#ifndef INCLUDES_MYSQL_INSTANCE_MANAGER_INSTANCE_MAP_H
#define INCLUDES_MYSQL_INSTANCE_MANAGER_INSTANCE_MAP_H
/* Copyright (C) 2004 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   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 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include <my_global.h>
#include <my_sys.h>
#include <m_string.h>
#include <hash.h>

#if defined(__GNUC__) && defined(USE_PRAGMA_INTERFACE)
#pragma interface
#endif

class Guardian_thread;
class Instance;
class Named_value_arr;
class Thread_registry;

extern int load_all_groups(char ***groups, const char *filename);
extern void free_groups(char **groups);

extern int create_instance_in_file(const LEX_STRING *instance_name,
                                   const Named_value_arr *options);


/*
  Instance_map - stores all existing instances
*/

class Instance_map
{
public:
  /* Instance_map iterator */
  class Iterator
  {
  private:
    uint current_instance;
    Instance_map *instance_map;
  public:
    Iterator(Instance_map *instance_map_arg) :
     current_instance(0), instance_map(instance_map_arg)
    {}

    void go_to_first();
    Instance *next();
  };
  friend class Iterator;
public:
  /*
    Return a pointer to the instance or NULL, if there is no such instance.
    MT-NOTE: must be called under acquired lock.
  */
  Instance *find(const LEX_STRING *name);

  /* Clear the configuration cache and reload the configuration file. */
  int flush_instances();

  /* The operation is used to check if there is an active instance or not. */
  bool is_there_active_instance();

  void lock();
  void unlock();

  int init();

  /*
    Process a given option and assign it to appropricate instance. This is
    required for the option handler, passed to my_search_option_files().
  */
  int process_one_option(const LEX_STRING *group, const char *option);

  /*
    Add an instance into the internal hash.

    MT-NOTE: the operation must be called under acquired lock.
  */
  int add_instance(Instance *instance);

  /*
    Remove instance from the internal hash.

    MT-NOTE: the operation must be called under acquired lock.
  */
  int remove_instance(Instance *instance);

  /*
    Create a new instance and register it in the internal hash.

    MT-NOTE: the operation must be called under acquired lock.
  */
  int create_instance(const LEX_STRING *instance_name,
                      const Named_value_arr *options);

  Instance_map(const char *default_mysqld_path_arg,
               Thread_registry &thread_registry_arg);
  ~Instance_map();

  /*
    Retrieve client state name of the given instance.

    MT-NOTE: the options must be called under acquired locks of the following
    objects:
      - Instance_map;
      - Guardian_thread;
  */
  const char *get_instance_state_name(Instance *instance);

public:
  const char *mysqld_path;
  Guardian_thread *guardian;

private:
  /* loads options from config files */
  int load();
  /* inits instances argv's after all options have been loaded */
  bool complete_initialization();
private:
  enum { START_HASH_SIZE = 16 };
  pthread_mutex_t LOCK_instance_map;
  HASH hash;

  Thread_registry &thread_registry;
};

#endif /* INCLUDES_MYSQL_INSTANCE_MANAGER_INSTANCE_MAP_H */