Roll src/third_party/WebKit 3b1337e:6074f0e (svn 199892:199893)
[chromium-blink-merge.git] / base / prefs / persistent_pref_store.h
blob89c7a71961c8a4943f3d6749f34d5ea11fcea20c
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.
5 #ifndef BASE_PREFS_PERSISTENT_PREF_STORE_H_
6 #define BASE_PREFS_PERSISTENT_PREF_STORE_H_
8 #include <string>
10 #include "base/prefs/base_prefs_export.h"
11 #include "base/prefs/writeable_pref_store.h"
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 WriteablePrefStore {
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 explicit values of the enums as it will change the
21 // server's meaning of the histogram.
22 enum PrefReadError {
23 PREF_READ_ERROR_NONE = 0,
24 PREF_READ_ERROR_JSON_PARSE = 1,
25 PREF_READ_ERROR_JSON_TYPE = 2,
26 PREF_READ_ERROR_ACCESS_DENIED = 3,
27 PREF_READ_ERROR_FILE_OTHER = 4,
28 PREF_READ_ERROR_FILE_LOCKED = 5,
29 PREF_READ_ERROR_NO_FILE = 6,
30 PREF_READ_ERROR_JSON_REPEAT = 7,
31 // PREF_READ_ERROR_OTHER = 8, // Deprecated.
32 PREF_READ_ERROR_FILE_NOT_SPECIFIED = 9,
33 // Indicates that ReadPrefs() couldn't complete synchronously and is waiting
34 // for an asynchronous task to complete first.
35 PREF_READ_ERROR_ASYNCHRONOUS_TASK_INCOMPLETE = 10,
36 PREF_READ_ERROR_MAX_ENUM
39 class ReadErrorDelegate {
40 public:
41 virtual ~ReadErrorDelegate() {}
43 virtual void OnError(PrefReadError error) = 0;
46 // Whether the store is in a pseudo-read-only mode where changes are not
47 // actually persisted to disk. This happens in some cases when there are
48 // read errors during startup.
49 virtual bool ReadOnly() const = 0;
51 // Gets the read error. Only valid if IsInitializationComplete() returns true.
52 virtual PrefReadError GetReadError() const = 0;
54 // Reads the preferences from disk. Notifies observers via
55 // "PrefStore::OnInitializationCompleted" when done.
56 virtual PrefReadError ReadPrefs() = 0;
58 // Reads the preferences from disk asynchronously. Notifies observers via
59 // "PrefStore::OnInitializationCompleted" when done. Also it fires
60 // |error_delegate| if it is not NULL and reading error has occurred.
61 // Owns |error_delegate|.
62 virtual void ReadPrefsAsync(ReadErrorDelegate* error_delegate) = 0;
64 // Lands any pending writes to disk.
65 virtual void CommitPendingWrite() = 0;
67 // Schedule a write if there is any lossy data pending. Unlike
68 // CommitPendingWrite() this does not immediately sync to disk, instead it
69 // triggers an eventual write if there is lossy data pending and if there
70 // isn't one scheduled already.
71 virtual void SchedulePendingLossyWrites() = 0;
73 protected:
74 ~PersistentPrefStore() override {}
77 #endif // BASE_PREFS_PERSISTENT_PREF_STORE_H_