org.apache.flink.runtime.operators.shipping.OutputCollector 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.runtime.operators.shipping;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.runtime.io.network.api.writer.RecordWriter;
import org.apache.flink.runtime.plugable.SerializationDelegate;
import org.apache.flink.util.Collector;
import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
/**
* The OutputCollector collects records, and emits them to the {@link RecordWriter}s.
* The OutputCollector tracks to which writers a deep-copy must be given and which not.
*/
public class OutputCollector implements Collector {
// list of writers
private final RecordWriter>[] writers;
private final SerializationDelegate delegate;
/**
* Initializes the output collector with a set of writers.
* To specify for a writer that it must be fed with a deep-copy, set the bit in the copy flag bit mask to 1 that
* corresponds to the position of the writer within the {@link List}.
*
* @param writers List of all writers.
*/
@SuppressWarnings("unchecked")
public OutputCollector(List>> writers, TypeSerializer serializer) {
this.delegate = new SerializationDelegate(serializer);
this.writers = (RecordWriter>[]) writers.toArray(new RecordWriter[writers.size()]);
}
/**
* Collects a record and emits it to all writers.
*/
@Override
public void collect(T record) {
if (record != null) {
this.delegate.setInstance(record);
try {
for (RecordWriter> writer : writers) {
writer.emit(this.delegate);
}
}
catch (IOException e) {
throw new RuntimeException("Emitting the record caused an I/O exception: " + e.getMessage(), e);
}
catch (InterruptedException e) {
throw new RuntimeException("Emitting the record was interrupted: " + e.getMessage(), e);
}
}
else {
throw new NullPointerException("The system does not support records that are null."
+ "Null values are only supported as fields inside other objects.");
}
}
@Override
public void close() {
for (RecordWriter writer : writers) {
writer.clearBuffers();
writer.flushAll();
}
}
/**
* List of writers that are associated with this output collector
* @return list of writers
*/
@SuppressWarnings("unchecked")
public List>> getWriters() {
return Collections.unmodifiableList(Arrays.asList(this.writers));
}
}