org.apache.flink.runtime.operators.MapPartitionDriver Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
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package org.apache.flink.runtime.operators;
import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.common.functions.MapPartitionFunction;
import org.apache.flink.metrics.Counter;
import org.apache.flink.runtime.operators.util.metrics.CountingCollector;
import org.apache.flink.runtime.operators.util.metrics.CountingMutableObjectIterator;
import org.apache.flink.runtime.util.NonReusingMutableToRegularIteratorWrapper;
import org.apache.flink.runtime.util.ReusingMutableToRegularIteratorWrapper;
import org.apache.flink.util.Collector;
import org.apache.flink.util.MutableObjectIterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* MapPartition task which is executed by a Task Manager. The task has a single
* input and one or multiple outputs. It is provided with a MapFunction
* implementation.
*
* The MapPartitionTask creates an iterator over all key-value pairs of its input and hands that to the map_partition()
method
* of the MapFunction.
*
* @see MapPartitionFunction
*
* @param The mapper's input data type.
* @param The mapper's output data type.
*/
public class MapPartitionDriver implements Driver, OT> {
private static final Logger LOG = LoggerFactory.getLogger(MapPartitionDriver.class);
private TaskContext, OT> taskContext;
private boolean objectReuseEnabled = false;
@Override
public void setup(TaskContext, OT> context) {
this.taskContext = context;
}
@Override
public int getNumberOfInputs() {
return 1;
}
@Override
public Class> getStubType() {
@SuppressWarnings("unchecked")
final Class> clazz = (Class>) (Class) MapPartitionFunction.class;
return clazz;
}
@Override
public int getNumberOfDriverComparators() {
return 0;
}
@Override
public void prepare() {
ExecutionConfig executionConfig = taskContext.getExecutionConfig();
this.objectReuseEnabled = executionConfig.isObjectReuseEnabled();
if (LOG.isDebugEnabled()) {
LOG.debug("MapPartitionDriver object reuse: " + (this.objectReuseEnabled ? "ENABLED" : "DISABLED") + ".");
}
}
@Override
public void run() throws Exception {
final Counter numRecordsIn = this.taskContext.getMetricGroup().getIOMetricGroup().getNumRecordsInCounter();
final Counter numRecordsOut = this.taskContext.getMetricGroup().getIOMetricGroup().getNumRecordsOutCounter();
// cache references on the stack
final MutableObjectIterator input = new CountingMutableObjectIterator<>(this.taskContext.getInput(0), numRecordsIn);
final MapPartitionFunction function = this.taskContext.getStub();
final Collector output = new CountingCollector<>(this.taskContext.getOutputCollector(), numRecordsOut);
if (objectReuseEnabled) {
final ReusingMutableToRegularIteratorWrapper inIter = new ReusingMutableToRegularIteratorWrapper(input, this.taskContext.getInputSerializer(0).getSerializer());
function.mapPartition(inIter, output);
} else {
final NonReusingMutableToRegularIteratorWrapper inIter = new NonReusingMutableToRegularIteratorWrapper(input, this.taskContext.getInputSerializer(0).getSerializer());
function.mapPartition(inIter, output);
}
}
@Override
public void cleanup() {
// mappers need no cleanup, since no strategies are used.
}
@Override
public void cancel() {}
}