/*
* 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.chaining;
import org.apache.flink.api.common.functions.Function;
import org.apache.flink.api.common.functions.GroupReduceFunction;
import org.apache.flink.api.common.functions.util.FunctionUtils;
import org.apache.flink.api.common.typeutils.TypeComparator;
import org.apache.flink.api.common.typeutils.TypeComparatorFactory;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.api.common.typeutils.TypeSerializerFactory;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.core.memory.MemorySegment;
import org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable;
import org.apache.flink.runtime.memory.MemoryManager;
import org.apache.flink.runtime.operators.BatchTask;
import org.apache.flink.runtime.operators.sort.FixedLengthRecordSorter;
import org.apache.flink.runtime.operators.sort.InMemorySorter;
import org.apache.flink.runtime.operators.sort.NormalizedKeySorter;
import org.apache.flink.runtime.operators.sort.QuickSort;
import org.apache.flink.runtime.util.NonReusingKeyGroupedIterator;
import org.apache.flink.runtime.util.ReusingKeyGroupedIterator;
import org.apache.flink.util.Collector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.util.List;
/**
* Chained variant of the GroupReduceCombineDriver
*
* Acts like a combiner with a custom output type OUT.
*
* Sorting and reducing of the elements is performed individually for each partition without data exchange. This may
* lead to a partial group reduce.
*
* @param <IN> The data type consumed
* @param <OUT> The data type produced
*/
public class GroupCombineChainedDriver<IN, OUT> extends ChainedDriver<IN, OUT> {
private static final Logger LOG = LoggerFactory.getLogger(GroupCombineChainedDriver.class);
/** Fix length records with a length below this threshold will be in-place sorted, if possible. */
private static final int THRESHOLD_FOR_IN_PLACE_SORTING = 32;
// --------------------------------------------------------------------------------------------
private InMemorySorter<IN> sorter;
private GroupReduceFunction<IN, OUT> reducer;
private TypeSerializer<IN> serializer;
private TypeComparator<IN> groupingComparator;
private AbstractInvokable parent;
private QuickSort sortAlgo = new QuickSort();
private List<MemorySegment> memory;
private volatile boolean running = true;
// --------------------------------------------------------------------------------------------
@Override
public void setup(AbstractInvokable parent) {
this.parent = parent;
@SuppressWarnings("unchecked")
final GroupReduceFunction<IN, OUT> combiner =
BatchTask.instantiateUserCode(this.config, userCodeClassLoader, GroupReduceFunction.class);
this.reducer = combiner;
FunctionUtils.setFunctionRuntimeContext(combiner, getUdfRuntimeContext());
}
@Override
public void openTask() throws Exception {
// open the stub first
final Configuration stubConfig = this.config.getStubParameters();
BatchTask.openUserCode(this.reducer, stubConfig);
// ----------------- Set up the sorter -------------------------
// instantiate the serializer / comparator
final TypeSerializerFactory<IN> serializerFactory = this.config.getInputSerializer(0, this.userCodeClassLoader);
final TypeComparatorFactory<IN> sortingComparatorFactory = this.config.getDriverComparator(0, this.userCodeClassLoader);
final TypeComparatorFactory<IN> groupingComparatorFactory = this.config.getDriverComparator(1, this.userCodeClassLoader);
this.serializer = serializerFactory.getSerializer();
TypeComparator<IN> sortingComparator = sortingComparatorFactory.createComparator();
this.groupingComparator = groupingComparatorFactory.createComparator();
MemoryManager memManager = this.parent.getEnvironment().getMemoryManager();
final int numMemoryPages = memManager.computeNumberOfPages(this.config.getRelativeMemoryDriver());
this.memory = memManager.allocatePages(this.parent, numMemoryPages);
// instantiate a fix-length in-place sorter, if possible, otherwise the out-of-place sorter
if (sortingComparator.supportsSerializationWithKeyNormalization() &&
this.serializer.getLength() > 0 && this.serializer.getLength() <= THRESHOLD_FOR_IN_PLACE_SORTING)
{
this.sorter = new FixedLengthRecordSorter<IN>(this.serializer, sortingComparator.duplicate(), memory);
} else {
this.sorter = new NormalizedKeySorter<IN>(this.serializer, sortingComparator.duplicate(), memory);
}
if (LOG.isDebugEnabled()) {
LOG.debug("SynchronousChainedCombineDriver object reuse: " + (this.objectReuseEnabled ? "ENABLED" : "DISABLED") + ".");
}
}
@Override
public void closeTask() throws Exception {
if (this.sorter != null) {
this.sorter.dispose();
}
this.parent.getEnvironment().getMemoryManager().release(this.memory);
if (this.running) {
BatchTask.closeUserCode(this.reducer);
}
}
@Override
public void cancelTask() {
this.running = false;
if (this.sorter != null) {
try {
this.sorter.dispose();
}
catch (Exception e) {
// may happen during concurrent modification
}
}
this.parent.getEnvironment().getMemoryManager().release(this.memory);
}
// --------------------------------------------------------------------------------------------
public Function getStub() {
return this.reducer;
}
public String getTaskName() {
return this.taskName;
}
@Override
public void collect(IN record) {
numRecordsIn.inc();
// try writing to the sorter first
try {
if (this.sorter.write(record)) {
return;
}
// do the actual sorting
sortAndReduce();
this.sorter.reset();
if (!this.sorter.write(record)) {
throw new IOException("Cannot write record to fresh sort buffer. Record too large.");
}
}
catch (Exception e) {
throw new ExceptionInChainedStubException(this.taskName, e);
}
}
// --------------------------------------------------------------------------------------------
@Override
public void close() {
try {
sortAndReduce();
} catch (Exception e) {
throw new ExceptionInChainedStubException(this.taskName, e);
}
this.outputCollector.close();
}
private void sortAndReduce() throws Exception {
final InMemorySorter<IN> sorter = this.sorter;
if (objectReuseEnabled) {
if (!sorter.isEmpty()) {
this.sortAlgo.sort(sorter);
// run the reducer
final ReusingKeyGroupedIterator<IN> keyIter = new ReusingKeyGroupedIterator<IN>(
sorter.getIterator(), this.serializer, this.groupingComparator);
// cache references on the stack
final GroupReduceFunction<IN, OUT> stub = this.reducer;
final Collector<OUT> output = this.outputCollector;
// run stub implementation
while (this.running && keyIter.nextKey()) {
stub.reduce(keyIter.getValues(), output);
}
}
} else {
if (!sorter.isEmpty()) {
this.sortAlgo.sort(sorter);
// run the reducer
final NonReusingKeyGroupedIterator<IN> keyIter = new NonReusingKeyGroupedIterator<IN>(
sorter.getIterator(), this.groupingComparator);
// cache references on the stack
final GroupReduceFunction<IN, OUT> stub = this.reducer;
final Collector<OUT> output = this.outputCollector;
// run stub implementation
while (this.running && keyIter.nextKey()) {
stub.reduce(keyIter.getValues(), output);
}
}
}
}
}