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.beam.sdk.util.construction;
  
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.function.Function;
  import org.apache.beam.model.expansion.v1.ExpansionApi;
  import org.apache.beam.model.expansion.v1.ExpansionServiceGrpc;
  import org.apache.beam.model.pipeline.v1.Endpoints;
  import org.apache.beam.vendor.grpc.v1p69p0.io.grpc.ManagedChannel;
  
  /** Default factory for ExpansionServiceClient used by External transform. */
  public class DefaultExpansionServiceClientFactory implements ExpansionServiceClientFactory {
    private Map<Endpoints.ApiServiceDescriptor, ExpansionServiceClient> expansionServiceMap;
    private Function<Endpoints.ApiServiceDescriptor, ManagedChannel> channelFactory;
  
    private DefaultExpansionServiceClientFactory(
        Function<Endpoints.ApiServiceDescriptor, ManagedChannel> channelFactory) {
      this.expansionServiceMap = new ConcurrentHashMap<>();
      this.channelFactory = channelFactory;
    }
  
    public static DefaultExpansionServiceClientFactory create(
        Function<Endpoints.ApiServiceDescriptor, ManagedChannel> channelFactory) {
      return new DefaultExpansionServiceClientFactory(channelFactory);
    }
  
    @Override
    public void close() throws Exception {
      for (ExpansionServiceClient client : expansionServiceMap.values()) {
        try (AutoCloseable closer = client) {}
      }
    }
  
    @Override
    public ExpansionServiceClient getExpansionServiceClient(Endpoints.ApiServiceDescriptor endpoint) {
      return expansionServiceMap.computeIfAbsent(
          endpoint,
          e ->
              new ExpansionServiceClient() {
                private final ManagedChannel channel = channelFactory.apply(endpoint);
                private final ExpansionServiceGrpc.ExpansionServiceBlockingStub service =
                    ExpansionServiceGrpc.newBlockingStub(channel);
  
                @Override
                public ExpansionApi.ExpansionResponse expand(ExpansionApi.ExpansionRequest request) {
                  return service.expand(request);
                }
  
                @Override
                public ExpansionApi.DiscoverSchemaTransformResponse discover(
                    ExpansionApi.DiscoverSchemaTransformRequest request) {
                  return service.discoverSchemaTransform(request);
                }
  
                @Override
                public void close() throws Exception {
                  channel.shutdown();
                }
              });
    }
  }
  