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. | |
TFileCacheWrite (TFile *file, Int_t buffersize) | |
Creates a TFileCacheWrite data structure. | |
virtual | ~TFileCacheWrite () |
Destructor. | |
virtual Bool_t | Flush () |
Flush the current write buffer to the file. | |
virtual Int_t | GetBytesInCache () const |
virtual void | Print (Option_t *option="") const |
Print class internal structure. | |
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. | |
virtual void | SetFile (TFile *file) |
Set the file using this cache. | |
virtual Int_t | WriteBuffer (const char *buf, Long64_t pos, Int_t len) |
Write buffer at position pos in the write buffer. | |
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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 for instance with: gROOT->SetSelectedPad(gPad) . | |
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=0) |
Execute method on this object with the given parameter string, e.g. | |
virtual void | Execute (TMethod *method, TObjArray *params, Int_t *error=0) |
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. | |
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) |
Operator delete []. | |
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. | |
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=0, Int_t option=0, Int_t bufsize=0) |
Write this object to the current directory. | |
virtual Int_t | Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const |
Write this object to the current directory. | |
Protected Attributes | |
char * | fBuffer |
[fBufferSize] buffer of contiguous prefetched blocks | |
Int_t | fBufferSize |
Allocated size of fBuffer. | |
TFile * | fFile |
Pointer to file. | |
Int_t | fNtot |
Total size of cached blocks. | |
Bool_t | fRecursive |
flag to avoid recursive calls | |
Long64_t | fSeekStart |
Seek value of first block in cache. | |
Private Member Functions | |
TFileCacheWrite (const TFileCacheWrite &)=delete | |
TFileCacheWrite & | operator= (const TFileCacheWrite &)=delete |
Additional Inherited Members | |
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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) } |
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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. | |
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enum | { kOnlyPrepStep = BIT(3) } |
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virtual void | DoError (int level, const char *location, const char *fmt, va_list va) const |
Interface to ErrorHandler (protected). | |
void | MakeZombie () |
#include <TFileCacheWrite.h>
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privatedelete |
TFileCacheWrite::TFileCacheWrite | ( | ) |
Default Constructor.
Definition at line 37 of file TFileCacheWrite.cxx.
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.
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virtual |
Destructor.
Definition at line 70 of file TFileCacheWrite.cxx.
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virtual |
Flush the current write buffer to the file.
Returns kTRUE in case of error.
Definition at line 79 of file TFileCacheWrite.cxx.
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inlinevirtual |
Definition at line 38 of file TFileCacheWrite.h.
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privatedelete |
Print class internal structure.
Reimplemented from TObject.
Definition at line 94 of file TFileCacheWrite.cxx.
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.
Set the file using this cache.
Any write not yet flushed will be lost.
Definition at line 153 of file TFileCacheWrite.cxx.
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.
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protected |
[fBufferSize] buffer of contiguous prefetched blocks
Definition at line 26 of file TFileCacheWrite.h.
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protected |
Allocated size of fBuffer.
Definition at line 23 of file TFileCacheWrite.h.
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protected |
Pointer to file.
Definition at line 25 of file TFileCacheWrite.h.
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protected |
Total size of cached blocks.
Definition at line 24 of file TFileCacheWrite.h.
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protected |
flag to avoid recursive calls
Definition at line 27 of file TFileCacheWrite.h.
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protected |
Seek value of first block in cache.
Definition at line 22 of file TFileCacheWrite.h.