Micro-optimize paginations

mitsuhiko · mitsuhiko · commit deb5a7a91d48 · 2013-01-27T01:26:58.000Z
diff --git a/flask_sqlalchemy.py b/flask_sqlalchemy.py
@@ -385,7 +385,15 @@ def paginate(self, page, per_page=20, error_out=True):
         items = self.limit(per_page).offset((page - 1) * per_page).all()
         if not items and page != 1 and error_out:
             abort(404)
-        return Pagination(self, page, per_page, self.order_by(None).count(), items)
+
+        # No need to count if we're on the first page and there are fewer
+        # items than we expected.
+        if page == 1 and len(items) < per_page:
+            total = len(items)
+        else:
+            total = self.order_by(None).count()
+
+        return Pagination(self, page, per_page, total, items)
 
 
 class _QueryProperty(object):
