perf(renderer): dedupe concurrent Markdown document scans

src/renderer/src/components/editor/markdown-document-list-request.test.ts

@@ -0,0 +1,88 @@
+import { describe, expect, it, vi } from 'vitest'
+import type { MarkdownDocument } from '../../../../shared/types'
+import type { RuntimeFileOperationArgs } from '@/runtime/runtime-file-client'
+import {
+  getMarkdownDocumentListRequestKey,
+  requestSharedMarkdownDocumentList
+} from './markdown-document-list-request'
+
+function context(overrides: Partial<RuntimeFileOperationArgs> = {}): RuntimeFileOperationArgs {
+  return {
+    settings: { activeRuntimeEnvironmentId: null },
+    worktreeId: 'worktree-1',
+    worktreePath: '/repo',
+    ...overrides
+  }
+}
+
+function deferred<T>(): {
+  promise: Promise<T>
+  reject: (error: Error) => void
+  resolve: (value: T) => void
+} {
+  let resolve!: (value: T) => void
+  let reject!: (error: Error) => void
+  const promise = new Promise<T>((resolvePromise, rejectPromise) => {
+    resolve = resolvePromise
+    reject = rejectPromise
+  })
+  return { promise, reject, resolve }
+}
+
+describe('shared Markdown document list requests', () => {
+  it('collapses concurrent pane scans and releases the result after settlement', async () => {
+    const pending = deferred<MarkdownDocument[]>()
+    const load = vi.fn(() => pending.promise)
+    const requests = Array.from({ length: 200 }, () =>
+      requestSharedMarkdownDocumentList(context(), '/repo', load)
+    )
+
+    expect(load).toHaveBeenCalledTimes(1)
+    expect(new Set(requests).size).toBe(1)
+
+    const documents = [{ filePath: '/repo/README.md', relativePath: 'README.md' }]
+    pending.resolve(documents as MarkdownDocument[])
+    await expect(Promise.all(requests)).resolves.toEqual(
+      Array.from({ length: 200 }, () => documents)
+    )
+
+    const nextDocuments = [{ filePath: '/repo/notes.md', relativePath: 'notes.md' }]
+    load.mockResolvedValueOnce(nextDocuments as MarkdownDocument[])
+    await expect(requestSharedMarkdownDocumentList(context(), '/repo', load)).resolves.toBe(
+      nextDocuments
+    )
+    expect(load).toHaveBeenCalledTimes(2)
+  })
+
+  it('keeps runtime routes isolated and encodes unusual paths losslessly', () => {
+    const local = context()
+    const ssh = context({ connectionId: 'ssh-1' })
+    const runtime = context({ settings: { activeRuntimeEnvironmentId: ' runtime-1 ' } })
+    const unusualRoot = '/repo\nwith-newline'
+
+    expect(getMarkdownDocumentListRequestKey(local, unusualRoot)).not.toBe(
+      getMarkdownDocumentListRequestKey(ssh, unusualRoot)
+    )
+    expect(getMarkdownDocumentListRequestKey(ssh, unusualRoot)).not.toBe(
+      getMarkdownDocumentListRequestKey(runtime, unusualRoot)
+    )
+    expect(JSON.parse(getMarkdownDocumentListRequestKey(local, unusualRoot)).at(-1)).toBe(
+      unusualRoot
+    )
+  })
+
+  it('clears rejected requests so a retry can run', async () => {
+    const failure = deferred<MarkdownDocument[]>()
+    const load = vi.fn(() => failure.promise)
+    const first = requestSharedMarkdownDocumentList(context(), '/retry', load)
+    const second = requestSharedMarkdownDocumentList(context(), '/retry', load)
+
+    failure.reject(new Error('offline'))
+    await expect(first).rejects.toThrow('offline')
+    await expect(second).rejects.toThrow('offline')
+
+    load.mockResolvedValueOnce([])
+    await expect(requestSharedMarkdownDocumentList(context(), '/retry', load)).resolves.toEqual([])
+    expect(load).toHaveBeenCalledTimes(2)
+  })
+})

src/renderer/src/components/editor/markdown-document-list-request.ts

@@ -0,0 +1,47 @@
+import type { MarkdownDocument } from '../../../../shared/types'
+import {
+  listRuntimeMarkdownDocuments,
+  type RuntimeFileOperationArgs
+} from '@/runtime/runtime-file-client'
+
+type MarkdownDocumentListLoader = (
+  context: RuntimeFileOperationArgs,
+  rootPath: string
+) => Promise<MarkdownDocument[]>
+
+const inFlightMarkdownDocumentLists = new Map<string, Promise<MarkdownDocument[]>>()
+
+export function getMarkdownDocumentListRequestKey(
+  context: RuntimeFileOperationArgs,
+  rootPath: string
+): string {
+  return JSON.stringify([
+    context.settings?.activeRuntimeEnvironmentId?.trim() ?? '',
+    context.connectionId ?? '',
+    context.worktreeId ?? '',
+    context.worktreePath ?? '',
+    rootPath
+  ])
+}
+
+export function requestSharedMarkdownDocumentList(
+  context: RuntimeFileOperationArgs,
+  rootPath: string,
+  load: MarkdownDocumentListLoader = listRuntimeMarkdownDocuments
+): Promise<MarkdownDocument[]> {
+  const key = getMarkdownDocumentListRequestKey(context, rootPath)
+  const existing = inFlightMarkdownDocumentLists.get(key)
+  if (existing) {
+    return existing
+  }
+
+  // Why: split Markdown panes mount together and otherwise launch identical
+  // whole-worktree local/SSH scans; share only concurrent work so freshness is unchanged.
+  const request = load(context, rootPath).finally(() => {
+    if (inFlightMarkdownDocumentLists.get(key) === request) {
+      inFlightMarkdownDocumentLists.delete(key)
+    }
+  })
+  inFlightMarkdownDocumentLists.set(key, request)
+  return request
+}

src/renderer/src/components/editor/useMarkdownDocuments.ts

@@ -2,7 +2,7 @@ import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 import type { MarkdownDocument } from '../../../../shared/types'
 import { useAppStore } from '@/store'
 import { getConnectionId } from '@/lib/connection-context'
-import { listRuntimeMarkdownDocuments, statRuntimePath } from '@/runtime/runtime-file-client'
+import { statRuntimePath } from '@/runtime/runtime-file-client'
 import { settingsForRuntimeOwner } from '@/runtime/runtime-rpc-client'
 import type { MarkdownViewMode, OpenFile } from '@/store/slices/editor'
 import {
@@ -11,6 +11,7 @@ import {
   resolveMarkdownDocLink
 } from './markdown-doc-links'
 import { selectMarkdownDocumentWorktreePath } from './markdown-document-worktree-path-selector'
+import { requestSharedMarkdownDocumentList } from './markdown-document-list-request'
 
 type OpenMarkdownDocumentOptions = {
   anchor?: string | null
@@ -60,7 +61,7 @@ export function useMarkdownDocuments(
     const requestId = requestRef.current + 1
     requestRef.current = requestId
     try {
-      const documents = await listRuntimeMarkdownDocuments(
+      const documents = await requestSharedMarkdownDocumentList(
         {
           settings: settingsForRuntimeOwner(
             useAppStore.getState().settings,