import io.aeron.Aeron;
import io.aeron.Publication;
import io.aeron.driver.MediaDriver;
import org.agrona.concurrent.UnsafeBuffer;

import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;

public class Publisher {
  public static void main(String[] args) throws Exception {
    MediaDriver driver = MediaDriver.launchEmbedded();

    Aeron.Context ctx = new Aeron.Context()
        .aeronDirectoryName(driver.aeronDirectoryName());

    Aeron aeron = Aeron.connect(ctx);

    String channel = "aeron:udp?endpoint=subscriber:40123";
    int streamId = 1001;

    Publication publication = aeron.addPublication(channel, streamId);
    UnsafeBuffer buffer = new UnsafeBuffer(ByteBuffer.allocateDirect(256));

    long counter = 0;

    System.out.println("Publisher ready");

    while (true) {
      long timestamp = System.currentTimeMillis();
      String msg = counter + "," + timestamp;

      buffer.setMemory(0, buffer.capacity(), (byte) 0);

      byte[] bytes = msg.getBytes(StandardCharsets.UTF_8);
      buffer.putBytes(0, bytes);

      long result;
      do {
        result = publication.offer(buffer, 0, bytes.length);
        if (result < 0)
          Thread.yield();
      } while (result < 0);

      System.out.println("Sent: " + msg);
      counter++;
      Thread.sleep(1000);
    }
  }
}