Refactored storage service out of client service interface.

include/wsrep/storage_service.hpp

@@ -0,0 +1,75 @@
+//
+// Copyright (C) 2018 Codership Oy <info@codership.com>
+//
+
+/** @file storage_service.hpp
+ *
+ * Abstract interface which defines required access to DBMS storage
+ * service. The service is used for storing streaming replication
+ * write set fragments into stable storage. The interface is used
+ * from locally processing transaction context only. Corresponding
+ * operations for high priority processing can be found from
+ * wsrep::high_priority_service interface.
+ */
+#ifndef WSREP_STORAGE_SERVICE_HPP
+#define WSREP_STORAGE_SERVICE_HPP
+
+#include "client_id.hpp"
+#include "id.hpp"
+#include "buffer.hpp"
+
+namespace wsrep
+{
+    // Forward declarations
+    class ws_handle;
+    class ws_meta;
+
+
+    /**
+     * Storage service abstract interface.
+     */
+    class storage_service
+    {
+    public:
+        virtual ~storage_service() { }
+        /**
+         * Start a new transaction for storage access.
+         *
+         * @param ws_hande Write set handle
+         * @param ws_meta Write set meta data
+         *
+         * @return Zero in case of success, non-zero on error.
+         */
+        virtual int start_transaction() = 0;
+
+        /**
+         * Append fragment into stable storage.
+         */
+        virtual int append_fragment(const wsrep::id& server_id,
+                                    wsrep::client_id client_id,
+                                    int flags,
+                                    const wsrep::const_buffer& data) = 0;
+
+        /**
+         * Update fragment meta data after certification process.
+         */
+        virtual int update_fragment_meta(const wsrep::ws_meta&) = 0;
+
+        /**
+         * Commit the transaction.
+         */
+        virtual int commit(const wsrep::ws_handle&, const wsrep::ws_meta&) = 0;
+
+        /**
+         * Roll back the transaction.
+         */
+        virtual int rollback(const wsrep::ws_handle&,
+                             const wsrep::ws_meta&) = 0;
+
+
+        virtual void store_globals() = 0;
+        virtual void reset_globals() = 0;
+    };
+}
+
+#endif // WSREP_STORAGE_SERVICE_HPP