add case for when no records are present in the file

* updated PAR1_END to \0PAR1, not all parquet files are written
  with \0\0PAR1

src/main/scala/ParquetDumper.scala

@@ -76,7 +76,7 @@ class StdinUnpacker(printerActor: ActorRef) extends Actor with akka.actor.ActorL
       var numParOnes = 1
       var sawParquetMrVersion = false
       val PAR1_BEG = scala.collection.mutable.Queue("PAR1".toList.map(_.toByte): _*)
-      val PAR1_END = scala.collection.mutable.Queue[Byte](0.toByte, 0.toByte) ++ PAR1_BEG
+      val PAR1_END = scala.collection.mutable.Queue[Byte](0.toByte) ++ PAR1_BEG
       var PARQUET_MR_VERSION = "parquet-mr version".toList.map(_.toByte).toVector
       val q = scala.collection.mutable.Queue[Byte]()
 
@@ -168,6 +168,10 @@ class ParquetReaderActor(printerActor: ActorRef) extends Actor with akka.actor.A
         linesSent += 1
         record = reader.read()
       }
+      // special case where the parquet file is empty
+      if (linesSent == 0) {
+        context.parent.tell(ParquetReaderFinished, self)
+      }
       new java.io.File(input).delete
     }
   }