Tiny benchmark class

B.java

/** A tiny benchmark class */
public static class B {

	private int count = 0;
	private long start;
	private long end;
	private long min = Long.MAX_VALUE;
	private long max;
	private String label;

	public B(String label) {
		this.label = label;
	}

	public boolean done() {
		long t = System.nanoTime();
		if (this.count == 0) {
			this.start = this.end = t;
		} else {
			long d = t - this.end;
			if (d < this.min) {
				this.min = d;
			}
			if (d > this.max) {
				this.max = d;
			}
		}
		this.end = t;
		this.count++;
		return this.end - this.start >= 5*1e9 || count >= 1000000;
	}

	public String report() {
		return "Benchmark " + this.label + "\t\t" + this.ops() + "\t" + (this.op() / 1000000) +
			"ms/op, min=" + (this.min/1000000) + ", max=" + (this.max/1000000);
	}

	public int ops() {
		return this.count - 1;
	}

	public double op() {
		return this.time()/this.ops();
	}

	public long time() {
		return (this.end - this.start);
	}
}

Usage:

B b = new B("My benchmark");
while (!b.done()) {
...
}
System.out.println(b.report());