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.kafka.common.record;
  
  import org.apache.kafka.common.KafkaException;
  import org.apache.kafka.common.network.Send;
  import org.apache.kafka.common.network.TransferableChannel;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.util.Queue;
  
  /**
   * A set of composite sends with nested {@link RecordsSend}, sent one after another
   */
  public class MultiRecordsSend implements Send {
      private static final Logger log = LoggerFactory.getLogger(MultiRecordsSend.class);
  
      private final Queue<Send> sendQueue;
      private final long size;
  
      private long totalWritten = 0;
      private Send current;
  
      /**
       * Construct a MultiRecordsSend from a queue of Send objects. The queue will be consumed as the MultiRecordsSend
       * progresses (on completion, it will be empty).
       */
      public MultiRecordsSend(Queue<Send> sends) {
          this.sendQueue = sends;
  
          long size = 0;
          for (Send send : sends)
              size += send.size();
          this.size = size;
  
          this.current = sendQueue.poll();
      }
  
      public MultiRecordsSend(Queue<Send> sends, long size) {
          this.sendQueue = sends;
          this.size = size;
          this.current = sendQueue.poll();
      }
  
      @Override
      public long size() {
          return size;
      }
  
      @Override
      public boolean completed() {
          return current == null;
      }
  
      // Visible for testing
      int numResidentSends() {
          int count = 0;
          if (current != null)
              count += 1;
          count += sendQueue.size();
          return count;
      }
  
      @Override
      public long writeTo(TransferableChannel channel) throws IOException {
          if (completed())
              throw new KafkaException("This operation cannot be invoked on a complete request.");
  
          long totalWrittenPerCall = 0;
          boolean sendComplete;
          do {
              long written = current.writeTo(channel);
              totalWrittenPerCall += written;
              sendComplete = current.completed();
              if (sendComplete) {
                  current = sendQueue.poll();
              }
          } while (!completed() && sendComplete);
  
          totalWritten += totalWrittenPerCall;
  
          if (completed() && totalWritten != size)
              log.error("mismatch in sending bytes over socket; expected: {} actual: {}", size, totalWritten);
  
          log.trace("Bytes written as part of multi-send call: {}, total bytes written so far: {}, expected bytes to write: {}",
                  totalWrittenPerCall, totalWritten, size);
  
          return totalWrittenPerCall;
      }
  
      @Override
      public String toString() {
          return "MultiRecordsSend(" +
              "size=" + size +
              ", totalWritten=" + totalWritten +
              ')';
      }
  }
  