/**
    * 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.hadoop.hbase.ipc;
  
  import java.util.List;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.CellScannable;
  import org.apache.hadoop.hbase.CellScanner;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.util.ReflectionUtils;
  
  /**
   * Factory to create a {@link PayloadCarryingRpcController}
   */
  @InterfaceAudience.Private
  public class RpcControllerFactory {
    private static final Log LOG = LogFactory.getLog(RpcControllerFactory.class);
  
    /**
     * Custom RPC Controller factory allows frameworks to change the RPC controller. If the configured
     * controller cannot be found in the classpath or loaded, we fall back to the default RPC
     * controller factory.
     */
    public static final String CUSTOM_CONTROLLER_CONF_KEY = "hbase.rpc.controllerfactory.class";
    protected final Configuration conf;
  
    public RpcControllerFactory(Configuration conf) {
      this.conf = conf;
    }
  
    public PayloadCarryingRpcController newController() {
      return new PayloadCarryingRpcController();
    }
  
    public PayloadCarryingRpcController newController(final CellScanner cellScanner) {
      return new PayloadCarryingRpcController(cellScanner);
    }
  
    public PayloadCarryingRpcController newController(final List<CellScannable> cellIterables) {
      return new PayloadCarryingRpcController(cellIterables);
    }
  
  
    public static RpcControllerFactory instantiate(Configuration configuration) {
      String rpcControllerFactoryClazz =
          configuration.get(CUSTOM_CONTROLLER_CONF_KEY,
            RpcControllerFactory.class.getName());
      try {
        return ReflectionUtils.instantiateWithCustomCtor(rpcControllerFactoryClazz,
          new Class[] { Configuration.class }, new Object[] { configuration });
      } catch (UnsupportedOperationException | NoClassDefFoundError ex) {
        // HBASE-14960: In case the RPCController is in a non-HBase jar (Phoenix), but the application
        // is a pure HBase application, we want to fallback to the default one.
        String msg = "Cannot load configured \"" + CUSTOM_CONTROLLER_CONF_KEY + "\" ("
            + rpcControllerFactoryClazz + ") from hbase-site.xml, falling back to use "
            + "default RpcControllerFactory";
        if (LOG.isDebugEnabled()) {
          LOG.warn(msg, ex); // if DEBUG enabled, we want the exception, but still log in WARN level
        } else {
          LOG.warn(msg);
        }
        return new RpcControllerFactory(configuration);
      }
    }
  }