From 92ffa60ae76b91b1e91a9161f1d4d22bded5c45f Mon Sep 17 00:00:00 2001
From: Todd Grunke <toddgrun@microsoft.com>
Date: Wed, 25 Jun 2025 15:21:03 -0700
Subject: [PATCH] Small but trivial allocation improvement in
 FileWatchedReferenceFactory.StopWatchingReference

String.Concat shows up as 0.3% of allocations in cohost scrolling razor speedometer test. Just moved the concatenation closer to where it's used, as I see it not used over 95% of the time this method is called.
---
 .../FileWatchedPortableExecutableReferenceFactory.cs           | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Workspaces/Core/Portable/Workspace/ProjectSystem/FileWatchedPortableExecutableReferenceFactory.cs b/src/Workspaces/Core/Portable/Workspace/ProjectSystem/FileWatchedPortableExecutableReferenceFactory.cs
index f68e3fa6861e..afe95e4b871b 100644
--- a/src/Workspaces/Core/Portable/Workspace/ProjectSystem/FileWatchedPortableExecutableReferenceFactory.cs
+++ b/src/Workspaces/Core/Portable/Workspace/ProjectSystem/FileWatchedPortableExecutableReferenceFactory.cs
@@ -142,7 +142,6 @@ public void StopWatchingReference(string fullFilePath, TReference? referenceToTr
     {
         lock (_gate)
         {
-            var disposalLocation = callerFilePath + ", line " + callerLineNumber;
             if (!_referenceFileWatchingTokens.TryGetValue(fullFilePath, out var watchedFileReference))
             {
                 if (referenceToTrack != null)
@@ -167,6 +166,8 @@ public void StopWatchingReference(string fullFilePath, TReference? referenceToTr
 
                 if (referenceToTrack != null)
                 {
+                    var disposalLocation = callerFilePath + ", line " + callerLineNumber;
+
                     _previousDisposalLocations.Remove(referenceToTrack);
                     _previousDisposalLocations.Add(referenceToTrack, disposalLocation);
                 }