eu.stratosphere.pact.runtime.task.CrossDriver Maven / Gradle / Ivy
/***********************************************************************************************************************
* 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;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import eu.stratosphere.api.common.functions.GenericCrosser;
import eu.stratosphere.api.common.typeutils.TypeSerializer;
import eu.stratosphere.nephele.services.memorymanager.MemoryManager;
import eu.stratosphere.pact.runtime.resettable.BlockResettableMutableObjectIterator;
import eu.stratosphere.pact.runtime.resettable.SpillingResettableMutableObjectIterator;
import eu.stratosphere.pact.runtime.task.util.TaskConfig;
import eu.stratosphere.util.Collector;
import eu.stratosphere.util.MutableObjectIterator;
/**
* Cross task which is executed by a Nephele task manager. The task has two
* inputs and one or multiple outputs. It is provided with a CrossFunction
* implementation.
*
* The CrossTask builds the Cartesian product of the pairs of its two inputs. Each element (pair of pairs) is handed to
* the cross() method of the CrossFunction.
*
* @see eu.stratosphere.api.java.functions.CrossFunction
*/
public class CrossDriver implements PactDriver, OT> {
private static final Log LOG = LogFactory.getLog(CrossDriver.class);
private PactTaskContext, OT> taskContext;
private MemoryManager memManager;
private SpillingResettableMutableObjectIterator spillIter;
private BlockResettableMutableObjectIterator blockIter;
private int memPagesForBlockSide;
private int memPagesForSpillingSide;
private boolean blocked;
private boolean firstIsOuter;
private volatile boolean running;
// ------------------------------------------------------------------------
@Override
public void setup(PactTaskContext, OT> context) {
this.taskContext = context;
this.running = true;
}
@Override
public int getNumberOfInputs() {
return 2;
}
@Override
public Class> getStubType() {
@SuppressWarnings("unchecked")
final Class> clazz = (Class>) (Class) GenericCrosser.class;
return clazz;
}
@Override
public boolean requiresComparatorOnInput() {
return false;
}
@Override
public void prepare() throws Exception {
final TaskConfig config = this.taskContext.getTaskConfig();
final DriverStrategy ls = config.getDriverStrategy();
switch (ls)
{
case NESTEDLOOP_BLOCKED_OUTER_FIRST:
this.blocked = true;
this.firstIsOuter = true;
break;
case NESTEDLOOP_BLOCKED_OUTER_SECOND:
this.blocked = true;
this.firstIsOuter = false;
break;
case NESTEDLOOP_STREAMED_OUTER_FIRST:
this.blocked = false;
this.firstIsOuter = true;
break;
case NESTEDLOOP_STREAMED_OUTER_SECOND:
this.blocked = false;
this.firstIsOuter = false;
break;
default:
throw new RuntimeException("Invalid local strategy for CROSS: " + ls);
}
this.memManager = this.taskContext.getMemoryManager();
final long totalAvailableMemory = config.getMemoryDriver();
final int numPages = this.memManager.computeNumberOfPages(totalAvailableMemory);
if (numPages < 2) {
throw new RuntimeException( "The Cross task was initialized with too little memory. " +
"Cross requires at least 2 memory pages.");
}
// divide memory between spilling and blocking side
if (ls == DriverStrategy.NESTEDLOOP_STREAMED_OUTER_FIRST || ls == DriverStrategy.NESTEDLOOP_STREAMED_OUTER_SECOND) {
this.memPagesForSpillingSide = numPages;
this.memPagesForBlockSide = 0;
} else {
if (numPages > 32) {
this.memPagesForSpillingSide = 2;
} else {
this.memPagesForSpillingSide = 1;
}
this.memPagesForBlockSide = numPages - this.memPagesForSpillingSide;
}
}
@Override
public void run() throws Exception {
if (this.blocked) {
if (this.firstIsOuter) {
runBlockedOuterFirst();
} else {
runBlockedOuterSecond();
}
} else {
if (this.firstIsOuter) {
runStreamedOuterFirst();
} else {
runStreamedOuterSecond();
}
}
}
@Override
public void cleanup() throws Exception {
if (this.spillIter != null) {
this.spillIter.close();
this.spillIter = null;
}
if (this.blockIter != null) {
this.blockIter.close();
this.blockIter = null;
}
}
@Override
public void cancel() {
this.running = false;
}
private void runBlockedOuterFirst() throws Exception {
if (LOG.isDebugEnabled()) {
LOG.debug(this.taskContext.formatLogString("Running Cross with Block-Nested-Loops: " +
"First input is outer (blocking) side, second input is inner (spilling) side."));
}
final MutableObjectIterator in1 = this.taskContext.getInput(0);
final MutableObjectIterator in2 = this.taskContext.getInput(1);
final TypeSerializer serializer1 = this.taskContext.getInputSerializer(0).getSerializer();
final TypeSerializer serializer2 = this.taskContext.getInputSerializer(1).getSerializer();
final BlockResettableMutableObjectIterator blockVals =
new BlockResettableMutableObjectIterator(this.memManager, in1, serializer1, this.memPagesForBlockSide,
this.taskContext.getOwningNepheleTask());
this.blockIter = blockVals;
final SpillingResettableMutableObjectIterator spillVals = new SpillingResettableMutableObjectIterator(
in2, serializer2, this.memManager, this.taskContext.getIOManager(), this.memPagesForSpillingSide,
this.taskContext.getOwningNepheleTask());
this.spillIter = spillVals;
T1 val1;
final T1 val1Reuse = serializer1.createInstance();
T2 val2;
final T2 val2Reuse = serializer2.createInstance();
T2 val2Copy = serializer2.createInstance();
final GenericCrosser crosser = this.taskContext.getStub();
final Collector collector = this.taskContext.getOutputCollector();
// for all blocks
do {
// for all values from the spilling side
while (this.running && ((val2 = spillVals.next(val2Reuse)) != null)) {
// for all values in the block
while ((val1 = blockVals.next(val1Reuse)) != null) {
val2Copy = serializer2.copy(val2, val2Copy);
crosser.cross(val1, val2Copy, collector);
}
blockVals.reset();
}
spillVals.reset();
}
while (this.running && blockVals.nextBlock());
}
private void runBlockedOuterSecond() throws Exception {
if (LOG.isDebugEnabled()) {
LOG.debug(this.taskContext.formatLogString("Running Cross with Block-Nested-Loops: " +
"First input is inner (spilling) side, second input is outer (blocking) side."));
}
final MutableObjectIterator in1 = this.taskContext.getInput(0);
final MutableObjectIterator in2 = this.taskContext.getInput(1);
final TypeSerializer serializer1 = this.taskContext.getInputSerializer(0).getSerializer();
final TypeSerializer serializer2 = this.taskContext.getInputSerializer(1).getSerializer();
final SpillingResettableMutableObjectIterator spillVals = new SpillingResettableMutableObjectIterator(
in1, serializer1, this.memManager, this.taskContext.getIOManager(), this.memPagesForSpillingSide,
this.taskContext.getOwningNepheleTask());
this.spillIter = spillVals;
final BlockResettableMutableObjectIterator blockVals =
new BlockResettableMutableObjectIterator(this.memManager, in2, serializer2, this.memPagesForBlockSide,
this.taskContext.getOwningNepheleTask());
this.blockIter = blockVals;
T1 val1;
final T1 val1Reuse = serializer1.createInstance();
T1 val1Copy = serializer1.createInstance();
T2 val2;
final T2 val2Reuse = serializer2.createInstance();
final GenericCrosser crosser = this.taskContext.getStub();
final Collector collector = this.taskContext.getOutputCollector();
// for all blocks
do {
// for all values from the spilling side
while (this.running && ((val1 = spillVals.next(val1Reuse)) != null)) {
// for all values in the block
while (this.running && ((val2 = blockVals.next(val2Reuse)) != null)) {
val1Copy = serializer1.copy(val1, val1Copy);
crosser.cross(val1Copy, val2, collector);
}
blockVals.reset();
}
spillVals.reset();
}
while (this.running && blockVals.nextBlock());
}
private void runStreamedOuterFirst() throws Exception {
if (LOG.isDebugEnabled()) {
LOG.debug(this.taskContext.formatLogString("Running Cross with Nested-Loops: " +
"First input is outer side, second input is inner (spilling) side."));
}
final MutableObjectIterator in1 = this.taskContext.getInput(0);
final MutableObjectIterator in2 = this.taskContext.getInput(1);
final TypeSerializer serializer1 = this.taskContext.getInputSerializer(0).getSerializer();
final TypeSerializer serializer2 = this.taskContext.getInputSerializer(1).getSerializer();
final SpillingResettableMutableObjectIterator spillVals = new SpillingResettableMutableObjectIterator(
in2, serializer2, this.memManager, this.taskContext.getIOManager(), this.memPagesForSpillingSide,
this.taskContext.getOwningNepheleTask());
this.spillIter = spillVals;
T1 val1;
final T1 val1Reuse = serializer1.createInstance();
T1 val1Copy = serializer1.createInstance();
T2 val2;
final T2 val2Reuse = serializer2.createInstance();
final GenericCrosser crosser = this.taskContext.getStub();
final Collector collector = this.taskContext.getOutputCollector();
// for all blocks
while (this.running && ((val1 = in1.next(val1Reuse)) != null)) {
// for all values from the spilling side
while (this.running && ((val2 = spillVals.next(val2Reuse)) != null)) {
val1Copy = serializer1.copy(val1, val1Copy);
crosser.cross(val1Copy, val2, collector);
}
spillVals.reset();
}
}
private void runStreamedOuterSecond() throws Exception {
if (LOG.isDebugEnabled()) {
LOG.debug(this.taskContext.formatLogString("Running Cross with Nested-Loops: " +
"First input is inner (spilling) side, second input is outer side."));
}
final MutableObjectIterator in1 = this.taskContext.getInput(0);
final MutableObjectIterator in2 = this.taskContext.getInput(1);
final TypeSerializer serializer1 = this.taskContext.getInputSerializer(0).getSerializer();
final TypeSerializer serializer2 = this.taskContext.getInputSerializer(1).getSerializer();
final SpillingResettableMutableObjectIterator spillVals = new SpillingResettableMutableObjectIterator(
in1, serializer1, this.memManager, this.taskContext.getIOManager(), this.memPagesForSpillingSide,
this.taskContext.getOwningNepheleTask());
this.spillIter = spillVals;
T1 val1;
final T1 val1Reuse = serializer1.createInstance();
T2 val2;
final T2 val2Reuse = serializer2.createInstance();
T2 val2Copy = serializer2.createInstance();
final GenericCrosser crosser = this.taskContext.getStub();
final Collector collector = this.taskContext.getOutputCollector();
// for all blocks
while (this.running && (val2 = in2.next(val2Reuse)) != null) {
// for all values from the spilling side
while (this.running && (val1 = spillVals.next(val1Reuse)) != null) {
val2Copy = serializer2.copy(val2, val2Copy);
crosser.cross(val1, val2Copy, collector);
}
spillVals.reset();
}
}
}