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.distributedlog.common.config;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertTrue;
  
  import java.io.File;
  import java.util.Collections;
  import java.util.List;
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.concurrent.atomic.AtomicReference;
  import org.apache.commons.configuration2.CompositeConfiguration;
  import org.apache.commons.configuration2.event.ConfigurationEvent;
  import org.jmock.lib.concurrent.DeterministicScheduler;
  import org.junit.Test;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Notes:
   * 1. lastModified granularity is platform dependent, generally 1 sec, so we can't wait 1ms for things to
   * get picked up.
   */
  public class TestConfigurationSubscription {
      static final Logger LOG = LoggerFactory.getLogger(TestConfigurationSubscription.class);
      public static final int RELOAD_PERIOD = 10;
  
      /**
       * Give some time to handle reloading.
       */
      private void ensureConfigReloaded() throws InterruptedException {
          Thread.sleep(1);
      }
  
      @Test(timeout = 60000)
      public void testReloadConfiguration() throws Exception {
          PropertiesWriter writer = new PropertiesWriter();
          ConcurrentConstConfiguration conf = new ConcurrentConstConfiguration(new CompositeConfiguration());
          DeterministicScheduler executorService = new DeterministicScheduler();
          List<File> configFiles = Collections.singletonList(writer.getFile());
          ConfigurationSubscription confSub =
                  new ConfigurationSubscription(conf, configFiles, executorService, RELOAD_PERIOD, TimeUnit.MILLISECONDS);
          final AtomicReference<ConcurrentBaseConfiguration> confHolder = new AtomicReference<>();
          confSub.registerListener(new org.apache.distributedlog.common.config.ConfigurationListener() {
              @Override
              public void onReload(ConcurrentBaseConfiguration conf) {
                  confHolder.set(conf);
              }
          });
          assertEquals(null, conf.getProperty("prop1"));
  
          // add
          writer.setProperty("prop1", "1");
          writer.save();
          // ensure the file change reloading event can be triggered
          ensureConfigReloaded();
          executorService.tick(RELOAD_PERIOD, TimeUnit.MILLISECONDS);
          assertNotNull(confHolder.get());
          assertTrue(conf == confHolder.get());
          assertEquals("1", conf.getProperty("prop1"));
      }
  
      @Test(timeout = 60000)
      public void testAddReloadBasicsConfig() throws Exception {
          PropertiesWriter writer = new PropertiesWriter();
          DeterministicScheduler mockScheduler = new DeterministicScheduler();
          ConcurrentConstConfiguration conf = new ConcurrentConstConfiguration(new CompositeConfiguration());
          List<File> configFiles = Collections.singletonList(writer.getFile());
          ConfigurationSubscription confSub =
                  new ConfigurationSubscription(conf, configFiles, mockScheduler, RELOAD_PERIOD, TimeUnit.MILLISECONDS);
          assertEquals(null, conf.getProperty("prop1"));
  
          // add
          writer.setProperty("prop1", "1");
          writer.save();
          // ensure the file change reloading event can be triggered
          ensureConfigReloaded();
          mockScheduler.tick(RELOAD_PERIOD, TimeUnit.MILLISECONDS);
          assertEquals("1", conf.getProperty("prop1"));
  
      }
  
      @Test(timeout = 60000)
      public void testInitialConfigLoad() throws Exception {
          PropertiesWriter writer = new PropertiesWriter();
          writer.setProperty("prop1", "1");
          writer.setProperty("prop2", "abc");
          writer.setProperty("prop3", "123.0");
          writer.setProperty("prop4", "11132");
          writer.setProperty("prop5", "true");
          writer.save();
  
          ScheduledExecutorService mockScheduler = new DeterministicScheduler();
          ConcurrentConstConfiguration conf = new ConcurrentConstConfiguration(new CompositeConfiguration());
          List<File> configFiles = Collections.singletonList(writer.getFile());
          ConfigurationSubscription confSub =
                  new ConfigurationSubscription(conf, configFiles, mockScheduler, RELOAD_PERIOD, TimeUnit.MILLISECONDS);
          assertEquals(1, conf.getInt("prop1"));
          assertEquals("abc", conf.getString("prop2"));
          assertEquals(123.0, conf.getFloat("prop3"), 0);
          assertEquals(11132, conf.getInt("prop4"));
          assertEquals(true, conf.getBoolean("prop5"));
      }
  
      @Test(timeout = 60000)
      public void testExceptionInConfigLoad() throws Exception {
          PropertiesWriter writer = new PropertiesWriter();
          writer.setProperty("prop1", "1");
          writer.save();
  
          DeterministicScheduler mockScheduler = new DeterministicScheduler();
          ConcurrentConstConfiguration conf = new ConcurrentConstConfiguration(new CompositeConfiguration());
          List<File> configFiles = Collections.singletonList(writer.getFile());
          ConfigurationSubscription confSub =
                  new ConfigurationSubscription(conf, configFiles, mockScheduler, RELOAD_PERIOD, TimeUnit.MILLISECONDS);
  
          final AtomicInteger count = new AtomicInteger(1);
          conf.addEventListener(ConfigurationEvent.ANY, event -> {
                  LOG.info("config changed {}", event);
                  // Throw after so we actually see the update anyway.
                  if (!event.isBeforeUpdate()) {
                      count.getAndIncrement();
                      throw new RuntimeException("config listener threw and exception");
                  }
              });
  
          int i = 0;
          int initial = 0;
          while (count.get() == initial) {
              writer.setProperty("prop1", Integer.toString(i++));
              writer.save();
              ensureConfigReloaded();
              mockScheduler.tick(RELOAD_PERIOD, TimeUnit.MILLISECONDS);
          }
  
          initial = count.get();
          while (count.get() == initial) {
              writer.setProperty("prop1", Integer.toString(i++));
              writer.save();
              ensureConfigReloaded();
              mockScheduler.tick(RELOAD_PERIOD, TimeUnit.MILLISECONDS);
          }
      }
  }
  