osrm-backend/include/engine/routing_algorithms/many_to_many.hpp
2017-01-27 11:19:37 +01:00

139 lines
5.0 KiB
C++

#ifndef MANY_TO_MANY_ROUTING_HPP
#define MANY_TO_MANY_ROUTING_HPP
#include "engine/datafacade/datafacade_base.hpp"
#include "engine/routing_algorithms/routing_base.hpp"
#include "engine/search_engine_data.hpp"
#include "util/typedefs.hpp"
#include <boost/assert.hpp>
#include <limits>
#include <memory>
#include <unordered_map>
#include <vector>
namespace osrm
{
namespace engine
{
namespace routing_algorithms
{
class ManyToManyRouting final : public BasicRoutingInterface
{
using super = BasicRoutingInterface;
using QueryHeap = SearchEngineData::ManyToManyQueryHeap;
SearchEngineData &engine_working_data;
struct NodeBucket
{
unsigned target_id; // essentially a row in the weight matrix
EdgeWeight weight;
EdgeWeight duration;
NodeBucket(const unsigned target_id, const EdgeWeight weight, const EdgeWeight duration)
: target_id(target_id), weight(weight), duration(duration)
{
}
};
// FIXME This should be replaced by an std::unordered_multimap, though this needs benchmarking
using SearchSpaceWithBuckets = std::unordered_map<NodeID, std::vector<NodeBucket>>;
public:
ManyToManyRouting(SearchEngineData &engine_working_data)
: engine_working_data(engine_working_data)
{
}
std::vector<EdgeWeight>
operator()(const std::shared_ptr<const datafacade::BaseDataFacade> facade,
const std::vector<PhantomNode> &phantom_nodes,
const std::vector<std::size_t> &source_indices,
const std::vector<std::size_t> &target_indices) const;
void ForwardRoutingStep(const std::shared_ptr<const datafacade::BaseDataFacade> facade,
const unsigned row_idx,
const unsigned number_of_targets,
QueryHeap &query_heap,
const SearchSpaceWithBuckets &search_space_with_buckets,
std::vector<EdgeWeight> &weights_table,
std::vector<EdgeWeight> &durations_table) const;
void BackwardRoutingStep(const std::shared_ptr<const datafacade::BaseDataFacade> facade,
const unsigned column_idx,
QueryHeap &query_heap,
SearchSpaceWithBuckets &search_space_with_buckets) const;
template <bool forward_direction>
inline void RelaxOutgoingEdges(const std::shared_ptr<const datafacade::BaseDataFacade> facade,
const NodeID node,
const EdgeWeight weight,
const EdgeWeight duration,
QueryHeap &query_heap) const
{
for (auto edge : facade->GetAdjacentEdgeRange(node))
{
const auto &data = facade->GetEdgeData(edge);
const bool direction_flag = (forward_direction ? data.forward : data.backward);
if (direction_flag)
{
const NodeID to = facade->GetTarget(edge);
const EdgeWeight edge_weight = data.weight;
const EdgeWeight edge_duration = data.duration;
BOOST_ASSERT_MSG(edge_weight > 0, "edge_weight invalid");
const EdgeWeight to_weight = weight + edge_weight;
const EdgeWeight to_duration = duration + edge_duration;
// New Node discovered -> Add to Heap + Node Info Storage
if (!query_heap.WasInserted(to))
{
query_heap.Insert(to, to_weight, {node, to_duration});
}
// Found a shorter Path -> Update weight
else if (to_weight < query_heap.GetKey(to))
{
// new parent
query_heap.GetData(to) = {node, to_duration};
query_heap.DecreaseKey(to, to_weight);
}
}
}
}
// Stalling
template <bool forward_direction>
inline bool StallAtNode(const std::shared_ptr<const datafacade::BaseDataFacade> facade,
const NodeID node,
const EdgeWeight weight,
QueryHeap &query_heap) const
{
for (auto edge : facade->GetAdjacentEdgeRange(node))
{
const auto &data = facade->GetEdgeData(edge);
const bool reverse_flag = ((!forward_direction) ? data.forward : data.backward);
if (reverse_flag)
{
const NodeID to = facade->GetTarget(edge);
const EdgeWeight edge_weight = data.weight;
BOOST_ASSERT_MSG(edge_weight > 0, "edge_weight invalid");
if (query_heap.WasInserted(to))
{
if (query_heap.GetKey(to) + edge_weight < weight)
{
return true;
}
}
}
}
return false;
}
};
} // namespace routing_algorithms
} // namespace engine
} // namespace osrm
#endif