Improve performance test framework by adding time and size factors

modules/core/src/test/java/test/jts/perf/PerformanceTestCase.java

@@ -16,14 +16,26 @@
  * A base class for classes implementing performance tests
  * to be run by the {@link PerformanceTestRunner}.
  * <p>
- * In a subclass of this class,
- * all public methods which start with <code>run</code> are 
- * executed as performance tests.
+ * The {@link #setUp()} is called at the start of test class execution, 
+ * and {@link #tearDown()} is called at the end.  
+ * These allow creating and release resources needed for testing
+ * (e.g. a database connection).
  * <p>
- * Multiple test runs with different run sizes may be made.
- * Within each run, each <code>run</code> method is executed 
- * the specified number of iterations.
- * The time to run the method is printed for each one.
+ * Subclasses provide performance tests as
+ * public methods which start with <code>run</code>.
+ * Each test is executed once per test run.
+ * The number of runs is determined by the length
+ * of the array provided to {@link #setRunSize(int[])}.  
+ * The array entry for each run specifies a size for the run.
+ * The size is provided at the start of each run via {@link #startRun(int)}.
+ * It can be used to determine the size of data to generate for the run.
+ * <p>
+ * Within a run, each <code>run</code> test method is executed 
+ * for the number of iterations specified by {@link #setRunIterations(int).
+ * This allows running tests of fast operations long enough for accurate timing.
+ * A performance report is printed after each test.
+ * <p>
+ * {@link #endRun()} is called at the end of the run.
  * 
  * @author Martin Davis
  *
@@ -40,14 +52,19 @@ public PerformanceTestCase(String name)
     this.name = name;
   }
 
+  /**
+   * Gets the name of this test case.
+   * 
+   * @return the name of the test case
+   */
   public String getName()
   {
     return name;
   }
 
   /**
-   * Sets the size(s) for the runs of the test.
-   * The default is 1 iteration.
+   * Sets the size(s) for the runs of the test(s).
+   * The default is one run with a size of 1.
    * 
    * @param runSize a list of the sizes for the test runs
    */
@@ -57,18 +74,31 @@ protected void setRunSize(int[] runSize)
     runTime = new long[runSize.length];
   }
 
+  /**
+   * Gets the array of run sizes.
+   * 
+   * @return the array of run sizes
+   */
   public int[] getRunSize()
   {
     return runSize;
   }
 
+  /**
+   * Gets the run times for the final run method in each run.
+   * This allows comparing run times across different run sizes
+   * (e.g. to compute a time factor).
+   * 
+   * @return the run times
+   */
   public long[] getRunTime()
   {
     return runTime;
   }
 
   /**
    * Sets the number of iterations to execute the test methods in each test run.
+   * The default is 1 iteration.
    * 
    * @param runIter the number of iterations to execute.
    */
@@ -77,6 +107,11 @@ protected void setRunIterations(int runIter)
     this.runIter = runIter;
   }
 
+  /**
+   * Gets the number of iterations for the run methods.
+   * 
+   * @return the number of iterations
+   */
   public int getRunIterations()
   {
     return runIter;

modules/core/src/test/java/test/jts/perf/PerformanceTestRunner.java

@@ -33,8 +33,6 @@ public class PerformanceTestRunner
 {
   private static final String RUN_PREFIX = "run";
 
-  private static final String INIT_METHOD = "init";
-
   public static void run(Class clz)
   {
     PerformanceTestRunner runner = new PerformanceTestRunner();
@@ -57,6 +55,9 @@ private void runInternal(Class clz)
 
       // do the run
       test.setUp();
+      //-- initial times are zero (factor is not printed)
+      long[] runTimePrev = new long[runMethod.length];
+
       for (int runNum = 0; runNum < runSize.length; runNum++)
       {
         int size = runSize[runNum];
@@ -67,8 +68,10 @@ private void runInternal(Class clz)
             runMethod[i].invoke(test);
           }
           long time = sw.getTime();
-          System.out.println(runMethod[i].getName()
-              + " : " + sw.getTimeString());
+          long timePrev = runTimePrev[i];
+          int sizePrev = runNum > 0 ? runSize[runNum-1] : -1;
+          reportRun(runMethod[i].getName(), sw.getTimeString(), size, time, sizePrev, timePrev);
+          runTimePrev[i] = time;
           test.setTime(runNum, time);
         }
         test.endRun();
@@ -84,6 +87,17 @@ private void runInternal(Class clz)
   }
 
 
+  private void reportRun(String name, String timeString, int size, long time, int sizePrev, long timePrev) {
+    String factorStr = "";
+    if (sizePrev > 0 && timePrev > 0) {
+      double sizeFactor = size / (double) sizePrev;
+      double timeFactor = time / (double) timePrev;
+      factorStr = String.format( "  ( %.1fx - size %.1fx)", timeFactor, sizeFactor);
+    }
+    System.out.println(name
+        + " : " + timeString + factorStr);
+  }
+
   private static Method[] findMethods(Class clz, String methodPrefix)
   {
     List runMeths = new ArrayList();