euscanwww: add missing file

Signed-off-by: Corentin Chary <corentin.chary@gmail.com>

euscanwww/djeuscan/utils.py

@@ -0,0 +1,22 @@
+
+def queryset_iterator(queryset, chunksize=1000):
+        '''''
+        Iterate over a Django Queryset ordered by the primary key
+
+        This method loads a maximum of chunksize (default: 1000) rows in it's
+        memory at the same time while django normally would load all rows in it's
+        memory. Using the iterator() method only causes it to not preload all the
+        classes.
+
+        Note that the implementation of the iterator does not support ordered query sets.
+        '''
+        import gc
+
+        pk = 0
+        last_pk = queryset.order_by('-pk')[0].pk
+        queryset = queryset.order_by('pk')
+        while pk < last_pk:
+            for row in queryset.filter(pk__gt=pk)[:chunksize]:
+                pk = row.pk
+                yield row
+            gc.collect()