From e28c230c526a944d8a8a46c03be3320dcbd2d6d0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Habinshuti?= <clhabins@microsoft.com>
Date: Tue, 23 Jan 2024 11:30:43 +0300
Subject: [PATCH] Optimize `ODataPathExtensions.GetNavigationSource` (#1161)

* Optimize GetNavigationSource source

* Use >= 0 instead of > -1
---
 .../Routing/ODataPathExtensions.cs            | 55 ++++++++++++++++++-
 1 file changed, 52 insertions(+), 3 deletions(-)

diff --git a/src/Microsoft.AspNetCore.OData/Routing/ODataPathExtensions.cs b/src/Microsoft.AspNetCore.OData/Routing/ODataPathExtensions.cs
index e11951499..a41af0ff6 100644
--- a/src/Microsoft.AspNetCore.OData/Routing/ODataPathExtensions.cs
+++ b/src/Microsoft.AspNetCore.OData/Routing/ODataPathExtensions.cs
@@ -77,9 +77,58 @@ public static IEdmNavigationSource GetNavigationSource(this ODataPath path)
                 throw Error.ArgumentNull(nameof(path));
             }
 
-            ODataPathNavigationSourceHandler handler = new ODataPathNavigationSourceHandler();
-            path.WalkWith(handler);
-            return handler.NavigationSource;
+            for (int i = path.Count - 1; i >= 0; --i)
+            {
+                ODataPathSegment segment = path[i];
+                if (segment is EntitySetSegment entitySetSegment)
+                {
+                    return entitySetSegment.EntitySet;
+                }
+
+                if (segment is KeySegment keySegment)
+                {
+                    return keySegment.NavigationSource;
+                }
+
+                if (segment is NavigationPropertyLinkSegment navigationPropertyLinkSegment)
+                {
+                    return navigationPropertyLinkSegment.NavigationSource;
+                }
+
+                if (segment is NavigationPropertySegment navigationPropertySegment)
+                {
+                    return navigationPropertySegment.NavigationSource;
+                }
+
+                if (segment is OperationImportSegment operationImportSegment)
+                {
+                    return operationImportSegment.EntitySet;
+                }
+
+                if (segment is OperationSegment operationSegment)
+                {
+                    return operationSegment.EntitySet;
+                }
+
+                if (segment is SingletonSegment singleton)
+                {
+                    return singleton.Singleton;
+                }
+
+                if (segment is TypeSegment typeSegment)
+                {
+                    return typeSegment.NavigationSource;
+                }
+
+                if (segment is PropertySegment)
+                {
+                    continue;
+                }
+
+                return null;
+            }
+
+            return null;
         }
 
         /// <summary>