path: root/sql/table.h

/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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 */


/* Structs that defines the TABLE */

class Item;				/* Needed by ORDER */
class GRANT_TABLE;
class st_select_lex_unit;
class st_select_lex;
class COND_EQUAL;

/* Order clause list element */

typedef struct st_order {
  struct st_order *next;
  Item	 **item;			/* Point at item in select fields */
  Item	 *item_ptr;			/* Storage for initial item */
  Item   **item_copy;			/* For SPs; the original item ptr */
  int    counter;                       /* position in SELECT list, correct
                                           only if counter_used is true*/
  bool	 asc;				/* true if ascending */
  bool	 free_me;			/* true if item isn't shared  */
  bool	 in_field_list;			/* true if in select field list */
  bool   counter_used;                  /* parameter was counter of columns */
  Field  *field;			/* If tmp-table group */
  char	 *buff;				/* If tmp-table group */
  table_map used,depend_map;
} ORDER;

typedef struct st_grant_info
{
  GRANT_TABLE *grant_table;
  uint version;
  ulong privilege;
  ulong want_privilege;
} GRANT_INFO;

enum tmp_table_type {NO_TMP_TABLE=0, TMP_TABLE=1, TRANSACTIONAL_TMP_TABLE=2};

enum frm_type_enum
{
  FRMTYPE_ERROR= 0,
  FRMTYPE_TABLE,
  FRMTYPE_VIEW
};

typedef struct st_filesort_info
{
  IO_CACHE *io_cache;           /* If sorted through filebyte                */
  byte     *addon_buf;          /* Pointer to a buffer if sorted with fields */
  uint      addon_length;       /* Length of the buffer                      */
  struct st_sort_addon_field *addon_field;     /* Pointer to the fields info */
  void    (*unpack)(struct st_sort_addon_field *, byte *); /* To unpack back */
  byte     *record_pointers;    /* If sorted in memory                       */
  ha_rows   found_records;      /* How many records in sort                  */
} FILESORT_INFO;


/*
  Values in this enum are used to indicate during which operations value
  of TIMESTAMP field should be set to current timestamp.
*/
enum timestamp_auto_set_type
{
  TIMESTAMP_NO_AUTO_SET= 0, TIMESTAMP_AUTO_SET_ON_INSERT= 1,
  TIMESTAMP_AUTO_SET_ON_UPDATE= 2, TIMESTAMP_AUTO_SET_ON_BOTH= 3
};

/* Table cache entry struct */

class Field_timestamp;
class Field_blob;
class Table_triggers_list;

struct st_table {
  handler *file;
  Field **field;			/* Pointer to fields */
  Field_blob **blob_field;		/* Pointer to blob fields */
  /* hash of field names (contains pointers to elements of field array) */
  HASH	name_hash;
  byte *record[2];			/* Pointer to records */
  byte *default_values;         	/* Default values for INSERT */
  byte *insert_values;                  /* used by INSERT ... UPDATE */
  uint fields;				/* field count */
  uint reclength;			/* Recordlength */
  uint rec_buff_length;
  uint keys,key_parts,primary_key,max_key_length,max_unique_length;
  uint total_key_length;
  uint uniques;
  uint null_fields;			/* number of null fields */
  uint blob_fields;			/* number of blob fields */
  key_map keys_in_use, keys_for_keyread, read_only_keys;
  key_map quick_keys, used_keys, keys_in_use_for_query;
  KEY  *key_info;			/* data of keys in database */
  TYPELIB keynames;			/* Pointers to keynames */
  ha_rows max_rows;			/* create information */
  ha_rows min_rows;			/* create information */
  ulong   avg_row_length;		/* create information */
  ulong   raid_chunksize;
  TYPELIB fieldnames;			/* Pointer to fieldnames */
  TYPELIB *intervals;			/* pointer to interval info */
  enum db_type db_type;			/* table_type for handler */
  enum row_type row_type;		/* How rows are stored */
  uint db_create_options;		/* Create options from database */
  uint db_options_in_use;		/* Options in use */
  uint db_record_offset;		/* if HA_REC_IN_SEQ */
  uint db_stat;				/* mode of file as in handler.h */
  uint raid_type,raid_chunks;
  uint status;				/* Used by postfix.. */
  uint system;				/* Set if system record */

  /*
    If this table has TIMESTAMP field with auto-set property (pointed by
    timestamp_field member) then this variable indicates during which
    operations (insert only/on update/in both cases) we should set this
    field to current timestamp. If there are no such field in this table
    or we should not automatically set its value during execution of current
    statement then the variable contains TIMESTAMP_NO_AUTO_SET (i.e. 0).

    Value of this variable is set for each statement in open_table() and
    if needed cleared later in statement processing code (see mysql_update()
    as example).
  */
  timestamp_auto_set_type timestamp_field_type;
  /* Index of auto-updated TIMESTAMP field in field array */
  uint timestamp_field_offset;
  
  uint next_number_index;
  uint blob_ptr_size;			/* 4 or 8 */
  uint next_number_key_offset;
  int current_lock;			/* Type of lock on table */
  enum tmp_table_type tmp_table;
  my_bool copy_blobs;			/* copy_blobs when storing */
  my_bool null_row;			/* All columns are null */
  my_bool maybe_null,outer_join;	/* Used with OUTER JOIN */
  my_bool force_index;
  my_bool distinct,const_table,no_rows;
  my_bool key_read;
  my_bool crypted;
  my_bool db_low_byte_first;		/* Portable row format */
  my_bool locked_by_flush;
  my_bool locked_by_name;
  my_bool fulltext_searched;
  my_bool crashed;
  my_bool is_view;
  my_bool no_keyread, no_cache;
  my_bool clear_query_id;               /* To reset query_id for tables and cols */
  my_bool auto_increment_field_not_null;
  my_bool insert_or_update;             /* Can be used by the handler */
  Field *next_number_field,		/* Set if next_number is activated */
	*found_next_number_field,	/* Set on open */
        *rowid_field;
  Field_timestamp *timestamp_field;
#if MYSQL_VERSION_ID < 40100
  /*
    Indicates whenever we have to set field_length members of all TIMESTAMP
    fields to 19 (to honour 'new_mode' variable) or to original
    field_length values.
  */
  my_bool timestamp_mode;
#endif
  my_string comment;			/* Comment about table */
  CHARSET_INFO *table_charset;		/* Default charset of string fields */
  REGINFO reginfo;			/* field connections */
  MEM_ROOT mem_root;
  GRANT_INFO grant;
  /* Table's triggers, 0 if there are no of them */
  Table_triggers_list *triggers;

  /* A pair "database_name\0table_name\0", widely used as simply a db name */
  char		*table_cache_key;
  char		*table_name,*real_name,*path;
  uint		key_length;		/* Length of key */
  uint		tablenr,used_fields,null_bytes;
  table_map	map;                    /* ID bit of table (1,2,4,8,16...) */
  ulong		version,flush_version;
  uchar		*null_flags;
  FILESORT_INFO sort;
  ORDER		*group;
  ha_rows	quick_rows[MAX_KEY];
  uint		quick_key_parts[MAX_KEY];
  key_part_map  const_key_parts[MAX_KEY];
  ulong		query_id;
  uchar		frm_version;
  uint          temp_pool_slot;		/* Used by intern temp tables */
  struct st_table_list *pos_in_table_list;/* Element referring to this table */
  /* number of select if it is derived table */
  uint          derived_select_number;
  THD		*in_use;		/* Which thread uses this */
  struct st_table *next,*prev;
};


#define JOIN_TYPE_LEFT	1
#define JOIN_TYPE_RIGHT	2

#define VIEW_ALGORITHM_UNDEFINED	0
#define VIEW_ALGORITHM_TMPTABLE	1
#define VIEW_ALGORITHM_MERGE		2

/* view WITH CHECK OPTION parameter options */
#define VIEW_CHECK_NONE       0
#define VIEW_CHECK_LOCAL      1
#define VIEW_CHECK_CASCADED   2

/* result of view WITH CHECK OPTION parameter check */
#define VIEW_CHECK_OK         0
#define VIEW_CHECK_ERROR      1
#define VIEW_CHECK_SKIP       2

struct st_lex;
struct select_union;

typedef struct st_table_list
{
  /* link in a local table list (used by SQL_LIST) */
  struct st_table_list *next_local;
  /* link in a global list of all queries tables */
  struct st_table_list *next_global, **prev_global;
  char		*db, *alias, *real_name;
  char          *option;                /* Used by cache index  */
  Item		*on_expr;		/* Used with outer join */
  COND_EQUAL    *cond_equal;            /* Used with outer join */
  struct st_table_list *natural_join;	/* natural join on this table*/
  /* ... join ... USE INDEX ... IGNORE INDEX */
  List<String>	*use_index, *ignore_index;
  TABLE         *table;                 /* opened table */
  /*
    select_result for derived table to pass it from table creation to table
    filling procedure
  */
  select_union  *derived_result;
  /*
    Reference from aux_tables to local list entry of main select of
    multi-delete statement:
    delete t1 from t2,t1 where t1.a<'B' and t2.b=t1.b;
    here it will be reference of first occurrence of t1 to second (as you
    can see this lists can't be merged)
  */
  st_table_list	*correspondent_table;
  st_select_lex_unit *derived;		/* SELECT_LEX_UNIT of derived table */
  /* link to select_lex where this table was used */
  st_select_lex	*select_lex;
  st_lex	*view;			/* link on VIEW lex for merging */
  Item		**field_translation;	/* array of VIEW fields */
  /* ancestor of this table (VIEW merge algorithm) */
  st_table_list	*ancestor;
  /* most upper view this table belongs to */
  st_table_list	*belong_to_view;
  /* next_global before adding VIEW tables */
  st_table_list	*old_next;
  Item          *where;                 /* VIEW WHERE clause condition */
  Item          *check_option;          /* WITH CHECK OPTION condition */
  LEX_STRING	query;			/* text of (CRETE/SELECT) statement */
  LEX_STRING	md5;			/* md5 of query text */
  LEX_STRING	source;			/* source of CREATE VIEW */
  LEX_STRING	view_db;		/* saved view database */
  LEX_STRING	view_name;		/* saved view name */
  LEX_STRING	timestamp;		/* GMT time stamp of last operation */
  ulonglong	file_version;		/* version of file's field set */
  ulonglong     updatable_view;         /* VIEW can be updated */
  ulonglong	revision;		/* revision control number */
  ulonglong	algorithm;		/* 0 any, 1 tmp tables , 2 merging */
  ulonglong     with_check;             /* WITH CHECK OPTION */
  /*
    effective value of WITH CHECK OPTION (differ for temporary table
    algorithm)
  */
  uint8         effective_with_check;
  uint          effective_algorithm;    /* which algorithm was really used */
  GRANT_INFO	grant;
  thr_lock_type lock_type;
  uint		outer_join;		/* Which join type */
  uint		shared;			/* Used in multi-upd */
  uint32        db_length, real_name_length;
  bool          updatable;		/* VIEW/TABLE can be updated now */
  bool		straight;		/* optimize with prev table */
  bool          updating;               /* for replicate-do/ignore table */
  bool		force_index;		/* prefer index over table scan */
  bool          ignore_leaves;          /* preload only non-leaf nodes */
  bool          no_where_clause;        /* do not attach WHERE to SELECT */
  table_map     dep_tables;             /* tables the table depends on      */
  table_map     on_expr_dep_tables;     /* tables on expression depends on  */
  struct st_nested_join *nested_join;   /* if the element is a nested join  */
  st_table_list *embedding;             /* nested join containing the table */
  List<struct st_table_list> *join_list;/* join list the table belongs to   */
  bool		cacheable_table;	/* stop PS caching */
  /* used in multi-upd/views privilege check */
  bool		table_in_first_from_clause;
  bool		skip_temporary;		/* this table shouldn't be temporary */
  bool          setup_is_done;          /* setup_tables() is done */
  /* TRUE if this merged view contain auto_increment field */
  bool          contain_auto_increment;
  /* FRMTYPE_ERROR if any type is acceptable */
  enum frm_type_enum required_type;
  char		timestamp_buffer[20];	/* buffer for timestamp (19+1) */

  void calc_md5(char *buffer);
  void set_ancestor();
  int view_check_option(THD *thd, bool ignore_failure);
  bool setup_ancestor(THD *thd, Item **conds, uint8 check_option);
  void cleanup_items();
  bool placeholder() {return derived || view; }
  void print(THD *thd, String *str);
  inline st_table_list *next_independent()
  {
    if (view)
      return old_next;
    return next_global;
  }
} TABLE_LIST;

class Item;

class Field_iterator: public Sql_alloc
{
public:
  virtual ~Field_iterator() {}
  virtual void set(TABLE_LIST *)= 0;
  virtual void next()= 0;
  virtual bool end_of_fields()= 0;              /* Return 1 at end of list */
  virtual const char *name()= 0;
  virtual Item *item(THD *)= 0;
  virtual Field *field()= 0;
};


class Field_iterator_table: public Field_iterator
{
  Field **ptr;
public:
  Field_iterator_table() :ptr(0) {}
  void set(TABLE_LIST *table) { ptr= table->table->field; }
  void set_table(TABLE *table) { ptr= table->field; }
  void next() { ptr++; }
  bool end_of_fields() { return *ptr == 0; }
  const char *name();
  Item *item(THD *thd);
  Field *field() { return *ptr; }
};


class Field_iterator_view: public Field_iterator
{
  Item **ptr, **array_end;
public:
  Field_iterator_view() :ptr(0), array_end(0) {}
  void set(TABLE_LIST *table);
  void next() { ptr++; }
  bool end_of_fields() { return ptr == array_end; }
  const char *name();
  Item *item(THD *thd) { return *ptr; }
  Field *field() { return 0; }
};

typedef struct st_nested_join
{
  List<TABLE_LIST>  join_list;       /* list of elements in the nested join */
  table_map         used_tables;     /* bitmap of tables in the nested join */
  table_map         not_null_tables; /* tables that rejects nulls           */
  struct st_join_table *first_nested;/* the first nested table in the plan  */
  uint              counter;         /* to count tables in the nested join  */
} NESTED_JOIN;

typedef struct st_changed_table_list
{
  struct	st_changed_table_list *next;
  char		*key;
  uint32        key_length;
} CHANGED_TABLE_LIST;

typedef struct st_open_table_list{
  struct st_open_table_list *next;
  char	*db,*table;
  uint32 in_use,locked;
} OPEN_TABLE_LIST;