content: /*
   * Copyright (C) 2016-2023 ActionTech.
   * License: http://www.gnu.org/licenses/gpl.html GPL version 2 or higher.
   */
  
  package com.actiontech.dble.services.manager.response;
  
  import com.actiontech.dble.backend.mysql.PacketUtil;
  import com.actiontech.dble.config.Fields;
  import com.actiontech.dble.config.model.ParamInfo;
  import com.actiontech.dble.net.mysql.*;
  import com.actiontech.dble.services.manager.ManagerService;
  import com.actiontech.dble.singleton.SystemParams;
  import com.actiontech.dble.util.StringUtil;
  
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * show Sysconfig param detail info
   *
   * @author rainbow
   */
  public final class ShowSysParam {
      private ShowSysParam() {
      }
  
      private static final int FIELD_COUNT = 3;
      private static final ResultSetHeaderPacket HEADER = PacketUtil.getHeader(FIELD_COUNT);
      private static final FieldPacket[] FIELDS = new FieldPacket[FIELD_COUNT];
      private static final EOFPacket EOF = new EOFPacket();
  
      static {
          int i = 0;
          byte packetId = 0;
          HEADER.setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("PARAM_NAME", Fields.FIELD_TYPE_VARCHAR);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("PARAM_VALUE", Fields.FIELD_TYPE_VARCHAR);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("PARAM_DESCR", Fields.FIELD_TYPE_VARCHAR);
          FIELDS[i].setPacketId(++packetId);
  
          EOF.setPacketId(++packetId);
      }
  
      public static void execute(ManagerService service) {
          ByteBuffer buffer = service.allocate();
  
          // write header
          buffer = HEADER.write(buffer, service, true);
  
          // write fields
          for (FieldPacket field : FIELDS) {
              buffer = field.write(buffer, service, true);
          }
  
          // write eof
          buffer = EOF.write(buffer, service, true);
  
          // write rows
          byte packetId = EOF.getPacketId();
          List<ParamInfo> params = new ArrayList<>();
          params.addAll(SystemParams.getInstance().getReadOnlyParams());
          params.addAll(SystemParams.getInstance().getVolatileParams());
          for (ParamInfo info : params) {
              RowDataPacket row = new RowDataPacket(FIELD_COUNT);
              row.add(StringUtil.encode(info.getName(), service.getCharset().getResults()));
              row.add(StringUtil.encode(info.getValue(), service.getCharset().getResults()));
              row.add(StringUtil.encode(info.getComment(), service.getCharset().getResults()));
              row.setPacketId(++packetId);
              buffer = row.write(buffer, service, true);
          }
  
          // write last eof
          EOFRowPacket lastEof = new EOFRowPacket();
          lastEof.setPacketId(++packetId);
  
  
          lastEof.write(buffer, service);
      }
  }
  