// from gee.cs.oswego.edu/home/jsr166/jsr166
package jsr166tests.loops;
/*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/licenses/publicdomain
*/
import java.util.*;
public class DenseMapMicroBenchmark {
static final int ITERS_PER_TEST = 4;
static final long NANOS_PER_JOB = 4L * 1000L*1000L*1000L; // 4 sec
static final long NANOS_PER_WARMUP = 500L*1000L*1000L; // 0.5 sec
// map operations per iteration -- change if hasher.work changed
static final int OPS_PER_ITER = 4; // put + get + iter + remove
static int SIZE = 50000; // may be replaced by program arg
abstract static class Job {
final String name;
long nanos;
int runs;
public Job(String name) { this.name = name; }
public String name() { return name; }
public abstract void work() throws Throwable;
}
/**
* Runs each job for at least NANOS_PER_JOB seconds.
* Returns array of average times per job per run.
*/
static void time0(long nanos, Job ... jobs) throws Throwable {
for (int i = 0; i < jobs.length; i++) {
Thread.sleep(50);
long t0 = System.nanoTime();
long t;
int j = 0;
do {
j++;
jobs[i].work();
} while ((t = System.nanoTime() - t0) < nanos);
jobs[i].nanos = t / j;
jobs[i].runs = j;
}
}
static void time(Job ... jobs) throws Throwable {
time0(NANOS_PER_JOB, jobs);
final String nameHeader = "Method";
int nameWidth = nameHeader.length();
for (Job job : jobs)
nameWidth = Math.max(nameWidth, job.name().length());
final int itemsPerTest = SIZE * OPS_PER_ITER * ITERS_PER_TEST;
final String timeHeader = "Nanos/item";
int timeWidth = timeHeader.length();
final String ratioHeader = "Ratio";
int ratioWidth = ratioHeader.length();
String format = String.format("%%-%ds %%%dd %%.3f%%n",
nameWidth, timeWidth);
String headerFormat = String.format("%%-%ds %%-%ds %%-%ds%%n",
nameWidth, timeWidth, ratioWidth);
System.out.printf(headerFormat, "Method", "Nanos/item", "Ratio");
// Print out absolute and relative times, calibrated against first job
for (int i = 0; i < jobs.length; i++) {
long time = jobs[i].nanos/itemsPerTest;
double ratio = (double) jobs[i].nanos / (double) jobs[0].nanos;
System.out.printf(format, jobs[i].name(), time, ratio);
}
}
static Long[] toLongs(Integer[] ints) {
Long[] longs = new Long[ints.length];
for (int i = 0; i < ints.length; i++)
longs[i] = ints[i].longValue();
return longs;
}
static String[] toStrings(Integer[] ints) {
String[] strings = new String[ints.length];
for (int i = 0; i < ints.length; i++)
strings[i] = ints[i].toString();
// strings[i] = String.valueOf(ints[i].doubleValue());
return strings;
}
static Float[] toFloats(Integer[] ints) {
Float[] floats = new Float[ints.length];
for (int i = 0; i < ints.length; i++)
floats[i] = ints[i].floatValue();
return floats;
}
static Double[] toDoubles(Integer[] ints) {
Double[] doubles = new Double[ints.length];
for (int i = 0; i < ints.length; i++)
doubles[i] = ints[i].doubleValue();
return doubles;
}
static final class Hasher extends Job {
final Object[] elts;
final Class mapClass;
volatile int matches;
Hasher(String name, Object[] elts, Class mapClass) {
super(name);
this.elts = elts;
this.mapClass = mapClass;
}
public void work() {
Map m = null;
try {
m = (Map) mapClass.newInstance();
} catch (Exception e) {
throw new RuntimeException("Can't instantiate " + mapClass + ": " + e);
}
final int len = elts.length;
for (int j = 0; j < ITERS_PER_TEST; j++) {
for (Object x : elts) {
if (m.put(x, x) != null)
throw new Error();
}
if (m.size() != len)
throw new Error();
int ng = 0;
for (Object x : elts) {
if (m.get(x) == x)
++ng;
}
matches += ng;
for (Object e : m.keySet()) {
if (m.get(e) == e)
--ng;
}
if (ng != 0)
throw new Error();
for (Object x : elts) {
if (m.remove(x) != x)
throw new Error();
}
if (!m.isEmpty())
throw new Error();
}
if (matches != len * ITERS_PER_TEST)
throw new Error();
matches = 0;
}
}
public static void main(String[] args) throws Throwable {
Class mc = java.util.HashMap.class;
if (args.length > 0)
mc = Class.forName(args[0]);
if (args.length > 1)
SIZE = Integer.parseInt(args[1]);
System.out.print("Class " + mc.getName());
System.out.print(" size " + SIZE);
System.out.println();
final Integer[] seq = new Integer[SIZE];
for (int i = 0; i < SIZE; i++)
seq[i] = new Integer(i);
final Integer[] shf = seq.clone();
Collections.shuffle(Arrays.asList(shf));
List<Hasher> hashers = new ArrayList<Hasher>();
hashers.add(new Hasher("Integer sequential", seq, mc));
hashers.add(new Hasher("Integer shuffled", shf, mc));
hashers.add(new Hasher("Long sequential", toLongs(seq), mc));
hashers.add(new Hasher("Long shuffled", toLongs(shf), mc));
hashers.add(new Hasher("Float sequential", toFloats(seq), mc));
hashers.add(new Hasher("Float shuffled", toFloats(shf), mc));
hashers.add(new Hasher("Double sequential", toDoubles(seq), mc));
hashers.add(new Hasher("Double shuffled", toDoubles(shf), mc));
hashers.add(new Hasher("String sequential", toStrings(seq), mc));
hashers.add(new Hasher("String shuffled", toStrings(shf), mc));
Hasher[] jobs = hashers.toArray(new Hasher[0]);
System.out.print("warmup...");
time0(NANOS_PER_WARMUP, jobs); // Warm up run
time0(NANOS_PER_WARMUP, jobs); // Warm up run
for (int i = 0; i < 2; i++) {
System.gc();
Thread.sleep(50);
System.runFinalization();
Thread.sleep(50);
}
System.out.println("starting");
time(jobs);
}
}