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//----------------------------------------------------------------------------
/// @file flat_stable_sort.hpp
/// @brief Flat stable sort algorithm
///
/// @author Copyright (c) 2017 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_FLAT_STABLE_SORT_HPP
#define __BOOST_SORT_FLAT_STABLE_SORT_HPP
#include <boost/sort/insert_sort/insert_sort.hpp>
#include <boost/sort/common/util/insert.hpp>
#include <boost/sort/common/merge_block.hpp>
#include <boost/sort/common/sort_basic.hpp>
#include <boost/sort/common/range.hpp>
#include <boost/sort/common/util/traits.hpp>
#include <boost/sort/common/indirect.hpp>
#include <cstdlib>
#include <functional>
#include <iterator>
#include <memory>
#include <type_traits>
#include <vector>
namespace boost
{
namespace sort
{
namespace flat_internal
{
namespace bsc = boost::sort::common;
namespace bscu = boost::sort::common::util;
//---------------------------------------------------------------------------
/// @struct flat_stable_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 = bscu::compare_iter<Iter_t>,
uint32_t Power2 = 10>
class flat_stable_sort: public bsc::merge_block<Iter_t, Compare, Power2>
{
//------------------------------------------------------------------------
// DEFINITIONS AND CONSTANTS
//------------------------------------------------------------------------
typedef bsc::merge_block<Iter_t, Compare, Power2> merge_block_t;
//-------------------------------------------------------------------------
// D E F I N I T I O N S
//-------------------------------------------------------------------------
typedef typename merge_block_t::value_t value_t;
typedef typename merge_block_t::range_pos range_pos;
typedef typename merge_block_t::range_it range_it;
typedef typename merge_block_t::range_buf range_buf;
typedef typename merge_block_t::it_index it_index;
typedef typename merge_block_t::circular_t circular_t;
//------------------------------------------------------------------------
// CONSTANTS
//------------------------------------------------------------------------
using merge_block_t::BLOCK_SIZE;
using merge_block_t::LOG_BLOCK;
using merge_block_t::index;
using merge_block_t::cmp;
using merge_block_t::ptr_circ;
using merge_block_t::get_range;
using merge_block_t::get_group_range;
using merge_block_t::merge_range_pos;
using merge_block_t::move_range_pos_backward;
using merge_block_t::rearrange_with_index;
public:
//------------------------------------------------------------------------
// PUBLIC FUNCTIONS
//-------------------------------------------------------------------------
flat_stable_sort(Iter_t first, Iter_t last, Compare comp,
circular_t *ptr_circ)
: merge_block_t(first, last, comp, ptr_circ)
{
divide(index.begin(), index.end());
rearrange_with_index();
};
flat_stable_sort(Iter_t first, Iter_t last, Compare comp = Compare())
: flat_stable_sort(first, last, comp, nullptr) { };
void divide(it_index itx_first, it_index itx_last);
void sort_small(it_index itx_first, it_index itx_last);
bool is_sorted_forward(it_index itx_first, it_index itx_last);
bool is_sorted_backward(it_index itx_first, it_index itx_last);
};
//----------------------------------------------------------------------------
// End of class flat_stable_sort
//----------------------------------------------------------------------------
//
//------------------------------------------------------------------------
// function :
/// @brief :
/// @param Pos :
/// @return
//------------------------------------------------------------------------
template <class Iter_t, typename Compare, uint32_t Power2>
void flat_stable_sort <Iter_t, Compare, Power2>
::divide(it_index itx_first, it_index itx_last)
{
size_t nblock = size_t(itx_last - itx_first);
if (nblock < 5)
{ sort_small(itx_first, itx_last);
return;
};
if ( nblock > 7)
{ if (is_sorted_forward(itx_first, itx_last)) return;
if (is_sorted_backward(itx_first, itx_last)) return;
};
size_t nblock1 = (nblock + 1) >> 1;
divide(itx_first, itx_first + nblock1);
divide(itx_first + nblock1, itx_last);
merge_range_pos(itx_first, itx_first + nblock1, itx_last);
};
//
//------------------------------------------------------------------------
// function : sort_small
/// @brief :
/// @param
/// @param
/// @param
//------------------------------------------------------------------------
template <class Iter_t, typename Compare, uint32_t Power2>
void flat_stable_sort <Iter_t, Compare, Power2>
::sort_small(it_index itx_first, it_index itx_last)
{
size_t nblock = size_t(itx_last - itx_first);
assert(nblock > 0 and nblock < 5);
value_t *paux = ptr_circ->get_buffer();
range_it rng_data = get_group_range(*itx_first, nblock);
if (nblock < 3)
{
range_buf rng_aux(paux, paux + rng_data.size());
range_sort_data(rng_data, rng_aux, cmp);
return;
};
//--------------------------------------------------------------------
// division of range_data in two ranges for be sorted and merged
//--------------------------------------------------------------------
size_t nblock1 = (nblock + 1) >> 1;
range_it rng_data1 = get_group_range(*itx_first, nblock1);
range_it rng_data2(rng_data1.last, rng_data.last);
range_buf rng_aux1(paux, paux + rng_data1.size());
range_buf rng_aux2(paux, paux + rng_data2.size());
range_sort_data(rng_data2, rng_aux2, cmp);
range_sort_buffer(rng_data1, rng_aux1, cmp);
merge_half(rng_data, rng_aux1, rng_data2, cmp);
};
//
//------------------------------------------------------------------------
// function : is_sorted_forward
/// @brief : return if the data are ordered,
/// @param itx_first : iterator to the first block in the index
/// @param itx_last : iterator to the last block in the index
/// @return : true : the data are ordered false : not ordered
//------------------------------------------------------------------------
template <class Iter_t, typename Compare, uint32_t Power2>
bool flat_stable_sort <Iter_t, Compare, Power2>
::is_sorted_forward(it_index itx_first, it_index itx_last)
{
size_t nblock = size_t(itx_last - itx_first);
range_it rng = get_group_range(*itx_first, nblock);
size_t nelem = rng.size();
size_t min_process = (std::max)(BLOCK_SIZE, (nelem >> 3));
size_t nsorted1 = bsc::number_stable_sorted_forward (rng.first, rng.last,
min_process, cmp);
if (nsorted1 == nelem) return true;
if (nsorted1 == 0) return false;
size_t nsorted2 = nelem - nsorted1;
Iter_t itaux = rng.first + nsorted1;
if (nsorted2 <= (BLOCK_SIZE << 1))
{
flat_stable_sort(itaux, rng.last, cmp, ptr_circ);
bscu::insert_sorted(rng.first, itaux, rng.last, cmp,
ptr_circ->get_buffer());
}
else
{ // Adjust the size of the sorted data to a number of blocks
size_t mask = ~(BLOCK_SIZE - 1);
size_t nsorted1_adjust = nsorted1 & mask;
flat_stable_sort(rng.first + nsorted1_adjust, rng.last, cmp,
ptr_circ);
size_t nblock1 = nsorted1_adjust >> Power2;
merge_range_pos(itx_first, itx_first + nblock1, itx_last);
};
return true;
};
//
//------------------------------------------------------------------------
// function : is_sorted_backward
/// @brief : return if the data are ordered,
/// @param itx_first : iterator to the first block in the index
/// @param itx_last : iterator to the last block in the index
/// @return : true : the data are ordered false : not ordered
//------------------------------------------------------------------------
template <class Iter_t, typename Compare, uint32_t Power2>
bool flat_stable_sort <Iter_t, Compare, Power2>
::is_sorted_backward(it_index itx_first, it_index itx_last)
{
size_t nblock = size_t(itx_last - itx_first);
range_it rng = get_group_range(*itx_first, nblock);
size_t nelem = rng.size();
size_t min_process = (std::max)(BLOCK_SIZE, (nelem >> 3));
size_t nsorted2 = bsc::number_stable_sorted_backward(rng.first, rng.last,
min_process, cmp);
if (nsorted2 == nelem) return true;
if (nsorted2 == 0 ) return false;
Iter_t itaux = rng.last - nsorted2;
size_t nsorted1 = nelem - nsorted2;
if (nsorted1 <= (BLOCK_SIZE << 1))
{
flat_stable_sort(rng.first, itaux, cmp, ptr_circ);
bscu::insert_sorted_backward(rng.first, itaux, rng.last, cmp,
ptr_circ->get_buffer());
}
else
{ // Adjust the size of nsorted2 for to be a number of blocks
size_t nblock1 = (nsorted1 + BLOCK_SIZE - 1) >> Power2;
size_t nsorted1_adjust = (nblock1 << Power2);
flat_stable_sort(rng.first, rng.first + nsorted1_adjust, cmp,
ptr_circ);
merge_range_pos(itx_first, itx_first + nblock1, itx_last);
};
return true;
};
//****************************************************************************
};// End namespace flat_internal
//****************************************************************************
//
namespace bscu = boost::sort::common::util;
namespace flat = boost::sort::flat_internal;
//
///---------------------------------------------------------------------------
// function flat_stable_sort
/// @brief This class is select the block size in the block_indirect_sort
/// algorithm depending of the type and size of the data to sort
///
//----------------------------------------------------------------------------
template <class Iter_t, class Compare = bscu::compare_iter<Iter_t>,
bscu::enable_if_string<value_iter<Iter_t> > * = nullptr>
inline void flat_stable_sort (Iter_t first, Iter_t last,
Compare cmp = Compare())
{
flat::flat_stable_sort<Iter_t, Compare, 6> (first, last, cmp);
};
template<size_t Size>
struct block_size_fss
{
static constexpr const uint32_t BitsSize =
(Size == 0) ? 0 : (Size > 128) ? 7 : bscu::tmsb[Size - 1];
static constexpr const uint32_t sz[10] =
{ 10, 10, 10, 9, 8, 7, 6, 6 };
static constexpr const uint32_t data = sz[BitsSize];
};
//
///---------------------------------------------------------------------------
// function flat_stable_sort
/// @brief This class is select the block size in the flat_stable_sort
/// algorithm depending of the type and size of the data to sort
///
//----------------------------------------------------------------------------
template <class Iter_t, class Compare = bscu::compare_iter<Iter_t>,
bscu::enable_if_not_string<value_iter<Iter_t> >* = nullptr>
inline void flat_stable_sort (Iter_t first, Iter_t last,
Compare cmp = Compare())
{
flat::flat_stable_sort<Iter_t, Compare,
block_size_fss<sizeof(value_iter<Iter_t> )>::data>
(first, last, cmp);
};
template<class Iter_t, class Compare = compare_iter<Iter_t> >
inline void indirect_flat_stable_sort (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 ( flat_stable_sort<itx_iter, itx_comp>,
first, last, comp);
};
//****************************************************************************
};// End namespace sort
};// End namepspace boost
//****************************************************************************
//
#endif
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