eu.stratosphere.api.scala.functions.JoinFunction.scala Maven / Gradle / Ivy

Go to download
/***********************************************************************************************************************
 * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
 *
 * 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 eu.stratosphere.api.scala.functions

import eu.stratosphere.api.java.record.functions.{JoinFunction => JJoinFunction}
import eu.stratosphere.api.scala.analysis.{UDTSerializer, UDF2, UDT}
import eu.stratosphere.types.Record
import eu.stratosphere.util.Collector

abstract class JoinFunctionBase[LeftIn: UDT, RightIn: UDT, Out: UDT] extends JJoinFunction with Serializable {
  val leftInputUDT = implicitly[UDT[LeftIn]]
  val rightInputUDT = implicitly[UDT[RightIn]]
  val outputUDT = implicitly[UDT[Out]]
  val udf: UDF2[LeftIn, RightIn, Out] = new UDF2(leftInputUDT, rightInputUDT, outputUDT)

  protected lazy val leftDeserializer: UDTSerializer[LeftIn] = udf.getLeftInputDeserializer
  protected lazy val leftDiscard: Array[Int] = udf.getLeftDiscardIndexArray.filter(_ < udf.getOutputLength)
  protected lazy val leftForwardFrom: Array[Int] = udf.getLeftForwardIndexArrayFrom
  protected lazy val leftForwardTo: Array[Int] = udf.getLeftForwardIndexArrayTo
  protected lazy val rightDeserializer: UDTSerializer[RightIn] = udf.getRightInputDeserializer
  protected lazy val rightForwardFrom: Array[Int] = udf.getRightForwardIndexArrayFrom
  protected lazy val rightForwardTo: Array[Int] = udf.getRightForwardIndexArrayTo
  protected lazy val serializer: UDTSerializer[Out] = udf.getOutputSerializer
  protected lazy val outputLength: Int = udf.getOutputLength
}

abstract class JoinFunction[LeftIn: UDT, RightIn: UDT, Out: UDT] extends JoinFunctionBase[LeftIn, RightIn, Out] with Function2[LeftIn, RightIn, Out] {
  override def `match`(leftRecord: Record, rightRecord: Record, out: Collector[Record]) = {
    val left = leftDeserializer.deserializeRecyclingOn(leftRecord)
    val right = rightDeserializer.deserializeRecyclingOn(rightRecord)
    val output = apply(left, right)

    leftRecord.setNumFields(outputLength)
    for (field <- leftDiscard)
      leftRecord.setNull(field)

    leftRecord.copyFrom(rightRecord, rightForwardFrom, rightForwardTo)
    leftRecord.copyFrom(leftRecord, leftForwardFrom, leftForwardTo)

    serializer.serialize(output, leftRecord)
    out.collect(leftRecord)
  }
}

abstract class FlatJoinFunction[LeftIn: UDT, RightIn: UDT, Out: UDT] extends JoinFunctionBase[LeftIn, RightIn, Out] with Function2[LeftIn, RightIn, Iterator[Out]] {
  override def `match`(leftRecord: Record, rightRecord: Record, out: Collector[Record]) = {
    val left = leftDeserializer.deserializeRecyclingOn(leftRecord)
    val right = rightDeserializer.deserializeRecyclingOn(rightRecord)
    val output = apply(left, right)

    if (output.nonEmpty) {

      leftRecord.setNumFields(outputLength)

      for (field <- leftDiscard)
        leftRecord.setNull(field)

      leftRecord.copyFrom(rightRecord, rightForwardFrom, rightForwardTo)
      leftRecord.copyFrom(leftRecord, leftForwardFrom, leftForwardTo)

      for (item <- output) {
        serializer.serialize(item, leftRecord)
        out.collect(leftRecord)
      }
    }
  }
}