set_var.h

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#ifndef SET_VAR_INCLUDED
#define SET_VAR_INCLUDED
/* Copyright (c) 2002, 2013 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 */

#include <my_getopt.h>
#include <vector>

class sys_var;
class set_var;
class sys_var_pluginvar;
class PolyLock;
class Item_func_set_user_var;

// This include needs to be here since item.h requires enum_var_type :-P
#include "item.h"                          /* Item */
#include "sql_class.h"                     /* THD  */

extern TYPELIB bool_typelib;

struct sys_var_chain
{
  sys_var *first;
  sys_var *last;
};

int mysql_add_sys_var_chain(sys_var *chain);
int mysql_del_sys_var_chain(sys_var *chain);

class sys_var
{
public:
  sys_var *next;
  LEX_CSTRING name;
  enum flag_enum { GLOBAL, SESSION, ONLY_SESSION, SCOPE_MASK=1023,
                   READONLY=1024, ALLOCATED=2048, INVISIBLE=4096 };
  static const int PARSE_EARLY= 1;
  static const int PARSE_NORMAL= 2;
  enum binlog_status_enum { VARIABLE_NOT_IN_BINLOG,
                            SESSION_VARIABLE_IN_BINLOG } binlog_status;

protected:
  typedef bool (*on_check_function)(sys_var *self, THD *thd, set_var *var);
  typedef bool (*on_update_function)(sys_var *self, THD *thd, enum_var_type type);

  int flags;            
  int m_parse_flag;     
  const SHOW_TYPE show_val_type; 
  my_option option;     
  PolyLock *guard;      
  ptrdiff_t offset;     
  on_check_function on_check;
  on_update_function on_update;
  const char *const deprecation_substitute;
  bool is_os_charset; 

public:
  sys_var(sys_var_chain *chain, const char *name_arg, const char *comment,
          int flag_args, ptrdiff_t off, int getopt_id,
          enum get_opt_arg_type getopt_arg_type, SHOW_TYPE show_val_type_arg,
          longlong def_val, PolyLock *lock, enum binlog_status_enum binlog_status_arg,
          on_check_function on_check_func, on_update_function on_update_func,
          const char *substitute, int parse_flag);

  virtual ~sys_var() {}

  virtual void cleanup() {}
  virtual sys_var_pluginvar *cast_pluginvar() { return 0; }

  bool check(THD *thd, set_var *var);
  uchar *value_ptr(THD *thd, enum_var_type type, LEX_STRING *base);
  virtual void update_default(longlong new_def_value)
  { option.def_value= new_def_value; }

  bool set_default(THD *thd, set_var *var);
  bool update(THD *thd, set_var *var);

  SHOW_TYPE show_type() { return show_val_type; }
  int scope() const { return flags & SCOPE_MASK; }
  const CHARSET_INFO *charset(THD *thd);
  bool is_readonly() const { return flags & READONLY; }
  bool not_visible() const { return flags & INVISIBLE; }
  bool is_struct() { return option.var_type & GET_ASK_ADDR; }
  bool is_written_to_binlog(enum_var_type type)
  { return type != OPT_GLOBAL && binlog_status == SESSION_VARIABLE_IN_BINLOG; }
  virtual bool check_update_type(Item_result type) = 0;
  bool check_type(enum_var_type type)
  {
    switch (scope())
    {
    case GLOBAL:       return type != OPT_GLOBAL;
    case SESSION:      return false; // always ok
    case ONLY_SESSION: return type == OPT_GLOBAL;
    }
    return true; // keep gcc happy
  }
  bool register_option(std::vector<my_option> *array, int parse_flags)
  {
    return (option.id != -1) && (m_parse_flag & parse_flags) &&
      (array->push_back(option), false);
  }
  void do_deprecated_warning(THD *thd);

private:
  virtual bool do_check(THD *thd, set_var *var) = 0;
  virtual void session_save_default(THD *thd, set_var *var) = 0;
  virtual void global_save_default(THD *thd, set_var *var) = 0;
  virtual bool session_update(THD *thd, set_var *var) = 0;
  virtual bool global_update(THD *thd, set_var *var) = 0;
protected:
  virtual uchar *session_value_ptr(THD *thd, LEX_STRING *base);
  virtual uchar *global_value_ptr(THD *thd, LEX_STRING *base);

  uchar *session_var_ptr(THD *thd)
  { return ((uchar*)&(thd->variables)) + offset; }

  uchar *global_var_ptr()
  { return ((uchar*)&global_system_variables) + offset; }
};

#include "binlog.h"                           /* binlog_format_typelib */
#include "sql_plugin.h"                    /* SHOW_HA_ROWS, SHOW_MY_BOOL */

/****************************************************************************
  Classes for parsing of the SET command
****************************************************************************/

class set_var_base :public Sql_alloc
{
public:
  set_var_base() {}
  virtual ~set_var_base() {}
  virtual int check(THD *thd)=0;           /* To check privileges etc. */
  virtual int update(THD *thd)=0;                  /* To set the value */
  virtual int light_check(THD *thd) { return check(thd); }   /* for PS */
  virtual void print(THD *thd, String *str)=0;  /* To self-print */
  virtual bool is_var_optimizer_trace() const { return false; }
};


class set_var :public set_var_base
{
public:
  sys_var *var; 
  Item *value;  
  enum_var_type type;
  union 
  {
    ulonglong ulonglong_value;          
    double double_value;                
    plugin_ref plugin;                  
    Time_zone *time_zone;               
    LEX_STRING string_value;            
    const void *ptr;                    
  } save_result;
  LEX_STRING base; 
  set_var(enum_var_type type_arg, sys_var *var_arg,
          const LEX_STRING *base_name_arg, Item *value_arg)
    :var(var_arg), type(type_arg), base(*base_name_arg)
  {
    /*
      If the set value is a field, change it to a string to allow things like
      SET table_type=MYISAM;
    */
    if (value_arg && value_arg->type() == Item::FIELD_ITEM)
    {
      Item_field *item= (Item_field*) value_arg;
      if (item->field_name)
      {
        if (!(value= new Item_string(item->field_name,
                                     (uint) strlen(item->field_name),
                                     system_charset_info))) // names are utf8
          value= value_arg;                     /* Give error message later */
      }
      else
      {
        /* Both Item_field and Item_insert_value will return the type as
        Item::FIELD_ITEM. If the item->field_name is NULL, we assume the
        object to be Item_insert_value. */
        value= value_arg;
      }
    }
    else
      value= value_arg;
  }
  int check(THD *thd);
  int update(THD *thd);
  int light_check(THD *thd);
  void print(THD *thd, String *str);    /* To self-print */
#ifdef OPTIMIZER_TRACE
  virtual bool is_var_optimizer_trace() const
  {
    extern sys_var *Sys_optimizer_trace_ptr;
    return var == Sys_optimizer_trace_ptr;
  }
#endif
};


/* User variables like @my_own_variable */
class set_var_user: public set_var_base
{
  Item_func_set_user_var *user_var_item;
public:
  set_var_user(Item_func_set_user_var *item)
    :user_var_item(item)
  {}
  int check(THD *thd);
  int update(THD *thd);
  int light_check(THD *thd);
  void print(THD *thd, String *str);    /* To self-print */
};

/* For SET PASSWORD */

class set_var_password: public set_var_base
{
  LEX_USER *user;
  char *password;
public:
  set_var_password(LEX_USER *user_arg,char *password_arg)
    :user(user_arg), password(password_arg)
  {}
  int check(THD *thd);
  int update(THD *thd);
  void print(THD *thd, String *str);    /* To self-print */
};


/* For SET NAMES and SET CHARACTER SET */

class set_var_collation_client: public set_var_base
{
  int   set_cs_flags;
  const CHARSET_INFO *character_set_client;
  const CHARSET_INFO *character_set_results;
  const CHARSET_INFO *collation_connection;
public:
  enum  set_cs_flags_enum { SET_CS_NAMES=1, SET_CS_DEFAULT=2, SET_CS_COLLATE=4 };
  set_var_collation_client(int set_cs_flags_arg,
                           const CHARSET_INFO *client_coll_arg,
                           const CHARSET_INFO *connection_coll_arg,
                           const CHARSET_INFO *result_coll_arg)
    :set_cs_flags(set_cs_flags_arg),
     character_set_client(client_coll_arg),
     character_set_results(result_coll_arg),
     collation_connection(connection_coll_arg)
  {}
  int check(THD *thd);
  int update(THD *thd);
  void print(THD *thd, String *str);    /* To self-print */
};


/* optional things, have_* variables */
extern SHOW_COMP_OPTION have_csv;
extern SHOW_COMP_OPTION have_ndbcluster, have_partitioning;
extern SHOW_COMP_OPTION have_profiling;

extern SHOW_COMP_OPTION have_ssl, have_symlink, have_dlopen;
extern SHOW_COMP_OPTION have_query_cache;
extern SHOW_COMP_OPTION have_geometry, have_rtree_keys;
extern SHOW_COMP_OPTION have_crypt;
extern SHOW_COMP_OPTION have_compress;

/*
  Prototypes for helper functions
*/

SHOW_VAR* enumerate_sys_vars(THD *thd, bool sorted, enum enum_var_type type);

sys_var *find_sys_var(THD *thd, const char *str, uint length=0);
int sql_set_variables(THD *thd, List<set_var_base> *var_list);

bool fix_delay_key_write(sys_var *self, THD *thd, enum_var_type type);

sql_mode_t expand_sql_mode(sql_mode_t sql_mode);
bool sql_mode_string_representation(THD *thd, sql_mode_t sql_mode, LEX_STRING *ls);

extern sys_var *Sys_autocommit_ptr;
extern sys_var *Sys_gtid_next_ptr;
extern sys_var *Sys_gtid_next_list_ptr;
extern sys_var *Sys_gtid_purged_ptr;

const CHARSET_INFO *get_old_charset_by_name(const char *old_name);

int sys_var_init();
int sys_var_add_options(std::vector<my_option> *long_options, int parse_flags);
void sys_var_end(void);

#endif