From 7c51142e5eba6ccd4f8a203dd90255722a430127 Mon Sep 17 00:00:00 2001
From: Rene Brun <Rene.Brun@cern.ch>
Date: Thu, 15 Jun 2006 10:02:13 +0000
Subject: [PATCH] Speed improvement, keeping the total size of teh branches in
the cache as a data member instead of computing this value every time
FillBuffer is called.
git-svn-id: http://root.cern.ch/svn/root/trunk@15440 27541ba8-7e3a-0410-8455-c3a389f83636
---
tree/inc/TTreeFilePrefetch.h | 3 ++-
tree/src/TTreeFilePrefetch.cxx | 27 +++++++++++++--------------
2 files changed, 15 insertions(+), 15 deletions(-)
diff --git a/tree/inc/TTreeFilePrefetch.h b/tree/inc/TTreeFilePrefetch.h
index 3552bcb0497..0a4117766fa 100644
--- a/tree/inc/TTreeFilePrefetch.h
+++ b/tree/inc/TTreeFilePrefetch.h
@@ -1,4 +1,4 @@
-// @(#)root/tree:$Name: $:$Id: TTreeFilePrefetch.h,v 1.4 2006/06/14 13:15:55 brun Exp $
+// @(#)root/tree:$Name: $:$Id: TTreeFilePrefetch.h,v 1.5 2006/06/15 07:59:19 brun Exp $
// Author: Rene Brun 04/06/2006
/*************************************************************************
@@ -34,6 +34,7 @@ protected:
Long64_t fEntryMin; //! first entry in the cache
Long64_t fEntryMax; //! last entry in the cache
Long64_t fEntryNext; //! next entry number where cache must be filled
+ Long64_t fZipBytes; //! Total compressed size of branches in cache
Int_t fNbranches; //! Number of branches in the cache
TBranch **fBranches; //! [fNbranches] List of branches to be stored in the cache
Bool_t fIsLearning; //! true if cache is in learning mode
diff --git a/tree/src/TTreeFilePrefetch.cxx b/tree/src/TTreeFilePrefetch.cxx
index 0bcf5942101..675612128e3 100644
--- a/tree/src/TTreeFilePrefetch.cxx
+++ b/tree/src/TTreeFilePrefetch.cxx
@@ -1,4 +1,4 @@
-// @(#)root/tree:$Name: $:$Id: TTreeFilePrefetch.cxx,v 1.8 2006/06/14 22:54:35 brun Exp $
+// @(#)root/tree:$Name: $:$Id: TTreeFilePrefetch.cxx,v 1.9 2006/06/15 07:59:19 brun Exp $
// Author: Rene Brun 04/06/2006
/*************************************************************************
@@ -47,6 +47,7 @@ TTreeFilePrefetch::TTreeFilePrefetch() : TFilePrefetch(),
fEntryMin(0),
fEntryMax(1),
fEntryNext(1),
+ fZipBytes(0),
fNbranches(0),
fBranches(0),
fIsLearning(kTRUE)
@@ -59,6 +60,7 @@ TTreeFilePrefetch::TTreeFilePrefetch(TTree *tree, Int_t buffersize) : TFilePrefe
fEntryMin(0),
fEntryMax(tree->GetEntries()),
fEntryNext(0),
+ fZipBytes(0),
fNbranches(0),
fBranches(0),
fIsLearning(kTRUE)
@@ -100,7 +102,6 @@ void TTreeFilePrefetch::AddBranch(TBranch *b)
//this function is called by TBranch::GetBasket
if (!fIsLearning) return;
- //if (b->GetListOfBranches()->GetEntries() > 0) return;
//Is branch already in the cache?
Bool_t isNew = kTRUE;
@@ -110,6 +111,7 @@ void TTreeFilePrefetch::AddBranch(TBranch *b)
if (isNew) {
fBranches[fNbranches] = b;
fNbranches++;
+ fZipBytes += b->GetZipBytes();
if (gDebug > 0) printf("Entry: %lld, registering branch: %s\n",b->GetTree()->GetReadEntry(),b->GetName());
}
}
@@ -120,7 +122,8 @@ void TTreeFilePrefetch::Clear(Option_t *)
//clear the cache (called by TChain::LoadTree)
Prefetch(0,0);
- fNbranches = 0;
+ fNbranches = 0;
+ fZipBytes = 0;
fIsLearning = kTRUE;
}
@@ -133,21 +136,16 @@ Bool_t TTreeFilePrefetch::FillBuffer()
if (fNbranches <= 0) return kFALSE;
TTree *tree = fBranches[0]->GetTree();
Long64_t entry = tree->GetReadEntry();
- if (fIsLearning && entry < fEntryNext) return kFALSE;
- //compute total size of the branches stored in cache
- Long64_t totbytes = 0;
- Int_t i;
- for (i=0;i<fNbranches;i++) {
- totbytes += fBranches[i]->GetZipBytes();
- }
+ if (entry < fEntryNext) return kFALSE;
+
//estimate number of entries that can fit in the cache
- fEntryNext = entry + tree->GetEntries()*fBufferSize/totbytes;
+ fEntryNext = entry + tree->GetEntries()*fBufferSize/fZipBytes;
if (fEntryNext > fEntryMax) fEntryNext = fEntryMax+1;
//clear cache buffer
TFilePrefetch::Prefetch(0,0);
//store baskets
- for (i=0;i<fNbranches;i++) {
+ for (Int_t i=0;i<fNbranches;i++) {
TBranch *b = fBranches[i];
Int_t nb = b->GetMaxBaskets();
Int_t *lbaskets = b->GetBasketBytes();
@@ -218,9 +216,10 @@ void TTreeFilePrefetch::SetEntryRange(Long64_t emin, Long64_t emax)
fEntryMax = emax;
Long64_t learn = Long64_t(fgLearnRatio*(fEntryMax-fEntryMin));
if (learn < 2) learn = 2;
- fEntryNext = emin + learn;
+ fEntryNext = emin + learn;
fIsLearning = kTRUE;
- fNbranches = 0;
+ fNbranches = 0;
+ fZipBytes = 0;
if (gDebug > 0) printf("SetEntryRange: fEntryMin=%lld, fEntryMax=%lld, fEntryNext=%lld\n",fEntryMin,fEntryMax,fEntryNext);
}
--
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