org.apache.flink.streaming.api.operators.StreamProject 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.flink.streaming.api.operators;
import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.api.java.tuple.Tuple;
import org.apache.flink.streaming.runtime.streamrecord.StreamRecord;
/**
* A {@link StreamOperator} for executing projections on streams.
*/
@Internal
public class StreamProject
extends AbstractStreamOperator
implements OneInputStreamOperator {
private static final long serialVersionUID = 1L;
private TypeSerializer outSerializer;
private int[] fields;
private int numFields;
private transient OUT outTuple;
public StreamProject(int[] fields, TypeSerializer outSerializer) {
this.fields = fields;
this.numFields = this.fields.length;
this.outSerializer = outSerializer;
chainingStrategy = ChainingStrategy.ALWAYS;
}
@Override
public void processElement(StreamRecord element) throws Exception {
for (int i = 0; i < this.numFields; i++) {
outTuple.setField(((Tuple) element.getValue()).getField(fields[i]), i);
}
output.collect(element.replace(outTuple));
}
@Override
public void open() throws Exception {
super.open();
outTuple = outSerializer.createInstance();
}
}