ICU-2038 add performance test class

X-SVN-Rev: 9897

icu4j/src/com/ibm/icu/dev/test/PerfTest.java

@@ -0,0 +1,73 @@
+/*
+**********************************************************************
+* Copyright (c) 2002, International Business Machines
+* Corporation and others.  All Rights Reserved.
+**********************************************************************
+* $Source: /xsrl/Nsvn/icu/icu4j/src/com/ibm/icu/dev/test/Attic/PerfTest.java,v $ 
+* $Date: 2002/09/19 23:00:52 $ 
+* $Revision: 1.1 $
+**********************************************************************
+*/
+
+package com.ibm.icu.dev.test;
+import com.ibm.icu.text.NumberFormat;
+
+/**
+ * A class for doing performance testing.  To use, subclass and
+ * implement the test() method.
+ */
+public abstract class PerfTest {
+
+    /**
+     * Subclasses must implement this method to do the action to
+     * be measured.
+     * @return the number of iterations run by this method, >= 1.
+     */
+    protected abstract int test();
+
+    /**
+     * Measure the time required by the test() method.
+     * @param iterations number of times to call test().  Must be >= 1.
+     * @return the time per iteration in seconds.  Iterations, in this
+     * case, are counted as 'iterations' * the result of test() or
+     * empty().
+     */
+    public double measure(int iterations, TestLog log) {
+        if (iterations < 0) {
+            throw new IllegalArgumentException("Invalid iterations");
+        }
+
+        int i, count;
+
+        double start, stop, limit;
+
+        // Call test() first
+        count = 0;
+        start = System.currentTimeMillis();
+        for (i=0; i<iterations; ++i) {
+            count += test();
+        }
+        stop = System.currentTimeMillis();
+        
+        double result = (stop - start) / count;
+
+        if (log != null) {
+            log.logln("test() elapsed " + (stop - start) +
+                      " ms, count " + count +
+                      ", " + nf.format(1000*result) + " us/count");
+        }
+
+        return result / 1000; // ms => s
+    }
+
+    /**
+     * Convenience.
+     */
+    public final double measure(int iterations) {
+        return measure(iterations, null);
+    }
+
+    static NumberFormat nf = NumberFormat.getInstance();
+}
+
+//eof