perf(theme): optimize the startup time of auto-frontmatter

theme/src/node/autoFrontmatter/baseFrontmatter.ts

@@ -0,0 +1,21 @@
+import { format } from 'date-fns'
+import type {
+  AutoFrontmatter,
+  AutoFrontmatterObject,
+} from '../../shared/index.js'
+
+export function createBaseFrontmatter(options: AutoFrontmatter): AutoFrontmatterObject {
+  const res: AutoFrontmatterObject = {}
+
+  if (options.createTime !== false) {
+    res.createTime = (formatTime: string, { createTime }, data) => {
+      if (formatTime)
+        return formatTime
+      if (data.friends || data.pageLayout === 'friends')
+        return
+      return format(new Date(createTime), 'yyyy/MM/dd HH:mm:ss')
+    }
+  }
+
+  return res
+}

theme/src/node/autoFrontmatter/generator.ts

@@ -3,7 +3,7 @@ import chokidar from 'chokidar'
 import { createFilter } from 'create-filter'
 import grayMatter from 'gray-matter'
 import jsonToYaml from 'json2yaml'
-import { fs, hash } from 'vuepress/utils'
+import { fs, hash, path } from 'vuepress/utils'
 import type { App } from 'vuepress'
 import { getThemeConfig } from '../loadConfig/index.js'
 import { readMarkdown, readMarkdownList } from './readFile.js'
@@ -16,6 +16,8 @@ import type {
   PlumeThemeLocaleOptions,
 } from '../../shared/index.js'
 
+const CACHE_FILE = 'markdown/auto-frontmatter.json'
+
 export interface Generate {
   globFilter: (id?: string) => boolean
   global: AutoFrontmatterObject
@@ -24,6 +26,9 @@ export interface Generate {
     filter: (id?: string) => boolean
     frontmatter: AutoFrontmatterObject
   }[]
+  cache: Record<string, string>
+  checkCache: (id: string) => boolean
+  updateCache: (app: App) => Promise<void>
 }
 
 let generate: Generate | null = null
@@ -53,21 +58,46 @@ export function initAutoFrontmatter(
       }
     })
 
+  const cache: Record<string, string> = {}
+
+  function checkCache(filepath: string): boolean {
+    const stats = fs.statSync(filepath)
+
+    if (cache[filepath] && cache[filepath] === stats.mtimeMs.toString())
+      return false
+    cache[filepath] = stats.mtimeMs.toString()
+    return true
+  }
+
+  async function updateCache(app: App): Promise<void> {
+    await fs.writeFile(app.dir.cache(CACHE_FILE), JSON.stringify(cache), 'utf-8')
+  }
+
   generate = {
     globFilter,
     global: globalConfig,
     rules,
+    cache,
+    checkCache,
+    updateCache,
   }
 }
 
 export async function generateAutoFrontmatter(app: App) {
   if (!generate)
     return
-  const markdownList = await readMarkdownList(app.dir.source(), generate.globFilter)
+
+  const cachePath = app.dir.cache(CACHE_FILE)
+  if (fs.existsSync(cachePath)) {
+    generate.cache = JSON.parse(await fs.readFile(cachePath, 'utf-8'))
+  }
+  const markdownList = await readMarkdownList(app, generate)
   await promiseParallel(
     markdownList.map(file => () => generator(file)),
     64,
   )
+
+  await generate.updateCache(app)
 }
 
 export async function watchAutoFrontmatter(app: App, watchers: any[]) {
@@ -88,6 +118,14 @@ export async function watchAutoFrontmatter(app: App, watchers: any[]) {
     await generator(file)
   })
 
+  watcher.on('change', async (relativePath) => {
+    const enabled = getThemeConfig().autoFrontmatter !== false
+    if (!generate!.globFilter(relativePath) || !enabled)
+      return
+    if (generate!.checkCache(path.join(app.dir.source(), relativePath)))
+      await generate!.updateCache(app)
+  })
+
   watchers.push(watcher)
 }
 
@@ -103,8 +141,11 @@ async function generator(file: AutoFrontmatterMarkdownFile): Promise<void> {
   const beforeHash = hash(data)
 
   for (const key in formatter) {
-    const value = await formatter[key](data[key], file, data)
-    data[key] = value ?? data[key]
+    const value = (await formatter[key](data[key], file, data)) ?? data[key]
+    if (typeof value !== 'undefined')
+      data[key] = value
+    else
+      delete data[key]
   }
 
   if (beforeHash === hash(data))
@@ -121,6 +162,7 @@ async function generator(file: AutoFrontmatterMarkdownFile): Promise<void> {
     const newContent = yaml ? `${yaml}---\n${content}` : content
 
     await fs.promises.writeFile(filepath, newContent, 'utf-8')
+    generate.checkCache(filepath)
   }
   catch (e) {
     console.error(e)

theme/src/node/autoFrontmatter/readFile.ts

@@ -1,20 +1,27 @@
 import fg from 'fast-glob'
 import { fs, path } from 'vuepress/utils'
+import type { App } from 'vuepress'
 import type { AutoFrontmatterMarkdownFile } from '../../shared/index.js'
+import type { Generate } from './generator.js'
 
 export async function readMarkdownList(
-  sourceDir: string,
-  filter: (id: string) => boolean,
+  app: App,
+  { globFilter, checkCache }: Generate,
 ): Promise<AutoFrontmatterMarkdownFile[]> {
+  const source = app.dir.source()
   const files: string[] = await fg(['**/*.md'], {
-    cwd: sourceDir,
+    cwd: source,
     ignore: ['node_modules', '.vuepress'],
   })
 
   return await Promise.all(
     files
-      .filter(filter)
-      .map(file => readMarkdown(sourceDir, file)),
+      .filter((id) => {
+        if (!globFilter(id))
+          return false
+        return checkCache(path.join(source, id))
+      })
+      .map(file => readMarkdown(source, file)),
   )
 }
 

theme/src/node/autoFrontmatter/resolveLinkBySidebar.ts

@@ -0,0 +1,51 @@
+import { pathJoin } from '../utils/index.js'
+import type { SidebarItem } from '../../shared/index.js'
+
+export function resolveLinkBySidebar(
+  sidebar: 'auto' | (string | SidebarItem)[],
+  _prefix: string,
+) {
+  const res: Record<string, string> = {}
+
+  if (sidebar === 'auto') {
+    return res
+  }
+
+  for (const item of sidebar) {
+    if (typeof item !== 'string') {
+      const { prefix, dir = '', link = '/', items, text = '' } = item
+      getSidebarLink(items, link, text, pathJoin(_prefix, prefix || dir), res)
+    }
+  }
+  return res
+}
+
+function getSidebarLink(items: 'auto' | (string | SidebarItem)[] | undefined, link: string, text: string, dir = '', res: Record<string, string> = {}) {
+  if (items === 'auto')
+    return
+
+  if (!items) {
+    res[pathJoin(dir, `${text}.md`)] = link
+    return
+  }
+
+  for (const item of items) {
+    if (typeof item === 'string') {
+      if (!link)
+        continue
+      if (item) {
+        res[pathJoin(dir, `${item}.md`)] = link
+      }
+      else {
+        res[pathJoin(dir, 'README.md')] = link
+        res[pathJoin(dir, 'index.md')] = link
+        res[pathJoin(dir, 'readme.md')] = link
+      }
+      res[dir] = link
+    }
+    else {
+      const { prefix, dir: subDir = '', link: subLink = '/', items: subItems, text: subText = '' } = item
+      getSidebarLink(subItems, pathJoin(link, subLink), subText, pathJoin(prefix || dir, subDir), res)
+    }
+  }
+}