perf test for explicitly checking isDebugEnabled vs passing a closure

LogPerfTest.scala

import org.apache.log4j.{Logger, Level}

object LogPerfTest {

  val logger = Logger.getLogger(this.getClass)

  def main(args: Array[String]) {
    val stmt = "This is a test log statement"
    var iterations = args(0).toInt

    for(logLevel <- List(Level.DEBUG, Level.INFO)) {
      var i = 0
      logger.setLevel(logLevel)
      var start = System.nanoTime
      while(i < iterations) {
        if(logger.isDebugEnabled)
          logger.debug(stmt)
        i += 1
      }
      var ellapsed: Double = System.nanoTime - start
      System.err.println("ifDebugEnabled with logging = " + logLevel + ": " + (ellapsed / iterations) + " ns per invocation")
      System.err.flush()

      i = 0
      start = System.nanoTime
      while(i < iterations) {
        debug(stmt)
        i += 1
      }
      ellapsed = System.nanoTime - start
      System.err.println("Debug helper with logging = " + logLevel + ": " + (ellapsed / iterations) + " ns per invocation")
      System.err.flush()
    }

  }

  def debug(stmt: => String) = 
    if(logger.isDebugEnabled)
      logger.debug(stmt)
}