/*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project 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.jboss.netty.channel.socket.nio;
  
  import java.net.Socket;
  import java.util.Map;
  
  import org.jboss.netty.channel.AdaptiveReceiveBufferSizePredictorFactory;
  import org.jboss.netty.channel.ChannelException;
  import org.jboss.netty.channel.ReceiveBufferSizePredictor;
  import org.jboss.netty.channel.ReceiveBufferSizePredictorFactory;
  import org.jboss.netty.channel.socket.DefaultSocketChannelConfig;
  import org.jboss.netty.logging.InternalLogger;
  import org.jboss.netty.logging.InternalLoggerFactory;
  import org.jboss.netty.util.internal.ConversionUtil;
  
  /**
   * The default {@link NioSocketChannelConfig} implementation.
   */
  class DefaultNioSocketChannelConfig extends DefaultSocketChannelConfig
          implements NioSocketChannelConfig {
  
      private static final InternalLogger logger =
          InternalLoggerFactory.getInstance(DefaultNioSocketChannelConfig.class);
  
      private static final ReceiveBufferSizePredictorFactory DEFAULT_PREDICTOR_FACTORY =
          new AdaptiveReceiveBufferSizePredictorFactory();
  
      private volatile int writeBufferHighWaterMark = 64 * 1024;
      private volatile int writeBufferLowWaterMark  = 32 * 1024;
      private volatile ReceiveBufferSizePredictor predictor;
      private volatile ReceiveBufferSizePredictorFactory predictorFactory = DEFAULT_PREDICTOR_FACTORY;
      private volatile int writeSpinCount = 16;
  
      DefaultNioSocketChannelConfig(Socket socket) {
          super(socket);
      }
  
      @Override
      public void setOptions(Map<String, Object> options) {
          super.setOptions(options);
          if (getWriteBufferHighWaterMark() < getWriteBufferLowWaterMark()) {
              // Recover the integrity of the configuration with a sensible value.
              setWriteBufferLowWaterMark0(getWriteBufferHighWaterMark() >>> 1);
              if (logger.isWarnEnabled()) {
                  // Notify the user about misconfiguration.
                  logger.warn(
                          "writeBufferLowWaterMark cannot be greater than " +
                          "writeBufferHighWaterMark; setting to the half of the " +
                          "writeBufferHighWaterMark.");
              }
  
          }
      }
  
      @Override
      public boolean setOption(String key, Object value) {
          if (super.setOption(key, value)) {
              return true;
          }
  
          if (key.equals("writeBufferHighWaterMark")) {
              setWriteBufferHighWaterMark0(ConversionUtil.toInt(value));
          } else if (key.equals("writeBufferLowWaterMark")) {
              setWriteBufferLowWaterMark0(ConversionUtil.toInt(value));
          } else if (key.equals("writeSpinCount")) {
              setWriteSpinCount(ConversionUtil.toInt(value));
          } else if (key.equals("receiveBufferSizePredictorFactory")) {
              setReceiveBufferSizePredictorFactory((ReceiveBufferSizePredictorFactory) value);
          } else if (key.equals("receiveBufferSizePredictor")) {
              setReceiveBufferSizePredictor((ReceiveBufferSizePredictor) value);
          } else {
              return false;
          }
          return true;
      }
  
      public int getWriteBufferHighWaterMark() {
          return writeBufferHighWaterMark;
      }
  
      public void setWriteBufferHighWaterMark(int writeBufferHighWaterMark) {
          if (writeBufferHighWaterMark < getWriteBufferLowWaterMark()) {
              throw new IllegalArgumentException(
                      "writeBufferHighWaterMark cannot be less than " +
                      "writeBufferLowWaterMark (" + getWriteBufferLowWaterMark() + "): " +
                     writeBufferHighWaterMark);
         }
         setWriteBufferHighWaterMark0(writeBufferHighWaterMark);
     }
 
     private void setWriteBufferHighWaterMark0(int writeBufferHighWaterMark) {
         if (writeBufferHighWaterMark < 0) {
             throw new IllegalArgumentException(
                     "writeBufferHighWaterMark: " + writeBufferHighWaterMark);
         }
         this.writeBufferHighWaterMark = writeBufferHighWaterMark;
     }
 
     public int getWriteBufferLowWaterMark() {
         return writeBufferLowWaterMark;
     }
 
     public void setWriteBufferLowWaterMark(int writeBufferLowWaterMark) {
         if (writeBufferLowWaterMark > getWriteBufferHighWaterMark()) {
             throw new IllegalArgumentException(
                     "writeBufferLowWaterMark cannot be greater than " +
                     "writeBufferHighWaterMark (" + getWriteBufferHighWaterMark() + "): " +
                     writeBufferLowWaterMark);
         }
         setWriteBufferLowWaterMark0(writeBufferLowWaterMark);
     }
 
     private void setWriteBufferLowWaterMark0(int writeBufferLowWaterMark) {
         if (writeBufferLowWaterMark < 0) {
             throw new IllegalArgumentException(
                     "writeBufferLowWaterMark: " + writeBufferLowWaterMark);
         }
         this.writeBufferLowWaterMark = writeBufferLowWaterMark;
     }
 
     public int getWriteSpinCount() {
         return writeSpinCount;
     }
 
     public void setWriteSpinCount(int writeSpinCount) {
         if (writeSpinCount <= 0) {
             throw new IllegalArgumentException(
                     "writeSpinCount must be a positive integer.");
         }
         this.writeSpinCount = writeSpinCount;
     }
 
     public ReceiveBufferSizePredictor getReceiveBufferSizePredictor() {
         ReceiveBufferSizePredictor predictor = this.predictor;
         if (predictor == null) {
             try {
                 this.predictor = predictor = getReceiveBufferSizePredictorFactory().getPredictor();
             } catch (Exception e) {
                 throw new ChannelException(
                         "Failed to create a new " +
                         ReceiveBufferSizePredictor.class.getSimpleName() + '.',
                         e);
             }
         }
         return predictor;
     }
 
     public void setReceiveBufferSizePredictor(
             ReceiveBufferSizePredictor predictor) {
         if (predictor == null) {
             throw new NullPointerException("predictor");
         }
         this.predictor = predictor;
     }
 
     public ReceiveBufferSizePredictorFactory getReceiveBufferSizePredictorFactory() {
         return predictorFactory;
     }
 
     public void setReceiveBufferSizePredictorFactory(ReceiveBufferSizePredictorFactory predictorFactory) {
         if (predictorFactory == null) {
             throw new NullPointerException("predictorFactory");
         }
         this.predictorFactory = predictorFactory;
     }
 }