Added thirdparty: boost library

thirdparty/include/boost/geometry/index/detail/rtree/utilities/statistics.hpp

@@ -0,0 +1,112 @@
+// Boost.Geometry Index
+//
+// R-tree visitor collecting basic statistics
+//
+// Copyright (c) 2011-2013 Adam Wulkiewicz, Lodz, Poland.
+// Copyright (c) 2013 Mateusz Loskot, London, UK.
+//
+// This file was modified by Oracle on 2019-2023.
+// Modifications copyright (c) 2019-2023 Oracle and/or its affiliates.
+// Contributed and/or modified by Vissarion Fysikopoulos, on behalf of Oracle
+// 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_UTILITIES_STATISTICS_HPP
+#define BOOST_GEOMETRY_INDEX_DETAIL_RTREE_UTILITIES_STATISTICS_HPP
+
+#include <algorithm>
+#include <tuple>
+
+#include <boost/geometry/index/detail/rtree/node/node_elements.hpp>
+#include <boost/geometry/index/detail/rtree/node/variant_visitor.hpp>
+#include <boost/geometry/index/detail/rtree/utilities/view.hpp>
+
+namespace boost { namespace geometry { namespace index { namespace detail { namespace rtree { namespace utilities {
+
+namespace visitors {
+
+template <typename MembersHolder>
+struct statistics
+    : public MembersHolder::visitor_const
+{
+    typedef typename MembersHolder::internal_node internal_node;
+    typedef typename MembersHolder::leaf leaf;
+
+    inline statistics()
+        : level(0)
+        , levels(1) // count root
+        , nodes(0)
+        , leaves(0)
+        , values(0)
+        , values_min(0)
+        , values_max(0)
+    {}
+
+    inline void operator()(internal_node const& n)
+    {
+        typedef typename rtree::elements_type<internal_node>::type elements_type;
+        elements_type const& elements = rtree::elements(n);
+
+        ++nodes; // count node
+
+        size_t const level_backup = level;
+        ++level;
+
+        levels += level++ > levels ? 1 : 0; // count level (root already counted)
+
+        for (typename elements_type::const_iterator it = elements.begin();
+            it != elements.end(); ++it)
+        {
+            rtree::apply_visitor(*this, *it->second);
+        }
+
+        level = level_backup;
+    }
+
+    inline void operator()(leaf const& n)
+    {
+        typedef typename rtree::elements_type<leaf>::type elements_type;
+        elements_type const& elements = rtree::elements(n);
+
+        ++leaves; // count leaves
+
+        std::size_t const v = elements.size();
+        // count values spread per node and total
+        values_min = (std::min)(values_min == 0 ? v : values_min, v);
+        values_max = (std::max)(values_max, v);
+        values += v;
+    }
+
+    std::size_t level;
+    std::size_t levels;
+    std::size_t nodes;
+    std::size_t leaves;
+    std::size_t values;
+    std::size_t values_min;
+    std::size_t values_max;
+};
+
+} // namespace visitors
+
+template <typename Rtree> inline
+std::tuple<std::size_t, std::size_t, std::size_t, std::size_t, std::size_t, std::size_t>
+statistics(Rtree const& tree)
+{
+    typedef utilities::view<Rtree> RTV;
+    RTV rtv(tree);
+
+    visitors::statistics<
+        typename RTV::members_holder
+    > stats_v;
+
+    rtv.apply_visitor(stats_v);
+
+    return std::make_tuple(stats_v.levels, stats_v.nodes, stats_v.leaves, stats_v.values, stats_v.values_min, stats_v.values_max);
+}
+
+}}}}}} // namespace boost::geometry::index::detail::rtree::utilities
+
+#endif // BOOST_GEOMETRY_INDEX_DETAIL_RTREE_UTILITIES_STATISTICS_HPP