Program Listing for File EliasFano.h

↰ Return to documentation for file (ADS/succinct/EliasFano.h)

/*--------------------------------------------------------------------------*/
/*---------------------------- File EliasFano.h ----------------------------*/
/*--------------------------------------------------------------------------*/
/*--------------------------------------------------------------------------*/
/*----------------------------- DEFINITIONS --------------------------------*/
/*--------------------------------------------------------------------------*/

#ifndef __ADS_EliasFano
 #define __ADS_EliasFano
                      /* self-identification: #endif constant */

/*--------------------------------------------------------------------------*/
/*------------------------------ INCLUDES ----------------------------------*/
/*--------------------------------------------------------------------------*/

#include "ADS/Contract.h"
#include "ADS/combinatorial/Bitwise.h"
#include "ADS/succinct/BitVector.h"
#include "ADS/succinct/RankSelect.h"

#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <vector>

/*--------------------------------------------------------------------------*/
/*--------------------------- NAMESPACE ------------------------------------*/
/*--------------------------------------------------------------------------*/

namespace ADS {

/*--------------------------------------------------------------------------*/
/*-------------------------- CLASS BasicEliasFano --------------------------*/
/*--------------------------------------------------------------------------*/

template< bool Lazy >
class BasicEliasFano {

/*--------------------------------------------------------------------------*/
 public:

 BasicEliasFano( void ) = default;

 explicit BasicEliasFano( const std::vector< std::uint64_t > & x );

 BasicEliasFano( const std::vector< std::uint64_t > & x , std::uint64_t u );

 [[nodiscard]] std::size_t size( void ) const;

 [[nodiscard]] bool empty( void ) const;

 [[nodiscard]] std::uint64_t universe( void ) const;

 [[nodiscard]] std::uint64_t access( std::size_t i ) const;

 [[nodiscard]] std::uint64_t operator[]( std::size_t i ) const;

 [[nodiscard]] std::size_t nextGEQ( std::uint64_t x ) const;

 [[nodiscard]] bool contains( std::uint64_t x ) const;

 [[nodiscard]] int lowWidth( void ) const;

 [[nodiscard]] const BitVector & low( void ) const;

 [[nodiscard]] const BasicRankSelect< Lazy > & high( void ) const;

 [[nodiscard]] std::size_t codeBits( void ) const;

 [[nodiscard]] std::size_t sizeInBits( void ) const;

 [[nodiscard]] std::vector< std::uint64_t > decode( void ) const;

/*------------------------- THE STANDARD INTERFACE -------------------------*/

 using value_type = std::uint64_t;
 using size_type = std::size_t;
 using difference_type = std::ptrdiff_t;
 using reference = std::uint64_t;
 using const_reference = std::uint64_t;
 using const_iterator = SubscriptIterator< BasicEliasFano , std::uint64_t >;
 using iterator = const_iterator;

 [[nodiscard]] const_iterator begin( void ) const {
  return( const_iterator( this , 0 ) );
  }
 [[nodiscard]] const_iterator end( void ) const {
  return( const_iterator( this , f_n ) );
  }
 [[nodiscard]] const_iterator cbegin( void ) const { return( begin() ); }
 [[nodiscard]] const_iterator cend( void ) const { return( end() ); }

/*--------------------------------------------------------------------------*/
 private:

 [[nodiscard]] std::uint64_t bucket( std::uint64_t x ) const;

 std::size_t f_n = 0;
 std::uint64_t f_u = 0;
 int f_l = 0;
 BitVector f_low;
 BasicRankSelect< Lazy > f_high;

 };  // end( class BasicEliasFano )

using EliasFano = BasicEliasFano< false >;

using LazyEliasFano = BasicEliasFano< true >;

/*--------------------------------------------------------------------------*/

}  // end( namespace ADS )

/*--------------------------------------------------------------------------*/
/*-------------------------- IMPLEMENTATION --------------------------------*/
/*--------------------------------------------------------------------------*/

#include "ADS/succinct/impl/EliasFano.tpp"

/*--------------------------------------------------------------------------*/

#endif  /* EliasFano.h included */

/*--------------------------------------------------------------------------*/
/*-------------------------- End File EliasFano.h --------------------------*/
/*--------------------------------------------------------------------------*/