Keep track of which projects are using which theme.

This is primarily used so we can send email to folks using alabaster,
and other themes we might want to display ads on.
This will allow us to give people fair warning before we put ads on their docs.

Author: ericholscher

readthedocs/donate/signals.py

@@ -1,14 +1,20 @@
 import random
+import logging
 
 from django.dispatch import receiver
 from django.conf import settings
+from django.core.cache import cache
+
+import redis
 
 from readthedocs.restapi.signals import footer_response
 from readthedocs.donate.models import SupporterPromo
 from readthedocs.donate.constants import INCLUDE, EXCLUDE
 from readthedocs.donate.utils import offer_promo
 
 
+log = logging.getLogger(__name__)
+
 PROMO_GEO_PATH = getattr(settings, 'PROMO_GEO_PATH', None)
 
 if PROMO_GEO_PATH:
@@ -200,3 +206,25 @@ def attach_promo_data(sender, **kwargs):
 
     # Set promo object on return JSON
     resp_data['promo'] = show_promo
+
+
+@receiver(footer_response)
+def index_theme_data(sender, **kwargs):
+    """
+    Keep track of which projects are using which theme.
+
+    This is primarily used so we can send email to folks using alabaster,
+    and other themes we might want to display ads on.
+    This will allow us to give people fair warning before we put ads on their docs.
+
+    """
+    context = kwargs['context']
+
+    project = context['project']
+    theme = context['theme']
+
+    try:
+        redis_client = cache.get_client(None)
+        redis_client.sadd("readthedocs:v1:index:themes:%s" % theme, project)
+    except (AttributeError, redis.exceptions.ConnectionError):
+        log.warning('Redis theme indexing error: %s', exc_info=True)