code: /*
   * Copyright 2022 Mitsunori Komatsu (komamitsu)
   *
   * 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 org.komamitsu.fluency.fluentd.ingester.sender;
  
  import org.komamitsu.fluency.fluentd.ingester.sender.failuredetect.FailureDetector;
  import org.komamitsu.fluency.validation.Validatable;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.net.SocketException;
  import java.net.UnixDomainSocketAddress;
  import java.nio.ByteBuffer;
  import java.nio.channels.SocketChannel;
  import java.nio.file.Path;
  import java.util.List;
  import java.util.concurrent.atomic.AtomicReference;
  
  public class UnixSocketSender
          extends NetworkSender<SocketChannel>
  {
      private static final Logger LOG = LoggerFactory.getLogger(UnixSocketSender.class);
      private final AtomicReference<SocketChannel> channel = new AtomicReference<>();
      private final Config config;
  
      public UnixSocketSender()
      {
          this(new Config());
      }
  
      public UnixSocketSender(Config config)
      {
          this(config, null);
      }
  
      public UnixSocketSender(FailureDetector failureDetector)
      {
          this(new Config(), failureDetector);
      }
  
      public UnixSocketSender(Config config, FailureDetector failureDetector)
      {
          super(config, failureDetector);
          config.validateValues();
          this.config = config;
      }
  
      @Override
      protected SocketChannel getOrCreateSocketInternal()
              throws IOException
      {
          if (channel.get() == null) {
              UnixDomainSocketAddress socketAddress = UnixDomainSocketAddress.of(config.getPath());
              channel.set(SocketChannel.open(socketAddress));
          }
          return channel.get();
      }
  
      public Path getPath()
      {
          return config.getPath();
      }
  
      @Override
      protected void sendBuffers(SocketChannel socketChannel, List<ByteBuffer> buffers)
              throws IOException
      {
          socketChannel.write(buffers.toArray(new ByteBuffer[0]));
      }
  
      @Override
      protected void recvResponse(SocketChannel socketChannel, ByteBuffer buffer)
              throws IOException
      {
          int read = socketChannel.read(buffer);
          if (read < 0) {
              throw new SocketException("The connection is disconnected by the peer");
          }
      }
  
      @Override
      protected void closeSocket()
              throws IOException
      {
          SocketChannel existingSocketChannel;
          if ((existingSocketChannel = channel.getAndSet(null)) != null) {
              existingSocketChannel.close();
          }
      }
  
      @Override
      public String toString()
      {
          return "UnixSocketSender{" +
                  "config=" + config +
                  "} " + super.toString();
      }
  
      public static class Config
              extends NetworkSender.Config
              implements Validatable
      {
          private Path path;
  
          void validateValues()
          {
              validate();
          }
  
          public Path getPath()
          {
              return path;
          }
  
          public void setPath(Path path)
          {
              this.path = path;
          }
  
          @Override
          public String toString() {
              return "Config{" +
                      "path=" + path +
                      "} " + super.toString();
          }
      }
  }
  