changeset 41063:6603de284b0a

progress: avoid ui.configbool() lookup when progress bar is active Profiling revealed that the ui.configbool('progress', 'debug') during progress bar updates was consuming a significant amount of overhead. This commit adds an attribute on progress bar instances that caches this config option. The impact on `hg perfprogress` with default options is significant: before: ! wall 4.641942 comb 4.580000 user 4.210000 sys 0.370000 (best of 3) after: ! wall 1.948626 comb 1.950000 user 1.950000 sys 0.000000 (best of 5) After this change, profiling reveals that progress.progbar.progress() is now consuming ~73% of time. This change does not improve the execution time if the progress bar is disabled. We may want a more comprehensive solution for that case, as the progress bar won't be enabled in a number of scenarios (e.g. servers and processes not attached to an interactive TTY). I also think that overhead of ~2.0s for 1M updates is a bit high. I suspect further refactoring of the progress bar can significantly reduce overhead. I don't have plans to do this, however. Differential Revision: https://phab.mercurial-scm.org/D5408
author Gregory Szorc <gregory.szorc@gmail.com>
date Mon, 10 Dec 2018 20:06:58 +0000
parents 0a7f582f6f1f
children 4506f801e492
files mercurial/progress.py mercurial/ui.py
diffstat 2 files changed, 10 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/mercurial/progress.py	Sun Dec 23 22:57:03 2018 -0500
+++ b/mercurial/progress.py	Mon Dec 10 20:06:58 2018 +0000
@@ -104,6 +104,8 @@
         self.order = self.ui.configlist('progress', 'format')
         self.estimateinterval = self.ui.configwith(
             float, 'progress', 'estimateinterval')
+        # developer config: progress.debug
+        self.debug = self.ui.configbool('progress', 'debug')
 
     def show(self, now, topic, pos, item, unit, total):
         if not shouldprint(self.ui):
--- a/mercurial/ui.py	Sun Dec 23 22:57:03 2018 -0500
+++ b/mercurial/ui.py	Mon Dec 10 20:06:58 2018 +0000
@@ -1702,6 +1702,14 @@
         elif self._progbar is not None:
             self._progbar.progress(topic, pos, item=item, unit=unit,
                                    total=total)
+
+            # Looking up progress.debug in tight loops is expensive. The value
+            # is cached on the progbar object and we can avoid the lookup in
+            # the common case where a progbar is active.
+            if pos is None or not self._progbar.debug:
+                return
+
+        # Keep this logic in sync with above.
         if pos is None or not self.configbool('progress', 'debug'):
             return