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 com.alibaba.wasp.client;
  
  import com.alibaba.wasp.ReadModel;
  import com.alibaba.wasp.ServerName;
  import com.alibaba.wasp.protobuf.ProtobufUtil;
  import com.alibaba.wasp.protobuf.RequestConverter;
  import com.alibaba.wasp.protobuf.generated.ClientProtos.ExecuteRequest;
  import com.alibaba.wasp.protobuf.generated.ClientProtos.ExecuteResponse;
  import com.google.protobuf.ServiceException;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.util.List;
  import java.util.Random;
  
  public class FClientCallable extends ServerCallable<ExecuteResponse> implements
      Closeable {
  
    /** FServer tracker **/
    private FClientFServerTracker fserverTracker;
  
    /** rand for client request. **/
    private Random rand = new Random();
  
    private final String sql;
  
    private int fetchSize;
  
    private final ReadModel model;
  
    private String sessionId;
  
    private boolean isTransaction = false;
  
    private List<String> sqls;
  
    /**
     * @param connection
     * @param fserverTracker
     * @param sql
     * @param model
     * @throws java.io.IOException
     */
    public FClientCallable(FConnection connection,
        FClientFServerTracker fserverTracker, String sql, ReadModel model,
        int fetchSize) throws IOException {
      super(connection, null, null);
      this.fserverTracker = fserverTracker;
      this.sql = sql;
      this.model = model;
      this.fetchSize = fetchSize;
    }
  
     /**
     * @param connection
     * @param fserverTracker
     * @param sql
     * @param model
     * @throws java.io.IOException
     */
    public FClientCallable(FConnection connection,
        FClientFServerTracker fserverTracker, String sql, ReadModel model,
        int fetchSize, String sessionId) throws IOException {
      super(connection, null, null);
      this.fserverTracker = fserverTracker;
      this.sql = sql;
      this.model = model;
      this.fetchSize = fetchSize;
      this.sessionId = sessionId;
    }
  
    public FClientCallable(FConnection connection, FClientFServerTracker fserverTracker,
                           List<String> sqls, boolean isTransaction, String sessionId) {
      super(connection, null, null);
      this.sql = null;
      this.model = null;
      this.fserverTracker = fserverTracker;
      this.sessionId = sessionId;
      this.isTransaction = isTransaction;
      this.sqls = sqls;
    }
  
    /**
     * Connect to the server hosting entityGroup with row from tablename.
     * 
     * @param reload
     *          Set this to true if connection should re-find the entityGroup
     * @throws java.io.IOException
     *           e
     */
    public void connect(final boolean reload) throws IOException {
      if (server == null || reload) {
        List<ServerName> sns = fserverTracker.getOnlineServers();
        ServerName sn = sns.get(rand.nextInt(sns.size()));
        this.server = connection.getClient(sn.getHostname(), sn.getPort());
      }
    }
  
    /**
     * @see java.util.concurrent.Callable#call()
     */
    @Override
    public ExecuteResponse call() throws IOException {
      ExecuteRequest request = null;
      if(isTransaction) {
        request = RequestConverter.buildExecuteRequest(sqls, sessionId, true);
      } else {
        request = RequestConverter.buildExecuteRequest(sql, model, fetchSize, sessionId);
      }
      try {
        ExecuteResponse response = server.execute(null, request);
        sessionId = response.getSessionId();
        return response;
      } catch (ServiceException e) {
        throw ProtobufUtil.getRemoteException(e);
      }
    }
  
    /**
     * Close
     */
    @Override
    public void close() throws IOException {
      if (sessionId != null) {
        ExecuteRequest request = RequestConverter.buildExecuteRequest(sessionId,
            sql, true);
        try {
          server.execute(null, request);
        } catch (ServiceException e) {
          throw ProtobufUtil.getRemoteException(e);
        }
      }
    }
  }