Using Google Caliper with Scala - scala

Question

I am trying to use Caliper with Scala(2.10) in Eclipse Juno(4.2). For the start I've set up a benchmark that simply iterates a foreachloop over an array.
import com.google.caliper.Param
import com.google.caliper.SimpleBenchmark
class Benchmark extends SimpleBenchmark {
#Param(Array("10", "100", "1000", "10000"))
val length: Int = 0
var array: Array[Int] = _
override def setUp() {
array = new Array(length)
}
def timeForeach(reps: Int) = {
var result = 0
array.foreach {
result += _
}
result
}
When I start the benchmark with:
object myRunner {
def main(args: Array[String]) {
Runner.main(classOf[Benchmark], args)
}
}
I get these exceptions that I dont understand
0% Scenario{vm=java, trial=0, benchmark=Foreach, length=10} Failed to execute java -cp C:\Users\bob\workspace\myBenchmark\bin;C:\Users\bob\workspace\caliper\caliper\target>\classes;C:\Users\bob\workspace\caliper\caliper\target\test-classes;C:\Users\bob\.m2\repository\com\google\code\findbugs\jsr305\1.3.9\jsr305-1.3.9.jar;C:\Users\bob\.m2\repository\com\google\code\gson\gson\1.7.1\gson-1.7.1.jar;C:\Users\bob\.m2\repository\com\google\guava\guava\11.0.1\guava-11.0.1.jar;C:\Users\bob\.m2\repository\com\google\code\java-allocation-instrumenter\java-allocation-instrumenter\2.0\java-allocation-instrumenter-2.0.jar;C:\Users\bob\.m2\repository\asm\asm\3.3.1\asm-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-analysis\3.3.1\asm-analysis-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-commons\3.3.1\asm-commons-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-tree\3.3.1\asm-tree-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-util\3.3.1\asm-util-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-xml\3.3.1\asm-xml-3.3.1.jar;C:\Users\bob\.m2\repository\junit\junit\3.8.2\junit-3.8.2.jar com.google.caliper.InProcessRunner --warmupMillis 3000 --runMillis 1000 --measurementType TIME --marker //ZxJ/ -Dbenchmark=Foreach -Dlength=10 org.example.Benchmark
Exception in thread "main" java.lang.NoClassDefFoundError: scala/Function1
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.google.caliper.ScenarioSelection.getClassByName(ScenarioSelection.java:154)
at com.google.caliper.ScenarioSelection.prepareSuite(ScenarioSelection.java:123)
at com.google.caliper.ScenarioSelection.select(ScenarioSelection.java:83)
at com.google.caliper.InProcessRunner.run(InProcessRunner.java:38)
at com.google.caliper.InProcessRunner.main(InProcessRunner.java:103)
Caused by: java.lang.ClassNotFoundException: scala.Function1
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 7 more
An exception was thrown from the benchmark code.
com.google.caliper.ConfigurationException: Failed to execute java -cp C:\Users\bob\workspace\myBenchmark\bin;C:\Users\bob\workspace\caliper\caliper\target\classes;C:\Users\bob\workspace\caliper\caliper\target\test-classes;C:\Users\bob\.m2\repository\com\google\code\findbugs\jsr305\1.3.9\jsr305-1.3.9.jar;C:\Users\bob\.m2\repository\com\google\code\gson\gson\1.7.1\gson-1.7.1.jar;C:\Users\bob\.m2\repository\com\google\guava\guava\11.0.1\guava-11.0.1.jar;C:\Users\bob\.m2\repository\com\google\code\java-allocation-instrumenter\java-allocation-instrumenter\2.0\java-allocation-instrumenter-2.0.jar;C:\Users\bob\.m2\repository\asm\asm\3.3.1\asm-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-analysis\3.3.1\asm-analysis-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-commons\3.3.1\asm-commons-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-tree\3.3.1\asm-tree-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-util\3.3.1\asm-util-3.3.1.jar;C:\Users\bob\.m2\repository\asm\asm-xml\3.3.1\asm-xml-3.3.1.jar;C:\Users\bob\.m2\repository\junit\junit\3.8.2\junit-3.8.2.jar com.google.caliper.InProcessRunner --warmupMillis 3000 --runMillis 1000 --measurementType TIME --marker //ZxJ/ -Dbenchmark=Foreach -Dlength=10 org.example.Benchmark
at com.google.caliper.Runner.measure(Runner.java:309)
at com.google.caliper.Runner.runScenario(Runner.java:229)
at com.google.caliper.Runner.runOutOfProcess(Runner.java:378)
at com.google.caliper.Runner.run(Runner.java:97)
at com.google.caliper.Runner.main(Runner.java:423)
at com.google.caliper.Runner.main(Runner.java:436)
at org.example.myRunner$.main(myRunner.scala:7)
at org.example.myRunner.main(myRunner.scala)
I think I have some issues with the classpath but i am not sure.
I hope someone can help me :)
thanks in advance
Davram Bashere

Answer 1

It looks very much as though Caliper is running a new JVM and doesn't know that it needs to include the Scala libraries on the classpath.
This question describes how to run a Scala app with the java command on the command line. It should be a good starting point to solving this problem.

Answer 2

Even if you are editing scala sources in Eclipse you may still use sbt to run your code. Sbt is a great tool for managing your projects classpath in addition to providing a plugin system for providing the kinds of features like running Caliper benchmarks. I recently worked on a project where I needed just that and factored it out into an published sbt plugin. This may be of some help for you as well.

Answer 3

Thanks for your help. The problem was as expected the stupid classpath. I have downloaded the caliper project from googlecode and added the scala dependency. Now I've build my own jar-with-dependencies and it works quite fine.
Thanks for the answeres anyway :-)