Revert of Move base/prefs to components/prefs

base/prefs/pref_value_store.cc

Index: base/prefs/pref_value_store.cc
diff --git a/base/prefs/pref_value_store.cc b/base/prefs/pref_value_store.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fe7cd67d08eb5970e36f50cf4c849ad1b842454e
--- /dev/null
+++ b/base/prefs/pref_value_store.cc
@@ -0,0 +1,290 @@
+// Copyright (c) 2012 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.
+
+#include "base/prefs/pref_value_store.h"
+
+#include <stddef.h>
+
+#include "base/logging.h"
+#include "base/prefs/pref_notifier.h"
+#include "base/prefs/pref_observer.h"
+
+PrefValueStore::PrefStoreKeeper::PrefStoreKeeper()
+    : pref_value_store_(NULL),
+      type_(PrefValueStore::INVALID_STORE) {
+}
+
+PrefValueStore::PrefStoreKeeper::~PrefStoreKeeper() {
+  if (pref_store_.get()) {
+    pref_store_->RemoveObserver(this);
+    pref_store_ = NULL;
+  }
+  pref_value_store_ = NULL;
+}
+
+void PrefValueStore::PrefStoreKeeper::Initialize(
+    PrefValueStore* store,
+    PrefStore* pref_store,
+    PrefValueStore::PrefStoreType type) {
+  if (pref_store_.get()) {
+    pref_store_->RemoveObserver(this);
+    DCHECK(!pref_store_->HasObservers());
+  }
+  type_ = type;
+  pref_value_store_ = store;
+  pref_store_ = pref_store;
+  if (pref_store_.get())
+    pref_store_->AddObserver(this);
+}
+
+void PrefValueStore::PrefStoreKeeper::OnPrefValueChanged(
+    const std::string& key) {
+  pref_value_store_->OnPrefValueChanged(type_, key);
+}
+
+void PrefValueStore::PrefStoreKeeper::OnInitializationCompleted(
+    bool succeeded) {
+  pref_value_store_->OnInitializationCompleted(type_, succeeded);
+}
+
+PrefValueStore::PrefValueStore(PrefStore* managed_prefs,
+                               PrefStore* supervised_user_prefs,
+                               PrefStore* extension_prefs,
+                               PrefStore* command_line_prefs,
+                               PrefStore* user_prefs,
+                               PrefStore* recommended_prefs,
+                               PrefStore* default_prefs,
+                               PrefNotifier* pref_notifier)
+    : pref_notifier_(pref_notifier),
+      initialization_failed_(false) {
+  InitPrefStore(MANAGED_STORE, managed_prefs);
+  InitPrefStore(SUPERVISED_USER_STORE, supervised_user_prefs);
+  InitPrefStore(EXTENSION_STORE, extension_prefs);
+  InitPrefStore(COMMAND_LINE_STORE, command_line_prefs);
+  InitPrefStore(USER_STORE, user_prefs);
+  InitPrefStore(RECOMMENDED_STORE, recommended_prefs);
+  InitPrefStore(DEFAULT_STORE, default_prefs);
+
+  CheckInitializationCompleted();
+}
+
+PrefValueStore::~PrefValueStore() {}
+
+PrefValueStore* PrefValueStore::CloneAndSpecialize(
+    PrefStore* managed_prefs,
+    PrefStore* supervised_user_prefs,
+    PrefStore* extension_prefs,
+    PrefStore* command_line_prefs,
+    PrefStore* user_prefs,
+    PrefStore* recommended_prefs,
+    PrefStore* default_prefs,
+    PrefNotifier* pref_notifier) {
+  DCHECK(pref_notifier);
+  if (!managed_prefs)
+    managed_prefs = GetPrefStore(MANAGED_STORE);
+  if (!supervised_user_prefs)
+    supervised_user_prefs = GetPrefStore(SUPERVISED_USER_STORE);
+  if (!extension_prefs)
+    extension_prefs = GetPrefStore(EXTENSION_STORE);
+  if (!command_line_prefs)
+    command_line_prefs = GetPrefStore(COMMAND_LINE_STORE);
+  if (!user_prefs)
+    user_prefs = GetPrefStore(USER_STORE);
+  if (!recommended_prefs)
+    recommended_prefs = GetPrefStore(RECOMMENDED_STORE);
+  if (!default_prefs)
+    default_prefs = GetPrefStore(DEFAULT_STORE);
+
+  return new PrefValueStore(
+      managed_prefs, supervised_user_prefs, extension_prefs, command_line_prefs,
+      user_prefs, recommended_prefs, default_prefs, pref_notifier);
+}
+
+void PrefValueStore::set_callback(const PrefChangedCallback& callback) {
+  pref_changed_callback_ = callback;
+}
+
+bool PrefValueStore::GetValue(const std::string& name,
+                              base::Value::Type type,
+                              const base::Value** out_value) const {
+  // Check the |PrefStore|s in order of their priority from highest to lowest,
+  // looking for the first preference value with the given |name| and |type|.
+  for (size_t i = 0; i <= PREF_STORE_TYPE_MAX; ++i) {
+    if (GetValueFromStoreWithType(name, type, static_cast<PrefStoreType>(i),
+                                  out_value))
+      return true;
+  }
+  return false;
+}
+
+bool PrefValueStore::GetRecommendedValue(const std::string& name,
+                                         base::Value::Type type,
+                                         const base::Value** out_value) const {
+  return GetValueFromStoreWithType(name, type, RECOMMENDED_STORE, out_value);
+}
+
+void PrefValueStore::NotifyPrefChanged(
+    const std::string& path,
+    PrefValueStore::PrefStoreType new_store) {
+  DCHECK(new_store != INVALID_STORE);
+  // A notification is sent when the pref value in any store changes. If this
+  // store is currently being overridden by a higher-priority store, the
+  // effective value of the pref will not have changed.
+  pref_notifier_->OnPreferenceChanged(path);
+  if (!pref_changed_callback_.is_null())
+    pref_changed_callback_.Run(path);
+}
+
+bool PrefValueStore::PrefValueInManagedStore(const std::string& name) const {
+  return PrefValueInStore(name, MANAGED_STORE);
+}
+
+bool PrefValueStore::PrefValueInSupervisedStore(const std::string& name) const {
+  return PrefValueInStore(name, SUPERVISED_USER_STORE);
+}
+
+bool PrefValueStore::PrefValueInExtensionStore(const std::string& name) const {
+  return PrefValueInStore(name, EXTENSION_STORE);
+}
+
+bool PrefValueStore::PrefValueInUserStore(const std::string& name) const {
+  return PrefValueInStore(name, USER_STORE);
+}
+
+bool PrefValueStore::PrefValueFromExtensionStore(
+    const std::string& name) const {
+  return ControllingPrefStoreForPref(name) == EXTENSION_STORE;
+}
+
+bool PrefValueStore::PrefValueFromUserStore(const std::string& name) const {
+  return ControllingPrefStoreForPref(name) == USER_STORE;
+}
+
+bool PrefValueStore::PrefValueFromRecommendedStore(
+    const std::string& name) const {
+  return ControllingPrefStoreForPref(name) == RECOMMENDED_STORE;
+}
+
+bool PrefValueStore::PrefValueFromDefaultStore(const std::string& name) const {
+  return ControllingPrefStoreForPref(name) == DEFAULT_STORE;
+}
+
+bool PrefValueStore::PrefValueUserModifiable(const std::string& name) const {
+  PrefStoreType effective_store = ControllingPrefStoreForPref(name);
+  return effective_store >= USER_STORE ||
+         effective_store == INVALID_STORE;
+}
+
+bool PrefValueStore::PrefValueExtensionModifiable(
+    const std::string& name) const {
+  PrefStoreType effective_store = ControllingPrefStoreForPref(name);
+  return effective_store >= EXTENSION_STORE ||
+         effective_store == INVALID_STORE;
+}
+
+void PrefValueStore::UpdateCommandLinePrefStore(PrefStore* command_line_prefs) {
+  InitPrefStore(COMMAND_LINE_STORE, command_line_prefs);
+}
+
+bool PrefValueStore::PrefValueInStore(
+    const std::string& name,
+    PrefValueStore::PrefStoreType store) const {
+  // Declare a temp Value* and call GetValueFromStore,
+  // ignoring the output value.
+  const base::Value* tmp_value = NULL;
+  return GetValueFromStore(name, store, &tmp_value);
+}
+
+bool PrefValueStore::PrefValueInStoreRange(
+    const std::string& name,
+    PrefValueStore::PrefStoreType first_checked_store,
+    PrefValueStore::PrefStoreType last_checked_store) const {
+  if (first_checked_store > last_checked_store) {
+    NOTREACHED();
+    return false;
+  }
+
+  for (size_t i = first_checked_store;
+       i <= static_cast<size_t>(last_checked_store); ++i) {
+    if (PrefValueInStore(name, static_cast<PrefStoreType>(i)))
+      return true;
+  }
+  return false;
+}
+
+PrefValueStore::PrefStoreType PrefValueStore::ControllingPrefStoreForPref(
+    const std::string& name) const {
+  for (size_t i = 0; i <= PREF_STORE_TYPE_MAX; ++i) {
+    if (PrefValueInStore(name, static_cast<PrefStoreType>(i)))
+      return static_cast<PrefStoreType>(i);
+  }
+  return INVALID_STORE;
+}
+
+bool PrefValueStore::GetValueFromStore(const std::string& name,
+                                       PrefValueStore::PrefStoreType store_type,
+                                       const base::Value** out_value) const {
+  // Only return true if we find a value and it is the correct type, so stale
+  // values with the incorrect type will be ignored.
+  const PrefStore* store = GetPrefStore(static_cast<PrefStoreType>(store_type));
+  if (store && store->GetValue(name, out_value))
+    return true;
+
+  // No valid value found for the given preference name: set the return value
+  // to false.
+  *out_value = NULL;
+  return false;
+}
+
+bool PrefValueStore::GetValueFromStoreWithType(
+    const std::string& name,
+    base::Value::Type type,
+    PrefStoreType store,
+    const base::Value** out_value) const {
+  if (GetValueFromStore(name, store, out_value)) {
+    if ((*out_value)->IsType(type))
+      return true;
+
+    LOG(WARNING) << "Expected type for " << name << " is " << type
+                 << " but got " << (*out_value)->GetType()
+                 << " in store " << store;
+  }
+
+  *out_value = NULL;
+  return false;
+}
+
+void PrefValueStore::OnPrefValueChanged(PrefValueStore::PrefStoreType type,
+                                        const std::string& key) {
+  NotifyPrefChanged(key, type);
+}
+
+void PrefValueStore::OnInitializationCompleted(
+    PrefValueStore::PrefStoreType type, bool succeeded) {
+  if (initialization_failed_)
+    return;
+  if (!succeeded) {
+    initialization_failed_ = true;
+    pref_notifier_->OnInitializationCompleted(false);
+    return;
+  }
+  CheckInitializationCompleted();
+}
+
+void PrefValueStore::InitPrefStore(PrefValueStore::PrefStoreType type,
+                                   PrefStore* pref_store) {
+  pref_stores_[type].Initialize(this, pref_store, type);
+}
+
+void PrefValueStore::CheckInitializationCompleted() {
+  if (initialization_failed_)
+    return;
+  for (size_t i = 0; i <= PREF_STORE_TYPE_MAX; ++i) {
+    scoped_refptr<PrefStore> store =
+        GetPrefStore(static_cast<PrefStoreType>(i));
+    if (store.get() && !store->IsInitializationComplete())
+      return;
+  }
+  pref_notifier_->OnInitializationCompleted(true);
+}