-def related_books(book, limit=6):
- related = list(Book.objects.filter(
- common_slug=book.common_slug).exclude(pk=book.pk)[:limit])
- limit -= len(related)
- if limit:
- related += Book.tagged.related_to(book,
- Book.objects.exclude(common_slug=book.common_slug),
- ignore_by_tag=book.book_tag())[:limit]
+def related_books(book, limit=6, random=1):
+ cache_key = "catalogue.related_books.%d.%d" % (book.id, limit - random)
+ related = cache.get(cache_key)
+ if related is None:
+ related = list(Book.objects.filter(
+ common_slug=book.common_slug).exclude(pk=book.pk)[:limit])
+ limit -= len(related)
+ if limit > random:
+ related += Book.tagged.related_to(book,
+ Book.objects.exclude(common_slug=book.common_slug),
+ ignore_by_tag=book.book_tag())[:limit-random]
+ cache.set(cache_key, related, 1800)
+ if random:
+ related += list(Book.objects.exclude(
+ pk__in=[b.pk for b in related] + [book.pk]
+ ).order_by('?')[:random])