From 373b9c745cb5dfe25e942e720aca2cdac78e1874 Mon Sep 17 00:00:00 2001
From: segayuu <segayuu@gmail.com>
Date: Fri, 13 Apr 2018 23:23:48 +0900
Subject: [PATCH] Split cache in Post.prototype.render() into classes (#3117)

* Divide internal cache of Post.prototype.render into classes

* move RegExp object into local scope

* Combine unnecessarily divided callbacks in Post.prototype.render().

* refactor: Post.prototype.render()
---
 lib/hexo/post.js | 110 +++++++++++++++++++++++------------------------
 1 file changed, 55 insertions(+), 55 deletions(-)

diff --git a/lib/hexo/post.js b/lib/hexo/post.js
index 181faf8e39..5710908910 100644
--- a/lib/hexo/post.js
+++ b/lib/hexo/post.js
@@ -9,16 +9,40 @@ const { slugize, escapeRegExp } = require('hexo-util');
 const fs = require('hexo-fs');
 const yfm = require('hexo-front-matter');
 
-const rEscapeContent = /<escape(?:[^>]*)>([\s\S]*?)<\/escape>/g;
-const rSwigVar = /\{\{[\s\S]*?\}\}/g;
-const rSwigComment = /\{#[\s\S]*?#\}/g;
-const rSwigBlock = /\{%[\s\S]*?%\}/g;
-const rSwigFullBlock = /\{% *(.+?)(?: *| +.*)%\}[\s\S]+?\{% *end\1 *%\}/g;
-const placeholder = '\uFFFC';
-const rPlaceholder = /(?:<|&lt;)!--\uFFFC(\d+)--(?:>|&gt;)/g;
-
 const preservedKeys = ['title', 'slug', 'path', 'layout', 'date', 'content'];
 
+function PostRenderCache() {
+  this.cache = [];
+}
+
+const _escapeContent = (cache, str) => {
+  const placeholder = '\uFFFC';
+  return `<!--${placeholder}${cache.push(str) - 1}-->`;
+};
+
+PostRenderCache.prototype.escapeContent = function(str) {
+  const rEscapeContent = /<escape(?:[^>]*)>([\s\S]*?)<\/escape>/g;
+  return str.replace(rEscapeContent, (_, content) => _escapeContent(this.cache, content));
+};
+
+PostRenderCache.prototype.loadContent = function(str) {
+  const rPlaceholder = /(?:<|&lt;)!--\uFFFC(\d+)--(?:>|&gt;)/g;
+  return str.replace(rPlaceholder, (_, index) => this.cache[index]);
+};
+
+PostRenderCache.prototype.escapeAllSwigTags = function(str) {
+  const rSwigVar = /\{\{[\s\S]*?\}\}/g;
+  const rSwigComment = /\{#[\s\S]*?#\}/g;
+  const rSwigBlock = /\{%[\s\S]*?%\}/g;
+  const rSwigFullBlock = /\{% *(.+?)(?: *| +.*)%\}[\s\S]+?\{% *end\1 *%\}/g;
+
+  const escape = _str => _escapeContent(this.cache, _str);
+  return str.replace(rSwigFullBlock, escape)
+    .replace(rSwigBlock, escape)
+    .replace(rSwigComment, '')
+    .replace(rSwigVar, escape);
+};
+
 function Post(context) {
   this.context = context;
 }
@@ -200,36 +224,9 @@ Post.prototype.publish = function(data, replace, callback) {
 Post.prototype.render = function(source, data = {}, callback) {
   const ctx = this.context;
   const { config } = ctx;
-  const cache = [];
   const { tag } = ctx.extend;
   const ext = data.engine || (source ? pathFn.extname(source) : '');
 
-  const isSwig = ext === 'swig';
-
-  let disableNunjucks = false;
-
-  if (ext && ctx.render.renderer.get(ext)) {
-
-    // disable Nunjucks when the renderer spcify that.
-
-    disableNunjucks = disableNunjucks || !!ctx.render.renderer.get(ext).disableNunjucks;
-
-  }
-
-  function escapeContent(str) {
-    return `<!--${placeholder}${cache.push(str) - 1}-->`;
-  }
-
-  function tagFilter(content) {
-    if (disableNunjucks) return content;
-    // Replace cache data with real contents
-    content = content.replace(rPlaceholder, (...args) => cache[args[1]]);
-
-    // Render with Nunjucks
-    data.content = content;
-    return tag.render(data.content, data);
-  }
-
   let promise;
 
   if (data.content != null) {
@@ -241,24 +238,29 @@ Post.prototype.render = function(source, data = {}, callback) {
     return Promise.reject(new Error('No input file or string!')).asCallback(callback);
   }
 
+  const isSwig = ext === 'swig';
+
+  // disable Nunjucks when the renderer spcify that.
+  const disableNunjucks = ext && ctx.render.renderer.get(ext) && !!ctx.render.renderer.get(ext).disableNunjucks;
+
+  const cacheObj = new PostRenderCache();
+
   return promise.then(content => {
     data.content = content;
 
     // Run "before_post_render" filters
-    return ctx.execFilter('before_post_render', data, {context: ctx}).then(() => {
-      data.content = data.content.replace(rEscapeContent, (match, content) => escapeContent(content));
-    });
+    return ctx.execFilter('before_post_render', data, {context: ctx});
   }).then(() => {
-    // Skip rendering if this is a swig file
-    if (isSwig) return data.content;
+    data.content = cacheObj.escapeContent(data.content);
+
+    if (isSwig) {
+      // Render with Nunjucks if this is a swig file
+      return tag.render(data.content, data);
+    }
 
     // Escape all Swig tags
     if (!disableNunjucks) {
-      data.content = data.content
-        .replace(rSwigFullBlock, escapeContent)
-        .replace(rSwigBlock, escapeContent)
-        .replace(rSwigComment, '')
-        .replace(rSwigVar, escapeContent);
+      data.content = cacheObj.escapeAllSwigTags(data.content);
     }
 
     const options = data.markdown || {};
@@ -270,17 +272,15 @@ Post.prototype.render = function(source, data = {}, callback) {
       path: source,
       engine: data.engine,
       toString: true,
-      onRenderEnd: tagFilter
-    }, options);
-  }).then(content => {
-    data.content = content;
+      onRenderEnd(content) {
+        if (disableNunjucks) return content;
+        // Replace cache data with real contents
+        data.content = cacheObj.loadContent(content);
 
-    if (!isSwig) {
-      return data.content;
-    }
-
-    // Render with Nunjucks
-    return tag.render(data.content, data);
+        // Render with Nunjucks
+        return tag.render(data.content, data);
+      }
+    }, options);
   }).then(content => {
     data.content = content;