package org.eclipse.aether.internal.impl.synccontext;
   
   /*
    * 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.
   */
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.SyncContext;
  import org.eclipse.aether.internal.impl.synccontext.named.NamedLockFactoryAdapter;
  import org.eclipse.aether.internal.impl.synccontext.named.NamedLockFactoryAdapterFactory;
  import org.eclipse.aether.spi.locator.Service;
  import org.eclipse.aether.spi.locator.ServiceLocator;
  import org.eclipse.aether.spi.synccontext.SyncContextFactory;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Default {@link SyncContextFactory} implementation that uses named locks.
   * <p>
   * The implementation relies fully on {@link NamedLockFactoryAdapterFactory} and all it does is just "stuff" the
   * adapter instance into session, hence factory is called only when given session has no instance created.
   */
  @Singleton
  @Named
  public final class DefaultSyncContextFactory
          implements SyncContextFactory, Service
  {
      private static final String ADAPTER_KEY = DefaultSyncContextFactory.class.getName() + ".adapter";
  
      private NamedLockFactoryAdapterFactory namedLockFactoryAdapterFactory;
  
      /**
       * Constructor used with DI, where factories are injected and selected based on key.
       */
      @Inject
      public DefaultSyncContextFactory( final NamedLockFactoryAdapterFactory namedLockFactoryAdapterFactory )
      {
          this.namedLockFactoryAdapterFactory = requireNonNull( namedLockFactoryAdapterFactory );
      }
  
      /**
       * ServiceLocator default ctor.
       *
       * @deprecated Will be removed once ServiceLocator removed.
       */
      @Deprecated
      public DefaultSyncContextFactory()
      {
          // ctor for ServiceLoader
      }
  
      @Override
      public void initService( final ServiceLocator locator )
      {
          this.namedLockFactoryAdapterFactory = requireNonNull(
                  locator.getService( NamedLockFactoryAdapterFactory.class ) );
      }
  
      @Override
      public SyncContext newInstance( final RepositorySystemSession session, final boolean shared )
      {
          requireNonNull( session, "session cannot be null" );
          NamedLockFactoryAdapter adapter = (NamedLockFactoryAdapter) session.getData().computeIfAbsent(
                  ADAPTER_KEY, () -> namedLockFactoryAdapterFactory.getAdapter( session ) );
          return adapter.newInstance( session, shared );
      }
  }