import java.net.URI;
import java.net.http.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;

/** Fires TOTAL requests with THREADS threads and reports how long each batch of BATCH took. */
public class Warmup {
    public static void main(String[] a) throws Exception {
        int port = Integer.parseInt(a[0]);
        int total = 20_000, batch = 2_000, threads = 4;
        HttpClient c = HttpClient.newBuilder().version(HttpClient.Version.HTTP_1_1).build();
        HttpRequest rq = HttpRequest.newBuilder(URI.create("http://localhost:" + port + "/hello")).build();
        AtomicInteger done = new AtomicInteger();
        long[] batchEnd = new long[total / batch];
        long t0 = System.nanoTime();
        ExecutorService ex = Executors.newFixedThreadPool(threads);
        List<Future<?>> fs = new ArrayList<>();
        for (int t = 0; t < threads; t++) fs.add(ex.submit(() -> {
            try {
                while (true) {
                    int n = done.incrementAndGet();
                    if (n > total) return null;
                    c.send(rq, HttpResponse.BodyHandlers.discarding());
                    if (n % batch == 0) batchEnd[n / batch - 1] = System.nanoTime();
                }
            } catch (Exception e) { throw new RuntimeException(e); }
        }));
        for (Future<?> f : fs) f.get();
        ex.shutdown();
        StringBuilder sb = new StringBuilder("batch ms:");
        long prev = t0;
        for (long e : batchEnd) { sb.append(' ').append((e - prev) / 1_000_000); prev = e; }
        System.out.println(sb);
        System.out.println("total ms: " + (prev - t0) / 1_000_000);
    }
}