/* Copyright (c) 2006, 2016, Oracle and/or its affiliates. All rights reserved.

   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; version 2 of the License.

   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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */

#ifndef SQL_CONNECT_INCLUDED
#define SQL_CONNECT_INCLUDED

#include "my_global.h"   // uint

class THD;
typedef struct st_lex_user LEX_USER;

/*
  This structure specifies the maximum amount of resources which
  can be consumed by each account. Zero value of a member means
  there is no limit.
*/
typedef struct user_resources {
  /* Maximum number of queries/statements per hour. */
  uint questions;
  /*
     Maximum number of updating statements per hour (which statements are
     updating is defined by sql_command_flags array).
  */
  uint updates;
  /* Maximum number of connections established per hour. */
  uint conn_per_hour;
  /* Maximum number of concurrent connections. */
  uint user_conn;
  /*
     Values of this enum and specified_limits member are used by the
     parser to store which user limits were specified in GRANT statement.
  */
  enum {QUERIES_PER_HOUR= 1, UPDATES_PER_HOUR= 2, CONNECTIONS_PER_HOUR= 4,
        USER_CONNECTIONS= 8};
  uint specified_limits;
} USER_RESOURCES;


/*
  This structure is used for counting resources consumed and for checking
  them against specified user limits.
*/
typedef struct user_conn {
  /*
     Pointer to user+host key (pair separated by '\0') defining the entity
     for which resources are counted (By default it is user account thus
     priv_user/priv_host pair is used. If --old-style-user-limits option
     is enabled, resources are counted for each user+host separately).
  */
  char *user;
  /* Pointer to host part of the key. */
  char *host;
  /**
     The moment of time when per hour counters were reset last time
     (i.e. start of "hour" for conn_per_hour, updates, questions counters).
  */
  ulonglong reset_utime;
  /* Total length of the key. */
  size_t len;
  /* Current amount of concurrent connections for this account. */
  uint connections;
  /*
     Current number of connections per hour, number of updating statements
     per hour and total number of statements per hour for this account.
  */
  uint conn_per_hour, updates, questions;
  /* Maximum amount of resources which account is allowed to consume. */
  USER_RESOURCES user_resources;
} USER_CONN;


void init_max_user_conn(void);
void free_max_user_conn(void);
void reset_mqh(LEX_USER *lu, bool get_them);
bool check_mqh(THD *thd, uint check_command);
void decrease_user_connections(USER_CONN *uc);
void release_user_connection(THD *thd);
bool thd_init_client_charset(THD *thd, uint cs_number);
bool thd_prepare_connection(THD *thd);
void close_connection(THD *thd, uint sql_errno= 0,
                      bool server_shutdown= false, bool generate_event= true);
bool thd_connection_alive(THD *thd);
void end_connection(THD *thd);
int get_or_create_user_conn(THD *thd, const char *user,
                            const char *host, const USER_RESOURCES *mqh);
int check_for_max_user_connections(THD *thd, const USER_CONN *uc);

#endif /* SQL_CONNECT_INCLUDED */