A ROOT file is structured in Directories (like a file system).

Each Directory has a list of Keys (see TKeys) and a list of objects in memory. A Key is a small object that describes the type and location of a persistent object in a file. The persistent object may be a directory.

The structure of a file is shown in TFile::TFile

Definition at line 31 of file TDirectoryFile.h.

Public Types
enum	{ kCloseDirectory = BIT(7) }

Public Types inherited from TObject
enum	{ kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff }

enum	{ kSingleKey = BIT(0), kOverwrite = BIT(1), kWriteDelete = BIT(2) }

enum	EStatusBits { kCanDelete = BIT(0), kMustCleanup = BIT(3), kObjInCanvas = BIT(3), kIsReferenced = BIT(4), kHasUUID = BIT(5), kCannotPick = BIT(6), kNoContextMenu = BIT(8), kInvalidObject = BIT(13) }

Public Member Functions
	TDirectoryFile ()
	Default Constructor. More...

	TDirectoryFile (const char name, const char title, Option_t option="", TDirectory motherDir=0)
	Create a new TDirectoryFile. More...

virtual	~TDirectoryFile ()
	Destructor. More...

void	Add (TObject *obj, Bool_t replace=kFALSE)

virtual void	Append (TObject *obj, Bool_t replace=kFALSE)
	Append object to this directory. More...

Int_t	AppendKey (TKey *key)
	Insert key in the linked list of keys of this directory. More...

virtual void	Browse (TBrowser *b)
	Browse the content of the directory. More...

void	Build (TFile motherFile=0, TDirectory motherDir=0)
	Initialise directory to defaults. More...

virtual Bool_t	cd (const char *path=0)
	Change current directory to "this" directory. More...

virtual TObject *	CloneObject (const TObject *obj, Bool_t autoadd=kTRUE)
	Make a clone of an object using the Streamer facility. More...

virtual void	Close (Option_t *option="")
	Delete all objects from memory and directory structure itself. More...

virtual void	Copy (TObject &) const
	Copy this to obj. More...

virtual void	Delete (const char *namecycle="")
	Delete Objects or/and keys in a directory. More...

virtual void	FillBuffer (char *&buffer)
	Encode directory header into output buffer. More...

virtual TKey *	FindKey (const char *keyname) const
	Find key with name keyname in the current directory. More...

virtual TKey *	FindKeyAny (const char *keyname) const
	Find key with name keyname in the current directory or its subdirectories. More...

virtual TObject *	FindObjectAny (const char *name) const
	Find object by name in the list of memory objects of the current directory or its sub-directories. More...

virtual TObject *	FindObjectAnyFile (const char *name) const
	Scan the memory lists of all files for an object with name. More...

virtual TObject *	Get (const char *namecycle)
	Return pointer to object identified by namecycle. More...

virtual Int_t	GetBufferSize () const
	Return the buffer size to create new TKeys. More...

const TDatime &	GetCreationDate () const

virtual TDirectory *	GetDirectory (const char apath, Bool_t printError=false, const char funcname="GetDirectory")
	Find a directory named "apath". More...

virtual TFile *	GetFile () const

virtual TKey *	GetKey (const char *name, Short_t cycle=9999) const
	Return pointer to key with name,cycle. More...

virtual TList *	GetListOfKeys () const

const TDatime &	GetModificationDate () const

virtual Int_t	GetNbytesKeys () const

virtual Int_t	GetNkeys () const

template<class T >
void	GetObject (const char namecycle, T &ptr)

virtual void *	GetObjectChecked (const char namecycle, const char classname)
	See documentation of TDirectoryFile::GetObjectCheck(const char namecycle, const TClass cl) More...

virtual void *	GetObjectChecked (const char namecycle, const TClass cl)
	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. More...

virtual void *	GetObjectUnchecked (const char *namecycle)
	Return pointer to object identified by namecycle. More...

virtual Long64_t	GetSeekDir () const

virtual Long64_t	GetSeekKeys () const

virtual Long64_t	GetSeekParent () const

Bool_t	IsModified () const

Bool_t	IsWritable () const

virtual void	ls (Option_t *option="") const
	List Directory contents. More...

virtual TDirectory *	mkdir (const char name, const char title="")
	Create a sub-directory "a" or a hierarchy of sub-directories "a/b/c/...". More...

virtual TFile *	OpenFile (const char name, Option_t option="", const char *ftitle="", Int_t compress=1, Int_t netopt=0)
	Interface to TFile::Open. More...

virtual void	Purge (Short_t nkeep=1)
	Purge lowest key cycles in a directory. More...

virtual void	ReadAll (Option_t *option="")
	Read objects from a ROOT file directory into memory. More...

virtual Int_t	ReadKeys (Bool_t forceRead=kTRUE)
	Read the linked list of keys. More...

virtual Int_t	ReadTObject (TObject obj, const char keyname)
	Read object with keyname from the current directory. More...

virtual void	ResetAfterMerge (TFileMergeInfo *)
	Reset the TDirectory after its content has been merged into another Directory. More...

virtual void	rmdir (const char *name)
	Removes subdirectory from the directory. More...

virtual void	Save ()
	Save recursively all directory keys and headers. More...

virtual Int_t	SaveObjectAs (const TObject obj, const char filename="", Option_t *option="") const
	Save object in filename. More...

virtual void	SaveSelf (Bool_t force=kFALSE)
	Save Directory keys and header. More...

virtual void	SetBufferSize (Int_t bufsize)
	Set the default buffer size when creating new TKeys. More...

void	SetModified ()

void	SetSeekDir (Long64_t v)

virtual void	SetTRefAction (TObject ref, TObject parent)
	Find the action to be executed in the dictionary of the parent class and store the corresponding exec number into fBits. More...

void	SetWritable (Bool_t writable=kTRUE)
	Set the new value of fWritable recursively. More...

virtual Int_t	Sizeof () const
	Return the size in bytes of the directory header. More...

virtual Int_t	Write (const char *name=0, Int_t opt=0, Int_t bufsize=0)
	Write all objects in memory to disk. More...

virtual Int_t	Write (const char *name=0, Int_t opt=0, Int_t bufsize=0) const
	One can not save a const TDirectory object. More...

virtual void	WriteDirHeader ()
	Overwrite the Directory header record. More...

virtual void	WriteKeys ()
	Write Keys linked list on the file. More...

virtual Int_t	WriteObjectAny (const void obj, const char classname, const char name, Option_t option="", Int_t bufsize=0)
	Write object from pointer of class classname in this directory. More...

virtual Int_t	WriteObjectAny (const void obj, const TClass cl, const char name, Option_t option="", Int_t bufsize=0)
	Write object of class with dictionary cl in this directory. More...

virtual Int_t	WriteTObject (const TObject obj, const char name=0, Option_t *option="", Int_t bufsize=0)
	Write object obj to this directory. More...

Public Member Functions inherited from TDirectory
	TDirectory ()
	Directory default constructor. More...

	TDirectory (const char name, const char title, Option_t option="", TDirectory motherDir=0)
	Create a new Directory. More...

virtual	~TDirectory ()
	Destructor. More...

virtual void	Clear (Option_t *option="")
	Delete all objects from a Directory list. More...

virtual void	DeleteAll (Option_t *option="")
	Delete all objects from memory. More...

virtual void	Draw (Option_t *option="")
	Fill Graphics Structure and Paint. More...

virtual TObject *	FindObject (const char *name) const
	Find object by name in the list of memory objects. More...

virtual TObject *	FindObject (const TObject *obj) const
	Find object in the list of memory objects. More...

virtual TList *	GetList () const

virtual TObject *	GetMother () const

virtual TDirectory *	GetMotherDir () const

template<class T >
void	GetObject (const char namecycle, T &ptr)

virtual const char *	GetPath () const
	Returns the full path of the directory. More...

virtual const char *	GetPathStatic () const
	Returns the full path of the directory. More...

TUUID	GetUUID () const

virtual Bool_t	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). More...

virtual void	Paint (Option_t *option="")
	Paint all objects in the directory. More...

virtual void	Print (Option_t *option="") const
	Print all objects in the directory. More...

virtual void	pwd () const
	Print the path of the directory. More...

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove object from a Directory. More...

virtual TObject *	Remove (TObject *)
	Remove an object from the in-memory list. More...

virtual void	SetMother (TObject *mother)

virtual void	SetName (const char *newname)
	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. More...

template<class T >
Int_t	WriteObject (const T obj, const char name, Option_t *option="", Int_t bufsize=0)

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TString &name, const TString &title)

	TNamed (const TNamed &named)
	TNamed copy ctor. More...

virtual	~TNamed ()

virtual TObject *	Clone (const char *newname="") const
	Make a clone of an object using the Streamer facility. More...

virtual Int_t	Compare (const TObject *obj) const
	Compare two TNamed objects. More...

virtual const char *	GetName () const
	Returns name of object. More...

virtual const char *	GetTitle () const
	Returns title of object. More...

virtual ULong_t	Hash () const
	Return hash value for this object. More...

virtual Bool_t	IsSortable () const

TNamed &	operator= (const TNamed &rhs)
	TNamed assignment operator. More...

virtual void	SetNameTitle (const char name, const char title)
	Set all the TNamed parameters (name and title). More...

virtual void	SetTitle (const char *title="")
	Set the title of the TNamed. More...

Public Member Functions inherited from TObject
	TObject ()
	TObject constructor. More...

	TObject (const TObject &object)
	TObject copy ctor. More...

virtual	~TObject ()
	TObject destructor. More...

void	AbstractMethod (const char *method) const
	Use this method to implement an "abstract" method that you don't want to leave purely abstract. More...

virtual void	AppendPad (Option_t *option="")
	Append graphics object to current pad. More...

virtual const char *	ClassName () const
	Returns name of class to which the object belongs. More...

virtual Int_t	DistancetoPrimitive (Int_t px, Int_t py)
	Computes distance from point (px,py) to the object. More...

virtual void	DrawClass () const
	Draw class inheritance tree of the class to which this object belongs. More...

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current selected pad for instance with: `gROOT->SetSelectedPad(gPad)`. More...

virtual void	Dump () const
	Dump contents of object on stdout. More...

virtual void	Error (const char method, const char msgfmt,...) const
	Issue error message. More...

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. More...

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=0)
	Execute method on this object with parameters stored in the TObjArray. More...

virtual void	ExecuteEvent (Int_t event, Int_t px, Int_t py)
	Execute action corresponding to an event at (px,py). More...

virtual void	Fatal (const char method, const char msgfmt,...) const
	Issue fatal error message. More...

virtual Option_t *	GetDrawOption () const
	Get option used by the graphics system to draw this object. More...

virtual const char *	GetIconName () const
	Returns mime type name of object. More...

virtual char *	GetObjectInfo (Int_t px, Int_t py) const
	Returns string containing info about the object at position (px,py). More...

virtual Option_t *	GetOption () const

virtual UInt_t	GetUniqueID () const
	Return the unique object id. More...

virtual Bool_t	HandleTimer (TTimer *timer)
	Execute action in response of a timer timing out. More...

virtual void	Info (const char method, const char msgfmt,...) const
	Issue info message. More...

virtual Bool_t	InheritsFrom (const char *classname) const
	Returns kTRUE if object inherits from class "classname". More...

virtual Bool_t	InheritsFrom (const TClass *cl) const
	Returns kTRUE if object inherits from TClass cl. More...

virtual void	Inspect () const
	Dump contents of this object in a graphics canvas. More...

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). More...

Bool_t	IsOnHeap () const

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). More...

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification. More...

void	Obsolete (const char method, const char asOfVers, const char *removedFromVers) const
	Use this method to declare a method obsolete. More...

void	operator delete (void *ptr)
	Operator delete. More...

void	operator delete[] (void *ptr)
	Operator delete []. More...

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. More...

virtual void	Pop ()
	Pop on object drawn in a pad to the top of the display list. More...

virtual Int_t	Read (const char *name)
	Read contents of object with specified name from the current directory. More...

void	ResetBit (UInt_t f)

virtual void	SaveAs (const char filename="", Option_t option="") const
	Save this object in the file specified by filename. More...

virtual void	SavePrimitive (std::ostream &out, Option_t *option="")
	Save a primitive as a C++ statement(s) on output stream "out". More...

void	SetBit (UInt_t f, Bool_t set)
	Set or unset the user status bits as specified in f. More...

void	SetBit (UInt_t f)

virtual void	SetDrawOption (Option_t *option="")
	Set drawing option for object. More...

virtual void	SetUniqueID (UInt_t uid)
	Set the unique object id. More...

virtual void	SysError (const char method, const char msgfmt,...) const
	Issue system error message. More...

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. More...

virtual void	Warning (const char method, const char msgfmt,...) const
	Issue warning message. More...

Protected Member Functions
virtual void	CleanTargets ()
	Clean the pointers to this object (gDirectory, TContext, etc.) More...

void	Init (TClass *cl=0)
	Initialize the key associated with this directory (and the related data members. More...

Protected Member Functions inherited from TDirectory
	TDirectory (const TDirectory &directory)
	Copy constructor. More...

Bool_t	cd1 (const char *path)
	flag to add histograms, graphs,etc to the directory More...

void	FillFullPath (TString &buf) const
	Recursive method to fill full path for directory. More...

void	operator= (const TDirectory &)

void	RegisterContext (TContext *ctxt)
	Register a TContext pointing to this TDirectory object. More...

void	UnregisterContext (TContext *ctxt)
	UnRegister a TContext pointing to this TDirectory object. More...

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). More...

void	MakeZombie ()

Protected Attributes
Int_t	fBufferSize
	Default buffer size to create new TKeys. More...

TDatime	fDatimeC
	Date and time when directory is created. More...

TDatime	fDatimeM
	Date and time of last modification. More...

TFile *	fFile
	Pointer to current file in memory. More...

TList *	fKeys
	Pointer to keys list in memory. More...

Bool_t	fModified
	True if directory has been modified. More...

Int_t	fNbytesKeys
	Number of bytes for the keys. More...

Int_t	fNbytesName
	Number of bytes in TNamed at creation time. More...

Long64_t	fSeekDir
	Location of directory on file. More...

Long64_t	fSeekKeys
	Location of Keys record on file. More...

Long64_t	fSeekParent
	Location of parent directory on file. More...

Bool_t	fWritable
	True if directory is writable. More...

Protected Attributes inherited from TDirectory
TContext *	fContext
	Buffer for GetPath() function. More...

TList *	fList

TObject *	fMother

TString	fPathBuffer

TUUID	fUUID

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

Private Member Functions
	TDirectoryFile (const TDirectoryFile &directory)
	Copy constructor. More...

void	operator= (const TDirectoryFile &)

Additional Inherited Members
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. More...

static Bool_t	AddDirectoryStatus ()
	Static function: see TDirectory::AddDirectory for more comments. More...

static Bool_t	Cd (const char *path)
	Change current directory to "path". More...

static TDirectory *&	CurrentDirectory ()
	Return the current directory for the current thread. More...

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". More...

static void	EncodeNameCycle (char buffer, const char name, Short_t cycle)
	Encode the name and cycle into buffer like: "aap;2". More...

Static Public Member Functions inherited from TObject
static Long_t	GetDtorOnly ()
	Return destructor only flag. More...

static Bool_t	GetObjectStat ()
	Get status of object stat flag. More...

static void	SetDtorOnly (void *obj)
	Set destructor only flag. More...

static void	SetObjectStat (Bool_t stat)
	Turn on/off tracking of objects in the TObjectTable. More...

Static Protected Member Functions inherited from TDirectory
static Bool_t	Cd1 (const char *path)
	Change current directory to "path". More...

Static Protected Attributes inherited from TDirectory
static Bool_t	fgAddDirectory = kTRUE
	Pointer to a list of TContext object pointing to this TDirectory. More...

#include <TDirectoryFile.h>

Inheritance diagram for TDirectoryFile:

[legend]

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Enumerator
kCloseDirectory

Definition at line 56 of file TDirectoryFile.h.

Constructor & Destructor Documentation

◆ TDirectoryFile() [1/3]

TDirectoryFile::TDirectoryFile ( const TDirectoryFile & directory )

private

Copy constructor.

Definition at line 169 of file TDirectoryFile.cxx.

◆ TDirectoryFile() [2/3]

TDirectoryFile::TDirectoryFile ( )

Default Constructor.

Definition at line 61 of file TDirectoryFile.cxx.

◆ TDirectoryFile() [3/3]

TDirectoryFile::TDirectoryFile	(	const char *	name,
		const char *	title,
		Option_t *	classname = `""`,
		TDirectory *	initMotherDir = `0`
	)

Create a new TDirectoryFile.

A new directory with a name and a title is created in the current directory. The directory header information is immediatly saved on the file A new key is added in the parent directory. When this constructor is called from a class directly derived from TDirectoryFile, the third argument, classname, MUST be specified. In this case, classname must be the name of the derived class.

Note that the directory name cannot contain slashes.

Definition at line 80 of file TDirectoryFile.cxx.

◆ ~TDirectoryFile()

TDirectoryFile::~TDirectoryFile ( )

virtual

Destructor.

Definition at line 180 of file TDirectoryFile.cxx.

Member Function Documentation

◆ Add()

void TDirectoryFile::Add	(	TObject *	obj,
		Bool_t	replace = `kFALSE`
	)

inlinevirtual

Reimplemented from TDirectory.

Definition at line 62 of file TDirectoryFile.h.

◆ Append()

void TDirectoryFile::Append	(	TObject *	obj,
		Bool_t	replace = `kFALSE`
	)

virtual

Append object to this directory.

If replace is true: remove any existing objects with the same same (if the name is not ""

Reimplemented from TDirectory.

Definition at line 212 of file TDirectoryFile.cxx.

◆ AppendKey()

Int_t TDirectoryFile::AppendKey ( TKey * key )

virtual

Insert key in the linked list of keys of this directory.

Reimplemented from TDirectory.

Definition at line 228 of file TDirectoryFile.cxx.

◆ Browse()

void TDirectoryFile::Browse ( TBrowser * b )

virtual

Browse the content of the directory.

Reimplemented from TDirectory.

Definition at line 258 of file TDirectoryFile.cxx.

◆ Build()

void TDirectoryFile::Build	(	TFile *	motherFile = `0`,
		TDirectory *	motherDir = `0`
	)

virtual

Initialise directory to defaults.

Reimplemented from TDirectory.

Definition at line 303 of file TDirectoryFile.cxx.

◆ cd()

Bool_t TDirectoryFile::cd ( const char * path = 0 )

virtual

Change current directory to "this" directory.

Using path one can change the current directory to "path". The absolute path syntax is:

file.root:/dir1/dir2

where file.root is the file and /dir1/dir2 the desired subdirectory in the file. Relative syntax is relative to "this" directory. E.g: ../aa. Returns kTRUE in case of success.

Reimplemented from TDirectory.

Definition at line 337 of file TDirectoryFile.cxx.

◆ CleanTargets()

void TDirectoryFile::CleanTargets ( )

protectedvirtual

Clean the pointers to this object (gDirectory, TContext, etc.)

Reimplemented from TDirectory.

Definition at line 347 of file TDirectoryFile.cxx.

◆ CloneObject()

TObject * TDirectoryFile::CloneObject	(	const TObject *	obj,
		Bool_t	autoadd = `kTRUE`
	)

virtual

Make a clone of an object using the Streamer facility.

If the object derives from TNamed, this function is called by TNamed::Clone. TNamed::Clone uses the optional argument newname to set a new name to the newly created object.

If autoadd is true and if the object class has a DirectoryAutoAdd function, it will be called at the end of the function with the parameter gDirectory. This usually means that the object will be appended to the current ROOT directory.

Reimplemented from TDirectory.

Definition at line 370 of file TDirectoryFile.cxx.

◆ Close()

void TDirectoryFile::Close ( Option_t * option = "" )

virtual

Delete all objects from memory and directory structure itself.

Reimplemented from TDirectory.

Reimplemented in TSQLFile, TFile, TNetFile, TXMLFile, and TParallelMergingFile.

Definition at line 536 of file TDirectoryFile.cxx.

◆ Copy()

virtual void TDirectoryFile::Copy ( TObject & named ) const

inlinevirtual

Copy this to obj.

Reimplemented from TDirectory.

Reimplemented in TFile.

Definition at line 68 of file TDirectoryFile.h.

◆ Delete()

void TDirectoryFile::Delete ( const char * namecycle = "" )

virtual

Delete Objects or/and keys in a directory.

Properties of the namecycle string:

namecycle has the format name;cycle
namecycle = "" is same as namecycle ="T*"
name = * means all
cycle = * means all cycles (memory and keys)
cycle = "" or cycle = 9999 ==> apply to a memory object When name=* use T* to delete subdirectories also

To delete one directory, you must specify the directory cycle, eg. file.Delete("dir1;1");

Examples:

Pattern	Description
foo	delete object named foo in memory
foo*	delete all objects with a name starting with foo
foo;1	delete cycle 1 of foo on file
foo;*	delete all cycles of foo on file 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

WARNING

If the key to be deleted contains special characters ("+","^","?", etc that have a special meaning for the regular expression parser (see TRegexp) then you must specify 2 backslash characters to escape the regular expression. For example, if the key to be deleted is namecycle = "C++", you must call

mydir.Delete("C\\+\\+"));

Reimplemented from TDirectory.

Reimplemented in TFile.

Definition at line 604 of file TDirectoryFile.cxx.

◆ FillBuffer()

void TDirectoryFile::FillBuffer ( char *& buffer )

virtual

Encode directory header into output buffer.

Reimplemented from TNamed.

Reimplemented in TSQLFile, TFile, and TXMLFile.

Definition at line 708 of file TDirectoryFile.cxx.

◆ FindKey()

TKey * TDirectoryFile::FindKey ( const char * keyname ) const

virtual

Find key with name keyname in the current directory.

Reimplemented from TDirectory.

Definition at line 743 of file TDirectoryFile.cxx.

◆ FindKeyAny()

TKey * TDirectoryFile::FindKeyAny ( const char * keyname ) const

virtual

Find key with name keyname in the current directory or its subdirectories.

NOTE: that If a key is found, the directory containing the key becomes the current directory

Reimplemented from TDirectory.

Definition at line 759 of file TDirectoryFile.cxx.

◆ FindObjectAny()

TObject * TDirectoryFile::FindObjectAny ( const char * aname ) const

virtual

Find object by name in the list of memory objects of the current directory or its sub-directories.

After this call the current directory is not changed. To automatically set the current directory where the object is found, use FindKeyAny(aname)->ReadObj().

Reimplemented from TDirectory.

Definition at line 799 of file TDirectoryFile.cxx.

◆ FindObjectAnyFile()

TObject * TDirectoryFile::FindObjectAnyFile ( const char * name ) const

virtual

Scan the memory lists of all files for an object with name.

Reimplemented from TDirectory.

Definition at line 428 of file TDirectoryFile.cxx.

◆ Get()

TObject * TDirectoryFile::Get ( const char * namecycle )

virtual

Return pointer to object identified by namecycle.

Properties:

namecycle has the format name;cycle
name = * is illegal, cycle = * is illegal
cycle = "" or cycle = 9999 ==> apply to a memory object

Examples:

Pattern	Explanation
foo	get object named foo in memory if object is not in memory, try with highest cycle from file
foo;1	get cycle 1 of foo on file

The retrieved object should in principle derive from TObject. If not, the function TDirectoryFile::GetObject should be called. However, this function will still work for a non-TObject, provided that the calling application cast the return type to the correct type (which is the actual type of the object).

The GetObjectMethod

The method GetObject offers better protection and avoids the need for any cast:

MyClass *obj;
directory->GetObject("some object",obj);
if (obj) { ... the object exist and inherits from MyClass ... }

Very important note about inheritance

In case the class of this object derives from TObject but not as a first inheritance, one must use dynamic_cast<>().

Example 1 - Normal case:

class MyClass : public TObject, public AnotherClass

then on return, one can adopt a C style cast:

auto objPtr = (MyClass*)directory->Get("some object of MyClass");

Example 2 - Special case:

class MyClass : public AnotherClass, public TObject

then on return, one must do:

auto objPtr = dynamic_cast<MyClass*>(directory->Get("some object of MyClass"));

Of course, dynamic_cast<> can also be used in the example 1.

Reimplemented from TDirectory.

Definition at line 887 of file TDirectoryFile.cxx.

◆ GetBufferSize()

Int_t TDirectoryFile::GetBufferSize ( ) const

virtual

Return the buffer size to create new TKeys.

If the stored fBufferSize is null, the value returned is the average buffer size of objects in the file so far.

Reimplemented from TDirectory.

Definition at line 1061 of file TDirectoryFile.cxx.

◆ GetCreationDate()

const TDatime& TDirectoryFile::GetCreationDate ( ) const

inline

Definition at line 86 of file TDirectoryFile.h.

◆ GetDirectory()

TDirectory * TDirectoryFile::GetDirectory	(	const char *	apath,
		Bool_t	printError = `false`,
		const char *	funcname = `"GetDirectory"`
	)

virtual

Find a directory named "apath".

It apath is null or empty, returns "this" directory. Otherwise use the name "apath" to find a directory. The absolute path syntax is:

file.root:/dir1/dir2

where file.root is the file and /dir1/dir2 the desired subdirectory in the file. Relative syntax is relative to "this" directory. E.g: ../aa. Returns 0 in case path does not exist. If printError is true, use Error with 'funcname' to issue an error message.

Reimplemented from TDirectory.

Definition at line 457 of file TDirectoryFile.cxx.

◆ GetFile()

virtual TFile* TDirectoryFile::GetFile ( ) const

inlinevirtual

Reimplemented from TDirectory.

Definition at line 87 of file TDirectoryFile.h.

◆ GetKey()

TKey * TDirectoryFile::GetKey	(	const char *	name,
		Short_t	cycle = `9999`
	)		const

virtual

Return pointer to key with name,cycle.

if cycle = 9999 returns highest cycle

Reimplemented from TDirectory.

Definition at line 1073 of file TDirectoryFile.cxx.

◆ GetListOfKeys()

virtual TList* TDirectoryFile::GetListOfKeys ( ) const

inlinevirtual

Reimplemented from TDirectory.

Definition at line 89 of file TDirectoryFile.h.

◆ GetModificationDate()

const TDatime& TDirectoryFile::GetModificationDate ( ) const

inline

Definition at line 90 of file TDirectoryFile.h.

◆ GetNbytesKeys()

virtual Int_t TDirectoryFile::GetNbytesKeys ( ) const

inlinevirtual

Reimplemented from TDirectory.

Definition at line 91 of file TDirectoryFile.h.

◆ GetNkeys()

virtual Int_t TDirectoryFile::GetNkeys ( ) const

inlinevirtual

Reimplemented from TDirectory.

Definition at line 92 of file TDirectoryFile.h.

◆ GetObject()

template<class T >

void TDirectoryFile::GetObject	(	const char *	namecycle,
		T *&	ptr
	)

inline

Definition at line 78 of file TDirectoryFile.h.

◆ GetObjectChecked() [1/2]

void * TDirectoryFile::GetObjectChecked	(	const char *	namecycle,
		const char *	classname
	)

virtual

See documentation of TDirectoryFile::GetObjectCheck(const char *namecycle, const TClass *cl)

Reimplemented from TDirectory.

Definition at line 964 of file TDirectoryFile.cxx.

◆ GetObjectChecked() [2/2]

void * TDirectoryFile::GetObjectChecked	(	const char *	namecycle,
		const TClass *	expectedClass
	)

virtual

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.

namecycle has the format name;cycle
name = * is illegal, cycle = * is illegal
cycle = "" or cycle = 9999 ==> apply to a memory object

Very important note

The calling application must cast the returned pointer to the type described by the 2 arguments (i.e. cl):

auto objPtr = (MyClass*)directory->GetObjectChecked("some object of MyClass","MyClass"));

Note: We recommend using the method TDirectoryFile::GetObject:

MyClass *obj = nullptr;
directory->GetObject("some object inheriting from MyClass",obj);
if (obj) { ... we found what we are looking for ... }

Reimplemented from TDirectory.

Definition at line 992 of file TDirectoryFile.cxx.

◆ GetObjectUnchecked()

void * TDirectoryFile::GetObjectUnchecked ( const char * namecycle )

virtual

Return pointer to object identified by namecycle.

The returned object may or may not derive from TObject.

namecycle has the format name;cycle
name = * is illegal, cycle = * is illegal
cycle = "" or cycle = 9999 ==> apply to a memory object

Very important note

The calling application must cast the returned object to the final type, e.g.

auto objPtr = (MyClass*)directory->GetObject("some object of MyClass");

Reimplemented from TDirectory.

Definition at line 956 of file TDirectoryFile.cxx.

◆ GetSeekDir()

virtual Long64_t TDirectoryFile::GetSeekDir ( ) const

inlinevirtual

Reimplemented from TDirectory.

Definition at line 93 of file TDirectoryFile.h.

◆ GetSeekKeys()

virtual Long64_t TDirectoryFile::GetSeekKeys ( ) const

inlinevirtual

Reimplemented from TDirectory.

Definition at line 95 of file TDirectoryFile.h.

◆ GetSeekParent()

virtual Long64_t TDirectoryFile::GetSeekParent ( ) const

inlinevirtual

Reimplemented from TDirectory.

Definition at line 94 of file TDirectoryFile.h.

◆ Init()

void TDirectoryFile::Init ( TClass * cl = 0 )

protected

Initialize the key associated with this directory (and the related data members.

Definition at line 139 of file TDirectoryFile.cxx.

◆ IsModified()

Bool_t TDirectoryFile::IsModified ( ) const

inlinevirtual

Reimplemented from TDirectory.

Definition at line 96 of file TDirectoryFile.h.

◆ IsWritable()

Bool_t TDirectoryFile::IsWritable ( ) const

inlinevirtual

Reimplemented from TDirectory.

Definition at line 97 of file TDirectoryFile.h.

◆ ls()

void TDirectoryFile::ls ( Option_t * option = "" ) const

virtual

List Directory contents.

Indentation is used to identify the directory tree Subdirectories are listed first, then objects in memory, then objects on the file

The option can has the following format: [-d |-m][<regexp>] Options:

-d: only list objects in the file
-m: only list objects in memory The <regexp> will be used to match the name of the objects. By default memory and disk objects are listed.

Reimplemented from TDirectory.

Reimplemented in TFile.

Definition at line 1102 of file TDirectoryFile.cxx.

◆ mkdir()

TDirectory * TDirectoryFile::mkdir	(	const char *	name,
		const char *	title = `""`
	)

virtual

Create a sub-directory "a" or a hierarchy of sub-directories "a/b/c/...".

Returns 0 in case of error or if a sub-directory (hierarchy) with the requested name already exists. Returns a pointer to the created sub-directory or to the top sub-directory of the hierarchy (in the above example, the returned TDirectory * always points to "a").

Reimplemented from TDirectory.

Definition at line 1167 of file TDirectoryFile.cxx.

◆ OpenFile()

TFile * TDirectoryFile::OpenFile	(	const char *	name,
		Option_t *	option = `""`,
		const char *	ftitle = `""`,
		Int_t	compress = `1`,
		Int_t	netopt = `0`
	)

virtual

Interface to TFile::Open.

Reimplemented from TDirectory.

Definition at line 1151 of file TDirectoryFile.cxx.

◆ operator=()

void TDirectoryFile::operator= ( const TDirectoryFile & )

private

◆ Purge()

void TDirectoryFile::Purge ( Short_t nkeep = 1 )

virtual

Purge lowest key cycles in a directory.

By default, only the highest cycle of a key is kept. Keys for which the "KEEP" flag has been set are not removed. See TKey::Keep().

Reimplemented from TDirectory.

Definition at line 1206 of file TDirectoryFile.cxx.

◆ ReadAll()

void TDirectoryFile::ReadAll ( Option_t * opt = "" )

virtual

Read objects from a ROOT file directory into memory.

If an object is already in memory, the memory copy is deleted and the object is again read from the file. If opt=="dirs", only subdirectories will be read If opt=="dirs*" complete directory tree will be read

Reimplemented from TDirectory.

Definition at line 1242 of file TDirectoryFile.cxx.

◆ ReadKeys()

Int_t TDirectoryFile::ReadKeys ( Bool_t forceRead = kTRUE )

virtual

Read the linked list of keys.

Every directory has a linked list (fKeys). This linked list has been written on the file via WriteKeys as a single data record.

It is interesting to call this function in the following situation. Assume another process1 is connecting this directory in Update mode

Process1 is adding/updating objects in this directory
You want to see the latest status from process1. Example Process1:
obj1.Write();
obj2.Write();
gDirectory->SaveSelf();

Example Process2:

gDirectory->ReadKeys();

obj1->Draw();

This is an efficient way (without opening/closing files) to view the latest updates of a file being modified by another process as it is typically the case in a data acquisition system.

Reimplemented from TDirectory.

Definition at line 1295 of file TDirectoryFile.cxx.

◆ ReadTObject()

Int_t TDirectoryFile::ReadTObject	(	TObject *	obj,
		const char *	keyname
	)

virtual

Read object with keyname from the current directory.

Read contents of object with specified name from the current directory. First the key with keyname is searched in the current directory, next the key buffer is deserialized into the object. The object must have been created before via the default constructor. See TObject::Write().

Reimplemented from TDirectory.

Definition at line 1381 of file TDirectoryFile.cxx.

◆ ResetAfterMerge()

void TDirectoryFile::ResetAfterMerge ( TFileMergeInfo * info )

virtual

Reset the TDirectory after its content has been merged into another Directory.

This returns the TDirectoryFile object back to its state before any data has been written to the file. The object in the in-memory list are assumed to also have been reset.

Reimplemented in TMemFile.

Definition at line 1403 of file TDirectoryFile.cxx.

◆ rmdir()

void TDirectoryFile::rmdir ( const char * name )

virtual

Removes subdirectory from the directory.

When diredctory is deleted, all keys in all subdirectories will be read first and deleted from file (if exists) Equivalent call is Delete("name;*");

Reimplemented from TDirectory.

Definition at line 1449 of file TDirectoryFile.cxx.

◆ Save()

void TDirectoryFile::Save ( )

virtual

Save recursively all directory keys and headers.

Reimplemented from TDirectory.

Definition at line 1461 of file TDirectoryFile.cxx.

◆ SaveObjectAs()

Int_t TDirectoryFile::SaveObjectAs	(	const TObject *	obj,
		const char *	filename = `""`,
		Option_t *	option = `""`
	)		const

virtual

Save object in filename.

If filename is 0 or "", a file with "objectname.root" is created. The name of the key is the object name. If the operation is successful, it returns the number of bytes written to the file otherwise it returns 0. By default a message is printed. Use option "q" to not print the message. If filename contains ".json" extension, JSON representation of the object will be created and saved in the text file. Such file can be used in JavaScript ROOT (https://root.cern.ch/js/) to display object in web browser When creating JSON file, option string may contain compression level from 0 to 3 (default 0)

Reimplemented from TDirectory.

Definition at line 1493 of file TDirectoryFile.cxx.

◆ SaveSelf()

void TDirectoryFile::SaveSelf ( Bool_t force = kFALSE )

virtual

Save Directory keys and header.

If the directory has been modified (fModified set), write the keys and the directory header. This function assumes the cd is correctly set.

It is recommended to use this function in the following situation: Assume a process1 using a directory in Update mode

New objects or modified objects have been written to the directory.
You do not want to close the file.
You want your changes be visible from another process2 already connected to this directory in read mode.
Call this function.
In process2, use TDirectoryFile::ReadKeys to refresh the directory.

Reimplemented from TDirectory.

Definition at line 1534 of file TDirectoryFile.cxx.

◆ SetBufferSize()

void TDirectoryFile::SetBufferSize ( Int_t bufsize )

virtual

Set the default buffer size when creating new TKeys.

◆ SetModified()

void TDirectoryFile::SetModified ( )

inlinevirtual

Reimplemented from TDirectory.

Definition at line 113 of file TDirectoryFile.h.

◆ SetSeekDir()

void TDirectoryFile::SetSeekDir ( Long64_t v )

inlinevirtual

Reimplemented from TDirectory.

Definition at line 114 of file TDirectoryFile.h.

◆ SetTRefAction()

void TDirectoryFile::SetTRefAction	(	TObject *	ref,
		TObject *	parent
	)

virtual

Find the action to be executed in the dictionary of the parent class and store the corresponding exec number into fBits.

This function searches a data member in the class of parent with an offset corresponding to this. If a comment "TEXEC:" is found in the comment field of the data member, the function stores the exec identifier of the exec statement following this keyword.

Reimplemented from TDirectory.

Definition at line 1570 of file TDirectoryFile.cxx.

◆ SetWritable()

void TDirectoryFile::SetWritable ( Bool_t writable = kTRUE )

virtual

Set the new value of fWritable recursively.

Reimplemented from TDirectory.

Definition at line 1589 of file TDirectoryFile.cxx.

◆ Sizeof()

Int_t TDirectoryFile::Sizeof ( ) const

virtual

Return the size in bytes of the directory header.

Reimplemented from TDirectory.

Reimplemented in TFile, TSQLFile, and TXMLFile.

Definition at line 1612 of file TDirectoryFile.cxx.

◆ Write() [1/2]

Int_t TDirectoryFile::Write	(	const char *	name = `0`,
		Int_t	opt = `0`,
		Int_t	bufsize = `0`
	)

virtual

Write all objects in memory to disk.

Loop on all objects in memory (including subdirectories). A new key is created in the keys linked list for each object. For allowed options see TObject::Write(). The directory header info is rewritten on the directory header record.

Reimplemented from TDirectory.

Reimplemented in TFile, TSQLFile, ROOT::Experimental::TBufferMergerFile, TXMLFile, and TParallelMergingFile.

Definition at line 1742 of file TDirectoryFile.cxx.

◆ Write() [2/2]

Int_t TDirectoryFile::Write	(	const char *	name = `0`,
		Int_t	opt = `0`,
		Int_t	bufsize = `0`
	)		const

virtual

One can not save a const TDirectory object.

Reimplemented from TDirectory.

Reimplemented in TFile, TSQLFile, TXMLFile, and TParallelMergingFile.

Definition at line 1762 of file TDirectoryFile.cxx.

◆ WriteDirHeader()

void TDirectoryFile::WriteDirHeader ( )

virtual

Overwrite the Directory header record.

Reimplemented from TDirectory.

Definition at line 2044 of file TDirectoryFile.cxx.

◆ WriteKeys()

void TDirectoryFile::WriteKeys ( )

virtual

Write Keys linked list on the file.

The linked list of keys (fKeys) is written as a single data record

Reimplemented from TDirectory.

Definition at line 2073 of file TDirectoryFile.cxx.

◆ WriteObjectAny() [1/2]

Int_t TDirectoryFile::WriteObjectAny	(	const void *	obj,
		const char *	classname,
		const char *	name,
		Option_t *	option = `""`,
		Int_t	bufsize = `0`
	)

virtual

Write object from pointer of class classname in this directory.

obj may not derive from TObject. See TDirectoryFile::WriteTObject for comments

Very important note

The value passed as 'obj' needs to be from a pointer to the type described by classname. For example:

TopClass *top;
BottomClass *bottom;
top = bottom;

you can do:

directory->WriteObjectAny(top,"top","name of object");

directory->WriteObjectAny(bottom,"bottom","name of object");

BUT YOU CAN NOT DO the following since it will fail with multiple inheritance:

directory->WriteObjectAny(top,"bottom","name of object");

We STRONGLY recommend to use

TopClass *top = ....;

directory->WriteObject(top,"name of object")

See also remarks in TDirectoryFile::WriteTObject

Reimplemented from TDirectory.

Definition at line 1925 of file TDirectoryFile.cxx.

◆ WriteObjectAny() [2/2]

Int_t TDirectoryFile::WriteObjectAny	(	const void *	obj,
		const TClass *	cl,
		const char *	name,
		Option_t *	option = `""`,
		Int_t	bufsize = `0`
	)

virtual

Write object of class with dictionary cl in this directory.

obj may not derive from TObject To get the TClass* cl pointer, one can use

TClass *cl = TClass::GetClass("classname");

An alternative is to call the function WriteObjectAny above. see TDirectoryFile::WriteTObject for comments

Reimplemented from TDirectory.

Definition at line 1952 of file TDirectoryFile.cxx.

◆ WriteTObject()

Int_t TDirectoryFile::WriteTObject	(	const TObject *	obj,
		const char *	name = `0`,
		Option_t *	option = `""`,
		Int_t	bufsize = `0`
	)

virtual

Write object obj to this directory.

The data structure corresponding to this object is serialized. The corresponding buffer is written to this directory with an associated key with name "name".

Writing an object to a file involves the following steps:

Creation of a support TKey object in the directory. The TKey object creates a TBuffer object.
The TBuffer object is filled via the class::Streamer function.
If the file is compressed (default) a second buffer is created to hold the compressed buffer.
Reservation of the corresponding space in the file by looking in the TFree list of free blocks of the file.
The buffer is written to the file.

By default, the buffersize will be taken from the average buffer size of all objects written to the current file so far. Use TDirectoryFile::SetBufferSize to force a given buffer size.

If a name is specified, it will be the name of the key. If name is not given, the name of the key will be the name as returned by obj->GetName().

The option can be a combination of:

"SingleKey"
"Overwrite"
"WriteDelete" Using the "Overwrite" option a previous key with the same name is overwritten. The previous key is deleted before writing the new object. Using the "WriteDelete" option a previous key with the same name is deleted only after the new object has been written. This option is safer than kOverwrite but it is slower. The "SingleKey" option is only used by TCollection::Write() to write a container with a single key instead of each object in the container with its own key. An object is read from this directory via TDirectoryFile::Get. The function returns the total number of bytes written to the directory. It returns 0 if the object cannot be written.

WARNING: avoid special characters like '^','$','.' in the name as they are used by the regular expression parser (see TRegexp).

Reimplemented from TDirectory.

Definition at line 1812 of file TDirectoryFile.cxx.

Member Data Documentation

◆ fBufferSize

Int_t TDirectoryFile::fBufferSize

protected

Default buffer size to create new TKeys.

Definition at line 40 of file TDirectoryFile.h.

◆ fDatimeC

TDatime TDirectoryFile::fDatimeC

protected

Date and time when directory is created.

Definition at line 36 of file TDirectoryFile.h.

◆ fDatimeM

TDatime TDirectoryFile::fDatimeM

protected

Date and time of last modification.

Definition at line 37 of file TDirectoryFile.h.

◆ fFile

TFile* TDirectoryFile::fFile

protected

Pointer to current file in memory.

Definition at line 44 of file TDirectoryFile.h.

◆ fKeys

TList* TDirectoryFile::fKeys

protected

Pointer to keys list in memory.

Definition at line 45 of file TDirectoryFile.h.

◆ fModified

Bool_t TDirectoryFile::fModified

protected

True if directory has been modified.

Definition at line 34 of file TDirectoryFile.h.

◆ fNbytesKeys

Int_t TDirectoryFile::fNbytesKeys

protected

Number of bytes for the keys.

Definition at line 38 of file TDirectoryFile.h.

◆ fNbytesName

Int_t TDirectoryFile::fNbytesName

protected

Number of bytes in TNamed at creation time.

Definition at line 39 of file TDirectoryFile.h.

◆ fSeekDir

Long64_t TDirectoryFile::fSeekDir

protected

Location of directory on file.

Definition at line 41 of file TDirectoryFile.h.

◆ fSeekKeys

Long64_t TDirectoryFile::fSeekKeys

protected

Location of Keys record on file.

Definition at line 43 of file TDirectoryFile.h.

◆ fSeekParent

Long64_t TDirectoryFile::fSeekParent

protected

Location of parent directory on file.

Definition at line 42 of file TDirectoryFile.h.

◆ fWritable

Bool_t TDirectoryFile::fWritable

protected

True if directory is writable.

Definition at line 35 of file TDirectoryFile.h.

The documentation for this class was generated from the following files:

io/io/inc/TDirectoryFile.h
io/io/src/TDirectoryFile.cxx

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Additional Inherited Members

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ TDirectoryFile() [1/3]

◆ TDirectoryFile() [2/3]

◆ TDirectoryFile() [3/3]

◆ ~TDirectoryFile()

Member Function Documentation

◆ Add()

◆ Append()

◆ AppendKey()

◆ Browse()

◆ Build()

◆ cd()

◆ CleanTargets()

◆ CloneObject()

◆ Close()

◆ Copy()

◆ Delete()

WARNING

◆ FillBuffer()

◆ FindKey()

◆ FindKeyAny()

◆ FindObjectAny()

◆ FindObjectAnyFile()

◆ Get()

The GetObjectMethod

Very important note about inheritance

Example 1 - Normal case:

Example 2 - Special case:

◆ GetBufferSize()

◆ GetCreationDate()

◆ GetDirectory()

◆ GetFile()

◆ GetKey()

◆ GetListOfKeys()

◆ GetModificationDate()

◆ GetNbytesKeys()

◆ GetNkeys()

◆ GetObject()

◆ GetObjectChecked() [1/2]

◆ GetObjectChecked() [2/2]

Very important note

◆ GetObjectUnchecked()

Very important note

◆ GetSeekDir()

◆ GetSeekKeys()

◆ GetSeekParent()

◆ Init()

◆ IsModified()

◆ IsWritable()

◆ ls()

◆ mkdir()

◆ OpenFile()

◆ operator=()

◆ Purge()

◆ ReadAll()

◆ ReadKeys()

◆ ReadTObject()

◆ ResetAfterMerge()

◆ rmdir()

◆ Save()

◆ SaveObjectAs()

◆ SaveSelf()

◆ SetBufferSize()

◆ SetModified()

◆ SetSeekDir()

◆ SetTRefAction()

◆ SetWritable()

◆ Sizeof()

◆ Write() [1/2]

◆ Write() [2/2]

◆ WriteDirHeader()

◆ WriteKeys()