OSM Highway Lengths using libosmium

road_length.cpp

/*

  The code in this example file is released into the Public Domain.

  Simple output of road lengths (anything tagged highway=*) with optional print out of the split across highway types

  Easiest way to compile is to replace the file road_lengths.cpp in
      https://github.com/osmcode/osmium-contrib
   with this version, and the run make on the command line.
*/

#include <cstdlib>

#include <osmium/index/map/sparse_table.hpp>
#include <osmium/handler/node_locations_for_ways.hpp>
#include <osmium/io/any_input.hpp>
#include <osmium/visitor.hpp>
#include <osmium/osm/types.hpp>
#include <osmium/geom/haversine.hpp>

typedef osmium::index::map::SparseTable<osmium::unsigned_object_id_type, osmium::Location> index_type;
typedef osmium::handler::NodeLocationsForWays<index_type> location_handler_type;

class RoadLengthHandler : public osmium::handler::Handler {

	std::map<std::string, double> lengths;
	std::string hwy;
	bool verbose = false;

public:

	// Not using/don't need default destructor function
	RoadLengthHandler ( const bool vb )
	{
		verbose = vb;
	}

	void way(const osmium::Way& way) 
	{
		try {
			const char* highway = way.tags().get_value_by_key("highway");
			if (highway) {
				hwy.assign(highway);
				lengths[hwy] += osmium::geom::haversine::distance (way.nodes());
			}
		}
		catch (std::exception& e) {
			std::cerr << "Ignoring illegal geometry for way " << way.id() << ".\n";
		}
	}

	void done()
	{
		double total = 0.0;
		for (auto& l : lengths)
		{
			if (verbose)
				printf("%-20s%8.1f km\n", l.first.c_str(), l.second/1000.0 );
			total += l.second;
		}
		printf("TOTAL %8.1f km\n", total/1000.0);
	}
};

int main(int argc, char *argv[]) 
{
	if (argc != 2 && argc != 3 ) {
		std::cerr << "Usage: " << argv[0] << " OSMFILE"  << " [-v]"<< std::endl;
		exit(1);
	}

	try {
		osmium::osm_entity_bits::type read_types = osmium::osm_entity_bits::way | osmium::osm_entity_bits::node;
		osmium::io::File infile(argv[1]);
		osmium::io::Reader reader(infile, read_types);

		// By defualt processing ways only contains node references
		// Thus we have to create these tables of lookups to access positional node information of a way
		index_type index;
		location_handler_type location_handler(index);
		location_handler.ignore_errors();

		RoadLengthHandler handler ( argc == 3 );
		osmium::apply(reader, location_handler, handler );
		// 'done' no longer part of osmium::handler class so invoke manually
		handler.done();
	}
	catch (std::exception& e) {
		std::cerr << "Can not open file: " << argv[1] << std::endl;
		exit (2);
	}

	google::protobuf::ShutdownProtobufLibrary();

	return 0;
}