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Reference Guide
TTreeRow.cxx
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1// @(#)root/tree:$Id$
2// Author: Fons Rademakers 30/11/99
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/** \class TTreeRow
13\ingroup tree
14
15Class defining interface to a row of a TTree query result.
16Objects of this class are created by TTreeResult methods.
17
18Related classes are TTreeResult.
19*/
20
21#include "TTreeRow.h"
22#include "TBuffer.h"
23#include "TObjArray.h"
24
26
27////////////////////////////////////////////////////////////////////////////////
28/// Single row of a query result.
29
31{
32 fColumnCount = 0;
33 fFields = 0;
34 fOriginal = 0;
35 fRow = 0;
36
37}
38
39////////////////////////////////////////////////////////////////////////////////
40/// Single row of a query result.
41
43{
44 fColumnCount = nfields;
45 fFields = 0;
46 fOriginal = 0;
47 fRow = 0;
48
49}
50
51////////////////////////////////////////////////////////////////////////////////
52/// Single row of a query result.
53
54TTreeRow::TTreeRow(Int_t nfields, const Int_t *fields, const char *row)
55{
56 fColumnCount = nfields;
57 fFields = 0;
58 fOriginal = 0;
59 fRow = 0;
60 SetRow(fields,row);
61}
62
63////////////////////////////////////////////////////////////////////////////////
64/// This is a shallow copy of a real row, i.e. it only contains
65/// a pointer to the original.
66
68{
69 fFields = 0;
70 fOriginal = 0;
71 fColumnCount = 0;
72 fRow = 0;
73
74 if (!original) {
75 Error("TTreeRow", "original may not be 0");
76 return;
77 }
78 if (original->IsA() != TTreeRow::Class()) {
79 Error("TTreeRow", "original must be a TTreeRow");
80 return;
81 }
82
83 fOriginal = (TTreeRow*) original;
85}
86
87////////////////////////////////////////////////////////////////////////////////
88/// Destroy row object.
89
91{
92 if (fFields)
93 Close();
94}
95
96////////////////////////////////////////////////////////////////////////////////
97/// Close row.
98
100{
101 if (fRow) delete [] fRow;
102 if (fFields) delete [] fFields;
103 fColumnCount = 0;
104 fOriginal = 0;
105}
106
107////////////////////////////////////////////////////////////////////////////////
108/// Check if row is open and field index within range.
109
111{
112 if (!fFields && !fOriginal) {
113 Error("IsValid", "row closed");
114 return kFALSE;
115 }
116 if (field < 0 || field >= fColumnCount) {
117 Error("IsValid", "field index out of bounds");
118 return kFALSE;
119 }
120 return kTRUE;
121}
122
123////////////////////////////////////////////////////////////////////////////////
124/// Get length in bytes of specified field.
125
127{
128 if (!IsValid(field))
129 return 0;
130
131 if (fOriginal)
132 return fOriginal->GetFieldLength(field);
133
134 if (field > 0) return fFields[field] - fFields[field-1] -1;
135 else return fFields[0] -1;
136}
137
138////////////////////////////////////////////////////////////////////////////////
139/// Get specified field from row (0 <= field < GetFieldCount()).
140
141const char *TTreeRow::GetField(Int_t field)
142{
143 if (!IsValid(field))
144 return 0;
145
146 if (fOriginal)
147 return fOriginal->GetField(field);
148
149 if (field > 0) return fRow +fFields[field-1];
150 else return fRow;
151}
152
153////////////////////////////////////////////////////////////////////////////////
154/// The field and row information.
155
156void TTreeRow::SetRow(const Int_t *fields, const char *row)
157{
158 if (!fColumnCount) return;
159 if (fFields) delete [] fFields;
160 Int_t nch = fields[fColumnCount-1];
162 fOriginal = 0;
163 fRow = new char[nch];
164 for (Int_t i=0;i<fColumnCount;i++) fFields[i] = fields[i];
165 memcpy(fRow,row,nch);
166}
167
168////////////////////////////////////////////////////////////////////////////////
169/// Stream an object of class TTreeRow.
170
171void TTreeRow::Streamer(TBuffer &R__b)
172{
173 UInt_t R__s, R__c;
174 if (R__b.IsReading()) {
175 R__b.ReadVersion(&R__s, &R__c);
176 TSQLRow::Streamer(R__b);
177 R__b >> fColumnCount;
180 Int_t nch;
181 R__b >> nch;
182 fRow = new char[nch];
183 R__b.ReadFastArray(fRow,nch);
184 R__b.CheckByteCount(R__s, R__c, TTreeRow::IsA());
185 } else {
186 R__c = R__b.WriteVersion(TTreeRow::Class(),kTRUE);
187 TSQLRow::Streamer(R__b);
188 R__b << fColumnCount;
190 Int_t nch = fFields ? fFields[fColumnCount-1] : 0;
191 R__b << nch;
192 R__b.WriteFastArray(fRow,nch);
193 R__b.SetByteCount(R__c,kTRUE);
194 }
195}
void Class()
Definition: Class.C:29
int Int_t
Definition: RtypesCore.h:41
unsigned int UInt_t
Definition: RtypesCore.h:42
const Bool_t kFALSE
Definition: RtypesCore.h:88
unsigned long ULong_t
Definition: RtypesCore.h:51
bool Bool_t
Definition: RtypesCore.h:59
const Bool_t kTRUE
Definition: RtypesCore.h:87
const char Option_t
Definition: RtypesCore.h:62
#define ClassImp(name)
Definition: Rtypes.h:363
Buffer base class used for serializing objects.
Definition: TBuffer.h:40
virtual void SetByteCount(UInt_t cntpos, Bool_t packInVersion=kFALSE)=0
virtual Version_t ReadVersion(UInt_t *start=0, UInt_t *bcnt=0, const TClass *cl=0)=0
virtual Int_t CheckByteCount(UInt_t startpos, UInt_t bcnt, const TClass *clss)=0
virtual void ReadFastArray(Bool_t *b, Int_t n)=0
Bool_t IsReading() const
Definition: TBuffer.h:83
virtual UInt_t WriteVersion(const TClass *cl, Bool_t useBcnt=kFALSE)=0
virtual void WriteFastArray(const Bool_t *b, Int_t n)=0
virtual void Error(const char *method, const char *msgfmt,...) const
Issue error message.
Definition: TObject.cxx:880
Class defining interface to a row of a TTree query result.
Definition: TTreeRow.h:29
Int_t fColumnCount
number of columns in row
Definition: TTreeRow.h:35
const char * GetField(Int_t field)
Get specified field from row (0 <= field < GetFieldCount()).
Definition: TTreeRow.cxx:141
Int_t * fFields
[fColumnCount] index in fRow of the end of each field
Definition: TTreeRow.h:36
void SetRow(const Int_t *fields, const char *row)
The field and row information.
Definition: TTreeRow.cxx:156
TTreeRow * fOriginal
! pointer to original row
Definition: TTreeRow.h:38
virtual ~TTreeRow()
Destroy row object.
Definition: TTreeRow.cxx:90
char * fRow
string with all the fColumnCount fields
Definition: TTreeRow.h:37
TTreeRow()
Single row of a query result.
Definition: TTreeRow.cxx:30
void Close(Option_t *option="")
Close row.
Definition: TTreeRow.cxx:99
Bool_t IsValid(Int_t field)
Check if row is open and field index within range.
Definition: TTreeRow.cxx:110
ULong_t GetFieldLength(Int_t field)
Get length in bytes of specified field.
Definition: TTreeRow.cxx:126