/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed 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 eu.stratosphere.pact.runtime.task.chaining;
import java.io.IOException;
import java.util.List;
import eu.stratosphere.api.common.functions.Function;
import eu.stratosphere.api.common.functions.GenericCombine;
import eu.stratosphere.api.common.typeutils.TypeComparator;
import eu.stratosphere.api.common.typeutils.TypeComparatorFactory;
import eu.stratosphere.api.common.typeutils.TypeSerializer;
import eu.stratosphere.api.common.typeutils.TypeSerializerFactory;
import eu.stratosphere.configuration.Configuration;
import eu.stratosphere.core.memory.MemorySegment;
import eu.stratosphere.nephele.services.memorymanager.MemoryManager;
import eu.stratosphere.nephele.template.AbstractInvokable;
import eu.stratosphere.pact.runtime.sort.FixedLengthRecordSorter;
import eu.stratosphere.pact.runtime.sort.InMemorySorter;
import eu.stratosphere.pact.runtime.sort.NormalizedKeySorter;
import eu.stratosphere.pact.runtime.sort.QuickSort;
import eu.stratosphere.pact.runtime.task.RegularPactTask;
import eu.stratosphere.pact.runtime.util.KeyGroupedIterator;
import eu.stratosphere.util.Collector;
public class SynchronousChainedCombineDriver<T> extends ChainedDriver<T, T> {
/**
* 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<T> sorter;
private GenericCombine<T> combiner;
private TypeSerializer<T> serializer;
private TypeComparator<T> comparator;
private AbstractInvokable parent;
private QuickSort sortAlgo = new QuickSort();
private MemoryManager memManager;
private volatile boolean running = true;
// --------------------------------------------------------------------------------------------
@Override
public void setup(AbstractInvokable parent) {
this.parent = parent;
@SuppressWarnings("unchecked")
final GenericCombine<T> combiner =
RegularPactTask.instantiateUserCode(this.config, userCodeClassLoader, GenericCombine.class);
this.combiner = combiner;
combiner.setRuntimeContext(getUdfRuntimeContext());
}
@Override
public void openTask() throws Exception {
// open the stub first
final Configuration stubConfig = this.config.getStubParameters();
RegularPactTask.openUserCode(this.combiner, stubConfig);
// ----------------- Set up the asynchronous sorter -------------------------
this.memManager = this.parent.getEnvironment().getMemoryManager();
final int numMemoryPages = memManager.computeNumberOfPages(this.config.getMemoryDriver());
// instantiate the serializer / comparator
final TypeSerializerFactory<T> serializerFactory = this.config.getInputSerializer(0, this.userCodeClassLoader);
final TypeComparatorFactory<T> comparatorFactory = this.config.getDriverComparator(0, this.userCodeClassLoader);
this.serializer = serializerFactory.getSerializer();
this.comparator = comparatorFactory.createComparator();
final List<MemorySegment> memory = this.memManager.allocatePages(this.parent, numMemoryPages);
// instantiate a fix-length in-place sorter, if possible, otherwise the out-of-place sorter
if (this.comparator.supportsSerializationWithKeyNormalization() &&
this.serializer.getLength() > 0 && this.serializer.getLength() <= THRESHOLD_FOR_IN_PLACE_SORTING)
{
this.sorter = new FixedLengthRecordSorter<T>(this.serializer, this.comparator, memory);
} else {
this.sorter = new NormalizedKeySorter<T>(this.serializer, this.comparator.duplicate(), memory);
}
}
@Override
public void closeTask() throws Exception {
this.memManager.release(this.sorter.dispose());
if (!this.running) {
return;
}
RegularPactTask.closeUserCode(this.combiner);
}
@Override
public void cancelTask() {
this.running = false;
this.memManager.release(this.sorter.dispose());
}
// --------------------------------------------------------------------------------------------
public Function getStub() {
return this.combiner;
}
public String getTaskName() {
return this.taskName;
}
@Override
public void collect(T record) {
// try writing to the sorter first
try {
if (this.sorter.write(record)) {
return;
}
} catch (IOException e) {
throw new ExceptionInChainedStubException(this.taskName, e);
}
// do the actual sorting
try {
sortAndCombine();
} catch (Exception e) {
throw new ExceptionInChainedStubException(this.taskName, e);
}
this.sorter.reset();
try {
if (!this.sorter.write(record)) {
throw new IOException("Cannot write record to fresh sort buffer. Record too large.");
}
} catch (IOException e) {
throw new ExceptionInChainedStubException(this.taskName, e);
}
}
// --------------------------------------------------------------------------------------------
@Override
public void close() {
try {
sortAndCombine();
} catch (Exception e) {
throw new ExceptionInChainedStubException(this.taskName, e);
}
this.outputCollector.close();
}
private void sortAndCombine() throws Exception {
final InMemorySorter<T> sorter = this.sorter;
if (!sorter.isEmpty()) {
this.sortAlgo.sort(sorter);
// run the combiner
final KeyGroupedIterator<T> keyIter = new KeyGroupedIterator<T>(sorter.getIterator(), this.serializer,
this.comparator);
// cache references on the stack
final GenericCombine<T> stub = this.combiner;
final Collector<T> output = this.outputCollector;
// run stub implementation
while (this.running && keyIter.nextKey()) {
stub.combine(keyIter.getValues(), output);
}
}
}
}