/***********************************************************************************************************************
* 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.compiler.operators;
import java.util.Collections;
import java.util.List;
import eu.stratosphere.api.common.operators.Order;
import eu.stratosphere.api.common.operators.Ordering;
import eu.stratosphere.api.common.operators.util.FieldSet;
import eu.stratosphere.compiler.dag.SingleInputNode;
import eu.stratosphere.compiler.dataproperties.GlobalProperties;
import eu.stratosphere.compiler.dataproperties.LocalProperties;
import eu.stratosphere.compiler.dataproperties.PartitioningProperty;
import eu.stratosphere.compiler.dataproperties.RequestedGlobalProperties;
import eu.stratosphere.compiler.dataproperties.RequestedLocalProperties;
import eu.stratosphere.compiler.plan.Channel;
import eu.stratosphere.compiler.plan.SingleInputPlanNode;
import eu.stratosphere.pact.runtime.task.DriverStrategy;
public final class GroupReduceProperties extends OperatorDescriptorSingle {
private final Ordering ordering; // ordering that we need to use if an additional ordering is requested
public GroupReduceProperties(FieldSet keys) {
this(keys, null);
}
public GroupReduceProperties(FieldSet groupKeys, Ordering additionalOrderKeys) {
super(groupKeys);
// if we have an additional ordering, construct the ordering to have primarily the grouping fields
if (additionalOrderKeys != null) {
this.ordering = new Ordering();
for (Integer key : this.keyList) {
this.ordering.appendOrdering(key, null, Order.ANY);
}
// and next the additional order fields
for (int i = 0; i < additionalOrderKeys.getNumberOfFields(); i++) {
Integer field = additionalOrderKeys.getFieldNumber(i);
Order order = additionalOrderKeys.getOrder(i);
this.ordering.appendOrdering(field, additionalOrderKeys.getType(i), order);
}
} else {
this.ordering = null;
}
}
@Override
public DriverStrategy getStrategy() {
return DriverStrategy.SORTED_GROUP_REDUCE;
}
@Override
public SingleInputPlanNode instantiate(Channel in, SingleInputNode node) {
return new SingleInputPlanNode(node, "Reduce("+node.getPactContract().getName()+")", in, DriverStrategy.SORTED_GROUP_REDUCE, this.keyList);
}
@Override
protected List<RequestedGlobalProperties> createPossibleGlobalProperties() {
RequestedGlobalProperties props = new RequestedGlobalProperties();
props.setAnyPartitioning(this.keys);
return Collections.singletonList(props);
}
@Override
protected List<RequestedLocalProperties> createPossibleLocalProperties() {
RequestedLocalProperties props = new RequestedLocalProperties();
if (this.ordering == null) {
props.setGroupedFields(this.keys);
} else {
props.setOrdering(this.ordering);
}
return Collections.singletonList(props);
}
@Override
public GlobalProperties computeGlobalProperties(GlobalProperties gProps) {
if (gProps.getUniqueFieldCombination() != null && gProps.getUniqueFieldCombination().size() > 0 &&
gProps.getPartitioning() == PartitioningProperty.RANDOM)
{
gProps.setAnyPartitioning(gProps.getUniqueFieldCombination().iterator().next().toFieldList());
}
gProps.clearUniqueFieldCombinations();
return gProps;
}
@Override
public LocalProperties computeLocalProperties(LocalProperties lProps) {
lProps.clearUniqueFieldSets();
return lProps;
}
}