org.apache.mahout.cf.taste.impl.neighborhood.AbstractUserNeighborhood Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.mahout.cf.taste.impl.neighborhood;
import java.util.Collection;
import org.apache.mahout.cf.taste.common.Refreshable;
import org.apache.mahout.cf.taste.impl.common.RefreshHelper;
import org.apache.mahout.cf.taste.model.DataModel;
import org.apache.mahout.cf.taste.neighborhood.UserNeighborhood;
import org.apache.mahout.cf.taste.similarity.UserSimilarity;
import com.google.common.base.Preconditions;
/**
*
* Contains methods and resources useful to all classes in this package.
*
*/
abstract class AbstractUserNeighborhood implements UserNeighborhood {
private final UserSimilarity userSimilarity;
private final DataModel dataModel;
private final double samplingRate;
private final RefreshHelper refreshHelper;
AbstractUserNeighborhood(UserSimilarity userSimilarity, DataModel dataModel, double samplingRate) {
Preconditions.checkArgument(userSimilarity != null, "userSimilarity is null");
Preconditions.checkArgument(dataModel != null, "dataModel is null");
Preconditions.checkArgument(samplingRate > 0.0 && samplingRate <= 1.0, "samplingRate must be in (0,1]");
this.userSimilarity = userSimilarity;
this.dataModel = dataModel;
this.samplingRate = samplingRate;
this.refreshHelper = new RefreshHelper(null);
this.refreshHelper.addDependency(this.dataModel);
this.refreshHelper.addDependency(this.userSimilarity);
}
final UserSimilarity getUserSimilarity() {
return userSimilarity;
}
final DataModel getDataModel() {
return dataModel;
}
final double getSamplingRate() {
return samplingRate;
}
@Override
public final void refresh(Collection alreadyRefreshed) {
refreshHelper.refresh(alreadyRefreshed);
}
}