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Reference Guide
TKey.h
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1// @(#)root/io
2// Author: Rene Brun 28/12/94
3
4/*************************************************************************
5 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers. *
6 * All rights reserved. *
7 * *
8 * For the licensing terms see $ROOTSYS/LICENSE. *
9 * For the list of contributors see $ROOTSYS/README/CREDITS. *
10 *************************************************************************/
11
12#ifndef ROOT_TKey
13#define ROOT_TKey
14
15#include "TNamed.h"
16#include "TDatime.h"
17#include "TBuffer.h"
18#include "TClass.h"
19
20class TBrowser;
21class TDirectory;
22class TFile;
23
24class TKey : public TNamed {
25
26private:
29 };
30 TKey(const TKey&); // TKey objects are not copiable.
31 TKey& operator=(const TKey&); // TKey objects are not copiable.
32
33protected:
34 Int_t fVersion; ///< Key version identifier
35 Int_t fNbytes; ///< Number of bytes for the object on file
36 Int_t fObjlen; ///< Length of uncompressed object in bytes
37 TDatime fDatime; ///< Date/Time of insertion in file
38 Short_t fKeylen; ///< Number of bytes for the key itself
39 Short_t fCycle; ///< Cycle number
40 Long64_t fSeekKey; ///< Location of object on file
41 Long64_t fSeekPdir; ///< Location of parent directory on file
42 TString fClassName; ///< Object Class name
43 Int_t fLeft; ///< Number of bytes left in current segment
44 char *fBuffer; ///< Object buffer
45 TBuffer *fBufferRef; ///< Pointer to the TBuffer object
46 UShort_t fPidOffset; ///<!Offset to be added to the pid index in this key/buffer. This is actually saved in the high bits of fSeekPdir
47 TDirectory *fMotherDir; ///<!pointer to mother directory
48
49 virtual Int_t Read(const char *name) { return TObject::Read(name); }
50 virtual void Create(Int_t nbytes, TFile* f = 0);
51 void Build(TDirectory* motherDir, const char* classname, Long64_t filepos);
52 virtual void Reset(); // Currently only for the use of TBasket.
53 virtual Int_t WriteFileKeepBuffer(TFile *f = 0);
54
55
56 public:
57 TKey();
58 TKey(TDirectory* motherDir);
59 TKey(TDirectory* motherDir, const TKey &orig, UShort_t pidOffset);
60 TKey(const char *name, const char *title, const TClass *cl, Int_t nbytes, TDirectory* motherDir);
61 TKey(const TString &name, const TString &title, const TClass *cl, Int_t nbytes, TDirectory* motherDir);
62 TKey(const TObject *obj, const char *name, Int_t bufsize, TDirectory* motherDir);
63 TKey(const void *obj, const TClass *cl, const char *name, Int_t bufsize, TDirectory* motherDir);
64 TKey(Long64_t pointer, Int_t nbytes, TDirectory* motherDir = 0);
65 virtual ~TKey();
66
67 virtual void Browse(TBrowser *b);
68 virtual void Delete(Option_t *option="");
69 virtual void DeleteBuffer();
70 virtual void FillBuffer(char *&buffer);
71 virtual const char *GetClassName() const {return fClassName.Data();}
72 virtual const char *GetIconName() const;
73 virtual const char *GetTitle() const;
74 virtual char *GetBuffer() const {return fBuffer+fKeylen;}
75 TBuffer *GetBufferRef() const {return fBufferRef;}
76 Short_t GetCycle() const;
77 const TDatime &GetDatime() const {return fDatime;}
78 TFile *GetFile() const;
79 Short_t GetKeep() const;
80 Int_t GetKeylen() const {return fKeylen;}
81 TDirectory* GetMotherDir() const { return fMotherDir; }
82 Int_t GetNbytes() const {return fNbytes;}
83 Int_t GetObjlen() const {return fObjlen;}
84 Int_t GetVersion() const {return fVersion;}
85 virtual Long64_t GetSeekKey() const {return fSeekKey;}
86 virtual Long64_t GetSeekPdir() const {return fSeekPdir;}
87 virtual void IncrementPidOffset(UShort_t offset);
88 Bool_t IsFolder() const;
89 virtual void Keep();
90 virtual void ls(Option_t *option="") const;
91 virtual void Print(Option_t *option="") const;
92 virtual Int_t Read(TObject *obj);
93 virtual TObject *ReadObj();
94 virtual TObject *ReadObjWithBuffer(char *bufferRead);
95 /// To read an object (non deriving from TObject) from the file.
96 /// This is more user friendly version of TKey::ReadObjectAny.
97 /// See TKey::ReadObjectAny for more details.
98 template <typename T> T *ReadObject() {
99 return reinterpret_cast<T*>(ReadObjectAny(TClass::GetClass(typeid(T))));
100 }
101 virtual void *ReadObjectAny(const TClass *expectedClass);
102 virtual void ReadBuffer(char *&buffer);
103 void ReadKeyBuffer(char *&buffer);
104 virtual Bool_t ReadFile();
105 virtual void SetBuffer() { fBuffer = new char[fNbytes];}
106 virtual void SetParent(const TObject *parent);
107 void SetMotherDir(TDirectory* dir) { fMotherDir = dir; }
108 virtual Int_t Sizeof() const;
109 virtual Int_t WriteFile(Int_t cycle=1, TFile* f = 0);
110
111 ClassDef(TKey,4); //Header description of a logical record on file.
112};
113
114#endif
#define b(i)
Definition: RSha256.hxx:100
#define f(i)
Definition: RSha256.hxx:104
unsigned short UShort_t
Definition: RtypesCore.h:36
int Int_t
Definition: RtypesCore.h:41
bool Bool_t
Definition: RtypesCore.h:59
short Short_t
Definition: RtypesCore.h:35
long long Long64_t
Definition: RtypesCore.h:69
const char Option_t
Definition: RtypesCore.h:62
#define ClassDef(name, id)
Definition: Rtypes.h:324
#define BIT(n)
Definition: Rtypes.h:82
Using a TBrowser one can browse all ROOT objects.
Definition: TBrowser.h:37
Buffer base class used for serializing objects.
Definition: TBuffer.h:40
The ROOT global object gROOT contains a list of all defined classes.
Definition: TClass.h:75
static TClass * GetClass(const char *name, Bool_t load=kTRUE, Bool_t silent=kFALSE)
Static method returning pointer to TClass of the specified class name.
Definition: TClass.cxx:2885
This class stores the date and time with a precision of one second in an unsigned 32 bit word (950130...
Definition: TDatime.h:37
Describe directory structure in memory.
Definition: TDirectory.h:34
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition: TFile.h:48
Book space in a file, create I/O buffers, to fill them, (un)compress them.
Definition: TKey.h:24
virtual void Print(Option_t *option="") const
Print key contents.
Definition: TKey.cxx:686
@ kIsDirectoryFile
Definition: TKey.h:28
virtual Long64_t GetSeekKey() const
Definition: TKey.h:85
virtual void FillBuffer(char *&buffer)
Encode key header into output buffer.
Definition: TKey.cxx:588
TKey()
TKey default constructor.
Definition: TKey.cxx:92
virtual void Delete(Option_t *option="")
Delete an object from the file.
Definition: TKey.cxx:534
TFile * GetFile() const
Returns file to which key belong.
Definition: TKey.cxx:572
virtual void Keep()
Set the "KEEP" status.
Definition: TKey.cxx:669
virtual Int_t WriteFileKeepBuffer(TFile *f=0)
Write the encoded object supported by this key.
Definition: TKey.cxx:1460
virtual const char * GetIconName() const
Title can keep 32x32 xpm thumbnail/icon of the parent object.
Definition: TKey.cxx:1493
Int_t GetVersion() const
Definition: TKey.h:84
virtual Int_t Read(const char *name)
Read contents of object with specified name from the current directory.
Definition: TKey.h:49
virtual void ls(Option_t *option="") const
List Key contents.
Definition: TKey.cxx:677
Int_t GetKeylen() const
Definition: TKey.h:80
TDatime fDatime
Date/Time of insertion in file.
Definition: TKey.h:37
Int_t GetObjlen() const
Definition: TKey.h:83
TBuffer * fBufferRef
Pointer to the TBuffer object.
Definition: TKey.h:45
T * ReadObject()
To read an object (non deriving from TObject) from the file.
Definition: TKey.h:98
UShort_t fPidOffset
!Offset to be added to the pid index in this key/buffer. This is actually saved in the high bits of f...
Definition: TKey.h:46
Int_t GetNbytes() const
Definition: TKey.h:82
virtual void IncrementPidOffset(UShort_t offset)
Increment fPidOffset by 'offset'.
Definition: TKey.cxx:634
Short_t GetKeep() const
Returns the "KEEP" status.
Definition: TKey.cxx:580
Int_t fVersion
Key version identifier.
Definition: TKey.h:34
virtual ~TKey()
TKey default destructor.
Definition: TKey.cxx:520
Int_t fLeft
Number of bytes left in current segment.
Definition: TKey.h:43
virtual const char * GetClassName() const
Definition: TKey.h:71
virtual void Create(Int_t nbytes, TFile *f=0)
Create a TKey object of specified size.
Definition: TKey.cxx:458
virtual const char * GetTitle() const
Returns title (title can contain 32x32 xpm thumbnail/icon).
Definition: TKey.cxx:1501
Short_t fKeylen
Number of bytes for the key itself.
Definition: TKey.h:38
TKey(const TKey &)
virtual Bool_t ReadFile()
Read the key structure from the file.
Definition: TKey.cxx:1237
virtual Int_t WriteFile(Int_t cycle=1, TFile *f=0)
Write the encoded object supported by this key.
Definition: TKey.cxx:1419
virtual void SetBuffer()
Definition: TKey.h:105
const TDatime & GetDatime() const
Definition: TKey.h:77
Long64_t fSeekKey
Location of object on file.
Definition: TKey.h:40
void Build(TDirectory *motherDir, const char *classname, Long64_t filepos)
Method used in all TKey constructor to initialize basic data fields.
Definition: TKey.cxx:391
char * fBuffer
Object buffer.
Definition: TKey.h:44
Long64_t fSeekPdir
Location of parent directory on file.
Definition: TKey.h:41
TKey & operator=(const TKey &)
virtual void SetParent(const TObject *parent)
Set parent in key buffer.
Definition: TKey.cxx:1266
Bool_t IsFolder() const
Check if object referenced by the key is a folder.
Definition: TKey.cxx:648
virtual void * ReadObjectAny(const TClass *expectedClass)
To read an object (non deriving from TObject) from the file.
Definition: TKey.cxx:987
void ReadKeyBuffer(char *&buffer)
Decode input buffer.
Definition: TKey.cxx:1194
Int_t fNbytes
Number of bytes for the object on file.
Definition: TKey.h:35
Int_t fObjlen
Length of uncompressed object in bytes.
Definition: TKey.h:36
virtual void Reset()
Reset the key as it had not been 'filled' yet.
Definition: TKey.cxx:1274
virtual Long64_t GetSeekPdir() const
Definition: TKey.h:86
void SetMotherDir(TDirectory *dir)
Definition: TKey.h:107
Short_t fCycle
Cycle number.
Definition: TKey.h:39
virtual TObject * ReadObjWithBuffer(char *bufferRead)
To read a TObject* from bufferRead.
Definition: TKey.cxx:856
TDirectory * GetMotherDir() const
Definition: TKey.h:81
Short_t GetCycle() const
Return cycle number associated to this key.
Definition: TKey.cxx:564
virtual TObject * ReadObj()
To read a TObject* from the file.
Definition: TKey.cxx:722
virtual void DeleteBuffer()
Delete key buffer(s).
Definition: TKey.cxx:546
virtual char * GetBuffer() const
Definition: TKey.h:74
virtual Int_t Sizeof() const
Return the size in bytes of the key header structure.
Definition: TKey.cxx:1308
virtual void ReadBuffer(char *&buffer)
Decode input buffer.
Definition: TKey.cxx:1182
TDirectory * fMotherDir
!pointer to mother directory
Definition: TKey.h:47
virtual void Browse(TBrowser *b)
Read object from disk and call its Browse() method.
Definition: TKey.cxx:426
TString fClassName
Object Class name.
Definition: TKey.h:42
TBuffer * GetBufferRef() const
Definition: TKey.h:75
The TNamed class is the base class for all named ROOT classes.
Definition: TNamed.h:29
Mother of all ROOT objects.
Definition: TObject.h:37
EStatusBits
Definition: TObject.h:57
virtual Int_t Read(const char *name)
Read contents of object with specified name from the current directory.
Definition: TObject.cxx:562
Basic string class.
Definition: TString.h:131
const char * Data() const
Definition: TString.h:364
double T(double x)
Definition: ChebyshevPol.h:34