/**
* 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.example.kddcup.track1;
import java.util.concurrent.Callable;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.mahout.cf.taste.common.NoSuchItemException;
import org.apache.mahout.cf.taste.common.TasteException;
import org.apache.mahout.cf.taste.model.PreferenceArray;
import org.apache.mahout.cf.taste.recommender.Recommender;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
final class Track1Callable implements Callable<byte[]> {
private static final Logger log = LoggerFactory.getLogger(Track1Callable.class);
private static final AtomicInteger COUNT = new AtomicInteger();
private final Recommender recommender;
private final PreferenceArray userTest;
Track1Callable(Recommender recommender, PreferenceArray userTest) {
this.recommender = recommender;
this.userTest = userTest;
}
@Override
public byte[] call() throws TasteException {
long userID = userTest.get(0).getUserID();
byte[] result = new byte[userTest.length()];
for (int i = 0; i < userTest.length(); i++) {
long itemID = userTest.getItemID(i);
double estimate;
try {
estimate = recommender.estimatePreference(userID, itemID);
} catch (NoSuchItemException nsie) {
// OK in the sample data provided before the contest, should never happen otherwise
log.warn("Unknown item {}; OK unless this is the real contest data", itemID);
continue;
}
result[i] = EstimateConverter.convert(estimate, userID, itemID);
}
if (COUNT.incrementAndGet() % 10000 == 0) {
log.info("Completed {} users", COUNT.get());
}
return result;
}
}