osrm-backend/include/contractor/contract_excludable_graph.hpp
2024-05-06 09:14:46 +02:00

100 lines
3.9 KiB
C++

#ifndef OSRM_CONTRACTOR_CONTRACT_EXCLUDABLE_GRAPH_HPP
#define OSRM_CONTRACTOR_CONTRACT_EXCLUDABLE_GRAPH_HPP
#include "contractor/contracted_edge_container.hpp"
#include "contractor/contractor_graph.hpp"
#include "contractor/graph_contractor.hpp"
#include "contractor/graph_contractor_adaptors.hpp"
#include "contractor/query_graph.hpp"
namespace osrm::contractor
{
using GraphAndFilter = std::tuple<QueryGraph, std::vector<std::vector<bool>>>;
inline auto contractFullGraph(ContractorGraph contractor_graph,
std::vector<EdgeWeight> node_weights)
{
auto num_nodes = contractor_graph.GetNumberOfNodes();
contractGraph(contractor_graph, std::move(node_weights));
auto edges = toEdges<QueryEdge>(std::move(contractor_graph));
std::vector<bool> edge_filter(edges.size(), true);
return GraphAndFilter{QueryGraph{num_nodes, edges}, {std::move(edge_filter)}};
}
inline auto contractExcludableGraph(ContractorGraph contractor_graph_,
std::vector<EdgeWeight> node_weights,
const std::vector<std::vector<bool>> &filters)
{
if (filters.size() == 1)
{
if (std::all_of(filters.front().begin(), filters.front().end(), [](auto v) { return v; }))
{
return contractFullGraph(std::move(contractor_graph_), std::move(node_weights));
}
}
auto num_nodes = contractor_graph_.GetNumberOfNodes();
ContractedEdgeContainer edge_container;
ContractorGraph shared_core_graph;
std::vector<bool> is_shared_core;
{
ContractorGraph contractor_graph = std::move(contractor_graph_);
std::vector<bool> always_allowed(num_nodes, true);
for (const auto &filter : filters)
{
for (const auto node : util::irange<NodeID>(0, num_nodes))
{
always_allowed[node] = always_allowed[node] && filter[node];
}
}
// By not contracting all contractable nodes we avoid creating
// a very dense core. This increases the overall graph sizes a little bit
// but increases the final CH quality and contraction speed.
constexpr float BASE_CORE = 0.9f;
is_shared_core =
contractGraph(contractor_graph, std::move(always_allowed), node_weights, BASE_CORE);
// Add all non-core edges to container
{
auto non_core_edges = toEdges<QueryEdge>(contractor_graph);
auto new_end = std::remove_if(non_core_edges.begin(),
non_core_edges.end(),
[&](const auto &edge) {
return is_shared_core[edge.source] &&
is_shared_core[edge.target];
});
non_core_edges.resize(new_end - non_core_edges.begin());
edge_container.Insert(std::move(non_core_edges));
for (const auto filter_index : util::irange<std::size_t>(0, filters.size()))
{
edge_container.Filter(filters[filter_index], filter_index);
}
}
// Extract core graph for further contraction
shared_core_graph = contractor_graph.Filter([&is_shared_core](const NodeID node)
{ return is_shared_core[node]; });
}
for (const auto &filter : filters)
{
auto filtered_core_graph =
shared_core_graph.Filter([&filter](const NodeID node) { return filter[node]; });
contractGraph(filtered_core_graph, is_shared_core, is_shared_core, node_weights);
edge_container.Merge(toEdges<QueryEdge>(std::move(filtered_core_graph)));
}
return GraphAndFilter{QueryGraph{num_nodes, edge_container.edges},
edge_container.MakeEdgeFilters()};
}
} // namespace osrm::contractor
#endif