/***********************************************************************************************************************
* 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.Ordering;
import eu.stratosphere.api.common.operators.util.FieldList;
import eu.stratosphere.compiler.CompilerException;
import eu.stratosphere.compiler.dag.TwoInputNode;
import eu.stratosphere.compiler.dataproperties.LocalProperties;
import eu.stratosphere.compiler.dataproperties.RequestedLocalProperties;
import eu.stratosphere.compiler.plan.Channel;
import eu.stratosphere.compiler.plan.DualInputPlanNode;
import eu.stratosphere.compiler.util.Utils;
import eu.stratosphere.pact.runtime.task.DriverStrategy;
/**
*
*/
public class SortMergeJoinDescriptor extends AbstractJoinDescriptor
{
public SortMergeJoinDescriptor(FieldList keys1, FieldList keys2) {
super(keys1, keys2);
}
@Override
public DriverStrategy getStrategy() {
return DriverStrategy.MERGE;
}
@Override
protected List<LocalPropertiesPair> createPossibleLocalProperties() {
RequestedLocalProperties sort1 = new RequestedLocalProperties(Utils.createOrdering(this.keys1));
RequestedLocalProperties sort2 = new RequestedLocalProperties(Utils.createOrdering(this.keys2));
return Collections.singletonList(new LocalPropertiesPair(sort1, sort2));
}
@Override
public boolean areCoFulfilled(RequestedLocalProperties requested1, RequestedLocalProperties requested2,
LocalProperties produced1, LocalProperties produced2)
{
int numRelevantFields = this.keys1.size();
Ordering prod1 = produced1.getOrdering();
Ordering prod2 = produced2.getOrdering();
if (prod1 == null || prod2 == null || prod1.getNumberOfFields() < numRelevantFields ||
prod2.getNumberOfFields() < prod2.getNumberOfFields())
{
throw new CompilerException("The given properties do not meet this operators requirements.");
}
for (int i = 0; i < numRelevantFields; i++) {
if (prod1.getOrder(i) != prod2.getOrder(i)) {
return false;
}
}
return true;
}
@Override
public DualInputPlanNode instantiate(Channel in1, Channel in2, TwoInputNode node) {
boolean[] inputOrders = in1.getLocalProperties().getOrdering().getFieldSortDirections();
if (inputOrders == null || inputOrders.length < this.keys1.size()) {
throw new CompilerException("BUG: The input strategy does not sufficiently describe the sort orders for a merge operator.");
} else if (inputOrders.length > this.keys1.size()) {
boolean[] tmp = new boolean[this.keys1.size()];
System.arraycopy(inputOrders, 0, tmp, 0, tmp.length);
inputOrders = tmp;
}
return new DualInputPlanNode(node, "Join("+node.getPactContract().getName()+")", in1, in2, DriverStrategy.MERGE, this.keys1, this.keys2, inputOrders);
}
@Override
public LocalProperties computeLocalProperties(LocalProperties in1, LocalProperties in2) {
LocalProperties comb = LocalProperties.combine(in1, in2);
comb.clearUniqueFieldSets();
return comb;
}
}