1 files changed, 42 insertions, 0 deletions
diff --git a/core/src/main/scala/org/apache/spark/util/CompletionIterator.scala b/core/src/main/scala/org/apache/spark/util/CompletionIterator.scala
new file mode 100644
index 0000000000..dc15a38b29
--- /dev/null
+++ b/core/src/main/scala/org/apache/spark/util/CompletionIterator.scala
@@ -0,0 +1,42 @@
+/*
+ * 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 org.apache.spark.util
+
+/**
+ * Wrapper around an iterator which calls a completion method after it successfully iterates through all the elements
+ */
+abstract class CompletionIterator[+A, +I <: Iterator[A]](sub: I) extends Iterator[A]{
+  def next = sub.next
+  def hasNext = {
+    val r = sub.hasNext
+    if (!r) {
+      completion
+    }
+    r
+  }
+
+  def completion()
+}
+
+object CompletionIterator {
+  def apply[A, I <: Iterator[A]](sub: I, completionFunction: => Unit) : CompletionIterator[A,I] = {
+    new CompletionIterator[A,I](sub) {
+      def completion() = completionFunction
+    }
+  }
+}