content: package io.jafka;
  
  import org.junit.Ignore;
  
  import java.util.concurrent.Callable;
  import java.util.concurrent.TimeUnit;
  
  @Ignore
  public class TestUtil {
  
      static {
          System.setProperty("zookeeper.preAllocSize", "1024");//1M data log
      }
      /**
       * This waits until the provided {@link Callable} returns an object that is equals to the given expected value or
       * the timeout has been reached. In both cases this method will return the return value of the latest
       * {@link Callable} execution.
       * 
       * @param expectedValue
       *            The expected value of the callable.
       * @param callable
       *            The callable.
       * @param <T>
       *            The return type of the callable.
       * @param timeUnit
       *            The timeout timeunit.
       * @param timeout
       *            The timeout.
       * @return the return value of the latest {@link Callable} execution.
       * @throws Exception
       * @throws InterruptedException
       */
      public static <T> T waitUntil(T expectedValue, Callable<T> callable, TimeUnit timeUnit, long timeout) throws Exception {
          long startTime = System.currentTimeMillis();
          do {
              T actual = callable.call();
              if (expectedValue.equals(actual)) {
                  return actual;
              }
              if (System.currentTimeMillis() > startTime + timeUnit.toMillis(timeout)) {
                  return actual;
              }
              Thread.sleep(50);
          } while (true);
      }
  
  }