# HG changeset patch
# User Yuya Nishihara <yuya@tcha.org>
# Date 1543412184 -32400
# 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 -r 76873548b051 -r ff927ecb12f9 mercurial/ui.py
--- a/mercurial/ui.py	Wed Jan 23 18:07:42 2019 -0500
+++ b/mercurial/ui.py	Wed Nov 28 22:36:24 2018 +0900
@@ -1006,8 +1006,8 @@
 
     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)