A cache when reading files over the network.

A caching system to speed up network I/O, i.e. when there is no operating system caching support (like the buffer cache for local disk I/O). The cache makes sure that every I/O is done with a (large) fixed length buffer thereby avoiding many small I/O's. Currently the read cache system is used by the classes TNetFile, TXNetFile and TWebFile (via TFile::ReadBuffers()). When processing TTree, TChain, a specialized class TTreeCache that derives from this class is automatically created.

Definition at line 22 of file TFileCacheRead.h.

Public Member Functions
	TFileCacheRead ()
	Default Constructor.

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

	~TFileCacheRead () override
	Destructor.

virtual Int_t	AddBranch (const char *, Bool_t=kFALSE)

virtual Int_t	AddBranch (TBranch *, Bool_t=kFALSE)

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.

virtual Int_t	GetBufferSize () const

virtual Long64_t	GetBytesRead () const

virtual Long64_t	GetBytesReadExtra () const

TFile *	GetFile () const

virtual Long64_t	GetNoCacheBytesRead () const

virtual Int_t	GetNoCacheReadCalls () const

Int_t	GetNseek () const

Int_t	GetNtot () const

Long64_t	GetPrefetchedBlocks () const

virtual TFilePrefetch *	GetPrefetchObj ()

virtual Int_t	GetReadCalls () const

virtual Int_t	GetUnzipBuffer (char *, Long64_t, Int_t, Bool_t )

TClass *	IsA () const override

virtual Bool_t	IsAsyncReading () const

virtual Bool_t	IsEnablePrefetching () const

virtual Bool_t	IsLearning () const

virtual Int_t	LearnBranch (TBranch *, Bool_t=kFALSE)

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.

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

virtual Int_t	ReadBuffer (char *buf, Long64_t pos, Int_t len)
	Read buffer at position pos.

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

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

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

virtual void	SecondPrefetch (Long64_t, Int_t)

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

virtual Int_t	SetBufferSize (Int_t buffersize)
	Sets the buffer size.

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

virtual void	SetFile (TFile *file, TFile::ECacheAction action=TFile::kDisconnect)
	Set the file using this cache and reset the current blocks (if any).

virtual void	SetSkipZip (Bool_t=kTRUE)

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

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

void	StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)

virtual void	WaitFinishPrefetch ()

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 void	Clear (Option_t *="")

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).

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification (the base implementation is no-op).

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 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 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
void	SetEnablePrefetchingImpl (Bool_t setPrefetching=kFALSE)
	TFileCacheRead implementation of SetEnablePrefetching.

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
Bool_t	fAsyncReading

Bool_t	fBIsSorted

Bool_t	fBIsTransferred

Int_t *	fBLen
	[fBNb]

Int_t	fBNb

Int_t	fBNseek

Int_t	fBNtot

Long64_t *	fBPos
	[fBNb]

Long64_t *	fBSeek
	[fBNseek]

Int_t *	fBSeekIndex
	[fBNseek]

Int_t *	fBSeekLen
	[fBNseek]

Int_t *	fBSeekPos
	[fBNseek]

Int_t	fBSeekSize

Long64_t *	fBSeekSort
	[fBNseek]

Int_t *	fBSeekSortLen
	[fBNseek]

char *	fBuffer
	[fBufferSize] buffer of contiguous prefetched blocks

Int_t	fBufferLen
	Current buffer length (<= fBufferSize)

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

Int_t	fBufferSizeMin
	Original size of fBuffer.

Long64_t	fBytesRead
	Number of bytes read for this cache.

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

Bool_t	fEnablePrefetching
	reading by prefetching asynchronously

TFile *	fFile
	Pointer to file.

Bool_t	fIsSorted
	True if fSeek array is sorted.

Bool_t	fIsTransferred
	True when fBuffer contains something valid.

Int_t *	fLen
	[fNb] Length of long buffers

Int_t	fNb
	Number of long buffers.

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

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

Int_t	fNseek
	Number of blocks to be prefetched.

Int_t	fNtot
	Total size of prefetched blocks.

Long64_t *	fPos
	[fNb] start of long buffers

TFilePrefetch *	fPrefetch
	! Object that does the asynchronous reading in another thread

Long64_t	fPrefetchedBlocks
	Number of blocks prefetched.

Int_t	fReadCalls
	Number of read calls for this cache.

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

Int_t *	fSeekIndex
	[fNseek] sorted index table of fSeek

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

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

Int_t	fSeekSize
	Allocated size of fSeek.

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

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

Private Member Functions
	TFileCacheRead (const TFileCacheRead &)=delete

TFileCacheRead &	operator= (const TFileCacheRead &)=delete

Additional Inherited Members
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 )) }

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

#include <TFileCacheRead.h>

Inheritance diagram for TFileCacheRead:

[legend]

Constructor & Destructor Documentation

◆ TFileCacheRead() [1/3]

TFileCacheRead::TFileCacheRead ( const TFileCacheRead & )

privatedelete

◆ TFileCacheRead() [2/3]

TFileCacheRead::TFileCacheRead ( )

Default Constructor.

Definition at line 40 of file TFileCacheRead.cxx.

◆ TFileCacheRead() [3/3]

TFileCacheRead::TFileCacheRead	(	TFile *	file,
		Int_t	buffersize,
		TObject *	tree = `nullptr`
	)

Creates a TFileCacheRead data structure.

Definition at line 92 of file TFileCacheRead.cxx.

◆ ~TFileCacheRead()

TFileCacheRead::~TFileCacheRead ( )

override

Destructor.

Definition at line 159 of file TFileCacheRead.cxx.

Member Function Documentation

◆ AddBranch() [1/2]

virtual Int_t TFileCacheRead::AddBranch	(	const char *	,
		Bool_t	= `kFALSE`
	)

inlinevirtual

Reimplemented in TTreeCache, and TTreeCacheUnzip.

Definition at line 84 of file TFileCacheRead.h.

◆ AddBranch() [2/2]

virtual Int_t TFileCacheRead::AddBranch	(	TBranch *	,
		Bool_t	= `kFALSE`
	)

inlinevirtual

Reimplemented in TTreeCacheUnzip, and TTreeCache.

Definition at line 83 of file TFileCacheRead.h.

◆ AddNoCacheBytesRead()

virtual void TFileCacheRead::AddNoCacheBytesRead ( Long64_t len )

inlinevirtual

Definition at line 85 of file TFileCacheRead.h.

◆ AddNoCacheReadCalls()

virtual void TFileCacheRead::AddNoCacheReadCalls ( Int_t reads )

inlinevirtual

Definition at line 86 of file TFileCacheRead.h.

◆ Class()

static TClass * TFileCacheRead::Class ( )

static

Returns: TClass describing this class

◆ Class_Name()

static const char * TFileCacheRead::Class_Name ( )

static

Returns: Name of this class

◆ Class_Version()

static constexpr Version_t TFileCacheRead::Class_Version ( )

inlinestaticconstexpr

Returns: Version of this class

Definition at line 119 of file TFileCacheRead.h.

◆ Close()

void TFileCacheRead::Close ( Option_t * option = "" )

virtual

Close out any threads or asynchronous fetches used by the underlying implementation.

This is called by TFile::Close to prevent usage of the file handles after the closing of the file.

Definition at line 188 of file TFileCacheRead.cxx.

◆ DeclFileName()

static const char * TFileCacheRead::DeclFileName ( )

inlinestatic

Returns: Name of the file containing the class declaration

Definition at line 119 of file TFileCacheRead.h.

◆ GetBufferSize()

virtual Int_t TFileCacheRead::GetBufferSize ( ) const

inlinevirtual

Definition at line 88 of file TFileCacheRead.h.

◆ GetBytesRead()

virtual Long64_t TFileCacheRead::GetBytesRead ( ) const

inlinevirtual

Definition at line 89 of file TFileCacheRead.h.

◆ GetBytesReadExtra()

virtual Long64_t TFileCacheRead::GetBytesReadExtra ( ) const

inlinevirtual

Definition at line 91 of file TFileCacheRead.h.

◆ GetFile()

TFile * TFileCacheRead::GetFile ( ) const

inline

Definition at line 92 of file TFileCacheRead.h.

◆ GetNoCacheBytesRead()

virtual Long64_t TFileCacheRead::GetNoCacheBytesRead ( ) const

inlinevirtual

Definition at line 90 of file TFileCacheRead.h.

◆ GetNoCacheReadCalls()

virtual Int_t TFileCacheRead::GetNoCacheReadCalls ( ) const

inlinevirtual

Definition at line 96 of file TFileCacheRead.h.

◆ GetNseek()

Int_t TFileCacheRead::GetNseek ( ) const

inline

Definition at line 93 of file TFileCacheRead.h.

◆ GetNtot()

Int_t TFileCacheRead::GetNtot ( ) const

inline

Definition at line 94 of file TFileCacheRead.h.

◆ GetPrefetchedBlocks()

Long64_t TFileCacheRead::GetPrefetchedBlocks ( ) const

inline

Definition at line 98 of file TFileCacheRead.h.

◆ GetPrefetchObj()

TFilePrefetch * TFileCacheRead::GetPrefetchObj ( )

virtual

Definition at line 683 of file TFileCacheRead.cxx.

◆ GetReadCalls()

virtual Int_t TFileCacheRead::GetReadCalls ( ) const

inlinevirtual

Definition at line 95 of file TFileCacheRead.h.

◆ GetUnzipBuffer()

virtual Int_t TFileCacheRead::GetUnzipBuffer	(	char **	,
		Long64_t	,
		Int_t	,
		Bool_t *
	)

inlinevirtual

Reimplemented in TTreeCacheUnzip.

Definition at line 97 of file TFileCacheRead.h.

◆ IsA()

TClass * TFileCacheRead::IsA ( ) const

inlineoverridevirtual

Returns: TClass describing current object

Reimplemented from TObject.

Reimplemented in TTreeCache, and TTreeCacheUnzip.

Definition at line 119 of file TFileCacheRead.h.

◆ IsAsyncReading()

virtual Bool_t TFileCacheRead::IsAsyncReading ( ) const

inlinevirtual

Definition at line 99 of file TFileCacheRead.h.

◆ IsEnablePrefetching()

virtual Bool_t TFileCacheRead::IsEnablePrefetching ( ) const

inlinevirtual

Definition at line 101 of file TFileCacheRead.h.

◆ IsLearning()

virtual Bool_t TFileCacheRead::IsLearning ( ) const

inlinevirtual

Reimplemented in TTreeCache.

Definition at line 102 of file TFileCacheRead.h.

◆ LearnBranch()

virtual Int_t TFileCacheRead::LearnBranch	(	TBranch *	,
		Bool_t	= `kFALSE`
	)

inlinevirtual

Reimplemented in TTreeCache.

Definition at line 103 of file TFileCacheRead.h.

◆ operator=()

TFileCacheRead & TFileCacheRead::operator= ( const TFileCacheRead & )

privatedelete

◆ Prefetch()

void TFileCacheRead::Prefetch	(	Long64_t	pos,
		Int_t	len
	)

virtual

Add block of length len at position pos in the list of blocks to be prefetched.

If pos <= 0 the current blocks (if any) are reset.

Definition at line 201 of file TFileCacheRead.cxx.

◆ Print()

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

overridevirtual

Print cache statistics.

The format is: ******TreeCache statistics for file: cms2.root ****** 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 NB: this function is automatically called by TTreeCache::Print

Reimplemented from TObject.

Reimplemented in TTreeCache, and TTreeCacheUnzip.

Definition at line 325 of file TFileCacheRead.cxx.

◆ ReadBuffer()

Int_t TFileCacheRead::ReadBuffer	(	char *	buf,
		Long64_t	pos,
		Int_t	len
	)

virtual

Read buffer at position pos.

If pos is in the list of prefetched blocks read from fBuffer, otherwise need to make a normal read from file. Returns -1 in case of read error, 0 in case not in cache, 1 in case read from cache.

Reimplemented in TTreeCache.

Definition at line 363 of file TFileCacheRead.cxx.

◆ ReadBufferExt()

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

virtual

Reimplemented in TTreeCacheUnzip.

Definition at line 381 of file TFileCacheRead.cxx.

◆ ReadBufferExtNormal()

Int_t TFileCacheRead::ReadBufferExtNormal	(	char *	buf,
		Long64_t	pos,
		Int_t	len,
		Int_t &	loc
	)

virtual

Base function for ReadBuffer.

Also gives out the position of the block in the internal buffer. This helps TTreeCacheUnzip to avoid doing twice the binary search.

Definition at line 453 of file TFileCacheRead.cxx.

◆ ReadBufferExtPrefetch()

Int_t TFileCacheRead::ReadBufferExtPrefetch	(	char *	buf,
		Long64_t	pos,
		Int_t	len,
		Int_t &	loc
	)

virtual

prefetch the first block

Definition at line 393 of file TFileCacheRead.cxx.

◆ SecondPrefetch()

void TFileCacheRead::SecondPrefetch	(	Long64_t	pos,
		Int_t	len
	)

virtual

Definition at line 258 of file TFileCacheRead.cxx.

◆ SecondSort()

void TFileCacheRead::SecondSort ( )

virtual

Sort buffers to be prefetched in increasing order of positions.

Merge consecutive blocks if necessary.

Definition at line 629 of file TFileCacheRead.cxx.

◆ SetBufferSize()

Int_t TFileCacheRead::SetBufferSize ( Int_t buffersize )

virtual

Sets the buffer size.

If the current prefetch list is too large to fit in the new buffer some or all of the prefetch blocks are dropped. The requested buffersize must be greater than zero. Return values:

0 if the prefetch block lists remain unchanged
1 if some or all blocks have been removed from the prefetch list
-1 on error

Reimplemented in TTreeCache, and TTreeCacheUnzip.

Definition at line 709 of file TFileCacheRead.cxx.

◆ SetEnablePrefetching()

void TFileCacheRead::SetEnablePrefetching ( Bool_t setPrefetching = kFALSE )

virtual

Set the prefetching mode of this file.

If 'setPrefetching', enable the asynchronous prefetching (using TFilePrefetch) and if the gEnv and rootrc variable Cache.Directory is set, also enable the local caching of the prefetched blocks. if 'setPrefetching', the old prefetcher is enabled is the gEnv and rootrc variable is TFile.AsyncReading

Definition at line 771 of file TFileCacheRead.cxx.

◆ SetEnablePrefetchingImpl()

void TFileCacheRead::SetEnablePrefetchingImpl ( Bool_t setPrefetching = kFALSE )

protected

TFileCacheRead implementation of SetEnablePrefetching.

This function is called from the constructor and should not be virtual.

Definition at line 781 of file TFileCacheRead.cxx.

◆ SetFile()

void TFileCacheRead::SetFile	(	TFile *	file,
		TFile::ECacheAction	action = `TFile::kDisconnect`
	)

virtual

Set the file using this cache and reset the current blocks (if any).

Reimplemented in TTreeCache.

Definition at line 544 of file TFileCacheRead.cxx.

◆ SetSkipZip()

virtual void TFileCacheRead::SetSkipZip ( Bool_t = kTRUE )

inlinevirtual

Definition at line 112 of file TFileCacheRead.h.

◆ Sort()

void TFileCacheRead::Sort ( )

virtual

Sort buffers to be prefetched in increasing order of positions.

Merge consecutive blocks if necessary.

Definition at line 571 of file TFileCacheRead.cxx.

◆ Streamer()

void TFileCacheRead::Streamer ( TBuffer & R__b )

overridevirtual

Stream an object of class TObject.

Reimplemented from TObject.

Reimplemented in TTreeCache, and TTreeCacheUnzip.

◆ StreamerNVirtual()

void TFileCacheRead::StreamerNVirtual ( TBuffer & ClassDef_StreamerNVirtual_b )

inline

Definition at line 119 of file TFileCacheRead.h.

◆ WaitFinishPrefetch()

void TFileCacheRead::WaitFinishPrefetch ( )

virtual

Definition at line 690 of file TFileCacheRead.cxx.

Member Data Documentation

◆ fAsyncReading

Bool_t TFileCacheRead::fAsyncReading

protected

Definition at line 36 of file TFileCacheRead.h.

◆ fBIsSorted

Bool_t TFileCacheRead::fBIsSorted

protected

Definition at line 70 of file TFileCacheRead.h.

◆ fBIsTransferred

Bool_t TFileCacheRead::fBIsTransferred

protected

Definition at line 71 of file TFileCacheRead.h.

◆ fBLen

Int_t* TFileCacheRead::fBLen

protected

[fBNb]

Definition at line 69 of file TFileCacheRead.h.

◆ fBNb

Int_t TFileCacheRead::fBNb

protected

Definition at line 60 of file TFileCacheRead.h.

◆ fBNseek

Int_t TFileCacheRead::fBNseek

protected

Definition at line 58 of file TFileCacheRead.h.

◆ fBNtot

Int_t TFileCacheRead::fBNtot

protected

Definition at line 59 of file TFileCacheRead.h.

◆ fBPos

Long64_t* TFileCacheRead::fBPos

protected

[fBNb]

Definition at line 65 of file TFileCacheRead.h.

◆ fBSeek

Long64_t* TFileCacheRead::fBSeek

protected

[fBNseek]

Definition at line 62 of file TFileCacheRead.h.

◆ fBSeekIndex

Int_t* TFileCacheRead::fBSeekIndex

protected

[fBNseek]

Definition at line 64 of file TFileCacheRead.h.

◆ fBSeekLen

Int_t* TFileCacheRead::fBSeekLen

protected

[fBNseek]

Definition at line 66 of file TFileCacheRead.h.

◆ fBSeekPos

Int_t* TFileCacheRead::fBSeekPos

protected

[fBNseek]

Definition at line 68 of file TFileCacheRead.h.

◆ fBSeekSize

Int_t TFileCacheRead::fBSeekSize

protected

Definition at line 61 of file TFileCacheRead.h.

◆ fBSeekSort

Long64_t* TFileCacheRead::fBSeekSort

protected

[fBNseek]

Definition at line 63 of file TFileCacheRead.h.

◆ fBSeekSortLen

Int_t* TFileCacheRead::fBSeekSortLen

protected

[fBNseek]

Definition at line 67 of file TFileCacheRead.h.

◆ fBuffer

char* TFileCacheRead::fBuffer

protected

[fBufferSize] buffer of contiguous prefetched blocks

Definition at line 52 of file TFileCacheRead.h.

◆ fBufferLen

Int_t TFileCacheRead::fBufferLen

protected

Current buffer length (<= fBufferSize)

Definition at line 28 of file TFileCacheRead.h.

◆ fBufferSize

Int_t TFileCacheRead::fBufferSize

protected

Allocated size of fBuffer (at a given time)

Definition at line 27 of file TFileCacheRead.h.

◆ fBufferSizeMin

Int_t TFileCacheRead::fBufferSizeMin

protected

Original size of fBuffer.

Definition at line 26 of file TFileCacheRead.h.

◆ fBytesRead

Long64_t TFileCacheRead::fBytesRead

protected

Number of bytes read for this cache.

Definition at line 30 of file TFileCacheRead.h.

◆ fBytesReadExtra

Long64_t TFileCacheRead::fBytesReadExtra

protected

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

Definition at line 31 of file TFileCacheRead.h.

◆ fEnablePrefetching

Bool_t TFileCacheRead::fEnablePrefetching

protected

reading by prefetching asynchronously

Definition at line 37 of file TFileCacheRead.h.

◆ fFile

TFile* TFileCacheRead::fFile

protected

Pointer to file.

Definition at line 51 of file TFileCacheRead.h.

◆ fIsSorted

Bool_t TFileCacheRead::fIsSorted

protected

True if fSeek array is sorted.

Definition at line 53 of file TFileCacheRead.h.

◆ fIsTransferred

Bool_t TFileCacheRead::fIsTransferred

protected

True when fBuffer contains something valid.

Definition at line 54 of file TFileCacheRead.h.

◆ fLen

Int_t* TFileCacheRead::fLen

protected

[fNb] Length of long buffers

Definition at line 50 of file TFileCacheRead.h.

◆ fNb

Int_t TFileCacheRead::fNb

protected

Number of long buffers.

Definition at line 41 of file TFileCacheRead.h.

◆ fNoCacheBytesRead

Long64_t TFileCacheRead::fNoCacheBytesRead

protected

Number of bytes read by basket to fill cached tree.

Definition at line 33 of file TFileCacheRead.h.

◆ fNoCacheReadCalls

Int_t TFileCacheRead::fNoCacheReadCalls

protected

Number of read calls by basket to fill cached tree.

Definition at line 34 of file TFileCacheRead.h.

◆ fNseek

Int_t TFileCacheRead::fNseek

protected

Number of blocks to be prefetched.

Definition at line 39 of file TFileCacheRead.h.

◆ fNtot

Int_t TFileCacheRead::fNtot

protected

Total size of prefetched blocks.

Definition at line 40 of file TFileCacheRead.h.

◆ fPos

Long64_t* TFileCacheRead::fPos

protected

[fNb] start of long buffers

Definition at line 46 of file TFileCacheRead.h.

◆ fPrefetch

TFilePrefetch* TFileCacheRead::fPrefetch

protected

! Object that does the asynchronous reading in another thread

Definition at line 25 of file TFileCacheRead.h.

◆ fPrefetchedBlocks

Long64_t TFileCacheRead::fPrefetchedBlocks

protected

Number of blocks prefetched.

Definition at line 55 of file TFileCacheRead.h.

◆ fReadCalls

Int_t TFileCacheRead::fReadCalls

protected

Number of read calls for this cache.

Definition at line 32 of file TFileCacheRead.h.

◆ fSeek

Long64_t* TFileCacheRead::fSeek

protected

[fNseek] Position on file of buffers to be prefetched

Definition at line 43 of file TFileCacheRead.h.

◆ fSeekIndex

Int_t* TFileCacheRead::fSeekIndex

protected

[fNseek] sorted index table of fSeek

Definition at line 45 of file TFileCacheRead.h.

◆ fSeekLen

Int_t* TFileCacheRead::fSeekLen

protected

[fNseek] Length of buffers to be prefetched

Definition at line 47 of file TFileCacheRead.h.

◆ fSeekPos

Int_t* TFileCacheRead::fSeekPos

protected

[fNseek] Position of sorted blocks in fBuffer

Definition at line 49 of file TFileCacheRead.h.

◆ fSeekSize

Int_t TFileCacheRead::fSeekSize

protected

Allocated size of fSeek.

Definition at line 42 of file TFileCacheRead.h.

◆ fSeekSort

Long64_t* TFileCacheRead::fSeekSort

protected

[fNseek] Position on file of buffers to be prefetched (sorted)

Definition at line 44 of file TFileCacheRead.h.

◆ fSeekSortLen

Int_t* TFileCacheRead::fSeekSortLen

protected

[fNseek] Length of buffers to be prefetched (sorted)

Definition at line 48 of file TFileCacheRead.h.

Libraries for TFileCacheRead:

[legend]

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

io/io/inc/TFileCacheRead.h
io/io/src/TFileCacheRead.cxx

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

◆ TFileCacheRead() [1/3]

◆ TFileCacheRead() [2/3]

◆ TFileCacheRead() [3/3]

◆ ~TFileCacheRead()

Member Function Documentation

◆ AddBranch() [1/2]

◆ AddBranch() [2/2]

◆ AddNoCacheBytesRead()

◆ AddNoCacheReadCalls()

◆ Class()

◆ Class_Name()

◆ Class_Version()

◆ Close()

◆ DeclFileName()

◆ GetBufferSize()

◆ GetBytesRead()

◆ GetBytesReadExtra()

◆ GetFile()

◆ GetNoCacheBytesRead()

◆ GetNoCacheReadCalls()

◆ GetNseek()

◆ GetNtot()

◆ GetPrefetchedBlocks()

◆ GetPrefetchObj()

◆ GetReadCalls()

◆ GetUnzipBuffer()

◆ IsA()

◆ IsAsyncReading()

◆ IsEnablePrefetching()

◆ IsLearning()

◆ LearnBranch()

◆ operator=()

◆ Prefetch()

◆ Print()

◆ ReadBuffer()

◆ ReadBufferExt()

◆ ReadBufferExtNormal()

◆ ReadBufferExtPrefetch()

◆ SecondPrefetch()

◆ SecondSort()

◆ SetBufferSize()

◆ SetEnablePrefetching()

◆ SetEnablePrefetchingImpl()

◆ SetFile()

◆ SetSkipZip()

◆ Sort()

◆ Streamer()

◆ StreamerNVirtual()

◆ WaitFinishPrefetch()

Member Data Documentation

◆ fAsyncReading

◆ fBIsSorted

◆ fBIsTransferred

◆ fBLen

◆ fBNb

◆ fBNseek

◆ fBNtot

◆ fBPos

◆ fBSeek

◆ fBSeekIndex

◆ fBSeekLen

◆ fBSeekPos

◆ fBSeekSize

◆ fBSeekSort

◆ fBSeekSortLen

◆ fBuffer

◆ fBufferLen

◆ fBufferSize

◆ fBufferSizeMin

◆ fBytesRead

◆ fBytesReadExtra

◆ fEnablePrefetching

◆ fFile