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 static org.junit.Assert.assertArrayEquals;
  import static org.junit.Assert.assertEquals;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.nio.channels.SeekableByteChannel;
  import java.nio.channels.WritableByteChannel;
  import java.nio.charset.StandardCharsets;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.function.Consumer;
  import org.apache.beam.repackaged.core.org.apache.commons.compress.utils.SeekableInMemoryByteChannel;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.Parameterized;
  
  @RunWith(Parameterized.class)
  public class CountingChannelsWriteMethodsTest<ChannelT extends WritableByteChannel> {
    private ByteBuffer byteBuffer;
    private byte[] testData;
    private byte[] writtenData;
    private SeekableByteChannel delegate;
    private final ChannelUnderTestProvider<ChannelT> channelUnderTestProvider;
  
    public interface ChannelUnderTestProvider<T extends WritableByteChannel> {
      /**
       * Should create a delegating and counting {@link WritableByteChannel} whose write methods will
       * be tested.
       *
       * @param delegate a delegate to be used by the channel
       * @param bytesWrittenConsumer a consumer that is expected to receive the number of bytes
       *     written by the channel
       * @return the channel object to be tested
       */
      T create(SeekableByteChannel delegate, Consumer<Integer> bytesWrittenConsumer);
    }
  
    public CountingChannelsWriteMethodsTest(
        ChannelUnderTestProvider<ChannelT> channelUnderTestProvider,
        @SuppressWarnings("unused") String testLabel) {
      this.channelUnderTestProvider = channelUnderTestProvider;
    }
  
    private static <T extends WritableByteChannel> Object[] createTestCase(
        ChannelUnderTestProvider<T> channelUnderTestProvider, Class<T> channelClass) {
      return new Object[] {channelUnderTestProvider, channelClass.getSimpleName()};
    }
  
    private static Object[] createCountingSeekableByteChannelTestCase() {
      return createTestCase(
          CountingSeekableByteChannel::createWithBytesWrittenConsumer,
          CountingSeekableByteChannel.class);
    }
  
    private static Object[] createCountingWritableByteChannelTestCase() {
      return createTestCase(CountingWritableByteChannel::new, CountingWritableByteChannel.class);
    }
  
    @Parameterized.Parameters(name = "{1}")
    public static Iterable<Object[]> testCases() {
      ImmutableList.Builder<Object[]> builder = new ImmutableList.Builder<>();
      builder.add(createCountingSeekableByteChannelTestCase());
      builder.add(createCountingWritableByteChannelTestCase());
      return builder.build();
    }
  
    @Before
    public void before() {
      testData = "This is some test data".getBytes(StandardCharsets.UTF_8);
      byteBuffer = ByteBuffer.wrap(testData);
      writtenData = new byte[testData.length];
      delegate = new SeekableInMemoryByteChannel(writtenData);
    }
  
    @Test
    public void testCounting() throws IOException {
      AtomicInteger counter = new AtomicInteger();
      WritableByteChannel countingChannel =
          channelUnderTestProvider.create(delegate, counter::addAndGet);
  
      while (byteBuffer.remaining() != 0) {
        countingChannel.write(byteBuffer);
      }
  
      assertEquals(testData.length, counter.get());
    }
  
    @Test
    public void testWrite() throws IOException {
      WritableByteChannel channel = channelUnderTestProvider.create(delegate, __ -> {});
  
      while (byteBuffer.remaining() != 0) {
        channel.write(byteBuffer);
      }
  
      assertArrayEquals(testData, writtenData);
    }
  }
  