Caching of expensive templates during rendering (trending-tags)

[jakerr]

Rendering _includes/trending-tags.html for site with many tags / posts is quite slow.

Description

In an unmodified new repo from the chirpy template, as well as on a fresh checkout of main. Importing a blog with 330 posts including 750 tags the site build takes about 4 minutes timed with jekyll s --profile

Build Process Summary:

| PHASE    |     TIME |
+----------+----------+
| RESET    |   0.0001 |
| READ     |   3.2577 |
| GENERATE |   0.0311 |
| RENDER   | 238.4877 |
| CLEANUP  |   0.0143 |
| WRITE    |   0.1458 |

Site Render Stats:

| Filename                                                           | Count |      Bytes |    Time |
+--------------------------------------------------------------------+-------+------------+---------+
| _includes/trending-tags.html                                       |  2346 | 225841.45K | 227.050 |
| _layouts/page.html                                                 |  1173 | 122030.48K | 121.067 |
| _layouts/default.html                                              |  1173 | 252854.99K | 116.072 |
| _includes/search-results.html                                      |  1173 | 113272.39K | 113.785 |
| _includes/related-posts.html                                       |   327 |   3533.14K |   6.505 |
| _includes/head.html                                                |  1173 |   8299.20K |   1.181 |

...

To Reproduce

Create a new chirpy site from the template and place many posts that have tags into the _posts directory.

Desired behavior

It would be nice if templates that are known to produce the same output site-wide could somehow be cached while rendering.

I experimented with the jekyll-include-cache and saw good results.

By adding jekyll-include-cache as a plugin and then overriding the _layout & _includes files which reference trending-tags.html I was able to render the same site in ~11 seconds.

Build Process Summary:

| PHASE    |    TIME |
+----------+---------+
| RESET    |  0.0001 |
| READ     |  1.6198 |
| GENERATE |  0.0346 |
| RENDER   | 10.6490 |
| CLEANUP  |  0.0087 |
| WRITE    |  0.1347 |


Site Render Stats:

| Filename                                                           | Count |      Bytes |  Time |
+--------------------------------------------------------------------+-------+------------+-------+
| _layouts/page.html                                                 |  1172 | 121722.75K | 7.679 |
| jekyll-theme-chirpy-6.0.1/_includes/related-posts.html             |   327 |   3533.11K | 6.397 |
| _layouts/default.html                                              |  1172 | 248347.79K | 1.818 |
| jekyll-theme-chirpy-6.0.1/_includes/update-list.html               |  1172 |     72.11K | 0.897 |

...

The diff that produces this faster output

diff generated with this git command

git diff --no-index --diff-filter=M $(bundle info --path jekyll-theme-chirpy)/_layouts _layouts
git diff --no-index --diff-filter=M $(bundle info --path jekyll-theme-chirpy)/_includes _includes

diff --git a/Users/jakerr/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/jekyll-theme-chirpy-6.0.1/_layouts/page.html b/./_layouts/page.html
index 447977d..233ee18 100644
--- a/Users/jakerr/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/jekyll-theme-chirpy-6.0.1/_layouts/page.html
+++ b/./_layouts/page.html
@@ -45,7 +45,7 @@ layout: default
   <div id="panel-wrapper" class="col-xl-3 ps-2 text-muted">
     <div class="access">
       {% include update-list.html lang=lang %}
-      {% include trending-tags.html lang=lang %}
+      {% include_cached trending-tags.html lang=lang %}
     </div>
 
     {% for _include in layout.panel_includes %}

diff --git a/Users/jakerr/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/jekyll-theme-chirpy-6.0.1/_includes/search-results.html b/_includes/search-results.html
index e4ffb48..07981ff 100644
--- a/Users/jakerr/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/jekyll-theme-chirpy-6.0.1/_includes/search-results.html
+++ b/_includes/search-results.html
@@ -3,7 +3,7 @@
 <div id="search-result-wrapper" class="d-flex justify-content-center unloaded">
   <div class="col-11 post-content">
     <div id="search-hints">
-      {% include trending-tags.html %}
+      {% include_cached trending-tags.html %}
     </div>
     <div id="search-results" class="d-flex flex-wrap justify-content-center text-muted mt-3"></div>
   </div>

Environment

Command	Version
ruby -v	ruby 3.2.2 (2023-03-30 revision e51014f9c0) [arm64-darwin22]
gem -v	3.4.14
bundle -v	Bundler version 2.4.14
bundle exec jekyll -v	jekyll 4.3.2
bundle info jekyll-theme-chirpy	jekyll-theme-chirpy (6.0.1)

Desktop

• OS: [e.g. macOS 13.4]

[cotes2020]

Thank you for raising this issue, it is very detailed and has provided an improved solution. I will improve it as soon as possible.