PhysicsTools::BitSet Class Reference

A compact container for storing single bits. More...

#include <BitSet.h>

Classes
class	Iterator
	Iterates over all set bits of a BitSet. More...
class	Manipulator
	Opaque structure for transparent write access to individual bits. More...

Public Types
typedef std::size_t	size_t

Public Member Functions
size_t	bits () const
	returns the number of set bits in the container More...
	BitSet ()
	BitSet (const BitSet &orig)
	BitSet (size_t bits)
	construct BitSet with a fixed size of bits bits More...
Iterator	iter () const
	create iterator over all set bits More...
BitSet &	operator= (const BitSet &orig)
Manipulator	operator[] (size_t bit)
	provide read/write access to bit with index bit via reference More...
const Manipulator	operator[] (size_t bit) const
	provide read access to bit with index bit via reference More...
size_t	size () const
	returns the number of all bits in the container More...
	~BitSet ()

Protected Types
typedef unsigned int	Word_t

Static Private Member Functions
static size_t	bitsToWords (std::size_t bits)

Private Attributes
size_t	bits_
Word_t *	store

Static Private Attributes
static const unsigned int	wordSize = sizeof(Word_t) * 8

Detailed Description

A compact container for storing single bits.

BitSet provides a container of boolean values, similar to a std::vector<bool> which only consumes one actual bit for each value. Also an iterator is provided that can iterate over all set bits.

Definition at line 29 of file BitSet.h.

Member Typedef Documentation

typedef std::size_t PhysicsTools::BitSet::size_t

Definition at line 31 of file BitSet.h.

typedef unsigned int PhysicsTools::BitSet::Word_t

protected

Definition at line 34 of file BitSet.h.

Constructor & Destructor Documentation

PhysicsTools::BitSet::BitSet ( )

inline

Definition at line 126 of file BitSet.h.

: store(0), bits_(0) {}

PhysicsTools::BitSet::BitSet ( const BitSet &  orig )

inline

Definition at line 128 of file BitSet.h.

References bits_, bitsToWords(), and store.

                               : bits_(orig.bits_)
    {
        std::size_t words = bitsToWords(bits_);
        if (words) {
            store = new Word_t[words];
            std::memcpy(store, orig.store, words * sizeof(Word_t));
        } else
            store = 0;
    }

PhysicsTools::BitSet::BitSet ( size_t  bits )

inline

construct BitSet with a fixed size of bits bits

Definition at line 139 of file BitSet.h.

References bitsToWords(), and store.

                        : bits_(bits)
    {
        std::size_t words = bitsToWords(bits);
        if (words) {
            store = new Word_t[words];
            std::memset(store, 0, sizeof(Word_t) * words);
        } else
            store = 0;
    }

PhysicsTools::BitSet::~BitSet ( )

inline

Definition at line 149 of file BitSet.h.

References store.

{ delete[] store; }

Member Function Documentation

BitSet::size_t PhysicsTools::BitSet::bits

(

)

const

returns the number of set bits in the container

Definition at line 6 of file BitSet.cc.

References begin, bits_, bitsToWords(), constexpr, end, AlCaHLTBitMon_ParallelJobs::p, and store.

Referenced by size().

{
    static constexpr unsigned char byteBits[256] = {
        0,  1,  1,  2,  1,  2,  2,  3,  1,  2,  2,  3,  2,  3,  3,    
        4,  1,  2,  2,  3,  2,  3,  3,  4,  2,  3,  3,  4,  3,  4,
        4,  5,  1,  2,  2,  3,  2,  3,  3,  4,  2,  3,  3,  4,  3,    
        4,  4,  5,  2,  3,  3,  4,  3,  4,  4,  5,  3,  4,  4,  5,    
        4,  5,  5,  6,  1,  2,  2,  3,  2,  3,  3,  4,  2,  3,  3,    
        4,  3,  4,  4,  5,  2,  3,  3,  4,  3,  4,  4,  5,  3,  4,
        4,  5,  4,  5,  5,  6,  2,  3,  3,  4,  3,  4,  4,  5,  3,
        4,  4,  5,  4,  5,  5,  6,  3,  4,  4,  5,  4,  5,  5,  6,
        4,  5,  5,  6,  5,  6,  6,  7,  1,  2,  2,  3,  2,  3,  3,    
        4,  2,  3,  3,  4,  3,  4,  4,  5,  2,  3,  3,  4,  3,  4,    
        4,  5,  3,  4,  4,  5,  4,  5,  5,  6,  2,  3,  3,  4,  3,    
        4,  4,  5,  3,  4,  4,  5,  4,  5,  5,  6,  3,  4,  4,  5,    
        4,  5,  5,  6,  4,  5,  5,  6,  5,  6,  6,  7,  2,  3,  3,
        4,  3,  4,  4,  5,  3,  4,  4,  5,  4,  5,  5,  6,  3,  4,    
        4,  5,  4,  5,  5,  6,  4,  5,  5,  6,  5,  6,  6,  7,  3,    
        4,  4,  5,  4,  5,  5,  6,  4,  5,  5,  6,  5,  6,  6,  7,
        4,  5,  5,  6,  5,  6,  6,  7,  5,  6,  6,  7,  6,  7,  7,    
        8
    };
    const unsigned char *begin = reinterpret_cast<const unsigned char*>(store);
    const unsigned char *end   = reinterpret_cast<const unsigned char*>(store + bitsToWords(bits_));

    size_t bits = 0;
    for(const unsigned char *p = begin; p < end; p++)
        bits += byteBits[*p];

    return bits;
}

static size_t PhysicsTools::BitSet::bitsToWords ( std::size_t  bits )

inlinestaticprivate

Definition at line 183 of file BitSet.h.

References wordSize.

Referenced by bits(), BitSet(), iter(), and operator=().

    { return (bits + wordSize - 1) / wordSize; }

Iterator PhysicsTools::BitSet::iter ( ) const

inline

create iterator over all set bits

Definition at line 179 of file BitSet.h.

References bits_, bitsToWords(), and store.

Referenced by PhysicsTools::VarProcessor::configure(), PhysicsTools::VarProcessor::deriv(), and PhysicsTools::VarProcessor::eval().

    { return Iterator(store, store + bitsToWords(bits_)); }

BitSet& PhysicsTools::BitSet::operator= ( const BitSet &  orig )

inline

Definition at line 151 of file BitSet.h.

References bits_, bitsToWords(), and store.

    {
        delete[] store;
        bits_ = orig.bits_;
        std::size_t words = bitsToWords(bits_);
        if (words) {
            store = new Word_t[words];
            std::memcpy(store, orig.store, words * sizeof(Word_t));
        } else
            store = 0;
        return *this;
    }

Manipulator PhysicsTools::BitSet::operator[] ( size_t  bit )

inline

provide read/write access to bit with index bit via reference

Definition at line 165 of file BitSet.h.

References PhysicsTools::BitSet::Manipulator::Manipulator(), store, and wordSize.

    { return Manipulator(&store[bit / wordSize], bit % wordSize); }

const Manipulator PhysicsTools::BitSet::operator[] ( size_t  bit ) const

inline

provide read access to bit with index bit via reference

Definition at line 169 of file BitSet.h.

References PhysicsTools::BitSet::Manipulator::Manipulator(), store, and wordSize.

    { return Manipulator(&store[bit / wordSize], bit % wordSize); }

size_t PhysicsTools::BitSet::size ( void  ) const

inline

returns the number of all bits in the container

Definition at line 173 of file BitSet.h.

References bits(), and bits_.

Referenced by ntuple._Collection::__iter__(), ntuple._Collection::__len__(), PhysicsTools::VarProcessor::configure(), and PhysicsTools::Calibration::convert().

{ return bits_; }

Member Data Documentation

size_t PhysicsTools::BitSet::bits_

private

Definition at line 189 of file BitSet.h.

Referenced by bits(), BitSet(), iter(), operator=(), and size().

Word_t* PhysicsTools::BitSet::store

private

Definition at line 188 of file BitSet.h.

Referenced by bits(), BitSet(), iter(), PhysicsTools::BitSet::Iterator::Iterator(), PhysicsTools::BitSet::Iterator::operator bool(), PhysicsTools::BitSet::Iterator::operator()(), PhysicsTools::BitSet::Iterator::operator++(), operator=(), operator[](), and ~BitSet().

const unsigned int PhysicsTools::BitSet::wordSize = sizeof(Word_t) * 8

staticprivate

Definition at line 186 of file BitSet.h.

Referenced by bitsToWords(), PhysicsTools::BitSet::Iterator::operator()(), PhysicsTools::BitSet::Iterator::operator++(), and operator[]().