worker: change partition strategy to every Nth element
The only consumer of the worker pool code today is `hg update`.
Previously, the algorithm to partition work to each worker process
preserved input list ordering. We'd take the first N elements, then
the next N elements, etc. Measurements on mozilla-central demonstrate
this isn't an optimal partitioning strategy.
I added debug code to print when workers were exiting. When performing
a working copy update on a previously empty working copy of
mozilla-central, I noticed that process lifetimes were all over the
map. One worker would complete after 7s. Many would complete after
12s. And another worker would often take >16s. This behavior occurred
for many worker process counts and was more pronounced on some than
others.
What I suspect is happening is some workers end up with lots of
small files and others with large files. This is because the update
code passes in actions according to sorted filenames. And, directories
under tend to accumulate similar files. For example, test directories
often consist of many small test files and media directories contain
binary (often larger) media files.
This patch changes the partitioning algorithm to select every Nth
element from the input list. Each worker thus has a similar composition
of files to operate on.
The result of this change is that worker processes now all tend to exit
around the same time. The possibility of a long pole due to being
unlucky and receiving all the large files has been mitigated. Overall
execution time seems to drop, but not by a statistically significant
amount on mozilla-central. However, repositories with directories
containing many large files will likely show a drop.
There shouldn't be any regressions due to partial manifest decoding
because the update code already iterates the manifest to determine
what files to operate on, so the manifest should already be decoded.
# Copyright 2005, 2006 Benoit Boissinot <benoit.boissinot@ens-lyon.org>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''commands to sign and verify changesets'''
import os, tempfile, binascii
from mercurial import util, commands, match, cmdutil, error
from mercurial import node as hgnode
from mercurial.i18n import _
cmdtable = {}
command = cmdutil.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'internal' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'internal'
class gpg(object):
def __init__(self, path, key=None):
self.path = path
self.key = (key and " --local-user \"%s\"" % key) or ""
def sign(self, data):
gpgcmd = "%s --sign --detach-sign%s" % (self.path, self.key)
return util.filter(data, gpgcmd)
def verify(self, data, sig):
""" returns of the good and bad signatures"""
sigfile = datafile = None
try:
# create temporary files
fd, sigfile = tempfile.mkstemp(prefix="hg-gpg-", suffix=".sig")
fp = os.fdopen(fd, 'wb')
fp.write(sig)
fp.close()
fd, datafile = tempfile.mkstemp(prefix="hg-gpg-", suffix=".txt")
fp = os.fdopen(fd, 'wb')
fp.write(data)
fp.close()
gpgcmd = ("%s --logger-fd 1 --status-fd 1 --verify "
"\"%s\" \"%s\"" % (self.path, sigfile, datafile))
ret = util.filter("", gpgcmd)
finally:
for f in (sigfile, datafile):
try:
if f:
os.unlink(f)
except OSError:
pass
keys = []
key, fingerprint = None, None
for l in ret.splitlines():
# see DETAILS in the gnupg documentation
# filter the logger output
if not l.startswith("[GNUPG:]"):
continue
l = l[9:]
if l.startswith("VALIDSIG"):
# fingerprint of the primary key
fingerprint = l.split()[10]
elif l.startswith("ERRSIG"):
key = l.split(" ", 3)[:2]
key.append("")
fingerprint = None
elif (l.startswith("GOODSIG") or
l.startswith("EXPSIG") or
l.startswith("EXPKEYSIG") or
l.startswith("BADSIG")):
if key is not None:
keys.append(key + [fingerprint])
key = l.split(" ", 2)
fingerprint = None
if key is not None:
keys.append(key + [fingerprint])
return keys
def newgpg(ui, **opts):
"""create a new gpg instance"""
gpgpath = ui.config("gpg", "cmd", "gpg")
gpgkey = opts.get('key')
if not gpgkey:
gpgkey = ui.config("gpg", "key", None)
return gpg(gpgpath, gpgkey)
def sigwalk(repo):
"""
walk over every sigs, yields a couple
((node, version, sig), (filename, linenumber))
"""
def parsefile(fileiter, context):
ln = 1
for l in fileiter:
if not l:
continue
yield (l.split(" ", 2), (context, ln))
ln += 1
# read the heads
fl = repo.file(".hgsigs")
for r in reversed(fl.heads()):
fn = ".hgsigs|%s" % hgnode.short(r)
for item in parsefile(fl.read(r).splitlines(), fn):
yield item
try:
# read local signatures
fn = "localsigs"
for item in parsefile(repo.vfs(fn), fn):
yield item
except IOError:
pass
def getkeys(ui, repo, mygpg, sigdata, context):
"""get the keys who signed a data"""
fn, ln = context
node, version, sig = sigdata
prefix = "%s:%d" % (fn, ln)
node = hgnode.bin(node)
data = node2txt(repo, node, version)
sig = binascii.a2b_base64(sig)
keys = mygpg.verify(data, sig)
validkeys = []
# warn for expired key and/or sigs
for key in keys:
if key[0] == "ERRSIG":
ui.write(_("%s Unknown key ID \"%s\"\n")
% (prefix, shortkey(ui, key[1][:15])))
continue
if key[0] == "BADSIG":
ui.write(_("%s Bad signature from \"%s\"\n") % (prefix, key[2]))
continue
if key[0] == "EXPSIG":
ui.write(_("%s Note: Signature has expired"
" (signed by: \"%s\")\n") % (prefix, key[2]))
elif key[0] == "EXPKEYSIG":
ui.write(_("%s Note: This key has expired"
" (signed by: \"%s\")\n") % (prefix, key[2]))
validkeys.append((key[1], key[2], key[3]))
return validkeys
@command("sigs", [], _('hg sigs'))
def sigs(ui, repo):
"""list signed changesets"""
mygpg = newgpg(ui)
revs = {}
for data, context in sigwalk(repo):
node, version, sig = data
fn, ln = context
try:
n = repo.lookup(node)
except KeyError:
ui.warn(_("%s:%d node does not exist\n") % (fn, ln))
continue
r = repo.changelog.rev(n)
keys = getkeys(ui, repo, mygpg, data, context)
if not keys:
continue
revs.setdefault(r, [])
revs[r].extend(keys)
for rev in sorted(revs, reverse=True):
for k in revs[rev]:
r = "%5d:%s" % (rev, hgnode.hex(repo.changelog.node(rev)))
ui.write("%-30s %s\n" % (keystr(ui, k), r))
@command("sigcheck", [], _('hg sigcheck REV'))
def sigcheck(ui, repo, rev):
"""verify all the signatures there may be for a particular revision"""
mygpg = newgpg(ui)
rev = repo.lookup(rev)
hexrev = hgnode.hex(rev)
keys = []
for data, context in sigwalk(repo):
node, version, sig = data
if node == hexrev:
k = getkeys(ui, repo, mygpg, data, context)
if k:
keys.extend(k)
if not keys:
ui.write(_("no valid signature for %s\n") % hgnode.short(rev))
return
# print summary
ui.write("%s is signed by:\n" % hgnode.short(rev))
for key in keys:
ui.write(" %s\n" % keystr(ui, key))
def keystr(ui, key):
"""associate a string to a key (username, comment)"""
keyid, user, fingerprint = key
comment = ui.config("gpg", fingerprint, None)
if comment:
return "%s (%s)" % (user, comment)
else:
return user
@command("sign",
[('l', 'local', None, _('make the signature local')),
('f', 'force', None, _('sign even if the sigfile is modified')),
('', 'no-commit', None, _('do not commit the sigfile after signing')),
('k', 'key', '',
_('the key id to sign with'), _('ID')),
('m', 'message', '',
_('use text as commit message'), _('TEXT')),
('e', 'edit', False, _('invoke editor on commit messages')),
] + commands.commitopts2,
_('hg sign [OPTION]... [REV]...'))
def sign(ui, repo, *revs, **opts):
"""add a signature for the current or given revision
If no revision is given, the parent of the working directory is used,
or tip if no revision is checked out.
The ``gpg.cmd`` config setting can be used to specify the command
to run. A default key can be specified with ``gpg.key``.
See :hg:`help dates` for a list of formats valid for -d/--date.
"""
with repo.wlock():
return _dosign(ui, repo, *revs, **opts)
def _dosign(ui, repo, *revs, **opts):
mygpg = newgpg(ui, **opts)
sigver = "0"
sigmessage = ""
date = opts.get('date')
if date:
opts['date'] = util.parsedate(date)
if revs:
nodes = [repo.lookup(n) for n in revs]
else:
nodes = [node for node in repo.dirstate.parents()
if node != hgnode.nullid]
if len(nodes) > 1:
raise error.Abort(_('uncommitted merge - please provide a '
'specific revision'))
if not nodes:
nodes = [repo.changelog.tip()]
for n in nodes:
hexnode = hgnode.hex(n)
ui.write(_("signing %d:%s\n") % (repo.changelog.rev(n),
hgnode.short(n)))
# build data
data = node2txt(repo, n, sigver)
sig = mygpg.sign(data)
if not sig:
raise error.Abort(_("error while signing"))
sig = binascii.b2a_base64(sig)
sig = sig.replace("\n", "")
sigmessage += "%s %s %s\n" % (hexnode, sigver, sig)
# write it
if opts['local']:
repo.vfs.append("localsigs", sigmessage)
return
if not opts["force"]:
msigs = match.exact(repo.root, '', ['.hgsigs'])
if any(repo.status(match=msigs, unknown=True, ignored=True)):
raise error.Abort(_("working copy of .hgsigs is changed "),
hint=_("please commit .hgsigs manually"))
sigsfile = repo.wfile(".hgsigs", "ab")
sigsfile.write(sigmessage)
sigsfile.close()
if '.hgsigs' not in repo.dirstate:
repo[None].add([".hgsigs"])
if opts["no_commit"]:
return
message = opts['message']
if not message:
# we don't translate commit messages
message = "\n".join(["Added signature for changeset %s"
% hgnode.short(n)
for n in nodes])
try:
editor = cmdutil.getcommiteditor(editform='gpg.sign', **opts)
repo.commit(message, opts['user'], opts['date'], match=msigs,
editor=editor)
except ValueError as inst:
raise error.Abort(str(inst))
def shortkey(ui, key):
if len(key) != 16:
ui.debug("key ID \"%s\" format error\n" % key)
return key
return key[-8:]
def node2txt(repo, node, ver):
"""map a manifest into some text"""
if ver == "0":
return "%s\n" % hgnode.hex(node)
else:
raise error.Abort(_("unknown signature version"))