Optimise path distance calculation in MLD map matching (#6876)

.github/workflows/osrm-backend.yml

@@ -518,7 +518,8 @@ jobs:
         make --jobs=${JOBS} benchmarks
         ./src/benchmarks/alias-bench
         ./src/benchmarks/json-render-bench ../src/benchmarks/portugal_to_korea.json
-        ./src/benchmarks/match-bench ../test/data/ch/monaco.osrm
+        ./src/benchmarks/match-bench ../test/data/ch/monaco.osrm ch
+        ./src/benchmarks/match-bench ../test/data/mld/monaco.osrm mld
         ./src/benchmarks/packedvector-bench
         ./src/benchmarks/rtree-bench ../test/data/monaco.osrm.ramIndex ../test/data/monaco.osrm.fileIndex ../test/data/monaco.osrm.nbg_nodes
         popd

CHANGELOG.md

@@ -47,6 +47,8 @@
       - FIXED: Fix bug when searching for maneuver overrides [#6739](https://github.com/Project-OSRM/osrm-backend/pull/6739)
       - FIXED: Remove force-loop checks for routes with u-turns [#6858](https://github.com/Project-OSRM/osrm-backend/pull/6858)
       - FIXED: Correctly check runtime search conditions for forcing routing steps [#6866](https://github.com/Project-OSRM/osrm-backend/pull/6866)
+    - Map Matching:
+      - CHANGED: Optimise path distance calculation in MLD map matching. [#6876](https://github.com/Project-OSRM/osrm-backend/pull/6876)
     - Debug tiles:
       - FIXED: Ensure speed layer features have unique ids. [#6726](https://github.com/Project-OSRM/osrm-backend/pull/6726)
 

include/engine/routing_algorithms/routing_base_mld.hpp

@@ -613,11 +613,38 @@ double getNetworkDistance(SearchEngineData<Algorithm> &engine_working_data,
         return std::numeric_limits<double>::max();
     }
 
-    std::vector<PathData> unpacked_path;
+    BOOST_ASSERT(unpacked_nodes.size() >= 1);
 
-    annotatePath(facade, endpoints, unpacked_nodes, unpacked_edges, unpacked_path);
+    EdgeDistance distance = {0.0};
 
-    return getPathDistance(facade, unpacked_path, source_phantom, target_phantom);
+    if (source_phantom.forward_segment_id.id == unpacked_nodes.front())
+    {
+        BOOST_ASSERT(source_phantom.forward_segment_id.enabled);
+        distance = EdgeDistance{0} - source_phantom.GetForwardDistance();
+    }
+    else if (source_phantom.reverse_segment_id.id == unpacked_nodes.front())
+    {
+        BOOST_ASSERT(source_phantom.reverse_segment_id.enabled);
+        distance = EdgeDistance{0} - source_phantom.GetReverseDistance();
+    }
+
+    for (size_t index = 0; index < unpacked_nodes.size() - 1; ++index)
+    {
+        distance += facade.GetNodeDistance(unpacked_nodes[index]);
+    }
+
+    if (target_phantom.forward_segment_id.id == unpacked_nodes.back())
+    {
+        BOOST_ASSERT(target_phantom.forward_segment_id.enabled);
+        distance += target_phantom.GetForwardDistance();
+    }
+    else if (target_phantom.reverse_segment_id.id == unpacked_nodes.back())
+    {
+        BOOST_ASSERT(target_phantom.reverse_segment_id.enabled);
+        distance += target_phantom.GetReverseDistance();
+    }
+
+    return from_alias<double>(distance);
 }
 
 } // namespace osrm::engine::routing_algorithms::mld

src/benchmarks/match.cpp

@@ -1,3 +1,4 @@
+#include "engine/engine_config.hpp"
 #include "util/timing_util.hpp"
 
 #include "osrm/match_parameters.hpp"
@@ -32,6 +33,8 @@ try
     // Configure based on a .osrm base path, and no datasets in shared mem from osrm-datastore
     EngineConfig config;
     config.storage_config = {argv[1]};
+    config.algorithm = (argc > 2 && std::string{argv[2]} == "mld") ? EngineConfig::Algorithm::MLD
+                                                                   : EngineConfig::Algorithm::CH;
     config.use_shared_memory = false;
 
     // Routing machine with several services (such as Route, Table, Nearest, Trip, Match)