Avoid copy of std::function-based callback in path unpacking (#6895)

* Avoid copy of std::function-based callback in path unpacking

* Fix formatting

* Update CHANGELOG.md

Author: DennisOSRM

CHANGELOG.md

@@ -20,6 +20,7 @@
     - NodeJS:
       - CHANGED: Use node-api instead of NAN. [#6452](https://github.com/Project-OSRM/osrm-backend/pull/6452)
     - Misc:
+      - CHANGED: Avoid copy of std::function-based callback in path unpacking [#6895](https://github.com/Project-OSRM/osrm-backend/pull/6895)
       - CHANGED: Replace boost::hash by std::hash [#6892](https://github.com/Project-OSRM/osrm-backend/pull/6892)
       - CHANGED: Partial fix migration from boost::optional to std::optional [#6551](https://github.com/Project-OSRM/osrm-backend/issues/6551)
       - CHANGED: Update Conan Boost version to 1.85.0. [#6868](https://github.com/Project-OSRM/osrm-backend/pull/6868)

include/engine/datafacade/algorithm_datafacade.hpp

@@ -55,7 +55,7 @@ template <> class AlgorithmDataFacade<CH>
 
     virtual EdgeID FindSmallestEdge(const NodeID edge_based_node_from,
                                     const NodeID edge_based_node_to,
-                                    const std::function<bool(EdgeData)> filter) const = 0;
+                                    const std::function<bool(const EdgeData &)> &filter) const = 0;
 };
 
 template <> class AlgorithmDataFacade<MLD>

include/engine/datafacade/contiguous_internalmem_datafacade.hpp

@@ -130,9 +130,10 @@ class ContiguousInternalMemoryAlgorithmDataFacade<CH> : public datafacade::Algor
             edge_based_node_from, edge_based_node_to, result);
     }
 
-    EdgeID FindSmallestEdge(const NodeID edge_based_node_from,
-                            const NodeID edge_based_node_to,
-                            std::function<bool(EdgeData)> filter) const override final
+    EdgeID
+    FindSmallestEdge(const NodeID edge_based_node_from,
+                     const NodeID edge_based_node_to,
+                     const std::function<bool(const EdgeData &)> &filter) const override final
     {
         return m_query_graph.FindSmallestEdge(edge_based_node_from, edge_based_node_to, filter);
     }

unit_tests/mocks/mock_datafacade.hpp

@@ -238,9 +238,10 @@ class MockAlgorithmDataFacade<engine::datafacade::CH>
         return SPECIAL_EDGEID;
     }
 
-    EdgeID FindSmallestEdge(const NodeID /* from */,
-                            const NodeID /* to */,
-                            std::function<bool(EdgeData)> /* filter */) const override
+    EdgeID
+    FindSmallestEdge(const NodeID /* from */,
+                     const NodeID /* to */,
+                     const std::function<bool(const EdgeData &)> & /* filter */) const override
     {
         return SPECIAL_EDGEID;
     }