/*
* 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.Collection;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.log4j.Logger;
/** Abstract class for a candidate filter.
* this class contains implementation of most of the core logics. Implementing classes is expected only to
* register filters using the provided register function.
*/
public abstract class CandidateFilter<T,V> {
protected static Logger logger = Logger.getLogger(CandidateFilter.class);
// internal repository of the registered filters .
private Map<String,FactorFilter<T,V>> factorFilterList =
new ConcurrentHashMap<String,FactorFilter<T,V>>();
/** gets the name of the current implementation of the candidate filter.
* @return : name of the filter.
* */
public abstract String getName();
/** function to register a factorFilter to the internal Map for future reference.
* @param factorfilter : the Filter object to be registered.
* @throws IllegalArgumentException
* */
protected void registerFactorFilter(FactorFilter<T,V> filter){
if (null == filter ) {
throw new IllegalArgumentException("unable to register factor filter. " +
"The passed comaractor is null or has an invalid weight value.");
}
// add or replace the filter.
this.factorFilterList.put(filter.getFactorName(),filter);
logger.debug(String.format("Factor filter added for '%s'.",
filter.getFactorName()));
}
/** 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.
* */
public boolean filterTarget(T filteringTarget, V referencingObject){
logger.debug(String.format("start filtering '%s' with factor filter for '%s'",
filteringTarget == null ? "(null)" : filteringTarget.toString(),
this.getName()));
Collection<FactorFilter<T,V>> filterList = this.factorFilterList.values();
boolean result = true;
for (FactorFilter<T,V> filter : filterList){
result &= filter.filterTarget(filteringTarget,referencingObject);
logger.debug(String.format("[Factor: %s] filter result : %s ",
filter.getFactorName(), result));
if (!result){
break;
}
}
logger.debug(String.format("Final filtering result : %s ",result));
return result;
}
}