path: root/sql/sql_base.h

/* Copyright 2006-2008 MySQL AB, 2008-2009 Sun Microsystems, Inc.

   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_BASE_INCLUDED
#define SQL_BASE_INCLUDED

#include "unireg.h"                    // REQUIRED: for other includes
#include "table.h"                              /* open_table_mode */
#include "sql_trigger.h"                        /* trg_event_type */
#include "sql_class.h"                          /* enum_mark_columns */
#include "mysqld.h"                             /* key_map */

class Item_ident;
struct Name_resolution_context;
class Open_table_context;
class Open_tables_state;
class Prelocking_strategy;
struct TABLE_LIST;
class THD;
struct handlerton;
struct TABLE;

typedef class st_select_lex SELECT_LEX;

typedef struct st_lock_param_type ALTER_PARTITION_PARAM_TYPE;

/*
  This enumeration type is used only by the function find_item_in_list
  to return the info on how an item has been resolved against a list
  of possibly aliased items.
  The item can be resolved:
   - against an alias name of the list's element (RESOLVED_AGAINST_ALIAS)
   - against non-aliased field name of the list  (RESOLVED_WITH_NO_ALIAS)
   - against an aliased field name of the list   (RESOLVED_BEHIND_ALIAS)
   - ignoring the alias name in cases when SQL requires to ignore aliases
     (e.g. when the resolved field reference contains a table name or
     when the resolved item is an expression)   (RESOLVED_IGNORING_ALIAS)
*/
enum enum_resolution_type {
  NOT_RESOLVED=0,
  RESOLVED_IGNORING_ALIAS,
  RESOLVED_BEHIND_ALIAS,
  RESOLVED_WITH_NO_ALIAS,
  RESOLVED_AGAINST_ALIAS
};

enum find_item_error_report_type {REPORT_ALL_ERRORS, REPORT_EXCEPT_NOT_FOUND,
				  IGNORE_ERRORS, REPORT_EXCEPT_NON_UNIQUE,
                                  IGNORE_EXCEPT_NON_UNIQUE};

enum enum_tdc_remove_table_type {TDC_RT_REMOVE_ALL, TDC_RT_REMOVE_NOT_OWN,
                                 TDC_RT_REMOVE_UNUSED};

/* bits for last argument to remove_table_from_cache() */
#define RTFC_NO_FLAG                0x0000
#define RTFC_OWNED_BY_THD_FLAG      0x0001
#define RTFC_WAIT_OTHER_THREAD_FLAG 0x0002
#define RTFC_CHECK_KILLED_FLAG      0x0004

bool check_dup(const char *db, const char *name, TABLE_LIST *tables);
bool table_cache_init(void);
void table_cache_free(void);
bool table_def_init(void);
void table_def_free(void);
void table_def_start_shutdown(void);
void assign_new_table_id(TABLE_SHARE *share);
uint cached_open_tables(void);
uint cached_table_definitions(void);
uint create_table_def_key(THD *thd, char *key, TABLE_LIST *table_list,
                          bool tmp_table);
TABLE_SHARE *get_table_share(THD *thd, TABLE_LIST *table_list, char *key,
                             uint key_length, uint db_flags, int *error,
                             my_hash_value_type hash_value);
void release_table_share(TABLE_SHARE *share);
TABLE_SHARE *get_cached_table_share(const char *db, const char *table_name);

TABLE *open_ltable(THD *thd, TABLE_LIST *table_list, thr_lock_type update,
                   uint lock_flags);
bool open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
                Open_table_context *ot_ctx);
bool name_lock_locked_table(THD *thd, TABLE_LIST *tables);
bool reopen_name_locked_table(THD* thd, TABLE_LIST* table_list, bool link_in);
TABLE *table_cache_insert_placeholder(THD *thd, const char *key,
                                      uint key_length);
bool lock_table_name_if_not_cached(THD *thd, const char *db,
                                   const char *table_name, TABLE **table);
void detach_merge_children(TABLE *table, bool clear_refs);
bool fix_merge_after_open(TABLE_LIST *old_child_list, TABLE_LIST **old_last,
                          TABLE_LIST *new_child_list, TABLE_LIST **new_last);
bool reopen_table(TABLE *table);
bool reopen_tables(THD *thd,bool get_locks,bool in_refresh);
void close_data_files_and_morph_locks(THD *thd, const char *db,
                                      const char *table_name);
bool open_new_frm(THD *thd, TABLE_SHARE *share, const char *alias,
                  uint db_stat, uint prgflag,
                  uint ha_open_flags, TABLE *outparam, TABLE_LIST *table_desc,
                  MEM_ROOT *mem_root);

bool get_key_map_from_key_list(key_map *map, TABLE *table,
                               List<String> *index_list);
TABLE *open_temporary_table(THD *thd, const char *path, const char *db,
			    const char *table_name, bool link_in_list);
TABLE *find_locked_table(TABLE *list, const char *db, const char *table_name);
TABLE *find_write_locked_table(TABLE *list, const char *db,
                               const char *table_name);
thr_lock_type read_lock_type_for_table(THD *thd,
                                       Query_tables_list *prelocking_ctx,
                                       TABLE_LIST *table_list);

my_bool mysql_rm_tmp_tables(void);
bool rm_temporary_table(handlerton *base, char *path);
void close_tables_for_reopen(THD *thd, TABLE_LIST **tables,
                             MDL_ticket *start_of_statement_svp);
TABLE_LIST *find_table_in_list(TABLE_LIST *table,
                               TABLE_LIST *TABLE_LIST::*link,
                               const char *db_name,
                               const char *table_name);
TABLE *find_temporary_table(THD *thd, const char *db, const char *table_name);
TABLE *find_temporary_table(THD *thd, TABLE_LIST *table_list);
void close_thread_tables(THD *thd);
bool fill_record_n_invoke_before_triggers(THD *thd, List<Item> &fields,
                                          List<Item> &values,
                                          bool ignore_errors,
                                          Table_triggers_list *triggers,
                                          enum trg_event_type event);
bool fill_record_n_invoke_before_triggers(THD *thd, Field **field,
                                          List<Item> &values,
                                          bool ignore_errors,
                                          Table_triggers_list *triggers,
                                          enum trg_event_type event);
bool insert_fields(THD *thd, Name_resolution_context *context,
		   const char *db_name, const char *table_name,
                   List_iterator<Item> *it, bool any_privileges);
int setup_wild(THD *thd, TABLE_LIST *tables, List<Item> &fields,
	       List<Item> *sum_func_list, uint wild_num);
bool setup_fields(THD *thd, Item** ref_pointer_array,
                  List<Item> &item, enum_mark_columns mark_used_columns,
                  List<Item> *sum_func_list, bool allow_sum_func);
bool fill_record(THD *thd, Field **field, List<Item> &values,
                 bool ignore_errors);

Field *
find_field_in_tables(THD *thd, Item_ident *item,
                     TABLE_LIST *first_table, TABLE_LIST *last_table,
                     Item **ref, find_item_error_report_type report_error,
                     bool check_privileges, bool register_tree_change);
Field *
find_field_in_table_ref(THD *thd, TABLE_LIST *table_list,
                        const char *name, uint length,
                        const char *item_name, const char *db_name,
                        const char *table_name, Item **ref,
                        bool check_privileges, bool allow_rowid,
                        uint *cached_field_index_ptr,
                        bool register_tree_change, TABLE_LIST **actual_table);
Field *
find_field_in_table(THD *thd, TABLE *table, const char *name, uint length,
                    bool allow_rowid, uint *cached_field_index_ptr);
Field *
find_field_in_table_sef(TABLE *table, const char *name);
Item ** find_item_in_list(Item *item, List<Item> &items, uint *counter,
                          find_item_error_report_type report_error,
                          enum_resolution_type *resolution);
bool setup_tables(THD *thd, Name_resolution_context *context,
                  List<TABLE_LIST> *from_clause, TABLE_LIST *tables,
                  TABLE_LIST **leaves, bool select_insert);
bool setup_tables_and_check_access(THD *thd,
                                   Name_resolution_context *context,
                                   List<TABLE_LIST> *from_clause,
                                   TABLE_LIST *tables,
                                   TABLE_LIST **leaves,
                                   bool select_insert,
                                   ulong want_access_first,
                                   ulong want_access);
bool wait_while_table_is_used(THD *thd, TABLE *table,
                              enum ha_extra_function function);
void unlink_open_table(THD *thd, TABLE *find, bool unlock);

void drop_open_table(THD *thd, TABLE *table, const char *db_name,
                     const char *table_name);
void close_all_tables_for_name(THD *thd, TABLE_SHARE *share,
                               bool remove_from_locked_tables);
void update_non_unique_table_error(TABLE_LIST *update,
                                   const char *operation,
                                   TABLE_LIST *duplicate);
int setup_conds(THD *thd, TABLE_LIST *tables, TABLE_LIST *leaves,
		COND **conds);
int setup_ftfuncs(SELECT_LEX* select);
int init_ftfuncs(THD *thd, SELECT_LEX* select, bool no_order);
bool lock_table_names(THD *thd, TABLE_LIST *table_list,
                      TABLE_LIST *table_list_end, ulong lock_wait_timeout,
                      uint flags);
bool open_tables(THD *thd, TABLE_LIST **tables, uint *counter, uint flags,
                 Prelocking_strategy *prelocking_strategy);
/* open_and_lock_tables with optional derived handling */
bool open_and_lock_tables(THD *thd, TABLE_LIST *tables,
                          bool derived, uint flags,
                          Prelocking_strategy *prelocking_strategy);
int open_and_lock_tables_derived(THD *thd, TABLE_LIST *tables, bool derived);
/* simple open_and_lock_tables without derived handling for single table */
TABLE *open_n_lock_single_table(THD *thd, TABLE_LIST *table_l,
                                thr_lock_type lock_type, uint flags);
bool open_normal_and_derived_tables(THD *thd, TABLE_LIST *tables, uint flags);
bool lock_tables(THD *thd, TABLE_LIST *tables, uint counter, uint flags);
int decide_logging_format(THD *thd, TABLE_LIST *tables);
void free_io_cache(TABLE *entry);
void intern_close_table(TABLE *entry);
bool close_thread_table(THD *thd, TABLE **table_ptr);
bool close_temporary_tables(THD *thd);
TABLE_LIST *unique_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list,
                         bool check_alias);
int drop_temporary_table(THD *thd, TABLE_LIST *table_list);
void close_temporary_table(THD *thd, TABLE *table, bool free_share,
                           bool delete_table);
void close_temporary(TABLE *table, bool free_share, bool delete_table);
bool rename_temporary_table(THD* thd, TABLE *table, const char *new_db,
			    const char *table_name);
void mysql_wait_completed_table(ALTER_PARTITION_PARAM_TYPE *lpt, TABLE *my_table);
void remove_db_from_cache(const char *db);
bool is_equal(const LEX_STRING *a, const LEX_STRING *b);

/* Functions to work with system tables. */
bool open_system_tables_for_read(THD *thd, TABLE_LIST *table_list,
                                 Open_tables_backup *backup);
void close_system_tables(THD *thd, Open_tables_backup *backup);
void close_mysql_tables(THD *thd);
TABLE *open_system_table_for_update(THD *thd, TABLE_LIST *one_table);
TABLE *open_log_table(THD *thd, TABLE_LIST *one_table, Open_tables_backup *backup);
void close_log_table(THD *thd, Open_tables_backup *backup);

TABLE *open_performance_schema_table(THD *thd, TABLE_LIST *one_table,
                                     Open_tables_state *backup);
void close_performance_schema_table(THD *thd, Open_tables_state *backup);

bool close_cached_tables(THD *thd, TABLE_LIST *tables, bool have_lock,
                         bool wait_for_refresh);
bool close_cached_connection_tables(THD *thd, bool wait_for_refresh,
                                    LEX_STRING *connect_string,
                                    bool have_lock = FALSE);
OPEN_TABLE_LIST *list_open_tables(THD *thd, const char *db, const char *wild);
bool remove_table_from_cache(THD *thd, const char *db, const char *table,
                             uint flags);
void tdc_remove_table(THD *thd, enum_tdc_remove_table_type remove_type,
                      const char *db, const char *table_name);
bool tdc_open_view(THD *thd, TABLE_LIST *table_list, const char *alias,
                   char *cache_key, uint cache_key_length,
                   MEM_ROOT *mem_root, uint flags);
void tdc_flush_unused_tables();
TABLE *find_table_for_mdl_upgrade(TABLE *list, const char *db,
                                  const char *table_name,
                                  bool no_error);
void mark_tmp_table_for_reuse(TABLE *table);
bool check_if_table_exists(THD *thd, TABLE_LIST *table, bool *exists);

extern uint  table_cache_count;
extern TABLE *unused_tables;
extern Item **not_found_item;
extern Field *not_found_field;
extern Field *view_ref_found;
extern HASH open_cache;
extern HASH table_def_cache;

/**
  clean/setup table fields and map.

  @param table        TABLE structure pointer (which should be setup)
  @param table_list   TABLE_LIST structure pointer (owner of TABLE)
  @param tablenr     table number
*/


inline void setup_table_map(TABLE *table, TABLE_LIST *table_list, uint tablenr)
{
  table->used_fields= 0;
  table->const_table= 0;
  table->null_row= 0;
  table->status= STATUS_NO_RECORD;
  table->maybe_null= table_list->outer_join;
  TABLE_LIST *embedding= table_list->embedding;
  while (!table->maybe_null && embedding)
  {
    table->maybe_null= embedding->outer_join;
    embedding= embedding->embedding;
  }
  table->tablenr= tablenr;
  table->map= (table_map) 1 << tablenr;
  table->force_index= table_list->force_index;
  table->force_index_order= table->force_index_group= 0;
  table->covering_keys= table->s->keys_for_keyread;
  table->merge_keys.clear_all();
}

inline TABLE_LIST *find_table_in_global_list(TABLE_LIST *table,
                                             const char *db_name,
                                             const char *table_name)
{
  return find_table_in_list(table, &TABLE_LIST::next_global,
                            db_name, table_name);
}

inline TABLE_LIST *find_table_in_local_list(TABLE_LIST *table,
                                            const char *db_name,
                                            const char *table_name)
{
  return find_table_in_list(table, &TABLE_LIST::next_local,
                            db_name, table_name);
}


inline bool setup_fields_with_no_wrap(THD *thd, Item **ref_pointer_array,
                                      List<Item> &item,
                                      enum_mark_columns mark_used_columns,
                                      List<Item> *sum_func_list,
                                      bool allow_sum_func)
{
  bool res;
  thd->lex->select_lex.no_wrap_view_item= TRUE;
  res= setup_fields(thd, ref_pointer_array, item, mark_used_columns,
                    sum_func_list, allow_sum_func);
  thd->lex->select_lex.no_wrap_view_item= FALSE;
  return res;
}

/**
  An abstract class for a strategy specifying how the prelocking
  algorithm should extend the prelocking set while processing
  already existing elements in the set.
*/

class Prelocking_strategy
{
public:
  virtual ~Prelocking_strategy() { }

  virtual bool handle_routine(THD *thd, Query_tables_list *prelocking_ctx,
                              Sroutine_hash_entry *rt, sp_head *sp,
                              bool *need_prelocking) = 0;
  virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx,
                            TABLE_LIST *table_list, bool *need_prelocking) = 0;
  virtual bool handle_view(THD *thd, Query_tables_list *prelocking_ctx,
                           TABLE_LIST *table_list, bool *need_prelocking)= 0;
};


/**
  A Strategy for prelocking algorithm suitable for DML statements.

  Ensures that all tables used by all statement's SF/SP/triggers and
  required for foreign key checks are prelocked and SF/SPs used are
  cached.
*/

class DML_prelocking_strategy : public Prelocking_strategy
{
public:
  virtual bool handle_routine(THD *thd, Query_tables_list *prelocking_ctx,
                              Sroutine_hash_entry *rt, sp_head *sp,
                              bool *need_prelocking);
  virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx,
                            TABLE_LIST *table_list, bool *need_prelocking);
  virtual bool handle_view(THD *thd, Query_tables_list *prelocking_ctx,
                           TABLE_LIST *table_list, bool *need_prelocking);
};


/**
  A strategy for prelocking algorithm to be used for LOCK TABLES
  statement.
*/

class Lock_tables_prelocking_strategy : public DML_prelocking_strategy
{
  virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx,
                            TABLE_LIST *table_list, bool *need_prelocking);
};


/**
  Strategy for prelocking algorithm to be used for ALTER TABLE statements.

  Unlike DML or LOCK TABLES strategy, it doesn't
  prelock triggers, views or stored routines, since they are not
  used during ALTER.
*/

class Alter_table_prelocking_strategy : public Prelocking_strategy
{
public:

  Alter_table_prelocking_strategy(Alter_info *alter_info)
    : m_alter_info(alter_info)
  {}

  virtual bool handle_routine(THD *thd, Query_tables_list *prelocking_ctx,
                              Sroutine_hash_entry *rt, sp_head *sp,
                              bool *need_prelocking);
  virtual bool handle_table(THD *thd, Query_tables_list *prelocking_ctx,
                            TABLE_LIST *table_list, bool *need_prelocking);
  virtual bool handle_view(THD *thd, Query_tables_list *prelocking_ctx,
                           TABLE_LIST *table_list, bool *need_prelocking);

private:
  Alter_info *m_alter_info;
};


inline bool
open_tables(THD *thd, TABLE_LIST **tables, uint *counter, uint flags)
{
  DML_prelocking_strategy prelocking_strategy;

  return open_tables(thd, tables, counter, flags, &prelocking_strategy);
}


/* open_and_lock_tables with derived handling */
inline bool open_and_lock_tables(THD *thd, TABLE_LIST *tables,
                                 bool derived, uint flags)
{
  DML_prelocking_strategy prelocking_strategy;

  return open_and_lock_tables(thd, tables, derived, flags,
                              &prelocking_strategy);
}


/**
  A context of open_tables() function, used to recover
  from a failed open_table() or open_routine() attempt.
*/

class Open_table_context
{
public:
  enum enum_open_table_action
  {
    OT_NO_ACTION= 0,
    OT_MDL_CONFLICT,
    OT_WAIT_TDC,
    OT_DISCOVER,
    OT_REPAIR
  };
  Open_table_context(THD *thd, uint flags);

  bool recover_from_failed_open(THD *thd);
  bool request_backoff_action(enum_open_table_action action_arg,
                              TABLE_LIST *table);

  void add_request(MDL_request *request)
  { m_mdl_requests.push_front(request); }

  bool can_recover_from_failed_open() const
  { return m_action != OT_NO_ACTION; }

  /**
    When doing a back-off, we close all tables acquired by this
    statement.  Return an MDL savepoint taken at the beginning of
    the statement, so that we can rollback to it before waiting on
    locks.
  */
  MDL_ticket *start_of_statement_svp() const
  {
    return m_start_of_statement_svp;
  }

  inline ulong get_timeout() const
  {
    return m_timeout;
  }

  uint get_flags() const { return m_flags; }
private:
  /** List of requests for all locks taken so far. Used for waiting on locks. */
  MDL_request_list m_mdl_requests;
  /**
    For OT_DISCOVER and OT_REPAIR actions, the table list element for
    the table which definition should be re-discovered or which
    should be repaired.
  */
  TABLE_LIST *m_failed_table;
  MDL_ticket *m_start_of_statement_svp;
  /**
    Lock timeout in seconds. Initialized to LONG_TIMEOUT when opening system
    tables or to the "lock_wait_timeout" system variable for regular tables.
  */
  ulong m_timeout;
  /* open_table() flags. */
  uint m_flags;
  /** Back off action. */
  enum enum_open_table_action m_action;
  /**
    Whether we had any locks when this context was created.
    If we did, they are from the previous statement of a transaction,
    and we can't safely do back-off (and release them).
  */
  bool m_has_locks;
};


#endif /* SQL_BASE_INCLUDED */