From aca98b8a5e83df7cdf922fed4c6add0dc4036696 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Breitbart?= <jerch@rockborn.de>
Date: Thu, 20 Aug 2026 16:32:14 +0200
Subject: [PATCH 1/2] silence noisy code for most trim events

---
 src/common/services/DecorationService.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/common/services/DecorationService.ts b/src/common/services/DecorationService.ts
index ea9b7fb14..49e85729d 100644
--- a/src/common/services/DecorationService.ts
+++ b/src/common/services/DecorationService.ts
@@ -214,7 +214,7 @@ export class DecorationLineCache extends Disposable {
   }
 
   private _handleBufferLinesTrim(amount: number): void {
-    if (amount <= 0) {
+    if (amount <= 0 || !this._decorationsByLine.size) {
       return;
     }
     const newMap = new Map<number, IInternalDecoration[]>();

From bc62843844b992700a26d4ba8536f94e0fb5cb6b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Breitbart?= <jerch@rockborn.de>
Date: Thu, 20 Aug 2026 16:32:41 +0200
Subject: [PATCH 2/2] optimize Event.fire

---
 src/common/Event.ts | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/src/common/Event.ts b/src/common/Event.ts
index 88417fc83..9f7df4f9c 100644
--- a/src/common/Event.ts
+++ b/src/common/Event.ts
@@ -27,11 +27,13 @@ export class Emitter<T> {
       }
 
       const entry = { fn: listener, thisArgs };
+      this._listeners = this._listeners.slice();
       this._listeners.push(entry);
 
       const result = toDisposable(() => {
         const idx = this._listeners.indexOf(entry);
         if (idx !== -1) {
+          this._listeners = this._listeners.slice();
           this._listeners.splice(idx, 1);
         }
       });
@@ -50,23 +52,16 @@ export class Emitter<T> {
   }
 
   public fire(event: T): void {
-    if (this._disposed) {
+    if (this._disposed || !this._listeners.length) {
       return;
     }
-    switch (this._listeners.length) {
-      case 0: return;
-      case 1: {
-        const { fn, thisArgs } = this._listeners[0];
-        fn.call(thisArgs, event);
-        return;
-      }
-      default: {
-        // Snapshot listeners to allow modifications during iteration (2+ listeners)
-        const listeners = this._listeners.slice();
-        for (const { fn, thisArgs } of listeners) {
-          fn.call(thisArgs, event);
-        }
-      }
+    if (this._listeners.length === 1) {
+      this._listeners[0].fn.call(this._listeners[0].thisArgs, event);
+      return;
+    }
+    const listeners = this._listeners;
+    for (let i = 0, len = listeners.length; i < len; ++i) {
+      listeners[i].fn.call(listeners[i].thisArgs, event);
     }
   }