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 java.lang.annotation.ElementType;
  import java.lang.annotation.Retention;
  import java.lang.annotation.RetentionPolicy;
  import java.lang.annotation.Target;
  import org.apache.skywalking.oap.server.core.analysis.worker.MetricsStreamProcessor;
  
  /**
   * MetricsExtension annotation defines extension attributes of the {@link Stream} with {@link MetricsStreamProcessor}.
   */
  @Target(ElementType.TYPE)
  @Retention(RetentionPolicy.RUNTIME)
  public @interface MetricsExtension {
      /**
       * @return true if this metrics stream support down sampling.
       */
      boolean supportDownSampling();
  
      /**
       * @return true if this metrics data could be updated.
       */
      boolean supportUpdate();
  
      /**
       * @return true means the ID of this metric entity would generate timestamp related ID, such as 20170128-serviceId.
       * If as false, then, ID would be like serviceId directly. This is typically used for metadata level metric, such as
       * {@link org.apache.skywalking.oap.server.core.analysis.manual.service.ServiceTraffic}
       *
       * @since 9.4.0 `return false` could mean `not completely relevant`. Such as
       * {@link org.apache.skywalking.oap.server.core.analysis.manual.searchtag.TagAutocompleteData}
       * uses 20221108-tag-value as key, but time bucket is still in minute dimensionality, for example 202211081200.
       */
      boolean timeRelativeID() default false;
  }
  