components/user_prefs/tracked/segregated_pref_store.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 "components/user_prefs/tracked/segregated_pref_store.h"
   6
   7 #include "base/logging.h"
   8 #include "base/stl_util.h"
   9 #include "base/values.h"
  10
  11 SegregatedPrefStore::AggregatingObserver::AggregatingObserver(
  12     SegregatedPrefStore* outer)
  13     : outer_(outer),
  14       failed_sub_initializations_(0),
  15       successful_sub_initializations_(0) {
  16 }
  17
  18 void SegregatedPrefStore::AggregatingObserver::OnPrefValueChanged(
  19     const std::string& key) {
  20   // There is no need to tell clients about changes if they have not yet been
  21   // told about initialization.
  22   if (failed_sub_initializations_ + successful_sub_initializations_ < 2)
  23     return;
  24
  25   FOR_EACH_OBSERVER(PrefStore::Observer, outer_->observers_,
  26                     OnPrefValueChanged(key));
  27 }
  28
  29 void SegregatedPrefStore::AggregatingObserver::OnInitializationCompleted(
  30     bool succeeded) {
  31   if (succeeded)
  32     ++successful_sub_initializations_;
  33   else
  34     ++failed_sub_initializations_;
  35
  36   DCHECK_LE(failed_sub_initializations_ + successful_sub_initializations_, 2);
  37
  38   if (failed_sub_initializations_ + successful_sub_initializations_ == 2) {
  39     if (successful_sub_initializations_ == 2 && outer_->read_error_delegate_) {
  40       PersistentPrefStore::PrefReadError read_error = outer_->GetReadError();
  41       if (read_error != PersistentPrefStore::PREF_READ_ERROR_NONE)
  42         outer_->read_error_delegate_->OnError(read_error);
  43     }
  44
  45     FOR_EACH_OBSERVER(
  46         PrefStore::Observer, outer_->observers_,
  47         OnInitializationCompleted(successful_sub_initializations_ == 2));
  48   }
  49 }
  50
  51 SegregatedPrefStore::SegregatedPrefStore(
  52     const scoped_refptr<PersistentPrefStore>& default_pref_store,
  53     const scoped_refptr<PersistentPrefStore>& selected_pref_store,
  54     const std::set<std::string>& selected_pref_names)
  55     : default_pref_store_(default_pref_store),
  56       selected_pref_store_(selected_pref_store),
  57       selected_preference_names_(selected_pref_names),
  58       aggregating_observer_(this) {
  59   default_pref_store_->AddObserver(&aggregating_observer_);
  60   selected_pref_store_->AddObserver(&aggregating_observer_);
  61 }
  62
  63 void SegregatedPrefStore::AddObserver(Observer* observer) {
  64   observers_.AddObserver(observer);
  65 }
  66
  67 void SegregatedPrefStore::RemoveObserver(Observer* observer) {
  68   observers_.RemoveObserver(observer);
  69 }
  70
  71 bool SegregatedPrefStore::HasObservers() const {
  72   return observers_.might_have_observers();
  73 }
  74
  75 bool SegregatedPrefStore::IsInitializationComplete() const {
  76   return default_pref_store_->IsInitializationComplete() &&
  77          selected_pref_store_->IsInitializationComplete();
  78 }
  79
  80 bool SegregatedPrefStore::GetValue(const std::string& key,
  81                                    const base::Value** result) const {
  82   return StoreForKey(key)->GetValue(key, result);
  83 }
  84
  85 void SegregatedPrefStore::SetValue(const std::string& key,
  86                                    scoped_ptr<base::Value> value,
  87                                    uint32 flags) {
  88   StoreForKey(key)->SetValue(key, value.Pass(), flags);
  89 }
  90
  91 void SegregatedPrefStore::RemoveValue(const std::string& key, uint32 flags) {
  92   StoreForKey(key)->RemoveValue(key, flags);
  93 }
  94
  95 bool SegregatedPrefStore::GetMutableValue(const std::string& key,
  96                                           base::Value** result) {
  97   return StoreForKey(key)->GetMutableValue(key, result);
  98 }
  99
 100 void SegregatedPrefStore::ReportValueChanged(const std::string& key,
 101                                              uint32 flags) {
 102   StoreForKey(key)->ReportValueChanged(key, flags);
 103 }
 104
 105 void SegregatedPrefStore::SetValueSilently(const std::string& key,
 106                                            scoped_ptr<base::Value> value,
 107                                            uint32 flags) {
 108   StoreForKey(key)->SetValueSilently(key, value.Pass(), flags);
 109 }
 110
 111 bool SegregatedPrefStore::ReadOnly() const {
 112   return selected_pref_store_->ReadOnly() || default_pref_store_->ReadOnly();
 113 }
 114
 115 PersistentPrefStore::PrefReadError SegregatedPrefStore::GetReadError() const {
 116   PersistentPrefStore::PrefReadError read_error =
 117       default_pref_store_->GetReadError();
 118   if (read_error == PersistentPrefStore::PREF_READ_ERROR_NONE) {
 119     read_error = selected_pref_store_->GetReadError();
 120     // Ignore NO_FILE from selected_pref_store_.
 121     if (read_error == PersistentPrefStore::PREF_READ_ERROR_NO_FILE)
 122       read_error = PersistentPrefStore::PREF_READ_ERROR_NONE;
 123   }
 124   return read_error;
 125 }
 126
 127 PersistentPrefStore::PrefReadError SegregatedPrefStore::ReadPrefs() {
 128   // Note: Both of these stores own PrefFilters which makes ReadPrefs
 129   // asynchronous. This is okay in this case as only the first call will be
 130   // truly asynchronous, the second call will then unblock the migration in
 131   // TrackedPreferencesMigrator and complete synchronously.
 132   default_pref_store_->ReadPrefs();
 133   PersistentPrefStore::PrefReadError selected_store_read_error =
 134       selected_pref_store_->ReadPrefs();
 135   DCHECK_NE(PersistentPrefStore::PREF_READ_ERROR_ASYNCHRONOUS_TASK_INCOMPLETE,
 136             selected_store_read_error);
 137
 138   return GetReadError();
 139 }
 140
 141 void SegregatedPrefStore::ReadPrefsAsync(ReadErrorDelegate* error_delegate) {
 142   read_error_delegate_.reset(error_delegate);
 143   default_pref_store_->ReadPrefsAsync(NULL);
 144   selected_pref_store_->ReadPrefsAsync(NULL);
 145 }
 146
 147 void SegregatedPrefStore::CommitPendingWrite() {
 148   default_pref_store_->CommitPendingWrite();
 149   selected_pref_store_->CommitPendingWrite();
 150 }
 151
 152 void SegregatedPrefStore::SchedulePendingLossyWrites() {
 153   default_pref_store_->SchedulePendingLossyWrites();
 154   selected_pref_store_->SchedulePendingLossyWrites();
 155 }
 156
 157 SegregatedPrefStore::~SegregatedPrefStore() {
 158   default_pref_store_->RemoveObserver(&aggregating_observer_);
 159   selected_pref_store_->RemoveObserver(&aggregating_observer_);
 160 }
 161
 162 PersistentPrefStore* SegregatedPrefStore::StoreForKey(const std::string& key) {
 163   return (ContainsKey(selected_preference_names_, key)
 164               ? selected_pref_store_
 165               : default_pref_store_).get();
 166 }
 167
 168 const PersistentPrefStore* SegregatedPrefStore::StoreForKey(
 169     const std::string& key) const {
 170   return (ContainsKey(selected_preference_names_, key)
 171               ? selected_pref_store_
 172               : default_pref_store_).get();
 173 }