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

webkit/dom_storage/dom_storage_host.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_HOST_H_
+#define WEBKIT_DOM_STORAGE_DOM_STORAGE_HOST_H_
+#pragma once
+
+#include <map>
+
+#include "base/memory/ref_counted.h"
+#include "base/nullable_string16.h"
+#include "base/string16.h"
+
+class GURL;
+
+namespace dom_storage {
+
+class DOMStorageContext;
+class DOMStorageHost;
+class DOMStorageNamespace;
+class DOMStorageArea;
+
+// One instance is allocated in the main process for each client process.
+// Used by DOMStorageMessageFilter in Chrome and by SimpleDOMStorage in DRT.
+// This class is single threaded, and performs blocking file reads/writes,
+// so it shouldn't be used on chrome's IO thread.
+class DOMStorageHost {
+ public:
+  DOMStorageHost(DOMStorageContext* context);
+  ~DOMStorageHost();
+
+  int OpenStorageArea(int namespace_id, const GURL& origin);
+  void CloseStorageArea(int connection_id);
+
+  int GetAreaLength(int connection_id);
+  NullableString16 GetKey(int connection_id, int index);

[jsbell, 2012/01/24 19:37:25]

Nit: The naming here is slightly inconsistent - why is this not GetAreaKey()?
Presumably because GetAreaLength/ClearArea operate on the whole Area, vs methods
that operate on just keys/items. I'd kind of like to see "Area" in the other
method names, but not strongly.

+  NullableString16 GetItem(int connection_id, const string16& key);
+  bool SetItem(int connection_id, const string16& key,
+               const string16& value, const GURL& page_url,
+               NullableString16* old_value);
+  bool RemoveItem(int connection_id, const string16& key,
+                  const GURL& page_url,
+                  NullableString16* old_value);
+  bool ClearArea(int connection_id, const GURL& page_url);
+
+ private:
+  typedef std::map<int, scoped_refptr<DOMStorageArea> > AreaMap;
+
+  DOMStorageArea* GetOpenArea(int connection_id);
+
+  int last_connection_id_;
+  scoped_refptr<DOMStorageContext> context_;
+  AreaMap connections_;
+};
+
+}  // namespace dom_storage
+
+#endif  // WEBKIT_DOM_STORAGE_DOM_STORAGE_HOST_H_