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.worker;
  
  import lombok.Getter;
  import lombok.Setter;
  import org.apache.skywalking.oap.server.core.CoreModule;
  import org.apache.skywalking.oap.server.core.UnexpectedException;
  import org.apache.skywalking.oap.server.core.analysis.DownSampling;
  import org.apache.skywalking.oap.server.core.analysis.MetricsExtension;
  import org.apache.skywalking.oap.server.core.analysis.Stream;
  import org.apache.skywalking.oap.server.core.analysis.StreamDefinition;
  import org.apache.skywalking.oap.server.core.analysis.StreamProcessor;
  import org.apache.skywalking.oap.server.core.analysis.metrics.Metrics;
  import org.apache.skywalking.oap.server.core.config.DownSamplingConfigService;
  import org.apache.skywalking.oap.server.core.storage.IMetricsDAO;
  import org.apache.skywalking.oap.server.core.storage.StorageBuilderFactory;
  import org.apache.skywalking.oap.server.core.storage.StorageDAO;
  import org.apache.skywalking.oap.server.core.storage.StorageException;
  import org.apache.skywalking.oap.server.core.storage.StorageModule;
  import org.apache.skywalking.oap.server.core.storage.annotation.Storage;
  import org.apache.skywalking.oap.server.core.storage.model.Model;
  import org.apache.skywalking.oap.server.core.storage.model.ModelCreator;
  import org.apache.skywalking.oap.server.core.storage.type.StorageBuilder;
  import org.apache.skywalking.oap.server.core.worker.IWorkerInstanceSetter;
  import org.apache.skywalking.oap.server.library.module.ModuleDefineHolder;
  
  import java.lang.reflect.InvocationTargetException;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  /**
   * MetricsStreamProcessor represents the entrance and creator of the metrics streaming aggregation work flow.
   *
   * {@link #in(Metrics)} provides the major entrance for metrics streaming calculation.
   *
   * {@link #create(ModuleDefineHolder, Stream, Class)} creates the workers and work flow for every metrics.
   */
  public class MetricsStreamProcessor implements StreamProcessor<Metrics> {
      /**
       * Singleton instance.
       */
      private final static MetricsStreamProcessor PROCESSOR = new MetricsStreamProcessor();
  
      /**
       * Worker table hosts all entrance workers.
       */
      private Map<Class<? extends Metrics>, MetricsAggregateWorker> entryWorkers = new HashMap<>();
  
      /**
       * Worker table hosts all persistent workers.
       */
      @Getter
      private List<MetricsPersistentWorker> persistentWorkers = new ArrayList<>();
  
      /**
       * The period of L1 aggregation flush. Unit is ms.
       */
      @Setter
      @Getter
      private long l1FlushPeriod = 500;
      /**
       * The threshold of session time. Unit is ms. Default value is 70s.
       */
      @Setter
      private long storageSessionTimeout = 70_000;
      /**
       * @since 8.7.0 TTL settings from {@link org.apache.skywalking.oap.server.core.CoreModuleConfig#getMetricsDataTTL()}
       */
      @Setter
      private int metricsDataTTL = 3;
  
      public static MetricsStreamProcessor getInstance() {
          return PROCESSOR;
      }
  
      @Override
      public void in(Metrics metrics) {
          MetricsAggregateWorker worker = entryWorkers.get(metrics.getClass());
          if (worker != null) {
              worker.in(metrics);
          }
      }
  
      /**
       * Create the workers and work flow for OAL metrics.
       *
       * @param moduleDefineHolder pointer of the module define.
       * @param stream             definition of the metrics class.
       * @param metricsClass       data type of the streaming calculation.
       */
      public void create(ModuleDefineHolder moduleDefineHolder,
                         Stream stream,
                         Class<? extends Metrics> metricsClass) throws StorageException {
          this.create(moduleDefineHolder, StreamDefinition.from(stream), metricsClass, MetricStreamKind.OAL);
      }
  
      /**
       * Create the workers and work flow for MAL meter
       */
      public void create(ModuleDefineHolder moduleDefineHolder,
                         StreamDefinition stream,
                         Class<? extends Metrics> meterClass) throws StorageException {
          this.create(moduleDefineHolder, stream, meterClass, MetricStreamKind.MAL);
      }
  
      private void create(ModuleDefineHolder moduleDefineHolder,
                          StreamDefinition stream,
                          Class<? extends Metrics> metricsClass,
                          MetricStreamKind kind) throws StorageException {
          final StorageBuilderFactory storageBuilderFactory = moduleDefineHolder.find(StorageModule.NAME)
                                                                                .provider()
                                                                                .getService(StorageBuilderFactory.class);
          final Class<? extends StorageBuilder> builder = storageBuilderFactory.builderOf(
              metricsClass, stream.getBuilder());
  
          StorageDAO storageDAO = moduleDefineHolder.find(StorageModule.NAME).provider().getService(StorageDAO.class);
          IMetricsDAO metricsDAO;
          try {
              metricsDAO = storageDAO.newMetricsDao(builder.getDeclaredConstructor().newInstance());
          } catch (InstantiationException | IllegalAccessException | NoSuchMethodException |
                   InvocationTargetException e) {
              throw new UnexpectedException("Create " + stream.getBuilder().getSimpleName() + " metrics DAO failure.", e);
          }
  
          ModelCreator modelSetter = moduleDefineHolder.find(CoreModule.NAME).provider().getService(ModelCreator.class);
          DownSamplingConfigService configService = moduleDefineHolder.find(CoreModule.NAME)
                                                                      .provider()
                                                                      .getService(DownSamplingConfigService.class);
  
          MetricsPersistentWorker hourPersistentWorker = null;
          MetricsPersistentWorker dayPersistentWorker = null;
  
          MetricsTransWorker transWorker = null;
  
          final MetricsExtension metricsExtension = metricsClass.getAnnotation(MetricsExtension.class);
          /**
           * All metrics default are `supportDownSampling` and `insertAndUpdate`, unless it has explicit definition.
           */
          boolean supportDownSampling = true;
          boolean supportUpdate = true;
          boolean timeRelativeID = true;
          if (metricsExtension != null) {
              supportDownSampling = metricsExtension.supportDownSampling();
              supportUpdate = metricsExtension.supportUpdate();
              timeRelativeID = metricsExtension.timeRelativeID();
          }
          if (supportDownSampling) {
              if (configService.shouldToHour()) {
                  Model model = modelSetter.add(
                      metricsClass, stream.getScopeId(), new Storage(stream.getName(), timeRelativeID, DownSampling.Hour)
                  );
                  hourPersistentWorker = downSamplingWorker(moduleDefineHolder, metricsDAO, model, supportUpdate, kind);
              }
              if (configService.shouldToDay()) {
                  Model model = modelSetter.add(
                      metricsClass, stream.getScopeId(), new Storage(stream.getName(), timeRelativeID, DownSampling.Day)
                  );
                  dayPersistentWorker = downSamplingWorker(moduleDefineHolder, metricsDAO, model, supportUpdate, kind);
              }
  
              transWorker = new MetricsTransWorker(
                  moduleDefineHolder, hourPersistentWorker, dayPersistentWorker);
          }
  
          Model model = modelSetter.add(
              metricsClass, stream.getScopeId(), new Storage(stream.getName(), timeRelativeID, DownSampling.Minute)
          );
          MetricsPersistentWorker minutePersistentWorker = minutePersistentWorker(
              moduleDefineHolder, metricsDAO, model, transWorker, supportUpdate, kind);
  
          String remoteReceiverWorkerName = stream.getName() + "_rec";
          IWorkerInstanceSetter workerInstanceSetter = moduleDefineHolder.find(CoreModule.NAME)
                                                                         .provider()
                                                                         .getService(IWorkerInstanceSetter.class);
          workerInstanceSetter.put(remoteReceiverWorkerName, minutePersistentWorker, metricsClass);
  
          MetricsRemoteWorker remoteWorker = new MetricsRemoteWorker(moduleDefineHolder, remoteReceiverWorkerName);
          MetricsAggregateWorker aggregateWorker = new MetricsAggregateWorker(
              moduleDefineHolder, remoteWorker, stream.getName(), l1FlushPeriod, kind);
  
          entryWorkers.put(metricsClass, aggregateWorker);
      }
  
      private MetricsPersistentWorker minutePersistentWorker(ModuleDefineHolder moduleDefineHolder,
                                                             IMetricsDAO metricsDAO,
                                                             Model model,
                                                             MetricsTransWorker transWorker,
                                                             boolean supportUpdate,
                                                             MetricStreamKind kind) {
          AlarmNotifyWorker alarmNotifyWorker = new AlarmNotifyWorker(moduleDefineHolder);
          ExportMetricsWorker exportWorker = new ExportMetricsWorker(moduleDefineHolder);
  
          MetricsPersistentWorker minutePersistentWorker = new MetricsPersistentWorker(
              moduleDefineHolder, model, metricsDAO, alarmNotifyWorker, exportWorker, transWorker,
              supportUpdate, storageSessionTimeout, metricsDataTTL, kind
          );
          persistentWorkers.add(minutePersistentWorker);
  
          return minutePersistentWorker;
      }
  
      private MetricsPersistentWorker downSamplingWorker(ModuleDefineHolder moduleDefineHolder,
                                                         IMetricsDAO metricsDAO,
                                                         Model model,
                                                         boolean supportUpdate,
                                                         MetricStreamKind kind) {
          MetricsPersistentWorker persistentWorker = new MetricsPersistentWorker(
              moduleDefineHolder, model, metricsDAO,
              supportUpdate, storageSessionTimeout, metricsDataTTL, kind
          );
          persistentWorkers.add(persistentWorker);
  
          return persistentWorker;
      }
  }
  