content: /*
   * Copyright (c) 2021, Oracle and/or its affiliates.
   *
   * This program is free software; you can redistribute it and/or modify it under
   * the terms of the GNU General Public License, version 2.0, as published by the
   * Free Software Foundation.
   *
   * This program is also distributed with certain software (including but not
   * limited to OpenSSL) that is licensed under separate terms, as designated in a
   * particular file or component or in included license documentation. The
   * authors of MySQL hereby grant you an additional permission to link the
   * program and your derivative works with the separately licensed software that
   * they have included with MySQL.
   *
   * Without limiting anything contained in the foregoing, this file, which is
   * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
   * version 1.0, a copy of which can be found at
   * http://oss.oracle.com/licenses/universal-foss-exception.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   * FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
   * for more details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
   */
  
  package com.mysql.cj.protocol.a;
  
  import java.lang.ref.WeakReference;
  import java.util.ArrayList;
  import java.util.List;
  
  import com.mysql.cj.protocol.ServerSessionStateController;
  import com.mysql.cj.protocol.a.NativeConstants.IntegerDataType;
  import com.mysql.cj.protocol.a.NativeConstants.StringLengthDataType;
  import com.mysql.cj.protocol.a.NativeConstants.StringSelfDataType;
  
  public class NativeServerSessionStateController implements ServerSessionStateController {
      private NativeServerSessionStateChanges sessionStateChanges;
      private List<WeakReference<SessionStateChangesListener>> listeners;
  
      @Override
      public void setSessionStateChanges(ServerSessionStateChanges changes) {
          this.sessionStateChanges = (NativeServerSessionStateChanges) changes;
          if (this.listeners != null) {
              for (WeakReference<SessionStateChangesListener> wr : this.listeners) {
                  SessionStateChangesListener l = wr.get();
                  if (l != null) {
                      l.handleSessionStateChanges(changes);
                  } else {
                      this.listeners.remove(wr);
                  }
              }
          }
      }
  
      @Override
      public NativeServerSessionStateChanges getSessionStateChanges() {
          return this.sessionStateChanges;
      }
  
      @Override
      public void addSessionStateChangesListener(SessionStateChangesListener l) {
          if (this.listeners == null) {
              this.listeners = new ArrayList<>();
          }
          for (WeakReference<SessionStateChangesListener> wr : this.listeners) {
              if (l.equals(wr.get())) {
                  return;
              }
          }
          this.listeners.add(new WeakReference<>(l));
      }
  
      @Override
      public void removeSessionStateChangesListener(SessionStateChangesListener listener) {
          if (this.listeners != null) {
              for (WeakReference<SessionStateChangesListener> wr : this.listeners) {
                  SessionStateChangesListener l = wr.get();
                  if (l == null || l.equals(listener)) {
                      this.listeners.remove(wr);
                      break;
                  }
              }
          }
      }
  
      public static class NativeServerSessionStateChanges implements ServerSessionStateChanges {
          private List<SessionStateChange> sessionStateChanges = new ArrayList<>();
  
          @Override
          public List<SessionStateChange> getSessionStateChangesList() {
              return this.sessionStateChanges;
          }
  
          public NativeServerSessionStateChanges() {
          }
  
          public NativeServerSessionStateChanges init(NativePacketPayload buf, String encoding) {
              int totalLen = (int) buf.readInteger(IntegerDataType.INT_LENENC);
              int start = buf.getPosition();
              int end = start + totalLen;
              while (totalLen > 0 && end > start) {
                  int type = (int) buf.readInteger(IntegerDataType.INT1);
                  NativePacketPayload b = new NativePacketPayload(buf.readBytes(StringSelfDataType.STRING_LENENC));
                  switch (type) {
                      case SESSION_TRACK_SYSTEM_VARIABLES:
                          this.sessionStateChanges.add(new SessionStateChange(type) //
                                  .addValue(b.readString(StringSelfDataType.STRING_LENENC, encoding)) //
                                  .addValue(b.readString(StringSelfDataType.STRING_LENENC, encoding)));
                          break;
                      case SESSION_TRACK_SCHEMA:
                      case SESSION_TRACK_TRANSACTION_CHARACTERISTICS:
                      case SESSION_TRACK_TRANSACTION_STATE:
                          this.sessionStateChanges.add(new SessionStateChange(type) //
                                  .addValue(b.readString(StringSelfDataType.STRING_LENENC, encoding)));
                          break;
                      case SESSION_TRACK_GTIDS:
                          b.readInteger(IntegerDataType.INT1); // skip the byte reserved for the encoding specification, see WL#6128
                          this.sessionStateChanges.add(new SessionStateChange(type) //
                                  .addValue(b.readString(StringSelfDataType.STRING_LENENC, encoding)));
                          break;
                      case SESSION_TRACK_STATE_CHANGE:
                      default:
                          // store the payload as it is
                          this.sessionStateChanges.add(new SessionStateChange(type) //
                                  .addValue(b.readString(StringLengthDataType.STRING_FIXED, encoding, b.getPayloadLength())));
                  }
                  start = buf.getPosition();
              }
              return this;
          }
  
      }
  }
  