class TFileCacheRead: public TObject
TFileCacheRead : 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.
Function Members (Methods)
public:
| TFileCacheRead() | |
| TFileCacheRead(TFile* file, Int_t buffersize) | |
| virtual | ~TFileCacheRead() |
| void | TObject::AbstractMethod(const char* method) const |
| virtual void | AddBranch(TBranch*, Bool_t = kFALSE) |
| virtual void | AddBranch(const char*, Bool_t = kFALSE) |
| virtual void | TObject::AppendPad(Option_t* option = "") |
| virtual void | TObject::Browse(TBrowser* b) |
| static TClass* | Class() |
| virtual const char* | TObject::ClassName() const |
| virtual void | TObject::Clear(Option_t* = "") |
| virtual TObject* | TObject::Clone(const char* newname = "") const |
| virtual Int_t | TObject::Compare(const TObject* obj) const |
| virtual void | TObject::Copy(TObject& object) const |
| virtual void | TObject::Delete(Option_t* option = "")MENU |
| virtual Int_t | TObject::DistancetoPrimitive(Int_t px, Int_t py) |
| virtual void | TObject::Draw(Option_t* option = "") |
| virtual void | TObject::DrawClass() constMENU |
| virtual TObject* | TObject::DrawClone(Option_t* option = "") constMENU |
| virtual void | TObject::Dump() constMENU |
| virtual void | TObject::Error(const char* method, const char* msgfmt) const |
| virtual void | TObject::Execute(const char* method, const char* params, Int_t* error = 0) |
| virtual void | TObject::Execute(TMethod* method, TObjArray* params, Int_t* error = 0) |
| virtual void | TObject::ExecuteEvent(Int_t event, Int_t px, Int_t py) |
| virtual void | TObject::Fatal(const char* method, const char* msgfmt) const |
| virtual TObject* | TObject::FindObject(const char* name) const |
| virtual TObject* | TObject::FindObject(const TObject* obj) const |
| virtual Int_t | GetBufferSize() const |
| virtual Option_t* | TObject::GetDrawOption() const |
| static Long_t | TObject::GetDtorOnly() |
| virtual const char* | TObject::GetIconName() const |
| virtual const char* | TObject::GetName() const |
| virtual char* | TObject::GetObjectInfo(Int_t px, Int_t py) const |
| static Bool_t | TObject::GetObjectStat() |
| virtual Option_t* | TObject::GetOption() const |
| virtual const char* | TObject::GetTitle() const |
| virtual UInt_t | TObject::GetUniqueID() const |
| virtual Int_t | GetUnzipBuffer(char**, Long64_t, Int_t, Bool_t*) |
| virtual Bool_t | TObject::HandleTimer(TTimer* timer) |
| virtual ULong_t | TObject::Hash() const |
| virtual void | TObject::Info(const char* method, const char* msgfmt) const |
| virtual Bool_t | TObject::InheritsFrom(const char* classname) const |
| virtual Bool_t | TObject::InheritsFrom(const TClass* cl) const |
| virtual void | TObject::Inspect() constMENU |
| void | TObject::InvertBit(UInt_t f) |
| virtual TClass* | IsA() const |
| virtual Bool_t | IsAsyncReading() const |
| virtual Bool_t | TObject::IsEqual(const TObject* obj) const |
| virtual Bool_t | TObject::IsFolder() const |
| virtual Bool_t | IsLearning() const |
| Bool_t | TObject::IsOnHeap() const |
| virtual Bool_t | TObject::IsSortable() const |
| Bool_t | TObject::IsZombie() const |
| virtual void | TObject::ls(Option_t* option = "") const |
| void | TObject::MayNotUse(const char* method) const |
| virtual Bool_t | TObject::Notify() |
| static void | TObject::operator delete(void* ptr) |
| static void | TObject::operator delete(void* ptr, void* vp) |
| static void | TObject::operator delete[](void* ptr) |
| static void | TObject::operator delete[](void* ptr, void* vp) |
| void* | TObject::operator new(size_t sz) |
| void* | TObject::operator new(size_t sz, void* vp) |
| void* | TObject::operator new[](size_t sz) |
| void* | TObject::operator new[](size_t sz, void* vp) |
| virtual void | TObject::Paint(Option_t* option = "") |
| virtual void | TObject::Pop() |
| virtual void | Prefetch(Long64_t pos, Int_t len) |
| virtual void | Print(Option_t* option = "") const |
| virtual Int_t | TObject::Read(const char* name) |
| virtual Int_t | ReadBuffer(char* buf, Long64_t pos, Int_t len) |
| virtual Int_t | ReadBufferExt(char* buf, Long64_t pos, Int_t len, Int_t& loc) |
| virtual void | TObject::RecursiveRemove(TObject* obj) |
| void | TObject::ResetBit(UInt_t f) |
| virtual void | TObject::SaveAs(const char* filename = "", Option_t* option = "") constMENU |
| virtual void | TObject::SavePrimitive(basic_ostream<char,char_traits<char> >& out, Option_t* option = "") |
| void | TObject::SetBit(UInt_t f) |
| void | TObject::SetBit(UInt_t f, Bool_t set) |
| virtual void | TObject::SetDrawOption(Option_t* option = "")MENU |
| static void | TObject::SetDtorOnly(void* obj) |
| virtual void | SetFile(TFile* file) |
| static void | TObject::SetObjectStat(Bool_t stat) |
| virtual void | SetSkipZip(Bool_t = kTRUE) |
| virtual void | TObject::SetUniqueID(UInt_t uid) |
| virtual void | ShowMembers(TMemberInspector& insp, char* parent) |
| virtual void | Sort() |
| virtual void | Streamer(TBuffer& b) |
| void | StreamerNVirtual(TBuffer& b) |
| virtual void | TObject::SysError(const char* method, const char* msgfmt) const |
| Bool_t | TObject::TestBit(UInt_t f) const |
| Int_t | TObject::TestBits(UInt_t f) const |
| virtual void | TObject::UseCurrentStyle() |
| virtual void | TObject::Warning(const char* method, const char* msgfmt) const |
| virtual Int_t | TObject::Write(const char* name = 0, Int_t option = 0, Int_t bufsize = 0) |
| virtual Int_t | TObject::Write(const char* name = 0, Int_t option = 0, Int_t bufsize = 0) const |
protected:
| virtual void | TObject::DoError(int level, const char* location, const char* fmt, va_list va) const |
| void | TObject::MakeZombie() |
private:
| TFileCacheRead(const TFileCacheRead&) | |
| TFileCacheRead& | operator=(const TFileCacheRead&) |
Data Members
public:
| enum TObject::EStatusBits { | kCanDelete | |
| kMustCleanup | ||
| kObjInCanvas | ||
| kIsReferenced | ||
| kHasUUID | ||
| kCannotPick | ||
| kNoContextMenu | ||
| kInvalidObject | ||
| }; | ||
| enum TObject::[unnamed] { | kIsOnHeap | |
| kNotDeleted | ||
| kZombie | ||
| kBitMask | ||
| kSingleKey | ||
| kOverwrite | ||
| kWriteDelete | ||
| }; |
protected:
| Bool_t | fAsyncReading | |
| 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 |
| 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 |
| 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 |
| 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) |
Class Charts
Function documentation
void Prefetch(Long64_t pos, Int_t len)
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.
void Print(Option_t* option = "") const
Print cache statistics, like ******TreeCache statistics for file: cms2.root ****** Reading 73921562 bytes in 716 transactions Average transaction = 103.242405 Kbytes Number of blocks in current cache: 202, total size : 6001193 if option = "a" the list of blocks in the cache is printed
Int_t ReadBuffer(char* buf, Long64_t pos, Int_t len)
Int_t ReadBufferExt(char* buf, Long64_t pos, Int_t len, Int_t& loc)
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
void Sort()
Sort buffers to be prefetched in increasing order of positions. Merge consecutive blocks if necessary.
TFileCacheRead(const TFileCacheRead& )
TFileCacheRead& operator=(const TFileCacheRead& )