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.query;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Set;
  import java.util.concurrent.TimeUnit;
  import java.util.stream.Collectors;
  
  import com.google.common.cache.CacheBuilder;
  import com.google.common.cache.CacheLoader;
  import com.google.common.cache.LoadingCache;
  import lombok.SneakyThrows;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.skywalking.oap.server.core.Const;
  import org.apache.skywalking.oap.server.core.CoreModuleConfig;
  import org.apache.skywalking.oap.server.core.analysis.DownSampling;
  import org.apache.skywalking.oap.server.core.analysis.IDManager;
  import org.apache.skywalking.oap.server.core.analysis.Layer;
  import org.apache.skywalking.oap.server.core.analysis.TimeBucket;
  import org.apache.skywalking.oap.server.core.query.enumeration.ProfilingSupportStatus;
  import org.apache.skywalking.oap.server.core.query.input.Duration;
  import org.apache.skywalking.oap.server.core.query.type.Endpoint;
  import org.apache.skywalking.oap.server.core.query.type.EndpointInfo;
  import org.apache.skywalking.oap.server.core.query.type.Process;
  import org.apache.skywalking.oap.server.core.query.type.Service;
  import org.apache.skywalking.oap.server.core.query.type.ServiceInstance;
  import org.apache.skywalking.oap.server.core.storage.StorageModule;
  import org.apache.skywalking.oap.server.core.storage.query.IMetadataQueryDAO;
  import org.apache.skywalking.oap.server.library.module.ModuleManager;
  import org.apache.skywalking.oap.server.library.util.CollectionUtils;
  
  public class MetadataQueryService implements org.apache.skywalking.oap.server.library.module.Service {
  
      private final ModuleManager moduleManager;
      private final LoadingCache<Boolean, Map<String, List<Service>>> serviceCache;
      private IMetadataQueryDAO metadataQueryDAO;
  
      public MetadataQueryService(ModuleManager moduleManager, CoreModuleConfig moduleConfig) {
          this.moduleManager = moduleManager;
  
          this.serviceCache = CacheBuilder.newBuilder()
              .maximumSize(1)
              .refreshAfterWrite(moduleConfig.getServiceCacheRefreshInterval(), TimeUnit.SECONDS)
              .build(new CacheLoader<>() {
                  @Override
                  public Map<String, List<Service>> load(Boolean key) throws Exception {
                      return mapAllServices();
                  }
              });
      }
  
      private IMetadataQueryDAO getMetadataQueryDAO() {
          if (metadataQueryDAO == null) {
              metadataQueryDAO = moduleManager.find(StorageModule.NAME).provider().getService(IMetadataQueryDAO.class);
          }
          return metadataQueryDAO;
      }
  
      public Set<String> listLayers() throws IOException {
          return Arrays.stream(Layer.values()).filter(layer -> layer.value() > 0).map(Layer::name).collect(Collectors.toSet());
      }
  
      @SneakyThrows
      public List<Service> listServices(final String layer, final String group) throws IOException {
          return this.combineServices(this.serviceCache.get(true).values().stream().flatMap(Collection::stream)
              .filter(svc -> {
                  if (StringUtils.isNotEmpty(layer) && !svc.getLayers().contains(layer)) {
                      return false;
                  }
                  return StringUtils.isEmpty(group) || Objects.equals(svc.getGroup(), group);
              }).collect(Collectors.toList()));
      }
  
      @SneakyThrows
      public Service getService(final String serviceId) throws IOException {
          final List<Service> services = this.combineServices(this.serviceCache.get(true).get(serviceId));
          return CollectionUtils.isNotEmpty(services) ? services.get(0) : null;
      }
  
      public ServiceInstance getInstance(final String instanceId) throws IOException {
          return getMetadataQueryDAO().getInstance(instanceId);
      }
  
      public List<ServiceInstance> listInstances(final Duration duration,
                                                       final String serviceId) throws IOException {
          return getMetadataQueryDAO().listInstances(duration, serviceId)
                                      .stream().distinct().collect(Collectors.toList());
      }
  
      public List<Endpoint> findEndpoint(final String keyword, final String serviceId,
                                         final int limit) throws IOException {
          return getMetadataQueryDAO().findEndpoint(keyword, serviceId, limit)
                                      .stream().distinct().collect(Collectors.toList());
      }
  
      public EndpointInfo getEndpointInfo(final String endpointId) throws IOException {
          final IDManager.EndpointID.EndpointIDDefinition endpointIDDefinition = IDManager.EndpointID.analysisId(
              endpointId);
          final IDManager.ServiceID.ServiceIDDefinition serviceIDDefinition = IDManager.ServiceID.analysisId(
              endpointIDDefinition.getServiceId());
  
          EndpointInfo endpointInfo = new EndpointInfo();
          endpointInfo.setId(endpointId);
          endpointInfo.setName(endpointIDDefinition.getEndpointName());
          endpointInfo.setServiceId(endpointIDDefinition.getServiceId());
          endpointInfo.setServiceName(serviceIDDefinition.getName());
          return endpointInfo;
      }
  
      public List<Process> listProcesses(final Duration duration, final String instanceId) throws IOException {
          if (duration.getEndTimeBucket() < duration.getStartTimeBucket()) {
              return Collections.emptyList();
          }
          return getMetadataQueryDAO().listProcesses(instanceId, duration, true);
      }
  
      public Process getProcess(String processId) throws IOException {
          if (StringUtils.isEmpty(processId)) {
              return null;
          }
          return getMetadataQueryDAO().getProcess(processId);
      }
  
      public Long estimateProcessScale(String serviceId, List<String> labels) throws IOException {
          if (StringUtils.isEmpty(serviceId)) {
              return 0L;
          }
          final long endTimestamp = System.currentTimeMillis();
          final long startTimestamp = endTimestamp - TimeUnit.MINUTES.toMillis(10);
          final List<Process> processes = getMetadataQueryDAO().listProcesses(serviceId,
                  ProfilingSupportStatus.SUPPORT_EBPF_PROFILING, TimeBucket.getTimeBucket(startTimestamp, DownSampling.Minute),
                  TimeBucket.getTimeBucket(endTimestamp, DownSampling.Minute));
          return CollectionUtils.isEmpty(processes) ?
                  0L :
                  processes.stream().filter(p -> p.getLabels().containsAll(labels)).count();
      }
  
      private Map<String, List<Service>> mapAllServices() throws Exception {
          final List<Service> services = getMetadataQueryDAO().listServices();
          return services.stream().peek(service -> {
              if (service.getGroup() == null) {
                  service.setGroup(Const.EMPTY_STRING);
              }
          }).collect(Collectors.toMap(Service::getId, s -> new ArrayList<>(List.of(s)), (s1, s2) -> {
              s1.addAll(s2);
              return s1;
          }));
      }
  
      private List<Service> combineServices(List<Service> services) {
          if (CollectionUtils.isEmpty(services)) {
              return Collections.emptyList();
          }
          return new ArrayList<>(services.stream()
                                         .collect(Collectors.toMap(Service::getName, service -> service,
                                                                   (s1, s2) -> {
                                                                       s1.getLayers().addAll(s2.getLayers());
                                                                       return s1;
                                                                   }
                                         )).values());
      }
  }
  