Mercurial > hg
view mercurial/server.py @ 35787:a84dbc87dae9
exchange: send bundle2 stream clones uncompressed
Stream clones don't compress well. And compression undermines
a point of stream clones which is to trade significant CPU
reductions by increasing size.
Building upon our introduction of metadata to communicate bundle
information back to callers of exchange.getbundlechunks(), we add
an attribute to the bundler that communicates whether the bundle is
best left uncompressed. We return this attribute as part of the bundle
metadata. And the wire protocol honors it when determining whether
to compress the wire protocol response.
The added test demonstrates that the raw result from the wire
protocol is not compressed. It also demonstrates that the server
will serve stream responses when the feature isn't enabled. We'll
address that in another commit.
The effect of this change is that server-side CPU usage for bundle2
stream clones is significantly reduced by removing zstd compression.
For the mozilla-unified repository:
before: 37.69 user 8.01 system
after: 27.38 user 7.34 system
Assuming things are CPU bound, that ~10s reduction would translate to
faster clones on the client. zstd can decompress at >1 GB/s. So the
overhead from decompression on the client is small in the grand scheme
of things. But if zlib compression were being used, the overhead would
be much greater.
Differential Revision: https://phab.mercurial-scm.org/D1926
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Mon, 22 Jan 2018 12:12:29 -0800 |
parents | bfcd0d227972 |
children | d4a2e0d5d042 |
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# server.py - utility and factory of server # # Copyright 2005-2007 Matt Mackall <mpm@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. from __future__ import absolute_import import os import tempfile from .i18n import _ from . import ( chgserver, cmdutil, commandserver, error, hgweb, pycompat, util, ) def runservice(opts, parentfn=None, initfn=None, runfn=None, logfile=None, runargs=None, appendpid=False): '''Run a command as a service.''' def writepid(pid): if opts['pid_file']: if appendpid: mode = 'ab' else: mode = 'wb' fp = open(opts['pid_file'], mode) fp.write('%d\n' % pid) fp.close() if opts['daemon'] and not opts['daemon_postexec']: # Signal child process startup with file removal lockfd, lockpath = tempfile.mkstemp(prefix='hg-service-') os.close(lockfd) try: if not runargs: runargs = util.hgcmd() + pycompat.sysargv[1:] runargs.append('--daemon-postexec=unlink:%s' % lockpath) # Don't pass --cwd to the child process, because we've already # changed directory. for i in xrange(1, len(runargs)): if runargs[i].startswith('--cwd='): del runargs[i] break elif runargs[i].startswith('--cwd'): del runargs[i:i + 2] break def condfn(): return not os.path.exists(lockpath) pid = util.rundetached(runargs, condfn) if pid < 0: raise error.Abort(_('child process failed to start')) writepid(pid) finally: util.tryunlink(lockpath) if parentfn: return parentfn(pid) else: return if initfn: initfn() if not opts['daemon']: writepid(util.getpid()) if opts['daemon_postexec']: try: os.setsid() except AttributeError: pass for inst in opts['daemon_postexec']: if inst.startswith('unlink:'): lockpath = inst[7:] os.unlink(lockpath) elif inst.startswith('chdir:'): os.chdir(inst[6:]) elif inst != 'none': raise error.Abort(_('invalid value for --daemon-postexec: %s') % inst) util.hidewindow() util.stdout.flush() util.stderr.flush() nullfd = os.open(os.devnull, os.O_RDWR) logfilefd = nullfd if logfile: logfilefd = os.open(logfile, os.O_RDWR | os.O_CREAT | os.O_APPEND, 0o666) os.dup2(nullfd, 0) os.dup2(logfilefd, 1) os.dup2(logfilefd, 2) if nullfd not in (0, 1, 2): os.close(nullfd) if logfile and logfilefd not in (0, 1, 2): os.close(logfilefd) if runfn: return runfn() _cmdservicemap = { 'chgunix': chgserver.chgunixservice, 'pipe': commandserver.pipeservice, 'unix': commandserver.unixforkingservice, } def _createcmdservice(ui, repo, opts): mode = opts['cmdserver'] try: return _cmdservicemap[mode](ui, repo, opts) except KeyError: raise error.Abort(_('unknown mode %s') % mode) def _createhgwebservice(ui, repo, opts): # this way we can check if something was given in the command-line if opts.get('port'): opts['port'] = util.getport(opts.get('port')) alluis = {ui} if repo: baseui = repo.baseui alluis.update([repo.baseui, repo.ui]) else: baseui = ui webconf = opts.get('web_conf') or opts.get('webdir_conf') if webconf: if opts.get('subrepos'): raise error.Abort(_('--web-conf cannot be used with --subrepos')) # load server settings (e.g. web.port) to "copied" ui, which allows # hgwebdir to reload webconf cleanly servui = ui.copy() servui.readconfig(webconf, sections=['web']) alluis.add(servui) elif opts.get('subrepos'): servui = ui # If repo is None, hgweb.createapp() already raises a proper abort # message as long as webconf is None. if repo: webconf = dict() cmdutil.addwebdirpath(repo, "", webconf) else: servui = ui optlist = ("name templates style address port prefix ipv6" " accesslog errorlog certificate encoding") for o in optlist.split(): val = opts.get(o, '') if val in (None, ''): # should check against default options instead continue for u in alluis: u.setconfig("web", o, val, 'serve') app = hgweb.createapp(baseui, repo, webconf) return hgweb.httpservice(servui, app, opts) def createservice(ui, repo, opts): if opts["cmdserver"]: return _createcmdservice(ui, repo, opts) else: return _createhgwebservice(ui, repo, opts)