[SPARK-5333][Mesos] MesosTaskLaunchData occurs BufferUnderflowException

- Rewind ByteBuffer before making ByteString

(This fixes a bug introduced in apache#3849 / SPARK-4014)

Author: Jongyoul Lee <jongyoul@gmail.com>

Closes apache#4119 from jongyoul/SPARK-5333 and squashes the following commits:

c6693a8 [Jongyoul Lee] [SPARK-5333][Mesos] MesosTaskLaunchData occurs BufferUnderflowException - changed logDebug location
4141f58 [Jongyoul Lee] [SPARK-5333][Mesos] MesosTaskLaunchData occurs BufferUnderflowException - Added license information
2190606 [Jongyoul Lee] [SPARK-5333][Mesos] MesosTaskLaunchData occurs BufferUnderflowException - Adjusted imported libraries
b7f5517 [Jongyoul Lee] [SPARK-5333][Mesos] MesosTaskLaunchData occurs BufferUnderflowException - Rewind ByteBuffer before making ByteString

core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosTaskLaunchData.scala

@@ -21,24 +21,29 @@ import java.nio.ByteBuffer
 
 import org.apache.mesos.protobuf.ByteString
 
+import org.apache.spark.Logging
+
 /**
  * Wrapper for serializing the data sent when launching Mesos tasks.
  */
 private[spark] case class MesosTaskLaunchData(
   serializedTask: ByteBuffer,
-  attemptNumber: Int) {
+  attemptNumber: Int) extends Logging {
 
   def toByteString: ByteString = {
     val dataBuffer = ByteBuffer.allocate(4 + serializedTask.limit)
     dataBuffer.putInt(attemptNumber)
     dataBuffer.put(serializedTask)
+    dataBuffer.rewind
+    logDebug(s"ByteBuffer size: [${dataBuffer.remaining}]")
     ByteString.copyFrom(dataBuffer)
   }
 }
 
-private[spark] object MesosTaskLaunchData {
+private[spark] object MesosTaskLaunchData extends Logging {
   def fromByteString(byteString: ByteString): MesosTaskLaunchData = {
     val byteBuffer = byteString.asReadOnlyByteBuffer()
+    logDebug(s"ByteBuffer size: [${byteBuffer.remaining}]")
     val attemptNumber = byteBuffer.getInt // updates the position by 4 bytes
     val serializedTask = byteBuffer.slice() // subsequence starting at the current position
     MesosTaskLaunchData(serializedTask, attemptNumber)

core/src/test/scala/org/apache/spark/scheduler/mesos/MesosTaskLaunchDataSuite.scala

@@ -0,0 +1,38 @@
+/*
+ * 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.scheduler.mesos
+
+import java.nio.ByteBuffer
+
+import org.scalatest.FunSuite
+
+import org.apache.spark.scheduler.cluster.mesos.MesosTaskLaunchData
+
+class MesosTaskLaunchDataSuite extends FunSuite {
+  test("serialize and deserialize data must be same") {
+    val serializedTask = ByteBuffer.allocate(40)
+    (Range(100, 110).map(serializedTask.putInt(_)))
+    serializedTask.rewind
+    val attemptNumber = 100
+    val byteString = MesosTaskLaunchData(serializedTask, attemptNumber).toByteString
+    serializedTask.rewind
+    val mesosTaskLaunchData = MesosTaskLaunchData.fromByteString(byteString)
+    assert(mesosTaskLaunchData.attemptNumber == attemptNumber)
+    assert(mesosTaskLaunchData.serializedTask.equals(serializedTask))
+  }
+}