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.extensions.gcp.util.channels;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.nio.channels.WritableByteChannel;
  import java.util.function.Consumer;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.annotations.VisibleForTesting;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions;
  
  public class CountingWritableByteChannel implements WritableByteChannel {
    private final WritableByteChannel delegate;
    private final Consumer<Integer> bytesWrittenConsumer;
  
    // since it's equivalent to directly using the delegate, there's no point in using this variant
    // elsewhere than in tests
    @VisibleForTesting
    public static CountingWritableByteChannel createWithNoOpConsumer(WritableByteChannel delegate) {
      return new CountingWritableByteChannel(delegate, __ -> {});
    }
  
    public CountingWritableByteChannel(
        WritableByteChannel delegate, Consumer<Integer> bytesWrittenConsumer) {
      this.delegate = Preconditions.checkNotNull(delegate);
      this.bytesWrittenConsumer = Preconditions.checkNotNull(bytesWrittenConsumer);
    }
  
    @Override
    public int write(ByteBuffer src) throws IOException {
      int bytesWritten = delegate.write(src);
      bytesWrittenConsumer.accept(bytesWritten);
      return bytesWritten;
    }
  
    @Override
    public boolean isOpen() {
      return delegate.isOpen();
    }
  
    @Override
    public void close() throws IOException {
      delegate.close();
    }
  }
  