// Copyright 2014 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. #ifndef COMPONENTS_PREFS_WRITEABLE_PREF_STORE_H_ #define COMPONENTS_PREFS_WRITEABLE_PREF_STORE_H_ #include #include #include #include #include #include "components/prefs/pref_store.h" namespace base { class Value; } // A pref store that can be written to as well as read from. class COMPONENTS_PREFS_EXPORT WriteablePrefStore : public PrefStore { public: // PrefWriteFlags can be used to change the way a pref will be written to // storage. enum PrefWriteFlags : uint32_t { // No flags are specified. DEFAULT_PREF_WRITE_FLAGS = 0, // This marks the pref as "lossy". There is no strict time guarantee on when // a lossy pref will be persisted to permanent storage when it is modified. LOSSY_PREF_WRITE_FLAG = 1 << 1 }; WriteablePrefStore() {} WriteablePrefStore(const WriteablePrefStore&) = delete; WriteablePrefStore& operator=(const WriteablePrefStore&) = delete; // Sets a |value| for |key| in the store. |value| must be non-NULL. |flags| is // a bitmask of PrefWriteFlags. virtual void SetValue(const std::string& key, std::unique_ptr value, uint32_t flags) = 0; // Removes the value for |key|. virtual void RemoveValue(const std::string& key, uint32_t flags) = 0; // Equivalent to PrefStore::GetValue but returns a mutable value. virtual bool GetMutableValue(const std::string& key, base::Value** result) = 0; // Triggers a value changed notification. This function or // ReportSubValuesChanged needs to be called if one retrieves a list or // dictionary with GetMutableValue and change its value. SetValue takes care // of notifications itself. Note that ReportValueChanged will trigger // notifications even if nothing has changed. |flags| is a bitmask of // PrefWriteFlags. virtual void ReportValueChanged(const std::string& key, uint32_t flags) = 0; // Triggers a value changed notification for |path_components| in the |key| // pref. This function or ReportValueChanged needs to be called if one // retrieves a list or dictionary with GetMutableValue and change its value. // SetValue takes care of notifications itself. Note that // ReportSubValuesChanged will trigger notifications even if nothing has // changed. |flags| is a bitmask of PrefWriteFlags. virtual void ReportSubValuesChanged( const std::string& key, std::set> path_components, uint32_t flags); // Same as SetValue, but doesn't generate notifications. This is used by // PrefService::GetMutableUserPref() in order to put empty entries // into the user pref store. Using SetValue is not an option since existing // tests rely on the number of notifications generated. |flags| is a bitmask // of PrefWriteFlags. virtual void SetValueSilently(const std::string& key, std::unique_ptr value, uint32_t flags) = 0; // Clears all the preferences which names start with |prefix| and doesn't // generate update notifications. virtual void RemoveValuesByPrefixSilently(const std::string& prefix) = 0; protected: ~WriteablePrefStore() override {} }; #endif // COMPONENTS_PREFS_WRITEABLE_PREF_STORE_H_