From acbc02b288a9a9ac26e3e9f04765952b42fbb574 Mon Sep 17 00:00:00 2001
From: Jakub Majocha <1760221+majocha@users.noreply.github.com>
Date: Fri, 26 Sep 2025 11:51:36 +0200
Subject: [PATCH 1/2] show cache metrics in output pane

---
 .../src/FSharp.Editor/Common/DebugHelpers.fs  | 35 +++++++++----------
 .../LanguageService/LanguageService.fs        |  8 +++++
 2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/vsintegration/src/FSharp.Editor/Common/DebugHelpers.fs b/vsintegration/src/FSharp.Editor/Common/DebugHelpers.fs
index 6ffb3cd7d95..51cdd83f8fa 100644
--- a/vsintegration/src/FSharp.Editor/Common/DebugHelpers.fs
+++ b/vsintegration/src/FSharp.Editor/Common/DebugHelpers.fs
@@ -31,6 +31,7 @@ open Config
 open System.Diagnostics.Metrics
 open System.Text
 open Microsoft.VisualStudio.Threading
+open Microsoft.VisualStudio.FSharp.Editor.CancellableTasks
 
 module FSharpOutputPane =
 
@@ -56,29 +57,17 @@ module FSharpOutputPane =
     let private log logType msg =
         task {
             System.Diagnostics.Trace.TraceInformation(msg)
-            let time = DateTime.Now.ToString("hh:mm:ss tt")
-
             let! pane = pane.GetValueAsync()
 
             do! ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync()
 
             match logType with
-            | LogType.Message ->
-                String.Format("[{0}{1}] {2}{3}", "", time, msg, Environment.NewLine)
-                |> pane.OutputStringThreadSafe
-                |> ignore
-            | LogType.Info ->
-                String.Format("[{0}{1}] {2}{3}", "INFO ", time, msg, Environment.NewLine)
-                |> pane.OutputStringThreadSafe
-                |> ignore
-            | LogType.Warn ->
-                String.Format("[{0}{1}] {2}{3}", "WARN ", time, msg, Environment.NewLine)
-                |> pane.OutputStringThreadSafe
-                |> ignore
-            | LogType.Error ->
-                String.Format("[{0}{1}] {2}{3}", "ERROR ", time, msg, Environment.NewLine)
-                |> pane.OutputStringThreadSafe
-                |> ignore
+            | LogType.Message -> $"{msg}"
+            | LogType.Info -> $"[INFO] {msg}"
+            | LogType.Warn -> $"[WARN] {msg}"
+            | LogType.Error -> $"[ERROR] {msg}"
+            |> pane.OutputStringThreadSafe
+            |> ignore
         }
         |> ignore
 
@@ -102,6 +91,7 @@ module FSharpOutputPane =
 
 module FSharpServiceTelemetry =
     open FSharp.Compiler.Caches
+    open System.Threading.Tasks
 
     let listen filter =
         let indent (activity: Activity) =
@@ -130,6 +120,15 @@ module FSharpServiceTelemetry =
 
         ActivitySource.AddActivityListener(listener)
 
+    let periodicallyDisplayCacheStats =
+        cancellableTask {
+            use _ = CacheMetrics.ListenToAll()
+
+            while true do
+                do! Task.Delay(TimeSpan.FromSeconds 10.0)
+                FSharpOutputPane.logMsg (CacheMetrics.StatsToString())
+        }
+
 #if DEBUG
     open OpenTelemetry.Resources
     open OpenTelemetry.Trace
diff --git a/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs b/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs
index 08318997477..6ceafb3eae8 100644
--- a/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs
+++ b/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs
@@ -411,6 +411,14 @@ type internal FSharpPackage() as this =
                 |> CancellableTask.startAsTask cancellationToken)
         )
 
+#if DEBUG
+    override _.RegisterOnAfterPackageLoadedAsyncWork (afterPackageLoadedTasks: PackageLoadTasks) = 
+        afterPackageLoadedTasks.AddTask(false, fun _ _ -> task {
+            DebugHelpers.FSharpServiceTelemetry.periodicallyDisplayCacheStats
+            |> CancellableTask.start this.DisposalToken |> ignore
+        })
+#endif
+
     override _.RoslynLanguageName = FSharpConstants.FSharpLanguageName
     (*override this.CreateWorkspace() = this.ComponentModel.GetService<VisualStudioWorkspaceImpl>() *)
     override this.CreateLanguageService() = FSharpLanguageService(this)

From 0be850b50689a14e7547b7a572d7cf814808e416 Mon Sep 17 00:00:00 2001
From: Jakub Majocha <1760221+majocha@users.noreply.github.com>
Date: Fri, 26 Sep 2025 12:25:27 +0200
Subject: [PATCH 2/2] format

---
 .../LanguageService/LanguageService.fs            | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs b/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs
index 6ceafb3eae8..92b6979883a 100644
--- a/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs
+++ b/vsintegration/src/FSharp.Editor/LanguageService/LanguageService.fs
@@ -412,11 +412,16 @@ type internal FSharpPackage() as this =
         )
 
 #if DEBUG
-    override _.RegisterOnAfterPackageLoadedAsyncWork (afterPackageLoadedTasks: PackageLoadTasks) = 
-        afterPackageLoadedTasks.AddTask(false, fun _ _ -> task {
-            DebugHelpers.FSharpServiceTelemetry.periodicallyDisplayCacheStats
-            |> CancellableTask.start this.DisposalToken |> ignore
-        })
+    override _.RegisterOnAfterPackageLoadedAsyncWork(afterPackageLoadedTasks: PackageLoadTasks) =
+        afterPackageLoadedTasks.AddTask(
+            false,
+            fun _ _ ->
+                task {
+                    DebugHelpers.FSharpServiceTelemetry.periodicallyDisplayCacheStats
+                    |> CancellableTask.start this.DisposalToken
+                    |> ignore
+                }
+        )
 #endif
 
     override _.RoslynLanguageName = FSharpConstants.FSharpLanguageName