/*
* 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 org.apache.log4j.Logger;
/** wrapper class for a factor Filter .
*@param T: the type of the objects to be compared.
*@param V: the type of the object to be used for filtering.
*/
public final class FactorFilter<T,V>{
private static Logger logger = Logger.getLogger(FactorFilter.class);
private String factorName;
private Filter<T,V> filter;
/** 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 filter : user defined function specifying how the filtering should be implemented.
* */
private FactorFilter(String factorName, Filter<T,V> filter){
this.factorName = factorName;
this.filter = filter;
}
/** static function to generate an instance of the class.
* refer to the constructor for the param definitions.
* */
public static <T,V> FactorFilter<T,V> create(String factorName, Filter<T,V> filter){
if (null == factorName || factorName.length() == 0 || null == filter){
logger.error("failed to create instance of FactorFilter, at least one of the input paramters are invalid");
return null;
}
return new FactorFilter<T,V>(factorName,filter);
}
// function to return the factor name.
public String getFactorName(){
return this.factorName;
}
// the actual check function, which will leverage the logic defined by user.
public boolean filterTarget(T filteringTarget, V referencingObject){
return this.filter.filterTarget(filteringTarget, referencingObject);
}
// interface of the filter.
public interface Filter<T,V>{
/**function to analyze the target item according to the reference object to decide whether the item should be filtered.
* @param filteringTarget object to be checked.
* @param referencingObject object which contains statistics based on which a decision is made whether
* the object being checked need to be filtered or not.
* @return true if the check passed, false if check failed, which means the item need to be filtered.
* */
boolean filterTarget(T filteringTarget, V referencingObject);
}
}