Merge pull request #398 from pwendell/streaming-api

Rename DStream.foreach to DStream.foreachRDD

`foreachRDD` makes it clear that the granularity of this operator is per-RDD.
As it stands, `foreach` is inconsistent with with `map`, `filter`, and the other
DStream operators which get pushed down to individual records within each RDD.

4 files changed, 55 insertions, 18 deletions

diff --git a/streaming/src/main/scala/org/apache/spark/streaming/DStream.scala b/streaming/src/main/scala/org/apache/spark/streaming/DStream.scala
index b98f4a5101..9432a709d0 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/DStream.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/DStream.scala
@@ -17,19 +17,20 @@
 
 package org.apache.spark.streaming
 
-import StreamingContext._
-import org.apache.spark.streaming.dstream._
-import org.apache.spark.streaming.scheduler.Job
-import org.apache.spark.Logging
-import org.apache.spark.rdd.RDD
-import org.apache.spark.storage.StorageLevel
-import org.apache.spark.util.MetadataCleaner
+import java.io.{IOException, ObjectInputStream, ObjectOutputStream}
 
+import scala.deprecated
 import scala.collection.mutable.HashMap
 import scala.reflect.ClassTag
 
-import java.io.{ObjectInputStream, IOException, ObjectOutputStream}
+import StreamingContext._
 
+import org.apache.spark.Logging
+import org.apache.spark.rdd.RDD
+import org.apache.spark.storage.StorageLevel
+import org.apache.spark.streaming.dstream._
+import org.apache.spark.streaming.scheduler.Job
+import org.apache.spark.util.MetadataCleaner
 
 /**
  * A Discretized Stream (DStream), the basic abstraction in Spark Streaming, is a continuous
@@ -487,15 +488,29 @@ abstract class DStream[T: ClassTag] (
    * Apply a function to each RDD in this DStream. This is an output operator, so
    * 'this' DStream will be registered as an output stream and therefore materialized.
    */
-  def foreach(foreachFunc: RDD[T] => Unit) {
-    this.foreach((r: RDD[T], t: Time) => foreachFunc(r))
+  @deprecated("use foreachRDD", "0.9.0")
+  def foreach(foreachFunc: RDD[T] => Unit) = this.foreachRDD(foreachFunc)
+
+  /**
+   * Apply a function to each RDD in this DStream. This is an output operator, so
+   * 'this' DStream will be registered as an output stream and therefore materialized.
+   */
+  @deprecated("use foreachRDD", "0.9.0")
+  def foreach(foreachFunc: (RDD[T], Time) => Unit) = this.foreachRDD(foreachFunc)
+
+  /**
+   * Apply a function to each RDD in this DStream. This is an output operator, so
+   * 'this' DStream will be registered as an output stream and therefore materialized.
+   */
+  def foreachRDD(foreachFunc: RDD[T] => Unit) {
+    this.foreachRDD((r: RDD[T], t: Time) => foreachFunc(r))
   }
 
   /**
    * Apply a function to each RDD in this DStream. This is an output operator, so
    * 'this' DStream will be registered as an output stream and therefore materialized.
    */
-  def foreach(foreachFunc: (RDD[T], Time) => Unit) {
+  def foreachRDD(foreachFunc: (RDD[T], Time) => Unit) {
     ssc.registerOutputStream(new ForEachDStream(this, context.sparkContext.clean(foreachFunc)))
   }
 
@@ -719,7 +734,7 @@ abstract class DStream[T: ClassTag] (
       val file = rddToFileName(prefix, suffix, time)
       rdd.saveAsObjectFile(file)
     }
-    this.foreach(saveFunc)
+    this.foreachRDD(saveFunc)
   }
 
   /**
@@ -732,7 +747,7 @@ abstract class DStream[T: ClassTag] (
       val file = rddToFileName(prefix, suffix, time)
       rdd.saveAsTextFile(file)
     }
-    this.foreach(saveFunc)
+    this.foreachRDD(saveFunc)
   }
 
   def register() {
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/PairDStreamFunctions.scala b/streaming/src/main/scala/org/apache/spark/streaming/PairDStreamFunctions.scala
index 56dbcbda23..69d80c3711 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/PairDStreamFunctions.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/PairDStreamFunctions.scala
@@ -582,7 +582,7 @@ extends Serializable {
       val file = rddToFileName(prefix, suffix, time)
       rdd.saveAsHadoopFile(file, keyClass, valueClass, outputFormatClass, conf)
     }
-    self.foreach(saveFunc)
+    self.foreachRDD(saveFunc)
   }
 
   /**
@@ -612,7 +612,7 @@ extends Serializable {
       val file = rddToFileName(prefix, suffix, time)
       rdd.saveAsNewAPIHadoopFile(file, keyClass, valueClass, outputFormatClass, conf)
     }
-    self.foreach(saveFunc)
+    self.foreachRDD(saveFunc)
   }
 
   private def getKeyClass() = implicitly[ClassTag[K]].runtimeClass
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStreamLike.scala b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStreamLike.scala
index 64f38ce1c0..cea4795eb5 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStreamLike.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/api/java/JavaDStreamLike.scala
@@ -243,17 +243,39 @@ trait JavaDStreamLike[T, This <: JavaDStreamLike[T, This, R], R <: JavaRDDLike[T
   /**
    * Apply a function to each RDD in this DStream. This is an output operator, so
    * 'this' DStream will be registered as an output stream and therefore materialized.
+   *
+   * @deprecated  As of release 0.9.0, replaced by foreachRDD
    */
+  @Deprecated
   def foreach(foreachFunc: JFunction[R, Void]) {
-    dstream.foreach(rdd => foreachFunc.call(wrapRDD(rdd)))
+    foreachRDD(foreachFunc)
   }
 
   /**
    * Apply a function to each RDD in this DStream. This is an output operator, so
    * 'this' DStream will be registered as an output stream and therefore materialized.
+   *
+   * @deprecated  As of release 0.9.0, replaced by foreachRDD
    */
+  @Deprecated
   def foreach(foreachFunc: JFunction2[R, Time, Void]) {
-    dstream.foreach((rdd, time) => foreachFunc.call(wrapRDD(rdd), time))
+    foreachRDD(foreachFunc)
+  }
+
+  /**
+   * Apply a function to each RDD in this DStream. This is an output operator, so
+   * 'this' DStream will be registered as an output stream and therefore materialized.
+   */
+  def foreachRDD(foreachFunc: JFunction[R, Void]) {
+    dstream.foreachRDD(rdd => foreachFunc.call(wrapRDD(rdd)))
+  }
+
+  /**
+   * Apply a function to each RDD in this DStream. This is an output operator, so
+   * 'this' DStream will be registered as an output stream and therefore materialized.
+   */
+  def foreachRDD(foreachFunc: JFunction2[R, Time, Void]) {
+    dstream.foreachRDD((rdd, time) => foreachFunc.call(wrapRDD(rdd), time))
   }
 
   /**
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala
index ee6b433d1f..9a187ce031 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala
@@ -383,7 +383,7 @@ class BasicOperationsSuite extends TestSuiteBase {
     val input = Seq(Seq(1), Seq(2), Seq(3), Seq(4))
     val stream = new TestInputStream[Int](ssc, input, 2)
     ssc.registerInputStream(stream)
-    stream.foreach(_ => {})  // Dummy output stream
+    stream.foreachRDD(_ => {})  // Dummy output stream
     ssc.start()
     Thread.sleep(2000)
     def getInputFromSlice(fromMillis: Long, toMillis: Long) = {