Fastest way to remove items from Boost Rtree - c++

Question

I've tested the code from [1] to remove items from a Boost Rtree. However, it is quite slow. It takes about 1s to insert 1M records and 12s to remove them.
Can it be done faster?
Here is the test code:
#include <vector>
#include <iostream>
#include <stdio.h>
#include <boost/geometry.hpp>
#include <boost/geometry/index/rtree.hpp>
#include <boost/timer.hpp>
struct Rect
{
Rect() {}
Rect(int a_minX, int a_minY, int a_maxX, int a_maxY)
{
min[0] = a_minX;
min[1] = a_minY;
max[0] = a_maxX;
max[1] = a_maxY;
}
int min[2];
int max[2];
};
int main()
{
// randomize rectangles
std::vector<Rect> rects;
for (size_t i = 0 ; i < 1000000 ; ++i)
{
int min_x = rand() % 100000;
int min_y = rand() % 100000;
int w = 1 + rand() % 100;
int h = 1 + rand() % 100;
rects.push_back(Rect(min_x, min_y, min_x+w, min_y+h));
}
// create the rectangle passed into the query
Rect search_rect(4, 4, 6, 6);
// create the Boost.Geometry R-tree
namespace bg = boost::geometry;
namespace bgi = boost::geometry::index;
typedef bg::model::point<double, 2, bg::cs::cartesian> point_t;
typedef bg::model::box<point_t> box_t;
typedef std::pair<box_t, uint64_t> value_t;
bgi::rtree<value_t, bgi::quadratic<8,4> > bg_tree;
{
boost::timer t;
for(size_t i = 0; i < rects.size(); i++)
{
Rect const& r = rects[i];
box_t b(point_t(r.min[0], r.min[1]), point_t(r.max[0], r.max[1]));
bg_tree.insert(value_t(b, i));
}
double s = t.elapsed();
std::cout << s << " Boost insert time" << std::endl;
}
// test BG Rtree
{
std::vector<value_t> res;
box_t search_box(
point_t(search_rect.min[0], search_rect.min[1]),
point_t(search_rect.max[0], search_rect.max[1]));
size_t sum = 0;
boost::timer t;
for (size_t i = 0 ; i < 10000 ; ++i)
{
res.clear();
sum += bg_tree.query(bgi::intersects(search_box), std::back_inserter(res));
}
double s = t.elapsed();
std::cout << s << " Boost query " << sum << std::endl;
}
{
boost::timer t;
std::cout << "Tree contains " << bg_tree.size() << " box-id values." << std::endl;
while (!bg_tree.empty()) {
// 1. Choose arbitrary BoxIdPair to be the leader of a new canopy.
// Remove it from the tree. Insert it into the canopy map, with its
// corresponding id.
Rect const& r = rects[rects.size()-1];
point_t origin(r.min[0], r.min[0]);
rects.pop_back();
auto first = bgi::qbegin(bg_tree, bgi::nearest(origin, 1)),
last = bgi::qend(bg_tree);
if (first != last) {
bg_tree.remove(*first); // assuming single result
}
}
double s = t.elapsed();
std::cout << s << " Boost tree emptied " << std::endl;
}
}
Example output:
1.09421 Boost insert time
0.000371 Boost query 0
Tree contains 1000000 box-id values.
12.7237 Boost tree emptied
[1] Issue with removing points from a boost::geometry::index::rtree