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Reference Guide
List of all members | Public Member Functions | Protected Attributes | Private Member Functions | List of all members
TFileCacheWrite Class Reference

A cache when writing 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 write cache system is used by the classes TNetFile, TXNetFile and TWebFile (via TFile::WriteBuffers()).

The write cache is automatically created when writing a remote file (created in TFile::Open()).

Definition at line 19 of file TFileCacheWrite.h.

Public Member Functions

 TFileCacheWrite ()
 Default Constructor. More...
 
 TFileCacheWrite (TFile *file, Int_t buffersize)
 Creates a TFileCacheWrite data structure. More...
 
virtual ~TFileCacheWrite ()
 Destructor. More...
 
virtual Bool_t Flush ()
 Flush the current write buffer to the file. More...
 
virtual Int_t GetBytesInCache () const
 
virtual void Print (Option_t *option="") const
 Print class internal structure. More...
 
virtual Int_t ReadBuffer (char *buf, Long64_t pos, Int_t len)
 Called by the read cache to check if the requested data is not in the write cache buffer. More...
 
virtual void SetFile (TFile *file)
 Set the file using this cache. More...
 
virtual Int_t WriteBuffer (const char *buf, Long64_t pos, Int_t len)
 Write buffer at position pos in the write buffer. More...
 
- Public Member Functions inherited from TObject
 TObject ()
 TObject constructor. More...
 
 TObject (const TObject &object)
 TObject copy ctor. More...
 
virtual ~TObject ()
 TObject destructor. 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...
 
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...
 
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. More...
 
virtual const char * ClassName () const
 Returns name of class to which the object belongs. More...
 
virtual void Clear (Option_t *="")
 
virtual TObjectClone (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 TObjectDrawClone (Option_t *option="") const
 Draw a clone of this object in the current selected pad for instance with: gROOT->SetSelectedPad(gPad). More...
 
virtual void Dump () const
 Dump contents of object on stdout. More...
 
virtual void Error (const char *method, const char *msgfmt,...) const
 Issue error message. 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 void Fatal (const char *method, const char *msgfmt,...) const
 Issue fatal error message. More...
 
virtual TObjectFindObject (const char *name) const
 Must be redefined in derived classes. More...
 
virtual TObjectFindObject (const TObject *obj) const
 Must be redefined in derived classes. More...
 
virtual Option_tGetDrawOption () const
 Get option used by the graphics system to draw this object. More...
 
virtual const char * GetIconName () const
 Returns mime type name of object. More...
 
virtual const char * GetName () const
 Returns name of object. More...
 
virtual char * GetObjectInfo (Int_t px, Int_t py) const
 Returns string containing info about the object at position (px,py). More...
 
virtual Option_tGetOption () const
 
virtual const char * GetTitle () const
 Returns title of object. More...
 
virtual UInt_t GetUniqueID () const
 Return the unique object id. 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...
 
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. More...
 
virtual void Info (const char *method, const char *msgfmt,...) const
 Issue info message. 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...
 
void InvertBit (UInt_t f)
 
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 IsFolder () const
 Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). More...
 
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. 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...
 
virtual Bool_t Notify ()
 This method must be overridden to handle object notification. More...
 
void Obsolete (const char *method, const char *asOfVers, const char *removedFromVers) const
 Use this method to declare a method obsolete. More...
 
void operator delete (void *ptr)
 Operator delete. More...
 
void operator delete[] (void *ptr)
 Operator delete []. More...
 
voidoperator new (size_t sz)
 
voidoperator new (size_t sz, void *vp)
 
voidoperator new[] (size_t sz)
 
voidoperator new[] (size_t sz, void *vp)
 
TObjectoperator= (const TObject &rhs)
 TObject assignment operator. 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...
 
void ResetBit (UInt_t f)
 
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...
 
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)
 
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 SysError (const char *method, const char *msgfmt,...) const
 Issue system error message. More...
 
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. More...
 
virtual void Warning (const char *method, const char *msgfmt,...) const
 Issue warning message. 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...
 

Protected Attributes

char * fBuffer
 [fBufferSize] buffer of contiguous prefetched blocks More...
 
Int_t fBufferSize
 Allocated size of fBuffer. More...
 
TFilefFile
 Pointer to file. More...
 
Int_t fNtot
 Total size of cached blocks. More...
 
Bool_t fRecursive
 flag to avoid recursive calls More...
 
Long64_t fSeekStart
 Seek value of first block in cache. More...
 

Private Member Functions

 TFileCacheWrite (const TFileCacheWrite &)
 
TFileCacheWriteoperator= (const TFileCacheWrite &)
 

Additional Inherited Members

- 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)
}
 
- Static Public Member Functions inherited from TObject
static Long_t GetDtorOnly ()
 Return destructor only flag. More...
 
static Bool_t GetObjectStat ()
 Get status of object stat flag. More...
 
static void SetDtorOnly (void *obj)
 Set destructor only flag. More...
 
static void SetObjectStat (Bool_t stat)
 Turn on/off tracking of objects in the TObjectTable. More...
 
- 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). More...
 
void MakeZombie ()
 

#include <TFileCacheWrite.h>

Inheritance diagram for TFileCacheWrite:
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Constructor & Destructor Documentation

◆ TFileCacheWrite() [1/3]

TFileCacheWrite::TFileCacheWrite ( const TFileCacheWrite )
private

◆ TFileCacheWrite() [2/3]

TFileCacheWrite::TFileCacheWrite ( )

Default Constructor.

Definition at line 37 of file TFileCacheWrite.cxx.

◆ TFileCacheWrite() [3/3]

TFileCacheWrite::TFileCacheWrite ( TFile file,
Int_t  buffersize 
)

Creates a TFileCacheWrite data structure.

The write cache will be connected to file. The size of the cache will be buffersize, if buffersize < 10000 a default size of 512 Kbytes is used

Definition at line 53 of file TFileCacheWrite.cxx.

◆ ~TFileCacheWrite()

TFileCacheWrite::~TFileCacheWrite ( )
virtual

Destructor.

Definition at line 70 of file TFileCacheWrite.cxx.

Member Function Documentation

◆ Flush()

Bool_t TFileCacheWrite::Flush ( )
virtual

Flush the current write buffer to the file.

Returns kTRUE in case of error.

Definition at line 79 of file TFileCacheWrite.cxx.

◆ GetBytesInCache()

virtual Int_t TFileCacheWrite::GetBytesInCache ( ) const
inlinevirtual

Definition at line 38 of file TFileCacheWrite.h.

◆ operator=()

TFileCacheWrite& TFileCacheWrite::operator= ( const TFileCacheWrite )
private

◆ Print()

void TFileCacheWrite::Print ( Option_t option = "") const
virtual

Print class internal structure.

Reimplemented from TObject.

Definition at line 94 of file TFileCacheWrite.cxx.

◆ ReadBuffer()

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

Called by the read cache to check if the requested data is not in the write cache buffer.

Returns -1 if data not in write cache, 0 otherwise.

Definition at line 108 of file TFileCacheWrite.cxx.

◆ SetFile()

void TFileCacheWrite::SetFile ( TFile file)
virtual

Set the file using this cache.

Any write not yet flushed will be lost.

Definition at line 153 of file TFileCacheWrite.cxx.

◆ WriteBuffer()

Int_t TFileCacheWrite::WriteBuffer ( const char *  buf,
Long64_t  pos,
Int_t  len 
)
virtual

Write buffer at position pos in the write buffer.

The function returns 1 if the buffer has been successfully entered into the write buffer. The function returns 0 in case WriteBuffer() was recusively called via Flush(). The function returns -1 in case of error.

Definition at line 121 of file TFileCacheWrite.cxx.

Member Data Documentation

◆ fBuffer

char* TFileCacheWrite::fBuffer
protected

[fBufferSize] buffer of contiguous prefetched blocks

Definition at line 26 of file TFileCacheWrite.h.

◆ fBufferSize

Int_t TFileCacheWrite::fBufferSize
protected

Allocated size of fBuffer.

Definition at line 23 of file TFileCacheWrite.h.

◆ fFile

TFile* TFileCacheWrite::fFile
protected

Pointer to file.

Definition at line 25 of file TFileCacheWrite.h.

◆ fNtot

Int_t TFileCacheWrite::fNtot
protected

Total size of cached blocks.

Definition at line 24 of file TFileCacheWrite.h.

◆ fRecursive

Bool_t TFileCacheWrite::fRecursive
protected

flag to avoid recursive calls

Definition at line 27 of file TFileCacheWrite.h.

◆ fSeekStart

Long64_t TFileCacheWrite::fSeekStart
protected

Seek value of first block in cache.

Definition at line 22 of file TFileCacheWrite.h.

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