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//----------------------------------------------------------------------------
/// @file spinsort.hpp
/// @brief Spin Sort algorithm
///
/// @author Copyright (c) 2016 Francisco José Tapia (fjtapia@gmail.com )\n
/// Distributed under the Boost Software License, Version 1.0.\n
/// ( See accompanying file LICENSE_1_0.txt or copy at
/// http://www.boost.org/LICENSE_1_0.txt )
/// @version 0.1
///
/// @remarks
//-----------------------------------------------------------------------------
#ifndef __BOOST_SORT_PARALLEL_ALGORITHM_SPIN_SORT_HPP
#define __BOOST_SORT_PARALLEL_ALGORITHM_SPIN_SORT_HPP
#include <ciso646>
#include <cstdlib>
#include <functional>
#include <iterator>
#include <memory>
#include <type_traits>
#include <vector>
#include <cstddef>
#include <boost/sort/insert_sort/insert_sort.hpp>
#include <boost/sort/common/util/traits.hpp>
#include <boost/sort/common/util/algorithm.hpp>
#include <boost/sort/common/range.hpp>
#include <boost/sort/common/indirect.hpp>
namespace boost
{
namespace sort
{
namespace spin_detail
{
//----------------------------------------------------------------------------
// USING SENTENCES
//----------------------------------------------------------------------------
namespace bsc = boost::sort::common;
using bsc::range;
using bsc::util::nbits64;
using bsc::util::compare_iter;
using bsc::util::value_iter;
using boost::sort::insert_sort;
//
//############################################################################
// ##
// D E F I N I T I O N S O F F U N C T I O N S ##
// ##
//############################################################################
//
template <class Iter1_t, class Iter2_t, typename Compare>
static void insert_partial_sort (Iter1_t first, Iter1_t mid,
Iter1_t last, Compare comp,
const range<Iter2_t> &rng_aux);
template<class Iter1_t, class Iter2_t, class Compare>
static bool check_stable_sort (const range<Iter1_t> &rng_data,
const range<Iter2_t> &rng_aux, Compare comp);
template<class Iter1_t, class Iter2_t, class Compare>
static void range_sort (const range<Iter1_t> &range1,
const range<Iter2_t> &range2, Compare comp,
uint32_t level);
template<class Iter1_t, class Iter2_t, class Compare>
static void sort_range_sort (const range<Iter1_t> &rng_data,
const range<Iter2_t> &rng_aux, Compare comp);
//
//-----------------------------------------------------------------------------
// function : insert_partial_sort
/// @brief : Insertion sort of elements sorted
/// @param first: iterator to the first element of the range
/// @param mid : last pointer of the sorted data, and first pointer to the
/// elements to insert
/// @param last : iterator to the next element of the last in the range
/// @param comp :
/// @comments : the two ranges are sorted
//-----------------------------------------------------------------------------
template<class Iter1_t, class Iter2_t, typename Compare>
static void insert_partial_sort (Iter1_t first, Iter1_t mid, Iter1_t last,
Compare comp, const range <Iter2_t> &rng_aux)
{
//------------------------------------------------------------------------
// metaprogram
//------------------------------------------------------------------------
typedef value_iter<Iter1_t> value_t;
typedef value_iter<Iter2_t> value2_t;
static_assert (std::is_same<value_t, value2_t>::value,
"Incompatible iterators\n");
//--------------------------------------------------------------------
// program
//--------------------------------------------------------------------
assert(size_t(last - mid) <= rng_aux.size());
if (mid == last) return;
//insertionsort ( mid, last, comp);
if (first == mid) return;
//------------------------------------------------------------------------
// creation of the vector of elements to insert and their position in the
// sorted part
// the data are inserted in rng_aux
//-----------------------------------------------------------------------
std::vector<Iter1_t> viter;
Iter2_t beta = rng_aux.first, data = rng_aux.first;
for (Iter1_t alpha = mid; alpha != last; ++alpha)
*(beta++) = std::move(*alpha);
size_t ndata = last - mid;
Iter1_t linf = first, lsup = mid;
for (uint32_t i = 0; i < ndata; ++i)
{
Iter1_t it1 = std::upper_bound(linf, lsup, *(data + i), comp);
viter.push_back(it1);
linf = it1;
};
// moving the elements
viter.push_back(mid);
for (uint32_t i = viter.size() - 1; i != 0; --i)
{
Iter1_t src = viter[i], limit = viter[i - 1];
Iter1_t dest = src + (i);
while (src != limit) *(--dest) = std::move(*(--src));
*(viter[i - 1] + (i - 1)) = std::move(*(data + (i - 1)));
};
}
;
//-----------------------------------------------------------------------------
// function : check_stable_sort
/// @brief check if the elements between first and last are osted or reverse
/// sorted. If the number of elements not sorted is small, insert in
/// the sorted part
/// @param range_input : range with the elements to sort
/// @param range_buffer : range with the elements sorted
/// @param comp : object for to compare two elements
/// @param level : when is 1, sort with the insertionsort algorithm
/// if not make a recursive call splitting the ranges
//
/// @comments : if the number of levels is odd, the data are in the first
/// parameter of range_sort, and the results appear in the second parameter
/// If the number of levels is even, the data are in the second
/// parameter of range_sort, and the results are in the same parameter
//-----------------------------------------------------------------------------
template<class Iter1_t, class Iter2_t, class Compare>
static bool check_stable_sort(const range<Iter1_t> &rng_data,
const range<Iter2_t> &rng_aux, Compare comp)
{
//------------------------------------------------------------------------
// metaprogramming
//------------------------------------------------------------------------
typedef value_iter<Iter1_t> value_t;
typedef value_iter<Iter2_t> value2_t;
static_assert (std::is_same<value_t, value2_t>::value,
"Incompatible iterators\n");
//------------------------------------------------------------------------
// program
//------------------------------------------------------------------------
// the maximun number of elements not ordered, for to be inserted in the
// sorted part
//const ptrdiff_t min_insert_partial_sort = 32 ;
const size_t ndata = rng_data.size();
if (ndata < 32)
{
insert_sort(rng_data.first, rng_data.last, comp);
return true;
};
const size_t min_insert_partial_sort =
((ndata >> 3) < 33) ? 32 : (ndata >> 3);
if (ndata < 2) return true;
// check if sorted
bool sw = true;
Iter1_t it2 = rng_data.first + 1;
for (Iter1_t it1 = rng_data.first;
it2 != rng_data.last and (sw = not comp(*it2, *it1)); it1 =
it2++)
;
if (sw) return true;
// insert the elements between it1 and last
if (size_t(rng_data.last - it2) < min_insert_partial_sort)
{
sort_range_sort(range<Iter1_t>(it2, rng_data.last), rng_aux, comp);
insert_partial_sort(rng_data.first, it2, rng_data.last, comp, rng_aux);
return true;
};
// check if reverse sorted
if ((it2 != (rng_data.first + 1))) return false;
sw = true;
for (Iter1_t it1 = rng_data.first;
it2 != rng_data.last and (sw = comp(*it2, *it1)); it1 =
it2++)
;
if (size_t(rng_data.last - it2) >= min_insert_partial_sort) return false;
// reverse the elements between first and it1
size_t nreverse = it2 - rng_data.first;
Iter1_t alpha(rng_data.first), beta(it2 - 1), mid(
rng_data.first + (nreverse >> 1));
while (alpha != mid) {
using std::swap;
swap(*(alpha++), *(beta--));
}
// insert the elements between it1 and last
if (it2 != rng_data.last)
{
sort_range_sort(range<Iter1_t>(it2, rng_data.last), rng_aux, comp);
insert_partial_sort(rng_data.first, it2, rng_data.last, comp, rng_aux);
};
return true;
}
;
//-----------------------------------------------------------------------------
// function : range_sort
/// @brief this function divide r_input in two parts, sort it,and merge moving
/// the elements to range_buf
/// @param range_input : range with the elements to sort
/// @param range_buffer : range with the elements sorted
/// @param comp : object for to compare two elements
/// @param level : when is 1, sort with the insertionsort algorithm
/// if not make a recursive call splitting the ranges
//
/// @comments : if the number of levels is odd, the data are in the first
/// parameter of range_sort, and the results appear in the second parameter
/// If the number of levels is even, the data are in the second
/// parameter of range_sort, and the results are in the same parameter
/// The two ranges must have the same size
//-----------------------------------------------------------------------------
template<class Iter1_t, class Iter2_t, class Compare>
static void range_sort(const range<Iter1_t> &range1,
const range<Iter2_t> &range2, Compare comp,
uint32_t level)
{
//-----------------------------------------------------------------------
// metaprogram
//-----------------------------------------------------------------------
typedef value_iter<Iter1_t> value_t;
typedef value_iter<Iter2_t> value2_t;
static_assert (std::is_same<value_t, value2_t>::value,
"Incompatible iterators\n");
//-----------------------------------------------------------------------
// program
//-----------------------------------------------------------------------
typedef range<Iter1_t> range_it1;
typedef range<Iter2_t> range_it2;
assert(range1.size() == range2.size() and level != 0);
//------------------- check if sort --------------------------------------
if (range1.size() > 1024)
{
if ((level & 1) == 0)
{
if (check_stable_sort(range2, range1, comp)) return;
}
else
{
if (check_stable_sort(range1, range2, comp))
{
move_forward(range2, range1);
return;
};
};
};
//------------------- normal process -----------------------------------
size_t nelem1 = (range1.size() + 1) >> 1;
range_it1 range_input1(range1.first, range1.first + nelem1),
range_input2(range1.first + nelem1, range1.last);
if (level < 2)
{
insert_sort(range_input1.first, range_input1.last, comp);
insert_sort(range_input2.first, range_input2.last, comp);
}
else
{
range_sort (range_it2(range2.first, range2.first + nelem1),
range_input1, comp, level - 1);
range_sort (range_it2(range2.first + nelem1, range2.last),
range_input2, comp, level - 1);
};
merge(range2, range_input1, range_input2, comp);
}
;
//-----------------------------------------------------------------------------
// function : sort_range_sort
/// @brief this sort elements using the range_sort function and receiving a
/// buffer of initialized memory
/// @param rng_data : range with the elements to sort
/// @param rng_aux : range of at least the same memory than rng_data used as
/// auxiliary memory in the sorting
/// @param comp : object for to compare two elements
//-----------------------------------------------------------------------------
template<class Iter1_t, class Iter2_t, class Compare>
static void sort_range_sort(const range<Iter1_t> &rng_data,
const range<Iter2_t> &rng_aux, Compare comp)
{
//-----------------------------------------------------------------------
// metaprogram
//-----------------------------------------------------------------------
typedef value_iter<Iter1_t> value_t;
typedef value_iter<Iter2_t> value2_t;
static_assert (std::is_same<value_t, value2_t>::value,
"Incompatible iterators\n");
//------------------------------------------------------------------------
// program
//------------------------------------------------------------------------
// minimal number of element before to jump to insertionsort
static const uint32_t sort_min = 32;
if (rng_data.size() <= sort_min)
{
insert_sort(rng_data.first, rng_data.last, comp);
return;
};
#ifdef __BS_DEBUG
assert (rng_aux.size () >= rng_data.size ());
#endif
range<Iter2_t> rng_buffer(rng_aux.first, rng_aux.first + rng_data.size());
uint32_t nlevel =
nbits64(((rng_data.size() + sort_min - 1) / sort_min) - 1);
//assert (nlevel != 0);
if ((nlevel & 1) == 0)
{
range_sort(rng_buffer, rng_data, comp, nlevel);
}
else
{
range_sort(rng_data, rng_buffer, comp, nlevel);
move_forward(rng_data, rng_buffer);
};
}
;
//
//############################################################################
// ##
// S T R U C T ##
// ##
// S P I N _ S O R T ##
// ##
//############################################################################
//---------------------------------------------------------------------------
/// @struct spin_sort
/// @brief This class implement s stable sort algorithm with 1 thread, with
/// an auxiliary memory of N/2 elements
//----------------------------------------------------------------------------
template<class Iter_t, typename Compare = compare_iter<Iter_t>>
class spinsort
{
//------------------------------------------------------------------------
// DEFINITIONS AND CONSTANTS
//------------------------------------------------------------------------
typedef value_iter<Iter_t> value_t;
typedef range<Iter_t> range_it;
typedef range<value_t *> range_buf;
// When the number of elements to sort is smaller than Sort_min, are sorted
// by the insertion sort algorithm
static const uint32_t Sort_min = 36;
//------------------------------------------------------------------------
// VARIABLES
//------------------------------------------------------------------------
// Pointer to the auxiliary memory
value_t *ptr;
// Number of elements in the auxiliary memory
size_t nptr;
// construct indicate if the auxiliary memory in initialized, and owner
// indicate if the auxiliary memory had been created inside the object or
// had
// been received as a parameter
bool construct = false, owner = false;
//------------------------------------------------------------------------
// PRIVATE FUNCTIONS
//-------------------------------------------------------------------------
spinsort (Iter_t first, Iter_t last, Compare comp, value_t *paux,
size_t naux);
public:
//------------------------------------------------------------------------
// PUBLIC FUNCTIONS
//-------------------------------------------------------------------------
spinsort(Iter_t first, Iter_t last, Compare comp = Compare())
: spinsort(first, last, comp, nullptr, 0) { };
spinsort(Iter_t first, Iter_t last, Compare comp, range_buf range_aux)
: spinsort(first, last, comp, range_aux.first, range_aux.size()) { };
//
//-----------------------------------------------------------------------
// function :~spinsort
/// @brief destructor of the struct. Destroy the elements if construct is
/// true,
/// and return the memory if owner is true
//-----------------------------------------------------------------------
~spinsort(void)
{
if (construct)
{
destroy(range<value_t *>(ptr, ptr + nptr));
construct = false;
};
if (owner and ptr != nullptr) std::free (ptr);
};
};
//----------------------------------------------------------------------------
// End of class spinsort
//----------------------------------------------------------------------------
//
//-------------------------------------------------------------------------
// function : spinsort
/// @brief constructor of the struct
//
/// @param first : iterator to the first element of the range to sort
/// @param last : iterator after the last element to the range to sort
/// @param comp : object for to compare two elements pointed by Iter_t
/// iterators
/// @param paux : pointer to the auxiliary memory provided. If nullptr, the
/// memory is created inside the class
/// @param naux : number of elements pointed by paux
//------------------------------------------------------------------------
template <class Iter_t, typename Compare>
spinsort <Iter_t, Compare>
::spinsort (Iter_t first, Iter_t last, Compare comp, value_t *paux, size_t naux)
: ptr(paux), nptr(naux), construct(false), owner(false)
{
range<Iter_t> range_input(first, last);
assert(range_input.valid());
size_t nelem = range_input.size();
owner = construct = false;
nptr = (nelem + 1) >> 1;
size_t nelem_1 = nptr;
size_t nelem_2 = nelem - nelem_1;
if (nelem <= (Sort_min << 1))
{
insert_sort(range_input.first, range_input.last, comp);
return;
};
//------------------- check if sort ---------------------------------
bool sw = true;
for (Iter_t it1 = first, it2 = first + 1; it2 != last
and (sw = not comp(*it2, *it1)); it1 = it2++) ;
if (sw) return;
//------------------- check if reverse sort -------------------------
sw = true;
for (Iter_t it1 = first, it2 = first + 1;
it2 != last and (sw = comp(*it2, *it1)); it1 = it2++);
if (sw)
{
using std::swap;
size_t nelem2 = nelem >> 1;
Iter_t it1 = first, it2 = last - 1;
for (size_t i = 0; i < nelem2; ++i)
swap(*(it1++), *(it2--));
return;
};
if (ptr == nullptr)
{
ptr = reinterpret_cast <value_t*>
(std::malloc (nptr * sizeof(value_t)));
if (ptr == nullptr) throw std::bad_alloc();
owner = true;
};
range_buf range_aux(ptr, (ptr + nptr));
//---------------------------------------------------------------------
// Process
//---------------------------------------------------------------------
uint32_t nlevel = nbits64(((nelem + Sort_min - 1) / Sort_min) - 1) - 1;
assert(nlevel != 0);
if ((nlevel & 1) == 1)
{
//----------------------------------------------------------------
// if the number of levels is odd, the data are in the first
// parameter of range_sort, and the results appear in the second
// parameter
//----------------------------------------------------------------
range_it range_1(first, first + nelem_2), range_2(first + nelem_2,
last);
range_aux = move_construct(range_aux, range_2);
construct = true;
range_sort(range_aux, range_2, comp, nlevel);
range_buf rng_bx(range_aux.first, range_aux.first + nelem_2);
range_sort(range_1, rng_bx, comp, nlevel);
merge_half(range_input, rng_bx, range_2, comp);
}
else
{
//----------------------------------------------------------------
// If the number of levels is even, the data are in the second
// parameter of range_sort, and the results are in the same
// parameter
//----------------------------------------------------------------
range_it range_1(first, first + nelem_1), range_2(first + nelem_1,
last);
range_aux = move_construct(range_aux, range_1);
construct = true;
range_sort(range_1, range_aux, comp, nlevel);
range_1.last = range_1.first + range_2.size();
range_sort(range_1, range_2, comp, nlevel);
merge_half(range_input, range_aux, range_2, comp);
};
};
//****************************************************************************
};// End namepspace spin_detail
//****************************************************************************
//
namespace bsc = boost::sort::common;
//-----------------------------------------------------------------------------
// function : spinsort
/// @brief this function implement a single thread stable sort
///
/// @param first : iterator to the first element of the range to sort
/// @param last : iterator after the last element to the range to sort
/// @param comp : object for to compare two elements pointed by Iter_t
/// iterators
//-----------------------------------------------------------------------------
template <class Iter_t, class Compare = compare_iter<Iter_t>>
inline void spinsort (Iter_t first, Iter_t last, Compare comp = Compare())
{
spin_detail::spinsort <Iter_t, Compare> (first, last, comp);
};
template <class Iter_t, class Compare = compare_iter<Iter_t>>
inline void indirect_spinsort (Iter_t first, Iter_t last,
Compare comp = Compare())
{
typedef typename std::vector<Iter_t>::iterator itx_iter;
typedef common::less_ptr_no_null <Iter_t, Compare> itx_comp;
common::indirect_sort (spinsort<itx_iter, itx_comp>, first, last, comp);
};
//****************************************************************************
};// End namespace sort
};// End namepspace boost
//****************************************************************************
//
#endif
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