fix: Cache TOC for later usage in the case of cached file html (#649)

src/core/render/compiler.js

@@ -85,7 +85,10 @@ export class Compiler {
     }
 
     this._marked = compile
-    this.compile = cached(text => {
+    this.compile = text => {
+      let isCached = true
+      const result = cached(_ => {
+        isCached = false
         let html = ''
 
         if (!text) {
@@ -102,7 +105,18 @@ export class Compiler {
         slugify.clear()
 
         return html
-    })
+      })(text)
+
+      const curFileName = this.router.parse().file
+
+      if (isCached) {
+        this.toc = this.cacheTOC[curFileName]
+      } else {
+        this.cacheTOC[curFileName] = [...this.toc]
+      }
+
+      return result
+    }
   }
 
   compileEmbed(href, title) {