[index][utilities] Add are_counts_ok().

2025-05-11 13:34:10 +00:00 · 2015-01-07 22:42:48 +01:00 · 2015-01-07 22:42:48 +01:00 · 416ec8423c
commit 416ec8423c
parent 69d03e9a7c
1 changed files with 110 additions and 0 deletions
--- a/include/boost/geometry/index/detail/rtree/utilities/are_counts_ok.hpp
+++ b/include/boost/geometry/index/detail/rtree/utilities/are_counts_ok.hpp
@ -0,0 +1,110 @@
+// Boost.Geometry Index
+//
+// R-tree nodes elements numbers validating visitor implementation
+//
+// Copyright (c) 2011-2015 Adam Wulkiewicz, Lodz, Poland.
+//
+// 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_ARE_COUNTS_OK_HPP
+#define BOOST_GEOMETRY_INDEX_DETAIL_RTREE_UTILITIES_ARE_COUNTS_OK_HPP
+
+#include <boost/geometry/index/detail/rtree/node/node.hpp>
+
+namespace boost { namespace geometry { namespace index { namespace detail { namespace rtree { namespace utilities {
+
+namespace visitors {
+
+template <typename Value, typename Options, typename Box, typename Allocators>
+class are_counts_ok
+    : public rtree::visitor<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag, true>::type
+{
+    typedef typename rtree::internal_node<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type internal_node;
+    typedef typename rtree::leaf<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type leaf;
+    typedef typename Options::parameters_type parameters_type;
+
+public:
+    inline are_counts_ok(parameters_type const& parameters)
+        : result(true), m_current_level(0), m_parameters(parameters)
+    {}
+
+    inline void operator()(internal_node const& n)
+    {
+        typedef typename rtree::elements_type<internal_node>::type elements_type;
+        elements_type const& elements = rtree::elements(n);
+
+        // root internal node shouldn't contain 0 elements
+        if ( elements.empty()
+          || !check_count(elements) )
+        {
+            result = false;
+            return;
+        }
+
+        size_t current_level_backup = m_current_level;
+        ++m_current_level;
+
+        for ( typename elements_type::const_iterator it = elements.begin();
+              it != elements.end() && result == true ;
+              ++it)
+        {
+            rtree::apply_visitor(*this, *it->second);
+        }
+
+        m_current_level = current_level_backup;
+    }
+
+    inline void operator()(leaf const& n)
+    {
+        typedef typename rtree::elements_type<leaf>::type elements_type;
+        elements_type const& elements = rtree::elements(n);
+
+        // empty leaf in non-root node
+        if ( ( m_current_level > 0 && elements.empty() )
+          || !check_count(elements) )
+        {
+            result = false;
+        }
+    }
+
+    bool result;
+
+private:
+    template <typename Elements>
+    bool check_count(Elements const& elements)
+    {
+        // root may contain count < min but should never contain count > max
+        return elements.size() <= m_parameters.get_max_elements()
+            && ( elements.size() >= m_parameters.get_min_elements()
+              || m_current_level == 0 );
+    }
+
+    size_t m_current_level;
+    parameters_type const& m_parameters;
+};
+
+} // namespace visitors
+
+template <typename Rtree> inline
+bool are_counts_ok(Rtree const& tree)
+{
+    typedef utilities::view<Rtree> RTV;
+    RTV rtv(tree);
+
+    visitors::are_counts_ok<
+        typename RTV::value_type,
+        typename RTV::options_type,
+        typename RTV::box_type,
+        typename RTV::allocators_type
+    > v(tree.parameters());
+    
+    rtv.apply_visitor(v);
+
+    return v.result;
+}
+
+}}}}}} // namespace boost::geometry::index::detail::rtree::utilities
+
+#endif // BOOST_GEOMETRY_INDEX_DETAIL_RTREE_UTILITIES_ARE_COUNTS_OK_HPP