/*
 * 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.texera.amber.operator.map

import org.apache.texera.amber.core.executor.OperatorExecutor
import org.apache.texera.amber.core.tuple.{Tuple, TupleLike}

/**
  * Common operator executor of a map() function
  * A map() function transforms one input tuple to exactly one output tuple.
  */
abstract class MapOpExec extends OperatorExecutor with Serializable {

  private var mapFunc: Tuple => TupleLike = _

  /**
    * Provides the flatMap function of this executor, it should be called in the constructor
    * If the operator executor is implemented in Java, it should be called with:
    * setMapFunc((Function1<Tuple, TupleLike> & Serializable) func)
    */
  def setMapFunc(func: Tuple => TupleLike): Unit = mapFunc = func

  override def processTuple(tuple: Tuple, port: Int): Iterator[TupleLike] = Iterator(mapFunc(tuple))

}
