code: /*
   * 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.skywalking.oap.server.core.analysis;
  
  import com.google.common.base.Strings;
  import java.io.FileNotFoundException;
  import java.io.Reader;
  import java.io.StringReader;
  import java.util.Collections;
  import java.util.Map;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.oap.server.configuration.api.ConfigChangeWatcher;
  import org.apache.skywalking.oap.server.core.CoreModule;
  import org.apache.skywalking.oap.server.core.CoreModuleProvider;
  import org.apache.skywalking.oap.server.library.util.ResourceUtils;
  import org.yaml.snakeyaml.LoaderOptions;
  import org.yaml.snakeyaml.Yaml;
  import org.yaml.snakeyaml.constructor.SafeConstructor;
  
  /**
   * Apdex threshold configuration dictionary adapter. Looking up a service apdex threshold from dynamic config service.
   */
  @Slf4j
  public class ApdexThresholdConfig extends ConfigChangeWatcher implements ConfigurationDictionary {
  
      private static final String CONFIG_FILE_NAME = "service-apdex-threshold.yml";
  
      private static final int SYSTEM_RESERVED_THRESHOLD = 500;
  
      private Map<String, Integer> dictionary = Collections.emptyMap();
  
      private String rawConfig = null;
  
      public ApdexThresholdConfig(final CoreModuleProvider provider) {
          super(CoreModule.NAME, provider, "apdexThreshold");
          try {
              updateConfig(ResourceUtils.read(CONFIG_FILE_NAME));
          } catch (final FileNotFoundException e) {
              log.error("Cannot config from: {}", CONFIG_FILE_NAME, e);
          }
      }
  
      @Override
      public Number lookup(String name) {
          int t = dictionary.getOrDefault(name, -1);
          if (t < 0) {
              t = dictionary.getOrDefault("default", -1);
          }
          if (t < 0) {
              log.warn("Pick up system reserved threshold {}ms because of config missing", SYSTEM_RESERVED_THRESHOLD);
              return SYSTEM_RESERVED_THRESHOLD;
          }
          if (log.isDebugEnabled()) {
              log.debug("Apdex threshold of {} is {}ms", name, t);
          }
          return t;
      }
  
      @Override
      public void notify(ConfigChangeEvent value) {
          if (EventType.DELETE.equals(value.getEventType())) {
              activeSetting(null);
          } else {
              activeSetting(value.getNewValue());
          }
      }
  
      @Override
      public String value() {
          return rawConfig;
      }
  
      private synchronized void activeSetting(String config) {
          if (log.isDebugEnabled()) {
              log.debug("Updating using new static config: {}", config);
          }
          rawConfig = config;
          updateConfig(new StringReader(Strings.nullToEmpty(config)));
      }
  
      @SuppressWarnings("unchecked")
      private void updateConfig(final Reader contentRender) {
          dictionary = new Yaml(new SafeConstructor(new LoaderOptions())).load(contentRender);
          if (dictionary == null) {
              dictionary = Collections.emptyMap();
          }
      }
  }
  