From: Ben Darnell <ben@bendarnell.com>
Date: Mon, 2 May 2011 03:55:38 +0000 (-0700)
Subject: Speed up a common case in iostream._merge_prefix
X-Git-Tag: v2.0.0~87
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d762011c4b09e0a97bc610eddd5d89eb34dcbc7c;p=thirdparty%2Ftornado.git

Speed up a common case in iostream._merge_prefix
---

diff --git a/tornado/iostream.py b/tornado/iostream.py
index 02016a0f3..01df80544 100644
--- 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: