/**
    * 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.client;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.util.ReflectionUtils;
  
  /**
   * Factory to create an {@link RpcRetryingCaller}
   */
  @InterfaceAudience.Private
  public class RpcRetryingCallerFactory {
  
    /** Configuration key for a custom {@link RpcRetryingCaller} */
    public static final String CUSTOM_CALLER_CONF_KEY = "hbase.rpc.callerfactory.class";
    protected final Configuration conf;
    private final long pause;
    private final int retries;
    private final int rpcTimeout;
    private final RetryingCallerInterceptor interceptor;
    private final int startLogErrorsCnt;
    private final boolean enableBackPressure;
    private ServerStatisticTracker stats;
  
    public RpcRetryingCallerFactory(Configuration conf) {
      this(conf, RetryingCallerInterceptorFactory.NO_OP_INTERCEPTOR);
    }
    
    public RpcRetryingCallerFactory(Configuration conf, RetryingCallerInterceptor interceptor) {
      this.conf = conf;
      pause = conf.getLong(HConstants.HBASE_CLIENT_PAUSE,
          HConstants.DEFAULT_HBASE_CLIENT_PAUSE);
      retries = conf.getInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER,
          HConstants.DEFAULT_HBASE_CLIENT_RETRIES_NUMBER);
      startLogErrorsCnt = conf.getInt(AsyncProcess.START_LOG_ERRORS_AFTER_COUNT_KEY,
          AsyncProcess.DEFAULT_START_LOG_ERRORS_AFTER_COUNT);
      this.interceptor = interceptor;
      enableBackPressure = conf.getBoolean(HConstants.ENABLE_CLIENT_BACKPRESSURE,
          HConstants.DEFAULT_ENABLE_CLIENT_BACKPRESSURE);
      rpcTimeout = conf.getInt(HConstants.HBASE_RPC_TIMEOUT_KEY,HConstants.DEFAULT_HBASE_RPC_TIMEOUT);
    }
  
    /**
     * Set the tracker that should be used for tracking statistics about the server
     */
    public void setStatisticTracker(ServerStatisticTracker statisticTracker) {
      this.stats = statisticTracker;
    }
  
    /**
     * Create a new RetryingCaller with specific rpc timeout.
     */
    public <T> RpcRetryingCaller<T> newCaller(int rpcTimeout) {
      // We store the values in the factory instance. This way, constructing new objects
      //  is cheap as it does not require parsing a complex structure.
      RpcRetryingCaller<T> caller = new RpcRetryingCaller<T>(pause, retries, interceptor,
          startLogErrorsCnt, rpcTimeout);
  
      // wrap it with stats, if we are tracking them
      if (enableBackPressure && this.stats != null) {
        caller = new StatsTrackingRpcRetryingCaller<T>(pause, retries, interceptor,
            startLogErrorsCnt, stats);
      }
  
      return caller;
    }
  
    /**
     * Create a new RetryingCaller with configured rpc timeout.
     */
    public <T> RpcRetryingCaller<T> newCaller() {
      // We store the values in the factory instance. This way, constructing new objects
      //  is cheap as it does not require parsing a complex structure.
      RpcRetryingCaller<T> caller = new RpcRetryingCaller<T>(pause, retries, interceptor,
          startLogErrorsCnt, rpcTimeout);
  
      // wrap it with stats, if we are tracking them
      if (enableBackPressure && this.stats != null) {
        caller = new StatsTrackingRpcRetryingCaller<T>(pause, retries, interceptor,
            startLogErrorsCnt, stats);
      }
  
     return caller;
   }
 
   public static RpcRetryingCallerFactory instantiate(Configuration configuration) {
     return instantiate(configuration, RetryingCallerInterceptorFactory.NO_OP_INTERCEPTOR, null);
   }
 
   public static RpcRetryingCallerFactory instantiate(Configuration configuration,
       ServerStatisticTracker stats) {
     return instantiate(configuration, RetryingCallerInterceptorFactory.NO_OP_INTERCEPTOR, stats);
   }
 
   public static RpcRetryingCallerFactory instantiate(Configuration configuration,
       RetryingCallerInterceptor interceptor, ServerStatisticTracker stats) {
     String clazzName = RpcRetryingCallerFactory.class.getName();
     String rpcCallerFactoryClazz =
         configuration.get(RpcRetryingCallerFactory.CUSTOM_CALLER_CONF_KEY, clazzName);
     RpcRetryingCallerFactory factory;
     if (rpcCallerFactoryClazz.equals(clazzName)) {
       factory = new RpcRetryingCallerFactory(configuration, interceptor);
     } else {
       factory = ReflectionUtils.instantiateWithCustomCtor(
           rpcCallerFactoryClazz, new Class[] { Configuration.class },
           new Object[] { configuration });
     }
 
     // setting for backwards compat with existing caller factories, rather than in the ctor
     factory.setStatisticTracker(stats);
     return factory;
   }
 }