def __call__(self, environ, start_response):
        g = config['pylons.g']
        http_host = environ.get('HTTP_HOST', 'localhost').lower()
        domain, s, port = http_host.partition(':')

        # remember the port
        try:
            environ['request_port'] = int(port)
        except ValueError:
            pass

        # localhost is exempt so paster run/shell will work
        # media_domain doesn't need special processing since it's just ads
        if domain == "localhost" or is_subdomain(domain, g.media_domain):
            return self.app(environ, start_response)

        # tell reddit_base to redirect to the appropriate subreddit for
        # a legacy CNAME
        if not is_subdomain(domain, g.domain):
            environ['legacy-cname'] = domain
            return self.app(environ, start_response)

        # figure out what subdomain we're on if any
        subdomains = domain[:-len(g.domain) - 1].split('.')
        extension_subdomains = dict(
            m="mobile",
            i="compact",
            api="api",
            rss="rss",
            xml="xml",
            json="json")

        sr_redirect = None
        for subdomain in subdomains[:]:
            if subdomain in g.reserved_subdomains:
                continue

            extension = extension_subdomains.get(subdomain)
            if extension:
                environ['reddit-domain-extension'] = extension
            elif self.lang_re.match(subdomain):
                environ['reddit-prefer-lang'] = subdomain
                environ['reddit-domain-prefix'] = subdomain
            else:
                sr_redirect = subdomain
                subdomains.remove(subdomain)

        # if there was a subreddit subdomain, redirect
        if sr_redirect and environ.get("FULLPATH"):
            if not subdomains and g.domain_prefix:
                subdomains.append(g.domain_prefix)
            subdomains.append(g.domain)
            redir = "%s/r/%s/%s" % ('.'.join(subdomains), sr_redirect,
                                    environ['FULLPATH'])
            redir = "http://" + redir.replace('//', '/')

            start_response("301 Moved Permanently", [("Location", redir)])
            return [""]

        return self.app(environ, start_response)

def _get_scrape_url(link):
    if not link.is_self:
        sr_name = link.subreddit_slow.name
        if not feature.is_enabled("imgur_gif_conversion", subreddit=sr_name):
            return link.url
        p = UrlParser(link.url)
        # If it's a gif link on imgur, replacing it with gifv should
        # give us the embedly friendly video url
        if is_subdomain(p.hostname, "imgur.com"):
            if p.path_extension().lower() == "gif":
                p.set_extension("gifv")
                return p.unparse()
        return link.url

    urls = extract_urls_from_markdown(link.selftext)
    second_choice = None
    for url in urls:
        p = UrlParser(url)
        if p.is_reddit_url():
            continue
        # If we don't find anything we like better, use the first image.
        if not second_choice:
            second_choice = url
        # This is an optimization for "proof images" in AMAs.
        if is_subdomain(p.netloc, 'imgur.com') or p.has_image_extension():
            return url

    return second_choice

    def __call__(self, environ, start_response):
        g = config["pylons.g"]
        http_host = environ.get("HTTP_HOST", "localhost").lower()
        domain, s, port = http_host.partition(":")

        # remember the port
        try:
            environ["request_port"] = int(port)
        except ValueError:
            pass

        # localhost is exempt so paster run/shell will work
        # media_domain doesn't need special processing since it's just ads
        if domain == "localhost" or is_subdomain(domain, g.media_domain):
            return self.app(environ, start_response)

        # tell reddit_base to redirect to the appropriate subreddit for
        # a legacy CNAME
        if not is_subdomain(domain, g.domain):
            environ["legacy-cname"] = domain
            return self.app(environ, start_response)

        # figure out what subdomain we're on if any
        subdomains = domain[: -len(g.domain) - 1].split(".")
        extension_subdomains = dict(m="mobile", i="compact", api="api", rss="rss", xml="xml", json="json")

        sr_redirect = None
        for subdomain in subdomains[:]:
            if subdomain in g.reserved_subdomains:
                continue

            extension = extension_subdomains.get(subdomain)
            if extension:
                environ["reddit-domain-extension"] = extension
            elif self.lang_re.match(subdomain):
                environ["reddit-prefer-lang"] = subdomain
                environ["reddit-domain-prefix"] = subdomain
            else:
                sr_redirect = subdomain
                subdomains.remove(subdomain)

        # if there was a subreddit subdomain, redirect
        if sr_redirect and environ.get("FULLPATH"):
            r = Response()
            if not subdomains and g.domain_prefix:
                subdomains.append(g.domain_prefix)
            subdomains.append(g.domain)
            redir = "%s/r/%s/%s" % (".".join(subdomains), sr_redirect, environ["FULLPATH"])
            redir = "http://" + redir.replace("//", "/")
            r.status_code = 301
            r.headers["location"] = redir
            r.content = ""
            return r(environ, start_response)

        return self.app(environ, start_response)

def js_config():
    config = {
        # is the user logged in?
        "logged": c.user_is_loggedin and c.user.name,
        # the subreddit's name (for posts)
        "post_site": c.site.name if not c.default_sr else "",
        # are we in an iframe?
        "cnameframe": bool(c.cname and not c.authorized_cname),
        # the user's voting hash
        "modhash": c.modhash or False,
        # the current rendering style
        "renderstyle": c.render_style,
        # current domain
        "cur_domain": get_domain(cname=c.frameless_cname, subreddit=False, no_www=True),
        # where do ajax requests go?
        "ajax_domain": get_domain(cname=c.authorized_cname, subreddit=False),
        "extension": c.extension,
        "https_endpoint": is_subdomain(request.host, g.domain) and g.https_endpoint,
        # debugging?
        "debug": g.debug,
        "vl": {},
        "sr": {},
        "status_msg": {
          "fetching": _("fetching title..."),
          "submitting": _("submitting..."),
          "loading": _("loading...")
        },
        "is_fake": isinstance(c.site, FakeSubreddit),
        "tracking_domain": g.tracking_domain,
        "adtracker_url": g.adtracker_url,
        "clicktracker_url": g.clicktracker_url,
        "uitracker_url": g.uitracker_url,
        "static_root": static(''),
    }
    return config

def is_trusted_origin(origin):
    try:
        origin = urlparse(origin)
    except ValueError:
        return False
    
    return any(is_subdomain(origin.hostname, domain) for domain in g.trusted_domains)

def allowed_media_preview_url(url):
    p = UrlParser(url)
    if p.has_static_image_extension():
        return True
    for allowed_domain in g.media_preview_domain_whitelist:
        if is_subdomain(p.hostname, allowed_domain):
            return True
    return False

def js_config(extra_config=None):
    logged = c.user_is_loggedin and c.user.name
    gold = bool(logged and c.user.gold)

    config = {
        # is the user logged in?
        "logged": logged,
        # the subreddit's name (for posts)
        "post_site": c.site.name if not c.default_sr else "",
        # the user's voting hash
        "modhash": c.modhash or False,
        # the current rendering style
        "renderstyle": c.render_style,

        # they're welcome to try to override this in the DOM because we just
        # disable the features server-side if applicable
        'store_visits': gold and c.user.pref_store_visits,

        # current domain
        "cur_domain": get_domain(cname=c.frameless_cname, subreddit=False, no_www=True),
        # where do ajax requests go?
        "ajax_domain": get_domain(cname=c.authorized_cname, subreddit=False),
        "extension": c.extension,
        "https_endpoint": is_subdomain(request.host, g.domain) and g.https_endpoint,
        # does the client only want to communicate over HTTPS?
        "https_forced": c.user.https_forced,
        # debugging?
        "debug": g.debug,
        "send_logs": g.live_config["frontend_logging"],
        "server_time": math.floor(time.time()),
        "status_msg": {
          "fetching": _("fetching title..."),
          "submitting": _("submitting..."),
          "loading": _("loading...")
        },
        "is_fake": isinstance(c.site, FakeSubreddit),
        "fetch_trackers_url": g.fetch_trackers_url,
        "adtracker_url": g.adtracker_url,
        "clicktracker_url": g.clicktracker_url,
        "uitracker_url": g.uitracker_url,
        "static_root": static(''),
        "over_18": bool(c.over18),
        "new_window": bool(c.user.pref_newwindow),
        "vote_hash": c.vote_hash,
        "gold": gold,
        "has_subscribed": logged and c.user.has_subscribed,
    }

    if g.uncompressedJS:
        config["uncompressedJS"] = True

    if extra_config:
        config.update(extra_config)

    hooks.get_hook("js_config").call(config=config)

    return config

 def OPTIONS_report_cache_poisoning(self):
     """Send CORS headers for cache poisoning reports."""
     if "Origin" not in request.headers:
         return
     origin = request.headers["Origin"]
     parsed_origin = UrlParser(origin)
     if not is_subdomain(parsed_origin.hostname, g.domain):
         return
     response.headers["Access-Control-Allow-Origin"] = origin
     response.headers["Access-Control-Allow-Methods"] = "POST"
     response.headers["Access-Control-Allow-Headers"] = \
         "Authorization, X-Loggit, "
     response.headers["Access-Control-Allow-Credentials"] = "false"
     response.headers['Access-Control-Expose-Headers'] = \
         self.COMMON_REDDIT_HEADERS

    def on_crawlable_domain(self):
        # This ensures we don't have the port included.
        requested_domain = utils.domain(request.host)

        # If someone CNAMEs myspammysite.com to reddit.com or something, we
        # don't want search engines to index that.
        if not utils.is_subdomain(requested_domain, g.domain):
            return False

        # Only allow the canonical desktop site and mobile subdomains, since
        # we have canonicalization set up appropriately for them.
        # Note: in development, DomainMiddleware needs to be temporarily
        # modified to not skip assignment of reddit-domain-extension on
        # localhost for this to work properly.
        return (requested_domain == g.domain or
                request.environ.get('reddit-domain-extension') in
                    ('mobile', 'compact'))

def _get_scrape_url(link):
    if not link.is_self:
        return link.url

    urls = extract_urls_from_markdown(link.selftext)
    second_choice = None
    for url in urls:
        p = UrlParser(url)
        if p.is_reddit_url():
            continue
        # If we don't find anything we like better, use the first image.
        if not second_choice:
            second_choice = url
        # This is an optimization for "proof images" in AMAs.
        if is_subdomain(p.netloc, 'imgur.com') or p.has_image_extension():
            return url

    return second_choice

def js_config(extra_config=None):
    config = {
        # is the user logged in?
        "logged": c.user_is_loggedin and c.user.name,
        # the subreddit's name (for posts)
        "post_site": c.site.name if not c.default_sr else "",
        # are we in an iframe?
        "cnameframe": bool(c.cname and not c.authorized_cname),
        # the user's voting hash
        "modhash": c.modhash or False,
        # the current rendering style
        "renderstyle": c.render_style,
        # current domain
        "cur_domain": get_domain(cname=c.frameless_cname, subreddit=False, no_www=True),
        # where do ajax requests go?
        "ajax_domain": get_domain(cname=c.authorized_cname, subreddit=False),
        "extension": c.extension,
        "https_endpoint": is_subdomain(request.host, g.domain) and g.https_endpoint,
        # debugging?
        "debug": g.debug,
        "send_logs": g.live_config["frontend_logging"],
        "server_time": math.floor(time.time()),
        "status_msg": {
          "fetching": _("fetching title..."),
          "submitting": _("submitting..."),
          "loading": _("loading...")
        },
        "is_fake": isinstance(c.site, FakeSubreddit),
        "fetch_trackers_url": g.fetch_trackers_url,
        "adtracker_url": g.adtracker_url,
        "clicktracker_url": g.clicktracker_url,
        "uitracker_url": g.uitracker_url,
        "static_root": static(''),
        "over_18": bool(c.over18),
        "vote_hash": c.vote_hash,
    }

    if extra_config:
        config.update(extra_config)

    hooks.get_hook("js_config").call(config=config)

    return config

def js_config(extra_config=None):
    logged = c.user_is_loggedin and c.user.name
    user_id = c.user_is_loggedin and c.user._id
    gold = bool(logged and c.user.gold)
    controller_name = request.environ['pylons.routes_dict']['controller']
    action_name = request.environ['pylons.routes_dict']['action']
    route_name = controller_name + '.' + action_name

    cache_policy = "loggedout_www"
    if c.user_is_loggedin:
        cache_policy = "loggedin_www_new"

    # Canary for detecting cache poisoning
    poisoning_canary = None
    poisoning_report_mac = None
    if logged:
        if "pc" in c.cookies and len(c.cookies["pc"].value) == 2:
            poisoning_canary = c.cookies["pc"].value
            poisoning_report_mac = make_poisoning_report_mac(
                poisoner_canary=poisoning_canary,
                poisoner_name=logged,
                poisoner_id=user_id,
                cache_policy=cache_policy,
                source="web",
                route_name=route_name,
            )

    mac = hmac.new(g.secrets["action_name"], route_name, hashlib.sha1)
    verification = mac.hexdigest()
    cur_subreddit = ""
    if isinstance(c.site, Subreddit) and not c.default_sr:
        cur_subreddit = c.site.name

    config = {
        # is the user logged in?
        "logged": logged,
        # logged in user's id
        "user_id": user_id,
        # the subreddit's name (for posts)
        "post_site": cur_subreddit,
        # the user's voting hash
        "modhash": c.modhash or False,
        # the current rendering style
        "renderstyle": c.render_style,

        # they're welcome to try to override this in the DOM because we just
        # disable the features server-side if applicable
        'store_visits': gold and c.user.pref_store_visits,

        # current domain
        "cur_domain": get_domain(cname=c.frameless_cname, subreddit=False, no_www=True),
        # where do ajax requests go?
        "ajax_domain": get_domain(cname=c.authorized_cname, subreddit=False),
        "stats_domain": g.stats_domain or '',
        "stats_sample_rate": g.stats_sample_rate or 0,
        "extension": c.extension,
        "https_endpoint": is_subdomain(request.host, g.domain) and g.https_endpoint,
        # does the client only want to communicate over HTTPS?
        "https_forced": c.user.https_forced,
        # debugging?
        "debug": g.debug,
        "poisoning_canary": poisoning_canary,
        "poisoning_report_mac": poisoning_report_mac,
        "cache_policy": cache_policy,
        "send_logs": g.live_config["frontend_logging"],
        "server_time": math.floor(time.time()),
        "status_msg": {
          "fetching": _("fetching title..."),
          "submitting": _("submitting..."),
          "loading": _("loading...")
        },
        "is_fake": isinstance(c.site, FakeSubreddit),
        "tracker_url": "",  # overridden below if configured
        "adtracker_url": g.adtracker_url,
        "clicktracker_url": g.clicktracker_url,
        "uitracker_url": g.uitracker_url,
        "eventtracker_url": g.eventtracker_url,
        "anon_eventtracker_url": g.anon_eventtracker_url,
        "static_root": static(''),
        "over_18": bool(c.over18),
        "new_window": bool(c.user.pref_newwindow),
        "mweb_blacklist_expressions": g.live_config['mweb_blacklist_expressions'],
        "vote_hash": c.vote_hash,
        "gold": gold,
        "has_subscribed": logged and c.user.has_subscribed,
        "is_sponsor": logged and c.user_is_sponsor,
        "pageInfo": {
          "verification": verification,
          "actionName": route_name,
        },
        "facebook_app_id": g.live_config["facebook_app_id"],
    }

    if g.tracker_url:
        config["tracker_url"] = tracking.get_pageview_pixel_url()

    if g.uncompressedJS:
        config["uncompressedJS"] = True

    if extra_config:
#.........这里部分代码省略.........

    def __call__(self, environ, start_response):
        g = config['pylons.g']
        http_host = environ.get('HTTP_HOST', 'localhost').lower()
        domain, s, port = http_host.partition(':')

        # remember the port
        try:
            environ['request_port'] = int(port)
        except ValueError:
            pass

        # localhost is exempt so paster run/shell will work
        # media_domain doesn't need special processing since it's just ads
        if domain == "localhost" or is_subdomain(domain, g.media_domain):
            return self.app(environ, start_response)

        # tell reddit_base to redirect to the appropriate subreddit for
        # a legacy CNAME
        if not is_subdomain(domain, g.domain):
            environ['legacy-cname'] = domain
            return self.app(environ, start_response)

        # How many characters to chop off the end of the hostname before
        # we start looking at subdomains
        ignored_suffix_len = len(g.domain)

        # figure out what subdomain we're on, if any
        subdomains = domain[:-ignored_suffix_len - 1].split('.')

        sr_redirect = None
        prefix_parts = []
        for subdomain in subdomains[:]:
            extension = g.extension_subdomains.get(subdomain)
            # These subdomains are reserved, don't treat them as SR
            # or language subdomains.
            if subdomain in g.reserved_subdomains:
                # Some subdomains are reserved, but also can't be mixed into
                # the domain prefix for various reasons (permalinks will be
                # broken, etc.)
                if subdomain in g.ignored_subdomains:
                    continue
                prefix_parts.append(subdomain)
            elif extension:
                environ['reddit-domain-extension'] = extension
            elif self.lang_re.match(subdomain):
                environ['reddit-prefer-lang'] = subdomain
            else:
                sr_redirect = subdomain
                subdomains.remove(subdomain)

        if 'reddit-prefer-lang' in environ:
            prefix_parts.insert(0, environ['reddit-prefer-lang'])
        if prefix_parts:
            environ['reddit-domain-prefix'] = '.'.join(prefix_parts)

        # if there was a subreddit subdomain, redirect
        if sr_redirect and environ.get("FULLPATH"):
            if not subdomains and g.domain_prefix:
                subdomains.append(g.domain_prefix)
            subdomains.append(g.domain)
            redir = "%s/r/%s/%s" % ('.'.join(subdomains),
                                    sr_redirect, environ['FULLPATH'])
            redir = "http://" + redir.replace('//', '/')

            start_response("301 Moved Permanently", [("Location", redir)])
            return [""]

        return self.app(environ, start_response)

    def __init__(self, space_compress=None, nav_menus=None, loginbox=True,
                 infotext='', infotext_class=None, content=None,
                 short_description='', title='',
                 robots=None, show_sidebar=True, show_chooser=False,
                 footer=True, srbar=True, page_classes=None, short_title=None,
                 show_wiki_actions=False, extra_js_config=None,
                 show_locationbar=False,
                 **context):
        Templated.__init__(self, **context)
        self.title = title
        self.short_title = short_title
        self.short_description = short_description
        self.robots = robots
        self.infotext = infotext
        self.extra_js_config = extra_js_config
        self.show_wiki_actions = show_wiki_actions
        self.loginbox = loginbox
        self.show_sidebar = show_sidebar
        self.space_compress = space_compress
        # instantiate a footer
        self.footer = RedditFooter() if footer else None
        self.debug_footer = DebugFooter()
        self.supplied_page_classes = page_classes or []

        #put the sort menus at the top
        self.nav_menu = MenuArea(menus = nav_menus) if nav_menus else None

        #add the infobar
        self.welcomebar = None
        self.newsletterbar = None
        self.locationbar = None
        self.infobar = None
        self.mobilewebredirectbar = None

        # generate a canonical link for google
        self.canonical_link = request.fullpath
        if c.render_style != "html":
            u = UrlParser(request.fullpath)
            u.set_extension("")
            u.hostname = g.domain
            if g.domain_prefix:
                u.hostname = "%s.%s" % (g.domain_prefix, u.hostname)
            self.canonical_link = u.unparse()
        # Generate a mobile link for Google.
        u = UrlParser(request.fullpath)
        u.switch_subdomain_by_extension('mobile')
        u.scheme = 'https'
        self.mobile_link = u.unparse()

        if self.show_infobar:
            if not infotext:
                if g.heavy_load_mode:
                    # heavy load mode message overrides read only
                    infotext = strings.heavy_load_msg
                elif g.read_only_mode:
                    infotext = strings.read_only_msg
                elif g.live_config.get("announcement_message"):
                    infotext = g.live_config["announcement_message"]

            if infotext:
                self.infobar = InfoBar(
                    message=infotext, extra_class=infotext_class)
            elif (isinstance(c.site, DomainSR) and
                    is_subdomain(c.site.domain, "imgur.com")):
                self.infobar = InfoBar(message=
                    _("imgur.com domain listings (including this one) are "
                      "currently disabled to speed up vote processing.")
                )
            elif isinstance(c.site, AllMinus) and not c.user.gold:
                self.infobar = InfoBar(message=strings.all_minus_gold_only,
                                       extra_class="gold")

            if not c.user_is_loggedin:
                self.welcomebar = WelcomeBar()
                if feature.is_enabled('newsletter') and getattr(self, "show_newsletterbar", True):
                    self.newsletterbar = NewsletterBar()

            if c.render_style == "compact":
                self.mobilewebredirectbar = MobileWebRedirectBar()

            show_locationbar &= not c.user.pref_hide_locationbar
            if (show_locationbar and c.used_localized_defaults and
                    (not c.user_is_loggedin or
                     not c.user.has_subscribed)):
                self.locationbar = LocationBar()

        self.srtopbar = None
        if srbar and not c.cname and not is_api():
            self.srtopbar = SubredditTopBar()

        panes = [content]

        if c.user_is_loggedin and not is_api() and not self.show_wiki_actions:
            # insert some form templates for js to use
            # TODO: move these to client side templates
            gold_link = GoldPayment("gift",
                                    "monthly",
                                    months=1,
                                    signed=False,
                                    recipient="",
#.........这里部分代码省略.........

def require_domain(required_domain):
    if not is_subdomain(request.host, required_domain):
        abort(ForbiddenError(errors.WRONG_DOMAIN))

def js_config(extra_config=None):
    logged = c.user_is_loggedin and c.user.name
    user_id = c.user_is_loggedin and c.user._id
    user_in_timeout = c.user_is_loggedin and c.user.in_timeout
    gold = bool(logged and c.user.gold)
    controller_name = request.environ['pylons.routes_dict']['controller']
    action_name = request.environ['pylons.routes_dict']['action']
    route_name = controller_name + '.' + action_name

    cache_policy = "loggedout_www"
    if c.user_is_loggedin:
        cache_policy = "loggedin_www_new"

    # Canary for detecting cache poisoning
    poisoning_canary = None
    poisoning_report_mac = None
    if logged:
        if "pc" in c.cookies and len(c.cookies["pc"].value) == 2:
            poisoning_canary = c.cookies["pc"].value
            poisoning_report_mac = make_poisoning_report_mac(
                poisoner_canary=poisoning_canary,
                poisoner_name=logged,
                poisoner_id=user_id,
                cache_policy=cache_policy,
                source="web",
                route_name=route_name,
            )

    mac = hmac.new(g.secrets["action_name"], route_name, hashlib.sha1)
    verification = mac.hexdigest()
    cur_subreddit = ""
    cur_sr_fullname = ""
    cur_listing = ""
    listing_over_18 = False
    pref_no_profanity = not logged or c.user.pref_no_profanity
    pref_media_preview = c.user.pref_media_preview

    if not feature.is_enabled("autoexpand_media_previews"):
        expando_preference = None
    elif pref_media_preview == "subreddit":
        expando_preference = "subreddit_default"
    elif pref_media_preview == "on":
        expando_preference = "auto_expand"
    else:
        expando_preference = "do_not_expand"

    pref_beta = c.user.pref_beta
    nsfw_media_acknowledged = logged and c.user.nsfw_media_acknowledged

    if isinstance(c.site, Subreddit) and not c.default_sr:
        cur_subreddit = c.site.name
        cur_sr_fullname = c.site._fullname
        cur_listing = cur_subreddit
        listing_over_18 = c.site.over_18
    elif isinstance(c.site, DefaultSR):
        cur_listing = "frontpage"
    elif isinstance(c.site, FakeSubreddit):
        cur_listing = c.site.name

    if g.debug:
        events_collector_url = g.events_collector_test_url
        events_collector_key = g.secrets['events_collector_test_js_key']
        events_collector_secret = g.secrets['events_collector_test_js_secret']
    else:
        events_collector_url = g.events_collector_url
        events_collector_key = g.secrets['events_collector_js_key']
        events_collector_secret = g.secrets['events_collector_js_secret']

    bp_currencyrates = hooks.get_hook("fetchcurrencyrates").call()[0]
    
    config = {
        # is the user logged in?
        "logged": logged,
        # logged in user's id
        "user_id": user_id,
        # is user in timeout?
        "user_in_timeout": user_in_timeout,
        # the subreddit's name (for posts)
        "post_site": cur_subreddit,
        "cur_site": cur_sr_fullname,
        "cur_listing": cur_listing,
        # the user's voting hash
        "modhash": c.modhash or False,
        # the current rendering style
        "renderstyle": c.render_style,

        # they're welcome to try to override this in the DOM because we just
        # disable the features server-side if applicable
        'store_visits': gold and c.user.pref_store_visits,

        # current domain
        "cur_domain": get_domain(subreddit=False, no_www=True),
        # where do ajax requests go?
        "ajax_domain": get_domain(subreddit=False),
        "stats_domain": g.stats_domain or '',
        "stats_sample_rate": g.stats_sample_rate or 0,
        "extension": c.extension,
        "https_endpoint": is_subdomain(request.host, g.domain) and g.https_endpoint,
        "media_domain": g.media_domain,
        # does the client only want to communicate over HTTPS?
#.........这里部分代码省略.........

#.........这里部分代码省略.........
    if feature.is_enabled("live_orangereds") and logged:
        user_websocket_url = websockets.make_url("/user/%s" % c.user._id36,
            max_age=24 * 60 * 60)
    else:
        user_websocket_url = None

    config = {
        # is the user logged in?
        "logged": logged,
        # logged in user's id
        "user_id": user_id,
        # is user in timeout?
        "user_in_timeout": user_in_timeout,
        # the subreddit's name (for posts)
        "post_site": cur_subreddit,
        "cur_site": cur_sr_fullname,
        "cur_listing": cur_listing,
        # the user's voting hash
        "modhash": c.modhash or False,
        # the current rendering style
        "renderstyle": c.render_style,

        # they're welcome to try to override this in the DOM because we just
        # disable the features server-side if applicable
        'store_visits': gold and c.user.pref_store_visits,

        # current domain
        "cur_domain": get_domain(subreddit=False, no_www=True),
        # where do ajax requests go?
        "ajax_domain": get_domain(subreddit=False),
        "stats_domain": g.stats_domain or '',
        "stats_sample_rate": g.stats_sample_rate or 0,
        "extension": c.extension,
        "https_endpoint": is_subdomain(request.host, g.domain) and g.https_endpoint,
        "media_domain": g.media_domain,
        # does the client only want to communicate over HTTPS?
        "https_forced": feature.is_enabled("force_https"),
        # debugging?
        "debug": g.debug,
        "poisoning_canary": poisoning_canary,
        "poisoning_report_mac": poisoning_report_mac,
        "cache_policy": cache_policy,
        "send_logs": g.live_config["frontend_logging"],
        "server_time": math.floor(time.time()),
        "status_msg": {
          "fetching": _("fetching title..."),
          "submitting": _("submitting..."),
          "loading": _("loading...")
        },
        "is_fake": isinstance(c.site, FakeSubreddit),
        "tracker_url": "",  # overridden below if configured
        "adtracker_url": g.adtracker_url,
        "clicktracker_url": g.clicktracker_url,
        "uitracker_url": g.uitracker_url,
        "eventtracker_url": g.eventtracker_url,
        "anon_eventtracker_url": g.anon_eventtracker_url,
        "events_collector_url": events_collector_url,
        "events_collector_key": events_collector_key,
        "events_collector_secret": events_collector_secret,
        "feature_screenview_events": feature.is_enabled('screenview_events'),
        "feature_outbound_beacons": feature.is_enabled('outbound_beacons'),
        "feature_scroll_events": feature.is_enabled('scroll_events'),
        "static_root": static(''),
        "over_18": bool(c.over18),
        "listing_over_18": listing_over_18,
        "expando_preference": expando_preference,

    def __call__(self, environ, start_response):
        g = config['pylons.g']
        http_host = environ.get('HTTP_HOST', 'localhost').lower()
        domain, s, port = http_host.partition(':')

        # remember the port
        try:
            environ['request_port'] = int(port)
        except ValueError:
            pass

        # localhost is exempt so paster run/shell will work
        # media_domain doesn't need special processing since it's just ads
        if domain == "localhost" or is_subdomain(domain, g.media_domain):
            return self.app(environ, start_response)

        # tell reddit_base to redirect to the appropriate subreddit for
        # a legacy CNAME
        if not is_subdomain(domain, g.domain):
            environ['legacy-cname'] = domain
            return self.app(environ, start_response)

        # How many characters to chop off the end of the hostname before
        # we start looking at subdomains
        ignored_suffix_len = len(g.domain)

        # OAuth is a bit of a special case. `foo.oauth.domain.com` should be
        # treated like `foo.domain.com` when generating links
        if g.oauth_domain and is_subdomain(domain, g.oauth_domain):
            ignored_suffix_len = len(g.oauth_domain)

        # figure out what subdomain we're on, if any
        subdomains = domain[:-ignored_suffix_len - 1].split('.')
        extension_subdomains = dict(m="mobile",
                                    i="compact",
                                    api="api",
                                    rss="rss",
                                    xml="xml",
                                    json="json")

        sr_redirect = None
        prefix_parts = []
        for subdomain in subdomains[:]:
            extension = extension_subdomains.get(subdomain)
            # These subdomains have special meanings, don't treat them as SR
            # or language subdomains.
            if subdomain in g.reserved_subdomains:
                if subdomain == g.domain_prefix:
                    continue
                prefix_parts.append(subdomain)
            elif extension:
                environ['reddit-domain-extension'] = extension
            elif self.lang_re.match(subdomain):
                environ['reddit-prefer-lang'] = subdomain
            else:
                sr_redirect = subdomain
                subdomains.remove(subdomain)

        if 'reddit-prefer-lang' in environ:
            prefix_parts.insert(0, environ['reddit-prefer-lang'])
        if prefix_parts:
            environ['reddit-domain-prefix'] = '.'.join(prefix_parts)

        # if there was a subreddit subdomain, redirect
        if sr_redirect and environ.get("FULLPATH"):
            if not subdomains and g.domain_prefix:
                subdomains.append(g.domain_prefix)
            subdomains.append(g.domain)
            redir = "%s/r/%s/%s" % ('.'.join(subdomains),
                                    sr_redirect, environ['FULLPATH'])
            redir = "http://" + redir.replace('//', '/')

            start_response("301 Moved Permanently", [("Location", redir)])
            return [""]

        return self.app(environ, start_response)

#.........这里部分代码省略.........
        if not promote.is_promoted(l) or c.user_is_sponsor:
            if title and title != l.title:
                l.title = title
                changed = not c.user_is_sponsor

            if kind == 'link' and url and url != l.url:
                l.url = url
                changed = not c.user_is_sponsor

        # only trips if t