Add support for multiple via-way restrictions (#5907)

Currently OSRM only supports turn restrictions with a single via-node or one
via-way. OSM allows for multiple via-ways to represent longer and more
complex restrictions.

This PR extends the use of duplicate nodes for representng via-way turn
restrictions to also support multi via-way restrictions. Effectively, this
increases the edge-based graph size by the number of edges in multi via-way
restrictions. However, given the low number of these restrictions it
has little effect on total graph size.

In addition, we add a new step in the extraction phase that constructs
a restriction graph to support more complex relationships between restrictions,
such as nested restrictions and overlapping restrictions.

include/extractor/edge_based_graph_factory.hpp

@@ -12,8 +12,8 @@
 #include "extractor/name_table.hpp"
 #include "extractor/nbg_to_ebg.hpp"
 #include "extractor/node_data_container.hpp"
+#include "extractor/node_restriction_map.hpp"
 #include "extractor/query_node.hpp"
-#include "extractor/restriction_index.hpp"
 #include "extractor/turn_lane_types.hpp"
 #include "extractor/way_restriction_map.hpp"
 

include/extractor/extraction_containers.hpp

@@ -1,14 +1,16 @@
 #ifndef EXTRACTION_CONTAINERS_HPP
 #define EXTRACTION_CONTAINERS_HPP
 
-#include "extractor/first_and_last_segment_of_way.hpp"
 #include "extractor/internal_extractor_edge.hpp"
+#include "extractor/nodes_of_way.hpp"
 #include "extractor/query_node.hpp"
 #include "extractor/restriction.hpp"
 #include "extractor/scripting_environment.hpp"
 
 #include "storage/tar_fwd.hpp"
 
+#include <unordered_map>
+
 namespace osrm
 {
 namespace extractor
@@ -22,9 +24,16 @@ namespace extractor
  */
 class ExtractionContainers
 {
+    using ReferencedWays = std::unordered_map<OSMWayID, NodesOfWay>;
+    // The relationship between way and nodes is lost during node preparation.
+    // We identify the ways and nodes relevant to restrictions/overrides prior to
+    // node processing so that they can be referenced in the preparation phase.
+    ReferencedWays IdentifyRestrictionWays();
+    ReferencedWays IdentifyManeuverOverrideWays();
+
     void PrepareNodes();
-    void PrepareManeuverOverrides();
-    void PrepareRestrictions();
+    void PrepareManeuverOverrides(const ReferencedWays &maneuver_override_ways);
+    void PrepareRestrictions(const ReferencedWays &restriction_ways);
     void PrepareEdges(ScriptingEnvironment &scripting_environment);
 
     void WriteNodes(storage::tar::FileWriter &file_out) const;
@@ -37,9 +46,10 @@ class ExtractionContainers
     using NodeVector = std::vector<QueryNode>;
     using EdgeVector = std::vector<InternalExtractorEdge>;
     using AnnotationDataVector = std::vector<NodeBasedEdgeAnnotation>;
-    using WayIDStartEndVector = std::vector<FirstAndLastSegmentOfWay>;
     using NameCharData = std::vector<unsigned char>;
-    using NameOffsets = std::vector<unsigned>;
+    using NameOffsets = std::vector<size_t>;
+    using WayIDVector = std::vector<OSMWayID>;
+    using WayNodeIDOffsets = std::vector<size_t>;
 
     std::vector<OSMNodeID> barrier_nodes;
     std::vector<OSMNodeID> traffic_signals;
@@ -49,20 +59,18 @@ class ExtractionContainers
     AnnotationDataVector all_edges_annotation_data_list;
     NameCharData name_char_data;
     NameOffsets name_offsets;
-    // an adjacency array containing all turn lane masks
-    WayIDStartEndVector way_start_end_id_list;
+    WayIDVector ways_list;
+    // Offsets into used nodes for each way_list entry
+    WayNodeIDOffsets way_node_id_offsets;
 
     unsigned max_internal_node_id;
 
-    // list of restrictions before we transform them into the output types. Input containers
-    // reference OSMNodeIDs. We can only transform them to the correct internal IDs after we've read
-    // everything. Without a multi-parse approach, we have to remember the output restrictions
-    // before converting them to the internal formats
-    std::vector<InputConditionalTurnRestriction> restrictions_list;
-
-    // turn restrictions split into conditional and unconditional turn restrictions
-    std::vector<ConditionalTurnRestriction> conditional_turn_restrictions;
-    std::vector<TurnRestriction> unconditional_turn_restrictions;
+    // List of restrictions (conditional and unconditional) before we transform them into the
+    // output types. Input containers reference OSMNodeIDs. We can only transform them to the
+    // correct internal IDs after we've read everything. Without a multi-parse approach,
+    // we have to remember the output restrictions before converting them to the internal formats
+    std::vector<InputTurnRestriction> restrictions_list;
+    std::vector<TurnRestriction> turn_restrictions;
 
     std::vector<InputManeuverOverride> external_maneuver_overrides_list;
     std::vector<UnresolvedManeuverOverride> internal_maneuver_overrides;

include/extractor/extractor.hpp

@@ -42,6 +42,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "util/guidance/entry_class.hpp"
 #include "util/guidance/turn_lanes.hpp"
 
+#include "restriction_graph.hpp"
 #include "util/typedefs.hpp"
 
 namespace osrm
@@ -63,7 +64,6 @@ class Extractor
 
     std::tuple<LaneDescriptionMap,
                std::vector<TurnRestriction>,
-               std::vector<ConditionalTurnRestriction>,
                std::vector<UnresolvedManeuverOverride>>
     ParseOSMData(ScriptingEnvironment &scripting_environment, const unsigned number_of_threads);
 
@@ -74,8 +74,7 @@ class Extractor
         const CompressedEdgeContainer &compressed_edge_container,
         const std::unordered_set<NodeID> &barrier_nodes,
         const std::unordered_set<NodeID> &traffic_lights,
-        const std::vector<TurnRestriction> &turn_restrictions,
-        const std::vector<ConditionalTurnRestriction> &conditional_turn_restrictions,
+        const RestrictionGraph &restriction_graph,
         const std::unordered_set<EdgeID> &segregated_edges,
         const NameTable &name_table,
         const std::vector<UnresolvedManeuverOverride> &maneuver_overrides,
@@ -97,23 +96,16 @@ class Extractor
                         EdgeBasedNodeDataContainer &nodes_container) const;
     void BuildRTree(std::vector<EdgeBasedNodeSegment> edge_based_node_segments,
                     const std::vector<util::Coordinate> &coordinates);
-    std::shared_ptr<RestrictionMap> LoadRestrictionMap();
 
-    void WriteConditionalRestrictions(
-        const std::string &path,
-        std::vector<ConditionalTurnRestriction> &conditional_turn_restrictions);
-
-    void ProcessGuidanceTurns(
-        const util::NodeBasedDynamicGraph &node_based_graph,
-        const EdgeBasedNodeDataContainer &edge_based_node_container,
-        const std::vector<util::Coordinate> &node_coordinates,
-        const CompressedEdgeContainer &compressed_edge_container,
-        const std::unordered_set<NodeID> &barrier_nodes,
-        const std::vector<TurnRestriction> &turn_restrictions,
-        const std::vector<ConditionalTurnRestriction> &conditional_turn_restrictions,
-        const NameTable &name_table,
-        LaneDescriptionMap lane_description_map,
-        ScriptingEnvironment &scripting_environment);
+    void ProcessGuidanceTurns(const util::NodeBasedDynamicGraph &node_based_graph,
+                              const EdgeBasedNodeDataContainer &edge_based_node_container,
+                              const std::vector<util::Coordinate> &node_coordinates,
+                              const CompressedEdgeContainer &compressed_edge_container,
+                              const std::unordered_set<NodeID> &barrier_nodes,
+                              const RestrictionGraph &restriction_graph,
+                              const NameTable &name_table,
+                              LaneDescriptionMap lane_description_map,
+                              ScriptingEnvironment &scripting_environment);
 };
 } // namespace extractor
 } // namespace osrm

include/extractor/extractor_callbacks.hpp

@@ -47,7 +47,7 @@ struct ExtractionNode;
 struct ExtractionWay;
 struct ExtractionRelation;
 struct ProfileProperties;
-struct InputConditionalTurnRestriction;
+struct InputTurnRestriction;
 struct InputManeuverOverride;
 
 /**
@@ -87,7 +87,7 @@ class ExtractorCallbacks
     void ProcessNode(const osmium::Node &current_node, const ExtractionNode &result_node);
 
     // warning: caller needs to take care of synchronization!
-    void ProcessRestriction(const InputConditionalTurnRestriction &restriction);
+    void ProcessRestriction(const InputTurnRestriction &restriction);
 
     // warning: caller needs to take care of synchronization!
     void ProcessWay(const osmium::Way &current_way, const ExtractionWay &result_way);

include/extractor/first_and_last_segment_of_way.hpp

@@ -1,59 +0,0 @@
-#ifndef FIRST_AND_LAST_SEGMENT_OF_WAY_HPP
-#define FIRST_AND_LAST_SEGMENT_OF_WAY_HPP
-
-#include "util/typedefs.hpp"
-
-#include <limits>
-#include <string>
-
-namespace osrm
-{
-namespace extractor
-{
-
-struct FirstAndLastSegmentOfWay
-{
-    OSMWayID way_id;
-    OSMNodeID first_segment_source_id;
-    OSMNodeID first_segment_target_id;
-    OSMNodeID last_segment_source_id;
-    OSMNodeID last_segment_target_id;
-
-    FirstAndLastSegmentOfWay()
-        : way_id(SPECIAL_OSM_WAYID), first_segment_source_id(SPECIAL_OSM_NODEID),
-          first_segment_target_id(SPECIAL_OSM_NODEID), last_segment_source_id(SPECIAL_OSM_NODEID),
-          last_segment_target_id(SPECIAL_OSM_NODEID)
-    {
-    }
-
-    FirstAndLastSegmentOfWay(OSMWayID w, OSMNodeID fs, OSMNodeID ft, OSMNodeID ls, OSMNodeID lt)
-        : way_id(std::move(w)), first_segment_source_id(std::move(fs)),
-          first_segment_target_id(std::move(ft)), last_segment_source_id(std::move(ls)),
-          last_segment_target_id(std::move(lt))
-    {
-    }
-
-    static FirstAndLastSegmentOfWay min_value()
-    {
-        return {MIN_OSM_WAYID, MIN_OSM_NODEID, MIN_OSM_NODEID, MIN_OSM_NODEID, MIN_OSM_NODEID};
-    }
-    static FirstAndLastSegmentOfWay max_value()
-    {
-        return {MAX_OSM_WAYID, MAX_OSM_NODEID, MAX_OSM_NODEID, MAX_OSM_NODEID, MAX_OSM_NODEID};
-    }
-};
-
-struct FirstAndLastSegmentOfWayCompare
-{
-    using value_type = FirstAndLastSegmentOfWay;
-    bool operator()(const FirstAndLastSegmentOfWay &a, const FirstAndLastSegmentOfWay &b) const
-    {
-        return a.way_id < b.way_id;
-    }
-    value_type max_value() { return FirstAndLastSegmentOfWay::max_value(); }
-    value_type min_value() { return FirstAndLastSegmentOfWay::min_value(); }
-};
-} // namespace extractor
-} // namespace osrm
-
-#endif /* FIRST_AND_LAST_SEGMENT_OF_WAY_HPP */

include/extractor/graph_compressor.hpp

@@ -28,7 +28,6 @@ class GraphCompressor
                   const std::unordered_set<NodeID> &traffic_lights,
                   ScriptingEnvironment &scripting_environment,
                   std::vector<TurnRestriction> &turn_restrictions,
-                  std::vector<ConditionalTurnRestriction> &conditional_turn_restrictions,
                   std::vector<UnresolvedManeuverOverride> &maneuver_overrides,
                   util::NodeBasedDynamicGraph &graph,
                   const std::vector<NodeBasedEdgeAnnotation> &node_data_container,

include/extractor/intersection/intersection_analysis.hpp

@@ -5,7 +5,7 @@
 #include "extractor/intersection/intersection_edge.hpp"
 #include "extractor/intersection/intersection_view.hpp"
 #include "extractor/intersection/mergable_road_detector.hpp"
-#include "extractor/restriction_index.hpp"
+#include "extractor/node_restriction_map.hpp"
 #include "extractor/turn_lane_types.hpp"
 
 #include "util/coordinate.hpp"

include/extractor/intersection/mergable_road_detector.hpp

@@ -5,7 +5,7 @@
 #include "extractor/intersection/coordinate_extractor.hpp"
 #include "extractor/intersection/have_identical_names.hpp"
 #include "extractor/name_table.hpp"
-#include "extractor/restriction_index.hpp"
+#include "extractor/node_restriction_map.hpp"
 #include "extractor/turn_lane_types.hpp"
 
 #include "guidance/intersection.hpp"

include/extractor/node_based_graph_factory.hpp

@@ -40,7 +40,6 @@ class NodeBasedGraphFactory
     NodeBasedGraphFactory(const boost::filesystem::path &input_file,
                           ScriptingEnvironment &scripting_environment,
                           std::vector<TurnRestriction> &turn_restrictions,
-                          std::vector<ConditionalTurnRestriction> &conditional_turn_restrictions,
                           std::vector<UnresolvedManeuverOverride> &maneuver_overrides);
 
     auto const &GetGraph() const { return compressed_output_graph; }
@@ -69,7 +68,6 @@ class NodeBasedGraphFactory
     // edges into a single representative form
     void Compress(ScriptingEnvironment &scripting_environment,
                   std::vector<TurnRestriction> &turn_restrictions,
-                  std::vector<ConditionalTurnRestriction> &conditional_turn_restrictions,
                   std::vector<UnresolvedManeuverOverride> &maneuver_overrides);
 
     // Most ways are bidirectional, making the geometry in forward and backward direction the same,

include/extractor/node_restriction_map.hpp

@@ -0,0 +1,80 @@
+#ifndef OSRM_EXTRACTOR_NODE_RESTRICTION_MAP_HPP_
+#define OSRM_EXTRACTOR_NODE_RESTRICTION_MAP_HPP_
+
+#include "extractor/restriction.hpp"
+#include "restriction_graph.hpp"
+#include "util/typedefs.hpp"
+
+#include <boost/range/adaptor/filtered.hpp>
+#include <boost/unordered_map.hpp>
+
+#include <utility>
+#include <vector>
+
+namespace osrm
+{
+namespace extractor
+{
+
+// Allows easy check for whether a node restriction is present at a given intersection
+template <typename RestrictionFilter> class NodeRestrictionMap
+{
+  public:
+    NodeRestrictionMap(const RestrictionGraph &restriction_graph)
+        : restriction_graph(restriction_graph), index_filter(RestrictionFilter{})
+    {
+    }
+
+    // Find all restrictions applicable to (from,via,*) turns
+    auto Restrictions(NodeID from, NodeID via) const
+    {
+        return getRange(from, via) | boost::adaptors::filtered(index_filter);
+    };
+
+    // Find all restrictions applicable to (from,via,to) turns
+    auto Restrictions(NodeID from, NodeID via, NodeID to) const
+    {
+        const auto turnFilter = [this, to](const auto &restriction) {
+            return index_filter(restriction) && restriction->IsTurnRestricted(to);
+        };
+        return getRange(from, via) | boost::adaptors::filtered(turnFilter);
+    };
+
+  private:
+    RestrictionGraph::RestrictionRange getRange(NodeID from, NodeID via) const
+    {
+        const auto start_node_it = restriction_graph.start_edge_to_node.find({from, via});
+        if (start_node_it != restriction_graph.start_edge_to_node.end())
+        {
+            return restriction_graph.GetRestrictions(start_node_it->second);
+        }
+        return {};
+    }
+    const RestrictionGraph &restriction_graph;
+    const RestrictionFilter index_filter;
+};
+
+// Restriction filters to use as index defaults
+struct ConditionalOnly
+{
+    bool operator()(const TurnRestriction *restriction) const
+    {
+        return !restriction->IsUnconditional();
+    };
+};
+
+struct UnconditionalOnly
+{
+    bool operator()(const TurnRestriction *restriction) const
+    {
+        return restriction->IsUnconditional();
+    };
+};
+
+using RestrictionMap = NodeRestrictionMap<UnconditionalOnly>;
+using ConditionalRestrictionMap = NodeRestrictionMap<ConditionalOnly>;
+
+} // namespace extractor
+} // namespace osrm
+
+#endif // OSRM_EXTRACTOR_NODE_RESTRICTION_MAP_HPP_

include/extractor/nodes_of_way.hpp

@@ -0,0 +1,56 @@
+#ifndef NODES_OF_WAY_HPP
+#define NODES_OF_WAY_HPP
+
+#include "util/typedefs.hpp"
+
+#include <limits>
+#include <string>
+#include <vector>
+
+namespace osrm
+{
+namespace extractor
+{
+
+// NodesOfWay contains the ordered nodes of a way and provides convenience functions for getting
+// nodes in the first and last segments.
+struct NodesOfWay
+{
+    OSMWayID way_id;
+    std::vector<OSMNodeID> node_ids;
+
+    NodesOfWay() : way_id(SPECIAL_OSM_WAYID), node_ids{SPECIAL_OSM_NODEID, SPECIAL_OSM_NODEID} {}
+
+    NodesOfWay(OSMWayID w, std::vector<OSMNodeID> ns) : way_id(w), node_ids(std::move(ns)) {}
+
+    static NodesOfWay min_value() { return {MIN_OSM_WAYID, {MIN_OSM_NODEID, MIN_OSM_NODEID}}; }
+    static NodesOfWay max_value() { return {MAX_OSM_WAYID, {MAX_OSM_NODEID, MAX_OSM_NODEID}}; }
+
+    const OSMNodeID &first_segment_source_id() const
+    {
+        BOOST_ASSERT(!node_ids.empty());
+        return node_ids[0];
+    }
+
+    const OSMNodeID &first_segment_target_id() const
+    {
+        BOOST_ASSERT(node_ids.size() > 1);
+        return node_ids[1];
+    }
+
+    const OSMNodeID &last_segment_source_id() const
+    {
+        BOOST_ASSERT(node_ids.size() > 1);
+        return node_ids[node_ids.size() - 2];
+    }
+
+    const OSMNodeID &last_segment_target_id() const
+    {
+        BOOST_ASSERT(!node_ids.empty());
+        return node_ids[node_ids.size() - 1];
+    }
+};
+} // namespace extractor
+} // namespace osrm
+
+#endif /* NODES_OF_WAY_HPP */

include/extractor/restriction.hpp

@@ -30,17 +30,19 @@ struct InputNodeRestriction
     OSMWayID to;
 };
 
-// A restriction that uses a single via-way in between
+// A restriction that uses one or more via-way in between
 //
-// f - e - d
+// e - f - g
+//     |
+//     d
 //     |
 // a - b - c
 //
-// ab via be to ef -- no u turn
+// ab via bd,df to fe -- no u turn
 struct InputWayRestriction
 {
     OSMWayID from;
-    OSMWayID via;
+    std::vector<OSMWayID> via;
     OSMWayID to;
 };
 
@@ -57,6 +59,9 @@ struct InputTurnRestriction
     // keep in the same order as the turn restrictions below
     mapbox::util::variant<InputNodeRestriction, InputWayRestriction> node_or_way;
     bool is_only;
+    // We represent conditional and unconditional restrictions with the same structure.
+    // Unconditional restrictions will have empty conditions.
+    std::vector<util::OpeningHours> condition;
 
     OSMWayID From() const
     {
@@ -102,13 +107,15 @@ struct InputTurnRestriction
         return mapbox::util::get<InputNodeRestriction>(node_or_way);
     }
 };
-struct InputConditionalTurnRestriction : InputTurnRestriction
-{
-    std::vector<util::OpeningHours> condition;
-};
 
 // OSRM manages restrictions based on node IDs which refer to the last node along the edge. Note
 // that this has the side-effect of not allowing parallel edges!
+//
+// a - b - c
+//     |
+//     d
+//
+// ab via b to bd
 struct NodeRestriction
 {
     NodeID from;
@@ -131,39 +138,46 @@ struct NodeRestriction
 // compression happening in the graph creation process which would make it difficult to track
 // way-ids over a series of operations. Having access to the nodes directly allows look-up of the
 // edges in the processed structures
+//
+// e - f - g
+//     |
+//     d
+//     |
+// a - b - c
+//
+// ab via bd,df to fe -- no u turn
 struct WayRestriction
 {
-    // a way restriction in OSRM is essentially a dual node turn restriction;
-    //
-    // |     |
-    // c -x- b
-    // |     |
-    // d     a
-    //
-    // from ab via bxc to cd: no_uturn
-    //
-    // Technically, we would need only a,b,c,d to describe the full turn in terms of nodes. When
-    // parsing the relation, though, we do not know about the final representation in the node-based
-    // graph for the restriction. In case of a traffic light, for example, we might end up with bxc
-    // not being compressed to bc. For that reason, we need to maintain two node restrictions in
-    // case a way restrction is not fully collapsed
-    NodeRestriction in_restriction;
-    NodeRestriction out_restriction;
+    // A way restriction in OSRM needs to track all nodes that make up the via ways. Whilst most
+    // of these nodes will be removed by compression, some nodes will contain features that need to
+    // be considered when routing (e.g. intersections, nested restrictions, etc).
+    NodeID from;
+    std::vector<NodeID> via;
+    NodeID to;
+
+    // check if all parts of the restriction reference an actual node
+    bool Valid() const
+    {
+        return from != SPECIAL_NODEID && to != SPECIAL_NODEID && via.size() >= 2 &&
+               std::all_of(via.begin(), via.end(), [](NodeID i) { return i != SPECIAL_NODEID; });
+    };
 
     bool operator==(const WayRestriction &other) const
     {
-        return std::tie(in_restriction, out_restriction) ==
-               std::tie(other.in_restriction, other.out_restriction);
+        return std::tie(from, via, to) == std::tie(other.from, other.via, other.to);
     }
 };
 
 // Wrapper for turn restrictions that gives more information on its type / handles the switch
-// between node/way/multi-way restrictions
+// between node/way restrictions
 struct TurnRestriction
 {
     // keep in the same order as the turn restrictions above
     mapbox::util::variant<NodeRestriction, WayRestriction> node_or_way;
     bool is_only;
+    // We represent conditional and unconditional restrictions with the same structure.
+    // Unconditional restrictions will have empty conditions.
+    std::vector<util::OpeningHours> condition;
 
     // construction for NodeRestrictions
     explicit TurnRestriction(NodeRestriction node_restriction, bool is_only = false)
@@ -179,9 +193,40 @@ struct TurnRestriction
 
     explicit TurnRestriction()
     {
-        node_or_way = NodeRestriction{SPECIAL_EDGEID, SPECIAL_NODEID, SPECIAL_EDGEID};
+        node_or_way = NodeRestriction{SPECIAL_NODEID, SPECIAL_NODEID, SPECIAL_NODEID};
     }
 
+    NodeID To() const
+    {
+        return node_or_way.which() == RestrictionType::NODE_RESTRICTION
+                   ? mapbox::util::get<NodeRestriction>(node_or_way).to
+                   : mapbox::util::get<WayRestriction>(node_or_way).to;
+    }
+
+    NodeID From() const
+    {
+        return node_or_way.which() == RestrictionType::NODE_RESTRICTION
+                   ? mapbox::util::get<NodeRestriction>(node_or_way).from
+                   : mapbox::util::get<WayRestriction>(node_or_way).from;
+    }
+
+    NodeID FirstVia() const
+    {
+        if (node_or_way.which() == RestrictionType::NODE_RESTRICTION)
+        {
+            return mapbox::util::get<NodeRestriction>(node_or_way).via;
+        }
+        else
+        {
+            BOOST_ASSERT(!mapbox::util::get<WayRestriction>(node_or_way).via.empty());
+            return mapbox::util::get<WayRestriction>(node_or_way).via[0];
+        }
+    }
+
+    bool IsTurnRestricted(NodeID to) const { return is_only ? To() != to : To() == to; }
+
+    bool IsUnconditional() const { return condition.empty(); }
+
     WayRestriction &AsWayRestriction()
     {
         BOOST_ASSERT(node_or_way.which() == RestrictionType::WAY_RESTRICTION);
@@ -218,7 +263,7 @@ struct TurnRestriction
         if (node_or_way.which() == RestrictionType::WAY_RESTRICTION)
         {
             auto const &restriction = AsWayRestriction();
-            return restriction.in_restriction.Valid() && restriction.out_restriction.Valid();
+            return restriction.Valid();
         }
         else
         {
@@ -245,11 +290,6 @@ struct TurnRestriction
         }
     }
 };
-
-struct ConditionalTurnRestriction : TurnRestriction
-{
-    std::vector<util::OpeningHours> condition;
-};
 } // namespace extractor
 } // namespace osrm
 

include/extractor/restriction_compressor.hpp

@@ -16,8 +16,8 @@ namespace extractor
 struct NodeRestriction;
 struct TurnRestriction;
 
-// OSRM stores restrictions in the form node -> node -> node instead of way -> node -> way (or
-// way->way->way) as it is done in OSM. These restrictions need to match the state of graph
+// OSRM stores restrictions as node -> [node] -> node instead of way -> node -> way (or
+// way->[way]->way) as it is done in OSM. These restrictions need to match the state of graph
 // compression which we perform in the graph compressor that removes certain degree two nodes from
 // the graph (all but the ones with penalties/barriers, as of the state of writing).
 // Since this graph compression ins performed after creating the restrictions in the extraction
@@ -29,19 +29,22 @@ class RestrictionCompressor
 {
   public:
     RestrictionCompressor(std::vector<TurnRestriction> &restrictions,
-                          std::vector<ConditionalTurnRestriction> &conditional_turn_restrictions,
                           std::vector<UnresolvedManeuverOverride> &maneuver_overrides);
 
     // account for the compression of `from-via-to` into `from-to`
     void Compress(const NodeID from, const NodeID via, const NodeID to);
 
   private:
-    // a turn restriction is given as `from star via node to end`. Edges ending at `head` being
+    // A turn restriction is given as `from star via node to end`. Edges ending at `head` being
     // contracted move the head pointer to their respective head. Edges starting at tail move the
-    // tail values to their respective tails. Way turn restrictions are represented by two
-    // node-restrictions, so we can focus on them alone
-    boost::unordered_multimap<NodeID, NodeRestriction *> starts;
-    boost::unordered_multimap<NodeID, NodeRestriction *> ends;
+    // tail values to their respective tails.
+    // Via nodes that are compressed are removed from the restriction representation.
+    // We do not compress the first and last via nodes of a restriction as they act as
+    // entrance/exit points into the restriction graph. For a node restriction, the first and last
+    // via nodes are the same.
+    boost::unordered_multimap<NodeID, TurnRestriction *> starts;
+    boost::unordered_multimap<NodeID, TurnRestriction *> vias;
+    boost::unordered_multimap<NodeID, TurnRestriction *> ends;
 
     boost::unordered_multimap<NodeID, NodeBasedTurn *> maneuver_starts;
     boost::unordered_multimap<NodeID, NodeBasedTurn *> maneuver_ends;

include/extractor/restriction_filter.hpp

@@ -14,10 +14,8 @@ namespace extractor
 // To avoid handling invalid restrictions / creating unnecessary duplicate nodes for via-ways, we do
 // a pre-flight check for restrictions and remove all invalid restrictions from the data. Use as
 // `restrictions = removeInvalidRestrictions(std::move(restrictions))`
-std::vector<ConditionalTurnRestriction>
-removeInvalidRestrictions(std::vector<ConditionalTurnRestriction>,
-                          const util::NodeBasedDynamicGraph &);
-
+std::vector<TurnRestriction> removeInvalidRestrictions(std::vector<TurnRestriction>,
+                                                       const util::NodeBasedDynamicGraph &);
 } // namespace extractor
 } // namespace osrm
 

include/extractor/restriction_graph.hpp

@@ -0,0 +1,134 @@
+#ifndef OSRM_EXTRACTOR_RESTRICTION_GRAPH_HPP_
+#define OSRM_EXTRACTOR_RESTRICTION_GRAPH_HPP_
+
+#include <boost/assert.hpp>
+#include <boost/unordered_map.hpp>
+
+#include "extractor/restriction_filter.hpp"
+#include "util/node_based_graph.hpp"
+#include "util/typedefs.hpp"
+
+namespace osrm
+{
+namespace extractor
+{
+
+namespace restriction_graph_details
+{
+struct transferBuilder;
+struct pathBuilder;
+} // namespace restriction_graph_details
+
+struct RestrictionEdge
+{
+    NodeID node_based_to;
+    RestrictionID target;
+    bool is_transfer;
+};
+
+struct RestrictionNode
+{
+    size_t restrictions_begin_idx;
+    size_t num_restrictions;
+    size_t edges_begin_idx;
+    size_t num_edges;
+};
+
+/**
+ * The restriction graph is used to represent all possible restrictions within the routing graph.
+ * The graph uses an edge-based node representation. Each node represents a compressed
+ * node-based edge along a restriction path.
+ *
+ * Given a list of turn restrictions, the graph is created in multiple steps.
+ *
+ * INPUT
+ * a -> b -> d: no_e
+ * a -> b -> c: only_d
+ * b -> c -> d: only_f
+ * b -> c: no_g
+ * e -> b -> d: no_g
+ *
+ * Step 1: create a disjoint union of prefix trees for all restriction paths.
+ * The restriction instructions are added to the final node in its path.
+ *
+ * STEP 1
+ * (a,b) -> (b,d,[no_e])
+ *      \->(b,c,[only_d])
+ *
+ * (b,c,[no_g]) -> (c,d,[only_f])
+ * (e,b) -> (b,d,[no_g])
+ *
+ * Step 2: add transfers between restriction paths that overlap.
+ * We do this by traversing each restriction path, tracking where the suffix of our current path
+ * matches the prefix of any other. If it does, there's opportunity to transfer to the suffix
+ * restriction path *if* the transfer would not be restricted *and* that edge does not take us
+ * further on our current path. Nested restrictions are also added from any of the suffix paths.
+ *
+ * STEP 2
+ * (a,b) -> (b,d,[no_e])
+ *      \->(b,c,[only_d,no_g])
+ *                \
+ * (b,c,[no_g]) -> \-> (c,d,[only_f])
+ *
+ * (e,b) -> (b,d,[no_g])
+ * If a transfer applies to multiple suffix paths, we only add the edge to the largest suffix path.
+ * This ensures we correctly track all overlapping paths.
+ *
+ *
+ * Step 3: The nodes are split into
+ * start nodes - compressed edges that are entry points into a restriction path.
+ * via nodes - compressed edges that are intermediate steps along a restriction path.
+ * Start nodes and via nodes are indexed by the compressed node-based edge for easy retrieval
+ *
+ * STEP 3
+ * Start Node Index
+ * (a,b) => (a,b)
+ * (b,c) => (b,c,[no_g])
+ * (e,b) => (e,b)
+ *
+ * Via Nodes Index
+ * (b,c) => (b,c,[only_d,no_g])
+ * (b,d) => (b,d,[no_e]) , (b,d,[no_g])
+ * (c,d) => (c,d,[only_f])
+ *
+ * Duplicate Nodes:
+ * There is a 1-1 mapping between restriction graph via nodes and edge-based-graph duplicate nodes.
+ * This relationship is used in the creation of restrictions in the routing edge-based graph.
+ * */
+struct RestrictionGraph
+{
+    friend restriction_graph_details::pathBuilder;
+    friend restriction_graph_details::transferBuilder;
+    friend RestrictionGraph constructRestrictionGraph(const std::vector<TurnRestriction> &);
+
+    using EdgeRange = boost::iterator_range<std::vector<RestrictionEdge>::const_iterator>;
+    using RestrictionRange =
+        boost::iterator_range<std::vector<const TurnRestriction *>::const_iterator>;
+    using EdgeKey = std::pair<NodeID, NodeID>;
+
+    // Helper functions for iterating over node restrictions and edges
+    EdgeRange GetEdges(RestrictionID id) const;
+    RestrictionRange GetRestrictions(RestrictionID id) const;
+
+    // A compressed node-based edge can only have one start node in the restriction graph.
+    boost::unordered_map<EdgeKey, RestrictionID> start_edge_to_node{};
+    // A compressed node-based edge can have multiple via nodes in the restriction graph
+    // (as the compressed edge can appear in paths with different prefixes).
+    boost::unordered_multimap<EdgeKey, RestrictionID> via_edge_to_node{};
+    std::vector<RestrictionNode> nodes;
+    // TODO: Investigate reusing DynamicGraph. Currently it requires specific attributes
+    // (e.g. reversed, weight) that would not make sense for restrictions.
+    std::vector<RestrictionEdge> edges;
+    std::vector<const TurnRestriction *> restrictions;
+    size_t num_via_nodes{};
+
+  private:
+    RestrictionGraph() = default;
+};
+
+RestrictionGraph constructRestrictionGraph(const std::vector<TurnRestriction> &turn_restrictions);
+
+} // namespace extractor
+} // namespace osrm
+
+#endif // OSRM_EXTRACTOR_RESTRICTION_GRAPH_HPP_

include/extractor/restriction_index.hpp

@@ -1,101 +0,0 @@
-#ifndef OSRM_EXTRACTOR_RESTRICTION_INDEX_HPP_
-#define OSRM_EXTRACTOR_RESTRICTION_INDEX_HPP_
-
-#include "extractor/restriction.hpp"
-#include "util/typedefs.hpp"
-
-#include <boost/unordered_map.hpp>
-
-#include <utility>
-#include <vector>
-
-namespace osrm
-{
-namespace extractor
-{
-
-// allows easy check for whether a node intersection is present at a given intersection
-template <typename restriction_type> class RestrictionIndex
-{
-  public:
-    using value_type = restriction_type;
-
-    template <typename extractor_type>
-    RestrictionIndex(std::vector<restriction_type> &restrictions, extractor_type extractor);
-
-    bool IsIndexed(NodeID first, NodeID second) const;
-
-    auto Restrictions(NodeID first, NodeID second) const
-    {
-        return restriction_hash.equal_range(std::make_pair(first, second));
-    };
-
-    auto Size() const { return restriction_hash.size(); }
-
-  private:
-    boost::unordered_multimap<std::pair<NodeID, NodeID>, restriction_type *> restriction_hash;
-};
-
-template <typename restriction_type>
-template <typename extractor_type>
-RestrictionIndex<restriction_type>::RestrictionIndex(std::vector<restriction_type> &restrictions,
-                                                     extractor_type extractor)
-{
-    // build a multi-map
-    for (auto &restriction : restrictions)
-        restriction_hash.insert(std::make_pair(extractor(restriction), &restriction));
-}
-
-template <typename restriction_type>
-bool RestrictionIndex<restriction_type>::IsIndexed(const NodeID first, const NodeID second) const
-{
-    return restriction_hash.count(std::make_pair(first, second));
-}
-
-struct IndexNodeByFromAndVia
-{
-    std::pair<NodeID, NodeID> operator()(const TurnRestriction &restriction)
-    {
-        const auto &node = restriction.AsNodeRestriction();
-        return std::make_pair(node.from, node.via);
-    };
-};
-
-// check wheter a turn is restricted within a restriction_index
-template <typename restriction_map_type>
-std::pair<bool, typename restriction_map_type::value_type *>
-isRestricted(const NodeID from,
-             const NodeID via,
-             const NodeID to,
-             const restriction_map_type &restriction_map)
-{
-    const auto range = restriction_map.Restrictions(from, via);
-
-    // check if a given node_restriction is targeting node
-    const auto to_is_restricted = [to](const auto &pair) {
-        const auto &restriction = *pair.second;
-        if (restriction.Type() == RestrictionType::NODE_RESTRICTION)
-        {
-            auto const &as_node = restriction.AsNodeRestriction();
-            auto const restricted = restriction.is_only ? (to != as_node.to) : (to == as_node.to);
-
-            return restricted;
-        }
-        return false;
-    };
-
-    auto itr = std::find_if(range.first, range.second, to_is_restricted);
-
-    if (itr != range.second)
-        return {true, itr->second};
-    else
-        return {false, NULL};
-}
-
-using RestrictionMap = RestrictionIndex<TurnRestriction>;
-using ConditionalRestrictionMap = RestrictionIndex<ConditionalTurnRestriction>;
-
-} // namespace extractor
-} // namespace osrm
-
-#endif // OSRM_EXTRACTOR_RESTRICTION_INDEX_HPP_

include/extractor/restriction_parser.hpp

@@ -44,8 +44,7 @@ class RestrictionParser
     RestrictionParser(bool use_turn_restrictions,
                       bool parse_conditionals,
                       std::vector<std::string> &restrictions);
-    boost::optional<InputConditionalTurnRestriction>
-    TryParse(const osmium::Relation &relation) const;
+    boost::optional<InputTurnRestriction> TryParse(const osmium::Relation &relation) const;
 
   private:
     bool ShouldIgnoreRestriction(const std::string &except_tag_string) const;

include/extractor/scripting_environment.hpp

@@ -68,7 +68,7 @@ class ScriptingEnvironment
                     const ExtractionRelationContainer &relations,
                     std::vector<std::pair<const osmium::Node &, ExtractionNode>> &resulting_nodes,
                     std::vector<std::pair<const osmium::Way &, ExtractionWay>> &resulting_ways,
-                    std::vector<InputConditionalTurnRestriction> &resulting_restrictions,
+                    std::vector<InputTurnRestriction> &resulting_restrictions,
                     std::vector<InputManeuverOverride> &resulting_maneuver_overrides) = 0;
 
     virtual bool HasLocationDependentData() const = 0;

include/extractor/scripting_environment_lua.hpp

@@ -92,7 +92,7 @@ class Sol2ScriptingEnvironment final : public ScriptingEnvironment
                     const ExtractionRelationContainer &relations,
                     std::vector<std::pair<const osmium::Node &, ExtractionNode>> &resulting_nodes,
                     std::vector<std::pair<const osmium::Way &, ExtractionWay>> &resulting_ways,
-                    std::vector<InputConditionalTurnRestriction> &resulting_restrictions,
+                    std::vector<InputTurnRestriction> &resulting_restrictions,
                     std::vector<InputManeuverOverride> &resulting_maneuver_overrides) override;
 
     bool HasLocationDependentData() const override { return !location_dependent_data.empty(); }

include/extractor/way_restriction_map.hpp

@@ -8,82 +8,66 @@
 #include <boost/unordered_map.hpp>
 
 #include "extractor/restriction.hpp"
-#include "extractor/restriction_index.hpp"
+#include "extractor/restriction_graph.hpp"
 #include "util/integer_range.hpp"
 #include "util/typedefs.hpp"
 
-// Given the compressed representation of via-way turn restrictions, we provide a fast access into
-// the restrictions to indicate which turns may be restricted due to a way in between
 namespace osrm
 {
 namespace extractor
 {
 
-// The WayRestrictionMap uses ConditionalTurnRestrictions in general. Most restrictions will have
-// empty conditions, though.
+// Given the compressed representation of via-way turn restrictions, we provide a fast access into
+// the restrictions to indicate which turns may be restricted due to a way in between.
 class WayRestrictionMap
 {
   public:
-    struct ViaWay
+    struct ViaEdge
     {
         NodeID from;
         NodeID to;
     };
-    WayRestrictionMap(const std::vector<ConditionalTurnRestriction> &conditional_restrictions);
+    WayRestrictionMap(const RestrictionGraph &restriction_graph);
 
-    // Check if an edge between two nodes is a restricted turn. The check needs to be performed to
+    // Check if an edge between two nodes is part of a via-way. The check needs to be performed to
     // find duplicated nodes during the creation of edge-based-edges
-    bool IsViaWay(const NodeID from, const NodeID to) const;
+    bool IsViaWayEdge(NodeID from, NodeID to) const;
 
-    // Every via-way results in a duplicated node that is required in the edge-based-graph. This
-    // count is essentially the same as the number of valid via-way restrictions (except for
-    // non-only restrictions that share the same in/via combination)
+    // There is a bijection between restriction graph via-nodes and edge-based duplicated nodes.
+    // This counts the number of duplicated nodes contributed by the way restrictions.
     std::size_t NumberOfDuplicatedNodes() const;
 
-    // Returns a representative for each duplicated node, consisting of the representative ID (first
-    // ID of the nodes restrictions) and the from/to vertices of the via-way
-    // This is used to construct edge based nodes that act as intermediate nodes.
-    std::vector<ViaWay> DuplicatedNodeRepresentatives() const;
+    // For each restriction graph via-node, we return its node-based edge representation (from,to).
+    // This is used to create the duplicate node in the edge based graph.
+    std::vector<ViaEdge> DuplicatedViaEdges() const;
 
-    // Access all duplicated NodeIDs for a set of nodes indicating a via way
-    std::vector<DuplicatedNodeID> DuplicatedNodeIDs(const NodeID from, const NodeID to) const;
+    // Access all duplicated NodeIDs from the restriction graph via-node represented by (from,to)
+    std::vector<DuplicatedNodeID> DuplicatedNodeIDs(NodeID from, NodeID to) const;
 
-    // check whether a turn onto a given node is restricted, when coming from a duplicated node
-    bool IsRestricted(DuplicatedNodeID duplicated_node, const NodeID to) const;
-    // Get the restriction resulting in ^ IsRestricted. Requires IsRestricted to evaluate to true
-    const ConditionalTurnRestriction &GetRestriction(DuplicatedNodeID duplicated_node,
-                                                     const NodeID to) const;
+    // Check whether a turn onto a given node is restricted, when coming from a duplicated node
+    bool IsRestricted(DuplicatedNodeID duplicated_node, NodeID to) const;
 
-    // changes edge_based_node to the correct duplicated_node_id in case node_based_from,
-    // node_based_via, node_based_to can be identified with a restriction group
-    NodeID RemapIfRestricted(const NodeID edge_based_node,
-                             const NodeID node_based_from,
-                             const NodeID node_based_via,
-                             const NodeID node_based_to,
-                             const NodeID number_of_edge_based_nodes) const;
+    // Get the restrictions resulting in ^ IsRestricted. Requires IsRestricted to evaluate to true
+    std::vector<const TurnRestriction *> GetRestrictions(DuplicatedNodeID duplicated_node,
+                                                         NodeID to) const;
+
+    // Changes edge_based_node to the correct duplicated_node_id in case node_based_from,
+    // node_based_via, node_based_to can be identified as the start of a way restriction.
+    NodeID RemapIfRestrictionStart(NodeID edge_based_node,
+                                   NodeID node_based_from,
+                                   NodeID node_based_via,
+                                   NodeID node_based_to,
+                                   NodeID number_of_edge_based_nodes) const;
+
+    // Changes edge_based_node to the correct duplicated_node_id in case node_based_from,
+    // node_based_via, node_based_to can be identified as successive via steps of a way restriction.
+    NodeID RemapIfRestrictionVia(NodeID edge_based_target_node,
+                                 NodeID edge_based_via_node,
+                                 NodeID node_based_to,
+                                 NodeID number_of_edge_based_nodes) const;
 
   private:
-    DuplicatedNodeID AsDuplicatedNodeID(const RestrictionID restriction_id) const;
-
-    // access all restrictions that have the same starting way and via way. Any duplicated node
-    // represents the same in-way + via-way combination. This vector contains data about all
-    // restrictions and their assigned duplicated nodes. It indicates the minimum restriciton ID
-    // that is represented by the next node. The ID of a node is defined as the position of the
-    // lower bound of the restrictions ID within this array
-    //
-    // a - b
-    //     |
-    // y - c - x
-    //
-    // restriction nodes | restriction id
-    // a - b - c - x : 5
-    // a - b - c - y : 6
-    //
-    //                    EBN: 0 . | 2 | 3 | 4 ...
-    // duplicated node groups: ... | 5 | 7 | ...
-    std::vector<DuplicatedNodeID> duplicated_node_groups;
-    std::vector<ConditionalTurnRestriction> restriction_data;
-    RestrictionIndex<ConditionalTurnRestriction> restriction_starts;
+    const RestrictionGraph &restriction_graph;
 };
 
 } // namespace extractor