Memcache Codec with Quit Support

gistfile1.scala

import com.twitter.finagle.{Codec, Service}
import com.twitter.finagle.memcached.protocol.{Command, Response, Quit => MemcacheQuit, NoOp}
import com.twitter.finagle.memcached.protocol.text.{Encoder, Memcached, ResponseToEncoding}
import com.twitter.finagle.memcached.protocol.text.server.{Decoder => ServerDecoder, DecodingToCommand}
import com.twitter.logging.Logger
import com.twitter.util.Future

import org.jboss.netty.buffer.{ChannelBuffer, ChannelBuffers}
import org.jboss.netty.channel._
import org.jboss.netty.util.CharsetUtil

// Simple ChannelHandler that deals with the protocol specified quit message
class MemcacheChannelHandler extends SimpleChannelHandler {
  override def messageReceived(ctx: ChannelHandlerContext, e: MessageEvent) {
    e.getMessage() match {     
      case MemcacheQuit() =>   
        ctx.getChannel().close()        
      case _ => super.messageReceived(ctx, e)
    }
  }
}

class MemcachedQuitCodec extends Memcached {
  implicit def str2cb(str: String): ChannelBuffer = ChannelBuffers.copiedBuffer(str, CharsetUtil.UTF_8)

  private[this] val storageCommands = collection.Set[ChannelBuffer](
    "set", "add", "replace", "append", "prepend") 

  override def server = Function.const {
    new Codec[Command, Response] {  
      def pipelineFactory = new ChannelPipelineFactory {
        def getPipeline() = {
          val pipeline = Channels.pipeline()

          pipeline.addLast("decoder", new ServerDecoder(storageCommands)) 
          pipeline.addLast("decoding2command", new DecodingToCommand)

          // NOTE This is the only change to the parent class
          pipeline.addLast("handleQuitCommand", new MemcacheChannelHandler)

          pipeline.addLast("encoder", new Encoder)
          pipeline.addLast("response2encoding", new ResponseToEncoding)
          pipeline
        }
      }
    } // new Codec
  } // server
} // class