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;
  import org.apache.skywalking.oap.server.core.analysis.worker.NoneStreamProcessor;
  import org.apache.skywalking.oap.server.core.analysis.worker.RecordStreamProcessor;
  import org.apache.skywalking.oap.server.core.analysis.worker.TopNStreamProcessor;
  import org.apache.skywalking.oap.server.core.source.ScopeDeclaration;
  import org.apache.skywalking.oap.server.core.storage.type.StorageBuilder;
  
  /**
   * Stream annotation represents a metadata definition. Include the key values of the distributed streaming calculation.
   * See {@link MetricsStreamProcessor}, {@link RecordStreamProcessor}, {@link TopNStreamProcessor} and {@link
   * NoneStreamProcessor} for more details.
   */
  @Target(ElementType.TYPE)
  @Retention(RetentionPolicy.RUNTIME)
  public @interface Stream {
      /**
       * @return name of this stream definition.
       */
      String name();
  
      /**
       * @return scope id, see {@link ScopeDeclaration}
       */
      int scopeId();
  
      /**
       * @return the converter type between entity and storage record persistence. The converter could be override by the
       * storage implementation if necessary. Default, return {@link org.apache.skywalking.oap.server.core.storage.type.StorageBuilder}
       * for general suitable.
       */
      Class<? extends StorageBuilder> builder();
  
      /**
       * @return the stream processor type, see {@link MetricsStreamProcessor}, {@link RecordStreamProcessor},  {@link
       * TopNStreamProcessor} and {@link NoneStreamProcessor} for more details.
       */
      Class<? extends StreamProcessor> processor();
  }
  