From 702cef384c673f82e1ab6b648ddd56d2096776cb Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Sun, 31 May 2026 07:43:29 -0700
Subject: [PATCH] perf: bound notification cooldown tracking (#4194)

---
 src/main/ipc/notifications.test.ts | 32 +++++++++++++++++++++++++++++
 src/main/ipc/notifications.ts      | 33 ++++++++++++++++++++++--------
 2 files changed, 57 insertions(+), 8 deletions(-)

diff --git a/src/main/ipc/notifications.test.ts b/src/main/ipc/notifications.test.ts
index 1fedb2a7a21..e2785ce73f5 100644
--- a/src/main/ipc/notifications.test.ts
+++ b/src/main/ipc/notifications.test.ts
@@ -965,6 +965,38 @@ describe('registerNotificationHandlers', () => {
     expect(notificationShowMock).toHaveBeenCalledTimes(2)
   })
 
+  it('bounds notification cooldown keys during unique worktree bursts', () => {
+    notificationIsSupportedMock.mockReturnValue(false)
+    registerNotificationHandlers({
+      getSettings: () => ({
+        notifications: {
+          enabled: true,
+          agentTaskComplete: true,
+          terminalBell: true,
+          suppressWhenFocused: false
+        }
+      })
+    } as never)
+
+    const handler = getDispatchHandler()
+    for (let i = 0; i < 75; i++) {
+      expect(handler({}, { source: 'terminal-bell', worktreeId: `repo::wt-${i}` })).toEqual({
+        delivered: false,
+        reason: 'not-supported'
+      })
+    }
+
+    expect(handler({}, { source: 'terminal-bell', worktreeId: 'repo::wt-0' })).toEqual({
+      delivered: false,
+      reason: 'not-supported'
+    })
+    expect(handler({}, { source: 'terminal-bell', worktreeId: 'repo::wt-74' })).toEqual({
+      delivered: false,
+      reason: 'cooldown'
+    })
+    expect(notificationCtorMock).not.toHaveBeenCalled()
+  })
+
   it('deduplicates agent-task-complete and terminal-bell for the same worktree', () => {
     registerNotificationHandlers({
       getSettings: () => ({
diff --git a/src/main/ipc/notifications.ts b/src/main/ipc/notifications.ts
index a7b6e95029e..f35be06f73f 100644
--- a/src/main/ipc/notifications.ts
+++ b/src/main/ipc/notifications.ts
@@ -25,6 +25,7 @@ import { buildNotificationOptions } from './notification-options'
 import { parsePaneKey } from '../../shared/stable-pane-id'
 
 const NOTIFICATION_COOLDOWN_MS = 5000
+const MAX_RECENT_NOTIFICATION_KEYS = 50
 const NOTIFICATION_DISPLAY_CONFIRMATION_TIMEOUT_MS = 2500
 const NOTIFICATION_RELEASE_FALLBACK_MS = 5 * 60 * 1000
 const MAX_NOTIFICATION_SOUND_BYTES = 10 * 1024 * 1024
@@ -175,6 +176,26 @@ function logNativeNotificationFailure(context: string, error?: string): void {
   )
 }
 
+function pruneRecentNotifications(recentNotifications: Map<string, number>, now: number): void {
+  if (recentNotifications.size <= MAX_RECENT_NOTIFICATION_KEYS) {
+    return
+  }
+
+  for (const [key, ts] of recentNotifications) {
+    if (now - ts >= NOTIFICATION_COOLDOWN_MS) {
+      recentNotifications.delete(key)
+    }
+  }
+
+  while (recentNotifications.size > MAX_RECENT_NOTIFICATION_KEYS) {
+    const oldest = recentNotifications.keys().next()
+    if (oldest.done) {
+      break
+    }
+    recentNotifications.delete(oldest.value)
+  }
+}
+
 export function registerNotificationHandlers(store: Store, runtime?: OrcaRuntimeService): void {
   const recentNotifications = new Map<string, number>()
 
@@ -245,16 +266,12 @@ export function registerNotificationHandlers(store: Store, runtime?: OrcaRuntime
         if (now - lastSentAt < NOTIFICATION_COOLDOWN_MS) {
           return { delivered: false, reason: 'cooldown' }
         }
+        recentNotifications.delete(dedupeKey)
         recentNotifications.set(dedupeKey, now)
 
-        // Evict stale entries so the map doesn't grow unbounded.
-        if (recentNotifications.size > 50) {
-          for (const [key, ts] of recentNotifications) {
-            if (now - ts >= NOTIFICATION_COOLDOWN_MS) {
-              recentNotifications.delete(key)
-            }
-          }
-        }
+        // Why: a storm across many worktrees should not make every
+        // notification dispatch scan an ever-growing cooldown table.
+        pruneRecentNotifications(recentNotifications, now)
       }
 
       const notificationOptions = buildNotificationOptions(args)