content: /*
   * 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.bifromq.baserpc.server;
  
  import org.apache.bifromq.baserpc.RPCContext;
  import org.apache.bifromq.baserpc.metrics.IRPCMeter;
  import io.grpc.stub.ServerCallStreamObserver;
  import io.grpc.stub.StreamObserver;
  import java.util.Map;
  import lombok.extern.slf4j.Slf4j;
  
  @Slf4j
  public abstract class AbstractStreamObserver<InT, OutT> implements StreamObserver<InT> {
      protected final String tenantId;
      protected final Map<String, String> metadata;
      protected final ServerCallStreamObserver<OutT> responseObserver;
      protected final IRPCMeter.IRPCMethodMeter meter;
  
      protected AbstractStreamObserver(StreamObserver<OutT> responseObserver) {
          tenantId = RPCContext.TENANT_ID_CTX_KEY.get();
          metadata = RPCContext.CUSTOM_METADATA_CTX_KEY.get();
          meter = RPCContext.METER_KEY_CTX_KEY.get();
          this.responseObserver = (ServerCallStreamObserver<OutT>) responseObserver;
          log.trace("Pipeline@{} created: tenantId={}", hashCode(), tenantId);
      }
  
      public final Map<String, String> metadata() {
          return metadata;
      }
  
      public final String metadata(String key) {
          return metadata.get(key);
      }
  
      public final boolean hasMetadata(String key) {
          return metadata.containsKey(key);
      }
  
      public abstract void close();
  }
  