Remove race condition in building ebooks.

[wolnelektury.git] / src / wolnelektury / views.py

diff --git a/src/wolnelektury/views.py b/src/wolnelektury/views.py
index 415a4fd..1c0f40c 100644 (file)
--- a/src/wolnelektury/views.py
+++ b/src/wolnelektury/views.py
@@ -52,7 +52,21 @@ def main_page(request):
     except IndexError:
         pass
 
     except IndexError:
         pass
 

-    ctx['best'] = Book.objects.filter(findable=True).order_by('?')[:5]
+    best = []
+    best_places = 5
+    for recommended in Collection.objects.filter(role='recommend').order_by('?'):
+        books = list(recommended.get_books().exclude(id__in=[b.id for b in best]).order_by('?')[:best_places])
+        best.extend(books)
+        best_places -= len(books)
+        if not best_places:
+            break
+    if best_places:
+        best.extend(
+            list(
+                Book.objects.filter(findable=True).exclude(id__in=[b.id for b in best]).order_by('?')[:best_places]
+            )
+        )
+    ctx['best'] = best

 
     return render(request, "main_page.html", ctx)
 
 
     return render(request, "main_page.html", ctx)