code: /*
   * Copyright 2019 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.retry.RetryStrategy;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.util.List;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  public class RetryableSender
          extends FluentdSender
  {
      private static final Logger LOG = LoggerFactory.getLogger(RetryableSender.class);
      private final FluentdSender baseSender;
      private final AtomicBoolean isClosed = new AtomicBoolean();
      private RetryStrategy retryStrategy;
  
      public RetryableSender(FluentdSender baseSender, RetryStrategy retryStrategy)
      {
          this(new Config(), baseSender, retryStrategy);
      }
  
      public RetryableSender(Config config, FluentdSender baseSender, RetryStrategy retryStrategy)
      {
          super(config);
          this.baseSender = baseSender;
          this.retryStrategy = retryStrategy;
      }
  
      @Override
      public void close()
              throws IOException
      {
          baseSender.close();
          isClosed.set(true);
      }
  
      @Override
      public boolean isAvailable()
      {
          return true;
      }
  
      @Override
      protected synchronized void sendInternal(List<ByteBuffer> buffers, String ackToken)
              throws IOException
      {
          IOException firstException = null;
  
          int retry = 0;
          while (!retryStrategy.isRetriedOver(retry)) {
              if (isClosed.get()) {
                  throw new RetryOverException("This sender is already closed", firstException);
              }
  
              try {
                  if (ackToken == null) {
                      baseSender.send(buffers);
                  }
                  else {
                      baseSender.sendWithAck(buffers, ackToken);
                  }
                  return;
              }
              catch (IOException e) {
                  firstException = e;
                  LOG.warn("Sender failed to send data. sender=" + this + ", retry=" + retry, e);
              }
  
              try {
                  TimeUnit.MILLISECONDS.sleep(retryStrategy.getNextIntervalMillis(retry));
              }
              catch (InterruptedException e) {
                  LOG.debug("Interrupted while waiting", e);
                  Thread.currentThread().interrupt();
              }
              retry++;
          }
  
          throw new RetryOverException("Sending data was retried over", firstException);
      }
  
      public FluentdSender getBaseSender()
      {
          return baseSender;
      }
  
      public RetryStrategy getRetryStrategy()
      {
          return retryStrategy;
      }
  
      public boolean isClosed()
      {
          return isClosed.get();
      }
  
      @Override
      public String toString()
      {
          return "RetryableSender{" +
                  "baseSender=" + baseSender +
                  ", retryStrategy=" + retryStrategy +
                  ", isClosed=" + isClosed +
                  "} " + super.toString();
      }
  
      public static class RetryOverException
              extends IOException
      {
          public RetryOverException(String s, Throwable throwable)
          {
              super(s, throwable);
          }
      }
  
      public static class Config
              extends FluentdSender.Config
      {
      }
  }
  