aboutsummaryrefslogtreecommitdiff
path: root/streaming/src/main/scala/spark/streaming/dstream/CoGroupedDStream.scala
blob: 99553d295d55b168694947e5a49f4ca02dc9d58a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
/*
 * 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 spark.streaming.dstream

import spark.{RDD, Partitioner}
import spark.rdd.CoGroupedRDD
import spark.streaming.{Time, DStream, Duration}

private[streaming]
class CoGroupedDStream[K : ClassManifest](
    parents: Seq[DStream[(K, _)]],
    partitioner: Partitioner
  ) extends DStream[(K, Seq[Seq[_]])](parents.head.ssc) {

  if (parents.length == 0) {
    throw new IllegalArgumentException("Empty array of parents")
  }

  if (parents.map(_.ssc).distinct.size > 1) {
    throw new IllegalArgumentException("Array of parents have different StreamingContexts")
  }

  if (parents.map(_.slideDuration).distinct.size > 1) {
    throw new IllegalArgumentException("Array of parents have different slide times")
  }

  override def dependencies = parents.toList

  override def slideDuration: Duration = parents.head.slideDuration

  override def compute(validTime: Time): Option[RDD[(K, Seq[Seq[_]])]] = {
    val part = partitioner
    val rdds = parents.flatMap(_.getOrCompute(validTime))
    if (rdds.size > 0) {
      val q = new CoGroupedRDD[K](rdds, part)
      Some(q)
    } else {
      None
    }
  }

}