content: /*
   * Copyright (c) 2002, 2020, 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.jdbc;
  
  import java.sql.SQLClientInfoException;
  import java.sql.SQLException;
  import java.util.Enumeration;
  import java.util.Properties;
  
  /**
   * An implementation of ClientInfoProvider that exposes the client info as a comment prepended to all statements issued by the driver.
   * 
   * Client information is <i>never</i> read from the server with this implementation, it is always cached locally.
   */
  
  public class CommentClientInfoProvider implements ClientInfoProvider {
      private Properties clientInfo;
  
      @Override
      public synchronized void initialize(java.sql.Connection conn, Properties configurationProps) throws SQLException {
          this.clientInfo = new Properties();
      }
  
      @Override
      public synchronized void destroy() throws SQLException {
          this.clientInfo = null;
      }
  
      @Override
      public synchronized Properties getClientInfo(java.sql.Connection conn) throws SQLException {
          return this.clientInfo;
      }
  
      @Override
      public synchronized String getClientInfo(java.sql.Connection conn, String name) throws SQLException {
          return this.clientInfo.getProperty(name);
      }
  
      @Override
      public synchronized void setClientInfo(java.sql.Connection conn, Properties properties) throws SQLClientInfoException {
          this.clientInfo = new Properties();
  
          Enumeration<?> propNames = properties.propertyNames();
  
          while (propNames.hasMoreElements()) {
              String name = (String) propNames.nextElement();
  
              this.clientInfo.put(name, properties.getProperty(name));
          }
  
          setComment(conn);
      }
  
      @Override
      public synchronized void setClientInfo(java.sql.Connection conn, String name, String value) throws SQLClientInfoException {
          this.clientInfo.setProperty(name, value);
          setComment(conn);
      }
  
      private synchronized void setComment(java.sql.Connection conn) {
          StringBuilder commentBuf = new StringBuilder();
  
          Enumeration<?> propNames = this.clientInfo.propertyNames();
  
          while (propNames.hasMoreElements()) {
              String name = (String) propNames.nextElement();
  
              if (commentBuf.length() > 0) {
                  commentBuf.append(", ");
              }
  
              commentBuf.append("" + name);
              commentBuf.append("=");
              commentBuf.append("" + this.clientInfo.getProperty(name));
          }
  
          ((com.mysql.cj.jdbc.JdbcConnection) conn).setStatementComment(commentBuf.toString());
      }
  }
  