Mercurial > hg
view mercurial/hgweb/hgwebdir_mod.py @ 47802:de2e04fe4897
hgwebdir: avoid systematic full garbage collection
Forcing a systematic full garbage collection upon each request
can serioulsy harm performance. This is reported as
https://bz.mercurial-scm.org/show_bug.cgi?id=6075
With this change we're performing the full collection according
to a new setting, `experimental.web.full-garbage-collection-rate`.
The default value is 1, which doesn't change the behavior and will
allow us to test on real use cases. If the value is 0, no full garbage
collection occurs.
Regardless of the value of the setting, a partial garbage collection
still occurs upon each request (not attempting to collect objects from
the oldest generation). This should be enough to take care of
reference cycles that have been created by the last request
(assessment of this requires changing the setting, not to be 1).
In my experience chasing memory leaks in Mercurial servers,
the full collection never reclaimed any memory, but this is with
Python 3 and biased towards small repositories.
On the other hand, as explained in the Python developer docs [1],
frequent full collections are very harmful in terms of performance if
lots of objects survive the collection, and hence stay in the
oldest generation. Note that `gc.collect()` is indeed trying to
collect the oldest generation [2]. This happens usually in two cases:
- unwanted lingering objects (i.e., an actual memory leak that
the GC cannot do anything about). Sadly, we have lots of those
these days.
- desireable long-term objects, typically in caches (not inner caches
carried by repositories, which should be collected with them). This
is a subject of interest for the Heptapod project.
In short, the flat rate that this change still permits is
probably a bad idea in most cases, and the default value can
be tweaked later on (or even be set to 0) according to experiments
in the wild.
The test is inspired from test-hgwebdir-paths.py
[1] https://devguide.python.org/garbage_collector/#collecting-the-oldest-generation
[2] https://docs.python.org/3/library/gc.html#gc.collect
Differential Revision: https://phab.mercurial-scm.org/D11204
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 20 Jul 2021 17:20:19 +0200 |
parents | aceede7c4929 |
children | 6000f5b25c9b |
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# hgweb/hgwebdir_mod.py - Web interface for a directory of repositories. # # Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net> # Copyright 2005, 2006 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. from __future__ import absolute_import import gc import os import time from ..i18n import _ from .common import ( ErrorResponse, HTTP_SERVER_ERROR, cspvalues, get_contact, get_mtime, ismember, paritygen, staticfile, statusmessage, ) from .. import ( configitems, encoding, error, extensions, hg, pathutil, profiling, pycompat, rcutil, registrar, scmutil, templater, templateutil, ui as uimod, util, ) from . import ( hgweb_mod, request as requestmod, webutil, wsgicgi, ) from ..utils import dateutil def cleannames(items): return [(util.pconvert(name).strip(b'/'), path) for name, path in items] def findrepos(paths): repos = [] for prefix, root in cleannames(paths): roothead, roottail = os.path.split(root) # "foo = /bar/*" or "foo = /bar/**" lets every repo /bar/N in or below # /bar/ be served as as foo/N . # '*' will not search inside dirs with .hg (except .hg/patches), # '**' will search inside dirs with .hg (and thus also find subrepos). try: recurse = {b'*': False, b'**': True}[roottail] except KeyError: repos.append((prefix, root)) continue roothead = os.path.normpath(util.abspath(roothead)) paths = scmutil.walkrepos(roothead, followsym=True, recurse=recurse) repos.extend(urlrepos(prefix, roothead, paths)) return repos def urlrepos(prefix, roothead, paths): """yield url paths and filesystem paths from a list of repo paths >>> conv = lambda seq: [(v, util.pconvert(p)) for v,p in seq] >>> conv(urlrepos(b'hg', b'/opt', [b'/opt/r', b'/opt/r/r', b'/opt'])) [('hg/r', '/opt/r'), ('hg/r/r', '/opt/r/r'), ('hg', '/opt')] >>> conv(urlrepos(b'', b'/opt', [b'/opt/r', b'/opt/r/r', b'/opt'])) [('r', '/opt/r'), ('r/r', '/opt/r/r'), ('', '/opt')] """ for path in paths: path = os.path.normpath(path) yield ( prefix + b'/' + util.pconvert(path[len(roothead) :]).lstrip(b'/') ).strip(b'/'), path def readallowed(ui, req): """Check allow_read and deny_read config options of a repo's ui object to determine user permissions. By default, with neither option set (or both empty), allow all users to read the repo. There are two ways a user can be denied read access: (1) deny_read is not empty, and the user is unauthenticated or deny_read contains user (or *), and (2) allow_read is not empty and the user is not in allow_read. Return True if user is allowed to read the repo, else return False.""" user = req.remoteuser deny_read = ui.configlist(b'web', b'deny_read', untrusted=True) if deny_read and (not user or ismember(ui, user, deny_read)): return False allow_read = ui.configlist(b'web', b'allow_read', untrusted=True) # by default, allow reading if no allow_read option has been set if not allow_read or ismember(ui, user, allow_read): return True return False def rawindexentries(ui, repos, req, subdir=b''): descend = ui.configbool(b'web', b'descend') collapse = ui.configbool(b'web', b'collapse') seenrepos = set() seendirs = set() for name, path in repos: if not name.startswith(subdir): continue name = name[len(subdir) :] directory = False if b'/' in name: if not descend: continue nameparts = name.split(b'/') rootname = nameparts[0] if not collapse: pass elif rootname in seendirs: continue elif rootname in seenrepos: pass else: directory = True name = rootname # redefine the path to refer to the directory discarded = b'/'.join(nameparts[1:]) # remove name parts plus accompanying slash path = path[: -len(discarded) - 1] try: hg.repository(ui, path) directory = False except (IOError, error.RepoError): pass parts = [ req.apppath.strip(b'/'), subdir.strip(b'/'), name.strip(b'/'), ] url = b'/' + b'/'.join(p for p in parts if p) + b'/' # show either a directory entry or a repository if directory: # get the directory's time information try: d = (get_mtime(path), dateutil.makedate()[1]) except OSError: continue # add '/' to the name to make it obvious that # the entry is a directory, not a regular repository row = { b'contact': b"", b'contact_sort': b"", b'name': name + b'/', b'name_sort': name, b'url': url, b'description': b"", b'description_sort': b"", b'lastchange': d, b'lastchange_sort': d[1] - d[0], b'archives': templateutil.mappinglist([]), b'isdirectory': True, b'labels': templateutil.hybridlist([], name=b'label'), } seendirs.add(name) yield row continue u = ui.copy() if rcutil.use_repo_hgrc(): try: u.readconfig(os.path.join(path, b'.hg', b'hgrc')) except Exception as e: u.warn(_(b'error reading %s/.hg/hgrc: %s\n') % (path, e)) continue def get(section, name, default=uimod._unset): return u.config(section, name, default, untrusted=True) if u.configbool(b"web", b"hidden", untrusted=True): continue if not readallowed(u, req): continue # update time with local timezone try: r = hg.repository(ui, path) except IOError: u.warn(_(b'error accessing repository at %s\n') % path) continue except error.RepoError: u.warn(_(b'error accessing repository at %s\n') % path) continue try: d = (get_mtime(r.spath), dateutil.makedate()[1]) except OSError: continue contact = get_contact(get) description = get(b"web", b"description") seenrepos.add(name) name = get(b"web", b"name", name) labels = u.configlist(b'web', b'labels', untrusted=True) row = { b'contact': contact or b"unknown", b'contact_sort': contact.upper() or b"unknown", b'name': name, b'name_sort': name, b'url': url, b'description': description or b"unknown", b'description_sort': description.upper() or b"unknown", b'lastchange': d, b'lastchange_sort': d[1] - d[0], b'archives': webutil.archivelist(u, b"tip", url), b'isdirectory': None, b'labels': templateutil.hybridlist(labels, name=b'label'), } yield row def _indexentriesgen( context, ui, repos, req, stripecount, sortcolumn, descending, subdir ): rows = rawindexentries(ui, repos, req, subdir=subdir) sortdefault = None, False if sortcolumn and sortdefault != (sortcolumn, descending): sortkey = b'%s_sort' % sortcolumn rows = sorted(rows, key=lambda x: x[sortkey], reverse=descending) for row, parity in zip(rows, paritygen(stripecount)): row[b'parity'] = parity yield row def indexentries( ui, repos, req, stripecount, sortcolumn=b'', descending=False, subdir=b'' ): args = (ui, repos, req, stripecount, sortcolumn, descending, subdir) return templateutil.mappinggenerator(_indexentriesgen, args=args) class hgwebdir(object): """HTTP server for multiple repositories. Given a configuration, different repositories will be served depending on the request path. Instances are typically used as WSGI applications. """ def __init__(self, conf, baseui=None): self.conf = conf self.baseui = baseui self.ui = None self.lastrefresh = 0 self.motd = None self.refresh() self.requests_count = 0 if not baseui: # set up environment for new ui extensions.loadall(self.ui) extensions.populateui(self.ui) def refresh(self): if self.ui: refreshinterval = self.ui.configint(b'web', b'refreshinterval') else: item = configitems.coreitems[b'web'][b'refreshinterval'] refreshinterval = item.default # refreshinterval <= 0 means to always refresh. if ( refreshinterval > 0 and self.lastrefresh + refreshinterval > time.time() ): return if self.baseui: u = self.baseui.copy() else: u = uimod.ui.load() u.setconfig(b'ui', b'report_untrusted', b'off', b'hgwebdir') u.setconfig(b'ui', b'nontty', b'true', b'hgwebdir') # displaying bundling progress bar while serving feels wrong and may # break some wsgi implementations. u.setconfig(b'progress', b'disable', b'true', b'hgweb') if not isinstance(self.conf, (dict, list, tuple)): map = {b'paths': b'hgweb-paths'} if not os.path.exists(self.conf): raise error.Abort(_(b'config file %s not found!') % self.conf) u.readconfig(self.conf, remap=map, trust=True) paths = [] for name, ignored in u.configitems(b'hgweb-paths'): for path in u.configlist(b'hgweb-paths', name): paths.append((name, path)) elif isinstance(self.conf, (list, tuple)): paths = self.conf elif isinstance(self.conf, dict): paths = self.conf.items() extensions.populateui(u) repos = findrepos(paths) for prefix, root in u.configitems(b'collections'): prefix = util.pconvert(prefix) for path in scmutil.walkrepos(root, followsym=True): repo = os.path.normpath(path) name = util.pconvert(repo) if name.startswith(prefix): name = name[len(prefix) :] repos.append((name.lstrip(b'/'), repo)) self.repos = repos self.ui = u self.gc_full_collect_rate = self.ui.configint( b'experimental', b'web.full-garbage-collection-rate' ) self.gc_full_collections_done = 0 encoding.encoding = self.ui.config(b'web', b'encoding') self.style = self.ui.config(b'web', b'style') self.templatepath = self.ui.config( b'web', b'templates', untrusted=False ) self.stripecount = self.ui.config(b'web', b'stripes') if self.stripecount: self.stripecount = int(self.stripecount) prefix = self.ui.config(b'web', b'prefix') if prefix.startswith(b'/'): prefix = prefix[1:] if prefix.endswith(b'/'): prefix = prefix[:-1] self.prefix = prefix self.lastrefresh = time.time() def run(self): if not encoding.environ.get(b'GATEWAY_INTERFACE', b'').startswith( b"CGI/1." ): raise RuntimeError( b"This function is only intended to be " b"called while running as a CGI script." ) wsgicgi.launch(self) def __call__(self, env, respond): baseurl = self.ui.config(b'web', b'baseurl') req = requestmod.parserequestfromenv(env, altbaseurl=baseurl) res = requestmod.wsgiresponse(req, respond) return self.run_wsgi(req, res) def run_wsgi(self, req, res): profile = self.ui.configbool(b'profiling', b'enabled') with profiling.profile(self.ui, enabled=profile): try: for r in self._runwsgi(req, res): yield r finally: # There are known cycles in localrepository that prevent # those objects (and tons of held references) from being # collected through normal refcounting. # In some cases, the resulting memory consumption can # be tamed by performing explicit garbage collections. # In presence of actual leaks or big long-lived caches, the # impact on performance of such collections can become a # problem, hence the rate shouldn't be set too low. # See "Collecting the oldest generation" in # https://devguide.python.org/garbage_collector # for more about such trade-offs. rate = self.gc_full_collect_rate # this is not thread safe, but the consequence (skipping # a garbage collection) is arguably better than risking # to have several threads perform a collection in parallel # (long useless wait on all threads). self.requests_count += 1 if rate > 0 and self.requests_count % rate == 0: gc.collect() self.gc_full_collections_done += 1 else: gc.collect(generation=1) def _runwsgi(self, req, res): try: self.refresh() csp, nonce = cspvalues(self.ui) if csp: res.headers[b'Content-Security-Policy'] = csp virtual = req.dispatchpath.strip(b'/') tmpl = self.templater(req, nonce) ctype = tmpl.render(b'mimetype', {b'encoding': encoding.encoding}) # Global defaults. These can be overridden by any handler. res.status = b'200 Script output follows' res.headers[b'Content-Type'] = ctype # a static file if virtual.startswith(b'static/') or b'static' in req.qsparams: if virtual.startswith(b'static/'): fname = virtual[7:] else: fname = req.qsparams[b'static'] static = self.ui.config(b"web", b"static", untrusted=False) staticfile(self.templatepath, static, fname, res) return res.sendresponse() # top-level index repos = dict(self.repos) if (not virtual or virtual == b'index') and virtual not in repos: return self.makeindex(req, res, tmpl) # nested indexes and hgwebs if virtual.endswith(b'/index') and virtual not in repos: subdir = virtual[: -len(b'index')] if any(r.startswith(subdir) for r in repos): return self.makeindex(req, res, tmpl, subdir) def _virtualdirs(): # Check the full virtual path, and each parent yield virtual for p in pathutil.finddirs(virtual): yield p for virtualrepo in _virtualdirs(): real = repos.get(virtualrepo) if real: # Re-parse the WSGI environment to take into account our # repository path component. uenv = req.rawenv if pycompat.ispy3: uenv = { k.decode('latin1'): v for k, v in pycompat.iteritems(uenv) } req = requestmod.parserequestfromenv( uenv, reponame=virtualrepo, altbaseurl=self.ui.config(b'web', b'baseurl'), # Reuse wrapped body file object otherwise state # tracking can get confused. bodyfh=req.bodyfh, ) try: # ensure caller gets private copy of ui repo = hg.repository(self.ui.copy(), real) return hgweb_mod.hgweb(repo).run_wsgi(req, res) except IOError as inst: msg = encoding.strtolocal(inst.strerror) raise ErrorResponse(HTTP_SERVER_ERROR, msg) except error.RepoError as inst: raise ErrorResponse(HTTP_SERVER_ERROR, bytes(inst)) # browse subdirectories subdir = virtual + b'/' if [r for r in repos if r.startswith(subdir)]: return self.makeindex(req, res, tmpl, subdir) # prefixes not found res.status = b'404 Not Found' res.setbodygen(tmpl.generate(b'notfound', {b'repo': virtual})) return res.sendresponse() except ErrorResponse as e: res.status = statusmessage(e.code, pycompat.bytestr(e)) res.setbodygen( tmpl.generate(b'error', {b'error': e.message or b''}) ) return res.sendresponse() finally: del tmpl def makeindex(self, req, res, tmpl, subdir=b""): self.refresh() sortable = [b"name", b"description", b"contact", b"lastchange"] sortcolumn, descending = None, False if b'sort' in req.qsparams: sortcolumn = req.qsparams[b'sort'] descending = sortcolumn.startswith(b'-') if descending: sortcolumn = sortcolumn[1:] if sortcolumn not in sortable: sortcolumn = b"" sort = [ ( b"sort_%s" % column, b"%s%s" % ( (not descending and column == sortcolumn) and b"-" or b"", column, ), ) for column in sortable ] self.refresh() entries = indexentries( self.ui, self.repos, req, self.stripecount, sortcolumn=sortcolumn, descending=descending, subdir=subdir, ) mapping = { b'entries': entries, b'subdir': subdir, b'pathdef': hgweb_mod.makebreadcrumb(b'/' + subdir, self.prefix), b'sortcolumn': sortcolumn, b'descending': descending, } mapping.update(sort) res.setbodygen(tmpl.generate(b'index', mapping)) return res.sendresponse() def templater(self, req, nonce): def config(*args, **kwargs): kwargs.setdefault('untrusted', True) return self.ui.config(*args, **kwargs) vars = {} styles, (style, mapfile, fp) = hgweb_mod.getstyle( req, config, self.templatepath ) if style == styles[0]: vars[b'style'] = style sessionvars = webutil.sessionvars(vars, b'?') logourl = config(b'web', b'logourl') logoimg = config(b'web', b'logoimg') staticurl = ( config(b'web', b'staticurl') or req.apppath.rstrip(b'/') + b'/static/' ) if not staticurl.endswith(b'/'): staticurl += b'/' defaults = { b"encoding": encoding.encoding, b"url": req.apppath + b'/', b"logourl": logourl, b"logoimg": logoimg, b"staticurl": staticurl, b"sessionvars": sessionvars, b"style": style, b"nonce": nonce, } templatekeyword = registrar.templatekeyword(defaults) @templatekeyword(b'motd', requires=()) def motd(context, mapping): if self.motd is not None: yield self.motd else: yield config(b'web', b'motd') return templater.templater.frommapfile( mapfile, fp=fp, defaults=defaults )