Create and store persistent unique ids for sessionStorage.

webkit/dom_storage/dom_storage_session.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_SESSION_H_
 #define WEBKIT_DOM_STORAGE_DOM_STORAGE_SESSION_H_
 #pragma once
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 
 namespace dom_storage {
 
 class DomStorageContext;
 
 // This refcounted class determines the lifetime of a session
 // storage namespace and provides an interface to Clone() an
 // existing session storage namespace. It may be used on any thread.
 // See class comments for DomStorageContext for a larger overview.
 class DomStorageSession
     : public base::RefCountedThreadSafe<DomStorageSession> {
  public:
+  // Constructs a |DomStorageSession| and allocates new IDs for it.
   explicit DomStorageSession(DomStorageContext* context);
+
+  // Constructs a |DomStorageSession| and assigns |persistent_namespace_id|
+  // to it. Allocates a new non-persistent ID.
+  DomStorageSession(DomStorageContext* context,
+                    const std::string& persistent_namespace_id);
+
   int64 namespace_id() const { return namespace_id_; }
+  const std::string& persistent_namespace_id() const {
+    return persistent_namespace_id_;
+  }
   DomStorageSession* Clone();
 
+  // Constructs a |DomStorageSession| by cloning
+  // |namespace_id_to_clone|. Allocates new IDs for it.
   static DomStorageSession* CloneFrom(DomStorageContext* context,
                                       int64 namepace_id_to_clone);
 
  private:
   friend class base::RefCountedThreadSafe<DomStorageSession>;
 
-  DomStorageSession(DomStorageContext* context, int64 namespace_id);
+  DomStorageSession(DomStorageContext* context,
+                    int64 namespace_id,
+                    const std::string& persistent_namespace_id);
   ~DomStorageSession();
 
   scoped_refptr<DomStorageContext> context_;
   int64 namespace_id_;
+  std::string persistent_namespace_id_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(DomStorageSession);
 };
 
 }  // namespace dom_storage
 
 #endif  // WEBKIT_DOM_STORAGE_DOM_STORAGE_SESSION_H_