adding full outer join support

core/src/main/scala/org/apache/spark/api/java/JavaPairRDD.scala

@@ -315,6 +315,19 @@ class JavaPairRDD[K, V](val rdd: RDD[(K, V)])(implicit val kManifest: ClassManif
     fromRDD(joinResult.mapValues{case (v, w) => (JavaUtils.optionToOptional(v), w)})
   }
 
+  /**
+   * Perform a full outer join of `this` and `other`. Output will have
+   * each row from both RDDs or `None` where missing, i.e. one of
+   * (k, (Some(v), Some(w)), (k, (Some(v), None)) or (k, (None, Some(w))
+   * depending on the presence of (k, v) and/or (k, w) in `this` and `other`
+   * Uses the given Partitioner to partition the output RDD.
+   */
+  def fullOuterJoin[W](other: JavaPairRDD[K, W], partitioner: Partitioner)
+  : JavaPairRDD[K, (Optional[V], Optional[W])] = {
+    val joinResult = rdd.fullOuterJoin(other, partitioner)
+    fromRDD(joinResult.mapValues{case (v, w) => (JavaUtils.optionToOptional(v), JavaUtils.optionToOptional(w))})
+  }
+
   /** 
    * Simplified version of combineByKey that hash-partitions the resulting RDD using the existing
    * partitioner/parallelism level.
@@ -404,6 +417,24 @@ class JavaPairRDD[K, V](val rdd: RDD[(K, V)])(implicit val kManifest: ClassManif
     fromRDD(joinResult.mapValues{case (v, w) => (JavaUtils.optionToOptional(v), w)})
   }
 
+  /**
+   * Perform a full outer join of `this` and `other`. Hash-partitions the resulting
+   * RDD using the existing partitioner/parallelism level.
+   */
+  def fullOuterJoin[W](other: JavaPairRDD[K, W]): JavaPairRDD[K, (Optional[V], Optional[W])] = {
+    val joinResult = rdd.fullOuterJoin(other)
+    fromRDD(joinResult.mapValues{case (v, w) => (JavaUtils.optionToOptional(v), JavaUtils.optionToOptional(w))})
+  }
+
+  /**
+   * Perform a full outer join of `this` and `other`. Hash-partitions the resulting
+   * RDD into the given number of partitions.
+   */
+  def fullOuterJoin[W](other: JavaPairRDD[K, W], numPartitions: Int): JavaPairRDD[K, (Optional[V], Optional[W])] = {
+    val joinResult = rdd.fullOuterJoin(other, numPartitions)
+    fromRDD(joinResult.mapValues{case (v, w) => (JavaUtils.optionToOptional(v), JavaUtils.optionToOptional(w))})
+  }
+
   /**
    * Return the key-value pairs in this RDD to the master as a Map.
    */

core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala

@@ -292,6 +292,26 @@ class PairRDDFunctions[K: ClassManifest, V: ClassManifest](self: RDD[(K, V)])
     }
   }
 
+  /**
+   * Perform a full outer join of `this` and `other`. Output will have
+   * each row from both RDDs or `None` where missing, i.e. one of
+   * (k, (Some(v), Some(w)), (k, (Some(v), None)) or (k, (None, Some(w))
+   * depending on the presence of (k, v) and/or (k, w) in `this` and `other`
+   * Uses the given Partitioner to partition the output RDD.
+   */
+  def fullOuterJoin[W](other: RDD[(K, W)], partitioner: Partitioner)
+      : RDD[(K, (Option[V], Option[W]))] = {
+    this.cogroup(other, partitioner).flatMapValues { case (vs, ws) =>
+      if (vs.isEmpty && !ws.isEmpty) {
+        ws.iterator.map(w => (None, Some(w)))
+      } else if (ws.isEmpty && !vs.isEmpty) {
+        vs.iterator.map(v => (Some(v), None))
+      } else {
+        for (v <- vs.iterator; w <- ws.iterator) yield (Some(v), Some(w))
+      }
+    }
+  }
+
   /**
    * Simplified version of combineByKey that hash-partitions the resulting RDD using the
    * existing partitioner/parallelism level.
@@ -377,6 +397,22 @@ class PairRDDFunctions[K: ClassManifest, V: ClassManifest](self: RDD[(K, V)])
     rightOuterJoin(other, new HashPartitioner(numPartitions))
   }
 
+  /**
+   * Perform a full outer join of `this` and `other`. Hash-partitions the resulting
+   * RDD using the existing partitioner/parallelism level.
+   */
+  def fullOuterJoin[W](other: RDD[(K, W)]): RDD[(K, (Option[V], Option[W]))] = {
+    fullOuterJoin(other, defaultPartitioner(self, other))
+  }
+
+  /**
+   * Perform a full outer join of `this` and `other`. Hash-partitions the resulting
+   * RDD into the given number of partitions.
+   */
+  def fullOuterJoin[W](other: RDD[(K, W)], numPartitions: Int): RDD[(K, (Option[V], Option[W]))] = {
+    fullOuterJoin(other, new HashPartitioner(numPartitions))
+  }
+
   /**
    * Return the key-value pairs in this RDD to the master as a Map.
    */

core/src/test/scala/org/apache/spark/PartitioningSuite.scala

@@ -102,11 +102,13 @@ class PartitioningSuite extends FunSuite with SharedSparkContext {
     assert(grouped2.join(grouped4).partitioner === grouped4.partitioner)
     assert(grouped2.leftOuterJoin(grouped4).partitioner === grouped4.partitioner)
     assert(grouped2.rightOuterJoin(grouped4).partitioner === grouped4.partitioner)
+    assert(grouped2.fullOuterJoin(grouped4).partitioner === grouped4.partitioner)
     assert(grouped2.cogroup(grouped4).partitioner === grouped4.partitioner)
 
     assert(grouped2.join(reduced2).partitioner === grouped2.partitioner)
     assert(grouped2.leftOuterJoin(reduced2).partitioner === grouped2.partitioner)
     assert(grouped2.rightOuterJoin(reduced2).partitioner === grouped2.partitioner)
+    assert(grouped2.fullOuterJoin(reduced2).partitioner === grouped2.partitioner)
     assert(grouped2.cogroup(reduced2).partitioner === grouped2.partitioner)
 
     assert(grouped2.map(_ => 1).partitioner === None)
@@ -127,6 +129,7 @@ class PartitioningSuite extends FunSuite with SharedSparkContext {
     assert(intercept[SparkException]{ arrPairs.join(arrPairs) }.getMessage.contains("array"))
     assert(intercept[SparkException]{ arrPairs.leftOuterJoin(arrPairs) }.getMessage.contains("array"))
     assert(intercept[SparkException]{ arrPairs.rightOuterJoin(arrPairs) }.getMessage.contains("array"))
+    assert(intercept[SparkException]{ arrPairs.fullOuterJoin(arrPairs) }.getMessage.contains("array"))
     assert(intercept[SparkException]{ arrPairs.groupByKey() }.getMessage.contains("array"))
     assert(intercept[SparkException]{ arrPairs.countByKey() }.getMessage.contains("array"))
     assert(intercept[SparkException]{ arrPairs.countByKeyApprox(1) }.getMessage.contains("array"))

core/src/test/scala/org/apache/spark/rdd/PairRDDFunctionsSuite.scala

@@ -165,6 +165,21 @@ class PairRDDFunctionsSuite extends FunSuite with SharedSparkContext {
     ))
   }
 
+  test("fullOuterJoin") {
+    val rdd1 = sc.parallelize(Array((1, 1), (1, 2), (2, 1), (3, 1)))
+    val rdd2 = sc.parallelize(Array((1, 'x'), (2, 'y'), (2, 'z'), (4, 'w')))
+    val joined = rdd1.fullOuterJoin(rdd2).collect()
+    assert(joined.size === 6)
+    assert(joined.toSet === Set(
+      (1, (Some(1), Some('x'))),
+      (1, (Some(2), Some('x'))),
+      (2, (Some(1), Some('y'))),
+      (2, (Some(1), Some('z'))),
+      (3, (Some(1), None)),
+      (4, (None, Some('w')))
+    ))
+  }
+
   test("join with no matches") {
     val rdd1 = sc.parallelize(Array((1, 1), (1, 2), (2, 1), (3, 1)))
     val rdd2 = sc.parallelize(Array((4, 'x'), (5, 'y'), (5, 'z'), (6, 'w')))

core/src/test/scala/org/apache/spark/rdd/RDDSuite.scala

@@ -135,6 +135,7 @@ class RDDSuite extends FunSuite with SharedSparkContext {
     assert(rdd.join(emptyKv).collect().size === 0)
     assert(rdd.rightOuterJoin(emptyKv).collect().size === 0)
     assert(rdd.leftOuterJoin(emptyKv).collect().size === 2)
+    assert(rdd.fullOuterJoin(emptyKv).collect().size === 2)
     assert(rdd.cogroup(emptyKv).collect().size === 2)
     assert(rdd.union(emptyKv).collect().size === 2)
   }

python/pyspark/join.py

@@ -78,6 +78,22 @@ def dispatch(seq):
     return _do_python_join(rdd, other, numPartitions, dispatch)
 
 
+def python_full_outer_join(rdd, other, numPartitions):
+    def dispatch(seq):
+        vbuf, wbuf = [], []
+        for (n, v) in seq:
+            if n == 1:
+                vbuf.append(v)
+            elif n == 2:
+                wbuf.append(v)
+        if not vbuf:
+            vbuf.append(None)
+        if not wbuf:
+            wbuf.append(None)
+        return [(v, w) for v in vbuf for w in wbuf]
+    return _do_python_join(rdd, other, numPartitions, dispatch)
+
+
 def python_cogroup(rdd, other, numPartitions):
     vs = rdd.map(lambda (k, v): (k, (1, v)))
     ws = other.map(lambda (k, v): (k, (2, v)))

python/pyspark/rdd.py

@@ -728,6 +728,23 @@ def rightOuterJoin(self, other, numPartitions=None):
         """
         return python_right_outer_join(self, other, numPartitions)
 
+    def fullOuterJoin(self, other, numPartitions=None):
+        """
+        Perform a full outer join of C{self} and C{other}.
+
+        Output will have each row from both RDDs or None where missing, i.e.
+        one of (k, (v, w)), (k, (v, None)), or (k, (None, w)) depending on
+        the presence of (k, v) and/or (k, w) in C{self} and C{other}
+
+        Hash-partitions the resulting RDD into the given number of partitions.
+
+        >>> x = sc.parallelize([("a", 1), ("b", 4)])
+        >>> y = sc.parallelize([("a", 2)])
+        >>> sorted(y.fullOuterJoin(x).collect())
+        [('a', (2, 1)), ('b', (None, 4))]
+        """
+        return python_full_outer_join(self, other, numPartitions)
+
     # TODO: add option to control map-side combining
     def partitionBy(self, numPartitions, partitionFunc=hash):
         """

streaming/src/main/scala/org/apache/spark/streaming/PairDStreamFunctions.scala

@@ -549,6 +549,42 @@ extends Serializable {
     )
   }
 
+  /**
+   * Return a new DStream by applying 'full outer join' between RDDs of `this` DStream and
+   * `other` DStream. Hash partitioning is used to generate the RDDs with Spark's default
+   * number of partitions.
+   */
+  def fullOuterJoin[W: ClassManifest](other: DStream[(K, W)]): DStream[(K, (Option[V], Option[W]))] = {
+    fullOuterJoin[W](other, defaultPartitioner())
+  }
+
+  /**
+   * Return a new DStream by applying 'full outer join' between RDDs of `this` DStream and
+   * `other` DStream. Hash partitioning is used to generate the RDDs with `numPartitions`
+   * partitions.
+   */
+  def fullOuterJoin[W: ClassManifest](
+      other: DStream[(K, W)],
+      numPartitions: Int
+    ): DStream[(K, (Option[V], Option[W]))] = {
+    fullOuterJoin[W](other, defaultPartitioner(numPartitions))
+  }
+
+  /**
+   * Return a new DStream by applying 'full outer join' between RDDs of `this` DStream and
+   * `other` DStream. The supplied [[org.apache.spark.Partitioner]] is used to control
+   * the partitioning of each RDD.
+   */
+  def fullOuterJoin[W: ClassManifest](
+      other: DStream[(K, W)],
+      partitioner: Partitioner
+    ): DStream[(K, (Option[V], Option[W]))] = {
+    self.transformWith(
+      other,
+      (rdd1: RDD[(K, V)], rdd2: RDD[(K, W)]) => rdd1.fullOuterJoin(rdd2, partitioner)
+    )
+  }
+
   /**
    * Save each RDD in `this` DStream as a Hadoop file. The file name at each batch interval
    * is generated based on `prefix` and `suffix`: "prefix-TIME_IN_MS.suffix"

streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaPairDStream.scala

@@ -647,6 +647,48 @@ class JavaPairDStream[K, V](val dstream: DStream[(K, V)])(
     joinResult.mapValues{case (v, w) => (JavaUtils.optionToOptional(v), w)}
   }
 
+  /**
+   * Return a new DStream by applying 'full outer join' between RDDs of `this` DStream and
+   * `other` DStream. Hash partitioning is used to generate the RDDs with Spark's default
+   * number of partitions.
+   */
+  def fullOuterJoin[W](other: JavaPairDStream[K, W]): JavaPairDStream[K, (Optional[V], Optional[W])] = {
+    implicit val cm: ClassManifest[W] =
+      implicitly[ClassManifest[AnyRef]].asInstanceOf[ClassManifest[W]]
+    val joinResult = dstream.fullOuterJoin(other.dstream)
+    joinResult.mapValues{case (v, w) => (JavaUtils.optionToOptional(v), JavaUtils.optionToOptional(w))}
+  }
+
+  /**
+   * Return a new DStream by applying 'full outer join' between RDDs of `this` DStream and
+   * `other` DStream. Hash partitioning is used to generate the RDDs with `numPartitions`
+   * partitions.
+   */
+  def fullOuterJoin[W](
+      other: JavaPairDStream[K, W],
+      numPartitions: Int
+    ): JavaPairDStream[K, (Optional[V], Optional[W])] = {
+    implicit val cm: ClassManifest[W] =
+      implicitly[ClassManifest[AnyRef]].asInstanceOf[ClassManifest[W]]
+    val joinResult = dstream.fullOuterJoin(other.dstream, numPartitions)
+    joinResult.mapValues{case (v, w) => (JavaUtils.optionToOptional(v), JavaUtils.optionToOptional(w))}
+  }
+
+  /**
+   * Return a new DStream by applying 'full outer join' between RDDs of `this` DStream and
+   * `other` DStream. The supplied [[org.apache.spark.Partitioner]] is used to control
+   * the partitioning of each RDD.
+   */
+  def fullOuterJoin[W](
+      other: JavaPairDStream[K, W],
+      partitioner: Partitioner
+    ): JavaPairDStream[K, (Optional[V], Optional[W])] = {
+    implicit val cm: ClassManifest[W] =
+      implicitly[ClassManifest[AnyRef]].asInstanceOf[ClassManifest[W]]
+    val joinResult = dstream.fullOuterJoin(other.dstream, partitioner)
+    joinResult.mapValues{case (v, w) => (JavaUtils.optionToOptional(v), JavaUtils.optionToOptional(w))}
+  }
+
   /**
    * Save each RDD in `this` DStream as a Hadoop file. The file name at each batch interval is
    * generated based on `prefix` and `suffix`: "prefix-TIME_IN_MS.suffix".

streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala

@@ -310,6 +310,21 @@ class BasicOperationsSuite extends TestSuiteBase {
     testOperation(inputData1, inputData2, operation, outputData, true)
   }
 
+  test("fullOuterJoin") {
+    val inputData1 = Seq( Seq("a", "b"), Seq("a", ""), Seq(""), Seq() )
+    val inputData2 = Seq( Seq("a", "b"), Seq("b", ""), Seq(), Seq("")   )
+    val outputData = Seq(
+      Seq( ("a", (Some(1), Some("x"))), ("b", (Some(1), Some("x"))) ),
+      Seq( ("", (Some(1), Some("x"))), ("b", (None, Some("x"))), ("a", (Some(1), None)) ),
+      Seq( ("", (Some(1), None)) ),
+      Seq( ("", (None, Some("x"))) )
+    )
+    val operation = (s1: DStream[String], s2: DStream[String]) => {
+      s1.map(x => (x, 1)).fullOuterJoin(s2.map(x => (x, "x")))
+    }
+    testOperation(inputData1, inputData2, operation, outputData, true)
+  }
+
   test("updateStateByKey") {
     val inputData =
       Seq(