Cache the node priorities between runs

This speeds up processings on the same dataset significantly by creating
a .level file that saves the level in which a node was contracted.
It removes the need for expensive recomputation of priorities and such.

Use with care! Running `osrm-extract` again will invalidate .level
files.

contractor/contractor.hpp

@@ -158,6 +158,15 @@ class Contractor
 
   public:
     template <class ContainerT> Contractor(int nodes, ContainerT &input_edge_list)
+      : Contractor(nodes, input_edge_list, {}, {})
+    {
+    }
+
+    template <class ContainerT>
+    Contractor(int nodes,
+               ContainerT &input_edge_list,
+               std::vector<float> &&node_levels_)
+        : node_levels(std::move(node_levels_))
     {
         std::vector<ContractorEdge> edges;
         edges.reserve(input_edge_list.size() * 2);
@@ -305,14 +314,14 @@ class Contractor
         ThreadDataContainer thread_data_list(number_of_nodes);
 
         NodeID number_of_contracted_nodes = 0;
-        std::vector<RemainingNodeData> remaining_nodes(number_of_nodes);
+        std::vector<NodePriorityData> node_data;
-        std::vector<float> node_priorities(number_of_nodes);
+        std::vector<float> node_priorities;
-        std::vector<NodePriorityData> node_data(number_of_nodes);
         is_core_node.resize(number_of_nodes, false);
 
+        std::vector<RemainingNodeData> remaining_nodes(number_of_nodes);
         // initialize priorities in parallel
         tbb::parallel_for(tbb::blocked_range<int>(0, number_of_nodes, InitGrainSize),
-                          [&remaining_nodes](const tbb::blocked_range<int> &range)
+                          [this, &remaining_nodes](const tbb::blocked_range<int> &range)
                           {
                               for (int x = range.begin(), end = range.end(); x != end; ++x)
                               {
@@ -320,6 +329,19 @@ class Contractor
                               }
                           });
 
+        bool use_cached_node_priorities = !node_levels.empty();
+        if (use_cached_node_priorities)
+        {
+            std::cout << "using cached node priorities ..." << std::flush;
+            node_priorities.swap(node_levels);
+            std::cout << "ok" << std::endl;
+        }
+        else
+        {
+            node_data.resize(number_of_nodes);
+            node_priorities.resize(number_of_nodes);
+            node_levels.resize(number_of_nodes);
+
             std::cout << "initializing elimination PQ ..." << std::flush;
             tbb::parallel_for(tbb::blocked_range<int>(0, number_of_nodes, PQGrainSize),
                               [this, &node_priorities, &node_data, &thread_data_list](
@@ -332,9 +354,13 @@ class Contractor
                                           this->EvaluateNodePriority(data, &node_data[x], x);
                                   }
                               });
-        std::cout << "ok" << std::endl
+            std::cout << "ok" << std::endl;
-                  << "preprocessing " << number_of_nodes << " nodes ..." << std::flush;
+        }
+        BOOST_ASSERT(node_priorities.size() == number_of_nodes);
 
+        std::cout << "preprocessing " << number_of_nodes << " nodes ..." << std::flush;
+
+        unsigned current_level = 0;
         bool flushed_contractor = false;
         while (number_of_nodes > 2 &&
                number_of_contracted_nodes < static_cast<NodeID>(number_of_nodes * core_factor))
@@ -359,29 +385,32 @@ class Contractor
                 // remaining graph
                 std::vector<NodeID> new_node_id_from_orig_id_map(number_of_nodes, UINT_MAX);
 
-                // build forward and backward renumbering map and remap ids in remaining_nodes and
-                // Priorities.
                 for (const auto new_node_id : osrm::irange<std::size_t>(0, remaining_nodes.size()))
                 {
+                    auto& node = remaining_nodes[new_node_id];
+                    BOOST_ASSERT(node_priorities.size() > node.id);
+                    new_node_priority[new_node_id] = node_priorities[node.id];
+                }
+
+                // build forward and backward renumbering map and remap ids in remaining_nodes
+                for (const auto new_node_id : osrm::irange<std::size_t>(0, remaining_nodes.size()))
+                {
+                    auto& node = remaining_nodes[new_node_id];
                     // create renumbering maps in both directions
-                    orig_node_id_from_new_node_id_map[new_node_id] =
+                    orig_node_id_from_new_node_id_map[new_node_id] = node.id;
-                        remaining_nodes[new_node_id].id;
+                    new_node_id_from_orig_id_map[node.id] = new_node_id;
-                    new_node_id_from_orig_id_map[remaining_nodes[new_node_id].id] = new_node_id;
+                    node.id = new_node_id;
-                    new_node_priority[new_node_id] =
-                        node_priorities[remaining_nodes[new_node_id].id];
-                    remaining_nodes[new_node_id].id = new_node_id;
                 }
                 // walk over all nodes
-                for (const auto i :
+                for (const auto source :
-                     osrm::irange<std::size_t>(0, contractor_graph->GetNumberOfNodes()))
+                     osrm::irange<NodeID>(0, contractor_graph->GetNumberOfNodes()))
                 {
-                    const NodeID source = i;
                     for (auto current_edge : contractor_graph->GetAdjacentEdgeRange(source))
                     {
                         ContractorGraph::EdgeData &data =
                             contractor_graph->GetEdgeData(current_edge);
                         const NodeID target = contractor_graph->GetTarget(current_edge);
-                        if (SPECIAL_NODEID == new_node_id_from_orig_id_map[i])
+                        if (SPECIAL_NODEID == new_node_id_from_orig_id_map[source])
                         {
                             external_edge_list.push_back({source, target, data});
                         }
@@ -428,14 +457,13 @@ class Contractor
                 thread_data_list.number_of_nodes = contractor_graph->GetNumberOfNodes();
             }
 
-            const int last = (int)remaining_nodes.size();
+            tbb::parallel_for(tbb::blocked_range<std::size_t>(0, remaining_nodes.size(), IndependentGrainSize),
-            tbb::parallel_for(tbb::blocked_range<int>(0, last, IndependentGrainSize),
                               [this, &node_priorities, &remaining_nodes, &thread_data_list](
-                                  const tbb::blocked_range<int> &range)
+                                  const tbb::blocked_range<std::size_t> &range)
                               {
                                   ContractorThreadData *data = thread_data_list.getThreadData();
                                   // determine independent node set
-                                  for (int i = range.begin(), end = range.end(); i != end; ++i)
+                                  for (auto i = range.begin(), end = range.end(); i != end; ++i)
                                   {
                                       const NodeID node = remaining_nodes[i].id;
                                       remaining_nodes[i].is_independent =
@@ -443,17 +471,45 @@ class Contractor
                                   }
                               });
 
-            const auto first = stable_partition(remaining_nodes.begin(), remaining_nodes.end(),
+            // sort all remaining nodes to the beginning of the sequence
+            const auto begin_independent_nodes = stable_partition(remaining_nodes.begin(), remaining_nodes.end(),
                                                 [](RemainingNodeData node_data)
                                                 {
                                                     return !node_data.is_independent;
                                                 });
-            const int first_independent_node = static_cast<int>(first - remaining_nodes.begin());
+            auto begin_independent_nodes_idx = std::distance(remaining_nodes.begin(), begin_independent_nodes);
+            auto end_independent_nodes_idx = remaining_nodes.size();
+
+            if (!use_cached_node_priorities)
+            {
+                // write out contraction level
+                tbb::parallel_for(
+                    tbb::blocked_range<std::size_t>(begin_independent_nodes_idx, end_independent_nodes_idx, ContractGrainSize),
+                    [this, remaining_nodes, flushed_contractor, current_level](const tbb::blocked_range<std::size_t> &range)
+                    {
+                        if (flushed_contractor)
+                        {
+                            for (int position = range.begin(), end = range.end(); position != end; ++position)
+                            {
+                                const NodeID x = remaining_nodes[position].id;
+                                node_levels[orig_node_id_from_new_node_id_map[x]] = current_level;
+                            }
+                        }
+                        else
+                        {
+                            for (int position = range.begin(), end = range.end(); position != end; ++position)
+                            {
+                                const NodeID x = remaining_nodes[position].id;
+                                node_levels[x] = current_level;
+                            }
+                        }
+                    });
+            }
 
             // contract independent nodes
             tbb::parallel_for(
-                tbb::blocked_range<int>(first_independent_node, last, ContractGrainSize),
+                tbb::blocked_range<std::size_t>(begin_independent_nodes_idx, end_independent_nodes_idx, ContractGrainSize),
-                [this, &remaining_nodes, &thread_data_list](const tbb::blocked_range<int> &range)
+                [this, &remaining_nodes, &thread_data_list](const tbb::blocked_range<std::size_t> &range)
                 {
                     ContractorThreadData *data = thread_data_list.getThreadData();
                     for (int position = range.begin(), end = range.end(); position != end; ++position)
@@ -462,17 +518,9 @@ class Contractor
                         this->ContractNode<false>(data, x);
                     }
                 });
-            // make sure we really sort each block
+
             tbb::parallel_for(
-                thread_data_list.data.range(),
+                tbb::blocked_range<int>(begin_independent_nodes_idx, end_independent_nodes_idx, DeleteGrainSize),
-                [&](const ThreadDataContainer::EnumerableThreadData::range_type &range)
-                {
-                    for (auto &data : range)
-                        tbb::parallel_sort(data->inserted_edges.begin(),
-                                           data->inserted_edges.end());
-                });
-            tbb::parallel_for(
-                tbb::blocked_range<int>(first_independent_node, last, DeleteGrainSize),
                 [this, &remaining_nodes, &thread_data_list](const tbb::blocked_range<int> &range)
                 {
                     ContractorThreadData *data = thread_data_list.getThreadData();
@@ -483,6 +531,16 @@ class Contractor
                     }
                 });
 
+            // make sure we really sort each block
+            tbb::parallel_for(
+                thread_data_list.data.range(),
+                [&](const ThreadDataContainer::EnumerableThreadData::range_type &range)
+                {
+                    for (auto &data : range)
+                        tbb::parallel_sort(data->inserted_edges.begin(),
+                                           data->inserted_edges.end());
+                });
+
             // insert new edges
             for (auto &data : thread_data_list.data)
             {
@@ -508,9 +566,11 @@ class Contractor
                 data->inserted_edges.clear();
             }
 
+            if (!use_cached_node_priorities)
+            {
                 tbb::parallel_for(
-                tbb::blocked_range<int>(first_independent_node, last, NeighboursGrainSize),
+                    tbb::blocked_range<int>(begin_independent_nodes_idx, end_independent_nodes_idx, NeighboursGrainSize),
-                [this, &remaining_nodes, &node_priorities, &node_data, &thread_data_list](
+                    [this, &node_priorities, &remaining_nodes, &node_data, &thread_data_list](
                         const tbb::blocked_range<int> &range)
                     {
                         ContractorThreadData *data = thread_data_list.getThreadData();
@@ -520,11 +580,11 @@ class Contractor
                             this->UpdateNodeNeighbours(node_priorities, node_data, data, x);
                         }
                     });
+            }
 
             // remove contracted nodes from the pool
-            number_of_contracted_nodes += last - first_independent_node;
+            number_of_contracted_nodes += end_independent_nodes_idx - begin_independent_nodes_idx;
-            remaining_nodes.resize(first_independent_node);
+            remaining_nodes.resize(begin_independent_nodes_idx);
-            remaining_nodes.shrink_to_fit();
             //            unsigned maxdegree = 0;
             //            unsigned avgdegree = 0;
             //            unsigned mindegree = UINT_MAX;
@@ -551,24 +611,36 @@ class Contractor
             //            quad: " << quaddegree;
 
             p.printStatus(number_of_contracted_nodes);
+            ++current_level;
         }
 
         if (remaining_nodes.size() > 2)
         {
-            if (orig_node_id_from_new_node_id_map.empty())
+              if (orig_node_id_from_new_node_id_map.size() > 0)
               {
-                for (const auto &node : remaining_nodes)
+                  tbb::parallel_for(
+                      tbb::blocked_range<int>(0, remaining_nodes.size(), InitGrainSize),
+                      [this, &remaining_nodes](const tbb::blocked_range<int> &range)
                       {
-                    is_core_node[node.id] = true;
+                          for (int x = range.begin(), end = range.end(); x != end; ++x)
+                          {
+                              const auto orig_id = remaining_nodes[x].id;
+                              is_core_node[orig_node_id_from_new_node_id_map[orig_id]] = true;
                           }
+                      });
               }
               else
               {
-              for (const auto &node : remaining_nodes)
+                  tbb::parallel_for(
+                      tbb::blocked_range<int>(0, remaining_nodes.size(), InitGrainSize),
+                      [this, &remaining_nodes](const tbb::blocked_range<int> &range)
                       {
-                  auto orig_id = orig_node_id_from_new_node_id_map[node.id];
+                          for (int x = range.begin(), end = range.end(); x != end; ++x)
+                          {
+                              const auto orig_id = remaining_nodes[x].id;
                               is_core_node[orig_id] = true;
                           }
+                      });
               }
         }
         else
@@ -589,6 +661,11 @@ class Contractor
         out_is_core_node.swap(is_core_node);
     }
 
+    inline void GetNodeLevels(std::vector<float> &out_node_levels)
+    {
+        out_node_levels.swap(node_levels);
+    }
+
     template <class Edge> inline void GetEdges(DeallocatingVector<Edge> &edges)
     {
         Percent p(contractor_graph->GetNumberOfNodes());
@@ -998,6 +1075,7 @@ class Contractor
     std::shared_ptr<ContractorGraph> contractor_graph;
     stxxl::vector<QueryEdge> external_edge_list;
     std::vector<NodeID> orig_node_id_from_new_node_id_map;
+    std::vector<float> node_levels;
     std::vector<bool> is_core_node;
     XORFastHash fast_hash;
 };

contractor/contractor_options.cpp

@@ -48,16 +48,20 @@ ContractorOptions::ParseArguments(int argc, char *argv[], ContractorConfig &cont
     // declare a group of options that will be allowed both on command line and in config file
     boost::program_options::options_description config_options("Configuration");
     config_options.add_options()(
-        "profile,p", boost::program_options::value<boost::filesystem::path>(&contractor_config.profile_path)
+        "profile,p",
+        boost::program_options::value<boost::filesystem::path>(&contractor_config.profile_path)
             ->default_value("profile.lua"),
         "Path to LUA routing profile")(
-        "threads,t", boost::program_options::value<unsigned int>(&contractor_config.requested_num_threads)
+        "threads,t",
+        boost::program_options::value<unsigned int>(&contractor_config.requested_num_threads)
             ->default_value(tbb::task_scheduler_init::default_num_threads()),
         "Number of threads to use")(
-		"core,k", boost::program_options::value<double>(&contractor_config.core_factor)
+        "core,k",
-						 ->default_value(1.0),"Percentage of the graph (in vertices) to contract [0.1]");
+        boost::program_options::value<double>(&contractor_config.core_factor)->default_value(1.0),
-
+        "Percentage of the graph (in vertices) to contract [0.1]")(
-
+        "level-cache,o",
+        boost::program_options::value<bool>(&contractor_config.use_cached_priority)->default_value(false),
+        "Use .level file to retain the contaction level for each node from the last run.");
 
     // hidden options, will be allowed both on command line and in config file, but will not be
     // shown to the user
@@ -122,6 +126,7 @@ ContractorOptions::ParseArguments(int argc, char *argv[], ContractorConfig &cont
 
 void ContractorOptions::GenerateOutputFilesNames(ContractorConfig &contractor_config)
 {
+    contractor_config.level_output_path = contractor_config.osrm_input_path.string() + ".level";
     contractor_config.core_output_path = contractor_config.osrm_input_path.string() + ".core";
     contractor_config.graph_output_path = contractor_config.osrm_input_path.string() + ".hsgr";
     contractor_config.edge_based_graph_path = contractor_config.osrm_input_path.string() + ".ebg";

contractor/contractor_options.hpp

@@ -47,10 +47,13 @@ struct ContractorConfig
     boost::filesystem::path osrm_input_path;
     boost::filesystem::path profile_path;
 
+    std::string level_output_path;
     std::string core_output_path;
     std::string graph_output_path;
     std::string edge_based_graph_path;
 
+    bool use_cached_priority;
+
     unsigned requested_num_threads;
 
     //A percentage of vertices that will be contracted for the hierarchy.

contractor/processing_chain.cpp

@@ -26,8 +26,8 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
 #include "processing_chain.hpp"
-
 #include "contractor.hpp"
+
 #include "../data_structures/deallocating_vector.hpp"
 
 #include "../algorithms/crc32_processor.hpp"
@@ -78,8 +78,13 @@ int Prepare::Run()
 
     TIMER_START(contraction);
     std::vector<bool> is_core_node;
+    std::vector<float> node_levels;
+    if (config.use_cached_priority)
+    {
+        ReadNodeLevels(node_levels);
+    }
     DeallocatingVector<QueryEdge> contracted_edge_list;
-    ContractGraph(max_edge_id, edge_based_edge_list, contracted_edge_list, is_core_node);
+    ContractGraph(max_edge_id, edge_based_edge_list, contracted_edge_list, is_core_node, node_levels);
     TIMER_STOP(contraction);
 
     SimpleLogger().Write() << "Contraction took " << TIMER_SEC(contraction) << " sec";
@@ -87,6 +92,10 @@ int Prepare::Run()
     std::size_t number_of_used_edges =
         WriteContractedGraph(max_edge_id, contracted_edge_list);
     WriteCoreNodeMarker(std::move(is_core_node));
+    if (!config.use_cached_priority)
+    {
+        WriteNodeLevels(std::move(node_levels));
+    }
 
     TIMER_STOP(preparing);
 
@@ -131,11 +140,35 @@ std::size_t Prepare::LoadEdgeExpandedGraph(
     return max_edge_id;
 }
 
+void Prepare::ReadNodeLevels(std::vector<float> &node_levels) const
+{
+    boost::filesystem::ifstream order_input_stream(config.level_output_path,
+                                                          std::ios::binary);
+
+    unsigned level_size;
+    order_input_stream.read((char *)&level_size, sizeof(unsigned));
+    node_levels.resize(level_size);
+    order_input_stream.read((char *)node_levels.data(),
+                                    sizeof(float) * node_levels.size());
+}
+
+void Prepare::WriteNodeLevels(std::vector<float> &&in_node_levels) const
+{
+    std::vector<float> node_levels(std::move(in_node_levels));
+
+    boost::filesystem::ofstream order_output_stream(config.level_output_path,
+                                                          std::ios::binary);
+
+    unsigned level_size = node_levels.size();
+    order_output_stream.write((char *)&level_size, sizeof(unsigned));
+    order_output_stream.write((char *)node_levels.data(),
+                                    sizeof(float) * node_levels.size());
+}
 
 void Prepare::WriteCoreNodeMarker(std::vector<bool> &&in_is_core_node) const
 {
-    std::vector<bool> is_core_node(in_is_core_node);
+    std::vector<bool> is_core_node(std::move(in_is_core_node));
-    std::vector<char> unpacked_bool_flags(is_core_node.size());
+    std::vector<char> unpacked_bool_flags(std::move(is_core_node.size()));
     for (auto i = 0u; i < is_core_node.size(); ++i)
     {
         unpacked_bool_flags[i] = is_core_node[i] ? 1 : 0;
@@ -270,12 +303,17 @@ std::size_t Prepare::WriteContractedGraph(unsigned max_node_id,
 void Prepare::ContractGraph(const unsigned max_edge_id,
                             DeallocatingVector<EdgeBasedEdge> &edge_based_edge_list,
                             DeallocatingVector<QueryEdge> &contracted_edge_list,
-                            std::vector<bool> &is_core_node)
+                            std::vector<bool> &is_core_node,
+                            std::vector<float> &inout_node_levels) const
 {
-    Contractor contractor(max_edge_id + 1, edge_based_edge_list);
+    std::vector<float> node_levels;
+    node_levels.swap(inout_node_levels);
+
+    Contractor contractor(max_edge_id + 1, edge_based_edge_list, std::move(node_levels));
     contractor.Run(config.core_factor);
     contractor.GetEdges(contracted_edge_list);
     contractor.GetCoreMarker(is_core_node);
+    contractor.GetNodeLevels(inout_node_levels);
 }
 
 

contractor/processing_chain.hpp

@@ -60,8 +60,11 @@ class Prepare
     void ContractGraph(const unsigned max_edge_id,
                        DeallocatingVector<EdgeBasedEdge> &edge_based_edge_list,
                        DeallocatingVector<QueryEdge> &contracted_edge_list,
-                       std::vector<bool> &is_core_node);
+                       std::vector<bool> &is_core_node,
+                       std::vector<float> &node_levels) const;
     void WriteCoreNodeMarker(std::vector<bool> &&is_core_node) const;
+    void WriteNodeLevels(std::vector<float> &&node_levels) const;
+    void ReadNodeLevels(std::vector<float> &contraction_order) const;
     std::size_t WriteContractedGraph(unsigned number_of_edge_based_nodes,
                                      const DeallocatingVector<QueryEdge> &contracted_edge_list);
     void FindComponents(unsigned max_edge_id,