code: /*
   * Copyright 2017 recommenders.net.
   *
   * 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 net.recommenders.rival.recommend.frameworks.ranksys;
  
  import es.uam.eps.ir.ranksys.fast.index.FastUserIndex;
  import es.uam.eps.ir.ranksys.fast.index.SimpleFastUserIndex;
  import java.util.HashSet;
  import java.util.Set;
  import java.util.stream.Stream;
  import net.recommenders.rival.core.TemporalDataModelIF;
  
  /**
   *
   * @author Alejandro
   */
  public class UserIndexWrapper implements FastUserIndex<Long> {
  
      private final FastUserIndex<Long> wrapper;
  
      public UserIndexWrapper(TemporalDataModelIF<Long, Long> training, TemporalDataModelIF<Long, Long> test) {
          Set<Long> users = new HashSet<>();
          for (Long u : training.getUsers()) {
              users.add(u);
          }
          for (Long u : test.getUsers()) {
              users.add(u);
          }
          wrapper = SimpleFastUserIndex.load(users.stream());
      }
  
      @Override
      public int user2uidx(Long u) {
          return wrapper.user2uidx(u);
      }
  
      @Override
      public Long uidx2user(int uidx) {
          return wrapper.uidx2user(uidx);
      }
  
      @Override
      public boolean containsUser(Long u) {
          return wrapper.containsUser(u);
      }
  
      @Override
      public int numUsers() {
          return wrapper.numUsers();
      }
  
      @Override
      public Stream<Long> getAllUsers() {
          return wrapper.getAllUsers();
      }
  
  }
  