io.cdap.wrangler.statistics.Statistics Maven / Gradle / Ivy
/*
* Copyright © 2017-2019 Cask Data, Inc.
*
* 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 io.cdap.wrangler.statistics;
import io.cdap.wrangler.api.Row;
import io.cdap.wrangler.api.annotations.PublicEvolving;
import java.util.List;
/**
* Interface for calculating metrics over the records being processed.
*/
@PublicEvolving
public interface Statistics {
/**
* Aggregates statistics for all the rows.
*
* @param rows to be aggregated.
* @return Summary in the form of {@link Row}
*/
Row aggregate(List rows);
}