1 files changed, 59 insertions, 0 deletions
diff --git a/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/statemachine/commandhandler/CommandHandler.java b/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/statemachine/commandhandler/CommandHandler.java
new file mode 100644
index 0000000000..13d9f7295d
--- /dev/null
+++ b/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/statemachine/commandhandler/CommandHandler.java
@@ -0,0 +1,59 @@
+/**
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.
+ */
+
+package org.apache.hadoop.ozone.container.common.statemachine.commandhandler;
+
+import org.apache.hadoop.hdds.protocol.proto.StorageContainerDatanodeProtocolProtos.SCMCmdType;
+import org.apache.hadoop.ozone.container.common.statemachine.SCMConnectionManager;
+import org.apache.hadoop.ozone.container.common.statemachine.StateContext;
+import org.apache.hadoop.ozone.container.ozoneimpl.OzoneContainer;
+import org.apache.hadoop.ozone.protocol.commands.SCMCommand;
+
+/**
+ * Generic interface for handlers.
+ */
+public interface CommandHandler {
+
+  /**
+   * Handles a given SCM command.
+   * @param command - SCM Command
+   * @param container - Ozone Container.
+   * @param context - Current Context.
+   * @param connectionManager - The SCMs that we are talking to.
+   */
+  void handle(SCMCommand command, OzoneContainer container,
+      StateContext context, SCMConnectionManager connectionManager);
+
+  /**
+   * Returns the command type that this command handler handles.
+   * @return Type
+   */
+  SCMCmdType getCommandType();
+
+  /**
+   * Returns number of times this handler has been invoked.
+   * @return int
+   */
+  int getInvocationCount();
+
+  /**
+   * Returns the average time this function takes to run.
+   * @return  long
+   */
+  long getAverageRunTime();
+
+}