perf(renderer): index terminal unified tab reads (#8076)

src/renderer/src/components/terminal-pane/TerminalPane.tsx

@@ -180,7 +180,10 @@ import {
   subscribeTerminalPaneAttention
 } from './terminal-pane-attention-subscriptions'
 import { getCachedTerminalTabForWorktree } from './terminal-tab-lookup'
-import { getCachedTerminalGroupIdForWorktree } from './terminal-unified-tab-lookup'
+import {
+  getCachedTerminalGroupIdForWorktree,
+  getCachedUnifiedTerminalTabForWorktree
+} from './terminal-unified-tab-lookup'
 import { resolveNativeChatLeafTitleAgent } from './native-chat-leaf-title-agent'
 import { useRepoById } from '@/store/selectors'
 import {
@@ -655,23 +658,18 @@ export default function TerminalPane({
   // communicates the presence-lock inside the chat surface instead (U9/R8).
   const unifiedTabId = useAppStore(
     (store) =>
-      (store.unifiedTabsByWorktree[worktreeId] ?? []).find(
-        (t) => t.contentType === 'terminal' && t.entityId === tabId
-      )?.id
+      getCachedUnifiedTerminalTabForWorktree(store.unifiedTabsByWorktree, worktreeId, tabId)?.id
   )
   const isChatViewMode = useAppStore(
     (store) =>
-      (store.unifiedTabsByWorktree[worktreeId] ?? []).find(
-        (t) => t.contentType === 'terminal' && t.entityId === tabId
-      )?.viewMode === 'chat'
+      getCachedUnifiedTerminalTabForWorktree(store.unifiedTabsByWorktree, worktreeId, tabId)
+        ?.viewMode === 'chat'
   )
   const nativeChatEnabled = useAppStore((store) => store.settings?.experimentalNativeChat === true)
   const effectiveChatViewMode = nativeChatEnabled && isChatViewMode
   const unifiedTabLabel = useAppStore(
     (store) =>
-      (store.unifiedTabsByWorktree[worktreeId] ?? []).find(
-        (t) => t.contentType === 'terminal' && t.entityId === tabId
-      )?.label
+      getCachedUnifiedTerminalTabForWorktree(store.unifiedTabsByWorktree, worktreeId, tabId)?.label
   )
   const runtimePaneTitlesByPaneId = useAppStore(
     useShallow((store) => store.runtimePaneTitlesByTabId[tabId] ?? {})

src/renderer/src/components/terminal-pane/terminal-unified-tab-lookup.test.ts

@@ -1,6 +1,9 @@
 import { describe, expect, it, vi } from 'vitest'
 import type { Tab } from '../../../../shared/types'
-import { getCachedTerminalGroupIdForWorktree } from './terminal-unified-tab-lookup'
+import {
+  getCachedTerminalGroupIdForWorktree,
+  getCachedUnifiedTerminalTabForWorktree
+} from './terminal-unified-tab-lookup'
 
 function makeTerminalTab(entityId: string, groupId: string): Tab {
   return {
@@ -45,8 +48,8 @@ function iterableTabs(tabs: Tab[]): {
   }
 }
 
-describe('getCachedTerminalGroupIdForWorktree', () => {
-  it('reuses the terminal group lookup while the unified tab array is unchanged', () => {
+describe('terminal unified tab lookup', () => {
+  it('shares one terminal lookup across all pane field and group reads', () => {
     const tabs = [
       makeEditorTab('editor-1'),
       ...Array.from({ length: 200 }, (_, index) =>
@@ -56,14 +59,23 @@ describe('getCachedTerminalGroupIdForWorktree', () => {
     const { value, iterator } = iterableTabs(tabs)
     const unifiedTabsByWorktree = { 'wt-1': value }
 
-    expect(getCachedTerminalGroupIdForWorktree(unifiedTabsByWorktree, 'wt-1', 'terminal-199')).toBe(
-      'group-3'
-    )
+    for (let index = 0; index < 200; index += 1) {
+      const terminalTabId = `terminal-${index}`
+      expect(
+        getCachedUnifiedTerminalTabForWorktree(unifiedTabsByWorktree, 'wt-1', terminalTabId)
+      ).toBe(tabs[index + 1])
+      expect(
+        getCachedUnifiedTerminalTabForWorktree(unifiedTabsByWorktree, 'wt-1', terminalTabId)?.id
+      ).toBe(terminalTabId)
+      expect(
+        getCachedUnifiedTerminalTabForWorktree(unifiedTabsByWorktree, 'wt-1', terminalTabId)?.label
+      ).toBe(terminalTabId)
+    }
     expect(getCachedTerminalGroupIdForWorktree(unifiedTabsByWorktree, 'wt-1', 'terminal-0')).toBe(
       'group-0'
     )
     expect(
-      getCachedTerminalGroupIdForWorktree(unifiedTabsByWorktree, 'wt-1', 'editor-1')
+      getCachedUnifiedTerminalTabForWorktree(unifiedTabsByWorktree, 'wt-1', 'editor-1')
     ).toBeNull()
 
     expect(iterator).toHaveBeenCalledTimes(1)
@@ -73,9 +85,9 @@ describe('getCachedTerminalGroupIdForWorktree', () => {
     const first = iterableTabs([makeTerminalTab('terminal-1', 'group-a')])
     const second = iterableTabs([makeTerminalTab('terminal-1', 'group-b')])
 
-    expect(getCachedTerminalGroupIdForWorktree({ 'wt-1': first.value }, 'wt-1', 'terminal-1')).toBe(
-      'group-a'
-    )
+    expect(
+      getCachedUnifiedTerminalTabForWorktree({ 'wt-1': first.value }, 'wt-1', 'terminal-1')?.groupId
+    ).toBe('group-a')
     expect(
       getCachedTerminalGroupIdForWorktree({ 'wt-1': second.value }, 'wt-1', 'terminal-1')
     ).toBe('group-b')

src/renderer/src/components/terminal-pane/terminal-unified-tab-lookup.ts

@@ -1,29 +1,40 @@
 import type { Tab } from '../../../../shared/types'
 
-const terminalGroupLookupByUnifiedTabs = new WeakMap<readonly Tab[], Map<string, string>>()
+const terminalTabLookupByUnifiedTabs = new WeakMap<readonly Tab[], Map<string, Tab>>()
+
+export function getCachedUnifiedTerminalTabForWorktree(
+  unifiedTabsByWorktree: Record<string, Tab[]>,
+  worktreeId: string,
+  terminalTabId: string
+): Tab | null {
+  const unifiedTabs = unifiedTabsByWorktree[worktreeId]
+  if (!unifiedTabs) {
+    return null
+  }
+
+  let lookup = terminalTabLookupByUnifiedTabs.get(unifiedTabs)
+  if (!lookup) {
+    // Why: every retained TerminalPane reads this tab on every store update.
+    // Share one immutable-array index instead of repeating linear scans.
+    lookup = new Map()
+    for (const tab of unifiedTabs) {
+      if (tab.contentType === 'terminal') {
+        lookup.set(tab.entityId, tab)
+      }
+    }
+    terminalTabLookupByUnifiedTabs.set(unifiedTabs, lookup)
+  }
+
+  return lookup.get(terminalTabId) ?? null
+}
 
 export function getCachedTerminalGroupIdForWorktree(
   unifiedTabsByWorktree: Record<string, Tab[]>,
   worktreeId: string,
   terminalTabId: string
 ): string | null {
-  const unifiedTabs = unifiedTabsByWorktree[worktreeId]
-  if (!unifiedTabs) {
-    return null
-  }
-
-  let lookup = terminalGroupLookupByUnifiedTabs.get(unifiedTabs)
-  if (!lookup) {
-    // Why: every mounted TerminalPane asks for its owning group on store updates.
-    // Cache by immutable tab-array ref so 200 panes do not repeat the same scan.
-    lookup = new Map()
-    for (const tab of unifiedTabs) {
-      if (tab.contentType === 'terminal') {
-        lookup.set(tab.entityId, tab.groupId)
-      }
-    }
-    terminalGroupLookupByUnifiedTabs.set(unifiedTabs, lookup)
-  }
-
-  return lookup.get(terminalTabId) ?? null
+  return (
+    getCachedUnifiedTerminalTabForWorktree(unifiedTabsByWorktree, worktreeId, terminalTabId)
+      ?.groupId ?? null
+  )
 }