Minify the cache tags sent in the header

I'm testing (and reading) the patch #57.

+/**
+ * Implements hook_purge_cache_tags_simplify_dictionary().
+ */
+function purge_purge_cache_tags_simplify_dictionary() {
+  // Most common list cache tags.
+  return [
+    'config:block_list' => '/^config\:block\./',
+    'menu_link_content_list' => '/^menu_link_content\:/',
+    'media_list' => '/^media\:/',
+    'node_list' => '/^node\:/',
+    'file_list' => '/^file\:/',
+    'taxonomy_term_list' => '/^taxonomy_term\:/',
+    'user_list' => '/^user\:/',
+  ];
+}

Could somebody please elaborate once more what's the conceptual logic behind this?

Isn't it so that:

• An individual node page, will only have node:42 cache tag
• But a View that renders nodes will have also node_list (and node_list:) so that whenever new nodes have been created, the Views that render these nodes will be invalidated.

So are we throwing away the node:xxx tags if and only if also the node_list tag is also present? In other words, the individual node pages would still have the node:xxx cache tags?

If my thinking-out-loud is correct here, can we please elaborate the documentation block of purge_purge_cache_tags_simplify_dictionary()?

Cheers,
Markus

I'm not sure how helpful this comment is, but I tried the patch in #54 and got the following error.

The website encountered an unexpected error. Please try again later.
ArgumentCountError: Too few arguments to function Drupal\purge\Plugin\Purge\TagsHeader\TagsHeaderBase::__construct(), 3 passed in /var/www/html/docroot/modules/contrib/acquia_purge/src/Plugin/Purge/TagsHeader/AcquiaCloudSiteHeader.php on line 41 and exactly 4 expected in Drupal\purge\Plugin\Purge\TagsHeader\TagsHeaderBase->__construct() (line 32 of modules/contrib/purge/src/Plugin/Purge/TagsHeader/TagsHeaderBase.php). 

I had to switch to other work and didn't have time to look into the error, but I will update the thread if I do. Posting since someone else might encounter the error or know how to fix in a patch.

Okay, the relevant patch in the Acquia Purge module is here and it says to re-roll into this patch: https://www.drupal.org/project/acquia_purge/issues/3157178 →

I will look into this now in my local dev environment.

Rerolled #57 for latest version.

I'm not a fan of the hashing solution as you have no idea what the content is. The dictionary looks like a lot of work to maintain.
As an alternative method I added compression strategy, keeping only the first letter of each word. It is fully automated and you could still retrieve the original cache tag.

As you should still have the option to disable minification logic completely, I changed the configuration form to a select.
Example minitication ratios (number of characters in the cache tags header):

• None: 4030
• Dictionary: 2337
• Compress: 1300
• Hash: 734

Replacing incorrect patch

I tested patch #63 and it seems to be failing for 8.x-3.4.