Cache generated HTML

favicon/models.py

 from io import BytesIO
+import hashlib
+import json
 import sys
 
 from PIL import Image
 from django.conf import settings
+from django.core.cache import cache
 from django.core.files.storage import default_storage as storage
 from django.core.files.uploadedfile import InMemoryUploadedFile
 from django.db import models
@@ -26,6 +29,8 @@ config = getattr(settings, 'FAVICON_CONFIG', config)
 if "shortcut icon" not in config or 32 not in config["shortcut icon"]:
     config.setdefault("shortcut_icon", []).append(32)
 
+config_cache_key = "favicons_" + hashlib.sha1(json.dumps(config, sort_keys=True).encode()).hexdigest()
+
 image_path = getattr(settings, "FAVICON_PATH", "favicon")
 
 
@@ -112,6 +117,8 @@ class Favicon(models.Model):
         if self.faviconImage:
             self.get_favicons(update=update)
 
+        cache.delete(config_cache_key)
+
 
 class FaviconImg(models.Model):
     faviconFK = models.ForeignKey(Favicon, on_delete=models.CASCADE)

favicon/templatetags/favtags.py

 from django import template
+from django.core.cache import cache
 from django.utils.safestring import mark_safe
 
-from favicon.models import Favicon, config
+from favicon.models import Favicon, config_cache_key
 
 register = template.Library()
 
@@ -16,6 +17,11 @@ def place_favicon(context):
         {% place_favicon %}
 
     """
+
+    html = cache.get(config_cache_key)
+    if html:
+        return html
+
     fav = Favicon.on_site.filter(isFavicon=True).first()
     if not fav:
         return mark_safe('<!-- no favicon -->')
@@ -23,4 +29,5 @@ def place_favicon(context):
     for n in fav.get_favicons():
         html += f'<link rel="{n.rel}" sizes="{n.size}x{n.size}" href="{n.faviconImage.url}"/>'
 
+    cache.set(config_cache_key, html, timeout=None)
     return mark_safe(html)