General A/B testing.

[wolnelektury.git] / src / catalogue / helpers.py

diff --git a/src/catalogue/helpers.py b/src/catalogue/helpers.py
index 97c63d0..796ed04 100644 (file)
--- a/src/catalogue/helpers.py
+++ b/src/catalogue/helpers.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
 #
@@ -8,14 +7,14 @@ from django.core.cache import cache
 
 from .models import Tag, Book
 from os.path import getmtime
-import cPickle
+import pickle
 from collections import defaultdict
 
 
 BOOK_CATEGORIES = ('author', 'epoch', 'genre', 'kind')
 
 _COUNTERS = None
-_COUNTER_TIME = None
+_COUNTER_TIME = 0
 
 
 def get_top_level_related_tags(tags, categories=None):
@@ -28,8 +27,17 @@ def get_top_level_related_tags(tags, categories=None):
     global _COUNTERS, _COUNTER_TIME
     # First, check that we have a valid and recent version of the counters.
     if getmtime(settings.CATALOGUE_COUNTERS_FILE) > _COUNTER_TIME:
-        with open(settings.CATALOGUE_COUNTERS_FILE) as f:
-            _COUNTERS = cPickle.load(f)
+        for i in range(10):
+            try:
+                with open(settings.CATALOGUE_COUNTERS_FILE, 'rb') as f:
+                    _COUNTERS = pickle.load(f)
+            except (EOFError, ValueError):
+                if i < 9:
+                    continue
+                else:
+                    raise
+            else:
+                break
 
     tagids = tuple(sorted(t.pk for t in tags))
     try:
@@ -86,8 +94,8 @@ def update_counters():
         "next": dict(next_combinations),
     }
 
-    with open(settings.CATALOGUE_COUNTERS_FILE, 'w') as f:
-        cPickle.dump(counters, f)
+    with open(settings.CATALOGUE_COUNTERS_FILE, 'wb') as f:
+        pickle.dump(counters, f)
 
 
 def get_audiobook_tags():