⚡ perf(vscode): 预览切走标签页时页面留着，切回来不再重新生成、重发文档和整份重画

vscode/src/codeReader/callTree/session.ts

@@ -2,7 +2,7 @@
  * 文档发出去之后，在后台数每个能看调用树的块（函数、类、接口卡片）落在几棵调用树里，问到的都记下（没人调用的也记），数完把棵数发给页面。
  * 页面点开某一块时，问到过有调用者就把树发回去；没问过、或上回没人调用就当场问这一块，问到了补发棵数再发树，没问到发一棵空的；
  * 接口在契约文件里没对上时，发出去的树带着 contractMiss，页面照它说明，不当成没人调用。
- * 问到的结果跟着文档版本走：同一版文档又发一遍（标签页切回来页面重新加载、按新规则重发）时接着用，已知的棵数马上补发，
+ * 问到的结果跟着文档版本走：同一版文档又发一遍（页面重新加载、按新规则重发）时接着用，已知的棵数马上补发，
  * 只问还没问过（或问法变了）的块；换了一版、预览关掉才丢掉。问的时候文档版本变了，结果也丢掉。
  */
 

vscode/src/codeReader/editor/occurrenceNavigation.ts

@@ -7,7 +7,7 @@ export const OCCURRENCES_CONTEXT = 'superpowers.codeReader.hasOccurrences'
 
 /**
  * 上下文键跟着各预览报来的状态走：有一个预览能跳就是真（同一时刻只有一个页面有焦点），变了才设。
- * 预览关掉、页面被销毁（标签页切走）时当它不能跳。
+ * 预览关掉时当它不能跳；标签页切走时页面失了焦点，自己会报不能跳。
  */
 export class NavigationContext<Owner> {
   private readonly available = new Set<Owner>()

vscode/src/codeReader/editor/previewEditor.test.ts

@@ -6,16 +6,17 @@ import type { SymbolNode } from '../symbolLinks'
 import type { CodeColors } from '../theme/codeColors'
 import type { ExtensionToWebview, WebviewToExtension } from './messages'
 import { describe, expect, it, vi } from 'vitest'
-import { window, workspace } from 'vscode'
+import { commands, window, workspace } from 'vscode'
 import { documentMessage } from './documentMessage'
 import { documentSymbolNodes } from './documentSymbols'
-import { PreviewEditorProvider } from './previewEditor'
+import { OCCURRENCES_CONTEXT } from './occurrenceNavigation'
+import { PREVIEW_VIEW_TYPE, PreviewEditorProvider } from './previewEditor'
 
 vi.mock('vscode', () => ({
   commands: { executeCommand: vi.fn() },
-  window: { showErrorMessage: vi.fn() },
+  window: { showErrorMessage: vi.fn(), registerCustomEditorProvider: vi.fn() },
   workspace: {
-    onDidChangeTextDocument: () => ({ dispose: () => {} }),
+    onDidChangeTextDocument: vi.fn(() => ({ dispose: () => {} })),
     onDidChangeConfiguration: () => ({ dispose: () => {} }),
     getConfiguration: () => ({ get: (_key: string, fallback: unknown) => fallback }),
     openTextDocument: vi.fn(),
@@ -214,10 +215,10 @@ function opening(profiles = { ask: profileSet(''), rewrite: profileSet('') }, co
   return { provider, document, diffBase }
 }
 
-/** 一个标签页：收发消息、切走（页面被销毁，切回来重新加载、再发 ready） */
+/** 一个标签页：收发消息；切走、切回来时页面留着，VS Code 只报一声可见性变了 */
 function tab() {
   let receive: ((message: WebviewToExtension) => Promise<void>) | undefined
-  let viewStateChanged: (() => void) | undefined
+  const viewStateListeners: (() => void)[] = []
   const post = vi.fn<(message: ExtensionToWebview) => void>()
   const panel = {
     active: true,
@@ -231,20 +232,22 @@ function tab() {
         return { dispose: () => {} }
       },
     },
-    onDidChangeViewState: (listener: typeof viewStateChanged) => {
+    onDidChangeViewState: (listener: () => void) => {
-      viewStateChanged = listener
+      viewStateListeners.push(listener)
       return { dispose: () => {} }
     },
     onDidDispose: () => ({ dispose: () => {} }),
   }
+  const setVisible = (visible: boolean): void => {
+    panel.visible = visible
+    panel.active = visible
+    viewStateListeners.forEach(listener => listener())
+  }
   return {
     panel: panel as unknown as Parameters<PreviewEditorProvider['resolveCustomTextEditor']>[1],
     send: (message: WebviewToExtension) => receive!(message),
-    hide: () => {
+    hide: () => setVisible(false),
-      panel.visible = false
+    show: () => setVisible(true),
-      viewStateChanged!()
-      panel.visible = true
-    },
     posted: () => post.mock.calls.map(([message]) => message),
     clear: () => post.mockClear(),
   }
@@ -284,7 +287,7 @@ describe('预览对比什么看这个标签页是从哪儿打开的', () => {
     expect(diffBase).not.toHaveBeenCalledWith(document.uri, 'uncommitted')
   })
 
-  it('开着的预览再从主栏点开就不比，再从「未提交的更改」点开又比；只切标签页不变', async () => {
+  it('开着的预览再从主栏点开就不比，再从「未提交的更改」点开又比；页面重新加载后按它记着的照旧比', async () => {
     const { provider, document } = opening()
     const page = tab()
     await provider.open(document.uri as never, { from: 'uncommitted' }, async () => provider.resolveCustomTextEditor(document as never, page.panel))
@@ -301,7 +304,6 @@ describe('预览对比什么看这个标签页是从哪儿打开的', () => {
     expect(page.posted()).toContainEqual({ type: 'openedFrom', from: 'uncommitted' })
     await vi.waitFor(() => expect(page.posted()).toContainEqual(comparedWithHead))
 
-    page.hide()
     page.clear()
     await page.send({ type: 'ready', openedFrom: 'uncommitted' })
     expect(page.posted()).toContainEqual({ type: 'openedFrom', from: 'uncommitted' })
@@ -336,6 +338,67 @@ describe('预览对比什么看这个标签页是从哪儿打开的', () => {
   })
 })
 
+describe('标签页切走时页面留着', () => {
+  it('注册时就让页面在标签页切走后留着', () => {
+    const { provider } = opening()
+    provider.register()
+    expect(window.registerCustomEditorProvider).toHaveBeenCalledWith(PREVIEW_VIEW_TYPE, provider, { webviewOptions: { retainContextWhenHidden: true } })
+  })
+
+  it('切走再切回来：不重新生成文档、什么都不重发，高亮照旧能用键盘跳', async () => {
+    const { provider, document } = opening()
+    const page = tab()
+    await provider.open(document.uri as never, { from: 'uncommitted' }, async () => provider.resolveCustomTextEditor(document as never, page.panel))
+    await page.send({ type: 'ready' })
+    await vi.waitFor(() => expect(page.posted()).toContainEqual(comparedWithHead))
+    await page.send({ type: 'occurrenceNavigation', available: true })
+
+    page.clear()
+    vi.mocked(documentMessage).mockClear()
+    vi.mocked(commands.executeCommand).mockClear()
+    page.hide()
+    page.show()
+    // 比连续输入合并重新解析的那一下（150ms）等得久
+    await new Promise(resolve => setTimeout(resolve, 200))
+    expect(documentMessage).not.toHaveBeenCalled()
+    expect(page.posted()).toEqual([])
+    expect(commands.executeCommand).not.toHaveBeenCalledWith('setContext', OCCURRENCES_CONTEXT, false)
+  })
+
+  it('切走期间文件在别处改了：照常把新的文档发给留着的页面', async () => {
+    const { provider, document } = opening()
+    const page = tab()
+    provider.resolveCustomTextEditor(document as never, page.panel)
+    await page.send({ type: 'ready' })
+
+    page.hide()
+    page.clear()
+    document.version = 2
+    const edited = vi.mocked(workspace.onDidChangeTextDocument).mock.calls.at(-1)![0]
+    edited({ document, contentChanges: [{ rangeOffset: 0, rangeLength: 0, text: '// ' }] } as never)
+    await vi.waitFor(() => expect(page.posted()).toContainEqual(expect.objectContaining({ type: 'document', version: 2 })))
+  })
+
+  it('页面真的重新加载了（webview 进程崩了重建、开发者重载）：再发 ready 时照旧整份发一遍', async () => {
+    const { provider, document } = opening()
+    const page = tab()
+    await provider.open(document.uri as never, { from: 'uncommitted' }, async () => provider.resolveCustomTextEditor(document as never, page.panel))
+    await page.send({ type: 'ready' })
+    await vi.waitFor(() => expect(page.posted()).toContainEqual(comparedWithHead))
+
+    page.clear()
+    vi.mocked(documentMessage).mockClear()
+    await page.send({ type: 'ready', openedFrom: 'uncommitted' })
+    expect(documentMessage).toHaveBeenCalled()
+    expect(page.posted().map(message => message.type)).toEqual(expect.arrayContaining(['openedFrom', 'filter', 'qa', 'codeColors', 'document']))
+    await vi.waitFor(() => {
+      expect(page.posted()).toContainEqual(comparedWithHead)
+      expect(page.posted()).toContainEqual(expect.objectContaining({ type: 'profiles', kind: 'ask' }))
+      expect(page.posted()).toContainEqual(expect.objectContaining({ type: 'profiles', kind: 'rewrite' }))
+    })
+  })
+})
+
 describe('代码配色跟着当前颜色主题', () => {
   it('ready 后先于第一份文档发；换了主题发给 ready 了的预览，还没 ready 的等 ready 时发眼下的', async () => {
     const colors = themeColors(COLORS)

vscode/src/codeReader/editor/previewEditor.ts

@@ -103,6 +103,14 @@ export class PreviewEditorProvider implements CustomTextEditorProvider {
     readonly askFeature: (subject: Uri, request: TopRequest) => Promise<string | undefined>,
   ) {}
 
+  /**
+   * 注册成预览编辑器。标签页切走时页面留着（`retainContextWhenHidden`）：切回来不用重新生成、重发文档，页面也不用整份重画，
+   * 代价是每个开着的预览切走后仍占着它那个页面的内存。
+   */
+  register(): Disposable {
+    return window.registerCustomEditorProvider(PREVIEW_VIEW_TYPE, this, { webviewOptions: { retainContextWhenHidden: true } })
+  }
+
   /**
    * 用 `show` 打开 `uri` 的预览，把 `request` 交给它：新建的预览解析时带走；`show` 只是切到了已经开着的预览（没有新建）时，交给切到的那个。
    *
@@ -174,7 +182,10 @@ export class PreviewEditorProvider implements CustomTextEditorProvider {
 }
 
 class Preview {
-  /** webview 发过 ready 之后才发消息；标签页切走时页面被销毁，切回来重新加载、再发 ready，这期间也不发 */
+  /**
+   * 页面发过 ready（装好了、能收消息）之后才发消息。标签页切走时页面留着，照常收消息，切回来什么都不用补；
+   * 页面真的重新加载了（webview 进程崩了重建、开发者重载 webview）会再发 ready，那时整份重发
+   */
   private ready = false
   /** 侧栏「问 AI」打开的：页面准备好后把光标放进顶部输入框 */
   private pendingPathFocus = false
@@ -215,8 +226,8 @@ class Preview {
   /** 这份文件相比对比基准改了什么：发完文档再算、补发 */
   private readonly diff: PreviewDiff
   /**
-   * 随下一份真正发出去的文档走、只走一次：新预览第一份文档要滚到的位置，或页面正在重新加载时收不到的 reveal。
+   * 随下一份真正发出去的文档走、只走一次：新预览第一份文档要滚到的位置，或页面 ready 之前又来的 reveal。
-   * 之后页面因标签页切走重新加载，按 webview 自己记的位置恢复
+   * 之后页面真的重新加载了，按 webview 自己记的位置恢复
    */
   private pendingReveal: Reveal | undefined
   /** 这个标签页是从哪儿打开的，定对比什么；打开请求没说的（跳定义新开的、VS Code 重启后恢复的）先空着，页面 ready 时按它记着的定 */
@@ -243,7 +254,7 @@ class Preview {
       },
     })
     this.names = new DocumentNames((version, names) => {
-      if (this.ready && version === document.version)
+      if (version === document.version)
         this.post({ type: 'displayNames', version, names })
     })
     this.lookups = new DocumentLookups(() => this.schedulePush())
@@ -251,25 +262,15 @@ class Preview {
     this.diff = new PreviewDiff(
       () => this.from === undefined ? undefined : owner.diffBases.diffBase(document.uri, this.from),
       source => this.readOld(source),
-      (diff) => {
+      diff => this.post({ type: 'diff', diff }),
-        if (this.ready)
-          this.post({ type: 'diff', diff })
-      },
       text => logger.add({ level: 'warn', source: 'codeReader', message: `${document.uri.fsPath}：${text}` }),
     )
     this.disposables = [
       owner.diffBases.onDidChange(() => {
-        if (this.ready && this.sent)
+        if (this.sent)
           void this.diff.update(this.sent)
       }),
       panel.webview.onDidReceiveMessage((msg: WebviewToExtension) => this.handleMessage(msg)),
-      panel.onDidChangeViewState(() => {
-        if (panel.visible)
-          return
-        // 页面被销毁了，高亮跟着没了
-        this.ready = false
-        owner.navigation.update(this, false)
-      }),
       workspace.onDidChangeTextDocument((e) => {
         if (e.document !== document || e.contentChanges.length === 0)
           return
@@ -391,7 +392,7 @@ class Preview {
     const { message, displayNames, symbols, imports } = await documentMessage({ languageId, version, getText: () => source, fileName: this.document.fileName, entryNames: this.owner.entries.namesOf(this.document.uri) }, this.registry, this.runtime, (text) => {
       logger.add({ level: 'warn', source: 'codeReader', message: `${this.document.uri.fsPath}：${text}` })
     }, session.lookup, callees.calleeKind)
-    if (request !== this.latest || !this.ready)
+    if (request !== this.latest)
       return
     this.definitions.remember(message.version, message.blocks)
     // 解析失败的文档没有块：问 AI 找不到块，也不拿它比差异
@@ -490,7 +491,7 @@ class Preview {
     }
   }
 
-  /** 跳到高亮着的名字的下一处 / 上一处出现；页面不在就算了（页面重新加载时高亮已经没了）。 */
+  /** 跳到高亮着的名字的下一处 / 上一处出现；页面还没 ready 就算了（还没有高亮）。 */
   moveOccurrence(step: 1 | -1): void {
     if (this.ready)
       this.post({ type: 'moveOccurrence', step })
@@ -512,7 +513,7 @@ class Preview {
       this.focusPathAsk()
   }
 
-  /** 滚到 reveal：页面在就直接发，正在重新加载就等它发 ready 后随文档带过去。 */
+  /** 滚到 reveal：页面 ready 了就直接发，还没 ready 就等它发 ready 后随文档带过去。 */
   private reveal(reveal: Reveal): void {
     if (this.ready)
       this.post({ type: 'reveal', ...reveal })
@@ -556,10 +557,9 @@ class Preview {
     this.post({ type: 'focusPathAsk' })
   }
 
-  /** kind 那种对话的 profile 列表每次现读（同看板），读完页面还在才发。 */
+  /** kind 那种对话的 profile 列表每次现读（同看板）。 */
   private async postProfiles(kind: ChatKind): Promise<void> {
     const choice = await this.owner.qa.profiles[kind].choice()
-    if (this.ready)
     this.post({ type: 'profiles', kind, ...choice })
   }
 
@@ -602,6 +602,7 @@ class Preview {
   private async handleMessage(msg: WebviewToExtension): Promise<void> {
     switch (msg.type) {
       case 'ready':
+        // 页面刚装好（新开的、VS Code 重启后恢复的、真的重新加载了的）：眼下的状态和文档整份发一遍
         this.ready = true
         // 打开请求说了从哪儿打开的就按它；没说的按页面记着的（VS Code 重启后恢复的），页面也没记过的（新开的）不比
         this.from ??= msg.openedFrom ?? 'other'
@@ -709,7 +710,7 @@ class Preview {
     if (version !== document.version)
       return
     const occurrences = await this.occurrences(offset)
-    if (version === document.version && this.ready)
+    if (version === document.version)
       this.post({ type: 'occurrencesFound', id, occurrences })
   }
 
@@ -719,7 +720,7 @@ class Preview {
     if (version !== document.version)
       return
     const found = (await this.definitions.locate(version, offset)).length > 0
-    if (version === document.version && this.ready)
+    if (version === document.version)
       this.post({ type: 'definitionProbed', id, found })
   }
 
@@ -774,7 +775,7 @@ class Preview {
     const [definition] = await findDefinitions(await this.definitions.locate(version, offset))
     const own = definition?.uri === document.uri.toString() && definition.offset === offset
     const peek = definition && !own ? await this.peekAt(definition.location.uri, definition.offset) : undefined
-    if (version === document.version && this.ready)
+    if (version === document.version)
       this.post({ type: 'definitionPeeked', id, ...(peek && { peek }) })
   }
 
@@ -789,7 +790,6 @@ class Preview {
       const link = rel === undefined ? `[${symbol}]` : `${rel}#${symbol}`
       logger.add({ level: 'warn', source: 'codeReader', message: `没能找 ${link} 指的符号：${err instanceof Error ? err.message : String(err)}` })
     }
-    if (this.ready)
     this.post({ type: 'definitionPeeked', id, ...(peek && { peek }) })
   }
 
@@ -869,7 +869,6 @@ class Preview {
       })),
       Promise.all(references.map(async reference => await this.resolveSymbolLink(reference, symbolsOf) ? undefined : reference)),
     ])
-    if (this.ready)
     this.post({ type: 'repoLinksChecked', id, missing: missing.filter(rel => rel !== undefined), unresolved: unresolved.filter(reference => reference !== undefined) })
   }
 
@@ -908,7 +907,6 @@ class Preview {
       const src = this.panel.webview.asWebviewUri(Uri.file(entry.fsPath)).toString()
       return { path: rel, src }
     }))
-    if (this.ready)
     this.post({ type: 'repoImagesChecked', id, images })
   }
 
@@ -1010,12 +1008,10 @@ class Preview {
   }
 
   private markRepoLinkBroken(path: string | undefined, symbol?: string, block?: string): void {
-    if (this.ready)
     this.post({ type: 'repoLinkBroken', ...(path !== undefined && { path }), ...(symbol !== undefined && { symbol }), ...(block !== undefined && { block }) })
   }
 
   private markRepoLinkOpened(path: string | undefined, symbol?: string, block?: string): void {
-    if (this.ready)
     this.post({ type: 'repoLinkOpened', ...(path !== undefined && { path }), ...(symbol !== undefined && { symbol }), ...(block !== undefined && { block }) })
   }
 

vscode/src/codeReader/index.ts

@@ -15,7 +15,7 @@ import { BlockFilter } from './editor/blockFilter'
 import { NEXT_OCCURRENCE, PREVIOUS_OCCURRENCE } from './editor/occurrenceNavigation'
 import { languageOf, openingFor } from './editor/openTarget'
 import { PATH_PREVIEW_SCHEME } from './editor/pathPreview'
-import { PREVIEW_VIEW_TYPE, PreviewEditorProvider } from './editor/previewEditor'
+import { PreviewEditorProvider } from './editor/previewEditor'
 import { EditorSwitch } from './editor/switchEditor'
 import { WorkspaceEntries } from './entries/workspaceEntries'
 import { registerCopyCommands } from './explorer/copyCommands'
@@ -168,7 +168,7 @@ export function registerCodeReader(context: ExtensionContext): CodeReaderApi {
       void commands.executeCommand('setContext', LANGUAGE_IDS_CONTEXT, registry.languageIds())
       previews.refresh()
     }),
-    window.registerCustomEditorProvider(PREVIEW_VIEW_TYPE, previews),
+    previews.register(),
     files,
     view,
     locator,

vscode/webview-ui/src/codeReader/App.test.tsx

@@ -9,7 +9,7 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import { App } from './App'
 import { createViewStateStore } from './viewState'
 
-/** 扩展端那头：页面发出去的消息、页面挂着的收消息回调，以及 webview 自己存的状态（标签页切回来页面重新加载时还在） */
+/** 扩展端那头：页面发出去的消息、页面挂着的收消息回调，以及 webview 自己存的状态（页面重新加载时还在） */
 const host = vi.hoisted(() => ({
   posted: [] as unknown[],
   listeners: new Set<(msg: unknown) => void>(),
@@ -99,7 +99,7 @@ afterEach(async () => {
   vi.unstubAllGlobals()
 })
 
-describe('标签页切走再切回来，调用树弹框照旧开着', () => {
+describe('页面重新加载后，调用树弹框照旧开着', () => {
   it('弹框开着、选了第二个入口：页面重新加载拿到文档后重新打开那块、要它的树，停回第二个入口；关掉后再加载就不开了', async () => {
     await load()
     await deliver(documentOf(3, [block('0', 'mask_phone')]))
@@ -127,7 +127,7 @@ describe('标签页切走再切回来，调用树弹框照旧开着', () => {
     expect(host.posted).not.toContainEqual(expect.objectContaining({ type: 'openCallTree' }))
   })
 
-  it('页面重新加载前切走、文档还没到又切走一次，记着的弹框还在', async () => {
+  it('重新加载后文档还没到，页面又重新加载了一次：记着的弹框还在', async () => {
     saved = { editing: [], folds: {}, callTree: { anchor: 'mask_phone', entry: 1 } }
     await load()
     await unload()

vscode/webview-ui/src/codeReader/useScrollPosition.ts

@@ -50,7 +50,7 @@ function record(reportedLine: { current: number | undefined }): void {
 
 /**
  * 记住并恢复预览看到的位置：
- * ① 滚动时把视口顶部那块记进 webview 状态，页面因标签页切走被重新加载后照着滚回去；
+ * ① 滚动时把视口顶部那块记进 webview 状态，页面重新加载后（VS Code 重启后恢复标签页、webview 进程崩了重建）照着滚回去；
  * ② 同时把那块的起始行报给扩展端，切回文本编辑器时把这行放到顶部。
  * 第一份文档带 reveal（刚从文本编辑器切过来、跳到定义）时不恢复，交给 useReveal 滚。
  */

vscode/webview-ui/src/codeReader/viewState.ts

@@ -2,7 +2,7 @@ import type { ScrollAnchor } from './scrollPosition'
 import type { BlockView, OpenedFrom } from './types'
 
 /**
- * 标签页切走时 VS Code 会销毁 webview、切回来重新加载，靠它恢复：哪些块停在「编辑」、
+ * 页面重新加载（webview 进程崩了重建、开发者重载 webview）时靠它恢复（标签页切走时页面一直留着，用不上它）：哪些块停在「编辑」、
  * 用户把哪些块、属性行和子行折叠 / 展开了（块 id 是它在树里的位置，文档刷新后照旧对得上；属性行、子行 id 见 [propertyRowId]、[propertyItemId]），滚到了哪，
  * 以及开着哪一块的调用树弹框、选中第几个入口。
  * VS Code 重启后恢复标签页时也带着它，这个标签页是从哪儿打开的靠它报回扩展端。