/*
* Copyright 2015 LinkedIn Corp.
*
* 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 azkaban.executor.selector;
import java.util.Comparator;
import org.apache.log4j.Logger;
/** wrapper class for a factor comparator .
*@param T: the type of the objects to be compared.
*/
public final class FactorComparator<T>{
private static Logger logger = Logger.getLogger(CandidateComparator.class);
private String factorName;
private int weight;
private Comparator<T> comparator;
/** private constructor of the class. User will create the instance of the class by calling the static
* method provided below.
* @param factorName : the factor name .
* @param weight : the weight of the comparator.
* @param comparator : function to be provided by user on how the comparison should be made.
* */
private FactorComparator(String factorName, int weight, Comparator<T> comparator){
this.factorName = factorName;
this.weight = weight;
this.comparator = comparator;
}
/** static function to generate an instance of the class.
* refer to the constructor for the param definitions.
* */
public static <T> FactorComparator<T> create(String factorName, int weight, Comparator<T> comparator){
if (null == factorName || factorName.length() == 0 || weight < 0 || null == comparator){
logger.error("failed to create instance of FactorComparator, at least one of the input paramters are invalid");
return null;
}
return new FactorComparator<T>(factorName,weight,comparator);
}
// function to return the factor name.
public String getFactorName(){
return this.factorName;
}
// function to return the weight value.
public int getWeight(){
return this.weight;
}
// function to return the weight value.
public void updateWeight(int value){
this.weight = value;
}
// the actual compare function, which will leverage the user defined function.
public int compare(T object1, T object2){
return this.comparator.compare(object1, object2);
}
}