Speed up a common case in iostream._merge_prefix

jamessa · May 2, 2011 · d762011 · d762011
1 parent 3cc7f2c
commit d762011
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/tornado/iostream.py b/tornado/iostream.py
@@ -516,6 +516,8 @@ def _merge_prefix(deque, size):
     >>> _merge_prefix(d, 100); print d
     deque(['abcdefghij'])
     """
+    if len(deque) == 1 and len(deque[0]) < size:
+        return
     prefix = []
     remaining = size
     while deque and remaining > 0: