Capture BuildInfo when available

Author: Michael Armbrust <michael@databricks.com>

Closes #45 from marmbrus/buildInfo.

src/main/scala/com/databricks/spark/sql/perf/Benchmark.scala

@@ -16,14 +16,14 @@
 
 package com.databricks.spark.sql.perf
 
-import org.apache.spark.rdd.RDD
-
 import scala.collection.mutable
 import scala.collection.mutable.ArrayBuffer
 import scala.concurrent._
 import scala.concurrent.duration._
 import scala.concurrent.ExecutionContext.Implicits.global
+import scala.util.Try
 
+import org.apache.spark.rdd.RDD
 import org.apache.spark.sql.{Dataset, AnalysisException, DataFrame, SQLContext}
 import org.apache.spark.sql.catalyst.analysis.UnresolvedRelation
 import org.apache.spark.sql.execution.SparkPlan
@@ -54,10 +54,19 @@ abstract class Benchmark(
 
   protected implicit def toOption[A](a: A) = Option(a)
 
+  val buildInfo = Try(getClass.getClassLoader.loadClass("org.apache.spark.BuildInfo")).map { cls =>
+    cls.getMethods
+      .filter(_.getReturnType == classOf[String])
+        .filterNot(_.getName == "toString")
+        .map(m => m.getName -> m.invoke(cls).asInstanceOf[String])
+        .toMap
+  }.getOrElse(Map.empty)
+
   def currentConfiguration = BenchmarkConfiguration(
     sqlConf = sqlContext.getAllConfs,
     sparkConf = sparkContext.getConf.getAll.toMap,
-    defaultParallelism = sparkContext.defaultParallelism)
+    defaultParallelism = sparkContext.defaultParallelism,
+    buildInfo = buildInfo)
 
   /**
    * A Variation represents a setting (e.g. the number of shuffle partitions or if tables

src/main/scala/com/databricks/spark/sql/perf/results.scala

@@ -43,7 +43,8 @@ case class BenchmarkConfiguration(
     sparkVersion: String = org.apache.spark.SPARK_VERSION,
     sqlConf: Map[String, String],
     sparkConf: Map[String, String],
-    defaultParallelism: Int)
+    defaultParallelism: Int,
+    buildInfo: Map[String, String])
 
 /**
  * The result of a query.