Github user zuyu commented on a diff in the pull request:
https://github.com/apache/incubator-quickstep/pull/355#discussion_r189664042
--- Diff: storage/DataProviderThread.hpp ---
@@ -0,0 +1,103 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ **/
+
+#ifndef QUICKSTEP_STORAGE_DATA_PROVIDER_THREAD_HPP_
+#define QUICKSTEP_STORAGE_DATA_PROVIDER_THREAD_HPP_
+
+#include <cstddef>
+
+#include "query_execution/QueryExecutionTypedefs.hpp"
+#include "storage/StorageConfig.h"
+#include "threading/Thread.hpp"
+#include "utility/Macros.hpp"
+
+#include "tmb/native_net_client_message_bus.h"
+
+namespace quickstep {
+
+class CatalogDatabase;
+class CatalogRelation;
+class QueryProcessor;
+class StorageManager;
+
+/** \addtogroup Storage
+ * @{
+ */
+
+/**
+ * @brief A thread that provides access to query results (e.g. storage
blocks),
+ * to Quickstep clients.
--- End diff --
Could you please provide more info regarding this class, including which
class will own this class, and why it needs write permissions to both
`CatalogDatabase` and `QueryProcessor`? Thanks!
---
