TTree::TClusterIterator Class Reference

Helper class to iterate over cluster of baskets.

Note

In contrast to class TListIter, looping here must NOT be done using while (iter()) or while (iter.Next()) that would lead to an infinite loop, but rather using while( (auto clusterStart = iter()) < tree->GetEntries() ).

See also

TTree::GetClusterIterator

Definition at line 281 of file TTree.h.

Public Member Functions
Long64_t	GetNextEntry ()
Long64_t	GetStartEntry ()
Long64_t	Next ()
	Move on to the next cluster and return the starting entry of this next cluster.
Long64_t	operator() ()
Long64_t	Previous ()
	Move on to the previous cluster and return the starting entry of this previous cluster.

Protected Member Functions
	TClusterIterator (TTree *tree, Long64_t firstEntry)
	Regular constructor.

Private Member Functions
Long64_t	GetEstimatedClusterSize ()
	Estimate the cluster size.

Private Attributes
Int_t	fClusterRange
Long64_t	fEstimatedSize
Long64_t	fNextEntry
Long64_t	fStartEntry
TTree *	fTree

Friends
class	TTree

#include <TTree.h>

Constructor & Destructor Documentation

TClusterIterator()

TTree::TClusterIterator::TClusterIterator ( TTree * tree, Long64_t firstEntry )

protected

Regular constructor.

TTree is not set as const, since we might modify if it is a TChain.

Definition at line 554 of file TTree.cxx.

Member Function Documentation

GetEstimatedClusterSize()

Long64_t TTree::TClusterIterator::GetEstimatedClusterSize ( )

private

Estimate the cluster size.

In almost all cases, this quickly returns the size of the auto-flush in the TTree.

However, in the case where the cluster size was not fixed (old files and case where autoflush was explicitly set to zero), we need estimate a cluster size in relation to the size of the cache.

After this value is calculated once for the TClusterIterator, it is cached and reused in future calls.

Definition at line 605 of file TTree.cxx.

GetNextEntry()

Long64_t TTree::TClusterIterator::GetNextEntry ( )

inline

Definition at line 319 of file TTree.h.

GetStartEntry()

Long64_t TTree::TClusterIterator::GetStartEntry ( )

inline

Definition at line 314 of file TTree.h.

Next()

Long64_t TTree::TClusterIterator::Next

(

)

Move on to the next cluster and return the starting entry of this next cluster.

Definition at line 644 of file TTree.cxx.

operator()()

Long64_t TTree::TClusterIterator::operator() ( )

inline

Definition at line 323 of file TTree.h.

Previous()

Long64_t TTree::TClusterIterator::Previous

(

)

Move on to the previous cluster and return the starting entry of this previous cluster.

Definition at line 688 of file TTree.cxx.

Friends And Related Symbol Documentation

TTree

friend class TTree

friend

Definition at line 293 of file TTree.h.

Member Data Documentation

fClusterRange

Int_t TTree::TClusterIterator::fClusterRange

private

Definition at line 285 of file TTree.h.

fEstimatedSize

Long64_t TTree::TClusterIterator::fEstimatedSize

private

Definition at line 288 of file TTree.h.

fNextEntry

Long64_t TTree::TClusterIterator::fNextEntry

private

Definition at line 287 of file TTree.h.

fStartEntry

Long64_t TTree::TClusterIterator::fStartEntry

private

Definition at line 286 of file TTree.h.

fTree

TTree* TTree::TClusterIterator::fTree

private

Definition at line 284 of file TTree.h.

Libraries for TTree::TClusterIterator:

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

• tree/tree/inc/TTree.h
• tree/tree/src/TTree.cxx