A TRefTable maintains the association between a referenced object and the parent object supporting this referenced object.

The parent object is typically a branch of a TTree. For each object referenced in a TTree entry, the corresponding entry in the TTree's TBranchRef::fRefTable contains the index of the branch that needs to be loaded to bring the object into memory.

Persistency of a TRefTable is split into two parts:

entry specific information is stored (read) by FillBuffer (ReadBuffer). For each referenced object the object's fUniqueID and the referencing TRef::fPID is stored (to allow the TRefTable to autoload references created by different processes).
non-entry specific, i.e. global information is stored (read) by the Streamer function. This comprises all members marked as persistent.

As TObject::fUniqueID is only unique for a given TProcessID, a table of unique IDs is kept for each used TProcessID. There is no natural order of TProcessIDs, so TRefTable stores a vector of the TGUID of all known TProcessIDs in fProcessGUIDs; the index of a TProcessID in this vector defines the index of the auto-loading info in fParentIDs for that TProcessID. The mapping of TProcessID* to index is cached for quick non-persistent lookup.

Definition at line 35 of file TRefTable.h.

Public Types
enum	EStatusBits { kHaveWarnedReadingOld = (1ULL << ( 14 )) }

Public Types inherited from TObject
enum	{ kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 , kBitMask = 0x00ffffff }

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

enum	EDeprecatedStatusBits { kObjInCanvas = (1ULL << ( 3 )) }

enum	EStatusBits { kCanDelete = (1ULL << ( 0 )) , kMustCleanup = (1ULL << ( 3 )) , kIsReferenced = (1ULL << ( 4 )) , kHasUUID = (1ULL << ( 5 )) , kCannotPick = (1ULL << ( 6 )) , kNoContextMenu = (1ULL << ( 8 )) , kInvalidObject = (1ULL << ( 13 )) }

Public Member Functions
	TRefTable ()
	Default constructor for I/O.

	TRefTable (const TRefTable &)=delete

	TRefTable (TObject *owner, Int_t size)
	Create a TRefTable with initial size.

virtual	~TRefTable ()
	Destructor.

virtual Int_t	Add (Int_t uid, TProcessID *context=nullptr)
	Add a new uid to the table.

void	Clear (Option_t *="") override
	Clear all entries in the table.

virtual Int_t	Expand (Int_t pid, Int_t newsize)
	Expand fParentIDs to newsize for ProcessID pid.

virtual void	FillBuffer (TBuffer &b)
	Fill buffer b with the fN elements in fParentdIDs.

Int_t	GetN (Int_t pid) const

Int_t	GetNumPIDs () const

TObject *	GetOwner () const

TObject *	GetParent (Int_t uid, TProcessID *context=nullptr) const
	Return object corresponding to uid.

TObjArray *	GetParents () const

Int_t	GetSize (Int_t pid) const

UInt_t	GetUID () const

TProcessID *	GetUIDContext () const

TClass *	IsA () const override

Bool_t	Notify () override
	This function is called by TRef::Streamer or TStreamerInfo::ReadBuffer when reading a reference.

TRefTable &	operator= (const TRefTable &)=delete

virtual void	ReadBuffer (TBuffer &b)
	Fill buffer b with the fN elements in fParentdIDs.

virtual void	Reset (Option_t *="")
	Clear all entries in the table.

virtual Int_t	SetParent (const TObject *parent, Int_t branchID)
	– Set current parent object, typically a branch of a tree.

virtual void	SetUID (UInt_t uid, TProcessID *context=nullptr)

void	Streamer (TBuffer &) override
	Stream an object of class TRefTable.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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.

virtual void	Browse (TBrowser *b)
	Browse object. May be overridden for another default action.

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 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 abstract method.

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

virtual void	Delete (Option_t *option="")
	Delete this object.

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

virtual void	Draw (Option_t *option="")
	Default Draw method for all objects.

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 with: `gROOT->SetSelectedPad(c1)`.

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=nullptr)
	Execute method on this object with the given parameter string, e.g.

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=nullptr)
	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 TObject *	FindObject (const char *name) const
	Must be redefined in derived classes.

virtual TObject *	FindObject (const TObject *obj) const
	Must be redefined in derived classes.

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 const char *	GetName () const
	Returns 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 Option_t *	GetOption () const

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

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.

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

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)

Bool_t	IsDestructed () const
	IsDestructed.

virtual Bool_t	IsEqual (const TObject *obj) const
	Default equal comparison (objects are equal if they have the same address in memory).

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

R__ALWAYS_INLINE Bool_t	IsOnHeap () const

virtual Bool_t	IsSortable () const

R__ALWAYS_INLINE Bool_t	IsZombie () const

virtual void	ls (Option_t *option="") const
	The ls function lists the contents of a class on stdout.

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).

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, void vp)
	Only called by placement new when throwing an exception.

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

void	operator delete[] (void ptr, void vp)
	Only called by placement new[] when throwing an exception.

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	Paint (Option_t *option="")
	This method must be overridden if a class wants to paint itself.

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

virtual void	Print (Option_t *option="") const
	This method must be overridden when a class wants to print itself.

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

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove this object from a list.

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.

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

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.

virtual Int_t	Write (const char *name=nullptr, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory.

virtual Int_t	Write (const char *name=nullptr, Int_t option=0, Int_t bufsize=0) const
	Write this object to the current directory.

Static Public Member Functions
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

static TRefTable *	GetRefTable ()
	Static function returning the current TRefTable.

static void	SetRefTable (TRefTable *table)
	Static function setting the current TRefTable.

Static Public Member Functions inherited from TObject
static TClass *	Class ()

static const char *	Class_Name ()

static constexpr Version_t	Class_Version ()

static const char *	DeclFileName ()

static Longptr_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
Int_t	AddInternalIdxForPID (TProcessID *procid)
	Add the internal index for fProcessIDs, fAllocSize, etc given a PID.

virtual Int_t	ExpandForIID (Int_t iid, Int_t newsize)
	Expand fParentIDs to newsize for internel ProcessID index iid.

void	ExpandPIDs (Int_t numpids)
	Expand the arrays of managed PIDs.

Int_t	FindPIDGUID (const char *guid) const
	Get fProcessGUIDs' index of the TProcessID with GUID guid.

Int_t	GetInternalIdxForPID (Int_t pid) const
	Get the index for fProcessIDs, fAllocSize, etc given a PID.

Int_t	GetInternalIdxForPID (TProcessID *procid) const
	Get the index for fProcessIDs, fAllocSize, etc given a PID.

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
Int_t *	fAllocSize
	number of known ProcessIDs

Int_t	fDefaultSize
	current parent ID in fParents (latest call to SetParent)

std::vector< Int_t >	fMapPIDtoInternal

Int_t *	fN
	[fNumPIDs] allocated size of array fParentIDs for each ProcessID

Int_t	fNumPIDs

TObject *	fOwner

Int_t	fParentID
	[fNumPIDs][fAllocSize] array of Parent IDs

Int_t **	fParentIDs
	[fNumPIDs] current maximum number of IDs in array fParentIDs for each ProcessID

TObjArray *	fParents

std::vector< std::string >	fProcessGUIDs

Int_t	fSize
	TProcessID the current uid is referring to.

UInt_t	fUID
	default size for a new PID array

TProcessID *	fUIDContext
	Current uid (set by TRef::GetObject)

Static Protected Attributes
static TRefTable *	fgRefTable = nullptr
	cache of pid to index in fProcessGUIDs

Additional Inherited Members
Protected Types inherited from TObject
enum	{ kOnlyPrepStep = (1ULL << ( 3 )) }

#include <TRefTable.h>

Inheritance diagram for TRefTable:

[legend]

Member Enumeration Documentation

◆ EStatusBits

enum TRefTable::EStatusBits

Enumerator
kHaveWarnedReadingOld

Definition at line 62 of file TRefTable.h.

Constructor & Destructor Documentation

◆ TRefTable() [1/3]

TRefTable::TRefTable ( )

Default constructor for I/O.

Definition at line 52 of file TRefTable.cxx.

◆ TRefTable() [2/3]

TRefTable::TRefTable	(	TObject *	owner,
		Int_t	size
	)

Create a TRefTable with initial size.

Definition at line 61 of file TRefTable.cxx.

◆ ~TRefTable()

TRefTable::~TRefTable ( )

virtual

Destructor.

Definition at line 71 of file TRefTable.cxx.

◆ TRefTable() [3/3]

TRefTable::TRefTable ( const TRefTable & )

delete

Member Function Documentation

◆ Add()

Int_t TRefTable::Add	(	Int_t	uid,
		TProcessID *	context = `nullptr`
	)

virtual

Add a new uid to the table.

we add a new pair (uid,fparent) to the map This function is called by TObject::Streamer or TStreamerInfo::WriteBuffer

Definition at line 88 of file TRefTable.cxx.

◆ AddInternalIdxForPID()

Int_t TRefTable::AddInternalIdxForPID ( TProcessID * procid )

protected

Add the internal index for fProcessIDs, fAllocSize, etc given a PID.

Definition at line 119 of file TRefTable.cxx.

◆ Class()

static TClass * TRefTable::Class ( )

static

Returns: TClass describing this class

◆ Class_Name()

static const char * TRefTable::Class_Name ( )

static

Returns: Name of this class

◆ Class_Version()

static constexpr Version_t TRefTable::Class_Version ( )

inlinestaticconstexpr

Returns: Version of this class

Definition at line 93 of file TRefTable.h.

◆ Clear()

void TRefTable::Clear ( Option_t * = "" )

overridevirtual

Clear all entries in the table.

Reimplemented from TObject.

Definition at line 145 of file TRefTable.cxx.

◆ DeclFileName()

static const char * TRefTable::DeclFileName ( )

inlinestatic

Returns: Name of the file containing the class declaration

Definition at line 93 of file TRefTable.h.

◆ Expand()

Int_t TRefTable::Expand	(	Int_t	pid,
		Int_t	newsize
	)

virtual

Expand fParentIDs to newsize for ProcessID pid.

Definition at line 157 of file TRefTable.cxx.

◆ ExpandForIID()

Int_t TRefTable::ExpandForIID	(	Int_t	iid,
		Int_t	newsize
	)

protectedvirtual

Expand fParentIDs to newsize for internel ProcessID index iid.

Definition at line 167 of file TRefTable.cxx.

◆ ExpandPIDs()

void TRefTable::ExpandPIDs ( Int_t numpids )

protected

Expand the arrays of managed PIDs.

Definition at line 193 of file TRefTable.cxx.

◆ FillBuffer()

void TRefTable::FillBuffer ( TBuffer & b )

virtual

Fill buffer b with the fN elements in fParentdIDs.

This function is called by TBranchRef::FillLeaves.

Definition at line 225 of file TRefTable.cxx.

◆ FindPIDGUID()

Int_t TRefTable::FindPIDGUID ( const char * guid ) const

protected

Get fProcessGUIDs' index of the TProcessID with GUID guid.

Definition at line 238 of file TRefTable.cxx.

◆ GetInternalIdxForPID() [1/2]

Int_t TRefTable::GetInternalIdxForPID ( Int_t pid ) const

protected

Get the index for fProcessIDs, fAllocSize, etc given a PID.

Uses fMapPIDtoInternal and the pid's GUID / fProcessGUID

Definition at line 278 of file TRefTable.cxx.

◆ GetInternalIdxForPID() [2/2]

Int_t TRefTable::GetInternalIdxForPID ( TProcessID * procid ) const

protected

Get the index for fProcessIDs, fAllocSize, etc given a PID.

Uses fMapPIDtoInternal and the pid's GUID / fProcessGUID

Definition at line 269 of file TRefTable.cxx.

◆ GetN()

Int_t TRefTable::GetN ( Int_t pid ) const

inline

Definition at line 80 of file TRefTable.h.

◆ GetNumPIDs()

Int_t TRefTable::GetNumPIDs ( ) const

inline

Definition at line 78 of file TRefTable.h.

◆ GetOwner()

TObject * TRefTable::GetOwner ( ) const

inline

Definition at line 81 of file TRefTable.h.

◆ GetParent()

TObject * TRefTable::GetParent	(	Int_t	uid,
		TProcessID *	context = `nullptr`
	)		const

Return object corresponding to uid.

Definition at line 249 of file TRefTable.cxx.

◆ GetParents()

TObjArray * TRefTable::GetParents ( ) const

inline

Definition at line 83 of file TRefTable.h.

◆ GetRefTable()

TRefTable * TRefTable::GetRefTable ( )

static

Static function returning the current TRefTable.

Definition at line 287 of file TRefTable.cxx.

◆ GetSize()

Int_t TRefTable::GetSize ( Int_t pid ) const

inline

Definition at line 79 of file TRefTable.h.

◆ GetUID()

UInt_t TRefTable::GetUID ( ) const

inline

Definition at line 84 of file TRefTable.h.

◆ GetUIDContext()

TProcessID * TRefTable::GetUIDContext ( ) const

inline

Definition at line 85 of file TRefTable.h.

◆ IsA()

TClass * TRefTable::IsA ( ) const

inlineoverridevirtual

Returns: TClass describing current object

Reimplemented from TObject.

Definition at line 93 of file TRefTable.h.

◆ Notify()

Bool_t TRefTable::Notify ( )

overridevirtual

This function is called by TRef::Streamer or TStreamerInfo::ReadBuffer when reading a reference.

This function, in turns, notifies the TRefTable owner for action. eg, when the owner is a TBranchRef, TBranchRef::Notify is called to read the branch containing the referenced object.

Reimplemented from TObject.

Definition at line 299 of file TRefTable.cxx.

◆ operator=()

TRefTable & TRefTable::operator= ( const TRefTable & )

delete

◆ ReadBuffer()

void TRefTable::ReadBuffer ( TBuffer & b )

virtual

Fill buffer b with the fN elements in fParentdIDs.

This function is called by TBranchRef::ReadLeaves

Definition at line 308 of file TRefTable.cxx.

◆ Reset()

void TRefTable::Reset ( Option_t * = "" )

virtual

Clear all entries in the table.

Definition at line 345 of file TRefTable.cxx.

◆ SetParent()

Int_t TRefTable::SetParent	(	const TObject *	parent,
		Int_t	branchID
	)

virtual

– Set current parent object, typically a branch of a tree.

This function is called by TBranchElement::Fill() and by TBranchElement::GetEntry().

Definition at line 357 of file TRefTable.cxx.

◆ SetRefTable()

void TRefTable::SetRefTable ( TRefTable * table )

static

Static function setting the current TRefTable.

Definition at line 383 of file TRefTable.cxx.

◆ SetUID()

virtual void TRefTable::SetUID	(	UInt_t	uid,
		TProcessID *	context = `nullptr`
	)

inlinevirtual

Definition at line 91 of file TRefTable.h.

◆ Streamer()

void TRefTable::Streamer ( TBuffer & R__b )

overridevirtual

Stream an object of class TRefTable.

Reimplemented from TObject.

Definition at line 391 of file TRefTable.cxx.

◆ StreamerNVirtual()

void TRefTable::StreamerNVirtual ( TBuffer & ClassDef_StreamerNVirtual_b )

inline

Definition at line 93 of file TRefTable.h.

Member Data Documentation

◆ fAllocSize

Int_t* TRefTable::fAllocSize

protected

number of known ProcessIDs

Definition at line 39 of file TRefTable.h.

◆ fDefaultSize

Int_t TRefTable::fDefaultSize

protected

current parent ID in fParents (latest call to SetParent)

Definition at line 43 of file TRefTable.h.

◆ fgRefTable

TRefTable * TRefTable::fgRefTable = nullptr

staticprotected

cache of pid to index in fProcessGUIDs

Definition at line 51 of file TRefTable.h.

◆ fMapPIDtoInternal

std::vector<Int_t> TRefTable::fMapPIDtoInternal

protected

Definition at line 50 of file TRefTable.h.

◆ fN

Int_t* TRefTable::fN

protected

[fNumPIDs] allocated size of array fParentIDs for each ProcessID

Definition at line 40 of file TRefTable.h.

◆ fNumPIDs

Int_t TRefTable::fNumPIDs

protected

Definition at line 38 of file TRefTable.h.

◆ fOwner

TObject* TRefTable::fOwner

protected

Definition at line 48 of file TRefTable.h.

◆ fParentID

Int_t TRefTable::fParentID

protected

[fNumPIDs][fAllocSize] array of Parent IDs

Definition at line 42 of file TRefTable.h.

◆ fParentIDs

Int_t** TRefTable::fParentIDs

protected

[fNumPIDs] current maximum number of IDs in array fParentIDs for each ProcessID

Definition at line 41 of file TRefTable.h.

◆ fParents

TObjArray* TRefTable::fParents

protected

Definition at line 47 of file TRefTable.h.

◆ fProcessGUIDs

std::vector<std::string> TRefTable::fProcessGUIDs

protected

Definition at line 49 of file TRefTable.h.

◆ fSize

Int_t TRefTable::fSize

protected

TProcessID the current uid is referring to.

Definition at line 46 of file TRefTable.h.

◆ fUID

UInt_t TRefTable::fUID

protected

default size for a new PID array

Definition at line 44 of file TRefTable.h.

◆ fUIDContext

TProcessID* TRefTable::fUIDContext

protected

Current uid (set by TRef::GetObject)

Definition at line 45 of file TRefTable.h.

Libraries for TRefTable:

[legend]

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

core/cont/inc/TRefTable.h
core/cont/src/TRefTable.cxx

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Additional Inherited Members

Member Enumeration Documentation

◆ EStatusBits

Constructor & Destructor Documentation

◆ TRefTable() [1/3]

◆ TRefTable() [2/3]

◆ ~TRefTable()

◆ TRefTable() [3/3]

Member Function Documentation

◆ Add()

◆ AddInternalIdxForPID()

◆ Class()

◆ Class_Name()

◆ Class_Version()

◆ Clear()

◆ DeclFileName()

◆ Expand()

◆ ExpandForIID()

◆ ExpandPIDs()

◆ FillBuffer()

◆ FindPIDGUID()

◆ GetInternalIdxForPID() [1/2]

◆ GetInternalIdxForPID() [2/2]

◆ GetN()

◆ GetNumPIDs()

◆ GetOwner()

◆ GetParent()

◆ GetParents()

◆ GetRefTable()

◆ GetSize()

◆ GetUID()

◆ GetUIDContext()

◆ IsA()

◆ Notify()

◆ operator=()

◆ ReadBuffer()

◆ Reset()

◆ SetParent()

◆ SetRefTable()

◆ SetUID()

◆ Streamer()

◆ StreamerNVirtual()

Member Data Documentation

◆ fAllocSize

◆ fDefaultSize

◆ fgRefTable

◆ fMapPIDtoInternal

◆ fN

◆ fNumPIDs

◆ fOwner

◆ fParentID

◆ fParentIDs

◆ fParents

◆ fProcessGUIDs

◆ fSize

◆ fUID

◆ fUIDContext