[SPARK-23040][CORE][FOLLOW-UP] Avoid double wrap result Iterator.

## What changes were proposed in this pull request? Address apache#20449 (comment), If `resultIter` is already a `InterruptibleIterator`, don't double wrap it. ## How was this patch tested? Existing tests. Author: Xingbo Jiang <[email protected]> Closes apache#20920 from jiangxb1987/SPARK-23040.
jiangxb1987 · Mar 31, 2018 · e9a661f · e9a661f
1 parent cefb33f
commit e9a661f
Showing 1 changed file with 8 additions and 3 deletions.
diff --git a/core/src/main/scala/org/apache/spark/shuffle/BlockStoreShuffleReader.scala b/core/src/main/scala/org/apache/spark/shuffle/BlockStoreShuffleReader.scala
@@ -112,8 +112,13 @@ private[spark] class BlockStoreShuffleReader[K, C](
       case None =>
         aggregatedIter
     }
-    // Use another interruptible iterator here to support task cancellation as aggregator or(and)
-    // sorter may have consumed previous interruptible iterator.
-    new InterruptibleIterator[Product2[K, C]](context, resultIter)
+
+    resultIter match {
+      case _: InterruptibleIterator[Product2[K, C]] => resultIter
+      case _ =>
+        // Use another interruptible iterator here to support task cancellation as aggregator
+        // or(and) sorter may have consumed previous interruptible iterator.
+        new InterruptibleIterator[Product2[K, C]](context, resultIter)
+    }
   }
 }