Create and store persistent unique ids for sessionStorage.

webkit/dom_storage/dom_storage_area.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_AREA_H_
 #define WEBKIT_DOM_STORAGE_DOM_STORAGE_AREA_H_
 #pragma once
 
 #include "base/file_path.h"
 #include "base/gtest_prod_util.h"
@@ skipping 13 matching lines @@
 // backed by storage on disk and lazily commits changes to disk.
 // See class comments for DomStorageContext for a larger overview.
 class DomStorageArea
     : public base::RefCountedThreadSafe<DomStorageArea> {
 
  public:
   static const FilePath::CharType kDatabaseFileExtension[];
   static FilePath DatabaseFileNameFromOrigin(const GURL& origin);
   static GURL OriginFromDatabaseFileName(const FilePath& file_name);
 
+  // Local storage. Backed on disk if directory is nonempty.
   DomStorageArea(int64 namespace_id,

[michaeln, 2012/06/14 22:53:48]

Can we remove the namespace_id param from this ctor since its only valid to call
with the kLocalStorageNamespaceId value?

[marja, 2012/06/15 09:17:42]

Done.

                  const GURL& origin,
                  const FilePath& directory,
                  DomStorageTaskRunner* task_runner);
 
+  // Session storage.
+  DomStorageArea(int64 namespace_id,
+                 const std::string& persistent_namespace_id,
+                 const GURL& origin,
+                 DomStorageTaskRunner* task_runner);
+
   const GURL& origin() const { return origin_; }
   int64 namespace_id() const { return namespace_id_; }
 
   // Writes a copy of the current set of values in the area to the |map|.
   void ExtractValues(ValuesMap* map);
 
   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);
   bool Clear();
 
-  DomStorageArea* ShallowCopy(int64 destination_namespace_id);
+  DomStorageArea* ShallowCopy(
+      int64 destination_namespace_id,
+      const std::string& destination_persistent_namespace_id);
 
   bool HasUncommittedChanges() const;
 
   // Similar to Clear() but more optimized for just deleting
   // without raising events.
   void DeleteOrigin();
 
   // Frees up memory when possible. Typically, this method returns
   // the object to its just constructed state, however if uncommitted
   // changes are pending, it does nothing.
   void PurgeMemory();
 
   // Schedules the commit of any unsaved changes and enters a
   // shutdown state such that the value getters and setters will
   // no longer do anything.
   void Shutdown();
 
  private:
   friend class DomStorageAreaTest;
   FRIEND_TEST_ALL_PREFIXES(DomStorageAreaTest, DomStorageAreaBasics);
   FRIEND_TEST_ALL_PREFIXES(DomStorageAreaTest, BackingDatabaseOpened);
   FRIEND_TEST_ALL_PREFIXES(DomStorageAreaTest, TestDatabaseFilePath);
   FRIEND_TEST_ALL_PREFIXES(DomStorageAreaTest, CommitTasks);
   FRIEND_TEST_ALL_PREFIXES(DomStorageAreaTest, CommitChangesAtShutdown);
   FRIEND_TEST_ALL_PREFIXES(DomStorageAreaTest, DeleteOrigin);
   FRIEND_TEST_ALL_PREFIXES(DomStorageAreaTest, PurgeMemory);
+  FRIEND_TEST_ALL_PREFIXES(DomStorageContextTest, PersistentIds);
   friend class base::RefCountedThreadSafe<DomStorageArea>;
 
   struct CommitBatch {
     bool clear_all_first;
     ValuesMap changed_values;
     CommitBatch();
     ~CommitBatch();
   };
 
   ~DomStorageArea();
 
   // If we haven't done so already and this is a local storage area,
   // will attempt to read any values for this origin currently
   // stored on disk.
   void InitialImportIfNeeded();
 
   // Post tasks to defer writing a batch of changed values to
   // disk on the commit sequence, and to call back on the primary
   // task sequence when complete.
   CommitBatch* CreateCommitBatchIfNeeded();
   void OnCommitTimer();
   void CommitChanges(const CommitBatch* commit_batch);
   void OnCommitComplete();
 
   void ShutdownInCommitSequence();
 
   int64 namespace_id_;
+  std::string persistent_namespace_id_;
   GURL origin_;
   FilePath directory_;
   scoped_refptr<DomStorageTaskRunner> task_runner_;
   scoped_refptr<DomStorageMap> map_;
   scoped_ptr<DomStorageDatabase> backing_;
   bool is_initial_import_done_;
   bool is_shutdown_;
   scoped_ptr<CommitBatch> commit_batch_;
   int commit_batches_in_flight_;
 };
 
 }  // namespace dom_storage
 
 #endif  // WEBKIT_DOM_STORAGE_DOM_STORAGE_AREA_H_