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.malhar.contrib.redis;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.apex.malhar.lib.util.KeyValPair;
  
  /**
   * This is the an implementation of a Redis input operator for fetching
   * Key-Value pair stored in Redis. It takes in keys to fetch and emits
   * corresponding <Key, Value> Pair. Value data type is String in this case.
   *
   * @displayName Redis Input Operator for Key Value pair
   * @category Store
   * @tags input operator, key value
   *
   * @since 3.1.0
   */
  
  public class RedisKeyValueInputOperator extends AbstractRedisInputOperator<KeyValPair<String, String>>
  {
    private List<Object> keysObjectList = new ArrayList<Object>();
  
    @Override
    public void processTuples()
    {
      keysObjectList = new ArrayList<Object>(keys);
      if (keysObjectList.size() > 0) {
  
        List<Object> allValues = store.getAll(keysObjectList);
        for (int i = 0; i < allValues.size() && i < keys.size(); i++) {
          if (allValues.get(i) == null) {
            outputPort.emit(new KeyValPair<String, String>(keys.get(i), null));
          } else {
            outputPort.emit(new KeyValPair<String, String>(keys.get(i), allValues.get(i).toString()));
          }
        }
        keys.clear();
        keysObjectList.clear();
      }
    }
  
    @Override
    public KeyValPair<String, String> convertToTuple(Map<Object, Object> o)
    {
      // Do nothing for the override, Scan already done in processTuples
      return null;
    }
  }
  