branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
#!/usr/bin/env python3
#
# hgperf - measure performance of Mercurial commands
#
# Copyright 2014 Olivia Mackall <olivia@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''measure performance of Mercurial commands
Using ``hgperf`` instead of ``hg`` measures performance of the target
Mercurial command. For example, the execution below measures
performance of :hg:`heads --topo`::
$ hgperf heads --topo
All command output via ``ui`` is suppressed, and just measurement
result is displayed: see also "perf" extension in "contrib".
Costs of processing before dispatching to the command function like
below are not measured::
- parsing command line (e.g. option validity check)
- reading configuration files in
But ``pre-`` and ``post-`` hook invocation for the target command is
measured, even though these are invoked before or after dispatching to
the command function, because these may be required to repeat
execution of the target command correctly.
'''
import os
import sys
libdir = '@LIBDIR@'
if libdir != '@' 'LIBDIR' '@':
if not os.path.isabs(libdir):
libdir = os.path.join(
os.path.dirname(os.path.realpath(__file__)), libdir
)
libdir = os.path.abspath(libdir)
sys.path.insert(0, libdir)
# enable importing on demand to reduce startup time
try:
from mercurial import demandimport
demandimport.enable()
except ImportError:
import sys
sys.stderr.write(
"abort: couldn't find mercurial libraries in [%s]\n"
% ' '.join(sys.path)
)
sys.stderr.write("(check your install and PYTHONPATH)\n")
sys.exit(-1)
from mercurial import (
dispatch,
util,
)
def timer(func, title=None):
results = []
begin = util.timer()
count = 0
while True:
ostart = os.times()
cstart = util.timer()
r = func()
cstop = util.timer()
ostop = os.times()
count += 1
a, b = ostart, ostop
results.append((cstop - cstart, b[0] - a[0], b[1] - a[1]))
if cstop - begin > 3 and count >= 100:
break
if cstop - begin > 10 and count >= 3:
break
if title:
sys.stderr.write("! %s\n" % title)
if r:
sys.stderr.write("! result: %s\n" % r)
m = min(results)
sys.stderr.write(
"! wall %f comb %f user %f sys %f (best of %d)\n"
% (m[0], m[1] + m[2], m[1], m[2], count)
)
orgruncommand = dispatch.runcommand
def runcommand(lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions):
ui.pushbuffer()
lui.pushbuffer()
timer(
lambda: orgruncommand(
lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions
)
)
ui.popbuffer()
lui.popbuffer()
dispatch.runcommand = runcommand
dispatch.run()