# HG changeset patch
# User Boris Feld <boris.feld@octobus.net>
# Date 1542710780 0
# Node ID 594e84a2e57455ffa2069c9945e91ca737c74ca7
# Parent  415735bfcf2b1f33a3a53e557e0da85b6b7511e7
perf: add a `clear-revlogs` flag to `perftags`

This flag (on by default) makes it possible to disable the refresh of the
changelog and revlog. This is useful to check for the time spent in the core
tags logic without the associated side effects. Usually, these side effects
are shared with other logics (eg: bookmarks).

Example output in my Mercurial repository

$ hg perftags
! wall 0.017919 comb 0.020000 user 0.020000 sys 0.000000 (best of 141)
$ hg perftags --no-clear-revlogs
! wall 0.012982 comb 0.010000 user 0.010000 sys 0.000000 (best of 207)

diff -r 415735bfcf2b -r 594e84a2e574 contrib/perf.py
--- a/contrib/perf.py	Sun Nov 25 13:37:53 2018 +0100
+++ b/contrib/perf.py	Tue Nov 20 10:46:20 2018 +0000
@@ -538,14 +538,19 @@
     timer(d)
     fm.end()
 
-@command(b'perftags', formatteropts)
+@command(b'perftags', formatteropts+
+        [
+            (b'', b'clear-revlogs', True, b'refresh changelog and manifest'),
+        ])
 def perftags(ui, repo, **opts):
     opts = _byteskwargs(opts)
     timer, fm = gettimer(ui, opts)
     repocleartagscache = repocleartagscachefunc(repo)
+    clearrevlogs = opts[b'clear_revlogs']
     def s():
-        clearchangelog(repo)
-        clearfilecache(repo.unfiltered(), 'manifest')
+        if clearrevlogs:
+            clearchangelog(repo)
+            clearfilecache(repo.unfiltered(), 'manifest')
         repocleartagscache()
     def t():
         return len(repo.tags())