neopragma / java-test-timer

Measure elapsed time in nanoseconds between two points in an execution path.

Java Test Timer

Measures elapsed time between two points in an execution path.

Usage with JUnit4

private Timer timer;

@BeforeClass
public void beforeAll() {
    timer = new Timer();
}

@AfterClass
public static void afterAll() {
  timer.dumpTimings();
}

@Test
public void junitTestMethod() {
    timer.startTimer();
    // test method body
    timer.stopTimer();
}

See the test cases in the project for more usage examples.

The dumpTimings() method writes the collected timings to the PrintStream specified on the Timer constructor Timer(PrintStream ps) or, by default, to System.out. It produces output that looks like this:

------------------------------------------------------------
Timings for java8.sandbox.functions.FunctionsTest

addition_inline_Integers.........................................         608,900 ns
differenceOfSquares_class........................................         585,781 ns
differenceOfSquares_inline.......................................         282,575 ns
differenceOfSquares_utility......................................         523,390 ns
exponentiation...................................................         616,010 ns
increment_class_Integer..........................................         559,687 ns
increment_inline_Integer.........................................         418,412 ns
increment_utility_Integer........................................       1,038,834 ns

------------------------------------------------------------
Timings for java8.sandbox.predicate.CatalogSearchTest

itFindsEntriesByManufacturer_preJava8............................         479,167 ns
itFindsEntriesByManufacturer_usingPredicate......................         385,123 ns
itFindsEntriesByManufacturer_usingStreamsAndFilter...............         752,981 ns
itFindsEntriesByTextInDescription_preJava8.......................         404,558 ns
itFindsEntriesByTextInDescription_usingPredicate.................         955,732 ns
itFindsEntriesByTextInDescription_usingStreamsAndFilter..........      19,235,177 ns
itSortsResultsByProductName_preJava8.............................         640,303 ns
itSortsResultsByProductName_usingLambda..........................       3,517,193 ns
itSortsResultsByProductName_usingStreams.........................       3,141,018 ns
itSortsResultsByProductName_usingStreamsAndAnonymousInnerClass...         781,979 ns