util: fix race in makedirs()
Update makedirs() to ignore EEXIST in case someone else has already created the
directory in question. Previously the ensuredirs() function existed, and was
nearly identical to makedirs() except that it fixed this race. Unfortunately
ensuredirs() was only used in 3 places, and most code uses the racy makedirs()
function. This fixes makedirs() to be non-racy, and replaces calls to
ensuredirs() with makedirs().
In particular, mercurial.scmutil.origpath() used the racy makedirs() code,
which could cause failures during "hg update" as it tried to create backup
directories.
This does slightly change the behavior of call sites using ensuredirs():
previously ensuredirs() would throw EEXIST if the path existed but was a
regular file instead of a directory. It did this by explicitly checking
os.path.isdir() after getting EEXIST. The makedirs() code did not do this and
swallowed all EEXIST errors. I kept the makedirs() behavior, since it seemed
preferable to avoid the extra stat call in the common case where this directory
already exists. If the path does happen to be a file, the caller will almost
certainly fail with an ENOTDIR error shortly afterwards anyway. I checked
the 3 existing call sites of ensuredirs(), and this seems to be the case for
them.
#!/usr/bin/env python
# Measure the performance of a list of revsets against multiple revisions
# defined by parameter. Checkout one by one and run perfrevset with every
# revset in the list to benchmark its performance.
#
# You should run this from the root of your mercurial repository.
#
# call with --help for details
from __future__ import absolute_import, print_function
import math
import os
import re
import sys
from subprocess import (
CalledProcessError,
check_call,
PIPE,
Popen,
STDOUT,
)
# cannot use argparse, python 2.7 only
from optparse import (
OptionParser,
)
DEFAULTVARIANTS = ['plain', 'min', 'max', 'first', 'last',
'reverse', 'reverse+first', 'reverse+last',
'sort', 'sort+first', 'sort+last']
def check_output(*args, **kwargs):
kwargs.setdefault('stderr', PIPE)
kwargs.setdefault('stdout', PIPE)
proc = Popen(*args, **kwargs)
output, error = proc.communicate()
if proc.returncode != 0:
raise CalledProcessError(proc.returncode, ' '.join(args[0]))
return output
def update(rev):
"""update the repo to a revision"""
try:
check_call(['hg', 'update', '--quiet', '--check', str(rev)])
check_output(['make', 'local'],
stderr=None) # suppress output except for error/warning
except CalledProcessError as exc:
print('update to revision %s failed, aborting'%rev, file=sys.stderr)
sys.exit(exc.returncode)
def hg(cmd, repo=None):
"""run a mercurial command
<cmd> is the list of command + argument,
<repo> is an optional repository path to run this command in."""
fullcmd = ['./hg']
if repo is not None:
fullcmd += ['-R', repo]
fullcmd += ['--config',
'extensions.perf=' + os.path.join(contribdir, 'perf.py')]
fullcmd += cmd
return check_output(fullcmd, stderr=STDOUT)
def perf(revset, target=None, contexts=False):
"""run benchmark for this very revset"""
try:
args = ['perfrevset', revset]
if contexts:
args.append('--contexts')
output = hg(args, repo=target)
return parseoutput(output)
except CalledProcessError as exc:
print('abort: cannot run revset benchmark: %s'%exc.cmd, file=sys.stderr)
if getattr(exc, 'output', None) is None: # no output before 2.7
print('(no output)', file=sys.stderr)
else:
print(exc.output, file=sys.stderr)
return None
outputre = re.compile(r'! wall (\d+.\d+) comb (\d+.\d+) user (\d+.\d+) '
'sys (\d+.\d+) \(best of (\d+)\)')
def parseoutput(output):
"""parse a textual output into a dict
We cannot just use json because we want to compare with old
versions of Mercurial that may not support json output.
"""
match = outputre.search(output)
if not match:
print('abort: invalid output:', file=sys.stderr)
print(output, file=sys.stderr)
sys.exit(1)
return {'comb': float(match.group(2)),
'count': int(match.group(5)),
'sys': float(match.group(3)),
'user': float(match.group(4)),
'wall': float(match.group(1)),
}
def printrevision(rev):
"""print data about a revision"""
sys.stdout.write("Revision ")
sys.stdout.flush()
check_call(['hg', 'log', '--rev', str(rev), '--template',
'{if(tags, " ({tags})")} '
'{rev}:{node|short}: {desc|firstline}\n'])
def idxwidth(nbidx):
"""return the max width of number used for index
This is similar to log10(nbidx), but we use custom code here
because we start with zero and we'd rather not deal with all the
extra rounding business that log10 would imply.
"""
nbidx -= 1 # starts at 0
idxwidth = 0
while nbidx:
idxwidth += 1
nbidx //= 10
if not idxwidth:
idxwidth = 1
return idxwidth
def getfactor(main, other, field, sensitivity=0.05):
"""return the relative factor between values for 'field' in main and other
Return None if the factor is insignificant (less than <sensitivity>
variation)."""
factor = 1
if main is not None:
factor = other[field] / main[field]
low, high = 1 - sensitivity, 1 + sensitivity
if (low < factor < high):
return None
return factor
def formatfactor(factor):
"""format a factor into a 4 char string
22%
156%
x2.4
x23
x789
x1e4
x5x7
"""
if factor is None:
return ' '
elif factor < 2:
return '%3i%%' % (factor * 100)
elif factor < 10:
return 'x%3.1f' % factor
elif factor < 1000:
return '%4s' % ('x%i' % factor)
else:
order = int(math.log(factor)) + 1
while 1 < math.log(factor):
factor //= 0
return 'x%ix%i' % (factor, order)
def formattiming(value):
"""format a value to strictly 8 char, dropping some precision if needed"""
if value < 10**7:
return ('%.6f' % value)[:8]
else:
# value is HUGE very unlikely to happen (4+ month run)
return '%i' % value
_marker = object()
def printresult(variants, idx, data, maxidx, verbose=False, reference=_marker):
"""print a line of result to stdout"""
mask = '%%0%ii) %%s' % idxwidth(maxidx)
out = []
for var in variants:
if data[var] is None:
out.append('error ')
out.append(' ' * 4)
continue
out.append(formattiming(data[var]['wall']))
if reference is not _marker:
factor = None
if reference is not None:
factor = getfactor(reference[var], data[var], 'wall')
out.append(formatfactor(factor))
if verbose:
out.append(formattiming(data[var]['comb']))
out.append(formattiming(data[var]['user']))
out.append(formattiming(data[var]['sys']))
out.append('%6d' % data[var]['count'])
print(mask % (idx, ' '.join(out)))
def printheader(variants, maxidx, verbose=False, relative=False):
header = [' ' * (idxwidth(maxidx) + 1)]
for var in variants:
if not var:
var = 'iter'
if 8 < len(var):
var = var[:3] + '..' + var[-3:]
header.append('%-8s' % var)
if relative:
header.append(' ')
if verbose:
header.append('%-8s' % 'comb')
header.append('%-8s' % 'user')
header.append('%-8s' % 'sys')
header.append('%6s' % 'count')
print(' '.join(header))
def getrevs(spec):
"""get the list of rev matched by a revset"""
try:
out = check_output(['hg', 'log', '--template={rev}\n', '--rev', spec])
except CalledProcessError as exc:
print("abort, can't get revision from %s"%spec, file=sys.stderr)
sys.exit(exc.returncode)
return [r for r in out.split() if r]
def applyvariants(revset, variant):
if variant == 'plain':
return revset
for var in variant.split('+'):
revset = '%s(%s)' % (var, revset)
return revset
helptext="""This script will run multiple variants of provided revsets using
different revisions in your mercurial repository. After the benchmark are run
summary output is provided. Use it to demonstrate speed improvements or pin
point regressions. Revsets to run are specified in a file (or from stdin), one
revsets per line. Line starting with '#' will be ignored, allowing insertion of
comments."""
parser = OptionParser(usage="usage: %prog [options] <revs>",
description=helptext)
parser.add_option("-f", "--file",
help="read revset from FILE (stdin if omitted)",
metavar="FILE")
parser.add_option("-R", "--repo",
help="run benchmark on REPO", metavar="REPO")
parser.add_option("-v", "--verbose",
action='store_true',
help="display all timing data (not just best total time)")
parser.add_option("", "--variants",
default=','.join(DEFAULTVARIANTS),
help="comma separated list of variant to test "
"(eg: plain,min,sorted) (plain = no modification)")
parser.add_option('', '--contexts',
action='store_true',
help='obtain changectx from results instead of integer revs')
(options, args) = parser.parse_args()
if not args:
parser.print_help()
sys.exit(255)
# the directory where both this script and the perf.py extension live.
contribdir = os.path.dirname(__file__)
revsetsfile = sys.stdin
if options.file:
revsetsfile = open(options.file)
revsets = [l.strip() for l in revsetsfile if not l.startswith('#')]
revsets = [l for l in revsets if l]
print("Revsets to benchmark")
print("----------------------------")
for idx, rset in enumerate(revsets):
print("%i) %s" % (idx, rset))
print("----------------------------")
print()
revs = []
for a in args:
revs.extend(getrevs(a))
variants = options.variants.split(',')
results = []
for r in revs:
print("----------------------------")
printrevision(r)
print("----------------------------")
update(r)
res = []
results.append(res)
printheader(variants, len(revsets), verbose=options.verbose)
for idx, rset in enumerate(revsets):
varres = {}
for var in variants:
varrset = applyvariants(rset, var)
data = perf(varrset, target=options.repo, contexts=options.contexts)
varres[var] = data
res.append(varres)
printresult(variants, idx, varres, len(revsets),
verbose=options.verbose)
sys.stdout.flush()
print("----------------------------")
print("""
Result by revset
================
""")
print('Revision:')
for idx, rev in enumerate(revs):
sys.stdout.write('%i) ' % idx)
sys.stdout.flush()
printrevision(rev)
print()
print()
for ridx, rset in enumerate(revsets):
print("revset #%i: %s" % (ridx, rset))
printheader(variants, len(results), verbose=options.verbose, relative=True)
ref = None
for idx, data in enumerate(results):
printresult(variants, idx, data[ridx], len(results),
verbose=options.verbose, reference=ref)
ref = data[ridx]
print()