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// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_PREFS_OVERLAY_USER_PREF_STORE_H_
#define COMPONENTS_PREFS_OVERLAY_USER_PREF_STORE_H_
#include <stdint.h>
#include <map>
#include <string>
#include "base/memory/ref_counted.h"
#include "base/observer_list.h"
#include "base/strings/string_piece.h"
#include "base/values.h"
#include "components/prefs/persistent_pref_store.h"
#include "components/prefs/pref_name_set.h"
#include "components/prefs/pref_value_map.h"
#include "components/prefs/prefs_export.h"
// PersistentPrefStore that directs all write operations into an in-memory
// PrefValueMap. Read operations are first answered by the PrefValueMap.
// If the PrefValueMap does not contain a value for the requested key,
// the look-up is passed on to an underlying PersistentPrefStore
// |persistent_user_pref_store_|.
class COMPONENTS_PREFS_EXPORT OverlayUserPrefStore
: public PersistentPrefStore {
public:
explicit OverlayUserPrefStore(PersistentPrefStore* persistent);
// The |ephemeral| store must already be initialized.
OverlayUserPrefStore(PersistentPrefStore* ephemeral,
PersistentPrefStore* persistent);
OverlayUserPrefStore(const OverlayUserPrefStore&) = delete;
OverlayUserPrefStore& operator=(const OverlayUserPrefStore&) = delete;
// Returns true if a value has been set for the |key| in this
// OverlayUserPrefStore, i.e. if it potentially overrides a value
// from the |persistent_user_pref_store_|.
virtual bool IsSetInOverlay(const std::string& key) const;
// Methods of PrefStore.
void AddObserver(PrefStore::Observer* observer) override;
void RemoveObserver(PrefStore::Observer* observer) override;
bool HasObservers() const override;
bool IsInitializationComplete() const override;
bool GetValue(base::StringPiece key,
const base::Value** result) const override;
base::Value::Dict GetValues() const override;
// Methods of PersistentPrefStore.
bool GetMutableValue(const std::string& key, base::Value** result) override;
void SetValue(const std::string& key,
base::Value value,
uint32_t flags) override;
void SetValueSilently(const std::string& key,
base::Value value,
uint32_t flags) override;
void RemoveValue(const std::string& key, uint32_t flags) override;
void RemoveValuesByPrefixSilently(const std::string& prefix) override;
bool ReadOnly() const override;
PrefReadError GetReadError() const override;
PrefReadError ReadPrefs() override;
void ReadPrefsAsync(ReadErrorDelegate* delegate) override;
void CommitPendingWrite(base::OnceClosure reply_callback,
base::OnceClosure synchronous_done_callback) override;
void SchedulePendingLossyWrites() override;
void ReportValueChanged(const std::string& key, uint32_t flags) override;
// Registers preferences that should be stored in the persistent preferences
// (|persistent_user_pref_store_|).
void RegisterPersistentPref(const std::string& key);
void OnStoreDeletionFromDisk() override;
protected:
~OverlayUserPrefStore() override;
private:
class ObserverAdapter;
void OnPrefValueChanged(bool ephemeral, const std::string& key);
void OnInitializationCompleted(bool ephemeral, bool succeeded);
// Returns true if |key| corresponds to a preference that shall be stored in
// persistent PrefStore.
bool ShallBeStoredInPersistent(base::StringPiece key) const;
base::ObserverList<PrefStore::Observer, true>::Unchecked observers_;
std::unique_ptr<ObserverAdapter> ephemeral_pref_store_observer_;
std::unique_ptr<ObserverAdapter> persistent_pref_store_observer_;
scoped_refptr<PersistentPrefStore> ephemeral_user_pref_store_;
scoped_refptr<PersistentPrefStore> persistent_user_pref_store_;
PrefNameSet persistent_names_set_;
};
#endif // COMPONENTS_PREFS_OVERLAY_USER_PREF_STORE_H_
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