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    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
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   * specific language governing permissions and limitations
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   *
   * This software consists of voluntary contributions made by many
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  package org.apache.hc.client5.http.impl.classic;
  
  
  import org.apache.hc.client5.http.HttpRoute;
  import org.apache.hc.core5.http.HttpHost;
  import org.apache.hc.core5.util.TimeValue;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  public class TestLinearBackoffManager {
  
      private LinearBackoffManager impl;
      private MockConnPoolControl connPerRoute;
      private HttpRoute route;
      private static final long DEFAULT_COOL_DOWN_MS = 10;
  
      @BeforeEach
      public void setUp() {
          connPerRoute = new MockConnPoolControl();
          route = new HttpRoute(new HttpHost("localhost", 80));
          impl = new LinearBackoffManager(connPerRoute);
          impl.setCoolDown(TimeValue.ofMilliseconds(DEFAULT_COOL_DOWN_MS));
      }
  
      @Test
      public void incrementsConnectionsOnBackoff() {
          final LinearBackoffManager impl = new LinearBackoffManager(connPerRoute);
          impl.setCoolDown(TimeValue.ofMilliseconds(DEFAULT_COOL_DOWN_MS)); // Set the cool-down period
          connPerRoute.setMaxPerRoute(route, 4);
          impl.backOff(route);
          assertEquals(5, connPerRoute.getMaxPerRoute(route));
      }
  
      @Test
      public void decrementsConnectionsOnProbe() {
          connPerRoute.setMaxPerRoute(route, 4);
          impl.probe(route);
          assertEquals(3, connPerRoute.getMaxPerRoute(route));
      }
  
      @Test
      public void backoffDoesNotAdjustDuringCoolDownPeriod() {
          connPerRoute.setMaxPerRoute(route, 4);
          impl.backOff(route);
          final long max = connPerRoute.getMaxPerRoute(route);
          // Replace Thread.sleep(1) with busy waiting
          final long end = System.currentTimeMillis() + 1;
          while (System.currentTimeMillis() < end) {
              // Busy waiting
          }
  
          impl.backOff(route);
          assertEquals(max, connPerRoute.getMaxPerRoute(route));
      }
  
      @Test
      public void backoffStillAdjustsAfterCoolDownPeriod() throws InterruptedException {
          final LinearBackoffManager impl = new LinearBackoffManager(connPerRoute);
          impl.setCoolDown(TimeValue.ofMilliseconds(DEFAULT_COOL_DOWN_MS)); // Set the cool-down period
          connPerRoute.setMaxPerRoute(route, 4);
          impl.backOff(route);
          final int max1 = connPerRoute.getMaxPerRoute(route);
  
          Thread.sleep(DEFAULT_COOL_DOWN_MS + 1); // Sleep for cooldown period + 1 ms
  
          impl.backOff(route);
          final int max2 = connPerRoute.getMaxPerRoute(route);
  
          assertTrue(max2 > max1);
      }
 
 
     @Test
     public void probeDoesNotAdjustDuringCooldownPeriod() {
         connPerRoute.setMaxPerRoute(route, 4);
         impl.probe(route);
         final long max = connPerRoute.getMaxPerRoute(route);
         // Replace Thread.sleep(1) with busy waiting
         final long end = System.currentTimeMillis() + 1;
         while (System.currentTimeMillis() < end) {
             // Busy waiting
         }
 
         impl.probe(route);
         assertEquals(max, connPerRoute.getMaxPerRoute(route));
     }
 
     @Test
     public void probeStillAdjustsAfterCoolDownPeriod() throws InterruptedException {
         connPerRoute.setMaxPerRoute(route, 4);
         impl.probe(route);
         Thread.sleep(DEFAULT_COOL_DOWN_MS + 1); // Sleep for cooldown period + 1 ms
         impl.probe(route);
         final long newMax = connPerRoute.getMaxPerRoute(route);
         assertEquals(2, newMax); // The cap is set to 2 by default
     }
 
     @Test
     public void testSetPerHostConnectionCap() {
         connPerRoute.setMaxPerRoute(route, 5);
         impl.setPerHostConnectionCap(10); // Set the cap to a higher value
         impl.backOff(route);
         assertEquals(6, connPerRoute.getMaxPerRoute(route));
     }
 
     @Test
     public void probeUpdatesRemainingAttemptsIndirectly() throws InterruptedException {
         // Set initial max per route
         connPerRoute.setMaxPerRoute(route, 4);
 
         // Apply backOff twice
         impl.backOff(route);
         Thread.sleep(DEFAULT_COOL_DOWN_MS + 1);
         impl.backOff(route);
 
         // Ensure that connection pool size has increased
         assertEquals(6, connPerRoute.getMaxPerRoute(route));
 
         // Apply probe once
         impl.probe(route);
 
         // Wait for a longer cool down period
         Thread.sleep(DEFAULT_COOL_DOWN_MS * 2);
 
         // Apply probe once more
         impl.probe(route);
 
         // Check that connection pool size has decreased once, indicating that the remaining attempts were updated
         assertEquals(5, connPerRoute.getMaxPerRoute(route));
     }
 
     @Test
     public void linearIncrementTest() throws InterruptedException {
         final int initialMax = 4;
         connPerRoute.setMaxPerRoute(route, initialMax);
         for (int i = 1; i <= 5; i++) {
             impl.backOff(route);
             assertEquals(initialMax + i, connPerRoute.getMaxPerRoute(route));
             Thread.sleep(DEFAULT_COOL_DOWN_MS + 1);
 
         }
     }
 }