external/storm-cassandra/src/main/java/org/apache/storm/cassandra/bolt/CassandraWriterBolt.java

/**
 * 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.storm.cassandra.bolt;

import com.datastax.driver.core.Statement;
import java.util.List;
import org.apache.storm.cassandra.executor.AsyncResultHandler;
import org.apache.storm.cassandra.executor.impl.SingleAsyncResultHandler;
import org.apache.storm.cassandra.query.CQLStatementTupleMapper;
import org.apache.storm.tuple.Tuple;

public class CassandraWriterBolt extends BaseCassandraBolt<Tuple> {

    private AsyncResultHandler<Tuple> asyncResultHandler;

    /**
     * Creates a new {@link CassandraWriterBolt} instance.
     */
    public CassandraWriterBolt(CQLStatementTupleMapper tupleMapper) {
        super(tupleMapper);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected AsyncResultHandler<Tuple> getAsyncHandler() {
        if (asyncResultHandler == null) {
            asyncResultHandler = new SingleAsyncResultHandler(getResultHandler());
        }
        return asyncResultHandler;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void process(Tuple input) {
        List<Statement> statements = getMapper().map(topoConfig, session, input);
        if (statements.size() == 1) {
            getAsyncExecutor().execAsync(statements.get(0), input);
        } else {
            getAsyncExecutor().execAsync(statements, input);
        }
    }
}