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71 lines
2.5 KiB
C++
71 lines
2.5 KiB
C++
// Copyright 2014 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef BASE_PREFS_WRITEABLE_PREF_STORE_H_
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#define BASE_PREFS_WRITEABLE_PREF_STORE_H_
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#include <string>
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#include "base/basictypes.h"
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#include "base/memory/scoped_ptr.h"
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#include "base/prefs/pref_store.h"
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namespace base {
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class Value;
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}
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// A pref store that can be written to as well as read from.
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class BASE_PREFS_EXPORT WriteablePrefStore : public PrefStore {
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public:
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// PrefWriteFlags can be used to change the way a pref will be written to
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// storage.
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enum PrefWriteFlags : uint32 {
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// No flags are specified.
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DEFAULT_PREF_WRITE_FLAGS = 0,
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// This marks the pref as "lossy". There is no strict time guarantee on when
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// a lossy pref will be persisted to permanent storage when it is modified.
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LOSSY_PREF_WRITE_FLAG = 1 << 1
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};
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WriteablePrefStore() {}
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// Sets a |value| for |key| in the store. |value| must be non-NULL. |flags| is
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// a bitmask of PrefWriteFlags.
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virtual void SetValue(const std::string& key,
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scoped_ptr<base::Value> value,
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uint32 flags) = 0;
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// Removes the value for |key|.
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virtual void RemoveValue(const std::string& key, uint32 flags) = 0;
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// Equivalent to PrefStore::GetValue but returns a mutable value.
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virtual bool GetMutableValue(const std::string& key,
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base::Value** result) = 0;
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// Triggers a value changed notification. This function needs to be called
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// if one retrieves a list or dictionary with GetMutableValue and change its
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// value. SetValue takes care of notifications itself. Note that
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// ReportValueChanged will trigger notifications even if nothing has changed.
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// |flags| is a bitmask of PrefWriteFlags.
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virtual void ReportValueChanged(const std::string& key, uint32 flags) = 0;
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// Same as SetValue, but doesn't generate notifications. This is used by
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// PrefService::GetMutableUserPref() in order to put empty entries
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// into the user pref store. Using SetValue is not an option since existing
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// tests rely on the number of notifications generated. |flags| is a bitmask
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// of PrefWriteFlags.
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virtual void SetValueSilently(const std::string& key,
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scoped_ptr<base::Value> value,
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uint32 flags) = 0;
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protected:
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~WriteablePrefStore() override {}
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private:
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DISALLOW_COPY_AND_ASSIGN(WriteablePrefStore);
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};
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#endif // BASE_PREFS_WRITEABLE_PREF_STORE_H_
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