/**
* Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
*
* 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 com.linkedin.pinot.core.query.aggregation;
import com.linkedin.pinot.common.request.AggregationInfo;
import com.linkedin.pinot.core.query.aggregation.function.AggregationFunction;
import com.linkedin.pinot.core.query.aggregation.function.AggregationFunctionFactory;
/**
* This class caches miscellaneous data to perform efficient aggregation.
*/
public class AggregationFunctionContext {
private final AggregationFunction _aggregationFunction;
private final String[] _aggrColumns;
public static AggregationFunctionContext instantiate(AggregationInfo aggregationInfo) {
String[] aggrColumns = aggregationInfo.getAggregationParams().get("column").trim().split(",");
String functionName = aggregationInfo.getAggregationType();
AggregationFunction aggregationFunction = AggregationFunctionFactory.getAggregationFunction(functionName);
return new AggregationFunctionContext(aggrColumns, aggregationFunction);
}
public AggregationFunctionContext(String[] aggrColumns, AggregationFunction aggregationFunction) {
_aggrColumns = aggrColumns;
_aggregationFunction = aggregationFunction;
}
/**
* Returns the aggregation function object.
* @return
*/
public AggregationFunction getAggregationFunction() {
return _aggregationFunction;
}
/**
* Returns an array of aggregation column names.
* @return
*/
public String[] getAggregationColumns() {
return _aggrColumns;
}
/**
* Returns the aggregation column name for the results.
*/
public String getAggregationColumnName() {
return _aggregationFunction.getColumnName(_aggrColumns);
}
}