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.runners.dataflow.worker;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.ServiceLoader;
  import java.util.Set;
  import org.apache.beam.runners.dataflow.util.CloudObject;
  import org.apache.beam.runners.dataflow.worker.util.common.worker.Sink;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.util.common.ReflectHelpers;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableMap;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Lists;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Sets;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  /**
   * An immutable registry from {@link String} identifiers (provided to the worker by the Dataflow
   * service) to appropriate {@link SinkFactory} instances.
   */
  @SuppressWarnings({
    "rawtypes", // TODO(https://github.com/apache/beam/issues/20447)
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  public final class SinkRegistry implements SinkFactory {
  
    /**
     * A {@link SinkRegistry} with each {@link SinkFactory} known to the Dataflow worker already
     * registered.
     *
     * <p>Uses {@link ServiceLoader} to dynamically bind well known types to sink factories via {@link
     * SinkFactory.Registrar}.
     */
    public static SinkRegistry defaultRegistry() {
      Set<SinkFactory.Registrar> readerFactoryRegistrars =
          Sets.newTreeSet(ReflectHelpers.ObjectsClassComparator.INSTANCE);
      readerFactoryRegistrars.addAll(
          Lists.newArrayList(
              ServiceLoader.load(SinkFactory.Registrar.class, ReflectHelpers.findClassLoader())));
  
      ImmutableMap.Builder<String, SinkFactory> factories = ImmutableMap.builder();
      for (SinkFactory.Registrar registrar : readerFactoryRegistrars) {
        factories.putAll(registrar.factories());
      }
      return new SinkRegistry(factories.build());
    }
  
    /** Builds a new {@link SinkRegistry} with the provided mappings. */
    private SinkRegistry(Map<String, SinkFactory> factories) {
      this.factories = factories;
    }
  
    /** A map from the short names of predefined sinks to the associated {@link SinkFactory}. */
    private final Map<String, SinkFactory> factories;
  
    /**
     * Returns a new {@link SinkRegistry} with the provided identifier associated with the provided
     * {@link SinkFactory}, overriding any existing binding for that identifier.
     */
    public SinkRegistry register(String readerSpecType, SinkFactory factory) {
      Map<String, SinkFactory> newFactories = new HashMap<>();
      newFactories.putAll(factories);
      newFactories.put(readerSpecType, factory);
      return new SinkRegistry(newFactories);
    }
  
    /**
     * Creates a {@link Sink} from a Dataflow API Sink definition. It wraps the sink from the factory
     * in a {@link SizeReportingSinkWrapper}.
     *
     * @throws Exception if the sink could not be decoded and constructed
     */
    @Override
    public SizeReportingSinkWrapper<?> create(
        CloudObject sinkSpec,
        Coder<?> coder,
        @Nullable PipelineOptions options,
        @Nullable DataflowExecutionContext executionContext,
        DataflowOperationContext operationContext)
        throws Exception {
  
      String objClassName = sinkSpec.getClassName();
  
      SinkFactory factory = factories.get(objClassName);
      if (factory == null) {
        throw new IllegalArgumentException(
            String.format(
                "Unable to create a Sink: Unknown Sink type in specification: %s", objClassName));
      }
  
      Sink<?> sink = factory.create(sinkSpec, coder, options, executionContext, operationContext);
      @SuppressWarnings("unchecked")
      Sink<Object> typedSink = (Sink<Object>) sink;
      return new SizeReportingSinkWrapper<>(typedSink, executionContext);
    }
  }
  