/**
* 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.tajo.engine.planner.physical;
import com.google.common.base.Preconditions;
import org.apache.tajo.catalog.Schema;
import org.apache.tajo.catalog.SortSpec;
import org.apache.tajo.datum.Datum;
import org.apache.tajo.datum.NullDatum;
import org.apache.tajo.storage.Tuple;
import java.util.Comparator;
/**
* The Comparator class for Outer and Inner Tuples
*
* @see org.apache.tajo.storage.Tuple
*/
public class JoinTupleComparator implements Comparator<Tuple> {
private int numSortKey;
private final int[] outerSortKeyIds;
private final int[] innerSortKeyIds;
private Datum outer;
private Datum inner;
private int compVal;
public JoinTupleComparator(Schema leftschema, Schema rightschema, SortSpec[][] sortKeys) {
Preconditions.checkArgument(sortKeys.length == 2,
"The two of the sortspecs must be given, but " + sortKeys.length + " sortkeys are given.");
Preconditions.checkArgument(sortKeys[0].length == sortKeys[1].length,
"The number of both side sortkeys must be equals, but they are different: "
+ sortKeys[0].length + " and " + sortKeys[1].length);
this.numSortKey = sortKeys[0].length; // because it is guaranteed that the number of sortspecs are equals
this.outerSortKeyIds = new int[numSortKey];
this.innerSortKeyIds = new int[numSortKey];
for (int i = 0; i < numSortKey; i++) {
this.outerSortKeyIds[i] = leftschema.getColumnId(sortKeys[0][i].getSortKey().getQualifiedName());
this.innerSortKeyIds[i] = rightschema.getColumnId(sortKeys[1][i].getSortKey().getQualifiedName());
}
}
@Override
public int compare(Tuple outerTuple, Tuple innerTuple) {
for (int i = 0; i < numSortKey; i++) {
outer = outerTuple.get(outerSortKeyIds[i]);
inner = innerTuple.get(innerSortKeyIds[i]);
if (outer instanceof NullDatum || inner instanceof NullDatum) {
if (!outer.equals(inner)) {
if (outer instanceof NullDatum) {
compVal = 1;
} else if (inner instanceof NullDatum) {
compVal = -1;
}
} else {
compVal = 0;
}
} else {
compVal = outer.compareTo(inner);
}
if (compVal < 0 || compVal > 0) {
return compVal;
}
}
return 0;
}
}