Skeleton of the overall design for the database for Pver4

components/safe_browsing_db/v4_database_impl.h

Index: components/safe_browsing_db/v4_database_impl.h
diff --git a/components/safe_browsing_db/v4_database_impl.h b/components/safe_browsing_db/v4_database_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..150a05cd61d8c7ee9ba299d1333c70df1c911365
--- /dev/null
+++ b/components/safe_browsing_db/v4_database_impl.h
@@ -0,0 +1,49 @@
+// Copyright (c) 2016 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 COMPONENTS_SAFE_BROWSING_DB_V4_DATABASE_IMPL_H_
+#define COMPONENTS_SAFE_BROWSING_DB_V4_DATABASE_IMPL_H_
+
+#include "components/safe_browsing_db/v4_database.h"
+
+namespace safe_browsing {
+
+struct UpdateListIdentifier;
+class V4Store;
+
+typedef std::unique_ptr<
+    base::hash_map<UpdateListIdentifier, std::unique_ptr<V4Store>>>
+    StoreMap;
+
+// The on-disk databases are shared among all profiles, as it doesn't contain

[Nathan Parker, 2016/05/05 18:26:44]

nit: No need to duplicate the comment from the interface -- they'll likely get
out of sync any way.

Do you think you need the abstract interface + impl, or could you do with just
one class?  Simpler is better, as long as its sufficient for testing.  You could
still derive a mocked class from the concrete class, for testing.

[vakh (use Gerrit instead), 2016/05/06 00:23:15]

Done.

+// user-specific data. This object is not thread-safe, i.e. all its methods
+// should be used on the same thread that it was created on, unless specified
+// otherwise.
+class V4DatabaseImpl : public V4Database {
+ public:
+   // Stores a map of the stores it manages. Takes ownership of the map.
+   V4DatabaseImpl(
+     const scoped_refptr<base::SequencedTaskRunner>& db_task_runner,
+     StoreMap store_map);
+
+  ~V4DatabaseImpl() override;
+
+  // Initializes the database with the given filename.
+  void Init(const base::FilePath& filename) override;
+
+  // Deletes the current database and creates a new one.
+  bool ResetDatabase() override;
+
+ private:
+  // The factory used to instantiate a V4Database object.
+  // Useful for tests, so they can provide their own implementation of
+  // V4Database.
+  static V4DatabaseFactory* factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(V4DatabaseImpl);
+};
+
+}  // namespace safe_browsing
+
+#endif  // COMPONENTS_SAFE_BROWSING_DB_V4_DATABASE_IMPL_H_