text: /*
   * Copyright (c) 2018 MariaDB Corporation Ab
   *
   * Use of this software is governed by the Business Source License included
   * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
   *
   * Change Date: 2023-01-01
   *
   * On the date above, in accordance with the Business Source License, use
   * of this software will be governed by version 2 or later of the General
   * Public License.
   */
  #pragma once
  
  #include <maxscale/ccdefs.hh>
  #include <maxscale/dcb.hh>
  #include <maxscale/modinfo.h>
  #include <maxscale/resultset.hh>
  
  /* Module types */
  #define MODULE_PROTOCOL         "Protocol"          /**< A protocol module type */
  #define MODULE_AUTHENTICATOR    "Authenticator"     /**< An authenticator module type */
  #define MODULE_ROUTER           "Router"            /**< A router module type */
  #define MODULE_MONITOR          "Monitor"           /**< A database monitor module type */
  #define MODULE_FILTER           "Filter"            /**< A filter module type */
  #define MODULE_QUERY_CLASSIFIER "QueryClassifier"   /**< A query classifier module type */
  
  /**
   * @brief Return a resultset that has the current set of modules in it
   *
   * @return A Result set
   */
  std::unique_ptr<ResultSet> moduleGetList();
  
  MXS_BEGIN_DECLS
  
  /**
   *@brief Load a module
   *
   * @param module Name of the module to load
   * @param type   Type of module, used purely for registration
   * @return       The module specific entry point structure or NULL
   */
  void* load_module(const char* module, const char* type);
  
  /**
   * @brief Get a module
   *
   * @param name Name of the module
   * @param type The module type or NULL for any type
   * @return The loaded module or NULL if the module is not loaded
   */
  const MXS_MODULE* get_module(const char* name, const char* type);
  
  /**
   * @brief Unload a module.
   *
   * No errors are returned since it is not clear that much can be done
   * to fix issues relating to unloading modules.
   *
   * @param module The name of the module
   */
  void unload_module(const char* module);
  
  /**
   * @brief Unload all modules
   *
   * Remove all the modules from the system, called during shutdown
   * to allow termination hooks to be called.
   */
  void unload_all_modules();
  
  /**
   * @brief Print Modules
   *
   * Diagnostic routine to display all the loaded modules
   */
  void printModules();
  
  /**
   * @brief Print Modules to a DCB
   *
   * Diagnostic routine to display all the loaded modules
   */
  void dprintAllModules(DCB*);
  
  typedef struct mxs_module_iterator
  {
      const char* type;
      void*       position;
  } MXS_MODULE_ITERATOR;
  
  /**
   * @brief Returns an iterator to modules.
   *
   * @attention It is unspecified whether a module loaded after the iterator
   *            was created, will be returned by the iterator. The behaviour
   *            is undefined if a module is unloaded while an iteration is
   *            being performed.
   *
   * @param type  The type of modules that should be returned. If NULL,
   *              then all modules are returned.
   *
   * @return An iterator.
   */
  MXS_MODULE_ITERATOR mxs_module_iterator_get(const char* type);
  
  /**
   * @brief Indicates whether the iterator has a module to return.
   *
   * @param iterator  An iterator
   *
   * @return True if a subsequent call to @c mxs_module_iterator_get
   *         will return a module.
   */
  bool mxs_module_iterator_has_next(const MXS_MODULE_ITERATOR* iterator);
  
  /**
   * @brief Returns the next module and advances the iterator.
   *
   * @param iterator  An iterator.
   *
   * @return A module if there was a module to return, NULL otherwise.
   */
  MXS_MODULE* mxs_module_iterator_get_next(MXS_MODULE_ITERATOR* iterator);
  
  /**
   * @brief Convert module to JSON
   *
   * @param module Module to convert
   * @param host   Hostname of this server
   *
   * @return The module in JSON format
   */
  json_t* module_to_json(const MXS_MODULE* module, const char* host);
  
  /**
   * @brief Convert all modules to JSON
   *
   * @param host The hostname of this server
   *
   * @return Array of modules in JSON format
   */
  json_t* module_list_to_json(const char* host);
  
  /**
   * @brief Return effective module name.
   *
   * The effective module name is the actual name of a module. In case
   * a module has been renamed (and the old name deprecated), the effective
   * name of a module may be different from the used one.
   *
   * @param name  The name of a module.
   *
   * @return The effective name (may be the same).
   */
  const char* mxs_module_get_effective_name(const char* name);
  
  MXS_END_DECLS
  