content: /**
   * 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.apex.examples.machinedata.util;
  
  import java.util.Map;
  import java.util.Set;
  
  import javax.annotation.Nullable;
  
  import com.google.common.collect.Maps;
  
  /**
   * <p>DataTable class.</p>
   *
   * @since 0.3.5
   */
  public class DataTable<R,C,E>
  {
  
    //machineKey, [cpu,ram,hdd] -> value
    private final Map<R,Map<C,E>> table = Maps.newHashMap();
  
    public boolean containsRow(R rowKey)
    {
      return table.containsKey(rowKey);
    }
  
    public void put(R rowKey,C colKey, E entry)
    {
      if (!containsRow(rowKey)) {
        table.put(rowKey, Maps.<C,E>newHashMap());
      }
      table.get(rowKey).put(colKey, entry);
    }
  
    @Nullable
    public E get(R rowKey, C colKey)
    {
      if (!containsRow(rowKey)) {
        return null;
      }
      return table.get(rowKey).get(colKey);
    }
  
    public Set<R> rowKeySet()
    {
      return table.keySet();
    }
  
    public void clear()
    {
      table.clear();
    }
  
    public Map<R,Map<C,E>> getTable()
    {
      return table;
    }
  }
  