Junk — dummy profiler

gistfile1.java

package scala.tools.nsc

object Junk {
    def currentTimeMicros = System.nanoTime / 1000
    
    case class Current(stack: List[String], start: Long)
    var current: Option[Current] = None
    
    val map = new scala.collection.mutable.HashMap[String, Long]
    
    private def updateCurrent() {
        if (current.isDefined) {
            val now = currentTimeMicros
            val d = currentTimeMicros - current.get.start
            val name = current.get.stack.head
            map.get(name) match {
                case Some(micros) => map.update(name, micros + d)
                case None => map.update(name, d)
            }
        }
    }
    
    private val enable = true
    
    def now(name: String) = if (enable) {
        updateCurrent()
        current = Some(Current(name :: (current.map(_.stack).getOrElse(Nil)), currentTimeMicros))
    }
    
    def pop() = if (enable) {
        require(current.isDefined)
        updateCurrent()
        current.get.stack match {
            case _ :: Nil => current = None
            case first :: rest => current = Some(Current(rest, currentTimeMicros))
        }
    }
    
    def change(name: String) = {
        pop()
        now(name)
    }
    
    def enter[T](name: String)(t: => T) =
        try {
            now(name)
            t
        } finally {
            pop()
        }
    
    def printStats() = if (enable) {
        require(current.isEmpty)
        println("stats")
        for ((name, micros) <- scala.util.Sorting.stableSort(map.toList, (e: (String, Long)) => e._2))
            println(name + ": " + (micros / 1000))
    }
}

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