DataCont/interface/FastArrayBasic.h

//--------------------------------------------------------------------------------------------------
// $Id: FastArrayBasic.h,v 1.2 2009/02/27 09:16:30 bendavid Exp $
//
// FastArrayBasic
//
// Implementation of a "fast" array on the heap: Memory is dynamically allocated, 
// but there is an optimization in the read streamer similar to the TClonesArray
// where the heap memory of an existing object is reused.  
// This class is meant to be used as a datamember for objects which are contained 
// inside a TClonesArray. 
// For various reasons, the array can not be written in split mode. 
// Array is meant to store basic data types as opposed to FastArray 
// which can hold arbitrary (non-heap using) classes.
// Since it stores basic types it can not derive from the Collection<ArrayElement>
// interface, or else the At() member functions would have to return pointers to
// basic elements. Something we did not want to do.
//
// Authors: J.Bendavid
//--------------------------------------------------------------------------------------------------

#ifndef MITANA_DATACONT_FASTARRAYBASIC
#define MITANA_DATACONT_FASTARRAYBASIC

#include <TObject.h>
#include <TClass.h>
#include <TStorage.h>
#include "MitAna/DataCont/interface/Collection.h"

namespace mithep 
{
  template<class ArrayElement>
  class FastArrayBasic : public BaseCollection
  {
    public:
      FastArrayBasic();
      FastArrayBasic(const FastArrayBasic &a);
      ~FastArrayBasic() { Init(0); }

      void                      Add(const ArrayElement &ae);
      ArrayElement              At(UInt_t idx);
      const ArrayElement        At(UInt_t idx)                     const;
      void                      Clear(Option_t */*opt*/="")              { fSize=0; Init(0);    }
      UInt_t                    Entries()                          const { return fSize;        }
      UInt_t                    GetEntries()                       const { return Entries();    }
      UInt_t                    GetSize()                          const { return fCapacity;    }
      Bool_t                    IsOwner()                          const { return kTRUE;        }
      TObject                  *ObjAt(UInt_t idx)                        { return 0;            }
      const TObject            *ObjAt(UInt_t idx)                 const  { return 0;            }
      void                      Reset()                                  { fSize = 0;           }
      void                      Trim()                                   { Expand(fSize);       }
      ArrayElement              UncheckedAt(UInt_t idx);                 
      const ArrayElement        UncheckedAt(UInt_t idx)            const;
      ArrayElement              operator[](UInt_t idx);
      const ArrayElement        operator[](UInt_t idx)             const;

    protected:
      void                      Init(UShort_t s);
      void                      Expand(UShort_t s);
    
      UShort_t                  fSize;     //size of array
      UShort_t                  fCapacity; //!size of heap allocated
      ArrayElement             *fArray;    //!heap storage for objects

    ClassDef(FastArrayBasic,1) // Fast array for basic types
  };
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline mithep::FastArrayBasic<ArrayElement>::FastArrayBasic() : 
  fSize(0),
  fCapacity(0),
  fArray(0)
{
   // Default constructor.
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline mithep::FastArrayBasic<ArrayElement>::FastArrayBasic(const FastArrayBasic &a) : 
  fSize(0),
  fCapacity(0),
  fArray(0)
{
   // Copy constructor. Copy only elements which are used.

   Init(a.fSize);
   for (UInt_t i=0; i<a.fSize; ++i)
     Add(a.fArray[i]);
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
void mithep::FastArrayBasic<ArrayElement>::Add(const ArrayElement &ae)
{
  // Add a copy of an existing object.
  
  if (fSize >= fCapacity)
    Expand(TMath::Max(16,2*fCapacity));
   
  ++fSize; 
  fArray[fSize-1] = ae;
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline ArrayElement mithep::FastArrayBasic<ArrayElement>::At(UInt_t idx)
{
  // Return entry at given index. 

  if (idx<fSize)  
     return fArray[idx];

  ArrayElement tmp;
  TObject::Fatal("At","Index too large: (%u < %u violated) for %s containing %s",
                 idx, fSize, this->GetName(), typeid(tmp).name()); 
  return 0;
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline const ArrayElement mithep::FastArrayBasic<ArrayElement>::At(UInt_t idx) const
{
  // Return entry at given index.

  if (idx<fSize)  
     return fArray[idx];

  ArrayElement tmp;
  TObject::Fatal("At","Index too large: (%u < %u violated) for %s containing %s",
                 idx, fSize, this->GetName(), typeid(tmp).name()); 
  return 0;
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline void mithep::FastArrayBasic<ArrayElement>::Expand(UShort_t s)
{

  // Expand or shrink the array to given number of elements.
  
  if (s < fSize) {
    TObject::Fatal("Expand", "Cannot shrink FastArrayBasic to less than fSize");
    return;
  }
  
  if (!fArray || s==0) {
    Init(s);
    return;
  }
      
  if (fCapacity == s)
    return;
    
  fArray = static_cast<ArrayElement*>(TStorage::ReAlloc(fArray, s * sizeof(ArrayElement),
                                        fCapacity * sizeof(ArrayElement)));
  fCapacity = s;
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline void mithep::FastArrayBasic<ArrayElement>::Init(UShort_t s)
{

  // Initialize the array the heap.
  
  if (fArray && fCapacity != s) {
    TStorage::Dealloc(fArray);
    fArray = 0;
  }
  
  fCapacity = s;
  
  if (!fArray && fCapacity > 0)
    fArray = static_cast<ArrayElement*>(TStorage::Alloc(fCapacity*sizeof(ArrayElement)));
}

//-------------------------------------------------------------------------------------------------
template<class ArrayElement>
void mithep::FastArrayBasic<ArrayElement>::Streamer(TBuffer &b)
{
   // Stream all objects in the array to or from the I/O buffer.

  if (b.IsReading()) {
    b >> fSize;
    if (fSize) {
      if (fSize > fCapacity)
        Expand(TMath::Max(static_cast<Int_t>(fSize),2*fCapacity));
        
      b.ReadFastArray(fArray,fSize);
    }
  } else { /*writing*/
    b << fSize;
    if (fSize) {
      b.WriteFastArray(fArray,fSize);
    }
  }
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline ArrayElement mithep::FastArrayBasic<ArrayElement>::UncheckedAt(UInt_t idx)
{
  // Return entry at given index.

  return fArray[idx];
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline const ArrayElement mithep::FastArrayBasic<ArrayElement>::UncheckedAt(UInt_t idx) const
{
  // Return entry at given index.

  return fArray[idx];
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline const ArrayElement mithep::FastArrayBasic<ArrayElement>::operator[](UInt_t idx) const
{
  // Return entry at given index.

  return At(idx);
}

//--------------------------------------------------------------------------------------------------
template<class ArrayElement>
inline ArrayElement mithep::FastArrayBasic<ArrayElement>::operator[](UInt_t idx)
{
  // Return entry at given index.

  return At(idx);
}
#endif
Revision:	1.3
Committed:	Mon Mar 2 12:34:00 2009 UTC (16 years, 2 months ago) by loizides
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+20 -21 lines
Log Message:	Documentation, cleanup and object id removal.
#	User	Rev	Content
1	bendavid	1.1	//--------------------------------------------------------------------------------------------------
2	loizides	1.3	// $Id: FastArrayBasic.h,v 1.2 2009/02/27 09:16:30 bendavid Exp $
3	bendavid	1.1	//
4			// FastArrayBasic
5			//
6	loizides	1.3	// Implementation of a "fast" array on the heap: Memory is dynamically allocated,
7	bendavid	1.1	// but there is an optimization in the read streamer similar to the TClonesArray
8	loizides	1.3	// where the heap memory of an existing object is reused.
9			// This class is meant to be used as a datamember for objects which are contained
10			// inside a TClonesArray.
11			// For various reasons, the array can not be written in split mode.
12			// Array is meant to store basic data types as opposed to FastArray
13			// which can hold arbitrary (non-heap using) classes.
14			// Since it stores basic types it can not derive from the Collection<ArrayElement>
15			// interface, or else the At() member functions would have to return pointers to
16			// basic elements. Something we did not want to do.
17	bendavid	1.1	//
18			// Authors: J.Bendavid
19			//--------------------------------------------------------------------------------------------------
20
21			#ifndef MITANA_DATACONT_FASTARRAYBASIC
22			#define MITANA_DATACONT_FASTARRAYBASIC
23
24			#include <TObject.h>
25			#include <TClass.h>
26			#include <TStorage.h>
27			#include "MitAna/DataCont/interface/Collection.h"
28
29			namespace mithep
30			{
31			template<class ArrayElement>
32			class FastArrayBasic : public BaseCollection
33			{
34			public:
35			FastArrayBasic();
36			FastArrayBasic(const FastArrayBasic &a);
37			~FastArrayBasic() { Init(0); }
38
39			void Add(const ArrayElement &ae);
40			ArrayElement At(UInt_t idx);
41			const ArrayElement At(UInt_t idx) const;
42	loizides	1.3	void Clear(Option_t /opt*/="") { fSize=0; Init(0); }
43			UInt_t Entries() const { return fSize; }
44			UInt_t GetEntries() const { return Entries(); }
45	bendavid	1.1	UInt_t GetSize() const { return fCapacity; }
46			Bool_t IsOwner() const { return kTRUE; }
47			TObject *ObjAt(UInt_t idx) { return 0; }
48			const TObject *ObjAt(UInt_t idx) const { return 0; }
49			void Reset() { fSize = 0; }
50			void Trim() { Expand(fSize); }
51			ArrayElement UncheckedAt(UInt_t idx);
52			const ArrayElement UncheckedAt(UInt_t idx) const;
53			ArrayElement operator[](UInt_t idx);
54			const ArrayElement operator[](UInt_t idx) const;
55
56			protected:
57			void Init(UShort_t s);
58			void Expand(UShort_t s);
59
60			UShort_t fSize; //size of array
61			UShort_t fCapacity; //!size of heap allocated
62			ArrayElement *fArray; //!heap storage for objects
63
64	loizides	1.3	ClassDef(FastArrayBasic,1) // Fast array for basic types
65	bendavid	1.1	};
66			}
67
68			//--------------------------------------------------------------------------------------------------
69			template<class ArrayElement>
70			inline mithep::FastArrayBasic<ArrayElement>::FastArrayBasic() :
71			fSize(0),
72			fCapacity(0),
73			fArray(0)
74			{
75			// Default constructor.
76			}
77
78			//--------------------------------------------------------------------------------------------------
79			template<class ArrayElement>
80			inline mithep::FastArrayBasic<ArrayElement>::FastArrayBasic(const FastArrayBasic &a) :
81	bendavid	1.2	fSize(0),
82	bendavid	1.1	fCapacity(0),
83			fArray(0)
84			{
85			// Copy constructor. Copy only elements which are used.
86	loizides	1.3
87	bendavid	1.2	Init(a.fSize);
88	bendavid	1.1	for (UInt_t i=0; i<a.fSize; ++i)
89			Add(a.fArray[i]);
90			}
91
92			//--------------------------------------------------------------------------------------------------
93			template<class ArrayElement>
94			void mithep::FastArrayBasic<ArrayElement>::Add(const ArrayElement &ae)
95			{
96			// Add a copy of an existing object.
97
98			if (fSize >= fCapacity)
99			Expand(TMath::Max(16,2*fCapacity));
100
101			++fSize;
102			fArray[fSize-1] = ae;
103			}
104
105			//--------------------------------------------------------------------------------------------------
106			template<class ArrayElement>
107			inline ArrayElement mithep::FastArrayBasic<ArrayElement>::At(UInt_t idx)
108			{
109			// Return entry at given index.
110
111			if (idx<fSize)
112			return fArray[idx];
113
114			ArrayElement tmp;
115			TObject::Fatal("At","Index too large: (%u < %u violated) for %s containing %s",
116			idx, fSize, this->GetName(), typeid(tmp).name());
117			return 0;
118			}
119
120			//--------------------------------------------------------------------------------------------------
121			template<class ArrayElement>
122			inline const ArrayElement mithep::FastArrayBasic<ArrayElement>::At(UInt_t idx) const
123			{
124			// Return entry at given index.
125
126			if (idx<fSize)
127			return fArray[idx];
128
129			ArrayElement tmp;
130			TObject::Fatal("At","Index too large: (%u < %u violated) for %s containing %s",
131			idx, fSize, this->GetName(), typeid(tmp).name());
132			return 0;
133			}
134
135			//--------------------------------------------------------------------------------------------------
136			template<class ArrayElement>
137			inline void mithep::FastArrayBasic<ArrayElement>::Expand(UShort_t s)
138			{
139
140	loizides	1.3	// Expand or shrink the array to given number of elements.
141	bendavid	1.1
142			if (s < fSize) {
143			TObject::Fatal("Expand", "Cannot shrink FastArrayBasic to less than fSize");
144			return;
145			}
146
147			if (!fArray \|\| s==0) {
148			Init(s);
149			return;
150			}
151
152			if (fCapacity == s)
153			return;
154
155			fArray = static_cast<ArrayElement>(TStorage::ReAlloc(fArray, s sizeof(ArrayElement),
156			fCapacity * sizeof(ArrayElement)));
157			fCapacity = s;
158			}
159
160			//--------------------------------------------------------------------------------------------------
161			template<class ArrayElement>
162			inline void mithep::FastArrayBasic<ArrayElement>::Init(UShort_t s)
163			{
164
165	loizides	1.3	// Initialize the array the heap.
166	bendavid	1.1
167			if (fArray && fCapacity != s) {
168			TStorage::Dealloc(fArray);
169			fArray = 0;
170			}
171
172			fCapacity = s;
173
174	loizides	1.3	if (!fArray && fCapacity > 0)
175			fArray = static_cast<ArrayElement>(TStorage::Alloc(fCapacitysizeof(ArrayElement)));
176	bendavid	1.1	}
177
178			//-------------------------------------------------------------------------------------------------
179			template<class ArrayElement>
180			void mithep::FastArrayBasic<ArrayElement>::Streamer(TBuffer &b)
181			{
182			// Stream all objects in the array to or from the I/O buffer.
183
184			if (b.IsReading()) {
185			b >> fSize;
186			if (fSize) {
187			if (fSize > fCapacity)
188			Expand(TMath::Max(static_cast<Int_t>(fSize),2*fCapacity));
189
190			b.ReadFastArray(fArray,fSize);
191			}
192			} else { /writing/
193			b << fSize;
194			if (fSize) {
195			b.WriteFastArray(fArray,fSize);
196			}
197			}
198			}
199
200			//--------------------------------------------------------------------------------------------------
201			template<class ArrayElement>
202			inline ArrayElement mithep::FastArrayBasic<ArrayElement>::UncheckedAt(UInt_t idx)
203			{
204			// Return entry at given index.
205
206			return fArray[idx];
207			}
208
209			//--------------------------------------------------------------------------------------------------
210			template<class ArrayElement>
211			inline const ArrayElement mithep::FastArrayBasic<ArrayElement>::UncheckedAt(UInt_t idx) const
212			{
213			// Return entry at given index.
214
215			return fArray[idx];
216			}
217
218			//--------------------------------------------------------------------------------------------------
219			template<class ArrayElement>
220			inline const ArrayElement mithep::FastArrayBasic<ArrayElement>::operator[](UInt_t idx) const
221			{
222			// Return entry at given index.
223
224			return At(idx);
225			}
226
227			//--------------------------------------------------------------------------------------------------
228			template<class ArrayElement>
229			inline ArrayElement mithep::FastArrayBasic<ArrayElement>::operator[](UInt_t idx)
230			{
231			// Return entry at given index.
232
233			return At(idx);
234			}
235			#endif