the file. In case of a job crash, all the information on the file is therefore protected. A ROOT file can be used interactively. In this case, one has the possibility to delete existing objects and add new ones. When an object is deleted from the file, the freed space is added into the FREE linked list (fFree). The FREE list consists of a chain of consecutive free segments on the file. At the same time, the first 4 bytes of the freed record on the file are overwritten by GAPSIZE where GAPSIZE = -(Number of bytes occupied by the record). Option compress is used to specify the compression level and algorithm:
compress = 100 * algorithm + level
| Level | Explanation |
|---|---|
| 0 | objects written to this file will not be compressed. |
| 1 | minimal compression level but fast. |
| ... | .... |
| 9 | maximal compression level but slower and might use more memory. |
(For the currently supported algorithms, the maximum level is 9) If compress is negative it indicates the compression level is not set yet. The enumeration ROOT::RCompressionSetting::EAlgorithm associates each algorithm with a number. There is a utility function to help to set the value of compress. For example, ROOT::CompressionSettings(ROOT::kLZMA, 1) will build an integer which will set the compression to use the LZMA algorithm and compression level 1. These are defined in the header file Compression.h. Note that the compression settings may be changed at any time. The new compression settings will only apply to branches created or attached after the setting is changed and other objects written after the setting is changed. In case the file does not exist or is not a valid ROOT file, it is made a Zombie. One can detect this situation with a code like:
When opening the file, the system checks the validity of this directory. If something wrong is detected, an automatic Recovery is performed. In this case, the file is scanned sequentially reading all logical blocks and attempting to rebuild a correct directory (see TFile::Recover). One can disable the automatic recovery procedure when reading one or more files by setting the environment variable "TFile.Recover: 0" in the system.rootrc file.
A bit TFile::kReproducible can be enabled specifying the "reproducible" url option when creating the file:
Unlike regular TFiles, the content of such file has reproducible binary content when writing exactly same data. This achieved by writing pre-defined values for creation and modification date of TKey/TDirectory objects and null value for TUUID objects inside TFile. As drawback, TRef objects stored in such file cannot be read correctly.
In case the name of the file is not reproducible either (in case of creating temporary filenames) a value can be passed to the reproducible option to replace the name stored in the file.
|
static |
Submit an asynchronous open request.
See TFile::Open(const char *, ...) for an explanation of the arguments. A handler is returned which is to be passed to TFile::Open(TFileOpenHandle *) to get the real TFile instance once the file is open. This call never blocks and it is provided to allow parallel submission of file opening operations expected to take a long time. TFile::Open(TFileOpenHandle *) may block if the file is not yet ready. The sequence
TFile::Open(TFile::AsyncOpen(const char *, ...))
is equivalent to
TFile::Open(const char *, ...)
To be effective, the underlying TFile implementation must be able to support asynchronous open functionality. Currently, only TXNetFile supports it. If the functionality is not implemented, this call acts transparently by returning an handle with the arguments for the standard synchronous open run by TFile::Open(TFileOpenHandle *). The retuned handle will be adopted by TFile after opening completion in TFile::Open(TFileOpenHandle *); if opening is not finalized the handle must be deleted by the caller.
Close a file.
| [in] | option | If option == "R", all TProcessIDs referenced by this file are deleted. |
Calling TFile::Close("R") might be necessary in case one reads a long list of files having TRef, writing some of the referenced objects or TRef to a new file. If the TRef or referenced objects of the file being closed will not be referenced again, it is possible to minimize the size of the TProcessID data structures in memory by forcing a delete of the unused TProcessID.
Reimplemented from TDirectoryFile.
Reimplemented in TNetFile, TParallelMergingFile, TSQLFile, and TXMLFile.
|
staticprivate |
|
virtual |
|
virtual |
|
static |
Return the current ROOT file if any.
Note that if 'cd' has been called on a TDirectory that does not belong to a file, gFile will be unchanged and still points to the file of the previous current directory that was a file.
|
overridevirtual |
Delete object namecycle.
| [in] | namecycle | Encodes the name and cycle of the objects to delete |
Namecycle identifies an object in the top directory of the file namecycle has the format name;cycle.
Examples:
| name/cycle | Action |
|---|---|
| foo | delete object named foo in memory |
| foo;1 | delete cycle 1 of foo on file |
| foo;* | delete all cycles of foo on disk and also from memory |
| *;2 | delete all objects on file having the cycle 2 |
| *;* | delete all objects from memory and file |
| T*;* | delete all objects from memory and file and all subdirectories |
Reimplemented from TDirectoryFile.
|
inlineprotectedvirtual |
|
inlineprotectedvirtual |
|
inlineprotectedvirtual |
|
inlineprotectedvirtual |
Fill Graphics Structure and Paint.
Loop on all objects (memory or file) and all subdirectories.
Reimplemented from TDirectory.
|
overridevirtual |
Encode file output buffer.
The file output buffer contains only the FREE data record.
Reimplemented from TDirectoryFile.
|
virtual |
|
protected |
|
inline |
|
inlineprotectedvirtual |
|
static |
|
static |
| Int_t TFile::GetBestBuffer | ( | ) | const |
|
inlinevirtual |
|
inlinevirtual |
|
virtual |
|
virtual |
|
static |
| TFileCacheRead * TFile::GetCacheRead | ( | const TObject * | tree = nullptr | ) | const |
| TFileCacheWrite * TFile::GetCacheWrite | ( | ) | const |
| Float_t TFile::GetCompressionFactor | ( | ) |
|
inlinevirtual |
|
inlinevirtual |
|
static |
|
virtual |
|
static |
|
static |
|
static |
|
inlinevirtual |
|
inlinevirtual |
|
inlinevirtual |
Reimplemented in TDavixFile, and TNetXNGFile.
|
inlinevirtual |
|
static |
|
static |
|
inlineoverridevirtual |
|
static |
|
static |
If the streamerinfos are to be read at file opening.
See TFile::SetReadStreamerInfo for more documentation.
| Int_t TFile::GetRecordHeader | ( | char * | buf, |
| Long64_t | first, | ||
| Int_t | maxbytes, | ||
| Int_t & | nbytes, | ||
| Int_t & | objlen, | ||
| Int_t & | keylen | ||
| ) |
Read the logical record header starting at a certain postion.
| [in] | maxbytes | Bytes which are read into buf. |
| [out] | nbytes | Number of bytes in record if negative, this is a deleted record if 0, cannot read record, wrong value of argument first |
| [out] | objlen | Uncompressed object size |
| [out] | keylen | Length of logical record header |
The function reads nread bytes where nread is the minimum of maxbytes and the number of bytes before the end of file. The function returns nread. Note that the arguments objlen and keylen are returned only if maxbytes >=16
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Returns the current file size.
Returns -1 in case the file could not be stat'ed.
Reimplemented in TDavixFile, TWebFile, TNetXNGFile, TSQLFile, TXMLFile, and TMemFile.
| const TList * TFile::GetStreamerInfoCache | ( | ) |
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Read the list of TStreamerInfo objects written to this file.
The function returns a TList. It is the user's responsibility to delete the list created by this function.
Note the list, in addition to TStreamerInfo object, contains sometimes a TList named 'listOfRules' and containing the schema evolution rules related to the file's content.
Using the list, one can access additional information, e.g.:
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Resolve the file type as a function of the protocol field in 'name'.
If defined, the string 'prefix' is added when testing the locality of a 'name' with network-like structure (i.e. root://host//path); if the file is local, on return 'prefix' will contain the actual local path of the file.
Initialize a TFile object.
| [in] | create | Create a new file. |
TFile implementations providing asynchronous open functionality need to override this method to run the appropriate checks before calling this standard initialization part. See TXNetFile::Init for an example.
Reimplemented in TNetFile, TXNetFile, TNetXNGFile, TDavixFile, and TWebFile.
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List file contents.
Indentation is used to identify the file tree. Subdirectories are listed first, then objects in memory, then objects on the file.
Reimplemented from TDirectoryFile.
Mark unused bytes on the file.
The list of free segments is in the fFree linked list. When an object is deleted from the file, the freed space is added into the FREE linked list (fFree). The FREE list consists of a chain of consecutive free segments on the file. At the same time, the first 4 bytes of the freed record on the file are overwritten by GAPSIZE where GAPSIZE = -(Number of bytes occupied by the record).
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Generate source code necessary to access the objects stored in the file.
Generate code in directory dirname for all classes specified in argument classes If classes = "*" (default and currently the only supported value), the function generates an include file for each class in the StreamerInfo list for which a TClass object does not exist.
The code generated includes:
In the generated classes, map, multimap when the first template parameter is a class are replaced by a vector of pair. set and multiset when the tempalte parameter is a class are replaced by a vector. This is required since we do not have the code needed to order and/or compare the object of the classes. This is a quick explanation of the options available:
| Option | Details |
|---|---|
| new (default) | A new directory dirname is created. If dirname already exist, an error message is printed and the function returns. |
| recreate | If dirname does not exist, it is created (like in "new"). If dirname already exist, all existing files in dirname are deleted before creating the new files. |
| update | New classes are added to the existing directory. Existing classes with the same name are replaced by the new definition. If the directory dirname doest not exist, same effect as "new". |
| genreflex | Use genreflex rather than rootcint to generate the dictionary. |
| par | Create a PAR file with the minimal set of code needed to read the content of the ROOT file. The name of the PAR file is basename(dirname), with extension '.par' enforced; the PAR file will be created at dirname(dirname). |
If, in addition to one of the 3 above options, the option "+" is specified, the function will generate:
gSystem->load("demo/demo.so");
The following feature is not yet enabled: One can restrict the list of classes to be generated by using expressions like: classes = "Ali*" generate code only for classes starting with Ali classes = "myClass" generate code for class MyClass only.
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List the contents of a file sequentially.
For each logical record found, it prints:
Date/Time Record_Adress Logical_Record_Length ClassName CompressionFactor
Example of output
20010404/150437 At:64 N=150 TFile 20010404/150440 At:214 N=28326 TBasket CX = 1.13 20010404/150440 At:28540 N=29616 TBasket CX = 1.08 20010404/150440 At:58156 N=29640 TBasket CX = 1.08 20010404/150440 At:87796 N=29076 TBasket CX = 1.10 20010404/150440 At:116872 N=10151 TBasket CX = 3.15 20010404/150441 At:127023 N=28341 TBasket CX = 1.13 20010404/150441 At:155364 N=29594 TBasket CX = 1.08 20010404/150441 At:184958 N=29616 TBasket CX = 1.08 20010404/150441 At:214574 N=29075 TBasket CX = 1.10 20010404/150441 At:243649 N=9583 TBasket CX = 3.34 20010404/150442 At:253232 N=28324 TBasket CX = 1.13 20010404/150442 At:281556 N=29641 TBasket CX = 1.08 20010404/150442 At:311197 N=29633 TBasket CX = 1.08 20010404/150442 At:340830 N=29091 TBasket CX = 1.10 20010404/150442 At:369921 N=10341 TBasket CX = 3.09 20010404/150442 At:380262 N=509 TH1F CX = 1.93 20010404/150442 At:380771 N=1769 TH2F CX = 4.32 20010404/150442 At:382540 N=1849 TProfile CX = 1.65 20010404/150442 At:384389 N=18434 TNtuple CX = 4.51 20010404/150442 At:402823 N=307 KeysList 20010404/150443 At:403130 N=4548 StreamerInfo CX = 3.65 20010404/150443 At:407678 N=86 FreeSegments 20010404/150443 At:407764 N=1 END
If the parameter opt contains "forComp", the Date/Time is ommitted and the decompressed size is also printed.
Record_Adress Logical_Record_Length Key_Length Object_Record_Length ClassName CompressionFactor
If the parameter opt contains "extended", the name and title of the keys are added: 20200820/155031 At:100 N=180 TFile name: hsimple.root title: Demo ROOT file with histograms 220200820/155032 At:280 N=28880 TBasket CX = 1.11 name: random title: ntuple 220200820/155032 At:29160 N=29761 TBasket CX = 1.08 name: px title: ntuple 220200820/155032 At:58921 N=29725 TBasket CX = 1.08 name: py title: ntuple 220200820/155032 At:88646 N=29209 TBasket CX = 1.10 name: pz title: ntuple 220200820/155032 At:117855 N=10197 TBasket CX = 3.14 name: i title: ntuple ... 20200820/155032 At:405110 N=808 TNtuple CX = 3.53 name: ntuple title: Demo ntuple 20200820/155706 At:405918 N=307 KeysList name: hsimple.root title: Demo ROOT file with histograms 20200820/155032 At:406225 N=8556 StreamerInfo CX = 3.42 name: StreamerInfo title: Doubly linked list 20200820/155708 At:414781 N=86 FreeSegments name: hsimple.root title: Demo ROOT file with histograms 20200820/155708 At:414867 N=1 END
Note: The combined size of the classname, name and title is truncated to 476 characters (a little more for regular keys of small files)
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Create / open a file.
The type of the file can be either a TFile, TNetFile, TWebFile or any TFile derived class for which an plugin library handler has been registered with the plugin manager (for the plugin manager see the TPluginManager class). The returned type of TFile depends on the file name specified by 'url'. If 'url' is a '|'-separated list of file URLs, the 'URLs' are tried sequentially in the specified order until a successful open. If the file starts with "root:", "roots:" or "rootk:" a TNetFile object will be returned, with "http:" a TWebFile, with "file:" a local TFile, etc. (see the list of TFile plugin handlers in $ROOTSYS/etc/system.rootrc for regular expressions that will be checked) and as last a local file will be tried. Before opening a file via TNetFile a check is made to see if the URL specifies a local file. If that is the case the file will be opened via a normal TFile. To force the opening of a local file via a TNetFile use either TNetFile directly or specify as host "localhost". The netopt argument is only used by TNetFile. For the meaning of the options and other arguments see the constructors of the individual file classes. In case of error returns 0.
For TFile implementations supporting asynchronous file open, see TFile::AsyncOpen(...), it is possible to request a timeout with the option TIMEOUT=<secs>: the timeout must be specified in seconds and it will be internally checked with granularity of one millisec. For remote files there is the option: CACHEREAD opens an existing file for reading through the file cache. The file will be downloaded to the cache and opened from there. If the download fails, it will be opened remotely. The file will be downloaded to the directory specified by SetCacheFileDir().
The caller is responsible for deleting the pointer.
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Open a file for reading through the file cache.
The file will be downloaded to the cache and opened from there. If the download fails, it will be opened remotely. The file will be downloaded to the directory specified by SetCacheFileDir().
Paint all objects in the file.
Reimplemented from TDirectory.
Read a buffer from the file.
This is the basic low level read operation. Returns kTRUE in case of failure.
Reimplemented in TSQLFile, TXMLFile, TDCacheFile, TGFALFile, TDavixFile, TNetFile, TWebFile, TXNetFile, and TNetXNGFile.
Read a buffer from the file at the offset 'pos' in the file.
Returns kTRUE in case of failure. Compared to ReadBuffer(char*, Int_t), this routine does not change the cursor on the physical file representation (fD) if the data is in this TFile's cache.
Reimplemented in TSQLFile, TXMLFile, TDCacheFile, TGFALFile, TDavixFile, TNetFile, TWebFile, TXNetFile, and TNetXNGFile.
Reimplemented in TDavixFile, and TXNetFile.
Read the nbuf blocks described in arrays pos and len.
The value pos[i] is the seek position of block i of length len[i]. Note that for nbuf=1, this call is equivalent to TFile::ReafBuffer. This function is overloaded by TNetFile, TWebFile, etc. Returns kTRUE in case of failure.
Reimplemented in TDCacheFile, TDavixFile, TNetFile, TS3WebFile, TWebFile, TXNetFile, and TNetXNGFile.
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The TProcessID with number pidf is read from this file.
If the object is not already entered in the gROOT list, it is added.
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Read the list of StreamerInfo from this file.
The key with name holding the list of TStreamerInfo objects is read. The corresponding TClass objects are updated. Note that this function is not called if the static member fgReadInfo is false. (see TFile::SetReadStreamerInfo)
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Attempt to recover file if not correctly closed.
The function returns the number of keys that have been recovered. If no keys can be recovered, the file will be declared Zombie by the calling function. This function is automatically called when opening a file. If the file is open in read only mode, the file is not modified. If open in update mode and the function finds something to recover, a new directory header is written to the file. When opening the file gain no message from Recover will be reported. If keys have been recovered, the file is usable and you can safely read the corresponding objects. If the file is not usable (a zombie), you can test for this case with code like:
If the file has been recovered, the bit kRecovered is set in the TFile object in memory. You can test if the file has been recovered with
if (f.TestBit(TFile::kRecovered)) {... the file has been recovered}
When writing TTrees to a file, it is important to save the Tree header at regular intervals (see TTree::AutoSave). If a file containing a Tree is recovered, the last Tree header written to the file will be used. In this case all the entries in all the branches written before writing the header are valid entries. One can disable the automatic recovery procedure by setting
TFile.Recover 0
in the system.rootrc file.
Reopen a file with a different access mode.
For example, it is possible to change from READ to UPDATE or from NEW, CREATE, RECREATE, UPDATE to READ. Thus the mode argument can be either "READ" or "UPDATE". The method returns 0 in case the mode was successfully modified, 1 in case the mode did not change (was already as requested or wrong input arguments) and -1 in case of failure, in which case the file cannot be used anymore. The current directory (gFile) is changed to this file.
Reimplemented in TNetFile, TWebFile, TSQLFile, TXMLFile, and TNetXNGFile.
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Seek to a specific position in the file. Pos it either kBeg, kCur or kEnd.
Reimplemented in TDavixFile, TNetFile, TWebFile, TNetXNGFile, TSQLFile, and TXMLFile.
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Set a pointer to the read cache.
This relinquishes ownership of the previous cache, so if you do not already have a pointer to the previous cache (and there was a previous cache), you ought to retrieve (and delete it if needed) using:
TFileCacheRead *older = myfile->GetCacheRead();
The action specifies how to behave when detaching a cache from the the TFile. If set to (default) kDisconnect, the contents of the cache will be flushed when it is removed from the file, and it will disconnect the cache object from the file. In almost all cases, this is what you want. If you want to disconnect the cache temporarily from this tree and re-attach later to the same fil, you can set action to kDoNotDisconnect. This will allow things like prefetching to continue in the background while it is no longer the default cache for the TTree. Except for a few expert use cases, kDisconnect is likely the correct setting.
WARNING: if action=kDoNotDisconnect, you MUST delete the cache before TFile.
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Specify if the streamerinfos must be read at file opening.
If fgReadInfo is true (default) TFile::ReadStreamerInfo is called when opening the file. It may be interesting to set fgReadInfo to false to speedup the file opening time or in case libraries containing classes referenced by the file have not yet been loaded. if fgReadInfo is false, one can still read the StreamerInfo with myfile.ReadStreamerInfo();
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Return the size in bytes of the file header.
Reimplemented from TDirectoryFile.
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Return file stat information.
The interface and return value is identical to TSystem::GetPathInfo(). The function returns 0 in case of success and 1 if the file could not be stat'ed.
Reimplemented in TDCacheFile, TGFALFile, TNetFile, TXNetFile, TMemFile, TSQLFile, and TXMLFile.
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overridevirtual |
One can not save a const TDirectory object.
Reimplemented from TDirectoryFile.
Reimplemented in TSQLFile, TXMLFile, and TParallelMergingFile.
Write memory objects to this file.
Loop on all objects in memory (including subdirectories). A new key is created in the KEYS linked list for each object. The list of keys is then saved on the file (via WriteKeys) as a single data record. For values of opt see TObject::Write(). The directory header info is rewritten on the directory header record. The linked list of FREE segments is written. The file header is written (bytes 1->fBEGIN).
Reimplemented from TDirectoryFile.
Reimplemented in TSQLFile, TXMLFile, and TParallelMergingFile.
Write a buffer to the file.
This is the basic low level write operation. Returns kTRUE in case of failure.
Reimplemented in TSQLFile, TXMLFile, TDCacheFile, TGFALFile, TNetFile, TDavixFile, TXNetFile, and TNetXNGFile.
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Write the list of TStreamerInfo as a single object in this file The class Streamer description for all classes written to this file is saved.
See class TStreamerInfo.
Reimplemented in TParallelMergingFile, TSQLFile, and TXMLFile.
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!Index of TStreamerInfo classes written to this file
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Number of TProcessID written to this file.
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