Persist sessionStorage on disk.

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"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/nullable_string16.h"
 #include "base/string16.h"
 #include "googleurl/src/gurl.h"
-#include "webkit/dom_storage/dom_storage_database.h"
+#include "webkit/dom_storage/dom_storage_database_adapter.h"
 #include "webkit/dom_storage/dom_storage_types.h"
 
 namespace dom_storage {
 
+class DomStorageDatabaseAdapter;
 class DomStorageMap;
 class DomStorageTaskRunner;
+class SessionStorageDatabase;
 
 // Container for a per-origin Map of key/value pairs potentially
 // 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.
   DomStorageArea(int64 namespace_id,
                  const GURL& origin,
                  const FilePath& directory,
                  DomStorageTaskRunner* task_runner);
 
+  // Session storage backed on disk.
+  DomStorageArea(int64 namespace_id,
+                 const GURL& origin,
+                 SessionStorageDatabase* session_storage_backing,
+                 DomStorageTaskRunner* task_runner);
+
+  // Local storage or session storage in memory.
+  DomStorageArea(int64 namespace_id,
+                 const GURL& origin,
+                 DomStorageTaskRunner* task_runner);
+
   const GURL& origin() const { return origin_; }
   int64 namespace_id() const { return namespace_id_; }
 
   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();
@@ skipping 21 matching lines @@
   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 class base::RefCountedThreadSafe<DomStorageArea>;
 
   struct CommitBatch {
+    // When committed, Commitbatch will first commit changed_values. If
+    // changed_values_after_deep_copy is non-empty, it will deep cpoy the map,
+    // and commit changed_values_after_deep_copy.

[michaeln, 2012/04/22 21:43:35]

see comments in the .cc file about simplifying this

[marja, 2012/05/11 12:18:32]

Done.

     bool clear_all_first;
     ValuesMap changed_values;
+    bool clear_all_after_deep_copy;
+    ValuesMap changed_values_after_deep_copy;
     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.
+  // disk on the commit sequence, and to call back on the primary task
+  // sequence when complete.
   CommitBatch* CreateCommitBatchIfNeeded();
   void OnCommitTimer();
   void CommitChanges();
   void OnCommitComplete();
 
   void ShutdownInCommitSequence();
 
   int64 namespace_id_;
   GURL origin_;
   FilePath directory_;
   scoped_refptr<DomStorageTaskRunner> task_runner_;
   scoped_refptr<DomStorageMap> map_;
-  scoped_ptr<DomStorageDatabase> backing_;
+  scoped_ptr<DomStorageDatabaseAdapter> backing_;
+  scoped_refptr<SessionStorageDatabase> session_storage_backing_;
   bool is_initial_import_done_;
   bool is_shutdown_;
+  bool is_shallow_copy_;

[michaeln, 2012/04/22 21:43:35]

not sure the is_shallow_copy_ data member is good addition, when the other
breaks instance breaks the link, this data member isn't updated...
map_->HasOneRef() works in all cases and we end up relying on that even with
this data member

[marja, 2012/05/11 12:18:32]

Gone.

   scoped_ptr<CommitBatch> commit_batch_;
   scoped_ptr<CommitBatch> in_flight_commit_batch_;
 };
 
 }  // namespace dom_storage
 
 #endif  // WEBKIT_DOM_STORAGE_DOM_STORAGE_AREA_H_