content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.kafka.common.utils;
  
  import org.junit.jupiter.api.Test;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  public class ExponentialBackoffTest {
      @Test
      public void testExponentialBackoff() {
          long scaleFactor = 100;
          int ratio = 2;
          long backoffMax = 2000;
          double jitter = 0.2;
          ExponentialBackoff exponentialBackoff = new ExponentialBackoff(
                  scaleFactor, ratio, backoffMax, jitter
          );
  
          for (int i = 0; i <= 100; i++) {
              for (int attempts = 0; attempts <= 10; attempts++) {
                  if (attempts <= 4) {
                      assertEquals(scaleFactor * Math.pow(ratio, attempts),
                              exponentialBackoff.backoff(attempts),
                              scaleFactor * Math.pow(ratio, attempts) * jitter);
                  } else {
                      assertTrue(exponentialBackoff.backoff(attempts) <= backoffMax * (1 + jitter));
                  }
              }
          }
      }
  
      @Test
      public void testExponentialBackoffWithoutJitter() {
          ExponentialBackoff exponentialBackoff = new ExponentialBackoff(100, 2, 400, 0.0);
          assertEquals(100, exponentialBackoff.backoff(0));
          assertEquals(200, exponentialBackoff.backoff(1));
          assertEquals(400, exponentialBackoff.backoff(2));
          assertEquals(400, exponentialBackoff.backoff(3));
      }
  }
  