content: /*
   * Copyright (C) 2016-2023 ActionTech.
   * based on code by MyCATCopyrightHolder Copyright (c) 2013, OpenCloudDB/MyCAT.
   * License: http://www.gnu.org/licenses/gpl.html GPL version 2 or higher.
   */
  package com.actiontech.dble.services.manager.response;
  
  import com.actiontech.dble.DbleServer;
  import com.actiontech.dble.backend.mysql.PacketUtil;
  
  import com.actiontech.dble.config.Fields;
  import com.actiontech.dble.net.IOProcessor;
  import com.actiontech.dble.net.connection.BackendConnection;
  import com.actiontech.dble.net.connection.PooledConnection;
  import com.actiontech.dble.net.mysql.*;
  import com.actiontech.dble.services.manager.ManagerService;
  import com.actiontech.dble.util.LongUtil;
  import com.actiontech.dble.util.StringUtil;
  
  import java.nio.ByteBuffer;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * ShowBackend
   *
   * @author mycat
   */
  public final class ShowBackendStat {
      private ShowBackendStat() {
      }
  
      private static final int FIELD_COUNT = 4;
      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("HOST", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("PORT", Fields.FIELD_TYPE_LONG);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("ACTIVE", Fields.FIELD_TYPE_LONGLONG);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("TOTAL", Fields.FIELD_TYPE_LONGLONG);
          FIELDS[i].setPacketId(++packetId);
  
          EOF.setPacketId(++packetId);
      }
  
      public static void execute(ManagerService service) {
          ByteBuffer buffer = service.allocate();
  
          buffer = HEADER.write(buffer, service, true);
  
          for (FieldPacket field : FIELDS) {
              buffer = field.write(buffer, service, true);
          }
  
          buffer = EOF.write(buffer, service, true);
  
          HashMap<String, BackendStat> infos = stat();
  
          byte packetId = EOF.getPacketId();
          for (Map.Entry<String, BackendStat> entry : infos.entrySet()) {
              RowDataPacket row = getRow(entry.getValue(), service.getCharset().getResults());
              row.setPacketId(++packetId);
              buffer = row.write(buffer, service, true);
          }
  
          EOFRowPacket lastEof = new EOFRowPacket();
          lastEof.setPacketId(++packetId);
  
          lastEof.write(buffer, service);
      }
  
      private static RowDataPacket getRow(BackendStat info, String charset) {
          RowDataPacket row = new RowDataPacket(FIELD_COUNT);
          row.add(StringUtil.encode(info.getHost(), charset));
          row.add(LongUtil.toBytes(info.getPort()));
          row.add(LongUtil.toBytes(info.getActive()));
          row.add(LongUtil.toBytes(info.getTotal()));
          return row;
      }
  
      private static HashMap<String, BackendStat> stat() {
          HashMap<String, BackendStat> all = new HashMap<>();
  
          for (IOProcessor p : DbleServer.getInstance().getBackendProcessors()) {
              for (BackendConnection bc : p.getBackends().values()) {
                  String host = bc.getHost();
                  long port = bc.getPort();
                  BackendStat info = all.get(host + port);
                  if (info == null) {
                      info = new BackendStat(host, port);
                      all.put(host + port, info);
                  }
  
                  if (bc.getState() == PooledConnection.STATE_IN_USE) {
                      info.addActive();
                  }
                  info.addTotal();
              }
          }
          return all;
      }
  
      private static class BackendStat {
          private String host;
          private long port;
          private long active;
          private long total;
  
          BackendStat(String host, long port) {
              this.host = host;
              this.port = port;
              this.active = 0;
              this.total = 0;
          }
  
          public String getHost() {
              return this.host;
          }
  
          public long getPort() {
              return this.port;
          }
  
          public void addActive() {
              this.active++;
          }
  
          public void addTotal() {
              this.total++;
          }
  
          public long getActive() {
              return this.active;
          }
  
          public long getTotal() {
              return this.total;
          }
      }
  }
  