content: /*
   * Copyright 1999-2012 Alibaba Group.
   *  
   * Licensed 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.cobar.mysql.nio;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import com.alibaba.cobar.mysql.ByteUtil;
  import com.alibaba.cobar.mysql.nio.handler.ResponseHandler;
  import com.alibaba.cobar.net.handler.BackendAsyncHandler;
  import com.alibaba.cobar.net.mysql.EOFPacket;
  import com.alibaba.cobar.net.mysql.ErrorPacket;
  import com.alibaba.cobar.net.mysql.OkPacket;
  
  /**
   * life cycle: from connection establish to close <br/>
   * 
   * @author xianmao.hexm 2012-4-12
   */
  public class MySQLConnectionHandler extends BackendAsyncHandler {
      private static final int RESULT_STATUS_INIT = 0;
      private static final int RESULT_STATUS_HEADER = 1;
      private static final int RESULT_STATUS_FIELD_EOF = 2;
  
      private final MySQLConnection source;
      private volatile int resultStatus;
      private volatile byte[] header;
      private volatile List<byte[]> fields;
  
      /**
       * life cycle: one SQL execution
       */
      private volatile ResponseHandler responseHandler;
  
      public MySQLConnectionHandler(MySQLConnection source) {
          this.source = source;
          this.resultStatus = RESULT_STATUS_INIT;
      }
  
      public void connectionError(Throwable e) {
          // connError = e;
          // handleQueue();
      }
  
      public MySQLConnection getSource() {
          return source;
      }
  
      @Override
      public void handle(byte[] data) {
          offerData(data, source.getProcessor().getExecutor());
      }
  
      @Override
      protected void offerDataError() {
          dataQueue.clear();
          resultStatus = RESULT_STATUS_INIT;
          throw new RuntimeException("offer data error!");
      }
  
      @Override
      protected void handleData(byte[] data) {
          switch (resultStatus) {
          case RESULT_STATUS_INIT:
              switch (data[4]) {
              case OkPacket.FIELD_COUNT:
                  handleOkPacket(data);
                  break;
              case ErrorPacket.FIELD_COUNT:
                  handleErrorPacket(data);
                  break;
              default:
                  resultStatus = RESULT_STATUS_HEADER;
                  header = data;
                  fields = new ArrayList<byte[]>((int) ByteUtil.readLength(data, 4));
              }
              break;
          case RESULT_STATUS_HEADER:
              switch (data[4]) {
              case ErrorPacket.FIELD_COUNT:
                  resultStatus = RESULT_STATUS_INIT;
                  handleErrorPacket(data);
                  break;
              case EOFPacket.FIELD_COUNT:
                  resultStatus = RESULT_STATUS_FIELD_EOF;
                  handleFieldEofPacket(data);
                  break;
              default:
                  fields.add(data);
              }
              break;
          case RESULT_STATUS_FIELD_EOF:
              switch (data[4]) {
              case ErrorPacket.FIELD_COUNT:
                  resultStatus = RESULT_STATUS_INIT;
                  handleErrorPacket(data);
                  break;
              case EOFPacket.FIELD_COUNT:
                  resultStatus = RESULT_STATUS_INIT;
                  handleRowEofPacket(data);
                  break;
              default:
                  handleRowPacket(data);
              }
              break;
          default:
              throw new RuntimeException("unknown status!");
          }
      }
  
      public void setResponseHandler(ResponseHandler responseHandler) {
          this.responseHandler = responseHandler;
      }
  
      @Override
      protected void handleDataError(Throwable t) {
          dataQueue.clear();
          resultStatus = RESULT_STATUS_INIT;
          responseHandler.connectionError(t, source);
      }
  
      /**
       * OK数据包处理
       */
      private void handleOkPacket(byte[] data) {
          responseHandler.okResponse(data, source);
      }
  
      /**
       * ERROR数据包处理
       */
      private void handleErrorPacket(byte[] data) {
          responseHandler.errorResponse(data, source);
      }
  
      /**
       * 字段数据包结束处理
       */
      private void handleFieldEofPacket(byte[] data) {
          responseHandler.fieldEofResponse(header, fields, data, source);
      }
  
      /**
       * 行数据包处理
       */
      private void handleRowPacket(byte[] data) {
          responseHandler.rowResponse(data, source);
      }
  
      /**
       * 行数据包结束处理
       */
      private void handleRowEofPacket(byte[] data) {
          responseHandler.rowEofResponse(data, source);
      }
  
  }
  