Scala benchmark suite added

1 files changed, 74 insertions, 0 deletions

diff --git a/sources/scala/testing/Benchmark.scala b/sources/scala/testing/Benchmark.scala
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+++ b/sources/scala/testing/Benchmark.scala
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+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003-2004, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |                                         **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+** $Id$
+\*                                                                      */
+
+
+/**
+ * Scala benchmarking mini framework.
+ */
+
+package scala.testing;
+
+/** <code>Benchmark</code> can be used to quickly turn an existing
+ *  class into a benchmark. Here is a short example:
+ *
+ *  <pre>
+ *  object sort1 extends Sorter with Benchmark {
+ *     def run = sort(List.range(1, 1000));
+ *  }
+ *  </pre>
+ *
+ * The run method has to be defined by the user, who will perform
+ * the timed operation there.
+ * Run the benchmark as follows:
+ * <pre>
+ *   scala sort1 5 times.log
+ * </pre>
+ * This will run the benchmark 5 times and log the execution times in
+ * a file called times.log
+ */
+trait Benchmark {
+
+  /** this method should be implemented by the concrete benchmark */
+  def run: Unit;
+
+  /** Run the benchmark the specified number of times
+   *  and return a list with the execution times in milliseconds
+   *  in reverse order of the execution */
+  def runBenchmark(noTimes: Int): List[Long] =
+
+    for (val i <- List.range(1, noTimes + 1)) yield {
+      val startTime = System.currentTimeMillis();
+      run;
+      val stopTime = System.currentTimeMillis();
+      System.gc();
+
+      stopTime - startTime
+    }
+
+  /**
+  * The entry point. It takes two arguments: the number of
+  * consecutive runs, and the name of a log file where to
+  * append the times.
+  *
+  */
+  def main(args: Array[String]): Unit = {
+    if (args.length > 1) {
+      val logFile = new java.io.FileWriter(args(1), true); // append, not overwrite
+
+      logFile.write(getClass().getName());
+      for (val t <- runBenchmark(Integer.parseInt(args(0))))
+	logFile.write("\t\t" + t);
+
+      logFile.write("\n");
+      logFile.flush();
+    } else
+      Console.println("Usage: scala benchmarks.program <runs> <logfile>");
+  }
+}
+