Specialization of TTreeCache for parallel Unzipping.

Fabrizio Furano (CERN) Aug 2009 Core TTree-related code borrowed from the previous version by Leandro Franco and Rene Brun

Parallel Unzipping

TTreeCache has been specialised in order to let additional threads free to unzip in advance its content. In this implementation we support up to 10 threads, but right now it makes more sense to limit their number to 1-2

The application reading data is carefully synchronized, in order to:

if the block it wants is not unzipped, it self-unzips it without waiting
if the block is being unzipped in parallel, it waits only for that unzip to finish
if the block has already been unzipped, it takes it

This is supposed to cancel a part of the unzipping latency, at the expenses of cpu time.

The default parameters are the same of the prev version, i.e. 20% of the TTreeCache cache size. To change it use TTreeCache::SetUnzipBufferSize(Long64_t bufferSize) where bufferSize must be passed in bytes.

Definition at line 41 of file TTreeCacheUnzip.h.

Public Types
enum	EParUnzipMode { kEnable, kDisable, kForce }

Public Types inherited from TTreeCache
enum	EPrefillType { kNoPrefill, kAllBranches }

Public Types inherited from TObject
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) }

enum	{ kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff }

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

Public Member Functions
	TTreeCacheUnzip ()

	TTreeCacheUnzip (TTree *tree, Int_t buffersize=0)
	Constructor. More...

virtual	~TTreeCacheUnzip ()
	Destructor. (in general called by the TFile destructor) More...

virtual Int_t	AddBranch (TBranch *b, Bool_t subbranches=kFALSE)
	Add a branch to the list of branches to be stored in the cache this function is called by TBranch::GetBasket Returns: More...

virtual Int_t	AddBranch (const char *branch, Bool_t subbranches=kFALSE)
	Add a branch to the list of branches to be stored in the cache this function is called by TBranch::GetBasket Returns: More...

Bool_t	FillBuffer ()
	Fill the cache buffer with the branches in the cache. More...

virtual Int_t	ReadBufferExt (char *buf, Long64_t pos, Int_t len, Int_t &loc)

void	SetEntryRange (Long64_t emin, Long64_t emax)
	Set the minimum and maximum entry number to be processed this information helps to optimize the number of baskets to read when prefetching the branch buffers. More...

virtual void	StopLearningPhase ()
	It's the same as TTreeCache::StopLearningPhase but we guarantee that we start the unzipping just after getting the buffers. More...

void	UpdateBranches (TTree *tree)
	update pointer to current Tree and recompute pointers to the branches in the cache More...

Bool_t	IsActiveThread ()
	This indicates if the thread is active in this moment... More...

Bool_t	IsQueueEmpty ()
	It says if the queue is empty... useful to see if we have to process it. More...

void	WaitUnzipStartSignal ()

void	SendUnzipStartSignal (Bool_t broadcast)
	This will send the signal corresponfing to the queue... More...

Int_t	GetRecordHeader (char *buf, Int_t maxbytes, Int_t &nbytes, Int_t &objlen, Int_t &keylen)
	Read the logical record header from the buffer buf. More...

virtual void	ResetCache ()
	This will delete the list of buffers that are in the unzipping cache and will reset certain values in the cache. More...

virtual Int_t	GetUnzipBuffer (char *buf, Long64_t pos, Int_t len, Bool_t free)
	We try to read a buffer that has already been unzipped Returns -1 in case of read failure, 0 in case it's not in the cache and n>0 in case read from cache (number of bytes copied). More...

virtual Int_t	SetBufferSize (Int_t buffersize)
	Change the underlying buffer size of the cache. More...

void	SetUnzipBufferSize (Long64_t bufferSize)
	Sets the size for the unzipping cache... More...

Int_t	UnzipBuffer (char *dest, char src)
	Unzips a ROOT specific buffer... More...

Int_t	UnzipCache (Int_t &startindex, Int_t &locbuffsz, char *&locbuff)
	This inflates all the buffers in the cache. More...

Int_t	GetNUnzip ()

Int_t	GetNFound ()

Int_t	GetNMissed ()

void	Print (Option_t *option="") const
	Print cache statistics. More...

Public Member Functions inherited from TTreeCache
	TTreeCache ()

	TTreeCache (TTree *tree, Int_t buffersize=0)
	Constructor. More...

virtual	~TTreeCache ()
	Destructor. (in general called by the TFile destructor) More...

virtual Int_t	DropBranch (TBranch *b, Bool_t subbranches=kFALSE)
	Remove a branch to the list of branches to be stored in the cache this function is called by TBranch::GetBasket. More...

virtual Int_t	DropBranch (const char *branch, Bool_t subbranches=kFALSE)
	Remove a branch to the list of branches to be stored in the cache this is to be used by user (thats why we pass the name of the branch). More...

virtual void	Disable ()

virtual void	Enable ()

const TObjArray *	GetCachedBranches () const

EPrefillType	GetConfiguredPrefillType () const
	Return the desired prefill type from the environment or resource variable. More...

Double_t	GetEfficiency () const
	Give the total efficiency of the cache... More...

Double_t	GetEfficiencyRel () const
	This will indicate a sort of relative efficiency... More...

virtual Int_t	GetEntryMin () const

virtual Int_t	GetEntryMax () const

virtual EPrefillType	GetLearnPrefill () const

TTree *	GetTree () const

Bool_t	IsAutoCreated () const

virtual Bool_t	IsEnabled () const

virtual Bool_t	IsLearning () const

virtual void	LearnPrefill ()
	Perform an initial prefetch, attempting to read as much of the learning phase baskets for all branches at once. More...

virtual Int_t	ReadBuffer (char *buf, Long64_t pos, Int_t len)
	Read buffer at position pos if the request is in the list of prefetched blocks read from fBuffer. More...

virtual Int_t	ReadBufferNormal (char *buf, Long64_t pos, Int_t len)
	Old method ReadBuffer before the addition of the prefetch mechanism. More...

virtual Int_t	ReadBufferPrefetch (char *buf, Long64_t pos, Int_t len)
	Used to read a chunk from a block previously fetched. More...

void	SetAutoCreated (Bool_t val)

virtual void	SetFile (TFile *file, TFile::ECacheAction action=TFile::kDisconnect)
	Overload to make sure that the object specific. More...

virtual void	SetLearnPrefill (EPrefillType type=kNoPrefill)
	Set whether the learning period is started with a prefilling of the cache and which type of prefilling is used. More...

void	StartLearningPhase ()
	The name should be enough to explain the method. More...

Public Member Functions inherited from TFileCacheRead
	TFileCacheRead ()

	TFileCacheRead (TFile file, Int_t buffersize, TObject tree=0)
	Creates a TFileCacheRead data structure. More...

virtual	~TFileCacheRead ()
	Destructor. More...

virtual void	AddNoCacheBytesRead (Long64_t len)

virtual void	AddNoCacheReadCalls (Int_t reads)

virtual void	Close (Option_t *option="")
	Close out any threads or asynchronous fetches used by the underlying implementation. More...

virtual Int_t	GetBufferSize () const

virtual Long64_t	GetBytesRead () const

virtual Long64_t	GetNoCacheBytesRead () const

virtual Long64_t	GetBytesReadExtra () const

TFile *	GetFile () const

Int_t	GetNseek () const

Int_t	GetNtot () const

virtual Int_t	GetReadCalls () const

virtual Int_t	GetNoCacheReadCalls () const

Long64_t	GetPrefetchedBlocks () const

virtual Bool_t	IsAsyncReading () const

virtual void	SetEnablePrefetching (Bool_t setPrefetching=kFALSE)
	Set the prefetching mode of this file. More...

virtual Bool_t	IsEnablePrefetching () const

virtual void	Prefetch (Long64_t pos, Int_t len)
	Add block of length len at position pos in the list of blocks to be prefetched. More...

virtual Int_t	ReadBufferExtNormal (char *buf, Long64_t pos, Int_t len, Int_t &loc)
	Base function for ReadBuffer. More...

virtual Int_t	ReadBufferExtPrefetch (char *buf, Long64_t pos, Int_t len, Int_t &loc)
	prefetch the first block More...

virtual void	SetSkipZip (Bool_t=kTRUE)

virtual void	Sort ()
	Sort buffers to be prefetched in increasing order of positions. More...

virtual void	SecondSort ()
	Sort buffers to be prefetched in increasing order of positions. More...

virtual void	SecondPrefetch (Long64_t, Int_t)

virtual TFilePrefetch *	GetPrefetchObj ()

virtual void	WaitFinishPrefetch ()

Public Member Functions inherited from TObject
	TObject ()

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

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

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

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

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

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

virtual void	Clear (Option_t *="")

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 abstract method. More...

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

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

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

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

virtual void	Dump () const
	Dump contents of object on stdout. 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 TObject *	FindObject (const char *name) const
	Must be redefined in derived classes. More...

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

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

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

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

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

virtual Option_t *	GetOption () const

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

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

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

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

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

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

virtual Bool_t	IsSortable () const

Bool_t	IsOnHeap () const

Bool_t	IsZombie () const

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

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

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

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

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...

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	UseCurrentStyle ()
	Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked. More...

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

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

void *	operator new (size_t sz)

void *	operator new[] (size_t sz)

void *	operator new (size_t sz, void *vp)

void *	operator new[] (size_t sz, void *vp)

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

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

void	ResetBit (UInt_t f)

Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

void	InvertBit (UInt_t f)

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

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

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

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

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

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...

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

Static Public Member Functions
static EParUnzipMode	GetParallelUnzip ()
	Static function that returns the parallel option (to indicate an additional thread) More...

static Bool_t	IsParallelUnzip ()
	Static function that tells wether the multithreading unzipping is activated. More...

static Int_t	SetParallelUnzip (TTreeCacheUnzip::EParUnzipMode option=TTreeCacheUnzip::kEnable)
	Static function that (de)activates multithreading unzipping. More...

static void	SetUnzipRelBufferSize (Float_t relbufferSize)
	static function: Sets the unzip relatibe buffer size More...

static void *	UnzipLoop (void *arg)
	This is a static function. More...

Static Public Member Functions inherited from TTreeCache
static Int_t	GetLearnEntries ()
	Static function returning the number of entries used to train the cache see SetLearnEntries. More...

static void	SetLearnEntries (Int_t n=10)
	Static function to set the number of entries to be used in learning mode The default value for n is 10. More...

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

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

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

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

Protected Attributes
TThread *	fUnzipThread [10]

Bool_t	fActiveThread

TCondition *	fUnzipStartCondition

TCondition *	fUnzipDoneCondition

Bool_t	fParallel

Bool_t	fAsyncReading

TMutex *	fMutexList

TMutex *	fIOMutex

Int_t	fCycle

Int_t	fLastReadPos

Int_t	fBlocksToGo

Int_t *	fUnzipLen

char **	fUnzipChunks
	[fNseek] Length of the unzipped buffers More...

Byte_t *	fUnzipStatus
	[fNseek] Individual unzipped chunks. Their summed size is kept under control. More...

Long64_t	fTotalUnzipBytes
	[fNSeek] For each blk, tells us if it's unzipped or pending More...

Int_t	fNseekMax
	The total sum of the currently unzipped blks. More...

Long64_t	fUnzipBufferSize
	fNseek can change so we need to know its max size More...

Int_t	fNUnzip

Int_t	fNFound
	number of blocks that were unzipped More...

Int_t	fNStalls
	number of blocks that were found in the cache More...

Int_t	fNMissed
	number of hits which caused a stall More...

std::queue< Int_t >	fActiveBlks
	number of blocks that were not found in the cache and were unzipped More...

Protected Attributes inherited from TTreeCache
Long64_t	fEntryMin

Long64_t	fEntryMax
	first entry in the cache More...

Long64_t	fEntryCurrent
	last entry in the cache More...

Long64_t	fEntryNext
	current lowest entry number in the cache More...

Int_t	fNbranches
	next entry number where cache must be filled More...

Int_t	fNReadOk
	Number of branches in the cache. More...

Int_t	fNReadMiss

Int_t	fNReadPref

TObjArray *	fBranches

TList *	fBrNames
	List of branches to be stored in the cache. More...

TTree *	fTree
	list of branch names in the cache More...

Bool_t	fIsLearning
	pointer to the current Tree More...

Bool_t	fIsManual
	true if cache is in learning mode More...

Bool_t	fFirstBuffer
	true if cache is StopLearningPhase was used More...

Bool_t	fOneTime
	true if first buffer is used for prefetching More...

Bool_t	fReverseRead
	used in the learning phase More...

Int_t	fFillTimes
	reading in reverse mode More...

Bool_t	fFirstTime
	how many times we can fill the current buffer More...

Long64_t	fFirstEntry
	save the fact that we processes the first entry More...

Bool_t	fReadDirectionSet
	save the value of the first entry More...

Bool_t	fEnabled
	read direction established More...

EPrefillType	fPrefillType
	cache enabled for cached reading More...

Bool_t	fAutoCreated

Protected Attributes inherited from TFileCacheRead
TFilePrefetch *	fPrefetch
	! Object that does the asynchronous reading in another thread More...

Int_t	fBufferSizeMin
	Original size of fBuffer. More...

Int_t	fBufferSize
	Allocated size of fBuffer (at a given time) More...

Int_t	fBufferLen
	Current buffer length (<= fBufferSize) More...

Long64_t	fBytesRead
	Number of bytes read for this cache. More...

Long64_t	fBytesReadExtra
	Number of extra bytes (overhead) read by the readahead buffer. More...

Int_t	fReadCalls
	Number of read calls for this cache. More...

Long64_t	fNoCacheBytesRead
	Number of bytes read by basket to fill cached tree. More...

Int_t	fNoCacheReadCalls
	Number of read calls by basket to fill cached tree. More...

Bool_t	fAsyncReading

Bool_t	fEnablePrefetching
	reading by prefetching asynchronously More...

Int_t	fNseek
	Number of blocks to be prefetched. More...

Int_t	fNtot
	Total size of prefetched blocks. More...

Int_t	fNb
	Number of long buffers. More...

Int_t	fSeekSize
	Allocated size of fSeek. More...

Long64_t *	fSeek
	[fNseek] Position on file of buffers to be prefetched More...

Long64_t *	fSeekSort
	[fNseek] Position on file of buffers to be prefetched (sorted) More...

Int_t *	fSeekIndex
	[fNseek] sorted index table of fSeek More...

Long64_t *	fPos
	[fNb] start of long buffers More...

Int_t *	fSeekLen
	[fNseek] Length of buffers to be prefetched More...

Int_t *	fSeekSortLen
	[fNseek] Length of buffers to be prefetched (sorted) More...

Int_t *	fSeekPos
	[fNseek] Position of sorted blocks in fBuffer More...

Int_t *	fLen
	[fNb] Length of long buffers More...

TFile *	fFile
	Pointer to file. More...

char *	fBuffer
	[fBufferSize] buffer of contiguous prefetched blocks More...

Bool_t	fIsSorted
	True if fSeek array is sorted. More...

Bool_t	fIsTransferred
	True when fBuffer contains something valid. More...

Long64_t	fPrefetchedBlocks
	Number of blocks prefetched. More...

Int_t	fBNseek

Int_t	fBNtot

Int_t	fBNb

Int_t	fBSeekSize

Long64_t *	fBSeek
	[fBNseek] More...

Long64_t *	fBSeekSort
	[fBNseek] More...

Int_t *	fBSeekIndex
	[fBNseek] More...

Long64_t *	fBPos
	[fBNb] More...

Int_t *	fBSeekLen
	[fBNseek] More...

Int_t *	fBSeekSortLen
	[fBNseek] More...

Int_t *	fBSeekPos
	[fBNseek] More...

Int_t *	fBLen
	[fBNb] More...

Bool_t	fBIsSorted

Bool_t	fBIsTransferred

Static Protected Attributes
static TTreeCacheUnzip::EParUnzipMode	fgParallel = TTreeCacheUnzip::kDisable

static Double_t	fgRelBuffSize = .5
	Max Size for the ready unzipped blocks (default is 2*fBufferSize) More...

Static Protected Attributes inherited from TTreeCache
static Int_t	fgLearnEntries = 100

Private Member Functions
	TTreeCacheUnzip (const TTreeCacheUnzip &)

TTreeCacheUnzip &	operator= (const TTreeCacheUnzip &)

void	Init ()
	Initialization procedure common to all the constructors. More...

Int_t	StartThreadUnzip (Int_t nthreads)
	The Thread is only a part of the TTreeCache but it is the part that waits for info in the queue and process it... More...

Int_t	StopThreadUnzip ()
	To stop the thread we only need to change the value of the variable fActiveThread to false and the loop will stop (of course, we will have) to do the cleaning after that. More...

Private Attributes
char *	fCompBuffer

Int_t	fCompBufferSize

Additional Inherited Members
Protected Member Functions inherited from TFileCacheRead
void	SetEnablePrefetchingImpl (Bool_t setPrefetching=kFALSE)
	TFileCacheRead implementation of SetEnablePrefetching. More...

Protected Member Functions inherited from TObject
void	MakeZombie ()

virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected). More...

#include <TTreeCacheUnzip.h>

Inheritance diagram for TTreeCacheUnzip:

[legend]

Member Enumeration Documentation

enum TTreeCacheUnzip::EParUnzipMode

Enumerator
kEnable
kDisable
kForce

Definition at line 45 of file TTreeCacheUnzip.h.

Constructor & Destructor Documentation

TTreeCacheUnzip::TTreeCacheUnzip ( const TTreeCacheUnzip & )

private

TTreeCacheUnzip::TTreeCacheUnzip ( )

TTreeCacheUnzip::TTreeCacheUnzip	(	TTree *	tree,
		Int_t	buffersize = `0`
	)

Constructor.

Definition at line 99 of file TTreeCacheUnzip.cxx.

TTreeCacheUnzip::~TTreeCacheUnzip ( )

virtual

Destructor. (in general called by the TFile destructor)

Definition at line 169 of file TTreeCacheUnzip.cxx.

Member Function Documentation

Int_t TTreeCacheUnzip::AddBranch	(	TBranch *	b,
		Bool_t	subbranches = `kFALSE`
	)

virtual

Add a branch to the list of branches to be stored in the cache this function is called by TBranch::GetBasket Returns:

0 branch added or already included
-1 on error

Reimplemented from TTreeCache.

Definition at line 195 of file TTreeCacheUnzip.cxx.

Int_t TTreeCacheUnzip::AddBranch	(	const char *	branch,
		Bool_t	subbranches = `kFALSE`
	)

virtual

Add a branch to the list of branches to be stored in the cache this function is called by TBranch::GetBasket Returns:

0 branch added or already included
-1 on error

Reimplemented from TTreeCache.

Definition at line 209 of file TTreeCacheUnzip.cxx.

Bool_t TTreeCacheUnzip::FillBuffer ( )

virtual

Fill the cache buffer with the branches in the cache.

Reimplemented from TTreeCache.

Definition at line 218 of file TTreeCacheUnzip.cxx.

Int_t TTreeCacheUnzip::GetNFound ( )

inline

Definition at line 131 of file TTreeCacheUnzip.h.

Int_t TTreeCacheUnzip::GetNMissed ( )

inline

Definition at line 132 of file TTreeCacheUnzip.h.

Int_t TTreeCacheUnzip::GetNUnzip ( )

inline

Definition at line 130 of file TTreeCacheUnzip.h.

TTreeCacheUnzip::EParUnzipMode TTreeCacheUnzip::GetParallelUnzip ( )

static

Static function that returns the parallel option (to indicate an additional thread)

Definition at line 370 of file TTreeCacheUnzip.cxx.

Int_t TTreeCacheUnzip::GetRecordHeader	(	char *	buf,
		Int_t	maxbytes,
		Int_t &	nbytes,
		Int_t &	objlen,
		Int_t &	keylen
	)

Read the logical record header from the buffer buf.

That must be the pointer tho the header part not the object by itself and must contain data of at least maxbytes Returns nread;

In output arguments:

nbytes : number of bytes in record if negative, this is a deleted record if 0, cannot read record, wrong value of argument first
objlen : uncompressed object size
keylen : length of logical record header

Note that the arguments objlen and keylen are returned only if maxbytes >=16 Note: This was adapted from TFile... so some things dont apply

Definition at line 610 of file TTreeCacheUnzip.cxx.

Referenced by UnzipBuffer(), and UnzipCache().

Int_t TTreeCacheUnzip::GetUnzipBuffer	(	char **	buf,
		Long64_t	pos,
		Int_t	len,
		Bool_t *	free
	)

virtual

We try to read a buffer that has already been unzipped Returns -1 in case of read failure, 0 in case it's not in the cache and n>0 in case read from cache (number of bytes copied).

pos and len are the original values as were passed to ReadBuffer but instead we will return the inflated buffer. Note!! : If *buf == 0 we will allocate the buffer and it will be the responsability of the caller to free it... it is useful for example to pass it to the creator of TBuffer

Reimplemented from TFileCacheRead.

Definition at line 707 of file TTreeCacheUnzip.cxx.

void TTreeCacheUnzip::Init ( void )

private

Initialization procedure common to all the constructors.

Definition at line 122 of file TTreeCacheUnzip.cxx.

Referenced by TTreeCacheUnzip().

Bool_t TTreeCacheUnzip::IsActiveThread ( )

This indicates if the thread is active in this moment...

this variable is very important because if we change it from true to false the thread will stop... ( see StopThreadTreeCacheUnzip() )

Definition at line 391 of file TTreeCacheUnzip.cxx.

Referenced by GetUnzipBuffer(), UnzipCache(), UnzipLoop(), and ~TTreeCacheUnzip().

Bool_t TTreeCacheUnzip::IsParallelUnzip ( )

static

Static function that tells wether the multithreading unzipping is activated.

Definition at line 378 of file TTreeCacheUnzip.cxx.

Referenced by TTree::SetCacheSizeAux().

Bool_t TTreeCacheUnzip::IsQueueEmpty ( )

It says if the queue is empty... useful to see if we have to process it.

Definition at line 401 of file TTreeCacheUnzip.cxx.

TTreeCacheUnzip& TTreeCacheUnzip::operator= ( const TTreeCacheUnzip & )

private

void TTreeCacheUnzip::Print ( Option_t * option = "" ) const

virtual

Print cache statistics.

Like:

******TreeCache statistics for file: cms2.root ******
Number of branches in the cache ...: 1093
Cache Efficiency ..................: 0.997372
Cache Efficiency Rel...............: 1.000000
Learn entries......................: 100
Reading............................: 72761843 bytes in 7 transactions
Readahead..........................: 256000 bytes with overhead = 0 bytes
Average transaction................: 10394.549000 Kbytes
Number of blocks in current cache..: 210, total size: 6280352

if option = "a" the list of blocks in the cache is printed see also class TTreePerfStats.
if option contains 'cachedbranches', the list of branches being cached is printed.

Reimplemented from TTreeCache.

Definition at line 1245 of file TTreeCacheUnzip.cxx.

Int_t TTreeCacheUnzip::ReadBufferExt	(	char *	buf,
		Long64_t	pos,
		Int_t	len,
		Int_t &	loc
	)

virtual

Reimplemented from TFileCacheRead.

Definition at line 1259 of file TTreeCacheUnzip.cxx.

Referenced by GetUnzipBuffer(), and UnzipCache().

void TTreeCacheUnzip::ResetCache ( )

virtual

This will delete the list of buffers that are in the unzipping cache and will reset certain values in the cache.

This name is ambiguos because the method doesn't reset the whole cache, only the part related to the unzipping Note: This method is completely different from TTreeCache::ResetCache(), in that method we were cleaning the prefetching buffer while here we delete the information about the unzipped buffers

Reimplemented from TTreeCache.

Definition at line 642 of file TTreeCacheUnzip.cxx.

Referenced by FillBuffer(), SetBufferSize(), and ~TTreeCacheUnzip().

void TTreeCacheUnzip::SendUnzipStartSignal ( Bool_t broadcast )

This will send the signal corresponfing to the queue...

normally used when we want to start processing the list of buffers.

Definition at line 423 of file TTreeCacheUnzip.cxx.

Referenced by GetUnzipBuffer(), ResetCache(), and StopThreadUnzip().

Int_t TTreeCacheUnzip::SetBufferSize ( Int_t buffersize )

virtual

Change the underlying buffer size of the cache.

Returns:

0 if the buffer content is still available
1 if some or all of the buffer content has been made unavailable
-1 on error

Reimplemented from TTreeCache.

Definition at line 313 of file TTreeCacheUnzip.cxx.

void TTreeCacheUnzip::SetEntryRange	(	Long64_t	emin,
		Long64_t	emax
	)

virtual

Set the minimum and maximum entry number to be processed this information helps to optimize the number of baskets to read when prefetching the branch buffers.

Reimplemented from TTreeCache.

Definition at line 331 of file TTreeCacheUnzip.cxx.

Int_t TTreeCacheUnzip::SetParallelUnzip ( TTreeCacheUnzip::EParUnzipMode option = TTreeCacheUnzip::kEnable )

static

Static function that (de)activates multithreading unzipping.

The possible options are:

kEnable Enable it, which causes an automatic detection and launches the additional thread if the number of cores in the machine is greater than one
kDisable Disable will not activate the additional thread.
kForce Force will start the additional thread even if there is only one core. the default will be taken as kEnable.

Returns 0 if there was an error, 1 otherwise.

Definition at line 446 of file TTreeCacheUnzip.cxx.

Referenced by TTree::SetParallelUnzip(), and TEventIterTree::TEventIterTree().

void TTreeCacheUnzip::SetUnzipBufferSize ( Long64_t bufferSize )

Sets the size for the unzipping cache...

by default it should be two times the size of the prefetching cache

Definition at line 930 of file TTreeCacheUnzip.cxx.

void TTreeCacheUnzip::SetUnzipRelBufferSize ( Float_t relbufferSize )

static

static function: Sets the unzip relatibe buffer size

Definition at line 921 of file TTreeCacheUnzip.cxx.

Referenced by TTree::SetParallelUnzip().

Int_t TTreeCacheUnzip::StartThreadUnzip ( Int_t nthreads )

private

The Thread is only a part of the TTreeCache but it is the part that waits for info in the queue and process it...

unfortunatly, a Thread is not an object an we have to deal with it in the old C-Style way Returns 0 if the thread was initialized or 1 if it was already running

Definition at line 467 of file TTreeCacheUnzip.cxx.

Referenced by Init().

void TTreeCacheUnzip::StopLearningPhase ( )

virtual

It's the same as TTreeCache::StopLearningPhase but we guarantee that we start the unzipping just after getting the buffers.

Reimplemented from TTreeCache.

Definition at line 342 of file TTreeCacheUnzip.cxx.

Int_t TTreeCacheUnzip::StopThreadUnzip ( )

private

To stop the thread we only need to change the value of the variable fActiveThread to false and the loop will stop (of course, we will have) to do the cleaning after that.

Note: The syncronization part is important here or we will try to delete teh object while it's still processing the queue

Definition at line 510 of file TTreeCacheUnzip.cxx.

Referenced by ~TTreeCacheUnzip().

Int_t TTreeCacheUnzip::UnzipBuffer	(	char **	dest,
		char *	src
	)

Unzips a ROOT specific buffer...

by reading the header at the beginning. returns the size of the inflated buffer or -1 if error Note!! : If *dest == 0 we will allocate the buffer and it will be the responsability of the caller to free it... it is useful for example to pass it to the creator of TBuffer src is the original buffer with the record (header+compressed data) *dest is the inflated buffer (including the header)

Definition at line 946 of file TTreeCacheUnzip.cxx.

Referenced by GetUnzipBuffer(), and UnzipCache().

Int_t TTreeCacheUnzip::UnzipCache	(	Int_t &	startindex,
		Int_t &	locbuffsz,
		char *&	locbuff
	)

This inflates all the buffers in the cache.

. passing the data to a new buffer that will only wait there to be read... We can not inflate all the buffers in the cache so we will try to do it until the cache gets full... there is a member called fUnzipBufferSize which will tell us the max size we can allocate for this cache.

note that we will unzip in the order they were put into the cache not the order of the transference so it has to be read in that order or the pre-unzipping will be useless.

startindex is used as start index to check for blks to be unzipped

returns 0 in normal conditions or -1 if error, 1 if it would like to sleep

This func is supposed to compete among an indefinite number of threads to get a chunk to inflate in order to accommodate multiple unzippers Since everything is so async, we cannot use a fixed buffer, we are forced to keep the individual chunks as separate blocks, whose summed size does not exceed the maximum allowed. The pointers are kept globally in the array fUnzipChunks

Definition at line 1059 of file TTreeCacheUnzip.cxx.

Referenced by UnzipLoop().

void * TTreeCacheUnzip::UnzipLoop ( void * arg )

static

This is a static function.

This is the call that will be executed in the Thread generated by StartThreadTreeCacheUnzip... what we want to do is to inflate the next series of buffers leaving them in the second cache.

Returns 0 when it finishes

Definition at line 539 of file TTreeCacheUnzip.cxx.

Referenced by StartThreadUnzip().

void TTreeCacheUnzip::UpdateBranches ( TTree * tree )

virtual

update pointer to current Tree and recompute pointers to the branches in the cache

Reimplemented from TTreeCache.

Definition at line 353 of file TTreeCacheUnzip.cxx.

void TTreeCacheUnzip::WaitUnzipStartSignal ( )

Definition at line 411 of file TTreeCacheUnzip.cxx.

Referenced by UnzipLoop().