318 lines
14 KiB
C++
318 lines
14 KiB
C++
// Boost.Geometry Index
|
|
//
|
|
// R-tree quadratic split algorithm implementation
|
|
//
|
|
// Copyright (c) 2011-2015 Adam Wulkiewicz, Lodz, Poland.
|
|
//
|
|
// This file was modified by Oracle on 2019.
|
|
// Modifications copyright (c) 2019 Oracle and/or its affiliates.
|
|
// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
|
|
//
|
|
// Use, modification and distribution is subject to the Boost Software License,
|
|
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
|
|
|
#ifndef BOOST_GEOMETRY_INDEX_DETAIL_RTREE_QUADRATIC_REDISTRIBUTE_ELEMENTS_HPP
|
|
#define BOOST_GEOMETRY_INDEX_DETAIL_RTREE_QUADRATIC_REDISTRIBUTE_ELEMENTS_HPP
|
|
|
|
#include <algorithm>
|
|
|
|
#include <boost/core/ignore_unused.hpp>
|
|
|
|
#include <boost/geometry/index/detail/algorithms/content.hpp>
|
|
#include <boost/geometry/index/detail/algorithms/union_content.hpp>
|
|
|
|
#include <boost/geometry/index/detail/bounded_view.hpp>
|
|
|
|
#include <boost/geometry/index/detail/rtree/node/node.hpp>
|
|
#include <boost/geometry/index/detail/rtree/visitors/insert.hpp>
|
|
#include <boost/geometry/index/detail/rtree/visitors/is_leaf.hpp>
|
|
|
|
namespace boost { namespace geometry { namespace index {
|
|
|
|
namespace detail { namespace rtree {
|
|
|
|
namespace quadratic {
|
|
|
|
template <typename Box, typename Elements, typename Parameters, typename Translator>
|
|
inline void pick_seeds(Elements const& elements,
|
|
Parameters const& parameters,
|
|
Translator const& tr,
|
|
size_t & seed1,
|
|
size_t & seed2)
|
|
{
|
|
typedef typename Elements::value_type element_type;
|
|
typedef typename rtree::element_indexable_type<element_type, Translator>::type indexable_type;
|
|
typedef Box box_type;
|
|
typedef typename index::detail::default_content_result<box_type>::type content_type;
|
|
typedef typename index::detail::strategy_type<Parameters>::type strategy_type;
|
|
typedef index::detail::bounded_view
|
|
<
|
|
indexable_type, box_type, strategy_type
|
|
> bounded_indexable_view;
|
|
|
|
const size_t elements_count = parameters.get_max_elements() + 1;
|
|
BOOST_GEOMETRY_INDEX_ASSERT(elements.size() == elements_count, "wrong number of elements");
|
|
BOOST_GEOMETRY_INDEX_ASSERT(2 <= elements_count, "unexpected number of elements");
|
|
|
|
strategy_type const& strategy = index::detail::get_strategy(parameters);
|
|
|
|
content_type greatest_free_content = 0;
|
|
seed1 = 0;
|
|
seed2 = 1;
|
|
|
|
for ( size_t i = 0 ; i < elements_count - 1 ; ++i )
|
|
{
|
|
for ( size_t j = i + 1 ; j < elements_count ; ++j )
|
|
{
|
|
indexable_type const& ind1 = rtree::element_indexable(elements[i], tr);
|
|
indexable_type const& ind2 = rtree::element_indexable(elements[j], tr);
|
|
|
|
box_type enlarged_box;
|
|
index::detail::bounds(ind1, enlarged_box, strategy);
|
|
index::detail::expand(enlarged_box, ind2, strategy);
|
|
|
|
bounded_indexable_view bounded_ind1(ind1, strategy);
|
|
bounded_indexable_view bounded_ind2(ind2, strategy);
|
|
content_type free_content = ( index::detail::content(enlarged_box)
|
|
- index::detail::content(bounded_ind1) )
|
|
- index::detail::content(bounded_ind2);
|
|
|
|
if ( greatest_free_content < free_content )
|
|
{
|
|
greatest_free_content = free_content;
|
|
seed1 = i;
|
|
seed2 = j;
|
|
}
|
|
}
|
|
}
|
|
|
|
::boost::ignore_unused(parameters);
|
|
}
|
|
|
|
} // namespace quadratic
|
|
|
|
template <typename MembersHolder>
|
|
struct redistribute_elements<MembersHolder, quadratic_tag>
|
|
{
|
|
typedef typename MembersHolder::box_type box_type;
|
|
typedef typename MembersHolder::parameters_type parameters_type;
|
|
typedef typename MembersHolder::translator_type translator_type;
|
|
typedef typename MembersHolder::allocators_type allocators_type;
|
|
|
|
typedef typename MembersHolder::node node;
|
|
typedef typename MembersHolder::internal_node internal_node;
|
|
typedef typename MembersHolder::leaf leaf;
|
|
|
|
typedef typename index::detail::default_content_result<box_type>::type content_type;
|
|
|
|
template <typename Node>
|
|
static inline void apply(Node & n,
|
|
Node & second_node,
|
|
box_type & box1,
|
|
box_type & box2,
|
|
parameters_type const& parameters,
|
|
translator_type const& translator,
|
|
allocators_type & allocators)
|
|
{
|
|
typedef typename rtree::elements_type<Node>::type elements_type;
|
|
typedef typename elements_type::value_type element_type;
|
|
typedef typename rtree::element_indexable_type<element_type, translator_type>::type indexable_type;
|
|
|
|
elements_type & elements1 = rtree::elements(n);
|
|
elements_type & elements2 = rtree::elements(second_node);
|
|
|
|
BOOST_GEOMETRY_INDEX_ASSERT(elements1.size() == parameters.get_max_elements() + 1, "unexpected elements number");
|
|
|
|
// copy original elements - use in-memory storage (std::allocator)
|
|
// TODO: move if noexcept
|
|
typedef typename rtree::container_from_elements_type<elements_type, element_type>::type
|
|
container_type;
|
|
container_type elements_copy(elements1.begin(), elements1.end()); // MAY THROW, STRONG (alloc, copy)
|
|
container_type elements_backup(elements1.begin(), elements1.end()); // MAY THROW, STRONG (alloc, copy)
|
|
|
|
// calculate initial seeds
|
|
size_t seed1 = 0;
|
|
size_t seed2 = 0;
|
|
quadratic::pick_seeds<box_type>(elements_copy, parameters, translator, seed1, seed2);
|
|
|
|
// prepare nodes' elements containers
|
|
elements1.clear();
|
|
BOOST_GEOMETRY_INDEX_ASSERT(elements2.empty(), "second node's elements container should be empty");
|
|
|
|
BOOST_TRY
|
|
{
|
|
typename index::detail::strategy_type<parameters_type>::type const&
|
|
strategy = index::detail::get_strategy(parameters);
|
|
|
|
// add seeds
|
|
elements1.push_back(elements_copy[seed1]); // MAY THROW, STRONG (copy)
|
|
elements2.push_back(elements_copy[seed2]); // MAY THROW, STRONG (alloc, copy)
|
|
|
|
// calculate boxes
|
|
detail::bounds(rtree::element_indexable(elements_copy[seed1], translator),
|
|
box1, strategy);
|
|
detail::bounds(rtree::element_indexable(elements_copy[seed2], translator),
|
|
box2, strategy);
|
|
|
|
// remove seeds
|
|
if (seed1 < seed2)
|
|
{
|
|
rtree::move_from_back(elements_copy, elements_copy.begin() + seed2); // MAY THROW, STRONG (copy)
|
|
elements_copy.pop_back();
|
|
rtree::move_from_back(elements_copy, elements_copy.begin() + seed1); // MAY THROW, STRONG (copy)
|
|
elements_copy.pop_back();
|
|
}
|
|
else
|
|
{
|
|
rtree::move_from_back(elements_copy, elements_copy.begin() + seed1); // MAY THROW, STRONG (copy)
|
|
elements_copy.pop_back();
|
|
rtree::move_from_back(elements_copy, elements_copy.begin() + seed2); // MAY THROW, STRONG (copy)
|
|
elements_copy.pop_back();
|
|
}
|
|
|
|
// initialize areas
|
|
content_type content1 = index::detail::content(box1);
|
|
content_type content2 = index::detail::content(box2);
|
|
|
|
size_t remaining = elements_copy.size();
|
|
|
|
// redistribute the rest of the elements
|
|
while ( !elements_copy.empty() )
|
|
{
|
|
typename container_type::reverse_iterator el_it = elements_copy.rbegin();
|
|
bool insert_into_group1 = false;
|
|
|
|
size_t elements1_count = elements1.size();
|
|
size_t elements2_count = elements2.size();
|
|
|
|
// if there is small number of elements left and the number of elements in node is lesser than min_elems
|
|
// just insert them to this node
|
|
if ( elements1_count + remaining <= parameters.get_min_elements() )
|
|
{
|
|
insert_into_group1 = true;
|
|
}
|
|
else if ( elements2_count + remaining <= parameters.get_min_elements() )
|
|
{
|
|
insert_into_group1 = false;
|
|
}
|
|
// insert the best element
|
|
else
|
|
{
|
|
// find element with minimum groups areas increses differences
|
|
content_type content_increase1 = 0;
|
|
content_type content_increase2 = 0;
|
|
el_it = pick_next(elements_copy.rbegin(), elements_copy.rend(),
|
|
box1, box2, content1, content2,
|
|
translator, strategy,
|
|
content_increase1, content_increase2);
|
|
|
|
if ( content_increase1 < content_increase2 ||
|
|
( content_increase1 == content_increase2 && ( content1 < content2 ||
|
|
( content1 == content2 && elements1_count <= elements2_count ) )
|
|
) )
|
|
{
|
|
insert_into_group1 = true;
|
|
}
|
|
else
|
|
{
|
|
insert_into_group1 = false;
|
|
}
|
|
}
|
|
|
|
// move element to the choosen group
|
|
element_type const& elem = *el_it;
|
|
indexable_type const& indexable = rtree::element_indexable(elem, translator);
|
|
|
|
if ( insert_into_group1 )
|
|
{
|
|
elements1.push_back(elem); // MAY THROW, STRONG (copy)
|
|
index::detail::expand(box1, indexable, strategy);
|
|
content1 = index::detail::content(box1);
|
|
}
|
|
else
|
|
{
|
|
elements2.push_back(elem); // MAY THROW, STRONG (alloc, copy)
|
|
index::detail::expand(box2, indexable, strategy);
|
|
content2 = index::detail::content(box2);
|
|
}
|
|
|
|
BOOST_GEOMETRY_INDEX_ASSERT(!elements_copy.empty(), "expected more elements");
|
|
typename container_type::iterator el_it_base = el_it.base();
|
|
rtree::move_from_back(elements_copy, --el_it_base); // MAY THROW, STRONG (copy)
|
|
elements_copy.pop_back();
|
|
|
|
BOOST_GEOMETRY_INDEX_ASSERT(0 < remaining, "expected more remaining elements");
|
|
--remaining;
|
|
}
|
|
}
|
|
BOOST_CATCH(...)
|
|
{
|
|
//elements_copy.clear();
|
|
elements1.clear();
|
|
elements2.clear();
|
|
|
|
rtree::destroy_elements<MembersHolder>::apply(elements_backup, allocators);
|
|
//elements_backup.clear();
|
|
|
|
BOOST_RETHROW // RETHROW, BASIC
|
|
}
|
|
BOOST_CATCH_END
|
|
}
|
|
|
|
// TODO: awulkiew - change following function to static member of the pick_next class?
|
|
|
|
template <typename It>
|
|
static inline It pick_next(It first, It last,
|
|
box_type const& box1, box_type const& box2,
|
|
content_type const& content1, content_type const& content2,
|
|
translator_type const& translator,
|
|
typename index::detail::strategy_type<parameters_type>::type const& strategy,
|
|
content_type & out_content_increase1, content_type & out_content_increase2)
|
|
{
|
|
typedef typename boost::iterator_value<It>::type element_type;
|
|
typedef typename rtree::element_indexable_type<element_type, translator_type>::type indexable_type;
|
|
|
|
content_type greatest_content_incrase_diff = 0;
|
|
It out_it = first;
|
|
out_content_increase1 = 0;
|
|
out_content_increase2 = 0;
|
|
|
|
// find element with greatest difference between increased group's boxes areas
|
|
for ( It el_it = first ; el_it != last ; ++el_it )
|
|
{
|
|
indexable_type const& indexable = rtree::element_indexable(*el_it, translator);
|
|
|
|
// calculate enlarged boxes and areas
|
|
box_type enlarged_box1(box1);
|
|
box_type enlarged_box2(box2);
|
|
index::detail::expand(enlarged_box1, indexable, strategy);
|
|
index::detail::expand(enlarged_box2, indexable, strategy);
|
|
content_type enlarged_content1 = index::detail::content(enlarged_box1);
|
|
content_type enlarged_content2 = index::detail::content(enlarged_box2);
|
|
|
|
content_type content_incrase1 = (enlarged_content1 - content1);
|
|
content_type content_incrase2 = (enlarged_content2 - content2);
|
|
|
|
content_type content_incrase_diff = content_incrase1 < content_incrase2 ?
|
|
content_incrase2 - content_incrase1 : content_incrase1 - content_incrase2;
|
|
|
|
if ( greatest_content_incrase_diff < content_incrase_diff )
|
|
{
|
|
greatest_content_incrase_diff = content_incrase_diff;
|
|
out_it = el_it;
|
|
out_content_increase1 = content_incrase1;
|
|
out_content_increase2 = content_incrase2;
|
|
}
|
|
}
|
|
|
|
return out_it;
|
|
}
|
|
};
|
|
|
|
}} // namespace detail::rtree
|
|
|
|
}}} // namespace boost::geometry::index
|
|
|
|
#endif // BOOST_GEOMETRY_INDEX_DETAIL_RTREE_QUADRATIC_REDISTRIBUTE_ELEMENTS_HPP
|