B-tree class.

TBtree inherits from the TSeqCollection ABC.

B-tree Implementation notes

This implements B-trees with several refinements. Most of them can be found in Knuth Vol 3, but some were developed to adapt to restrictions imposed by C++. First, a restatement of Knuth's properties that a B-tree must satisfy, assuming we make the enhancement he suggests in the paragraph at the bottom of page 476. Instead of storing null pointers to non-existent nodes (which Knuth calls the leaves) we utilize the space to store keys. Therefore, what Knuth calls level (l-1) is the bottom of our tree, and we call the nodes at this level LeafNodes. Other nodes are called InnerNodes. The other enhancement we have adopted is in the paragraph at the bottom of page 477: overflow control.

The following are modifications of Knuth's properties on page 478:

Every InnerNode has at most Order keys, and at most Order+1 sub-trees.
Every LeafNode has at most 2*(Order+1) keys.
An InnerNode with k keys has k+1 sub-trees.
Every InnerNode that is not the root has at least InnerLowWaterMark keys.
Every LeafNode that is not the root has at least LeafLowWaterMark keys.
If the root is a LeafNode, it has at least one key.
If the root is an InnerNode, it has at least one key and two sub-trees.
All LeafNodes are the same distance from the root as all the other LeafNodes.
For InnerNode n with key n[i].key, then sub-tree n[i-1].tree contains all keys < n[i].key, and sub-tree n[i].tree contains all keys >= n[i].key.

Order is at least 3.

The values of InnerLowWaterMark and LeafLowWaterMark may actually be set by the user when the tree is initialized, but currently they are set automatically to:

InnerLowWaterMark = ceiling(Order/2)

LeafLowWaterMark = Order - 1

TBtree::Order

Int_t Order()

Definition TBtree.h:96

If the tree is only filled, then all the nodes will be at least 2/3 full. They will almost all be exactly 2/3 full if the elements are added to the tree in order (either increasing or decreasing). [Knuth says McCreight's experiments showed almost 100% memory utilization. I don't see how that can be given the algorithms that Knuth gives. McCreight must have used a different scheme for balancing. [No, he used a different scheme for splitting: he did a two-way split instead of the three way split as we do here. Which means that McCreight does better on insertion of ordered data, but we should do better on insertion of random data.]]

It must also be noted that B-trees were designed for DISK access algorithms, not necessarily in-memory sorting, as we intend it to be used here. However, if the order is kept small (< 6?) any inefficiency is negligible for in-memory sorting. Knuth points out that balanced trees are actually preferable for memory sorting. I'm not sure that I believe this, but it's interesting. Also, deleting elements from balanced binary trees, being beyond the scope of Knuth's book (p. 465), is beyond my scope. B-trees are good enough.

A B-tree is declared to be of a certain ORDER (3 by default). This number determines the number of keys contained in any interior node of the tree. Each interior node will contain ORDER keys, and therefore ORDER+1 pointers to sub-trees. The keys are numbered and indexed 1 to ORDER while the pointers are numbered and indexed 0 to ORDER. The 0th ptr points to the sub-tree of all elements that are less than key[1]. Ptr[1] points to the sub-tree that contains all the elements greater than key[1] and less than key[2]. etc. The array of pointers and keys is allocated as ORDER+1 pairs of keys and nodes, meaning that one key field (key[0]) is not used and therefore wasted. Given that the number of interior nodes is small, that this waste allows fewer cases of special code, and that it is useful in certain of the methods, it was felt to be a worthwhile waste.

The size of the exterior nodes (leaf nodes) does not need to be related to the size of the interior nodes at all. Since leaf nodes contain only keys, they may be as large or small as we like independent of the size of the interior nodes. For no particular reason other than it seems like a good idea, we will allocate 2*(ORDER+1) keys in each leaf node, and they will be numbered and indexed from 0 to 2*ORDER+1. It does have the advantage of keeping the size of the leaf and interior arrays the same, so that if we find allocation and de-allocation of these arrays expensive, we can modify their allocation to use a garbage ring, or something.

Both of these numbers will be run-time constants associated with each tree (each tree at run-time can be of a different order). The variable "order" is the order of the tree, and the inclusive upper limit on the indices of the keys in the interior nodes. The variable "order2" is the inclusive upper limit on the indices of the leaf nodes, and is designed

(1) to keep the sizes of the two kinds of nodes the same;
(2) to keep the expressions involving the arrays of keys looking
    somewhat the same:   lower limit        upper limit
      for inner nodes:        1                order
      for leaf  nodes:        0                order2
    Remember that index 0 of the inner nodes is special.

Currently, order2 = 2*(order+1).

Picture: (also see Knuth Vol 3 pg 478)
 
          +--+--+--+--+--+--...
          |  |  |  |  |  |
parent--->|  |     |     |
          |  |     |     |
          +*-+*-+*-+--+--+--...
           |  |  |
      +----+  |  +-----+
      |       +-----+  |
      V             |  V
      +----------+  |  +----------+
      |          |  |  |          |
this->|          |  |  |          |<--sib
      +----------+  |  +----------+
                    V
                   data

It is conceptually VERY convenient to think of the data as being the very first element of the sib node. Any primitive that tells sib to perform some action on n nodes should include this 'hidden' element. For InnerNodes, the hidden element has (physical) index 0 in the array, and in LeafNodes, the hidden element has (virtual) index -1 in the array. Therefore, there are two 'size' primitives for nodes:

Psize       - the physical size: how many elements are contained in the
              array in the node.
Vsize       - the 'virtual' size; if the node is pointed to by
              element 0 of the parent node, then Vsize == Psize;
              otherwise the element in the parent item that points to this
              node 'belongs' to this node, and Vsize == Psize+1;

Parent nodes are always InnerNodes.

These are the primitive operations on Nodes:

Append(elt)     - adds an element to the end of the array of elements in a
                  node.  It must never be called where appending the element
                  would fill the node.
Split()         - divide a node in two, and create two new nodes.
SplitWith(sib)  - create a third node between this node and the sib node,
                  divvying up the elements of their arrays.
PushLeft(n)     - move n elements into the left sibling
PushRight(n)    - move n elements into the right sibling
BalanceWithRight() - even up the number of elements in the two nodes.
BalanceWithLeft()  - ditto

To allow this implementation of btrees to also be an implementation of sorted arrays/lists, the overhead is included to allow O(log n) access of elements by their rank (‘give me the 5th largest element’). Therefore, each Item keeps track of the number of keys in and below it in the tree (remember, each item's tree is all keys to the RIGHT of the item's own key).

[ [ < 0 1 2 3 > 4 < 5 6 7 > 8 < 9 10 11 12 > ] 13 [ < 14 15 16 > 17 < 18 19 20 > ] ]

4 1 1 1 1 4 1 1 1 5 1 1 1 1 7 3 1 1 1 4 1 1 1

Definition at line 38 of file TBtree.h.

Public Types
typedef TBtreeIter	Iterator_t

Public Types inherited from TCollection
enum	{ kInitCapacity = 16 , kInitHashTableCapacity = 17 }

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
	TBtree (Int_t ordern=3)
	Create a B-tree of certain order (by default 3).

virtual	~TBtree ()
	Delete B-tree.

void	Add (TObject *obj)
	Add object to B-tree.

void	AddAfter (const TObject , TObject obj)

void	AddAt (TObject *obj, Int_t)

void	AddBefore (const TObject , TObject obj)

void	AddFirst (TObject *obj)

void	AddLast (TObject *obj)

TObject *	After (const TObject *obj) const
	Cannot use this method since B-tree decides order.

TObject *	At (Int_t idx) const

TObject *	Before (const TObject *obj) const
	May not use this method since B-tree decides order.

void	Clear (Option_t *option="")
	Remove all objects from B-tree.

void	Delete (Option_t *option="")
	Remove all objects from B-tree AND delete all heap based objects.

TObject *	FindObject (const char *name) const
	Find object using its name (see object's GetName()).

TObject *	FindObject (const TObject *obj) const
	Find object using the objects Compare() member function.

TObject *	First () const

TObject **	GetObjectRef (const TObject *) const

TObject *	Last () const

TIterator *	MakeIterator (Bool_t dir=kIterForward) const
	Returns a B-tree iterator.

TObject *	operator[] (Int_t i) const

Int_t	Order ()

Int_t	Rank (const TObject *obj) const
	Returns the rank of the object in the tree.

TObject *	Remove (TObject *obj)
	Remove an object from the tree.

Public Member Functions inherited from TSeqCollection
virtual	~TSeqCollection ()

virtual Int_t	GetLast () const
	Returns index of last object in collection.

virtual Int_t	IndexOf (const TObject *obj) const
	Return index of object in collection.

virtual Bool_t	IsSorted () const

Int_t	LastIndex () const

Long64_t	Merge (TCollection *list)
	Merge this collection with all collections coming in the input list.

virtual void	RemoveAfter (TObject *after)

virtual TObject *	RemoveAt (Int_t idx)

virtual void	RemoveBefore (TObject *before)

virtual void	RemoveFirst ()

virtual void	RemoveLast ()

void	UnSort ()

Public Member Functions inherited from TCollection
virtual	~TCollection ()
	TNamed destructor.

virtual void	AddAll (const TCollection *col)
	Add all objects from collection col to this collection.

void	AddVector (TObject *obj1,...)
	Add all arguments to the collection.

Bool_t	AssertClass (TClass *cl) const
	Make sure all objects in this collection inherit from class cl.

TIter	begin () const

void	Browse (TBrowser *b)
	Browse this collection (called by TBrowser).

Int_t	Capacity () const

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

Int_t	Compare (const TObject *obj) const
	Compare two TCollection objects.

Bool_t	Contains (const char *name) const

Bool_t	Contains (const TObject *obj) const

virtual void	Draw (Option_t *option="")
	Draw all objects in this collection.

virtual void	Dump () const
	Dump all objects in this collection.

TIter	end () const

virtual Int_t	GetEntries () const

virtual const char *	GetName () const
	Return name of this collection.

virtual Int_t	GetSize () const
	Return the capacity of the collection, i.e.

virtual Int_t	GrowBy (Int_t delta) const
	Increase the collection's capacity by delta slots.

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

Bool_t	IsArgNull (const char where, const TObject obj) const
	Returns true if object is a null pointer.

virtual Bool_t	IsEmpty () const

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

Bool_t	IsOwner () const

Bool_t	IsSortable () const

R__ALWAYS_INLINE Bool_t	IsUsingRWLock () const

virtual void	ls (Option_t *option="") const
	List (ls) all objects in this collection.

virtual TIterator *	MakeReverseIterator () const

virtual Bool_t	Notify ()
	'Notify' all objects in this collection.

TObject *	operator() (const char *name) const
	Find an object in this collection by name.

virtual void	Paint (Option_t *option="")
	Paint all objects in this collection.

virtual void	Print (Option_t option, const char wildcard, Int_t recurse=1) const
	Print the collection header and its elements that match the wildcard.

virtual void	Print (Option_t *option, Int_t recurse) const
	Print the collection header and its elements.

virtual void	Print (Option_t *option, TPRegexp &regexp, Int_t recurse=1) const
	Print the collection header and its elements that match the regexp.

virtual void	Print (Option_t *option="") const
	Default print for collections, calls Print(option, 1).

virtual void	RecursiveRemove (TObject *obj)
	Remove object from this collection and recursively remove the object from all other objects (and collections).

void	RemoveAll ()

virtual void	RemoveAll (TCollection *col)
	Remove all objects in collection col from this collection.

void	SetCurrentCollection ()
	Set this collection to be the globally accessible collection.

void	SetName (const char *name)

virtual void	SetOwner (Bool_t enable=kTRUE)
	Set whether this collection is the owner (enable==true) of its content.

virtual bool	UseRWLock (Bool_t enable=true)
	Set this collection to use a RW lock upon access, making it thread safe.

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
	Write all objects in this collection.

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
	Write all objects in this collection.

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

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	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 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.

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).

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).

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.

Protected Member Functions
void	DecrNofKeys ()

Int_t	IdxAdd (const TObject &obj)
	Add object and return its index in the tree.

void	IncrNofKeys ()

Protected Member Functions inherited from TSeqCollection
	TSeqCollection ()

virtual void	Changed ()

Protected Member Functions inherited from TCollection
	TCollection ()

virtual const char *	GetCollectionEntryName (TObject *entry) const
	For given collection entry return the string that is used to identify the object and, potentially, perform wildcard/regexp filtering on.

virtual void	PrintCollectionEntry (TObject entry, Option_t option, Int_t recurse) const
	Print the collection entry.

virtual void	PrintCollectionHeader (Option_t *option) const
	Print the collection header.

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 ()

Private Member Functions
void	Init (Int_t i)
	Initialize a B-tree.

void	RootIsEmpty ()
	If root is empty clean up its space.

void	RootIsFull ()
	The root of the tree is full.

Private Attributes
Int_t	fInnerLowWaterMark

Int_t	fInnerMaxIndex

Int_t	fLeafLowWaterMark

Int_t	fLeafMaxIndex

Int_t	fOrder

Int_t	fOrder2

TBtNode *	fRoot

Friends
class	TBtInnerNode

class	TBtLeafNode

class	TBtNode

Additional Inherited Members
Static Public Member Functions inherited from TSeqCollection
static Int_t	ObjCompare (TObject a, TObject b)
	Compare to objects in the collection. Use member Compare() of object a.

static void	QSort (TObject **a, Int_t first, Int_t last)
	Sort array of TObject pointers using a quicksort algorithm.

static void	QSort (TObject a, Int_t nBs, TObject *b, Int_t first, Int_t last)
	Sort array a of TObject pointers using a quicksort algorithm.

static void	QSort (TObject a, TObject b, Int_t first, Int_t last)

Static Public Member Functions inherited from TCollection
static void	EmptyGarbageCollection ()
	Do the garbage collection.

static void	GarbageCollect (TObject *obj)
	Add to the list of things to be cleaned up.

static TCollection *	GetCurrentCollection ()
	Return the globally accessible collection.

static void	StartGarbageCollection ()
	Set up for garbage collection.

Static Public Member Functions inherited from TObject
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 Types inherited from TCollection
enum	EStatusBits { kIsOwner = BIT(14) , kUseRWLock = BIT(16) }

Protected Types inherited from TObject
enum	{ kOnlyPrepStep = BIT(3) }

Protected Attributes inherited from TSeqCollection
Bool_t	fSorted

Protected Attributes inherited from TCollection
TString	fName

Int_t	fSize

#include <TBtree.h>

Inheritance diagram for TBtree:

[legend]

Member Typedef Documentation

◆ Iterator_t

typedef TBtreeIter TBtree::Iterator_t

Definition at line 69 of file TBtree.h.

Constructor & Destructor Documentation

◆ TBtree()

TBtree::TBtree ( Int_t ordern = 3 )

Create a B-tree of certain order (by default 3).

Definition at line 180 of file TBtree.cxx.

◆ ~TBtree()

TBtree::~TBtree ( )

virtual

Delete B-tree.

Objects are not deleted unless the TBtree is the owner (set via SetOwner()).

Definition at line 189 of file TBtree.cxx.

Member Function Documentation

◆ Add()

void TBtree::Add ( TObject * obj )

virtual

Add object to B-tree.

Reimplemented from TSeqCollection.

Definition at line 200 of file TBtree.cxx.

◆ AddAfter()

void TBtree::AddAfter	(	const TObject *	,
		TObject *	obj
	)

inlinevirtual

Implements TSeqCollection.

Definition at line 84 of file TBtree.h.

◆ AddAt()

void TBtree::AddAt	(	TObject *	obj,
		Int_t
	)

inlinevirtual

Implements TSeqCollection.

Definition at line 83 of file TBtree.h.

◆ AddBefore()

void TBtree::AddBefore	(	const TObject *	,
		TObject *	obj
	)

inlinevirtual

Implements TSeqCollection.

Definition at line 85 of file TBtree.h.

◆ AddFirst()

void TBtree::AddFirst ( TObject * obj )

inlinevirtual

Implements TSeqCollection.

Definition at line 81 of file TBtree.h.

◆ AddLast()

void TBtree::AddLast ( TObject * obj )

inlinevirtual

Implements TSeqCollection.

Definition at line 82 of file TBtree.h.

◆ After()

TObject * TBtree::After ( const TObject * obj ) const

virtual

Cannot use this method since B-tree decides order.

Implements TSeqCollection.

Definition at line 228 of file TBtree.cxx.

◆ At()

TObject * TBtree::At ( Int_t idx ) const

inlinevirtual

Implements TSeqCollection.

Definition at line 375 of file TBtree.h.

◆ Before()

TObject * TBtree::Before ( const TObject * obj ) const

virtual

May not use this method since B-tree decides order.

Implements TSeqCollection.

Definition at line 237 of file TBtree.cxx.

◆ Clear()

void TBtree::Clear ( Option_t * option = "" )

virtual

Remove all objects from B-tree.

Does NOT delete objects unless the TBtree is the owner (set via SetOwner()).

Implements TCollection.

Definition at line 247 of file TBtree.cxx.

◆ DecrNofKeys()

void TBtree::DecrNofKeys ( )

inlineprotected

Definition at line 61 of file TBtree.h.

◆ Delete()

void TBtree::Delete ( Option_t * option = "" )

virtual

Remove all objects from B-tree AND delete all heap based objects.

Implements TCollection.

Definition at line 260 of file TBtree.cxx.

◆ FindObject() [1/2]

TObject * TBtree::FindObject ( const char * name ) const

virtual

Find object using its name (see object's GetName()).

Requires sequential search of complete tree till object is found.

Reimplemented from TCollection.

Definition at line 275 of file TBtree.cxx.

◆ FindObject() [2/2]

TObject * TBtree::FindObject ( const TObject * obj ) const

virtual

Find object using the objects Compare() member function.

Reimplemented from TCollection.

Definition at line 283 of file TBtree.cxx.

◆ First()

TObject * TBtree::First ( ) const

inlinevirtual

Implements TSeqCollection.

Definition at line 380 of file TBtree.h.

◆ GetObjectRef()

TObject ** TBtree::GetObjectRef ( const TObject * ) const

inlinevirtual

Implements TCollection.

Definition at line 77 of file TBtree.h.

◆ IdxAdd()

Int_t TBtree::IdxAdd ( const TObject & obj )

protected

Add object and return its index in the tree.

Definition at line 301 of file TBtree.cxx.

◆ IncrNofKeys()

void TBtree::IncrNofKeys ( )

inlineprotected

Definition at line 60 of file TBtree.h.

◆ Init()

void TBtree::Init ( Int_t i )

private

Initialize a B-tree.

Definition at line 344 of file TBtree.cxx.

◆ Last()

TObject * TBtree::Last ( ) const

inlinevirtual

Implements TSeqCollection.

Definition at line 385 of file TBtree.h.

◆ MakeIterator()

TIterator * TBtree::MakeIterator ( Bool_t dir = kIterForward ) const

virtual

Returns a B-tree iterator.

Implements TCollection.

Definition at line 385 of file TBtree.cxx.

◆ operator[]()

TObject * TBtree::operator[] ( Int_t i ) const

inline

Definition at line 370 of file TBtree.h.

◆ Order()

Int_t TBtree::Order ( )

inline

Definition at line 96 of file TBtree.h.

◆ Rank()

Int_t TBtree::Rank ( const TObject * obj ) const

Returns the rank of the object in the tree.

Definition at line 393 of file TBtree.cxx.

◆ Remove()

TObject * TBtree::Remove ( TObject * obj )

virtual

Remove an object from the tree.

Implements TCollection.

Definition at line 408 of file TBtree.cxx.

◆ RootIsEmpty()

void TBtree::RootIsEmpty ( )

private

If root is empty clean up its space.

Definition at line 441 of file TBtree.cxx.

◆ RootIsFull()

void TBtree::RootIsFull ( )

private

The root of the tree is full.

Create an InnerNode that points to it, and then inform the InnerNode that it is full.

Definition at line 430 of file TBtree.cxx.

Friends And Related Symbol Documentation

◆ TBtInnerNode

friend class TBtInnerNode

friend

Definition at line 41 of file TBtree.h.

◆ TBtLeafNode

friend class TBtLeafNode

friend

Definition at line 42 of file TBtree.h.

◆ TBtNode

friend class TBtNode

friend

Definition at line 40 of file TBtree.h.

Member Data Documentation

◆ fInnerLowWaterMark

Int_t TBtree::fInnerLowWaterMark

private

Definition at line 50 of file TBtree.h.

◆ fInnerMaxIndex

Int_t TBtree::fInnerMaxIndex

private

Definition at line 52 of file TBtree.h.

◆ fLeafLowWaterMark

Int_t TBtree::fLeafLowWaterMark

private

Definition at line 51 of file TBtree.h.

◆ fLeafMaxIndex

Int_t TBtree::fLeafMaxIndex

private

Definition at line 53 of file TBtree.h.

◆ fOrder

Int_t TBtree::fOrder

private

Definition at line 47 of file TBtree.h.

◆ fOrder2

Int_t TBtree::fOrder2

private

Definition at line 48 of file TBtree.h.

◆ fRoot

TBtNode* TBtree::fRoot

private

Definition at line 45 of file TBtree.h.

core/cont/inc/TBtree.h

core/cont/src/TBtree.cxx

B-tree Implementation notes

Public Types

Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Friends

Additional Inherited Members

Member Typedef Documentation

◆ Iterator_t

Constructor & Destructor Documentation

◆ TBtree()

◆ ~TBtree()

Member Function Documentation

◆ Add()

◆ AddAfter()

◆ AddAt()

◆ AddBefore()

◆ AddFirst()

◆ AddLast()

◆ After()

◆ At()

◆ Before()

◆ Clear()

◆ DecrNofKeys()

◆ Delete()

◆ FindObject() [1/2]

◆ FindObject() [2/2]

◆ First()

◆ GetObjectRef()

◆ IdxAdd()

◆ IncrNofKeys()

◆ Init()

◆ Last()

◆ MakeIterator()

◆ operator[]()

◆ Order()

◆ Rank()

◆ Remove()

◆ RootIsEmpty()

◆ RootIsFull()

Friends And Related Symbol Documentation

◆ TBtInnerNode

◆ TBtLeafNode

◆ TBtNode

Member Data Documentation

◆ fInnerLowWaterMark

◆ fInnerMaxIndex

◆ fLeafLowWaterMark

◆ fLeafMaxIndex

◆ fOrder

◆ fOrder2

◆ fRoot