/*
* 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.FlatJoinFunction;
import org.apache.flink.api.common.typeutils.TypeComparator;
import org.apache.flink.api.common.typeutils.TypePairComparatorFactory;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.metrics.Counter;
import org.apache.flink.runtime.io.disk.iomanager.IOManager;
import org.apache.flink.runtime.memory.MemoryManager;
import org.apache.flink.runtime.operators.util.JoinTaskIterator;
import org.apache.flink.runtime.operators.util.TaskConfig;
import org.apache.flink.runtime.operators.util.metrics.CountingCollector;
import org.apache.flink.runtime.operators.util.metrics.CountingMutableObjectIterator;
import org.apache.flink.util.Collector;
import org.apache.flink.util.MutableObjectIterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The abstract outer join driver implements the logic of an outer join operator at runtime. It instantiates a sort-merge based strategy to find
* joining pairs of records or joining records with null depending on the outer join type.
*
* @see FlatJoinFunction
*/
public abstract class AbstractOuterJoinDriver<IT1, IT2, OT> implements Driver<FlatJoinFunction<IT1, IT2, OT>, OT> {
protected static final Logger LOG = LoggerFactory.getLogger(AbstractOuterJoinDriver.class);
protected TaskContext<FlatJoinFunction<IT1, IT2, OT>, OT> taskContext;
protected volatile JoinTaskIterator<IT1, IT2, OT> outerJoinIterator; // the iterator that does the actual outer join
protected volatile boolean running;
// ------------------------------------------------------------------------
@Override
public void setup(TaskContext<FlatJoinFunction<IT1, IT2, OT>, OT> context) {
this.taskContext = context;
this.running = true;
}
@Override
public int getNumberOfInputs() {
return 2;
}
@Override
public Class<FlatJoinFunction<IT1, IT2, OT>> getStubType() {
@SuppressWarnings("unchecked")
final Class<FlatJoinFunction<IT1, IT2, OT>> clazz = (Class<FlatJoinFunction<IT1, IT2, OT>>) (Class<?>) FlatJoinFunction.class;
return clazz;
}
@Override
public int getNumberOfDriverComparators() {
return 2;
}
@Override
public void prepare() throws Exception {
final TaskConfig config = this.taskContext.getTaskConfig();
// obtain task manager's memory manager and I/O manager
final MemoryManager memoryManager = this.taskContext.getMemoryManager();
final IOManager ioManager = this.taskContext.getIOManager();
// set up memory and I/O parameters
final double driverMemFraction = config.getRelativeMemoryDriver();
final DriverStrategy ls = config.getDriverStrategy();
final Counter numRecordsIn = this.taskContext.getMetricGroup().getIOMetricGroup().getNumRecordsInCounter();
final MutableObjectIterator<IT1> in1 = new CountingMutableObjectIterator<>(this.taskContext.<IT1>getInput(0), numRecordsIn);
final MutableObjectIterator<IT2> in2 = new CountingMutableObjectIterator<>(this.taskContext.<IT2>getInput(1), numRecordsIn);
// get serializers and comparators
final TypeSerializer<IT1> serializer1 = this.taskContext.<IT1>getInputSerializer(0).getSerializer();
final TypeSerializer<IT2> serializer2 = this.taskContext.<IT2>getInputSerializer(1).getSerializer();
final TypeComparator<IT1> comparator1 = this.taskContext.getDriverComparator(0);
final TypeComparator<IT2> comparator2 = this.taskContext.getDriverComparator(1);
final TypePairComparatorFactory<IT1, IT2> pairComparatorFactory = config.getPairComparatorFactory(this.taskContext.getUserCodeClassLoader());
if (pairComparatorFactory == null) {
throw new Exception("Missing pair comparator factory for outer join driver");
}
ExecutionConfig executionConfig = taskContext.getExecutionConfig();
boolean objectReuseEnabled = executionConfig.isObjectReuseEnabled();
if (LOG.isDebugEnabled()) {
LOG.debug("Outer Join Driver object reuse: " + (objectReuseEnabled ? "ENABLED" : "DISABLED") + ".");
}
// create and return outer join iterator according to provided local strategy.
if (objectReuseEnabled) {
this.outerJoinIterator = getReusingOuterJoinIterator(
ls,
in1,
in2,
serializer1,
comparator1,
serializer2,
comparator2,
pairComparatorFactory,
memoryManager,
ioManager,
driverMemFraction
);
} else {
this.outerJoinIterator = getNonReusingOuterJoinIterator(
ls,
in1,
in2,
serializer1,
comparator1,
serializer2,
comparator2,
pairComparatorFactory,
memoryManager,
ioManager,
driverMemFraction
);
}
this.outerJoinIterator.open();
if (LOG.isDebugEnabled()) {
LOG.debug(this.taskContext.formatLogString("outer join task iterator ready."));
}
}
@Override
public void run() throws Exception {
final Counter numRecordsOut = this.taskContext.getMetricGroup().getIOMetricGroup().getNumRecordsOutCounter();
final FlatJoinFunction<IT1, IT2, OT> joinStub = this.taskContext.getStub();
final Collector<OT> collector = new CountingCollector<>(this.taskContext.getOutputCollector(), numRecordsOut);
final JoinTaskIterator<IT1, IT2, OT> outerJoinIterator = this.outerJoinIterator;
while (this.running && outerJoinIterator.callWithNextKey(joinStub, collector)) ;
}
@Override
public void cleanup() throws Exception {
if (this.outerJoinIterator != null) {
this.outerJoinIterator.close();
this.outerJoinIterator = null;
}
}
@Override
public void cancel() {
this.running = false;
if (this.outerJoinIterator != null) {
this.outerJoinIterator.abort();
}
}
protected abstract JoinTaskIterator<IT1, IT2, OT> getReusingOuterJoinIterator(
DriverStrategy driverStrategy,
MutableObjectIterator<IT1> in1,
MutableObjectIterator<IT2> in2,
TypeSerializer<IT1> serializer1,
TypeComparator<IT1> comparator1,
TypeSerializer<IT2> serializer2,
TypeComparator<IT2> comparator2,
TypePairComparatorFactory<IT1, IT2> pairComparatorFactory,
MemoryManager memoryManager,
IOManager ioManager,
double driverMemFraction
) throws Exception;
protected abstract JoinTaskIterator<IT1, IT2, OT> getNonReusingOuterJoinIterator(
DriverStrategy driverStrategy,
MutableObjectIterator<IT1> in1,
MutableObjectIterator<IT2> in2,
TypeSerializer<IT1> serializer1,
TypeComparator<IT1> comparator1,
TypeSerializer<IT2> serializer2,
TypeComparator<IT2> comparator2,
TypePairComparatorFactory<IT1, IT2> pairComparatorFactory,
MemoryManager memoryManager,
IOManager ioManager,
double driverMemFraction
) throws Exception;
}