1 // Copyright 2012 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef COMPONENTS_PREFS_OVERLAY_USER_PREF_STORE_H_
6 #define COMPONENTS_PREFS_OVERLAY_USER_PREF_STORE_H_
13 #include "base/memory/ref_counted.h"
14 #include "base/observer_list.h"
15 #include "base/strings/string_piece.h"
16 #include "base/values.h"
17 #include "components/prefs/persistent_pref_store.h"
18 #include "components/prefs/pref_name_set.h"
19 #include "components/prefs/pref_value_map.h"
20 #include "components/prefs/prefs_export.h"
22 // PersistentPrefStore that directs all write operations into an in-memory
23 // PrefValueMap. Read operations are first answered by the PrefValueMap.
24 // If the PrefValueMap does not contain a value for the requested key,
25 // the look-up is passed on to an underlying PersistentPrefStore
26 // |persistent_user_pref_store_|.
27 class COMPONENTS_PREFS_EXPORT OverlayUserPrefStore
28 : public PersistentPrefStore {
30 explicit OverlayUserPrefStore(PersistentPrefStore* persistent);
31 // The |ephemeral| store must already be initialized.
32 OverlayUserPrefStore(PersistentPrefStore* ephemeral,
33 PersistentPrefStore* persistent);
35 OverlayUserPrefStore(const OverlayUserPrefStore&) = delete;
36 OverlayUserPrefStore& operator=(const OverlayUserPrefStore&) = delete;
38 // Returns true if a value has been set for the |key| in this
39 // OverlayUserPrefStore, i.e. if it potentially overrides a value
40 // from the |persistent_user_pref_store_|.
41 virtual bool IsSetInOverlay(const std::string& key) const;
43 // Methods of PrefStore.
44 void AddObserver(PrefStore::Observer* observer) override;
45 void RemoveObserver(PrefStore::Observer* observer) override;
46 bool HasObservers() const override;
47 bool IsInitializationComplete() const override;
48 bool GetValue(base::StringPiece key,
49 const base::Value** result) const override;
50 base::Value::Dict GetValues() const override;
52 // Methods of PersistentPrefStore.
53 bool GetMutableValue(const std::string& key, base::Value** result) override;
54 void SetValue(const std::string& key,
56 uint32_t flags) override;
57 void SetValueSilently(const std::string& key,
59 uint32_t flags) override;
60 void RemoveValue(const std::string& key, uint32_t flags) override;
61 void RemoveValuesByPrefixSilently(const std::string& prefix) override;
62 bool ReadOnly() const override;
63 PrefReadError GetReadError() const override;
64 PrefReadError ReadPrefs() override;
65 void ReadPrefsAsync(ReadErrorDelegate* delegate) override;
66 void CommitPendingWrite(base::OnceClosure reply_callback,
67 base::OnceClosure synchronous_done_callback) override;
68 void SchedulePendingLossyWrites() override;
69 void ReportValueChanged(const std::string& key, uint32_t flags) override;
71 // Registers preferences that should be stored in the persistent preferences
72 // (|persistent_user_pref_store_|).
73 void RegisterPersistentPref(const std::string& key);
75 void OnStoreDeletionFromDisk() override;
78 ~OverlayUserPrefStore() override;
81 class ObserverAdapter;
83 void OnPrefValueChanged(bool ephemeral, const std::string& key);
84 void OnInitializationCompleted(bool ephemeral, bool succeeded);
86 // Returns true if |key| corresponds to a preference that shall be stored in
87 // persistent PrefStore.
88 bool ShallBeStoredInPersistent(base::StringPiece key) const;
90 base::ObserverList<PrefStore::Observer, true>::Unchecked observers_;
91 std::unique_ptr<ObserverAdapter> ephemeral_pref_store_observer_;
92 std::unique_ptr<ObserverAdapter> persistent_pref_store_observer_;
93 scoped_refptr<PersistentPrefStore> ephemeral_user_pref_store_;
94 scoped_refptr<PersistentPrefStore> persistent_user_pref_store_;
95 PrefNameSet persistent_names_set_;
98 #endif // COMPONENTS_PREFS_OVERLAY_USER_PREF_STORE_H_