From 8d07dab951edab6397d3f632a9c31f0eda2fd8a5 Mon Sep 17 00:00:00 2001
From: pengzhanbo <volodymyr@foxmail.com>
Date: Fri, 19 Jul 2024 11:57:35 +0800
Subject: [PATCH] perf(theme): optimize auto frontmatter `I/O`, #124

---
 theme/src/node/autoFrontmatter/generator.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/theme/src/node/autoFrontmatter/generator.ts b/theme/src/node/autoFrontmatter/generator.ts
index 06cf7039..57d1835e 100644
--- a/theme/src/node/autoFrontmatter/generator.ts
+++ b/theme/src/node/autoFrontmatter/generator.ts
@@ -1,4 +1,4 @@
-import { fs } from 'vuepress/utils'
+import { fs, hash } from 'vuepress/utils'
 import chokidar from 'chokidar'
 import { createFilter } from 'create-filter'
 import grayMatter from 'gray-matter'
@@ -99,11 +99,16 @@ async function generator(file: AutoFrontmatterMarkdownFile): Promise<void> {
   const formatter = current?.frontmatter || generate.global
   const { data, content } = grayMatter(file.content)
 
+  const beforeHash = hash(data)
+
   for (const key in formatter) {
     const value = await formatter[key](data[key], file, data)
     data[key] = value ?? data[key]
   }
 
+  if (beforeHash === hash(data))
+    return
+
   try {
     const yaml = isEmptyObject(data)
       ? ''