1 // Copyright (c) 2012 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 #ifndef BASE_PREFS_PERSISTENT_PREF_STORE_H_ 6 #define BASE_PREFS_PERSISTENT_PREF_STORE_H_ 7 8 #include <string> 9 10 #include "base/prefs/base_prefs_export.h" 11 #include "base/prefs/pref_store.h" 12 13 // This interface is complementary to the PrefStore interface, declaring 14 // additional functionality that adds support for setting values and persisting 15 // the data to some backing store. 16 class BASE_PREFS_EXPORT PersistentPrefStore : public PrefStore { 17 public: 18 // Unique integer code for each type of error so we can report them 19 // distinctly in a histogram. 20 // NOTE: Don't change the order here as it will change the server's meaning 21 // of the histogram. 22 enum PrefReadError { 23 PREF_READ_ERROR_NONE = 0, 24 PREF_READ_ERROR_JSON_PARSE, 25 PREF_READ_ERROR_JSON_TYPE, 26 PREF_READ_ERROR_ACCESS_DENIED, 27 PREF_READ_ERROR_FILE_OTHER, 28 PREF_READ_ERROR_FILE_LOCKED, 29 PREF_READ_ERROR_NO_FILE, 30 PREF_READ_ERROR_JSON_REPEAT, 31 PREF_READ_ERROR_OTHER, 32 PREF_READ_ERROR_FILE_NOT_SPECIFIED, 33 PREF_READ_ERROR_MAX_ENUM 34 }; 35 36 class ReadErrorDelegate { 37 public: 38 virtual ~ReadErrorDelegate() {} 39 40 virtual void OnError(PrefReadError error) = 0; 41 }; 42 43 // Equivalent to PrefStore::GetValue but returns a mutable value. 44 virtual bool GetMutableValue(const std::string& key, 45 base::Value** result) = 0; 46 47 // Triggers a value changed notification. This function needs to be called 48 // if one retrieves a list or dictionary with GetMutableValue and change its 49 // value. SetValue takes care of notifications itself. Note that 50 // ReportValueChanged will trigger notifications even if nothing has changed. 51 virtual void ReportValueChanged(const std::string& key) = 0; 52 53 // Sets a |value| for |key| in the store. Assumes ownership of |value|, which 54 // must be non-NULL. 55 virtual void SetValue(const std::string& key, base::Value* value) = 0; 56 57 // Same as SetValue, but doesn't generate notifications. This is used by 58 // PrefService::GetMutableUserPref() in order to put empty entries 59 // into the user pref store. Using SetValue is not an option since existing 60 // tests rely on the number of notifications generated. 61 virtual void SetValueSilently(const std::string& key, base::Value* value) = 0; 62 63 // Removes the value for |key|. 64 virtual void RemoveValue(const std::string& key) = 0; 65 66 // Marks that the |key| with empty ListValue/DictionaryValue needs to be 67 // persisted. 68 virtual void MarkNeedsEmptyValue(const std::string& key) = 0; 69 70 // Whether the store is in a pseudo-read-only mode where changes are not 71 // actually persisted to disk. This happens in some cases when there are 72 // read errors during startup. 73 virtual bool ReadOnly() const = 0; 74 75 // Gets the read error. Only valid if IsInitializationComplete() returns true. 76 virtual PrefReadError GetReadError() const = 0; 77 78 // Reads the preferences from disk. Notifies observers via 79 // "PrefStore::OnInitializationCompleted" when done. 80 virtual PrefReadError ReadPrefs() = 0; 81 82 // Reads the preferences from disk asynchronously. Notifies observers via 83 // "PrefStore::OnInitializationCompleted" when done. Also it fires 84 // |error_delegate| if it is not NULL and reading error has occurred. 85 // Owns |error_delegate|. 86 virtual void ReadPrefsAsync(ReadErrorDelegate* error_delegate) = 0; 87 88 // Lands any pending writes to disk. 89 virtual void CommitPendingWrite() = 0; 90 91 protected: 92 virtual ~PersistentPrefStore() {} 93 }; 94 95 #endif // BASE_PREFS_PERSISTENT_PREF_STORE_H_ 96
