/**
* 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.storage.Tuple;
public abstract class Partitioner {
protected final int [] partitionKeyIds;
protected final int numPartitions;
public Partitioner(final int [] keyList, final int numPartitions) {
Preconditions.checkArgument(keyList != null,
"Partition keys must be given");
Preconditions.checkArgument(keyList.length >= 0,
"At least one partition key must be specified.");
// In outer join, zero can be passed into this value because of empty tables.
// So, we should allow zero.
Preconditions.checkArgument(numPartitions >= 0,
"The number of partitions must be positive: %s", numPartitions);
this.partitionKeyIds = keyList;
this.numPartitions = numPartitions;
}
public abstract int getPartition(Tuple tuple);
}