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.asterix.replication.messaging;
  
  import java.io.DataInput;
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.nio.ByteBuffer;
  
  import org.apache.asterix.common.api.INcApplicationContext;
  import org.apache.asterix.common.exceptions.ReplicationException;
  import org.apache.asterix.common.transactions.ILogManager;
  import org.apache.asterix.replication.api.IReplicaTask;
  import org.apache.asterix.replication.api.IReplicationWorker;
  import org.apache.asterix.replication.logging.RemoteLogRecord;
  import org.apache.asterix.replication.logging.RemoteLogsProcessor;
  import org.apache.asterix.replication.management.ReplicationChannel;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.api.network.ISocketChannel;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  /**
   * A task to replicate transaction logs from master replica
   */
  public class ReplicateLogsTask implements IReplicaTask {
  
      private static final Logger LOGGER = LogManager.getLogger();
      public static final int END_REPLICATION_LOG_SIZE = 1;
      private final String nodeId;
  
      public ReplicateLogsTask(String nodeId) {
          this.nodeId = nodeId;
      }
  
      @Override
      public void perform(INcApplicationContext appCtx, IReplicationWorker worker) {
          final ReplicationChannel replicationChannel = (ReplicationChannel) appCtx.getReplicationChannel();
          final RemoteLogsProcessor logsProcessor = replicationChannel.getRemoteLogsProcessor();
          final ILogManager logManager = appCtx.getTransactionSubsystem().getLogManager();
          final RemoteLogRecord reusableLog = new RemoteLogRecord();
          final ISocketChannel channel = worker.getChannel();
          ByteBuffer logsBuffer = ByteBuffer.allocate(logManager.getLogPageSize());
          try {
              while (true) {
                  // read a batch of logs
                  logsBuffer = ReplicationProtocol.readRequest(channel, logsBuffer);
                  // check if it is end of handshake
                  if (logsBuffer.remaining() == END_REPLICATION_LOG_SIZE) {
                      LOGGER.debug("ending log replication with {}", worker.getRemoteAddress());
                      break;
                  }
                  logsProcessor.process(logsBuffer, reusableLog, worker);
              }
          } catch (IOException e) {
              throw new ReplicationException(e);
          }
      }
  
      @Override
      public ReplicationProtocol.ReplicationRequestType getMessageType() {
          return ReplicationProtocol.ReplicationRequestType.REPLICATE_LOGS;
      }
  
      @Override
      public void serialize(OutputStream out) throws HyracksDataException {
          try {
              DataOutputStream dos = new DataOutputStream(out);
              dos.writeUTF(nodeId);
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
      }
  
      public static ReplicateLogsTask create(DataInput input) throws IOException {
          final String node = input.readUTF();
          return new ReplicateLogsTask(node);
      }
  }
  