From 51b74a99aa5a7f04693455e4fb758feb4f939b73 Mon Sep 17 00:00:00 2001
From: Dennis Luxen <info@project-osrm.org>
Date: Thu, 23 May 2024 18:51:51 +0200
Subject: [PATCH] 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
---
 CHANGELOG.md                                               | 1 +
 include/engine/datafacade/algorithm_datafacade.hpp         | 2 +-
 .../datafacade/contiguous_internalmem_datafacade.hpp       | 7 ++++---
 unit_tests/mocks/mock_datafacade.hpp                       | 7 ++++---
 4 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 302b7cc9a..daa7c1d5e 100644
--- a/CHANGELOG.md
+++ b/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)
diff --git a/include/engine/datafacade/algorithm_datafacade.hpp b/include/engine/datafacade/algorithm_datafacade.hpp
index 7965784bc..192d024fc 100644
--- a/include/engine/datafacade/algorithm_datafacade.hpp
+++ b/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>
diff --git a/include/engine/datafacade/contiguous_internalmem_datafacade.hpp b/include/engine/datafacade/contiguous_internalmem_datafacade.hpp
index ac9497eb0..b6e1532d3 100644
--- a/include/engine/datafacade/contiguous_internalmem_datafacade.hpp
+++ b/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);
     }
diff --git a/unit_tests/mocks/mock_datafacade.hpp b/unit_tests/mocks/mock_datafacade.hpp
index a0de5a245..dc2541713 100644
--- a/unit_tests/mocks/mock_datafacade.hpp
+++ b/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;
     }