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.net.mysql;
  
  import java.nio.ByteBuffer;
  
  import com.alibaba.cobar.mysql.BufferUtil;
  import com.alibaba.cobar.mysql.MySQLMessage;
  import com.alibaba.cobar.net.FrontendConnection;
  
  /**
   * From server to client in response to command, if error.
   * 
   * <pre>
   * Bytes                       Name
   * -----                       ----
   * 1                           field_count, always = 0xff
   * 2                           errno
   * 1                           (sqlstate marker), always '#'
   * 5                           sqlstate (5 characters)
   * n                           message
   * 
   * @see http://forge.mysql.com/wiki/MySQL_Internals_ClientServer_Protocol#Error_Packet
   * </pre>
   * 
   * @author xianmao.hexm 2010-7-16 上午10:45:01
   */
  public class ErrorPacket extends MySQLPacket {
      public static final byte FIELD_COUNT = (byte) 0xff;
      private static final byte SQLSTATE_MARKER = (byte) '#';
      private static final byte[] DEFAULT_SQLSTATE = "HY000".getBytes();
  
      public byte fieldCount = FIELD_COUNT;
      public int errno;
      public byte mark = SQLSTATE_MARKER;
      public byte[] sqlState = DEFAULT_SQLSTATE;
      public byte[] message;
  
      public void read(BinaryPacket bin) {
          packetLength = bin.packetLength;
          packetId = bin.packetId;
          MySQLMessage mm = new MySQLMessage(bin.data);
          fieldCount = mm.read();
          errno = mm.readUB2();
          if (mm.hasRemaining() && (mm.read(mm.position()) == SQLSTATE_MARKER)) {
              mm.read();
              sqlState = mm.readBytes(5);
          }
          message = mm.readBytes();
      }
  
      public void read(byte[] data) {
          MySQLMessage mm = new MySQLMessage(data);
          packetLength = mm.readUB3();
          packetId = mm.read();
          fieldCount = mm.read();
          errno = mm.readUB2();
          if (mm.hasRemaining() && (mm.read(mm.position()) == SQLSTATE_MARKER)) {
              mm.read();
              sqlState = mm.readBytes(5);
          }
          message = mm.readBytes();
      }
  
      @Override
      public ByteBuffer write(ByteBuffer buffer, FrontendConnection c) {
          int size = calcPacketSize();
          buffer = c.checkWriteBuffer(buffer, c.getPacketHeaderSize() + size);
          BufferUtil.writeUB3(buffer, size);
          buffer.put(packetId);
          buffer.put(fieldCount);
          BufferUtil.writeUB2(buffer, errno);
          buffer.put(mark);
          buffer.put(sqlState);
          if (message != null) {
              buffer = c.writeToBuffer(message, buffer);
          }
          return buffer;
      }
  
      public void write(FrontendConnection c) {
          ByteBuffer buffer = c.allocate();
          BufferUtil.writeUB3(buffer, calcPacketSize());
          buffer.put(packetId);
          buffer.put(fieldCount);
          BufferUtil.writeUB2(buffer, errno);
          buffer.put(mark);
          buffer.put(sqlState);
          if (message != null) {
              buffer = c.writeToBuffer(message, buffer);
          }
          c.write(buffer);
      }
  
      @Override
      public int calcPacketSize() {
          int size = 9;// 1 + 2 + 1 + 5
          if (message != null) {
              size += message.length;
          }
          return size;
      }
  
      @Override
      protected String getPacketInfo() {
          return "MySQL Error Packet";
      }
  
  }
  