Framing for a DOMStorage backend that does not depend on in-process-webkit.

webkit/dom_storage/dom_storage_map.h

+// Copyright (c) 2012 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 WEBKIT_DOM_STORAGE_DOM_STORAGE_MAP_H_
+#define WEBKIT_DOM_STORAGE_DOM_STORAGE_MAP_H_
+#pragma once
+
+#include <map>
+
+#include "base/memory/ref_counted.h"
+#include "base/nullable_string16.h"
+#include "base/string16.h"
+#include "webkit/dom_storage/dom_storage_types.h"
+
+class FilePath;
+class GURL;
+
+namespace dom_storage {
+
+// A wrapper around a std::map that adds refcounting and
+// imposes a limit on the total byte size of the keys/values.
+// See class comments for DomStorageContext for a larger overview.
+class DomStorageMap
+    : public base::RefCountedThreadSafe<DomStorageMap> {
+ public:
+  DomStorageMap();
+
+  unsigned Length();
+  NullableString16 Key(unsigned index);
+  NullableString16 GetItem(const string16& key);
+  bool SetItem(const string16& key, const string16& value,
+               NullableString16* old_value);
+  bool RemoveItem(const string16& key, string16* old_value);
+
+  void SwapValues(ValuesMap* map);
+  DomStorageMap* DeepCopy();
+
+ private:
+  friend class base::RefCountedThreadSafe<DomStorageMap>;
+  ~DomStorageMap();
+
+  ValuesMap values_;
+  // TODO(benm): track usage and enforce a quota limit.
+};
+
+}  // namespace dom_storage
+
+#endif  // WEBKIT_DOM_STORAGE_DOM_STORAGE_AREA_H_