Avoid Option while generating call site

This is an update on https://github.com/apache/spark/pull/180, which changes the solution from blacklisting "Option.scala" to avoiding the Option code path while generating the call path.

Also includes a unit test to prevent this issue in the future, and some minor refactoring.

Thanks @witgo for reporting this issue and working on the initial solution!

Author: witgo <witgo@qq.com>
Author: Aaron Davidson <aaron@databricks.com>

Closes #222 from aarondav/180 and squashes the following commits:

f74aad1 [Aaron Davidson] Avoid Option while generating call site & add unit tests
d2b4980 [witgo] Modify the position of the filter
1bc22d7 [witgo] Fix Stage.name return "apply at Option.scala:120"

core/src/main/scala/org/apache/spark/SparkContext.scala

@@ -877,7 +877,8 @@ class SparkContext(
    * has overridden the call site, this will return the user's version.
    */
   private[spark] def getCallSite(): String = {
-    Option(getLocalProperty("externalCallSite")).getOrElse(Utils.formatCallSiteInfo())
+    val defaultCallSite = Utils.getCallSiteInfo
+    Option(getLocalProperty("externalCallSite")).getOrElse(defaultCallSite.toString)
   }
 
   /**

core/src/main/scala/org/apache/spark/rdd/RDD.scala

@@ -1041,7 +1041,7 @@ abstract class RDD[T: ClassTag](
 
   /** User code that created this RDD (e.g. `textFile`, `parallelize`). */
   @transient private[spark] val creationSiteInfo = Utils.getCallSiteInfo
-  private[spark] def getCreationSite = Utils.formatCallSiteInfo(creationSiteInfo)
+  private[spark] def getCreationSite: String = creationSiteInfo.toString
 
   private[spark] def elementClassTag: ClassTag[T] = classTag[T]
 

core/src/main/scala/org/apache/spark/util/Utils.scala

@@ -679,7 +679,13 @@ private[spark] object Utils extends Logging {
   private val SPARK_CLASS_REGEX = """^org\.apache\.spark(\.api\.java)?(\.util)?(\.rdd)?\.[A-Z]""".r
 
   private[spark] class CallSiteInfo(val lastSparkMethod: String, val firstUserFile: String,
-                                    val firstUserLine: Int, val firstUserClass: String)
+                                    val firstUserLine: Int, val firstUserClass: String) {
+
+    /** Returns a printable version of the call site info suitable for logs. */
+    override def toString = {
+      "%s at %s:%s".format(lastSparkMethod, firstUserFile, firstUserLine)
+    }
+  }
 
   /**
    * When called inside a class in the spark package, returns the name of the user code class
@@ -687,8 +693,8 @@ private[spark] object Utils extends Logging {
    * This is used, for example, to tell users where in their code each RDD got created.
    */
   def getCallSiteInfo: CallSiteInfo = {
-    val trace = Thread.currentThread.getStackTrace().filter( el =>
-      (!el.getMethodName.contains("getStackTrace")))
+    val trace = Thread.currentThread.getStackTrace()
+      .filterNot(_.getMethodName.contains("getStackTrace"))
 
     // Keep crawling up the stack trace until we find the first function not inside of the spark
     // package. We track the last (shallowest) contiguous Spark method. This might be an RDD
@@ -721,12 +727,6 @@ private[spark] object Utils extends Logging {
     new CallSiteInfo(lastSparkMethod, firstUserFile, firstUserLine, firstUserClass)
   }
 
-  /** Returns a printable version of the call site info suitable for logs. */
-  def formatCallSiteInfo(callSiteInfo: CallSiteInfo = Utils.getCallSiteInfo) = {
-    "%s at %s:%s".format(callSiteInfo.lastSparkMethod, callSiteInfo.firstUserFile,
-                         callSiteInfo.firstUserLine)
-  }
-
   /** Return a string containing part of a file from byte 'start' to 'end'. */
   def offsetBytes(path: String, start: Long, end: Long): String = {
     val file = new File(path)

core/src/test/scala/org/apache/spark/SparkContextInfoSuite.scala

@@ -17,7 +17,7 @@
 
 package org.apache.spark
 
-import org.scalatest.FunSuite
+import org.scalatest.{Assertions, FunSuite}
 
 class SparkContextInfoSuite extends FunSuite with LocalSparkContext {
   test("getPersistentRDDs only returns RDDs that are marked as cached") {
@@ -56,4 +56,38 @@ class SparkContextInfoSuite extends FunSuite with LocalSparkContext {
     rdd.collect()
     assert(sc.getRDDStorageInfo.size === 1)
   }
+
+  test("call sites report correct locations") {
+    sc = new SparkContext("local", "test")
+    testPackage.runCallSiteTest(sc)
+  }
+}
+
+/** Call site must be outside of usual org.apache.spark packages (see Utils#SPARK_CLASS_REGEX). */
+package object testPackage extends Assertions {
+  private val CALL_SITE_REGEX = "(.+) at (.+):([0-9]+)".r
+
+  def runCallSiteTest(sc: SparkContext) {
+    val rdd = sc.makeRDD(Array(1, 2, 3, 4), 2)
+    val rddCreationSite = rdd.getCreationSite
+    val curCallSite = sc.getCallSite() // note: 2 lines after definition of "rdd"
+
+    val rddCreationLine = rddCreationSite match {
+      case CALL_SITE_REGEX(func, file, line) => {
+        assert(func === "makeRDD")
+        assert(file === "SparkContextInfoSuite.scala")
+        line.toInt
+      }
+      case _ => fail("Did not match expected call site format")
+    }
+
+    curCallSite match {
+      case CALL_SITE_REGEX(func, file, line) => {
+        assert(func === "getCallSite") // this is correct because we called it from outside of Spark
+        assert(file === "SparkContextInfoSuite.scala")
+        assert(line.toInt === rddCreationLine.toInt + 2)
+      }
+      case _ => fail("Did not match expected call site format")
+    }
+  }
 }