Speed up master key listing page

We were spending a lot of time getting the developer name for a given
key on this page, which involved sending one query per key ID. Use the
cache to our advantage here and save ourselves the "expensive" lookups.
This eliminates ~100 queries per page load.

Signed-off-by: Dan McGee <dan@archlinux.org>

2 files changed, 17 insertions, 9 deletions

diff --git a/main/templatetags/pgp.py b/main/templatetags/pgp.py
index e93e5bca..cc080439 100644
--- a/main/templatetags/pgp.py
+++ b/main/templatetags/pgp.py
@@ -3,6 +3,7 @@ from django.conf import settings
 from django.utils.html import conditional_escape
 from django.utils.safestring import mark_safe
 
+from ..utils import cache_function
 from devel.models import DeveloperKey
 
 register = template.Library()
@@ -42,15 +43,22 @@ def pgp_key_link(key_id, link_text=None):
     values = (url, format_key(key_id), link_text)
     return '<a href="%s" title="PGP key search for %s">%s</a>' % values
 
-@register.simple_tag
-def user_pgp_key_link(key_id):
-    normalized = key_id[-16:]
+
+@cache_function(1800)
+def name_for_key(normalized):
     try:
         matching_key = DeveloperKey.objects.select_related(
                 'owner').get(key=normalized, owner_id__isnull=False)
+        return matching_key.owner.get_full_name()
     except DeveloperKey.DoesNotExist:
-        return pgp_key_link(key_id)
-    return pgp_key_link(key_id, matching_key.owner.get_full_name())
+        return None
+
+
+@register.simple_tag
+def user_pgp_key_link(key_id):
+    normalized = key_id[-16:]
+    name = name_for_key(normalized)
+    return pgp_key_link(key_id, name)
 
 
 @register.filter(needs_autoescape=True)
diff --git a/templates/public/keys.html b/templates/public/keys.html
index c7272db3..54d52ab8 100644
--- a/templates/public/keys.html
+++ b/templates/public/keys.html
@@ -86,16 +86,16 @@
             </tr>
         </thead>
         <tbody>
-            {% for user in active_users %}
+            {% for user in active_users %}{% with user_key=user.userprofile.pgp_key %}
             <tr>
                 <th>{{ user.get_full_name }}</th>
-                <td>{% pgp_key_link user.userprofile.pgp_key %}</td>
+                <td>{% pgp_key_link user_key %}</td>
                 {% spaceless %}{% for key in keys %}
-                {% signature_exists signatures key.pgp_key user.userprofile.pgp_key as signed %}
+                {% signature_exists signatures key.pgp_key user_key as signed %}
                 <td class="signed-{{ signed|yesno }}">{{ signed|yesno|capfirst }}</td>
                 {% endfor %}{% endspaceless %}
             </tr>
-            {% endfor %}
+            {% endwith %}{% endfor %}
         </tbody>
     </table>
 </div>