chrome/browser/net/prediction_options.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/net/prediction_options.h"
   6
   7 #include "base/logging.h"
   8 #include "base/prefs/pref_service.h"
   9 #include "chrome/browser/profiles/profile_io_data.h"
  10 #include "chrome/common/pref_names.h"
  11 #include "components/pref_registry/pref_registry_syncable.h"
  12 #include "content/public/browser/browser_thread.h"
  13 #include "net/base/network_change_notifier.h"
  14
  15 namespace chrome_browser_net {
  16
  17 namespace {
  18
  19 // Since looking up preferences and current network connection are presumably
  20 // both cheap, we do not cache them here.
  21 bool CanPrefetchAndPrerender(int network_prediction_options) {
  22   switch (network_prediction_options) {
  23     case NETWORK_PREDICTION_ALWAYS:
  24       return true;
  25     case NETWORK_PREDICTION_NEVER:
  26       return false;
  27     default:
  28       DCHECK_EQ(NETWORK_PREDICTION_WIFI_ONLY, network_prediction_options);
  29       return !net::NetworkChangeNotifier::IsConnectionCellular(
  30                  net::NetworkChangeNotifier::GetConnectionType());
  31   }
  32 }
  33
  34 bool CanPreresolveAndPreconnect(int network_prediction_options) {
  35   // DNS preresolution and TCP preconnect are performed even on cellular
  36   // networks if the user setting is WIFI_ONLY.
  37   return network_prediction_options != NETWORK_PREDICTION_NEVER;
  38 }
  39
  40 }  // namespace
  41
  42 void RegisterPredictionOptionsProfilePrefs(
  43     user_prefs::PrefRegistrySyncable* registry) {
  44   registry->RegisterIntegerPref(
  45       prefs::kNetworkPredictionOptions,
  46       NETWORK_PREDICTION_DEFAULT,
  47       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
  48 }
  49
  50 bool CanPrefetchAndPrerenderIO(ProfileIOData* profile_io_data) {
  51   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
  52   DCHECK(profile_io_data);
  53   return CanPrefetchAndPrerender(
  54       profile_io_data->network_prediction_options()->GetValue());
  55 }
  56
  57 bool CanPrefetchAndPrerenderUI(PrefService* prefs) {
  58   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  59   DCHECK(prefs);
  60   return CanPrefetchAndPrerender(
  61       prefs->GetInteger(prefs::kNetworkPredictionOptions));
  62 }
  63
  64 bool CanPreresolveAndPreconnectIO(ProfileIOData* profile_io_data) {
  65   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
  66   DCHECK(profile_io_data);
  67   return CanPreresolveAndPreconnect(
  68       profile_io_data->network_prediction_options()->GetValue());
  69 }
  70
  71 bool CanPreresolveAndPreconnectUI(PrefService* prefs) {
  72   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  73   DCHECK(prefs);
  74   return CanPreresolveAndPreconnect(
  75       prefs->GetInteger(prefs::kNetworkPredictionOptions));
  76 }
  77
  78 }  // namespace chrome_browser_net