| 1 |
loizides |
1.3 |
//--------------------------------------------------------------------------------------------------
|
| 2 |
loizides |
1.4 |
// $Id: BitMask.h,v 1.3 2008/09/17 04:09:26 loizides Exp $
|
| 3 |
loizides |
1.3 |
//
|
| 4 |
|
|
// BitMask
|
| 5 |
|
|
//
|
| 6 |
|
|
// Helper class implementing a Nx8 bit bitmask.
|
| 7 |
|
|
//
|
| 8 |
|
|
// Authors: J.Bendavid, C.Loizides
|
| 9 |
|
|
//--------------------------------------------------------------------------------------------------
|
| 10 |
|
|
|
| 11 |
|
|
#ifndef MITANA_DATATREE_BITMASK_H
|
| 12 |
|
|
#define MITANA_DATATREE_BITMASK_H
|
| 13 |
|
|
|
| 14 |
|
|
#include <assert.h>
|
| 15 |
|
|
#include <Rtypes.h>
|
| 16 |
|
|
|
| 17 |
|
|
namespace mithep
|
| 18 |
|
|
{
|
| 19 |
|
|
template<UInt_t N>
|
| 20 |
|
|
class BitMask
|
| 21 |
|
|
{
|
| 22 |
|
|
public:
|
| 23 |
|
|
BitMask() { Clear(); }
|
| 24 |
|
|
BitMask(const Char_t *bits) { SetBits(bits); }
|
| 25 |
|
|
virtual ~BitMask() {}
|
| 26 |
|
|
|
| 27 |
|
|
const Char_t *Bits() const { return fBitMask; }
|
| 28 |
|
|
void Clear() { memset(fBitMask,0,N); }
|
| 29 |
|
|
void ClearBit(UInt_t n) { SetBit(n,0); }
|
| 30 |
|
|
UInt_t NBitsSet(UInt_t first=0, UInt_t last=N*8) const;
|
| 31 |
|
|
void SetBit(UInt_t n, Bool_t b=1);
|
| 32 |
|
|
void SetBits(const Char_t *bits) { strncpy(fBitMask,bits,N); }
|
| 33 |
|
|
void SetBits(Long64_t bits);
|
| 34 |
|
|
UInt_t Size() const { return N*8; }
|
| 35 |
|
|
Bool_t TestBit(UInt_t n) const;
|
| 36 |
|
|
|
| 37 |
|
|
protected:
|
| 38 |
|
|
Char_t fBitMask[N]; //the actual bitmask
|
| 39 |
|
|
|
| 40 |
|
|
ClassDefT(BitMask, 1)
|
| 41 |
|
|
};
|
| 42 |
|
|
}
|
| 43 |
|
|
|
| 44 |
|
|
//--------------------------------------------------------------------------------------------------
|
| 45 |
|
|
template<UInt_t N>
|
| 46 |
|
|
inline void mithep::BitMask<N>::SetBit(UInt_t n, Bool_t b)
|
| 47 |
|
|
{
|
| 48 |
|
|
// Set nth bit to given value.
|
| 49 |
|
|
|
| 50 |
|
|
if(n>=N*8) return;
|
| 51 |
|
|
|
| 52 |
|
|
UInt_t loc = n/8;
|
| 53 |
|
|
UChar_t bit = n%8;
|
| 54 |
|
|
if (b)
|
| 55 |
|
|
fBitMask[loc] |= (1<<bit);
|
| 56 |
|
|
else
|
| 57 |
|
|
fBitMask[loc] &= (0xFF ^ (1<<bit));
|
| 58 |
|
|
}
|
| 59 |
|
|
|
| 60 |
|
|
//--------------------------------------------------------------------------------------------------
|
| 61 |
|
|
template<UInt_t N>
|
| 62 |
|
|
UInt_t mithep::BitMask<N>::NBitsSet(UInt_t first, UInt_t last) const
|
| 63 |
|
|
{
|
| 64 |
|
|
// Count number of bits which are set.
|
| 65 |
|
|
|
| 66 |
|
|
UInt_t numBits = 0;
|
| 67 |
|
|
for (UInt_t i=first; i<=last; i++)
|
| 68 |
|
|
numBits += TestBit(i);
|
| 69 |
|
|
|
| 70 |
|
|
return numBits;
|
| 71 |
|
|
}
|
| 72 |
|
|
|
| 73 |
|
|
//--------------------------------------------------------------------------------------------------
|
| 74 |
|
|
template<UInt_t N>
|
| 75 |
|
|
inline void mithep::BitMask<N>::SetBits(Long64_t bits)
|
| 76 |
|
|
{
|
| 77 |
|
|
// Set bits given by bits.
|
| 78 |
|
|
|
| 79 |
loizides |
1.4 |
assert(sizeof(Long64_t)>=N);
|
| 80 |
loizides |
1.3 |
SetBits(reinterpret_cast<const char*>(&bits));
|
| 81 |
|
|
}
|
| 82 |
|
|
|
| 83 |
|
|
//--------------------------------------------------------------------------------------------------
|
| 84 |
|
|
template<UInt_t N>
|
| 85 |
|
|
inline Bool_t mithep::BitMask<N>::TestBit(UInt_t n) const
|
| 86 |
|
|
{
|
| 87 |
|
|
// Return true if nth bit is set.
|
| 88 |
|
|
|
| 89 |
|
|
if(n>=N*8) return 0;
|
| 90 |
|
|
|
| 91 |
|
|
UInt_t loc = n/8;
|
| 92 |
|
|
UChar_t bit = n%8;
|
| 93 |
|
|
Char_t val = fBitMask[loc];
|
| 94 |
|
|
Bool_t result = (val & (1<<bit)) != 0;
|
| 95 |
|
|
return result;
|
| 96 |
|
|
}
|
| 97 |
|
|
#endif
|
