changeset 40925:008f3491dc53

perf: add perfprogress command

I've noticed that progress bars can add significant overhead to tight
loops. Let's add a perf command that attempts to isolate that overhead.

With a default hgrc, iteration over 1M items appears to take ~3.75s on
my machine. Profiling reveals ~28% of time is spent in ui.configbool()
resolving the value of the progress.debug config option.

Even if I set progress.disable=true, execution still takes ~2.60s, with
~59% of the time spent in ui.configbool().

Differential Revision: https://phab.mercurial-scm.org/D5407

--- a/contrib/perf.py	Mon Dec 10 18:55:08 2018 +0000
+++ b/contrib/perf.py	Mon Dec 10 20:01:07 2018 +0000
@@ -2612,3 +2612,21 @@
                                   hint=b"use 3.5 or later")
             return orig(repo, cmd, file_, opts)
         extensions.wrapfunction(cmdutil, b'openrevlog', openrevlog)
+
+@command(b'perfprogress', formatteropts + [
+    (b'', b'topic', b'topic', b'topic for progress messages'),
+    (b'c', b'total', 1000000, b'total value we are progressing to'),
+], norepo=True)
+def perfprogress(ui, topic=None, total=None, **opts):
+    """printing of progress bars"""
+    opts = _byteskwargs(opts)
+
+    timer, fm = gettimer(ui, opts)
+
+    def doprogress():
+        with ui.makeprogress(topic, total=total) as progress:
+            for i in pycompat.xrange(total):
+                progress.increment()
+
+    timer(doprogress)
+    fm.end()

--- a/tests/test-contrib-perf.t	Mon Dec 10 18:55:08 2018 +0000
+++ b/tests/test-contrib-perf.t	Mon Dec 10 20:01:07 2018 +0000
@@ -112,6 +112,7 @@
    perfphases    benchmark phasesets computation
    perfphasesremote
                  benchmark time needed to analyse phases of the remote server
+   perfprogress  printing of progress bars
    perfrawfiles  (no help text available)
    perfrevlogchunks
                  Benchmark operations on revlog chunks.
@@ -188,6 +189,7 @@
   $ hg perfmoonwalk
   $ hg perfnodelookup 2
   $ hg perfpathcopies 1 2
+  $ hg perfprogress --total 1000
   $ hg perfrawfiles 2
   $ hg perfrevlogindex -c
 #if reporevlogstore