osrm-backend/include/customizer/cell_customizer.hpp
2017-03-08 16:08:00 +00:00

149 lines
5.0 KiB
C++

#ifndef OSRM_CELLS_CUSTOMIZER_HPP
#define OSRM_CELLS_CUSTOMIZER_HPP
#include "partition/cell_storage.hpp"
#include "partition/multi_level_partition.hpp"
#include "util/binary_heap.hpp"
#include <boost/thread/tss.hpp>
#include <unordered_set>
namespace osrm
{
namespace customize
{
class CellCustomizer
{
public:
CellCustomizer(const partition::MultiLevelPartition &partition) : partition(partition) {}
template <typename GraphT>
void Customize(const GraphT &graph,
partition::CellStorage &cells,
partition::LevelID level,
partition::CellID id)
{
auto cell = cells.GetCell(level, id);
auto destinations = cell.GetDestinationNodes();
// for each source do forward search
for (auto source : cell.GetSourceNodes())
{
std::unordered_set<NodeID> destinations_set(destinations.begin(), destinations.end());
Heap heap(graph.GetNumberOfNodes());
heap.Insert(source, 0, {});
// explore search space
while (!heap.Empty() && !destinations_set.empty())
{
const NodeID node = heap.DeleteMin();
const EdgeWeight weight = heap.GetKey(node);
if (level == 1)
RelaxNode<true>(graph, cells, heap, level, id, node, weight);
else
RelaxNode<false>(graph, cells, heap, level, id, node, weight);
destinations_set.erase(node);
}
// fill a map of destination nodes to placeholder pointers
auto destination_iter = destinations.begin();
for (auto &weight : cell.GetOutWeight(source))
{
BOOST_ASSERT(destination_iter != destinations.end());
const auto destination = *destination_iter++;
weight =
heap.WasInserted(destination) ? heap.GetKey(destination) : INVALID_EDGE_WEIGHT;
}
}
}
template <typename GraphT> void Customize(const GraphT &graph, partition::CellStorage &cells)
{
for (std::size_t level = 1; level < partition.GetNumberOfLevels(); ++level)
{
tbb::parallel_for(tbb::blocked_range<std::size_t>(0, partition.GetNumberOfCells(level)),
[&](const tbb::blocked_range<std::size_t> &range) {
for (auto id = range.begin(), end = range.end(); id != end; ++id)
{
Customize(graph, cells, level, id);
}
});
}
}
private:
struct HeapData
{
};
using Heap = util::
BinaryHeap<NodeID, NodeID, EdgeWeight, HeapData, util::UnorderedMapStorage<NodeID, int>>;
using HeapPtr = boost::thread_specific_ptr<Heap>;
template <bool first_level, typename GraphT>
void RelaxNode(const GraphT &graph,
const partition::CellStorage &cells,
Heap &heap,
partition::LevelID level,
partition::CellID id,
NodeID node,
EdgeWeight weight) const
{
if (!first_level)
{
// Relax sub-cell nodes
auto subcell_id = partition.GetCell(level - 1, node);
auto subcell = cells.GetCell(level - 1, subcell_id);
auto subcell_destination = subcell.GetDestinationNodes().begin();
for (auto subcell_weight : subcell.GetOutWeight(node))
{
if (subcell_weight != INVALID_EDGE_WEIGHT)
{
const NodeID to = *subcell_destination;
const EdgeWeight to_weight = subcell_weight + weight;
if (!heap.WasInserted(to))
{
heap.Insert(to, to_weight, {});
}
else if (to_weight < heap.GetKey(to))
{
heap.DecreaseKey(to, to_weight);
}
}
++subcell_destination;
}
}
// Relax base graph edges if a sub-cell border edge
for (auto edge : graph.GetAdjacentEdgeRange(node))
{
const NodeID to = graph.GetTarget(edge);
const auto &data = graph.GetEdgeData(edge);
if (data.forward && partition.GetCell(level, to) == id &&
(first_level ||
partition.GetCell(level - 1, node) != partition.GetCell(level - 1, to)))
{
const EdgeWeight to_weight = data.weight + weight;
if (!heap.WasInserted(to))
{
heap.Insert(to, to_weight, {});
}
else if (to_weight < heap.GetKey(to))
{
heap.DecreaseKey(to, to_weight);
}
}
}
}
const partition::MultiLevelPartition &partition;
};
}
}
#endif // OSRM_CELLS_CUSTOMIZER_HPP