Make RegistryControlledDomainService a static-function container class, rather than a Singleton

net/base/registry_controlled_domain.cc

-//* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// NB: Modelled after Mozilla's code (originally written by Pamela Greene,
+// later modified by others), but almost entirely rewritten for Chrome.
+//   (netwerk/dns/src/nsEffectiveTLDService.cpp)
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
  * http://www.mozilla.org/MPL/
  *
  * Software distributed under the License is distributed on an "AS IS" basis,
  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
@@ skipping 38 matching lines @@
 
 #include "effective_tld_names.cc"
 
 namespace net {
 
 namespace {
 
 const int kExceptionRule = 1;
 const int kWildcardRule = 2;
 
-RegistryControlledDomainService* test_instance_;

[wtc, 2011/10/27 22:44:09]

Is test_instance_ not used?

[Ryan Sleevi, 2011/10/27 22:48:04]

Not in the refactor, no. Previously it was used by GetInstance() - further
indicating that the Singleton<>-ness was simply related to testing.

+}  // namespace
 
-}  // namespace
+RegistryControlledDomainService::FindDomainPtr
+RegistryControlledDomainService::find_domain_function_ =
+    Perfect_Hash::FindDomain;
 
 // static
 std::string RegistryControlledDomainService::GetDomainAndRegistry(
     const GURL& gurl) {
   const url_parse::Component host =
       gurl.parsed_for_possibly_invalid_spec().host;
   if ((host.len <= 0) || gurl.HostIsIPAddress())
     return std::string();
   return GetDomainAndRegistryImpl(std::string(
       gurl.possibly_invalid_spec().data() + host.begin, host.len));
@@ skipping 34 matching lines @@
 // static
 size_t RegistryControlledDomainService::GetRegistryLength(
     const GURL& gurl,
     bool allow_unknown_registries) {
   const url_parse::Component host =
       gurl.parsed_for_possibly_invalid_spec().host;
   if (host.len <= 0)
     return std::string::npos;
   if (gurl.HostIsIPAddress())
     return 0;
-  return GetInstance()->GetRegistryLengthImpl(
+  return GetRegistryLengthImpl(
       std::string(gurl.possibly_invalid_spec().data() + host.begin, host.len),
       allow_unknown_registries);
 }
 
 // static
 size_t RegistryControlledDomainService::GetRegistryLength(
     const std::string& host,
     bool allow_unknown_registries) {
   url_canon::CanonHostInfo host_info;
   const std::string canon_host(CanonicalizeHost(host, &host_info));
   if (canon_host.empty())
     return std::string::npos;
   if (host_info.IsIPAddress())
     return 0;
-  return GetInstance()->GetRegistryLengthImpl(canon_host,
-                                              allow_unknown_registries);
-}
-
-// static
-RegistryControlledDomainService* RegistryControlledDomainService::GetInstance()
-{
-  if (test_instance_)
-    return test_instance_;
-
-  return Singleton<RegistryControlledDomainService>::get();
-}
-
-RegistryControlledDomainService::RegistryControlledDomainService()
-    : find_domain_function_(Perfect_Hash::FindDomain) {
-}
-
-// static
-RegistryControlledDomainService* RegistryControlledDomainService::SetInstance(
-    RegistryControlledDomainService* instance) {
-  RegistryControlledDomainService* old_instance = test_instance_;
-  test_instance_ = instance;
-  return old_instance;
+  return GetRegistryLengthImpl(canon_host, allow_unknown_registries);
 }
 
 // static
 void RegistryControlledDomainService::UseFindDomainFunction(
     FindDomainPtr function) {
-  RegistryControlledDomainService* instance = GetInstance();
-  instance->find_domain_function_ = function;
+  if (function) {
+    find_domain_function_ = function;
+  } else {
+    find_domain_function_ = Perfect_Hash::FindDomain;
+  }
 }
 
 // static
 std::string RegistryControlledDomainService::GetDomainAndRegistryImpl(
     const std::string& host) {
   DCHECK(!host.empty());
 
   // Find the length of the registry for this host.
-  const size_t registry_length =
-      GetInstance()->GetRegistryLengthImpl(host, true);
+  const size_t registry_length = GetRegistryLengthImpl(host, true);
   if ((registry_length == std::string::npos) || (registry_length == 0))
     return std::string();  // No registry.
   // The "2" in this next line is 1 for the dot, plus a 1-char minimum preceding
   // subcomponent length.
   DCHECK(host.length() >= 2);
   if (registry_length > (host.length() - 2)) {
     NOTREACHED() <<
         "Host does not have at least one subcomponent before registry!";
     return std::string();
   }
@@ skipping 80 matching lines @@
     next_dot = host.find('.', curr_start);
   }
 
   // No rule found in the registry.  curr_start now points to the first
   // character of the last subcomponent of the host, so if we allow unknown
   // registries, return the length of this subcomponent.
   return allow_unknown_registries ? (host.length() - curr_start) : 0;
 }
 
 }  // namespace net