| /** |
| * 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. |
| */ |
| |
| package org.apache.hadoop.hbase.procedure2; |
| |
| import java.io.IOException; |
| |
| import org.apache.yetus.audience.InterfaceAudience; |
| import org.apache.yetus.audience.InterfaceStability; |
| import org.apache.hadoop.hbase.shaded.protobuf.generated.ProcedureProtos.SequentialProcedureData; |
| |
| /** |
| * A SequentialProcedure describes one step in a procedure chain: |
| * <pre> |
| * -> Step 1 -> Step 2 -> Step 3 |
| * </pre> |
| * The main difference from a base Procedure is that the execute() of a |
| * SequentialProcedure will be called only once; there will be no second |
| * execute() call once the children are finished. which means once the child |
| * of a SequentialProcedure are completed the SequentialProcedure is completed too. |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| public abstract class SequentialProcedure<TEnvironment> extends Procedure<TEnvironment> { |
| private boolean executed = false; |
| |
| @Override |
| protected Procedure[] doExecute(final TEnvironment env) |
| throws ProcedureYieldException, ProcedureSuspendedException, InterruptedException { |
| updateTimestamp(); |
| try { |
| Procedure[] children = !executed ? execute(env) : null; |
| executed = !executed; |
| return children; |
| } finally { |
| updateTimestamp(); |
| } |
| } |
| |
| @Override |
| protected void doRollback(final TEnvironment env) |
| throws IOException, InterruptedException { |
| updateTimestamp(); |
| if (executed) { |
| try { |
| rollback(env); |
| executed = !executed; |
| } finally { |
| updateTimestamp(); |
| } |
| } |
| } |
| |
| @Override |
| protected void serializeStateData(ProcedureStateSerializer serializer) |
| throws IOException { |
| SequentialProcedureData.Builder data = SequentialProcedureData.newBuilder(); |
| data.setExecuted(executed); |
| serializer.serialize(data.build()); |
| } |
| |
| @Override |
| protected void deserializeStateData(ProcedureStateSerializer serializer) |
| throws IOException { |
| SequentialProcedureData data = serializer.deserialize(SequentialProcedureData.class); |
| executed = data.getExecuted(); |
| } |
| } |