org.apache.flink.runtime.operators.NoOpDriver 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;
import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.common.functions.AbstractRichFunction;
import org.apache.flink.metrics.Counter;
import org.apache.flink.runtime.operators.util.metrics.CountingCollector;
import org.apache.flink.util.Collector;
import org.apache.flink.util.MutableObjectIterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A driver that does nothing but forward data from its input to its output.
*
* @param The data type.
*/
public class NoOpDriver implements Driver {
private static final Logger LOG = LoggerFactory.getLogger(NoOpDriver.class);
private TaskContext taskContext;
private volatile boolean running;
private boolean objectReuseEnabled = false;
@Override
public void setup(TaskContext context) {
this.taskContext = context;
this.running = true;
}
@Override
public int getNumberOfInputs() {
return 1;
}
@Override
public Class getStubType() {
return null;
}
@Override
public int getNumberOfDriverComparators() {
return 0;
}
@Override
public void prepare() {
ExecutionConfig executionConfig = taskContext.getExecutionConfig();
this.objectReuseEnabled = executionConfig.isObjectReuseEnabled();
if (LOG.isDebugEnabled()) {
LOG.debug("NoOpDriver object reuse: " + (this.objectReuseEnabled ? "ENABLED" : "DISABLED") + ".");
}
}
@Override
public void run() throws Exception {
// cache references on the stack
final Counter numRecordsIn = this.taskContext.getMetricGroup().counter("numRecordsIn");
final Counter numRecordsOut = this.taskContext.getMetricGroup().counter("numRecordsOut");
final MutableObjectIterator input = this.taskContext.getInput(0);
final Collector output = new CountingCollector<>(this.taskContext.getOutputCollector(), numRecordsOut);
if (objectReuseEnabled) {
T record = this.taskContext.getInputSerializer(0).getSerializer().createInstance();
while (this.running && ((record = input.next(record)) != null)) {
numRecordsIn.inc();
output.collect(record);
}
} else {
T record;
while (this.running && ((record = input.next()) != null)) {
numRecordsIn.inc();
output.collect(record);
}
}
}
@Override
public void cleanup() {}
@Override
public void cancel() {
this.running = false;
}
}