content: /*
   * Copyright (C) 2020 ActiveJ LLC.
   *
   * Licensed 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 io.activej.datastream.supplier;
  
  import io.activej.datastream.consumer.ForwardingStreamConsumer;
  import io.activej.datastream.consumer.StreamConsumer;
  import io.activej.promise.Promise;
  
  /**
   * A wrapper class that delegates all calls to underlying {@link StreamSupplier}.
   * It exists for when one method of some supplier needs to be altered.
   */
  public abstract class ForwardingStreamSupplier<T> implements StreamSupplier<T> {
  	protected final StreamSupplier<T> supplier;
  
  	protected ForwardingStreamSupplier(StreamSupplier<T> supplier) {
  		this.supplier = supplier;
  	}
  
  	@Override
  	public Promise<Void> streamTo(StreamConsumer<T> consumer) {
  		return supplier.streamTo(new ForwardingStreamConsumer<>(consumer) {
  			@Override
  			public void consume(StreamSupplier<T> streamSupplier) {
  				super.consume(ForwardingStreamSupplier.this);
  			}
  		});
  	}
  
  	@Override
  	public Promise<Void> getAcknowledgement() {
  		return supplier.getAcknowledgement();
  	}
  
  	@Override
  	public void updateDataAcceptor() {
  		supplier.updateDataAcceptor();
  	}
  
  	@Override
  	public Promise<Void> getEndOfStream() {
  		return supplier.getEndOfStream();
  	}
  
  	@Override
  	public void closeEx(Exception e) {
  		supplier.closeEx(e);
  	}
  }
  