handler.h

#ifndef HANDLER_INCLUDED
#define HANDLER_INCLUDED

/*
   Copyright (c) 2000, 2014, 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
*/

/* Definitions for parameters to do with handler-routines */

#include "my_pthread.h"
#include <algorithm>
#include "sql_const.h"
#include "mysqld.h"                             /* server_id */
#include "structs.h"                            /* SHOW_COMP_OPTION */

#include <my_global.h>
#include <my_compare.h>
#include <ft_global.h>


class MY_LOCALE;
struct TABLE_LIST;
struct LEX;
struct TABLE;
typedef struct st_changed_table_list CHANGED_TABLE_LIST;
typedef ulonglong sql_mode_t;



/* Bits in table_flags() to show what database can do */

#define HA_NO_TRANSACTIONS     (1 << 0) /* Doesn't support transactions */
#define HA_PARTIAL_COLUMN_READ (1 << 1) /* read may not return all columns */
#define HA_TABLE_SCAN_ON_INDEX (1 << 2) /* No separate data/index file */
/*
  The following should be set if the following is not true when scanning
  a table with rnd_next()
  - We will see all rows (including deleted ones)
  - Row positions are 'table->s->db_record_offset' apart
  If this flag is not set, filesort will do a position() call for each matched
  row to be able to find the row later.
*/
#define HA_REC_NOT_IN_SEQ      (1 << 3)
#define HA_CAN_GEOMETRY        (1 << 4)
/*
  Reading keys in random order is as fast as reading keys in sort order
  (Used in records.cc to decide if we should use a record cache and by
  filesort to decide if we should sort key + data or key + pointer-to-row
*/
#define HA_FAST_KEY_READ       (1 << 5)
/*
  Set the following flag if we on delete should force all key to be read
  and on update read all keys that changes
*/
#define HA_REQUIRES_KEY_COLUMNS_FOR_DELETE (1 << 6)
#define HA_NULL_IN_KEY         (1 << 7) /* One can have keys with NULL */
#define HA_DUPLICATE_POS       (1 << 8)    /* position() gives dup row */
#define HA_NO_BLOBS            (1 << 9) /* Doesn't support blobs */
#define HA_CAN_INDEX_BLOBS     (1 << 10)
#define HA_AUTO_PART_KEY       (1 << 11) /* auto-increment in multi-part key */
#define HA_REQUIRE_PRIMARY_KEY (1 << 12) /* .. and can't create a hidden one */
#define HA_STATS_RECORDS_IS_EXACT (1 << 13) /* stats.records is exact */
/*
  INSERT_DELAYED only works with handlers that uses MySQL internal table
  level locks
*/
#define HA_CAN_INSERT_DELAYED  (1 << 14)
/*
  If we get the primary key columns for free when we do an index read
  (usually, it also implies that HA_PRIMARY_KEY_REQUIRED_FOR_POSITION
  flag is set).
*/
#define HA_PRIMARY_KEY_IN_READ_INDEX (1 << 15)
/*
  If HA_PRIMARY_KEY_REQUIRED_FOR_POSITION is set, it means that to position()
  uses a primary key given by the record argument.
  Without primary key, we can't call position().
  If not set, the position is returned as the current rows position
  regardless of what argument is given.
*/ 
#define HA_PRIMARY_KEY_REQUIRED_FOR_POSITION (1 << 16) 
#define HA_CAN_RTREEKEYS       (1 << 17)
#define HA_NOT_DELETE_WITH_CACHE (1 << 18)
/*
  The following is we need to a primary key to delete (and update) a row.
  If there is no primary key, all columns needs to be read on update and delete
*/
#define HA_PRIMARY_KEY_REQUIRED_FOR_DELETE (1 << 19)
#define HA_NO_PREFIX_CHAR_KEYS (1 << 20)
#define HA_CAN_FULLTEXT        (1 << 21)
#define HA_CAN_SQL_HANDLER     (1 << 22)
#define HA_NO_AUTO_INCREMENT   (1 << 23)
#define HA_HAS_CHECKSUM        (1 << 24)
/* Table data are stored in separate files (for lower_case_table_names) */
#define HA_FILE_BASED	       (1 << 26)
#define HA_NO_VARCHAR	       (1 << 27)
#define HA_CAN_BIT_FIELD       (1 << 28) /* supports bit fields */
#define HA_ANY_INDEX_MAY_BE_UNIQUE (1 << 30)
#define HA_NO_COPY_ON_ALTER    (LL(1) << 31)
#define HA_HAS_RECORDS	       (LL(1) << 32) /* records() gives exact count*/
/* Has it's own method of binlog logging */
#define HA_HAS_OWN_BINLOGGING  (LL(1) << 33)

/*
  Note: the following includes binlog and closing 0.
  so: innodb + bdb + ndb + binlog + myisam + myisammrg + archive +
      example + csv + heap + blackhole + federated + 0
  (yes, the sum is deliberately inaccurate)
  TODO remove the limit, use dynarrays
*/
#define MAX_HA 15
#define HA_LEX_CREATE_TMP_TABLE	1
#define HA_LEX_CREATE_IF_NOT_EXISTS 2
#define HA_LEX_CREATE_TABLE_LIKE 4
#define HA_OPTION_NO_CHECKSUM	(1L << 17)
#define HA_OPTION_NO_DELAY_KEY_WRITE (1L << 18)
#define HA_MAX_REC_LENGTH	65535U



// WITH CONSISTENT SNAPSHOT option
static const uint MYSQL_START_TRANS_OPT_WITH_CONS_SNAPSHOT = 1;
// READ ONLY option
static const uint MYSQL_START_TRANS_OPT_READ_ONLY          = 2;
// READ WRITE option
static const uint MYSQL_START_TRANS_OPT_READ_WRITE         = 4;

enum legacy_db_type
{
  DB_TYPE_UNKNOWN=0,DB_TYPE_DIAB_ISAM=1,
  DB_TYPE_HASH,DB_TYPE_MISAM,DB_TYPE_PISAM,
  DB_TYPE_RMS_ISAM, DB_TYPE_HEAP, DB_TYPE_ISAM,
  DB_TYPE_MRG_ISAM, DB_TYPE_MYISAM, DB_TYPE_MRG_MYISAM,
  DB_TYPE_BERKELEY_DB, DB_TYPE_INNODB,
  DB_TYPE_GEMINI, DB_TYPE_NDBCLUSTER,
  DB_TYPE_EXAMPLE_DB, DB_TYPE_ARCHIVE_DB, DB_TYPE_CSV_DB,
  DB_TYPE_FEDERATED_DB,
  DB_TYPE_BLACKHOLE_DB,
  DB_TYPE_PARTITION_DB,
  DB_TYPE_BINLOG,
  DB_TYPE_SOLID,
  DB_TYPE_PBXT,
  DB_TYPE_TABLE_FUNCTION,
  DB_TYPE_MEMCACHE,
  DB_TYPE_FALCON,
  DB_TYPE_MARIA,
  /** Performance schema engine. */
  DB_TYPE_PERFORMANCE_SCHEMA,
  DB_TYPE_TOKUDB=41,
  DB_TYPE_FIRST_DYNAMIC=42,
  DB_TYPE_DEFAULT=127 // Must be last
};

enum row_type { ROW_TYPE_NOT_USED=-1, ROW_TYPE_DEFAULT, ROW_TYPE_FIXED,
		ROW_TYPE_DYNAMIC, ROW_TYPE_COMPRESSED,
		ROW_TYPE_REDUNDANT, ROW_TYPE_COMPACT,
                /** Unused. Reserved for future versions. */
                ROW_TYPE_PAGE,
                ROW_TYPE_TOKU_UNCOMPRESSED, ROW_TYPE_TOKU_ZLIB,
                ROW_TYPE_TOKU_QUICKLZ, ROW_TYPE_TOKU_LZMA,
                ROW_TYPE_TOKU_FAST, ROW_TYPE_TOKU_SMALL };

/* Specifies data storage format for individual columns */
enum column_format_type {
  COLUMN_FORMAT_TYPE_DEFAULT=   0, /* Not specified (use engine default) */
  COLUMN_FORMAT_TYPE_FIXED=     1, /* FIXED format */
  COLUMN_FORMAT_TYPE_DYNAMIC=   2  /* DYNAMIC format */
};


/* struct to hold information about the table that should be created */

/* Bits in used_fields */
#define HA_CREATE_USED_AUTO             (1L << 0)
#define HA_CREATE_USED_RAID             (1L << 1) //RAID is no longer availble
#define HA_CREATE_USED_UNION            (1L << 2)
#define HA_CREATE_USED_INSERT_METHOD    (1L << 3)
#define HA_CREATE_USED_MIN_ROWS         (1L << 4)
#define HA_CREATE_USED_MAX_ROWS         (1L << 5)
#define HA_CREATE_USED_AVG_ROW_LENGTH   (1L << 6)
#define HA_CREATE_USED_PACK_KEYS        (1L << 7)
#define HA_CREATE_USED_CHARSET          (1L << 8)
#define HA_CREATE_USED_DEFAULT_CHARSET  (1L << 9)
#define HA_CREATE_USED_DATADIR          (1L << 10)
#define HA_CREATE_USED_INDEXDIR         (1L << 11)
#define HA_CREATE_USED_ENGINE           (1L << 12)
#define HA_CREATE_USED_CHECKSUM         (1L << 13)
#define HA_CREATE_USED_DELAY_KEY_WRITE  (1L << 14)
#define HA_CREATE_USED_ROW_FORMAT       (1L << 15)
#define HA_CREATE_USED_COMMENT          (1L << 16)
#define HA_CREATE_USED_PASSWORD         (1L << 17)
#define HA_CREATE_USED_CONNECTION       (1L << 18)
#define HA_CREATE_USED_KEY_BLOCK_SIZE   (1L << 19)
/** Unused. Reserved for future versions. */
#define HA_CREATE_USED_TRANSACTIONAL    (1L << 20)
/** Unused. Reserved for future versions. */
#define HA_CREATE_USED_PAGE_CHECKSUM    (1L << 21)
/** This is set whenever STATS_PERSISTENT=0|1|default has been
specified in CREATE/ALTER TABLE. See also HA_OPTION_STATS_PERSISTENT in
include/my_base.h. It is possible to distinguish whether
STATS_PERSISTENT=default has been specified or no STATS_PERSISTENT= is
given at all. */
#define HA_CREATE_USED_STATS_PERSISTENT (1L << 22)
/**
   This is set whenever STATS_AUTO_RECALC=0|1|default has been
   specified in CREATE/ALTER TABLE. See enum_stats_auto_recalc.
   It is possible to distinguish whether STATS_AUTO_RECALC=default
   has been specified or no STATS_AUTO_RECALC= is given at all.
*/
#define HA_CREATE_USED_STATS_AUTO_RECALC (1L << 23)
/**
   This is set whenever STATS_SAMPLE_PAGES=N|default has been
   specified in CREATE/ALTER TABLE. It is possible to distinguish whether
   STATS_SAMPLE_PAGES=default has been specified or no STATS_SAMPLE_PAGES= is
   given at all.
*/
#define HA_CREATE_USED_STATS_SAMPLE_PAGES (1L << 24)



typedef ulonglong my_xid; // this line is the same as in log_event.h
#define MYSQL_XID_PREFIX "MySQLXid"
#define MYSQL_XID_PREFIX_LEN 8 // must be a multiple of 8
#define MYSQL_XID_OFFSET (MYSQL_XID_PREFIX_LEN)
#define MYSQL_XID_GTRID_LEN (MYSQL_XID_OFFSET+sizeof(my_xid))

#define XIDDATASIZE MYSQL_XIDDATASIZE
#define MAXGTRIDSIZE 64
#define MAXBQUALSIZE 64


/**
  struct xid_t is binary compatible with the XID structure as
  in the X/Open CAE Specification, Distributed Transaction Processing:
  The XA Specification, X/Open Company Ltd., 1991.
  http://www.opengroup.org/bookstore/catalog/c193.htm

  @see MYSQL_XID in mysql/plugin.h
*/
struct xid_t {
  long formatID;
  long gtrid_length;
  long bqual_length;
  char data[XIDDATASIZE];  // not \0-terminated !

  xid_t() {}                                /* Remove gcc warning */  
  bool eq(struct xid_t *xid)
  { return eq(xid->gtrid_length, xid->bqual_length, xid->data); }
  bool eq(long g, long b, const char *d)
  { return g == gtrid_length && b == bqual_length && !memcmp(d, data, g+b); }
  void set(struct xid_t *xid)
  { memcpy(this, xid, xid->length()); }
  void set(long f, const char *g, long gl, const char *b, long bl)
  {
    formatID= f;
    memcpy(data, g, gtrid_length= gl);
    memcpy(data+gl, b, bqual_length= bl);
  }
  void set(ulonglong xid)
  {
    my_xid tmp;
    formatID= 1;
    set(MYSQL_XID_PREFIX_LEN, 0, MYSQL_XID_PREFIX);
    tmp= xid;
    memcpy(data+MYSQL_XID_OFFSET, &tmp, sizeof(tmp));
    gtrid_length=MYSQL_XID_GTRID_LEN;
  }
  void set(long g, long b, const char *d)
  {
    formatID= 1;
    gtrid_length= g;
    bqual_length= b;
    memcpy(data, d, g+b);
  }
  bool is_null() { return formatID == -1; }
  void null() { formatID= -1; }
  my_xid quick_get_my_xid()
  {
    my_xid tmp;
    memcpy(&tmp, data+MYSQL_XID_OFFSET, sizeof(tmp));
    return tmp;
  }
  my_xid get_my_xid()
  {
    return gtrid_length == MYSQL_XID_GTRID_LEN && bqual_length == 0 &&
           !memcmp(data, MYSQL_XID_PREFIX, MYSQL_XID_PREFIX_LEN) ?
           quick_get_my_xid() : 0;
  }
  uint length()
  {
    return sizeof(formatID)+sizeof(gtrid_length)+sizeof(bqual_length)+
           gtrid_length+bqual_length;
  }
  uchar *key()
  {
    return (uchar *)&gtrid_length;
  }
  uint key_length()
  {
    return sizeof(gtrid_length)+sizeof(bqual_length)+gtrid_length+bqual_length;
  }
};
typedef struct xid_t XID;

/* for recover() handlerton call */
#define MIN_XID_LIST_SIZE  128
#define MAX_XID_LIST_SIZE  (1024*128)

/*
  These structures are used to pass information from a set of SQL commands
  on add/drop/change tablespace definitions to the proper hton.
*/
#define UNDEF_NODEGROUP 65535
enum ts_command_type
{
  TS_CMD_NOT_DEFINED = -1,
  CREATE_TABLESPACE = 0,
  ALTER_TABLESPACE = 1,
  CREATE_LOGFILE_GROUP = 2,
  ALTER_LOGFILE_GROUP = 3,
  DROP_TABLESPACE = 4,
  DROP_LOGFILE_GROUP = 5,
  CHANGE_FILE_TABLESPACE = 6,
  ALTER_ACCESS_MODE_TABLESPACE = 7
};

enum ts_alter_tablespace_type
{
  TS_ALTER_TABLESPACE_TYPE_NOT_DEFINED = -1,
  ALTER_TABLESPACE_ADD_FILE = 1,
  ALTER_TABLESPACE_DROP_FILE = 2
};

enum tablespace_access_mode
{
  TS_NOT_DEFINED= -1,
  TS_READ_ONLY = 0,
  TS_READ_WRITE = 1,
  TS_NOT_ACCESSIBLE = 2
};

struct handlerton;
class st_alter_tablespace : public Sql_alloc
{
  public:
  const char *tablespace_name;
  const char *logfile_group_name;
  enum ts_command_type ts_cmd_type;
  enum ts_alter_tablespace_type ts_alter_tablespace_type;
  const char *data_file_name;
  const char *undo_file_name;
  const char *redo_file_name;
  ulonglong extent_size;
  ulonglong undo_buffer_size;
  ulonglong redo_buffer_size;
  ulonglong initial_size;
  ulonglong autoextend_size;
  ulonglong max_size;
  uint nodegroup_id;
  handlerton *storage_engine;
  bool wait_until_completed;
  const char *ts_comment;
  enum tablespace_access_mode ts_access_mode;
  st_alter_tablespace()
  {
    tablespace_name= NULL;
    logfile_group_name= "DEFAULT_LG"; //Default log file group
    ts_cmd_type= TS_CMD_NOT_DEFINED;
    data_file_name= NULL;
    undo_file_name= NULL;
    redo_file_name= NULL;
    extent_size= 1024*1024;        //Default 1 MByte
    undo_buffer_size= 8*1024*1024; //Default 8 MByte
    redo_buffer_size= 8*1024*1024; //Default 8 MByte
    initial_size= 128*1024*1024;   //Default 128 MByte
    autoextend_size= 0;            //No autoextension as default
    max_size= 0;                   //Max size == initial size => no extension
    storage_engine= NULL;
    nodegroup_id= UNDEF_NODEGROUP;
    wait_until_completed= TRUE;
    ts_comment= NULL;
    ts_access_mode= TS_NOT_DEFINED;
  }
};

/*
  Make sure that the order of schema_tables and enum_schema_tables are the same.
*/
enum enum_schema_tables
{
  SCH_CHARSETS= 0,
  SCH_CLIENT_STATS,
  SCH_COLLATIONS,
  SCH_COLLATION_CHARACTER_SET_APPLICABILITY,
  SCH_COLUMNS,
  SCH_COLUMN_PRIVILEGES,
  SCH_INDEX_STATS,
  SCH_ENGINES,
  SCH_EVENTS,
  SCH_FILES,
  SCH_GLOBAL_STATUS,
  SCH_GLOBAL_TEMPORARY_TABLES,
  SCH_GLOBAL_VARIABLES,
  SCH_KEY_COLUMN_USAGE,
  SCH_OPEN_TABLES,
  SCH_OPTIMIZER_TRACE,
  SCH_PARAMETERS,
  SCH_PARTITIONS,
  SCH_PLUGINS,
  SCH_PROCESSLIST,
  SCH_PROFILES,
  SCH_REFERENTIAL_CONSTRAINTS,
  SCH_PROCEDURES,
  SCH_SCHEMATA,
  SCH_SCHEMA_PRIVILEGES,
  SCH_SESSION_STATUS,
  SCH_SESSION_VARIABLES,
  SCH_STATISTICS,
  SCH_STATUS,
  SCH_TABLES,
  SCH_TABLESPACES,
  SCH_TABLE_CONSTRAINTS,
  SCH_TABLE_NAMES,
  SCH_TABLE_PRIVILEGES,
  SCH_TABLE_STATS,
  SCH_TEMPORARY_TABLES,
  SCH_THREAD_STATS,
  SCH_TRIGGERS,
  SCH_USER_PRIVILEGES,
  SCH_USER_STATS,
  SCH_VARIABLES,
  SCH_VIEWS
};


class handler;
/*
  handlerton is a singleton structure - one instance per storage engine -
  to provide access to storage engine functionality that works on the
  "global" level (unlike handler class that works on a per-table basis)

  usually handlerton instance is defined statically in ha_xxx.cc as

  static handlerton { ... } xxx_hton;

  savepoint_*, prepare, recover, and *_by_xid pointers can be 0.
*/
struct handlerton
{
  /*
    Historical number used for frm file to determine the correct storage engine.
    This is going away and new engines will just use "name" for this.
  */
  enum legacy_db_type db_type;
  /*
    each storage engine has it's own memory area (actually a pointer)
    in the thd, for storing per-connection information.
    It is accessed as

      thd->ha_data[xxx_hton.slot]

   slot number is initialized by MySQL after xxx_init() is called.
   */
   uint slot;
   /*
     to store per-savepoint data storage engine is provided with an area
     of a requested size (0 is ok here).
     savepoint_offset must be initialized statically to the size of
     the needed memory to store per-savepoint information.
     After xxx_init it is changed to be an offset to savepoint storage
     area and need not be used by storage engine.
     see binlog_hton and binlog_savepoint_set/rollback for an example.
   */
   uint savepoint_offset;


   uint32 flags;                                /* global handler flags */

   uint32 license; /* Flag for Engine License */
   void *data; /* Location for engines to keep personal structures */
};

/* In which table to INSERT rows */
#define MERGE_INSERT_DISABLED	0
#define MERGE_INSERT_TO_FIRST	1
#define MERGE_INSERT_TO_LAST	2

/* Possible flags of a handlerton (there can be 32 of them) */
#define HTON_NO_FLAGS                 0
#define HTON_CLOSE_CURSORS_AT_COMMIT (1 << 0)
#define HTON_ALTER_NOT_SUPPORTED     (1 << 1) //Engine does not support alter
#define HTON_CAN_RECREATE            (1 << 2) //Delete all is used fro truncate
#define HTON_HIDDEN                  (1 << 3) //Engine does not appear in lists
#define HTON_FLUSH_AFTER_RENAME      (1 << 4)
#define HTON_NOT_USER_SELECTABLE     (1 << 5)
#define HTON_TEMPORARY_NOT_SUPPORTED (1 << 6) //Having temporary tables not supported
#define HTON_SUPPORT_LOG_TABLES      (1 << 7) //Engine supports log tables
#define HTON_NO_PARTITION            (1 << 8) //You can not partition these tables

typedef struct {
  ulonglong data_file_length;
  ulonglong max_data_file_length;
  ulonglong index_file_length;
  ulonglong delete_length;
  ha_rows records;
  ulong mean_rec_length;
  ulong create_time;
  ulong check_time;
  ulong update_time;
  ulonglong check_sum;
} PARTITION_STATS;

#define UNDEF_NODEGROUP 65535
class Item;
struct st_table_log_memory_entry;

class partition_info;

struct st_partition_iter;

enum enum_ha_unused { HA_CHOICE_UNDEF, HA_CHOICE_NO, HA_CHOICE_YES };

enum enum_stats_auto_recalc { HA_STATS_AUTO_RECALC_DEFAULT= 0,
                              HA_STATS_AUTO_RECALC_ON,
                              HA_STATS_AUTO_RECALC_OFF };

typedef struct st_ha_create_information
{
  const CHARSET_INFO *table_charset, *default_table_charset;
  LEX_STRING connect_string;
  const char *password, *tablespace;
  LEX_STRING comment;
  const char *data_file_name, *index_file_name;
  const char *alias;
  ulonglong max_rows,min_rows;
  ulonglong auto_increment_value;
  ulong table_options;
  ulong avg_row_length;
  ulong used_fields;
  ulong key_block_size;
  uint stats_sample_pages;		/* number of pages to sample during
					stats estimation, if used, otherwise 0. */
  enum_stats_auto_recalc stats_auto_recalc;
  SQL_I_List<TABLE_LIST> merge_list;
  handlerton *db_type;
  /**
    Row type of the table definition.

    Defaults to ROW_TYPE_DEFAULT for all non-ALTER statements.
    For ALTER TABLE defaults to ROW_TYPE_NOT_USED (means "keep the current").

    Can be changed either explicitly by the parser.
    If nothing speficied inherits the value of the original table (if present).
  */
  enum row_type row_type;
  uint null_bits;                       /* NULL bits at start of record */
  uint options;				/* OR of HA_CREATE_ options */
  uint merge_insert_method;
  uint extra_size;                      /* length of extra data segment */
  bool varchar;                         /* 1 if table has a VARCHAR */
  enum ha_storage_media storage_media;  /* DEFAULT, DISK or MEMORY */
} HA_CREATE_INFO;


typedef struct st_key_create_information
{
  enum ha_key_alg algorithm;
  ulong block_size;
  LEX_STRING parser_name;
  LEX_STRING comment;
  /**
    A flag to determine if we will check for duplicate indexes.
    This typically means that the key information was specified
    directly by the user (set by the parser) or a column
    associated with it was dropped.
  */
  bool check_for_duplicate_indexes;
} KEY_CREATE_INFO;




extern KEY_CREATE_INFO default_key_create_info;

typedef struct st_ha_check_opt
{
  st_ha_check_opt() {}                        /* Remove gcc warning */
  uint flags;       /* isam layer flags (e.g. for myisamchk) */
  uint sql_flags;   /* sql layer flags - for something myisamchk cannot do */
  void init()
  {
    flags= sql_flags= 0;
  }
} HA_CHECK_OPT;

#endif /* HANDLER_INCLUDED */