org.apache.hadoop.hbase.procedure2.SequentialProcedure Maven / Gradle / Ivy
/*
* 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:
*
*
* -> Step 1 -> Step 2 -> Step 3
*
*
* 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 extends Procedure {
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();
}
}