# HG changeset patch
# User Yuya Nishihara <yuya@tcha.org>
# Date 2018-11-28 13:36:24
# Node ID ff927ecb12f91b383a81ec438908995fb4d6b893
# Parent  76873548b051df5b966bc1e96d55c7e2df000a3d

ui: optimize buffered write with no label

This was spotted while making fastannotate faster again after ditching its
own formatter. Since I'm going to inline _write() into ui.write(), I decided
to include this patch in this series.

Here, the cost of '(self.label(a, label) for a in args)' was significant
in hot loops.

diff --git a/mercurial/ui.py b/mercurial/ui.py
--- a/mercurial/ui.py
+++ b/mercurial/ui.py
@@ -1006,8 +1006,8 @@ class ui(object):
 
     def _write(self, dest, *args, **opts):
         if self._isbuffered(dest):
-            if self._bufferapplylabels:
-                label = opts.get(r'label', '')
+            label = opts.get(r'label', '')
+            if label and self._bufferapplylabels:
                 self._buffers[-1].extend(self.label(a, label) for a in args)
             else:
                 self._buffers[-1].extend(args)