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mariadb/sql/handler.h

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#ifndef HANDLER_INCLUDED
#define HANDLER_INCLUDED
/*
Copyright (c) 2000, 2014, Oracle and/or its affiliates.
Copyright (c) 2009, 2014, Monty Program 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; 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 */
#ifdef USE_PRAGMA_INTERFACE
#pragma interface /* gcc class implementation */
#endif
#include "sql_const.h"
#include "mysqld.h" /* server_id */
#include "sql_plugin.h" /* plugin_ref, st_plugin_int, plugin */
#include "thr_lock.h" /* thr_lock_type, THR_LOCK_DATA */
#include "sql_cache.h"
#include "structs.h" /* SHOW_COMP_OPTION */
#include "sql_array.h" /* Dynamic_array<> */
#include "mdl.h"
#include "sql_analyze_stmt.h" // for Exec_time_tracker
#include <my_compare.h>
#include <ft_global.h>
#include <keycache.h>
#include <mysql/psi/mysql_table.h>
#if MAX_KEY > 128
#error MAX_KEY is too large. Values up to 128 are supported.
#endif
class Alter_info;
// the following is for checking tables
#define HA_ADMIN_ALREADY_DONE 1
#define HA_ADMIN_OK 0
#define HA_ADMIN_NOT_IMPLEMENTED -1
#define HA_ADMIN_FAILED -2
#define HA_ADMIN_CORRUPT -3
#define HA_ADMIN_INTERNAL_ERROR -4
#define HA_ADMIN_INVALID -5
#define HA_ADMIN_REJECT -6
#define HA_ADMIN_TRY_ALTER -7
#define HA_ADMIN_WRONG_CHECKSUM -8
#define HA_ADMIN_NOT_BASE_TABLE -9
#define HA_ADMIN_NEEDS_UPGRADE -10
#define HA_ADMIN_NEEDS_ALTER -11
#define HA_ADMIN_NEEDS_CHECK -12
/**
Return values for check_if_supported_inplace_alter().
@see check_if_supported_inplace_alter() for description of
the individual values.
*/
enum enum_alter_inplace_result {
HA_ALTER_ERROR,
HA_ALTER_INPLACE_NOT_SUPPORTED,
HA_ALTER_INPLACE_EXCLUSIVE_LOCK,
HA_ALTER_INPLACE_SHARED_LOCK_AFTER_PREPARE,
HA_ALTER_INPLACE_SHARED_LOCK,
HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE,
HA_ALTER_INPLACE_NO_LOCK
};
/* Bits in table_flags() to show what database can do */
#define HA_NO_TRANSACTIONS (1ULL << 0) /* Doesn't support transactions */
#define HA_PARTIAL_COLUMN_READ (1ULL << 1) /* read may not return all columns */
#define HA_TABLE_SCAN_ON_INDEX (1ULL << 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 (1ULL << 3)
#define HA_CAN_GEOMETRY (1ULL << 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 (1ULL << 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 (1ULL << 6)
#define HA_NULL_IN_KEY (1ULL << 7) /* One can have keys with NULL */
#define HA_DUPLICATE_POS (1ULL << 8) /* ha_position() gives dup row */
#define HA_NO_BLOBS (1ULL << 9) /* Doesn't support blobs */
#define HA_CAN_INDEX_BLOBS (1ULL << 10)
#define HA_AUTO_PART_KEY (1ULL << 11) /* auto-increment in multi-part key */
#define HA_REQUIRE_PRIMARY_KEY (1ULL << 12) /* .. and can't create a hidden one */
#define HA_STATS_RECORDS_IS_EXACT (1ULL << 13) /* stats.records is exact */
/*
INSERT_DELAYED only works with handlers that uses MySQL internal table
level locks
*/
#define HA_CAN_INSERT_DELAYED (1ULL << 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 (1ULL << 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 (1ULL << 16)
#define HA_CAN_RTREEKEYS (1ULL << 17)
#define HA_NOT_DELETE_WITH_CACHE (1ULL << 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 (1ULL << 19)
#define HA_NO_PREFIX_CHAR_KEYS (1ULL << 20)
#define HA_CAN_FULLTEXT (1ULL << 21)
#define HA_CAN_SQL_HANDLER (1ULL << 22)
#define HA_NO_AUTO_INCREMENT (1ULL << 23)
/* Has automatic checksums and uses the old checksum format */
#define HA_HAS_OLD_CHECKSUM (1ULL << 24)
/* Table data are stored in separate files (for lower_case_table_names) */
#define HA_FILE_BASED (1ULL << 26)
#define HA_NO_VARCHAR (1ULL << 27)
#define HA_CAN_BIT_FIELD (1ULL << 28) /* supports bit fields */
#define HA_NEED_READ_RANGE_BUFFER (1ULL << 29) /* for read_multi_range */
#define HA_ANY_INDEX_MAY_BE_UNIQUE (1ULL << 30)
#define HA_NO_COPY_ON_ALTER (1ULL << 31)
#define HA_HAS_RECORDS (1ULL << 32) /* records() gives exact count*/
/* Has it's own method of binlog logging */
#define HA_HAS_OWN_BINLOGGING (1ULL << 33)
/*
Engine is capable of row-format and statement-format logging,
respectively
*/
#define HA_BINLOG_ROW_CAPABLE (1ULL << 34)
#define HA_BINLOG_STMT_CAPABLE (1ULL << 35)
/*
When a multiple key conflict happens in a REPLACE command mysql
expects the conflicts to be reported in the ascending order of
key names.
For e.g.
CREATE TABLE t1 (a INT, UNIQUE (a), b INT NOT NULL, UNIQUE (b), c INT NOT
NULL, INDEX(c));
REPLACE INTO t1 VALUES (1,1,1),(2,2,2),(2,1,3);
MySQL expects the conflict with 'a' to be reported before the conflict with
'b'.
If the underlying storage engine does not report the conflicting keys in
ascending order, it causes unexpected errors when the REPLACE command is
executed.
This flag helps the underlying SE to inform the server that the keys are not
ordered.
*/
#define HA_DUPLICATE_KEY_NOT_IN_ORDER (1ULL << 36)
/*
Engine supports REPAIR TABLE. Used by CHECK TABLE FOR UPGRADE if an
incompatible table is detected. If this flag is set, CHECK TABLE FOR UPGRADE
will report ER_TABLE_NEEDS_UPGRADE, otherwise ER_TABLE_NEED_REBUILD.
*/
#define HA_CAN_REPAIR (1ULL << 37)
/* Has automatic checksums and uses the new checksum format */
#define HA_HAS_NEW_CHECKSUM (1ULL << 38)
#define HA_CAN_VIRTUAL_COLUMNS (1ULL << 39)
#define HA_MRR_CANT_SORT (1ULL << 40)
#define HA_RECORD_MUST_BE_CLEAN_ON_WRITE (1ULL << 41)
/*
This storage engine supports condition pushdown
*/
#define HA_CAN_TABLE_CONDITION_PUSHDOWN (1ULL << 42)
/* old name for the same flag */
#define HA_MUST_USE_TABLE_CONDITION_PUSHDOWN HA_CAN_TABLE_CONDITION_PUSHDOWN
/**
The handler supports read before write removal optimization
Read before write removal may be used for storage engines which support
write without previous read of the row to be updated. Handler returning
this flag must implement start_read_removal() and end_read_removal().
The handler may return "fake" rows constructed from the key of the row
asked for. This is used to optimize UPDATE and DELETE by reducing the
numer of roundtrips between handler and storage engine.
Example:
UPDATE a=1 WHERE pk IN (<keys>)
mysql_update()
{
if (<conditions for starting read removal>)
start_read_removal()
-> handler returns true if read removal supported for this table/query
while(read_record("pk=<key>"))
-> handler returns fake row with column "pk" set to <key>
ha_update_row()
-> handler sends write "a=1" for row with "pk=<key>"
end_read_removal()
-> handler returns the number of rows actually written
}
@note This optimization in combination with batching may be used to
remove even more roundtrips.
*/
#define HA_READ_BEFORE_WRITE_REMOVAL (1LL << 43)
/*
Engine supports extended fulltext API
*/
#define HA_CAN_FULLTEXT_EXT (1LL << 44)
/*
Storage engine supports table export using the
FLUSH TABLE <table_list> FOR EXPORT statement
(meaning, after this statement one can copy table files out of the
datadir and later "import" (somehow) in another MariaDB instance)
*/
#define HA_CAN_EXPORT (1LL << 45)
/*
Set of all binlog flags. Currently only contain the capabilities
flags.
*/
#define HA_BINLOG_FLAGS (HA_BINLOG_ROW_CAPABLE | HA_BINLOG_STMT_CAPABLE)
/* bits in index_flags(index_number) for what you can do with index */
#define HA_READ_NEXT 1 /* TODO really use this flag */
#define HA_READ_PREV 2 /* supports ::index_prev */
#define HA_READ_ORDER 4 /* index_next/prev follow sort order */
#define HA_READ_RANGE 8 /* can find all records in a range */
#define HA_ONLY_WHOLE_INDEX 16 /* Can't use part key searches */
#define HA_KEYREAD_ONLY 64 /* Support HA_EXTRA_KEYREAD */
/*
Index scan will not return records in rowid order. Not guaranteed to be
set for unordered (e.g. HASH) indexes.
*/
#define HA_KEY_SCAN_NOT_ROR 128
#define HA_DO_INDEX_COND_PUSHDOWN 256 /* Supports Index Condition Pushdown */
/*
Data is clustered on this key. This means that when you read the key
you also get the row data without any additional disk reads.
*/
#define HA_CLUSTERED_INDEX 512
/*
bits in alter_table_flags:
*/
/*
These bits are set if different kinds of indexes can be created or dropped
in-place without re-creating the table using a temporary table.
NO_READ_WRITE indicates that the handler needs concurrent reads and writes
of table data to be blocked.
Partitioning needs both ADD and DROP to be supported by its underlying
handlers, due to error handling, see bug#57778.
*/
#define HA_INPLACE_ADD_INDEX_NO_READ_WRITE (1L << 0)
#define HA_INPLACE_DROP_INDEX_NO_READ_WRITE (1L << 1)
#define HA_INPLACE_ADD_UNIQUE_INDEX_NO_READ_WRITE (1L << 2)
#define HA_INPLACE_DROP_UNIQUE_INDEX_NO_READ_WRITE (1L << 3)
#define HA_INPLACE_ADD_PK_INDEX_NO_READ_WRITE (1L << 4)
#define HA_INPLACE_DROP_PK_INDEX_NO_READ_WRITE (1L << 5)
/*
These are set if different kinds of indexes can be created or dropped
in-place while still allowing concurrent reads (but not writes) of table
data. If a handler is capable of one or more of these, it should also set
the corresponding *_NO_READ_WRITE bit(s).
*/
#define HA_INPLACE_ADD_INDEX_NO_WRITE (1L << 6)
#define HA_INPLACE_DROP_INDEX_NO_WRITE (1L << 7)
#define HA_INPLACE_ADD_UNIQUE_INDEX_NO_WRITE (1L << 8)
#define HA_INPLACE_DROP_UNIQUE_INDEX_NO_WRITE (1L << 9)
#define HA_INPLACE_ADD_PK_INDEX_NO_WRITE (1L << 10)
#define HA_INPLACE_DROP_PK_INDEX_NO_WRITE (1L << 11)
/*
HA_PARTITION_FUNCTION_SUPPORTED indicates that the function is
supported at all.
HA_FAST_CHANGE_PARTITION means that optimised variants of the changes
exists but they are not necessarily done online.
HA_ONLINE_DOUBLE_WRITE means that the handler supports writing to both
the new partition and to the old partitions when updating through the
old partitioning schema while performing a change of the partitioning.
This means that we can support updating of the table while performing
the copy phase of the change. For no lock at all also a double write
from new to old must exist and this is not required when this flag is
set.
This is actually removed even before it was introduced the first time.
The new idea is that handlers will handle the lock level already in
store_lock for ALTER TABLE partitions.
HA_PARTITION_ONE_PHASE is a flag that can be set by handlers that take
care of changing the partitions online and in one phase. Thus all phases
needed to handle the change are implemented inside the storage engine.
The storage engine must also support auto-discovery since the frm file
is changed as part of the change and this change must be controlled by
the storage engine. A typical engine to support this is NDB (through
WL #2498).
*/
#define HA_PARTITION_FUNCTION_SUPPORTED (1L << 12)
#define HA_FAST_CHANGE_PARTITION (1L << 13)
#define HA_PARTITION_ONE_PHASE (1L << 14)
/* operations for disable/enable indexes */
#define HA_KEY_SWITCH_NONUNIQ 0
#define HA_KEY_SWITCH_ALL 1
#define HA_KEY_SWITCH_NONUNIQ_SAVE 2
#define HA_KEY_SWITCH_ALL_SAVE 3
/*
Note: the following includes binlog and closing 0.
TODO remove the limit, use dynarrays
*/
#define MAX_HA 64
/*
Use this instead of 0 as the initial value for the slot number of
handlerton, so that we can distinguish uninitialized slot number
from slot 0.
*/
#define HA_SLOT_UNDEF ((uint)-1)
/*
Parameters for open() (in register form->filestat)
HA_GET_INFO does an implicit HA_ABORT_IF_LOCKED
*/
#define HA_OPEN_KEYFILE 1
#define HA_OPEN_RNDFILE 2
#define HA_GET_INDEX 4
#define HA_GET_INFO 8 /* do a ha_info() after open */
#define HA_READ_ONLY 16 /* File opened as readonly */
/* Try readonly if can't open with read and write */
#define HA_TRY_READ_ONLY 32
#define HA_WAIT_IF_LOCKED 64 /* Wait if locked on open */
#define HA_ABORT_IF_LOCKED 128 /* skip if locked on open.*/
#define HA_BLOCK_LOCK 256 /* unlock when reading some records */
#define HA_OPEN_TEMPORARY 512
/* Some key definitions */
#define HA_KEY_NULL_LENGTH 1
#define HA_KEY_BLOB_LENGTH 2
#define HA_LEX_CREATE_TMP_TABLE 1
#define HA_CREATE_TMP_ALTER 8
#define HA_MAX_REC_LENGTH 65535
/* Table caching type */
#define HA_CACHE_TBL_NONTRANSACT 0
#define HA_CACHE_TBL_NOCACHE 1
#define HA_CACHE_TBL_ASKTRANSACT 2
#define HA_CACHE_TBL_TRANSACT 4
/**
Options for the START TRANSACTION statement.
Note that READ ONLY and READ WRITE are logically mutually exclusive.
This is enforced by the parser and depended upon by trans_begin().
We need two flags instead of one in order to differentiate between
situation when no READ WRITE/ONLY clause were given and thus transaction
is implicitly READ WRITE and the case when READ WRITE clause was used
explicitly.
*/
// 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;
/* Flags for method is_fatal_error */
#define HA_CHECK_DUP_KEY 1
#define HA_CHECK_DUP_UNIQUE 2
#define HA_CHECK_DUP (HA_CHECK_DUP_KEY + HA_CHECK_DUP_UNIQUE)
enum legacy_db_type
{
/* note these numerical values are fixed and can *not* be changed */
DB_TYPE_UNKNOWN=0,
DB_TYPE_HEAP=6,
DB_TYPE_MYISAM=9,
DB_TYPE_MRG_MYISAM=10,
DB_TYPE_INNODB=12,
DB_TYPE_EXAMPLE_DB=15,
DB_TYPE_ARCHIVE_DB=16,
DB_TYPE_CSV_DB=17,
DB_TYPE_FEDERATED_DB=18,
DB_TYPE_BLACKHOLE_DB=19,
DB_TYPE_PARTITION_DB=20,
DB_TYPE_BINLOG=21,
DB_TYPE_PBXT=23,
DB_TYPE_PERFORMANCE_SCHEMA=28,
DB_TYPE_ARIA=42,
DB_TYPE_TOKUDB=43,
DB_TYPE_FIRST_DYNAMIC=44,
DB_TYPE_DEFAULT=127 // Must be last
};
/*
Better name for DB_TYPE_UNKNOWN. Should be used for engines that do not have
a hard-coded type value here.
*/
#define DB_TYPE_AUTOASSIGN DB_TYPE_UNKNOWN
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, ROW_TYPE_PAGE };
/* not part of the enum, so that it shouldn't be in switch(row_type) */
#define ROW_TYPE_MAX ((uint)ROW_TYPE_PAGE + 1)
/* 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 */
};
enum enum_binlog_func {
BFN_RESET_LOGS= 1,
BFN_RESET_SLAVE= 2,
BFN_BINLOG_WAIT= 3,
BFN_BINLOG_END= 4,
BFN_BINLOG_PURGE_FILE= 5
};
enum enum_binlog_command {
LOGCOM_CREATE_TABLE,
LOGCOM_ALTER_TABLE,
LOGCOM_RENAME_TABLE,
LOGCOM_DROP_TABLE,
LOGCOM_CREATE_DB,
LOGCOM_ALTER_DB,
LOGCOM_DROP_DB
};
/* 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)
/* The following two are used by Maria engine: */
#define HA_CREATE_USED_TRANSACTIONAL (1L << 20)
#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)
/*
This is master database for most of system tables. However there
can be other databases which can hold system tables. Respective
storage engines define their own system database names.
*/
extern const char *mysqld_system_database;
/*
Structure to hold list of system_database.system_table.
This is used at both mysqld and storage engine layer.
*/
struct st_system_tablename
{
const char *db;
const char *tablename;
};
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+sizeof(server_id))
#define MYSQL_XID_GTRID_LEN (MYSQL_XID_OFFSET+sizeof(my_xid))
#define XIDDATASIZE MYSQL_XIDDATASIZE
#define MAXGTRIDSIZE 64
#define MAXBQUALSIZE 64
#define COMPATIBLE_DATA_YES 0
#define COMPATIBLE_DATA_NO 1
/**
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);
memcpy(data+MYSQL_XID_PREFIX_LEN, &server_id, sizeof(server_id));
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() const
{
return (uchar *)&gtrid_length;
}
uint key_length() const
{
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;
}
};
/* The handler for a table type. Will be included in the TABLE structure */
struct TABLE;
/*
Make sure that the order of schema_tables and enum_schema_tables are the same.
*/
enum enum_schema_tables
{
SCH_ALL_PLUGINS,
SCH_APPLICABLE_ROLES,
SCH_CHARSETS,
SCH_COLLATIONS,
SCH_COLLATION_CHARACTER_SET_APPLICABILITY,
SCH_COLUMNS,
SCH_COLUMN_PRIVILEGES,
SCH_ENABLED_ROLES,
SCH_ENGINES,
SCH_EVENTS,
SCH_EXPLAIN,
SCH_FILES,
SCH_GLOBAL_STATUS,
SCH_GLOBAL_VARIABLES,
SCH_KEY_CACHES,
SCH_KEY_COLUMN_USAGE,
SCH_OPEN_TABLES,
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_SYSTEM_VARIABLES,
SCH_TABLES,
SCH_TABLESPACES,
SCH_TABLE_CONSTRAINTS,
SCH_TABLE_NAMES,
SCH_TABLE_PRIVILEGES,
SCH_TRIGGERS,
SCH_USER_PRIVILEGES,
SCH_VIEWS,
#ifdef HAVE_SPATIAL
SCH_GEOMETRY_COLUMNS,
SCH_SPATIAL_REF_SYS,
#endif /*HAVE_SPATIAL*/
};
struct TABLE_SHARE;
struct HA_CREATE_INFO;
struct st_foreign_key_info;
typedef struct st_foreign_key_info FOREIGN_KEY_INFO;
typedef bool (stat_print_fn)(THD *thd, const char *type, uint type_len,
const char *file, uint file_len,
const char *status, uint status_len);
enum ha_stat_type { HA_ENGINE_STATUS, HA_ENGINE_LOGS, HA_ENGINE_MUTEX };
extern st_plugin_int *hton2plugin[MAX_HA];
/* Transaction log maintains type definitions */
enum log_status
{
HA_LOG_STATUS_FREE= 0, /* log is free and can be deleted */
HA_LOG_STATUS_INUSE= 1, /* log can't be deleted because it is in use */
HA_LOG_STATUS_NOSUCHLOG= 2 /* no such log (can't be returned by
the log iterator status) */
};
/*
Function for signaling that the log file changed its state from
LOG_STATUS_INUSE to LOG_STATUS_FREE
Now it do nothing, will be implemented as part of new transaction
log management for engines.
TODO: implement the function.
*/
void signal_log_not_needed(struct handlerton, char *log_file);
/*
Data of transaction log iterator.
*/
struct handler_log_file_data {
LEX_STRING filename;
enum log_status status;
};
/*
Definitions for engine-specific table/field/index options in the CREATE TABLE.
Options are declared with HA_*OPTION_* macros (HA_TOPTION_NUMBER,
HA_FOPTION_ENUM, HA_IOPTION_STRING, etc).
Every macros takes the option name, and the name of the underlying field of
the appropriate C structure. The "appropriate C structure" is
ha_table_option_struct for table level options,
ha_field_option_struct for field level options,
ha_index_option_struct for key level options. The engine either
defines a structure of this name, or uses #define's to map
these "appropriate" names to the actual structure type name.
ULL options use a ulonglong as the backing store.
HA_*OPTION_NUMBER() takes the option name, the structure field name,
the default value for the option, min, max, and blk_siz values.
STRING options use a char* as a backing store.
HA_*OPTION_STRING takes the option name and the structure field name.
The default value will be 0.
ENUM options use a uint as a backing store (not enum!!!).
HA_*OPTION_ENUM takes the option name, the structure field name,
the default value for the option as a number, and a string with the
permitted values for this enum - one string with comma separated values,
for example: "gzip,bzip2,lzma"
BOOL options use a bool as a backing store.
HA_*OPTION_BOOL takes the option name, the structure field name,
and the default value for the option.
From the SQL, BOOL options accept YES/NO, ON/OFF, and 1/0.
The name of the option is limited to 255 bytes,
the value (for string options) - to the 32767 bytes.
See ha_example.cc for an example.
*/
struct ha_table_option_struct;
struct ha_field_option_struct;
struct ha_index_option_struct;
enum ha_option_type { HA_OPTION_TYPE_ULL, /* unsigned long long */
HA_OPTION_TYPE_STRING, /* char * */
HA_OPTION_TYPE_ENUM, /* uint */
HA_OPTION_TYPE_BOOL, /* bool */
HA_OPTION_TYPE_SYSVAR};/* type of the sysval */
#define HA_xOPTION_NUMBER(name, struc, field, def, min, max, blk_siz) \
{ HA_OPTION_TYPE_ULL, name, sizeof(name)-1, \
offsetof(struc, field), def, min, max, blk_siz, 0, 0 }
#define HA_xOPTION_STRING(name, struc, field) \
{ HA_OPTION_TYPE_STRING, name, sizeof(name)-1, \
offsetof(struc, field), 0, 0, 0, 0, 0, 0}
#define HA_xOPTION_ENUM(name, struc, field, values, def) \
{ HA_OPTION_TYPE_ENUM, name, sizeof(name)-1, \
offsetof(struc, field), def, 0, \
sizeof(values)-1, 0, values, 0 }
#define HA_xOPTION_BOOL(name, struc, field, def) \
{ HA_OPTION_TYPE_BOOL, name, sizeof(name)-1, \
offsetof(struc, field), def, 0, 1, 0, 0, 0 }
#define HA_xOPTION_SYSVAR(name, struc, field, sysvar) \
{ HA_OPTION_TYPE_SYSVAR, name, sizeof(name)-1, \
offsetof(struc, field), 0, 0, 0, 0, 0, MYSQL_SYSVAR(sysvar) }
#define HA_xOPTION_END { HA_OPTION_TYPE_ULL, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
#define HA_TOPTION_NUMBER(name, field, def, min, max, blk_siz) \
HA_xOPTION_NUMBER(name, ha_table_option_struct, field, def, min, max, blk_siz)
#define HA_TOPTION_STRING(name, field) \
HA_xOPTION_STRING(name, ha_table_option_struct, field)
#define HA_TOPTION_ENUM(name, field, values, def) \
HA_xOPTION_ENUM(name, ha_table_option_struct, field, values, def)
#define HA_TOPTION_BOOL(name, field, def) \
HA_xOPTION_BOOL(name, ha_table_option_struct, field, def)
#define HA_TOPTION_SYSVAR(name, field, sysvar) \
HA_xOPTION_SYSVAR(name, ha_table_option_struct, field, sysvar)
#define HA_TOPTION_END HA_xOPTION_END
#define HA_FOPTION_NUMBER(name, field, def, min, max, blk_siz) \
HA_xOPTION_NUMBER(name, ha_field_option_struct, field, def, min, max, blk_siz)
#define HA_FOPTION_STRING(name, field) \
HA_xOPTION_STRING(name, ha_field_option_struct, field)
#define HA_FOPTION_ENUM(name, field, values, def) \
HA_xOPTION_ENUM(name, ha_field_option_struct, field, values, def)
#define HA_FOPTION_BOOL(name, field, def) \
HA_xOPTION_BOOL(name, ha_field_option_struct, field, def)
#define HA_FOPTION_SYSVAR(name, field, sysvar) \
HA_xOPTION_SYSVAR(name, ha_field_option_struct, field, sysvar)
#define HA_FOPTION_END HA_xOPTION_END
#define HA_IOPTION_NUMBER(name, field, def, min, max, blk_siz) \
HA_xOPTION_NUMBER(name, ha_index_option_struct, field, def, min, max, blk_siz)
#define HA_IOPTION_STRING(name, field) \
HA_xOPTION_STRING(name, ha_index_option_struct, field)
#define HA_IOPTION_ENUM(name, field, values, def) \
HA_xOPTION_ENUM(name, ha_index_option_struct, field, values, def)
#define HA_IOPTION_BOOL(name, field, def) \
HA_xOPTION_BOOL(name, ha_index_option_struct, field, def)
#define HA_IOPTION_SYSVAR(name, field, sysvar) \
HA_xOPTION_SYSVAR(name, ha_index_option_struct, field, sysvar)
#define HA_IOPTION_END HA_xOPTION_END
typedef struct st_ha_create_table_option {
enum ha_option_type type;
const char *name;
size_t name_length;
ptrdiff_t offset;
ulonglong def_value;
ulonglong min_value, max_value, block_size;
const char *values;
struct st_mysql_sys_var *var;
} ha_create_table_option;
enum handler_iterator_type
{
/* request of transaction log iterator */
HA_TRANSACTLOG_ITERATOR= 1
};
enum handler_create_iterator_result
{
HA_ITERATOR_OK, /* iterator created */
HA_ITERATOR_UNSUPPORTED, /* such type of iterator is not supported */
HA_ITERATOR_ERROR /* error during iterator creation */
};
/*
Iterator structure. Can be used by handler/handlerton for different purposes.
Iterator should be created in the way to point "before" the first object
it iterate, so next() call move it to the first object or return !=0 if
there is nothing to iterate through.
*/
struct handler_iterator {
/*
Moves iterator to next record and return 0 or return !=0
if there is no records.
iterator_object will be filled by this function if next() returns 0.
Content of the iterator_object depend on iterator type.
*/
int (*next)(struct handler_iterator *, void *iterator_object);
/*
Free resources allocated by iterator, after this call iterator
is not usable.
*/
void (*destroy)(struct handler_iterator *);
/*
Pointer to buffer for the iterator to use.
Should be allocated by function which created the iterator and
destroied by freed by above "destroy" call
*/
void *buffer;
};
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 marker for if the engine is available of not
*/
SHOW_COMP_OPTION state;
/*
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;
/*
handlerton methods:
close_connection is only called if
thd->ha_data[xxx_hton.slot] is non-zero, so even if you don't need
this storage area - set it to something, so that MySQL would know
this storage engine was accessed in this connection
*/
int (*close_connection)(handlerton *hton, THD *thd);
/*
Tell handler that query has been killed.
*/
void (*kill_query)(handlerton *hton, THD *thd, enum thd_kill_levels level);
/*
sv points to an uninitialized storage area of requested size
(see savepoint_offset description)
*/
int (*savepoint_set)(handlerton *hton, THD *thd, void *sv);
/*
sv points to a storage area, that was earlier passed
to the savepoint_set call
*/
int (*savepoint_rollback)(handlerton *hton, THD *thd, void *sv);
/**
Check if storage engine allows to release metadata locks which were
acquired after the savepoint if rollback to savepoint is done.
@return true - If it is safe to release MDL locks.
false - If it is not.
*/
bool (*savepoint_rollback_can_release_mdl)(handlerton *hton, THD *thd);
int (*savepoint_release)(handlerton *hton, THD *thd, void *sv);
/*
'all' is true if it's a real commit, that makes persistent changes
'all' is false if it's not in fact a commit but an end of the
statement that is part of the transaction.
NOTE 'all' is also false in auto-commit mode where 'end of statement'
and 'real commit' mean the same event.
*/
int (*commit)(handlerton *hton, THD *thd, bool all);
/*
The commit_ordered() method is called prior to the commit() method, after
the transaction manager has decided to commit (not rollback) the
transaction. Unlike commit(), commit_ordered() is called only when the
full transaction is committed, not for each commit of statement
transaction in a multi-statement transaction.
Not that like prepare(), commit_ordered() is only called when 2-phase
commit takes place. Ie. when no binary log and only a single engine
participates in a transaction, one commit() is called, no
commit_ordered(). So engines must be prepared for this.
The calls to commit_ordered() in multiple parallel transactions is
guaranteed to happen in the same order in every participating
handler. This can be used to ensure the same commit order among multiple
handlers (eg. in table handler and binlog). So if transaction T1 calls
into commit_ordered() of handler A before T2, then T1 will also call
commit_ordered() of handler B before T2.
Engines that implement this method should during this call make the
transaction visible to other transactions, thereby making the order of
transaction commits be defined by the order of commit_ordered() calls.
The intention is that commit_ordered() should do the minimal amount of
work that needs to happen in consistent commit order among handlers. To
preserve ordering, calls need to be serialised on a global mutex, so
doing any time-consuming or blocking operations in commit_ordered() will
limit scalability.
Handlers can rely on commit_ordered() calls to be serialised (no two
calls can run in parallel, so no extra locking on the handler part is
required to ensure this).
Note that commit_ordered() can be called from a different thread than the
one handling the transaction! So it can not do anything that depends on
thread local storage, in particular it can not call my_error() and
friends (instead it can store the error code and delay the call of
my_error() to the commit() method).
Similarly, since commit_ordered() returns void, any return error code
must be saved and returned from the commit() method instead.
The commit_ordered method is optional, and can be left unset if not
needed in a particular handler (then there will be no ordering guarantees
wrt. other engines and binary log).
*/
void (*commit_ordered)(handlerton *hton, THD *thd, bool all);
int (*rollback)(handlerton *hton, THD *thd, bool all);
int (*prepare)(handlerton *hton, THD *thd, bool all);
/*
The prepare_ordered method is optional. If set, it will be called after
successful prepare() in all handlers participating in 2-phase
commit. Like commit_ordered(), it is called only when the full
transaction is committed, not for each commit of statement transaction.
The calls to prepare_ordered() among multiple parallel transactions are
ordered consistently with calls to commit_ordered(). This means that
calls to prepare_ordered() effectively define the commit order, and that
each handler will see the same sequence of transactions calling into
prepare_ordered() and commit_ordered().
Thus, prepare_ordered() can be used to define commit order for handlers
that need to do this in the prepare step (like binlog). It can also be
used to release transaction's locks early in an order consistent with the
order transactions will be eventually committed.
Like commit_ordered(), prepare_ordered() calls are serialised to maintain
ordering, so the intention is that they should execute fast, with only
the minimal amount of work needed to define commit order. Handlers can
rely on this serialisation, and do not need to do any extra locking to
avoid two prepare_ordered() calls running in parallel.
Like commit_ordered(), prepare_ordered() is not guaranteed to be called
in the context of the thread handling the rest of the transaction. So it
cannot invoke code that relies on thread local storage, in particular it
cannot call my_error().
prepare_ordered() cannot cause a rollback by returning an error, all
possible errors must be handled in prepare() (the prepare_ordered()
method returns void). In case of some fatal error, a record of the error
must be made internally by the engine and returned from commit() later.
Note that for user-level XA SQL commands, no consistent ordering among
prepare_ordered() and commit_ordered() is guaranteed (as that would
require blocking all other commits for an indefinite time).
When 2-phase commit is not used (eg. only one engine (and no binlog) in
transaction), neither prepare() nor prepare_ordered() is called.
*/
void (*prepare_ordered)(handlerton *hton, THD *thd, bool all);
int (*recover)(handlerton *hton, XID *xid_list, uint len);
int (*commit_by_xid)(handlerton *hton, XID *xid);
int (*rollback_by_xid)(handlerton *hton, XID *xid);
/*
The commit_checkpoint_request() handlerton method is used to checkpoint
the XA recovery process for storage engines that support two-phase
commit.
The method is optional - an engine that does not implemented is expected
to work the traditional way, where every commit() durably flushes the
transaction to disk in the engine before completion, so XA recovery will
no longer be needed for that transaction.
An engine that does implement commit_checkpoint_request() is also
expected to implement commit_ordered(), so that ordering of commits is
consistent between 2pc participants. Such engine is no longer required to
durably flush to disk transactions in commit(), provided that the
transaction has been successfully prepare()d and commit_ordered(); thus
potentionally saving one fsync() call. (Engine must still durably flush
to disk in commit() when no prepare()/commit_ordered() steps took place,
at least if durable commits are wanted; this happens eg. if binlog is
disabled).
The TC will periodically (eg. once per binlog rotation) call
commit_checkpoint_request(). When this happens, the engine must arrange
for all transaction that have completed commit_ordered() to be durably
flushed to disk (this does not include transactions that might be in the
middle of executing commit_ordered()). When such flush has completed, the
engine must call commit_checkpoint_notify_ha(), passing back the opaque
"cookie".
The flush and call of commit_checkpoint_notify_ha() need not happen
immediately - it can be scheduled and performed asynchroneously (ie. as
part of next prepare(), or sync every second, or whatever), but should
not be postponed indefinitely. It is however also permissible to do it
immediately, before returning from commit_checkpoint_request().
When commit_checkpoint_notify_ha() is called, the TC will know that the
transactions are durably committed, and thus no longer require XA
recovery. It uses that to reduce the work needed for any subsequent XA
recovery process.
*/
void (*commit_checkpoint_request)(handlerton *hton, void *cookie);
/*
"Disable or enable checkpointing internal to the storage engine. This is
used for FLUSH TABLES WITH READ LOCK AND DISABLE CHECKPOINT to ensure that
the engine will never start any recovery from a time between
FLUSH TABLES ... ; UNLOCK TABLES.
While checkpointing is disabled, the engine should pause any background
write activity (such as tablespace checkpointing) that require consistency
between different files (such as transaction log and tablespace files) for
crash recovery to succeed. The idea is to use this to make safe
multi-volume LVM snapshot backups.
*/
int (*checkpoint_state)(handlerton *hton, bool disabled);
void *(*create_cursor_read_view)(handlerton *hton, THD *thd);
void (*set_cursor_read_view)(handlerton *hton, THD *thd, void *read_view);
void (*close_cursor_read_view)(handlerton *hton, THD *thd, void *read_view);
handler *(*create)(handlerton *hton, TABLE_SHARE *table, MEM_ROOT *mem_root);
void (*drop_database)(handlerton *hton, char* path);
int (*panic)(handlerton *hton, enum ha_panic_function flag);
int (*start_consistent_snapshot)(handlerton *hton, THD *thd);
bool (*flush_logs)(handlerton *hton);
bool (*show_status)(handlerton *hton, THD *thd, stat_print_fn *print, enum ha_stat_type stat);
uint (*partition_flags)();
uint (*alter_table_flags)(uint flags);
int (*alter_tablespace)(handlerton *hton, THD *thd, st_alter_tablespace *ts_info);
int (*fill_is_table)(handlerton *hton, THD *thd, TABLE_LIST *tables,
class Item *cond,
enum enum_schema_tables);
uint32 flags; /* global handler flags */
/*
Those handlerton functions below are properly initialized at handler
init.
*/
int (*binlog_func)(handlerton *hton, THD *thd, enum_binlog_func fn, void *arg);
void (*binlog_log_query)(handlerton *hton, THD *thd,
enum_binlog_command binlog_command,
const char *query, uint query_length,
const char *db, const char *table_name);
int (*release_temporary_latches)(handlerton *hton, THD *thd);
/*
Get log status.
If log_status is null then the handler do not support transaction
log information (i.e. log iterator can't be created).
(see example of implementation in handler.cc, TRANS_LOG_MGM_EXAMPLE_CODE)
*/
enum log_status (*get_log_status)(handlerton *hton, char *log);
/*
Iterators creator.
Presence of the pointer should be checked before using
*/
enum handler_create_iterator_result
(*create_iterator)(handlerton *hton, enum handler_iterator_type type,
struct handler_iterator *fill_this_in);
int (*abort_transaction)(handlerton *hton, THD *bf_thd,
THD *victim_thd, my_bool signal);
int (*set_checkpoint)(handlerton *hton, const XID* xid);
int (*get_checkpoint)(handlerton *hton, XID* xid);
void (*fake_trx_id)(handlerton *hton, THD *thd);
/*
Optional clauses in the CREATE/ALTER TABLE
*/
ha_create_table_option *table_options; // table level options
ha_create_table_option *field_options; // these are specified per field
ha_create_table_option *index_options; // these are specified per index
/**
The list of extensions of files created for a single table in the
database directory (datadir/db_name/).
Used by open_table_error(), by the default rename_table and delete_table
handler methods, and by the default discovery implementation.
For engines that have more than one file name extentions (separate
metadata, index, and/or data files), the order of elements is relevant.
First element of engine file name extentions array should be metadata
file extention. This is implied by the open_table_error()
and the default discovery implementation.
Second element - data file extention. This is implied
assumed by REPAIR TABLE ... USE_FRM implementation.
*/
const char **tablefile_extensions; // by default - empty list
/*********************************************************************
Table discovery API.
It allows the server to "discover" tables that exist in the storage
engine, without user issuing an explicit CREATE TABLE statement.
**********************************************************************/
/*
This method is required for any engine that supports automatic table
discovery, there is no default implementation.
Given a TABLE_SHARE discover_table() fills it in with a correct table
structure using one of the TABLE_SHARE::init_from_* methods.
Returns HA_ERR_NO_SUCH_TABLE if the table did not exist in the engine,
zero if the table was discovered successfully, or any other
HA_ERR_* error code as appropriate if the table existed, but the
discovery failed.
*/
int (*discover_table)(handlerton *hton, THD* thd, TABLE_SHARE *share);
/*
The discover_table_names method tells the server
about all tables in the specified database that the engine
knows about. Tables (or file names of tables) are added to
the provided discovered_list collector object using
add_table() or add_file() methods.
*/
class discovered_list
{
public:
virtual bool add_table(const char *tname, size_t tlen) = 0;
virtual bool add_file(const char *fname) = 0;
protected: virtual ~discovered_list() {}
};
/*
By default (if not implemented by the engine, but the discovery_table() is
implemented) it will perform a file-based discovery:
- if tablefile_extensions[0] is not null, this will discovers all tables
with the tablefile_extensions[0] extension.
Returns 0 on success and 1 on error.
*/
int (*discover_table_names)(handlerton *hton, LEX_STRING *db, MY_DIR *dir,
discovered_list *result);
/*
This is a method that allows to server to check if a table exists without
an overhead of the complete discovery.
By default (if not implemented by the engine, but the discovery_table() is
implemented) it will try to perform a file-based discovery:
- if tablefile_extensions[0] is not null this will look for a file name
with the tablefile_extensions[0] extension.
- if tablefile_extensions[0] is null, this will resort to discover_table().
Note that resorting to discover_table() is slow and the engine
should probably implement its own discover_table_existence() method,
if its tablefile_extensions[0] is null.
Returns 1 if the table exists and 0 if it does not.
*/
int (*discover_table_existence)(handlerton *hton, const char *db,
const char *table_name);
/*
This is the assisted table discovery method. Unlike the fully
automatic discovery as above, here a user is expected to issue an
explicit CREATE TABLE with the appropriate table attributes to
"assist" the discovery of a table. But this "discovering" CREATE TABLE
statement will not specify the table structure - the engine discovers
it using this method. For example, FederatedX uses it in
CREATE TABLE t1 ENGINE=FEDERATED CONNECTION="mysql://foo/bar/t1";
Given a TABLE_SHARE discover_table_structure() fills it in with a correct
table structure using one of the TABLE_SHARE::init_from_* methods.
Assisted discovery works independently from the automatic discover.
An engine is allowed to support only assisted discovery and not
support automatic one. Or vice versa.
*/
int (*discover_table_structure)(handlerton *hton, THD* thd,
TABLE_SHARE *share, HA_CREATE_INFO *info);
};
static inline LEX_STRING *hton_name(const handlerton *hton)
{
return &(hton2plugin[hton->slot]->name);
}
static inline handlerton *plugin_hton(plugin_ref plugin)
{
return plugin_data(plugin, handlerton *);
}
static inline sys_var *find_hton_sysvar(handlerton *hton, st_mysql_sys_var *var)
{
return find_plugin_sysvar(hton2plugin[hton->slot], var);
}
handlerton *ha_default_handlerton(THD *thd);
handlerton *ha_default_tmp_handlerton(THD *thd);
/* 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 for truncate
#define HTON_HIDDEN (1 << 3) //Engine does not appear in lists
#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) //Not partition of these tables
/*
This flag should be set when deciding that the engine does not allow
row based binary logging (RBL) optimizations.
Currently, setting this flag, means that table's read/write_set will
be left untouched when logging changes to tables in this engine. In
practice this means that the server will not mess around with
table->write_set and/or table->read_set when using RBL and deciding
whether to log full or minimal rows.
It's valuable for instance for virtual tables, eg: Performance
Schema which have no meaning for replication.
*/
#define HTON_NO_BINLOG_ROW_OPT (1 << 9)
#define HTON_SUPPORTS_EXTENDED_KEYS (1 <<10) //supports extended keys
// MySQL compatibility. Unused.
#define HTON_SUPPORTS_FOREIGN_KEYS (1 << 0) //Foreign key constraint supported.
class Ha_trx_info;
struct THD_TRANS
{
/* true is not all entries in the ht[] support 2pc */
bool no_2pc;
/* storage engines that registered in this transaction */
Ha_trx_info *ha_list;
/*
The purpose of this flag is to keep track of non-transactional
tables that were modified in scope of:
- transaction, when the variable is a member of
THD::transaction.all
- top-level statement or sub-statement, when the variable is a
member of THD::transaction.stmt
This member has the following life cycle:
* stmt.modified_non_trans_table is used to keep track of
modified non-transactional tables of top-level statements. At
the end of the previous statement and at the beginning of the session,
it is reset to FALSE. If such functions
as mysql_insert, mysql_update, mysql_delete etc modify a
non-transactional table, they set this flag to TRUE. At the
end of the statement, the value of stmt.modified_non_trans_table
is merged with all.modified_non_trans_table and gets reset.
* all.modified_non_trans_table is reset at the end of transaction
* Since we do not have a dedicated context for execution of a
sub-statement, to keep track of non-transactional changes in a
sub-statement, we re-use stmt.modified_non_trans_table.
At entrance into a sub-statement, a copy of the value of
stmt.modified_non_trans_table (containing the changes of the
outer statement) is saved on stack. Then
stmt.modified_non_trans_table is reset to FALSE and the
substatement is executed. Then the new value is merged with the
saved value.
*/
bool modified_non_trans_table;
void reset() {
no_2pc= FALSE;
modified_non_trans_table= FALSE;
m_unsafe_rollback_flags= 0;
}
bool is_empty() const { return ha_list == NULL; }
THD_TRANS() {} /* Remove gcc warning */
unsigned int m_unsafe_rollback_flags;
/*
Define the type of statemens which cannot be rolled back safely.
Each type occupies one bit in m_unsafe_rollback_flags.
*/
static unsigned int const MODIFIED_NON_TRANS_TABLE= 0x01;
static unsigned int const CREATED_TEMP_TABLE= 0x02;
static unsigned int const DROPPED_TEMP_TABLE= 0x04;
static unsigned int const DID_WAIT= 0x08;
void mark_created_temp_table()
{
DBUG_PRINT("debug", ("mark_created_temp_table"));
m_unsafe_rollback_flags|= CREATED_TEMP_TABLE;
}
void mark_trans_did_wait() { m_unsafe_rollback_flags|= DID_WAIT; }
bool trans_did_wait() const {
return (m_unsafe_rollback_flags & DID_WAIT) != 0;
}
};
/**
Either statement transaction or normal transaction - related
thread-specific storage engine data.
If a storage engine participates in a statement/transaction,
an instance of this class is present in
thd->transaction.{stmt|all}.ha_list. The addition to
{stmt|all}.ha_list is made by trans_register_ha().
When it's time to commit or rollback, each element of ha_list
is used to access storage engine's prepare()/commit()/rollback()
methods, and also to evaluate if a full two phase commit is
necessary.
@sa General description of transaction handling in handler.cc.
*/
class Ha_trx_info
{
public:
/** Register this storage engine in the given transaction context. */
void register_ha(THD_TRANS *trans, handlerton *ht_arg)
{
DBUG_ASSERT(m_flags == 0);
DBUG_ASSERT(m_ht == NULL);
DBUG_ASSERT(m_next == NULL);
m_ht= ht_arg;
m_flags= (int) TRX_READ_ONLY; /* Assume read-only at start. */
m_next= trans->ha_list;
trans->ha_list= this;
}
/** Clear, prepare for reuse. */
void reset()
{
m_next= NULL;
m_ht= NULL;
m_flags= 0;
}
Ha_trx_info() { reset(); }
void set_trx_read_write()
{
DBUG_ASSERT(is_started());
m_flags|= (int) TRX_READ_WRITE;
}
bool is_trx_read_write() const
{
DBUG_ASSERT(is_started());
return m_flags & (int) TRX_READ_WRITE;
}
bool is_started() const { return m_ht != NULL; }
/** Mark this transaction read-write if the argument is read-write. */
void coalesce_trx_with(const Ha_trx_info *stmt_trx)
{
/*
Must be called only after the transaction has been started.
Can be called many times, e.g. when we have many
read-write statements in a transaction.
*/
DBUG_ASSERT(is_started());
if (stmt_trx->is_trx_read_write())
set_trx_read_write();
}
Ha_trx_info *next() const
{
DBUG_ASSERT(is_started());
return m_next;
}
handlerton *ht() const
{
DBUG_ASSERT(is_started());
return m_ht;
}
private:
enum { TRX_READ_ONLY= 0, TRX_READ_WRITE= 1 };
/** Auxiliary, used for ha_list management */
Ha_trx_info *m_next;
/**
Although a given Ha_trx_info instance is currently always used
for the same storage engine, 'ht' is not-NULL only when the
corresponding storage is a part of a transaction.
*/
handlerton *m_ht;
/**
Transaction flags related to this engine.
Not-null only if this instance is a part of transaction.
May assume a combination of enum values above.
*/
uchar m_flags;
};
enum enum_tx_isolation { ISO_READ_UNCOMMITTED, ISO_READ_COMMITTED,
ISO_REPEATABLE_READ, ISO_SERIALIZABLE};
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;
time_t create_time;
time_t check_time;
time_t 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 ha_choice { HA_CHOICE_UNDEF, HA_CHOICE_NO, HA_CHOICE_YES, HA_CHOICE_MAX };
enum enum_stats_auto_recalc { HA_STATS_AUTO_RECALC_DEFAULT= 0,
HA_STATS_AUTO_RECALC_ON,
HA_STATS_AUTO_RECALC_OFF };
/**
A helper struct for schema DDL statements:
CREATE SCHEMA [IF NOT EXISTS] name [ schema_specification... ]
ALTER SCHEMA name [ schema_specification... ]
It stores the "schema_specification" part of the CREATE/ALTER statements and
is passed to mysql_create_db() and mysql_alter_db().
Currently consists only of the schema default character set and collation.
*/
struct Schema_specification_st
{
CHARSET_INFO *default_table_charset;
void init()
{
bzero(this, sizeof(*this));
}
};
/**
A helper struct for table DDL statements, e.g.:
CREATE [OR REPLACE] [TEMPORARY]
TABLE [IF NOT EXISTS] tbl_name table_contents_source;
Represents a combinations of:
1. The scope, i.e. TEMPORARY or not TEMPORARY
2. The "table_contents_source" part of the table DDL statements,
which can be initialized from either of these:
- table_element_list ... // Explicit definition (column and key list)
- LIKE another_table_name ... // Copy structure from another table
- [AS] SELECT ... // Copy structure from a subquery
*/
struct Table_scope_and_contents_source_st
{
CHARSET_INFO *table_charset;
LEX_CUSTRING tabledef_version;
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; ///< HA_OPTION_ values
ulong avg_row_length;
ulong used_fields;
ulong key_block_size;
/*
number of pages to sample during
stats estimation, if used, otherwise 0.
*/
uint stats_sample_pages;
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 */
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 specified inherits the value of the original table (if present).
*/
enum row_type row_type;
enum ha_choice transactional;
enum ha_storage_media storage_media; ///< DEFAULT, DISK or MEMORY
enum ha_choice page_checksum; ///< If we have page_checksums
engine_option_value *option_list; ///< list of table create options
enum_stats_auto_recalc stats_auto_recalc;
bool varchar; ///< 1 if table has a VARCHAR
/* the following three are only for ALTER TABLE, check_if_incompatible_data() */
ha_table_option_struct *option_struct; ///< structure with parsed table options
ha_field_option_struct **fields_option_struct; ///< array of field option structures
ha_index_option_struct **indexes_option_struct; ///< array of index option structures
/* The following is used to remember the old state for CREATE OR REPLACE */
TABLE *table;
TABLE_LIST *pos_in_locked_tables;
MDL_ticket *mdl_ticket;
bool table_was_deleted;
void init()
{
bzero(this, sizeof(*this));
}
bool tmp_table() const { return options & HA_LEX_CREATE_TMP_TABLE; }
void use_default_db_type(THD *thd)
{
db_type= tmp_table() ? ha_default_tmp_handlerton(thd)
: ha_default_handlerton(thd);
}
};
/**
This struct is passed to handler table routines, e.g. ha_create().
It does not include the "OR REPLACE" and "IF NOT EXISTS" parts, as these
parts are handled on the SQL level and are not needed on the handler level.
*/
struct HA_CREATE_INFO: public Table_scope_and_contents_source_st,
public Schema_specification_st
{
void init()
{
Table_scope_and_contents_source_st::init();
Schema_specification_st::init();
}
bool check_conflicting_charset_declarations(CHARSET_INFO *cs);
bool add_table_option_default_charset(CHARSET_INFO *cs)
{
// cs can be NULL, e.g.: CREATE TABLE t1 (..) CHARACTER SET DEFAULT;
if (check_conflicting_charset_declarations(cs))
return true;
default_table_charset= cs;
used_fields|= HA_CREATE_USED_DEFAULT_CHARSET;
return false;
}
bool add_alter_list_item_convert_to_charset(CHARSET_INFO *cs)
{
/*
cs cannot be NULL, as sql_yacc.yy translates
CONVERT TO CHARACTER SET DEFAULT
to
CONVERT TO CHARACTER SET <character-set-of-the-current-database>
TODO: Should't we postpone resolution of DEFAULT until the
character set of the table owner database is loaded from its db.opt?
*/
DBUG_ASSERT(cs);
if (check_conflicting_charset_declarations(cs))
return true;
table_charset= default_table_charset= cs;
used_fields|= (HA_CREATE_USED_CHARSET | HA_CREATE_USED_DEFAULT_CHARSET);
return false;
}
};
/**
This struct is passed to mysql_create_table() and similar creation functions,
as well as to show_create_table().
*/
struct Table_specification_st: public HA_CREATE_INFO,
public DDL_options_st
{
// Deep initialization
void init()
{
HA_CREATE_INFO::init();
DDL_options_st::init();
}
void init(DDL_options_st::Options options)
{
HA_CREATE_INFO::init();
DDL_options_st::init(options);
}
/*
Quick initialization, for parser.
Most of the HA_CREATE_INFO is left uninitialized.
It gets fully initialized in sql_yacc.yy, only when the parser
scans a related keyword (e.g. CREATE, ALTER).
*/
void lex_start()
{
HA_CREATE_INFO::options= 0;
DDL_options_st::init();
}
};
/**
In-place alter handler context.
This is a superclass intended to be subclassed by individual handlers
in order to store handler unique context between in-place alter API calls.
The handler is responsible for creating the object. This can be done
as early as during check_if_supported_inplace_alter().
The SQL layer is responsible for destroying the object.
The class extends Sql_alloc so the memory will be mem root allocated.
@see Alter_inplace_info
*/
class inplace_alter_handler_ctx : public Sql_alloc
{
public:
inplace_alter_handler_ctx() {}
virtual ~inplace_alter_handler_ctx() {}
};
/**
Class describing changes to be done by ALTER TABLE.
Instance of this class is passed to storage engine in order
to determine if this ALTER TABLE can be done using in-place
algorithm. It is also used for executing the ALTER TABLE
using in-place algorithm.
*/
class Alter_inplace_info
{
public:
/**
Bits to show in detail what operations the storage engine is
to execute.
All these operations are supported as in-place operations by the
SQL layer. This means that operations that by their nature must
be performed by copying the table to a temporary table, will not
have their own flags here.
We generally try to specify handler flags only if there are real
changes. But in cases when it is cumbersome to determine if some
attribute has really changed we might choose to set flag
pessimistically, for example, relying on parser output only.
*/
typedef ulong HA_ALTER_FLAGS;
// Add non-unique, non-primary index
static const HA_ALTER_FLAGS ADD_INDEX = 1L << 0;
// Drop non-unique, non-primary index
static const HA_ALTER_FLAGS DROP_INDEX = 1L << 1;
// Add unique, non-primary index
static const HA_ALTER_FLAGS ADD_UNIQUE_INDEX = 1L << 2;
// Drop unique, non-primary index
static const HA_ALTER_FLAGS DROP_UNIQUE_INDEX = 1L << 3;
// Add primary index
static const HA_ALTER_FLAGS ADD_PK_INDEX = 1L << 4;
// Drop primary index
static const HA_ALTER_FLAGS DROP_PK_INDEX = 1L << 5;
// Add column
static const HA_ALTER_FLAGS ADD_COLUMN = 1L << 6;
// Drop column
static const HA_ALTER_FLAGS DROP_COLUMN = 1L << 7;
// Rename column
static const HA_ALTER_FLAGS ALTER_COLUMN_NAME = 1L << 8;
// Change column datatype
static const HA_ALTER_FLAGS ALTER_COLUMN_TYPE = 1L << 9;
/**
Change column datatype in such way that new type has compatible
packed representation with old type, so it is theoretically
possible to perform change by only updating data dictionary
without changing table rows.
*/
static const HA_ALTER_FLAGS ALTER_COLUMN_EQUAL_PACK_LENGTH = 1L << 10;
// Reorder column
static const HA_ALTER_FLAGS ALTER_COLUMN_ORDER = 1L << 11;
// Change column from NOT NULL to NULL
static const HA_ALTER_FLAGS ALTER_COLUMN_NULLABLE = 1L << 12;
// Change column from NULL to NOT NULL
static const HA_ALTER_FLAGS ALTER_COLUMN_NOT_NULLABLE = 1L << 13;
// Set or remove default column value
static const HA_ALTER_FLAGS ALTER_COLUMN_DEFAULT = 1L << 14;
// Add foreign key
static const HA_ALTER_FLAGS ADD_FOREIGN_KEY = 1L << 15;
// Drop foreign key
static const HA_ALTER_FLAGS DROP_FOREIGN_KEY = 1L << 16;
// table_options changed, see HA_CREATE_INFO::used_fields for details.
static const HA_ALTER_FLAGS CHANGE_CREATE_OPTION = 1L << 17;
// Table is renamed
static const HA_ALTER_FLAGS ALTER_RENAME = 1L << 18;
// column's engine options changed, something in field->option_struct
static const HA_ALTER_FLAGS ALTER_COLUMN_OPTION = 1L << 19;
// MySQL alias for the same thing:
static const HA_ALTER_FLAGS ALTER_COLUMN_STORAGE_TYPE = 1L << 19;
// Change the column format of column
static const HA_ALTER_FLAGS ALTER_COLUMN_COLUMN_FORMAT = 1L << 20;
// Add partition
static const HA_ALTER_FLAGS ADD_PARTITION = 1L << 21;
// Drop partition
static const HA_ALTER_FLAGS DROP_PARTITION = 1L << 22;
// Changing partition options
static const HA_ALTER_FLAGS ALTER_PARTITION = 1L << 23;
// Coalesce partition
static const HA_ALTER_FLAGS COALESCE_PARTITION = 1L << 24;
// Reorganize partition ... into
static const HA_ALTER_FLAGS REORGANIZE_PARTITION = 1L << 25;
// Reorganize partition
static const HA_ALTER_FLAGS ALTER_TABLE_REORG = 1L << 26;
// Remove partitioning
static const HA_ALTER_FLAGS ALTER_REMOVE_PARTITIONING = 1L << 27;
// Partition operation with ALL keyword
static const HA_ALTER_FLAGS ALTER_ALL_PARTITION = 1L << 28;
/**
Recreate the table for ALTER TABLE FORCE, ALTER TABLE ENGINE
and OPTIMIZE TABLE operations.
*/
static const HA_ALTER_FLAGS RECREATE_TABLE = 1L << 29;
// Virtual columns changed
static const HA_ALTER_FLAGS ALTER_COLUMN_VCOL = 1L << 30;
// ALTER TABLE for a partitioned table
static const HA_ALTER_FLAGS ALTER_PARTITIONED = 1L << 31;
/**
Create options (like MAX_ROWS) for the new version of table.
@note The referenced instance of HA_CREATE_INFO object was already
used to create new .FRM file for table being altered. So it
has been processed by mysql_prepare_create_table() already.
For example, this means that it has HA_OPTION_PACK_RECORD
flag in HA_CREATE_INFO::table_options member correctly set.
*/
HA_CREATE_INFO *create_info;
/**
Alter options, fields and keys for the new version of table.
@note The referenced instance of Alter_info object was already
used to create new .FRM file for table being altered. So it
has been processed by mysql_prepare_create_table() already.
In particular, this means that in Create_field objects for
fields which were present in some form in the old version
of table, Create_field::field member points to corresponding
Field instance for old version of table.
*/
Alter_info *alter_info;
/**
Array of KEYs for new version of table - including KEYs to be added.
@note Currently this array is produced as result of
mysql_prepare_create_table() call.
This means that it follows different convention for
KEY_PART_INFO::fieldnr values than objects in TABLE::key_info
array.
@todo This is mainly due to the fact that we need to keep compatibility
with removed handler::add_index() call. We plan to switch to
TABLE::key_info numbering later.
KEYs are sorted - see sort_keys().
*/
KEY *key_info_buffer;
/** Size of key_info_buffer array. */
uint key_count;
/** Size of index_drop_buffer array. */
uint index_drop_count;
/**
Array of pointers to KEYs to be dropped belonging to the TABLE instance
for the old version of the table.
*/
KEY **index_drop_buffer;
/** Size of index_add_buffer array. */
uint index_add_count;
/**
Array of indexes into key_info_buffer for KEYs to be added,
sorted in increasing order.
*/
uint *index_add_buffer;
/**
Context information to allow handlers to keep context between in-place
alter API calls.
@see inplace_alter_handler_ctx for information about object lifecycle.
*/
inplace_alter_handler_ctx *handler_ctx;
/**
If the table uses several handlers, like ha_partition uses one handler
per partition, this contains a Null terminated array of ctx pointers
that should all be committed together.
Or NULL if only handler_ctx should be committed.
Set to NULL if the low level handler::commit_inplace_alter_table uses it,
to signal to the main handler that everything was committed as atomically.
@see inplace_alter_handler_ctx for information about object lifecycle.
*/
inplace_alter_handler_ctx **group_commit_ctx;
/**
Flags describing in detail which operations the storage engine is to execute.
*/
HA_ALTER_FLAGS handler_flags;
/**
Partition_info taking into account the partition changes to be performed.
Contains all partitions which are present in the old version of the table
with partitions to be dropped or changed marked as such + all partitions
to be added in the new version of table marked as such.
*/
partition_info *modified_part_info;
/** true for ALTER IGNORE TABLE ... */
const bool ignore;
/** true for online operation (LOCK=NONE) */
bool online;
/**
Can be set by handler to describe why a given operation cannot be done
in-place (HA_ALTER_INPLACE_NOT_SUPPORTED) or why it cannot be done
online (HA_ALTER_INPLACE_NO_LOCK or
HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE)
If set, it will be used with ER_ALTER_OPERATION_NOT_SUPPORTED_REASON if
results from handler::check_if_supported_inplace_alter() doesn't match
requirements set by user. If not set, the more generic
ER_ALTER_OPERATION_NOT_SUPPORTED will be used.
Please set to a properly localized string, for example using
my_get_err_msg(), so that the error message as a whole is localized.
*/
const char *unsupported_reason;
Alter_inplace_info(HA_CREATE_INFO *create_info_arg,
Alter_info *alter_info_arg,
KEY *key_info_arg, uint key_count_arg,
partition_info *modified_part_info_arg,
bool ignore_arg)
: create_info(create_info_arg),
alter_info(alter_info_arg),
key_info_buffer(key_info_arg),
key_count(key_count_arg),
index_drop_count(0),
index_drop_buffer(NULL),
index_add_count(0),
index_add_buffer(NULL),
handler_ctx(NULL),
group_commit_ctx(NULL),
handler_flags(0),
modified_part_info(modified_part_info_arg),
ignore(ignore_arg),
online(false),
unsupported_reason(NULL)
{}
~Alter_inplace_info()
{
delete handler_ctx;
}
/**
Used after check_if_supported_inplace_alter() to report
error if the result does not match the LOCK/ALGORITHM
requirements set by the user.
@param not_supported Part of statement that was not supported.
@param try_instead Suggestion as to what the user should
replace not_supported with.
*/
void report_unsupported_error(const char *not_supported,
const char *try_instead);
};
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).
*/
bool check_for_duplicate_indexes;
} KEY_CREATE_INFO;
/*
Class for maintaining hooks used inside operations on tables such
as: create table functions, delete table functions, and alter table
functions.
Class is using the Template Method pattern to separate the public
usage interface from the private inheritance interface. This
imposes no overhead, since the public non-virtual function is small
enough to be inlined.
The hooks are usually used for functions that does several things,
e.g., create_table_from_items(), which both create a table and lock
it.
*/
class TABLEOP_HOOKS
{
public:
TABLEOP_HOOKS() {}
virtual ~TABLEOP_HOOKS() {}
inline void prelock(TABLE **tables, uint count)
{
do_prelock(tables, count);
}
inline int postlock(TABLE **tables, uint count)
{
return do_postlock(tables, count);
}
private:
/* Function primitive that is called prior to locking tables */
virtual void do_prelock(TABLE **tables, uint count)
{
/* Default is to do nothing */
}
/**
Primitive called after tables are locked.
If an error is returned, the tables will be unlocked and error
handling start.
@return Error code or zero.
*/
virtual int do_postlock(TABLE **tables, uint count)
{
return 0; /* Default is to do nothing */
}
};
typedef struct st_savepoint SAVEPOINT;
extern ulong savepoint_alloc_size;
extern KEY_CREATE_INFO default_key_create_info;
/* Forward declaration for condition pushdown to storage engine */
typedef class Item COND;
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 */
time_t start_time; /* When check/repair starts */
KEY_CACHE *key_cache; /* new key cache when changing key cache */
void init();
} HA_CHECK_OPT;
/********************************************************************************
* MRR
********************************************************************************/
typedef void *range_seq_t;
typedef struct st_range_seq_if
{
/*
Get key information
SYNOPSIS
get_key_info()
init_params The seq_init_param parameter
length OUT length of the keys in this range sequence
map OUT key_part_map of the keys in this range sequence
DESCRIPTION
This function is set only when using HA_MRR_FIXED_KEY mode. In that mode,
all ranges are single-point equality ranges that use the same set of key
parts. This function allows the MRR implementation to get the length of
a key, and which keyparts it uses.
*/
void (*get_key_info)(void *init_params, uint *length, key_part_map *map);
/*
Initialize the traversal of range sequence
SYNOPSIS
init()
init_params The seq_init_param parameter
n_ranges The number of ranges obtained
flags A combination of HA_MRR_SINGLE_POINT, HA_MRR_FIXED_KEY
RETURN
An opaque value to be used as RANGE_SEQ_IF::next() parameter
*/
range_seq_t (*init)(void *init_params, uint n_ranges, uint flags);
/*
Get the next range in the range sequence
SYNOPSIS
next()
seq The value returned by RANGE_SEQ_IF::init()
range OUT Information about the next range
RETURN
FALSE - Ok, the range structure filled with info about the next range
TRUE - No more ranges
*/
bool (*next) (range_seq_t seq, KEY_MULTI_RANGE *range);
/*
Check whether range_info orders to skip the next record
SYNOPSIS
skip_record()
seq The value returned by RANGE_SEQ_IF::init()
range_info Information about the next range
(Ignored if MRR_NO_ASSOCIATION is set)
rowid Rowid of the record to be checked (ignored if set to 0)
RETURN
1 - Record with this range_info and/or this rowid shall be filtered
out from the stream of records returned by multi_range_read_next()
0 - The record shall be left in the stream
*/
bool (*skip_record) (range_seq_t seq, range_id_t range_info, uchar *rowid);
/*
Check if the record combination matches the index condition
SYNOPSIS
skip_index_tuple()
seq The value returned by RANGE_SEQ_IF::init()
range_info Information about the next range
RETURN
0 - The record combination satisfies the index condition
1 - Otherwise
*/
bool (*skip_index_tuple) (range_seq_t seq, range_id_t range_info);
} RANGE_SEQ_IF;
typedef bool (*SKIP_INDEX_TUPLE_FUNC) (range_seq_t seq, range_id_t range_info);
class Cost_estimate
{
public:
double io_count; /* number of I/O */
double avg_io_cost; /* cost of an average I/O oper. */
double cpu_cost; /* cost of operations in CPU */
double import_cost; /* cost of remote operations */
double mem_cost; /* cost of used memory */
enum { IO_COEFF=1 };
enum { CPU_COEFF=1 };
enum { MEM_COEFF=1 };
enum { IMPORT_COEFF=1 };
Cost_estimate()
{
reset();
}
double total_cost()
{
return IO_COEFF*io_count*avg_io_cost + CPU_COEFF * cpu_cost +
MEM_COEFF*mem_cost + IMPORT_COEFF*import_cost;
}
/**
Whether or not all costs in the object are zero
@return true if all costs are zero, false otherwise
*/
bool is_zero() const
{
return !(io_count || cpu_cost || import_cost || mem_cost);
}
void reset()
{
avg_io_cost= 1.0;
io_count= cpu_cost= mem_cost= import_cost= 0.0;
}
void multiply(double m)
{
io_count *= m;
cpu_cost *= m;
import_cost *= m;
/* Don't multiply mem_cost */
}
void add(const Cost_estimate* cost)
{
double io_count_sum= io_count + cost->io_count;
add_io(cost->io_count, cost->avg_io_cost);
io_count= io_count_sum;
cpu_cost += cost->cpu_cost;
}
void add_io(double add_io_cnt, double add_avg_cost)
{
/* In edge cases add_io_cnt may be zero */
if (add_io_cnt > 0)
{
double io_count_sum= io_count + add_io_cnt;
avg_io_cost= (io_count * avg_io_cost +
add_io_cnt * add_avg_cost) / io_count_sum;
io_count= io_count_sum;
}
}
/// Add to CPU cost
void add_cpu(double add_cpu_cost) { cpu_cost+= add_cpu_cost; }
/// Add to import cost
void add_import(double add_import_cost) { import_cost+= add_import_cost; }
/// Add to memory cost
void add_mem(double add_mem_cost) { mem_cost+= add_mem_cost; }
/*
To be used when we go from old single value-based cost calculations to
the new Cost_estimate-based.
*/
void convert_from_cost(double cost)
{
reset();
io_count= cost;
}
};
void get_sweep_read_cost(TABLE *table, ha_rows nrows, bool interrupted,
Cost_estimate *cost);
/*
Indicates that all scanned ranges will be singlepoint (aka equality) ranges.
The ranges may not use the full key but all of them will use the same number
of key parts.
*/
#define HA_MRR_SINGLE_POINT 1
#define HA_MRR_FIXED_KEY 2
/*
Indicates that RANGE_SEQ_IF::next(&range) doesn't need to fill in the
'range' parameter.
*/
#define HA_MRR_NO_ASSOCIATION 4
/*
The MRR user will provide ranges in key order, and MRR implementation
must return rows in key order.
*/
#define HA_MRR_SORTED 8
/* MRR implementation doesn't have to retrieve full records */
#define HA_MRR_INDEX_ONLY 16
/*
The passed memory buffer is of maximum possible size, the caller can't
assume larger buffer.
*/
#define HA_MRR_LIMITS 32
/*
Flag set <=> default MRR implementation is used
(The choice is made by **_info[_const]() function which may set this
flag. SQL layer remembers the flag value and then passes it to
multi_read_range_init().
*/
#define HA_MRR_USE_DEFAULT_IMPL 64
/*
Used only as parameter to multi_range_read_info():
Flag set <=> the caller guarantees that the bounds of the scanned ranges
will not have NULL values.
*/
#define HA_MRR_NO_NULL_ENDPOINTS 128
/*
The MRR user has materialized range keys somewhere in the user's buffer.
This can be used for optimization of the procedure that sorts these keys
since in this case key values don't have to be copied into the MRR buffer.
In other words, it is guaranteed that after RANGE_SEQ_IF::next() call the
pointer in range->start_key.key will point to a key value that will remain
there until the end of the MRR scan.
*/
#define HA_MRR_MATERIALIZED_KEYS 256
/*
The following bits are reserved for use by MRR implementation. The intended
use scenario:
* sql layer calls handler->multi_range_read_info[_const]()
- MRR implementation figures out what kind of scan it will perform, saves
the result in *mrr_mode parameter.
* sql layer remembers what was returned in *mrr_mode
* the optimizer picks the query plan (which may or may not include the MRR
scan that was estimated by the multi_range_read_info[_const] call)
* if the query is an EXPLAIN statement, sql layer will call
handler->multi_range_read_explain_info(mrr_mode) to get a text description
of the picked MRR scan; the description will be a part of EXPLAIN output.
*/
#define HA_MRR_IMPLEMENTATION_FLAG1 512
#define HA_MRR_IMPLEMENTATION_FLAG2 1024
#define HA_MRR_IMPLEMENTATION_FLAG3 2048
#define HA_MRR_IMPLEMENTATION_FLAG4 4096
#define HA_MRR_IMPLEMENTATION_FLAG5 8192
#define HA_MRR_IMPLEMENTATION_FLAG6 16384
#define HA_MRR_IMPLEMENTATION_FLAGS \
(512 | 1024 | 2048 | 4096 | 8192 | 16384)
/*
This is a buffer area that the handler can use to store rows.
'end_of_used_area' should be kept updated after calls to
read-functions so that other parts of the code can use the
remaining area (until next read calls is issued).
*/
typedef struct st_handler_buffer
{
/* const? */uchar *buffer; /* Buffer one can start using */
/* const? */uchar *buffer_end; /* End of buffer */
uchar *end_of_used_area; /* End of area that was used by handler */
} HANDLER_BUFFER;
typedef struct system_status_var SSV;
class ha_statistics
{
public:
ulonglong data_file_length; /* Length off data file */
ulonglong max_data_file_length; /* Length off data file */
ulonglong index_file_length;
ulonglong max_index_file_length;
ulonglong delete_length; /* Free bytes */
ulonglong auto_increment_value;
/*
The number of records in the table.
0 - means the table has exactly 0 rows
other - if (table_flags() & HA_STATS_RECORDS_IS_EXACT)
the value is the exact number of records in the table
else
it is an estimate
*/
ha_rows records;
ha_rows deleted; /* Deleted records */
ulong mean_rec_length; /* physical reclength */
time_t create_time; /* When table was created */
time_t check_time;
time_t update_time;
uint block_size; /* index block size */
/*
number of buffer bytes that native mrr implementation needs,
*/
uint mrr_length_per_rec;
ha_statistics():
data_file_length(0), max_data_file_length(0),
index_file_length(0), delete_length(0), auto_increment_value(0),
records(0), deleted(0), mean_rec_length(0), create_time(0),
check_time(0), update_time(0), block_size(0), mrr_length_per_rec(0)
{}
};
extern "C" enum icp_result handler_index_cond_check(void* h_arg);
uint calculate_key_len(TABLE *, uint, const uchar *, key_part_map);
/*
bitmap with first N+1 bits set
(keypart_map for a key prefix of [0..N] keyparts)
*/
#define make_keypart_map(N) (((key_part_map)2 << (N)) - 1)
/*
bitmap with first N bits set
(keypart_map for a key prefix of [0..N-1] keyparts)
*/
#define make_prev_keypart_map(N) (((key_part_map)1 << (N)) - 1)
/** Base class to be used by handlers different shares */
class Handler_share
{
public:
Handler_share() {}
virtual ~Handler_share() {}
};
/**
The handler class is the interface for dynamically loadable
storage engines. Do not add ifdefs and take care when adding or
changing virtual functions to avoid vtable confusion
Functions in this class accept and return table columns data. Two data
representation formats are used:
1. TableRecordFormat - Used to pass [partial] table records to/from
storage engine
2. KeyTupleFormat - used to pass index search tuples (aka "keys") to
storage engine. See opt_range.cc for description of this format.
TableRecordFormat
=================
[Warning: this description is work in progress and may be incomplete]
The table record is stored in a fixed-size buffer:
record: null_bytes, column1_data, column2_data, ...
The offsets of the parts of the buffer are also fixed: every column has
an offset to its column{i}_data, and if it is nullable it also has its own
bit in null_bytes.
The record buffer only includes data about columns that are marked in the
relevant column set (table->read_set and/or table->write_set, depending on
the situation).
<not-sure>It could be that it is required that null bits of non-present
columns are set to 1</not-sure>
VARIOUS EXCEPTIONS AND SPECIAL CASES
If the table has no nullable columns, then null_bytes is still
present, its length is one byte <not-sure> which must be set to 0xFF
at all times. </not-sure>
If the table has columns of type BIT, then certain bits from those columns
may be stored in null_bytes as well. Grep around for Field_bit for
details.
For blob columns (see Field_blob), the record buffer stores length of the
data, following by memory pointer to the blob data. The pointer is owned
by the storage engine and is valid until the next operation.
If a blob column has NULL value, then its length and blob data pointer
must be set to 0.
*/
class handler :public Sql_alloc
{
public:
typedef ulonglong Table_flags;
protected:
TABLE_SHARE *table_share; /* The table definition */
TABLE *table; /* The current open table */
Table_flags cached_table_flags; /* Set on init() and open() */
ha_rows estimation_rows_to_insert;
public:
handlerton *ht; /* storage engine of this handler */
uchar *ref; /* Pointer to current row */
uchar *dup_ref; /* Pointer to duplicate row */
ha_statistics stats;
/** MultiRangeRead-related members: */
range_seq_t mrr_iter; /* Interator to traverse the range sequence */
RANGE_SEQ_IF mrr_funcs; /* Range sequence traversal functions */
HANDLER_BUFFER *multi_range_buffer; /* MRR buffer info */
uint ranges_in_seq; /* Total number of ranges in the traversed sequence */
/* TRUE <=> source MRR ranges and the output are ordered */
bool mrr_is_output_sorted;
/** TRUE <=> we're currently traversing a range in mrr_cur_range. */
bool mrr_have_range;
/** Current range (the one we're now returning rows from) */
KEY_MULTI_RANGE mrr_cur_range;
/** The following are for read_range() */
key_range save_end_range, *end_range;
KEY_PART_INFO *range_key_part;
int key_compare_result_on_equal;
bool eq_range;
bool internal_tmp_table; /* If internal tmp table */
uint errkey; /* Last dup key */
uint key_used_on_scan;
uint active_index;
/*
TRUE <=> the engine guarantees that returned records are within the range
being scanned.
*/
bool in_range_check_pushed_down;
/** Length of ref (1-8 or the clustered key length) */
uint ref_length;
FT_INFO *ft_handler;
enum {NONE=0, INDEX, RND} inited;
bool implicit_emptied; /* Can be !=0 only if HEAP */
const COND *pushed_cond;
/**
next_insert_id is the next value which should be inserted into the
auto_increment column: in a inserting-multi-row statement (like INSERT
SELECT), for the first row where the autoinc value is not specified by the
statement, get_auto_increment() called and asked to generate a value,
next_insert_id is set to the next value, then for all other rows
next_insert_id is used (and increased each time) without calling
get_auto_increment().
*/
ulonglong next_insert_id;
/**
insert id for the current row (*autogenerated*; if not
autogenerated, it's 0).
At first successful insertion, this variable is stored into
THD::first_successful_insert_id_in_cur_stmt.
*/
ulonglong insert_id_for_cur_row;
/**
Interval returned by get_auto_increment() and being consumed by the
inserter.
*/
/* Statistics variables */
ulonglong rows_read;
ulonglong rows_tmp_read;
ulonglong rows_changed;
/* One bigger than needed to avoid to test if key == MAX_KEY */
ulonglong index_rows_read[MAX_KEY+1];
private:
/* ANALYZE time tracker, if present */
Exec_time_tracker *tracker;
public:
void set_time_tracker(Exec_time_tracker *tracker_arg) { tracker=tracker_arg;}
Item *pushed_idx_cond;
uint pushed_idx_cond_keyno; /* The index which the above condition is for */
Discrete_interval auto_inc_interval_for_cur_row;
/**
Number of reserved auto-increment intervals. Serves as a heuristic
when we have no estimation of how many records the statement will insert:
the more intervals we have reserved, the bigger the next one. Reset in
handler::ha_release_auto_increment().
*/
uint auto_inc_intervals_count;
/**
Instrumented table associated with this handler.
This member should be set to NULL when no instrumentation is in place,
so that linking an instrumented/non instrumented server/plugin works.
For example:
- the server is compiled with the instrumentation.
The server expects either NULL or valid pointers in m_psi.
- an engine plugin is compiled without instrumentation.
The plugin can not leave this pointer uninitialized,
or can not leave a trash value on purpose in this pointer,
as this would crash the server.
*/
PSI_table *m_psi;
virtual void unbind_psi();
virtual void rebind_psi();
private:
/**
The lock type set by when calling::ha_external_lock(). This is
propagated down to the storage engine. The reason for also storing
it here, is that when doing MRR we need to create/clone a second handler
object. This cloned handler object needs to know about the lock_type used.
*/
int m_lock_type;
/**
Pointer where to store/retrieve the Handler_share pointer.
For non partitioned handlers this is &TABLE_SHARE::ha_share.
*/
Handler_share **ha_share;
public:
handler(handlerton *ht_arg, TABLE_SHARE *share_arg)
:table_share(share_arg), table(0),
estimation_rows_to_insert(0), ht(ht_arg),
ref(0), end_range(NULL), key_used_on_scan(MAX_KEY), active_index(MAX_KEY),
in_range_check_pushed_down(FALSE),
ref_length(sizeof(my_off_t)),
ft_handler(0), inited(NONE),
implicit_emptied(0),
pushed_cond(0), next_insert_id(0), insert_id_for_cur_row(0),
tracker(NULL),
pushed_idx_cond(NULL),
pushed_idx_cond_keyno(MAX_KEY),
auto_inc_intervals_count(0),
m_psi(NULL), m_lock_type(F_UNLCK), ha_share(NULL)
{
DBUG_PRINT("info",
("handler created F_UNLCK %d F_RDLCK %d F_WRLCK %d",
F_UNLCK, F_RDLCK, F_WRLCK));
reset_statistics();
}
virtual ~handler(void)
{
DBUG_ASSERT(m_lock_type == F_UNLCK);
DBUG_ASSERT(inited == NONE);
}
virtual handler *clone(const char *name, MEM_ROOT *mem_root);
/** This is called after create to allow us to set up cached variables */
void init()
{
cached_table_flags= table_flags();
}
/* ha_ methods: pubilc wrappers for private virtual API */
int ha_open(TABLE *table, const char *name, int mode, uint test_if_locked);
int ha_index_init(uint idx, bool sorted)
{
DBUG_EXECUTE_IF("ha_index_init_fail", return HA_ERR_TABLE_DEF_CHANGED;);
int result;
DBUG_ENTER("ha_index_init");
DBUG_ASSERT(inited==NONE);
if (!(result= index_init(idx, sorted)))
{
inited= INDEX;
active_index= idx;
end_range= NULL;
}
DBUG_RETURN(result);
}
int ha_index_end()
{
DBUG_ENTER("ha_index_end");
DBUG_ASSERT(inited==INDEX);
inited= NONE;
active_index= MAX_KEY;
end_range= NULL;
DBUG_RETURN(index_end());
}
/* This is called after index_init() if we need to do a index scan */
virtual int prepare_index_scan() { return 0; }
virtual int prepare_index_key_scan_map(const uchar * key, key_part_map keypart_map)
{
uint key_len= calculate_key_len(table, active_index, key, keypart_map);
return prepare_index_key_scan(key, key_len);
}
virtual int prepare_index_key_scan( const uchar * key, uint key_len )
{ return 0; }
virtual int prepare_range_scan(const key_range *start_key, const key_range *end_key)
{ return 0; }
int ha_rnd_init(bool scan) __attribute__ ((warn_unused_result))
{
DBUG_EXECUTE_IF("ha_rnd_init_fail", return HA_ERR_TABLE_DEF_CHANGED;);
int result;
DBUG_ENTER("ha_rnd_init");
DBUG_ASSERT(inited==NONE || (inited==RND && scan));
inited= (result= rnd_init(scan)) ? NONE: RND;
end_range= NULL;
DBUG_RETURN(result);
}
int ha_rnd_end()
{
DBUG_ENTER("ha_rnd_end");
DBUG_ASSERT(inited==RND);
inited=NONE;
end_range= NULL;
DBUG_RETURN(rnd_end());
}
int ha_rnd_init_with_error(bool scan) __attribute__ ((warn_unused_result));
int ha_reset();
/* this is necessary in many places, e.g. in HANDLER command */
int ha_index_or_rnd_end()
{
return inited == INDEX ? ha_index_end() : inited == RND ? ha_rnd_end() : 0;
}
/**
The cached_table_flags is set at ha_open and ha_external_lock
*/
Table_flags ha_table_flags() const { return cached_table_flags; }
/**
These functions represent the public interface to *users* of the
handler class, hence they are *not* virtual. For the inheritance
interface, see the (private) functions write_row(), update_row(),
and delete_row() below.
*/
int ha_external_lock(THD *thd, int lock_type);
int ha_write_row(uchar * buf);
int ha_update_row(const uchar * old_data, uchar * new_data);
int ha_delete_row(const uchar * buf);
void ha_release_auto_increment();
int check_collation_compatibility();
int ha_check_for_upgrade(HA_CHECK_OPT *check_opt);
/** to be actually called to get 'check()' functionality*/
int ha_check(THD *thd, HA_CHECK_OPT *check_opt);
int ha_repair(THD* thd, HA_CHECK_OPT* check_opt);
void ha_start_bulk_insert(ha_rows rows, uint flags= 0)
{
DBUG_ENTER("handler::ha_start_bulk_insert");
estimation_rows_to_insert= rows;
start_bulk_insert(rows, flags);
DBUG_VOID_RETURN;
}
int ha_end_bulk_insert()
{
DBUG_ENTER("handler::ha_end_bulk_insert");
estimation_rows_to_insert= 0;
int ret= end_bulk_insert();
DBUG_RETURN(ret);
}
int ha_bulk_update_row(const uchar *old_data, uchar *new_data,
uint *dup_key_found);
int ha_delete_all_rows();
int ha_truncate();
int ha_reset_auto_increment(ulonglong value);
int ha_optimize(THD* thd, HA_CHECK_OPT* check_opt);
int ha_analyze(THD* thd, HA_CHECK_OPT* check_opt);
bool ha_check_and_repair(THD *thd);
int ha_disable_indexes(uint mode);
int ha_enable_indexes(uint mode);
int ha_discard_or_import_tablespace(my_bool discard);
int ha_rename_table(const char *from, const char *to);
int ha_delete_table(const char *name);
void ha_drop_table(const char *name);
int ha_create(const char *name, TABLE *form, HA_CREATE_INFO *info);
int ha_create_partitioning_metadata(const char *name, const char *old_name,
int action_flag);
int ha_change_partitions(HA_CREATE_INFO *create_info,
const char *path,
ulonglong * const copied,
ulonglong * const deleted,
const uchar *pack_frm_data,
size_t pack_frm_len);
int ha_drop_partitions(const char *path);
int ha_rename_partitions(const char *path);
void adjust_next_insert_id_after_explicit_value(ulonglong nr);
int update_auto_increment();
virtual void print_error(int error, myf errflag);
virtual bool get_error_message(int error, String *buf);
uint get_dup_key(int error);
/**
Retrieves the names of the table and the key for which there was a
duplicate entry in the case of HA_ERR_FOREIGN_DUPLICATE_KEY.
If any of the table or key name is not available this method will return
false and will not change any of child_table_name or child_key_name.
@param child_table_name[out] Table name
@param child_table_name_len[in] Table name buffer size
@param child_key_name[out] Key name
@param child_key_name_len[in] Key name buffer size
@retval true table and key names were available
and were written into the corresponding
out parameters.
@retval false table and key names were not available,
the out parameters were not touched.
*/
virtual bool get_foreign_dup_key(char *child_table_name,
uint child_table_name_len,
char *child_key_name,
uint child_key_name_len)
{ DBUG_ASSERT(false); return(false); }
void reset_statistics()
{
rows_read= rows_changed= rows_tmp_read= 0;
bzero(index_rows_read, sizeof(index_rows_read));
}
virtual void change_table_ptr(TABLE *table_arg, TABLE_SHARE *share)
{
table= table_arg;
table_share= share;
reset_statistics();
}
virtual double scan_time()
{ return ulonglong2double(stats.data_file_length) / IO_SIZE + 2; }
/**
The cost of reading a set of ranges from the table using an index
to access it.
@param index The index number.
@param ranges The number of ranges to be read.
@param rows Total number of rows to be read.
This method can be used to calculate the total cost of scanning a table
using an index by calling it using read_time(index, 1, table_size).
*/
virtual double read_time(uint index, uint ranges, ha_rows rows)
{ return rows2double(ranges+rows); }
/**
Calculate cost of 'keyread' scan for given index and number of records.
@param index index to read
@param ranges #of ranges to read
@param rows #of records to read
*/
virtual double keyread_time(uint index, uint ranges, ha_rows rows);
virtual const key_map *keys_to_use_for_scanning() { return &key_map_empty; }
bool has_transactions()
{ return (ha_table_flags() & HA_NO_TRANSACTIONS) == 0; }
virtual uint extra_rec_buf_length() const { return 0; }
/**
This method is used to analyse the error to see whether the error
is ignorable or not, certain handlers can have more error that are
ignorable than others. E.g. the partition handler can get inserts
into a range where there is no partition and this is an ignorable
error.
HA_ERR_FOUND_DUP_UNIQUE is a special case in MyISAM that means the
same thing as HA_ERR_FOUND_DUP_KEY but can in some cases lead to
a slightly different error message.
*/
virtual bool is_fatal_error(int error, uint flags)
{
if (!error ||
((flags & HA_CHECK_DUP_KEY) &&
(error == HA_ERR_FOUND_DUPP_KEY ||
error == HA_ERR_FOUND_DUPP_UNIQUE)) ||
error == HA_ERR_AUTOINC_ERANGE)
return FALSE;
return TRUE;
}
/**
Number of rows in table. It will only be called if
(table_flags() & (HA_HAS_RECORDS | HA_STATS_RECORDS_IS_EXACT)) != 0
*/
virtual ha_rows records() { return stats.records; }
/**
Return upper bound of current number of records in the table
(max. of how many records one will retrieve when doing a full table scan)
If upper bound is not known, HA_POS_ERROR should be returned as a max
possible upper bound.
*/
virtual ha_rows estimate_rows_upper_bound()
{ return stats.records+EXTRA_RECORDS; }
/**
Get the row type from the storage engine. If this method returns
ROW_TYPE_NOT_USED, the information in HA_CREATE_INFO should be used.
*/
virtual enum row_type get_row_type() const { return ROW_TYPE_NOT_USED; }
virtual const char *index_type(uint key_number) { DBUG_ASSERT(0); return "";}
/**
Signal that the table->read_set and table->write_set table maps changed
The handler is allowed to set additional bits in the above map in this
call. Normally the handler should ignore all calls until we have done
a ha_rnd_init() or ha_index_init(), write_row(), update_row or delete_row()
as there may be several calls to this routine.
*/
virtual void column_bitmaps_signal();
/*
We have to check for inited as some engines, like innodb, sets
active_index during table scan.
*/
uint get_index(void) const
{ return inited == INDEX ? active_index : MAX_KEY; }
int ha_close(void);
/**
@retval 0 Bulk update used by handler
@retval 1 Bulk update not used, normal operation used
*/
virtual bool start_bulk_update() { return 1; }
/**
@retval 0 Bulk delete used by handler
@retval 1 Bulk delete not used, normal operation used
*/
virtual bool start_bulk_delete() { return 1; }
/**
After this call all outstanding updates must be performed. The number
of duplicate key errors are reported in the duplicate key parameter.
It is allowed to continue to the batched update after this call, the
handler has to wait until end_bulk_update with changing state.
@param dup_key_found Number of duplicate keys found
@retval 0 Success
@retval >0 Error code
*/
virtual int exec_bulk_update(uint *dup_key_found)
{
DBUG_ASSERT(FALSE);
return HA_ERR_WRONG_COMMAND;
}
/**
Perform any needed clean-up, no outstanding updates are there at the
moment.
*/
virtual void end_bulk_update() { return; }
/**
Execute all outstanding deletes and close down the bulk delete.
@retval 0 Success
@retval >0 Error code
*/
virtual int end_bulk_delete()
{
DBUG_ASSERT(FALSE);
return HA_ERR_WRONG_COMMAND;
}
/**
@brief
Positions an index cursor to the index specified in the
handle. Fetches the row if available. If the key value is null,
begin at the first key of the index.
*/
protected:
virtual int index_read_map(uchar * buf, const uchar * key,
key_part_map keypart_map,
enum ha_rkey_function find_flag)
{
uint key_len= calculate_key_len(table, active_index, key, keypart_map);
return index_read(buf, key, key_len, find_flag);
}
/**
@brief
Positions an index cursor to the index specified in the
handle. Fetches the row if available. If the key value is null,
begin at the first key of the index.
*/
virtual int index_read_idx_map(uchar * buf, uint index, const uchar * key,
key_part_map keypart_map,
enum ha_rkey_function find_flag);
virtual int index_next(uchar * buf)
{ return HA_ERR_WRONG_COMMAND; }
virtual int index_prev(uchar * buf)
{ return HA_ERR_WRONG_COMMAND; }
virtual int index_first(uchar * buf)
{ return HA_ERR_WRONG_COMMAND; }
virtual int index_last(uchar * buf)
{ return HA_ERR_WRONG_COMMAND; }
virtual int index_next_same(uchar *buf, const uchar *key, uint keylen);
virtual int close(void)=0;
inline void update_rows_read()
{
if (likely(!internal_tmp_table))
rows_read++;
else
rows_tmp_read++;
}
inline void update_index_statistics()
{
index_rows_read[active_index]++;
update_rows_read();
}
public:
int ha_index_read_map(uchar * buf, const uchar * key,
key_part_map keypart_map,
enum ha_rkey_function find_flag);
int ha_index_read_idx_map(uchar * buf, uint index, const uchar * key,
key_part_map keypart_map,
enum ha_rkey_function find_flag);
int ha_index_next(uchar * buf);
int ha_index_prev(uchar * buf);
int ha_index_first(uchar * buf);
int ha_index_last(uchar * buf);
int ha_index_next_same(uchar *buf, const uchar *key, uint keylen);
/*
TODO: should we make for those functions non-virtual ha_func_name wrappers,
too?
*/
virtual ha_rows multi_range_read_info_const(uint keyno, RANGE_SEQ_IF *seq,
void *seq_init_param,
uint n_ranges, uint *bufsz,
uint *mrr_mode,
Cost_estimate *cost);
virtual ha_rows multi_range_read_info(uint keyno, uint n_ranges, uint keys,
uint key_parts, uint *bufsz,
uint *mrr_mode, Cost_estimate *cost);
virtual int multi_range_read_init(RANGE_SEQ_IF *seq, void *seq_init_param,
uint n_ranges, uint mrr_mode,
HANDLER_BUFFER *buf);
virtual int multi_range_read_next(range_id_t *range_info);
/*
Return string representation of the MRR plan.
This is intended to be used for EXPLAIN, via the following scenario:
1. SQL layer calls handler->multi_range_read_info().
1.1. Storage engine figures out whether it will use some non-default
MRR strategy, sets appropritate bits in *mrr_mode, and returns
control to SQL layer
2. SQL layer remembers the returned mrr_mode
3. SQL layer compares various options and choses the final query plan. As
a part of that, it makes a choice of whether to use the MRR strategy
picked in 1.1
4. EXPLAIN code converts the query plan to its text representation. If MRR
strategy is part of the plan, it calls
multi_range_read_explain_info(mrr_mode) to get a text representation of
the picked MRR strategy.
@param mrr_mode Mode which was returned by multi_range_read_info[_const]
@param str INOUT string to be printed for EXPLAIN
@param str_end End of the string buffer. The function is free to put the
string into [str..str_end] memory range.
*/
virtual int multi_range_read_explain_info(uint mrr_mode, char *str,
size_t size)
{ return 0; }
virtual int read_range_first(const key_range *start_key,
const key_range *end_key,
bool eq_range, bool sorted);
virtual int read_range_next();
void set_end_range(const key_range *end_key);
int compare_key(key_range *range);
int compare_key2(key_range *range);
virtual int ft_init() { return HA_ERR_WRONG_COMMAND; }
void ft_end() { ft_handler=NULL; }
virtual FT_INFO *ft_init_ext(uint flags, uint inx,String *key)
{ return NULL; }
private:
virtual int ft_read(uchar *buf) { return HA_ERR_WRONG_COMMAND; }
virtual int rnd_next(uchar *buf)=0;
virtual int rnd_pos(uchar * buf, uchar *pos)=0;
/**
This function only works for handlers having
HA_PRIMARY_KEY_REQUIRED_FOR_POSITION set.
It will return the row with the PK given in the record argument.
*/
virtual int rnd_pos_by_record(uchar *record)
{
DBUG_ASSERT(table_flags() & HA_PRIMARY_KEY_REQUIRED_FOR_POSITION);
position(record);
return rnd_pos(record, ref);
}
virtual int read_first_row(uchar *buf, uint primary_key);
public:
/* Same as above, but with statistics */
inline int ha_ft_read(uchar *buf);
int ha_rnd_next(uchar *buf);
int ha_rnd_pos(uchar *buf, uchar *pos);
inline int ha_rnd_pos_by_record(uchar *buf);
inline int ha_read_first_row(uchar *buf, uint primary_key);
/**
The following 3 function is only needed for tables that may be
internal temporary tables during joins.
*/
virtual int remember_rnd_pos()
{ return HA_ERR_WRONG_COMMAND; }
virtual int restart_rnd_next(uchar *buf)
{ return HA_ERR_WRONG_COMMAND; }
virtual int rnd_same(uchar *buf, uint inx)
{ return HA_ERR_WRONG_COMMAND; }
virtual ha_rows records_in_range(uint inx, key_range *min_key,
key_range *max_key)
{ return (ha_rows) 10; }
/*
If HA_PRIMARY_KEY_REQUIRED_FOR_POSITION is set, then it sets ref
(reference to the row, aka position, with the primary key given in
the record).
Otherwise it set ref to the current row.
*/
virtual void position(const uchar *record)=0;
virtual int info(uint)=0; // see my_base.h for full description
virtual void get_dynamic_partition_info(PARTITION_STATS *stat_info,
uint part_id);
virtual int extra(enum ha_extra_function operation)
{ return 0; }
virtual int extra_opt(enum ha_extra_function operation, ulong cache_size)
{ return extra(operation); }
/**
In an UPDATE or DELETE, if the row under the cursor was locked by another
transaction, and the engine used an optimistic read of the last
committed row value under the cursor, then the engine returns 1 from this
function. MySQL must NOT try to update this optimistic value. If the
optimistic value does not match the WHERE condition, MySQL can decide to
skip over this row. Currently only works for InnoDB. This can be used to
avoid unnecessary lock waits.
If this method returns nonzero, it will also signal the storage
engine that the next read will be a locking re-read of the row.
*/
virtual bool was_semi_consistent_read() { return 0; }
/**
Tell the engine whether it should avoid unnecessary lock waits.
If yes, in an UPDATE or DELETE, if the row under the cursor was locked
by another transaction, the engine may try an optimistic read of
the last committed row value under the cursor.
*/
virtual void try_semi_consistent_read(bool) {}
virtual void unlock_row() {}
virtual int start_stmt(THD *thd, thr_lock_type lock_type) {return 0;}
virtual void get_auto_increment(ulonglong offset, ulonglong increment,
ulonglong nb_desired_values,
ulonglong *first_value,
ulonglong *nb_reserved_values);
void set_next_insert_id(ulonglong id)
{
DBUG_PRINT("info",("auto_increment: next value %lu", (ulong)id));
next_insert_id= id;
}
void restore_auto_increment(ulonglong prev_insert_id)
{
/*
Insertion of a row failed, re-use the lastly generated auto_increment
id, for the next row. This is achieved by resetting next_insert_id to
what it was before the failed insertion (that old value is provided by
the caller). If that value was 0, it was the first row of the INSERT;
then if insert_id_for_cur_row contains 0 it means no id was generated
for this first row, so no id was generated since the INSERT started, so
we should set next_insert_id to 0; if insert_id_for_cur_row is not 0, it
is the generated id of the first and failed row, so we use it.
*/
next_insert_id= (prev_insert_id > 0) ? prev_insert_id :
insert_id_for_cur_row;
}
virtual void update_create_info(HA_CREATE_INFO *create_info) {}
int check_old_types();
virtual int assign_to_keycache(THD* thd, HA_CHECK_OPT* check_opt)
{ return HA_ADMIN_NOT_IMPLEMENTED; }
virtual int preload_keys(THD* thd, HA_CHECK_OPT* check_opt)
{ return HA_ADMIN_NOT_IMPLEMENTED; }
/* end of the list of admin commands */
virtual int indexes_are_disabled(void) {return 0;}
virtual char *update_table_comment(const char * comment)
{ return (char*) comment;}
virtual void append_create_info(String *packet) {}
/**
If index == MAX_KEY then a check for table is made and if index <
MAX_KEY then a check is made if the table has foreign keys and if
a foreign key uses this index (and thus the index cannot be dropped).
@param index Index to check if foreign key uses it
@retval TRUE Foreign key defined on table or index
@retval FALSE No foreign key defined
*/
virtual bool is_fk_defined_on_table_or_index(uint index)
{ return FALSE; }
virtual char* get_foreign_key_create_info()
{ return(NULL);} /* gets foreign key create string from InnoDB */
/**
Used in ALTER TABLE to check if changing storage engine is allowed.
@note Called without holding thr_lock.c lock.
@retval true Changing storage engine is allowed.
@retval false Changing storage engine not allowed.
*/
virtual bool can_switch_engines() { return true; }
virtual int can_continue_handler_scan() { return 0; }
/**
Get the list of foreign keys in this table.
@remark Returns the set of foreign keys where this table is the
dependent or child table.
@param thd The thread handle.
@param f_key_list[out] The list of foreign keys.
@return The handler error code or zero for success.
*/
virtual int
get_foreign_key_list(THD *thd, List<FOREIGN_KEY_INFO> *f_key_list)
{ return 0; }
/**
Get the list of foreign keys referencing this table.
@remark Returns the set of foreign keys where this table is the
referenced or parent table.
@param thd The thread handle.
@param f_key_list[out] The list of foreign keys.
@return The handler error code or zero for success.
*/
virtual int
get_parent_foreign_key_list(THD *thd, List<FOREIGN_KEY_INFO> *f_key_list)
{ return 0; }
virtual uint referenced_by_foreign_key() { return 0;}
virtual void init_table_handle_for_HANDLER()
{ return; } /* prepare InnoDB for HANDLER */
virtual void free_foreign_key_create_info(char* str) {}
/** The following can be called without an open handler */
const char *table_type() const { return hton_name(ht)->str; }
const char **bas_ext() const { return ht->tablefile_extensions; }
virtual int get_default_no_partitions(HA_CREATE_INFO *create_info)
{ return 1;}
virtual void set_auto_partitions(partition_info *part_info) { return; }
virtual bool get_no_parts(const char *name,
uint *no_parts)
{
*no_parts= 0;
return 0;
}
virtual void set_part_info(partition_info *part_info) {return;}
virtual ulong index_flags(uint idx, uint part, bool all_parts) const =0;
uint max_record_length() const
{ return MY_MIN(HA_MAX_REC_LENGTH, max_supported_record_length()); }
uint max_keys() const
{ return MY_MIN(MAX_KEY, max_supported_keys()); }
uint max_key_parts() const
{ return MY_MIN(MAX_REF_PARTS, max_supported_key_parts()); }
uint max_key_length() const
{ return MY_MIN(MAX_KEY_LENGTH, max_supported_key_length()); }
uint max_key_part_length() const
{ return MY_MIN(MAX_KEY_LENGTH, max_supported_key_part_length()); }
virtual uint max_supported_record_length() const { return HA_MAX_REC_LENGTH; }
virtual uint max_supported_keys() const { return 0; }
virtual uint max_supported_key_parts() const { return MAX_REF_PARTS; }
virtual uint max_supported_key_length() const { return MAX_KEY_LENGTH; }
virtual uint max_supported_key_part_length() const { return 255; }
virtual uint min_record_length(uint options) const { return 1; }
virtual uint checksum() const { return 0; }
virtual bool is_crashed() const { return 0; }
virtual bool auto_repair(int error) const { return 0; }
void update_global_table_stats();
void update_global_index_stats();
#define CHF_CREATE_FLAG 0
#define CHF_DELETE_FLAG 1
#define CHF_RENAME_FLAG 2
#define CHF_INDEX_FLAG 3
/**
@note lock_count() can return > 1 if the table is MERGE or partitioned.
*/
virtual uint lock_count(void) const { return 1; }
/**
Is not invoked for non-transactional temporary tables.
@note store_lock() can return more than one lock if the table is MERGE
or partitioned.
@note that one can NOT rely on table->in_use in store_lock(). It may
refer to a different thread if called from mysql_lock_abort_for_thread().
@note If the table is MERGE, store_lock() can return less locks
than lock_count() claimed. This can happen when the MERGE children
are not attached when this is called from another thread.
*/
virtual THR_LOCK_DATA **store_lock(THD *thd,
THR_LOCK_DATA **to,
enum thr_lock_type lock_type)=0;
/** Type of table for caching query */
virtual uint8 table_cache_type() { return HA_CACHE_TBL_NONTRANSACT; }
/**
@brief Register a named table with a call back function to the query cache.
@param thd The thread handle
@param table_key A pointer to the table name in the table cache
@param key_length The length of the table name
@param[out] engine_callback The pointer to the storage engine call back
function
@param[out] engine_data Storage engine specific data which could be
anything
This method offers the storage engine, the possibility to store a reference
to a table name which is going to be used with query cache.
The method is called each time a statement is written to the cache and can
be used to verify if a specific statement is cachable. It also offers
the possibility to register a generic (but static) call back function which
is called each time a statement is matched against the query cache.
@note If engine_data supplied with this function is different from
engine_data supplied with the callback function, and the callback returns
FALSE, a table invalidation on the current table will occur.
@return Upon success the engine_callback will point to the storage engine
call back function, if any, and engine_data will point to any storage
engine data used in the specific implementation.
@retval TRUE Success
@retval FALSE The specified table or current statement should not be
cached
*/
virtual my_bool register_query_cache_table(THD *thd, char *table_key,
uint key_length,
qc_engine_callback
*engine_callback,
ulonglong *engine_data)
{
*engine_callback= 0;
return TRUE;
}
/*
Count tables invisible from all tables list on which current one built
(like myisammrg and partitioned tables)
tables_type mask for the tables should be added herdde
returns number of such tables
*/
virtual uint count_query_cache_dependant_tables(uint8 *tables_type
__attribute__((unused)))
{
return 0;
}
/*
register tables invisible from all tables list on which current one built
(like myisammrg and partitioned tables).
@note they should be counted by method above
cache Query cache pointer
block Query cache block to write the table
n Number of the table
@retval FALSE - OK
@retval TRUE - Error
*/
virtual my_bool
register_query_cache_dependant_tables(THD *thd
__attribute__((unused)),
Query_cache *cache
__attribute__((unused)),
Query_cache_block_table **block
__attribute__((unused)),
uint *n __attribute__((unused)))
{
return FALSE;
}
/*
Check if the primary key (if there is one) is a clustered and a
reference key. This means:
- Data is stored together with the primary key (no secondary lookup
needed to find the row data). The optimizer uses this to find out
the cost of fetching data.
- The primary key is part of each secondary key and is used
to find the row data in the primary index when reading trough
secondary indexes.
- When doing a HA_KEYREAD_ONLY we get also all the primary key parts
into the row. This is critical property used by index_merge.
All the above is usually true for engines that store the row
data in the primary key index (e.g. in a b-tree), and use the primary
key value as a position(). InnoDB is an example of such an engine.
For such a clustered primary key, the following should also hold:
index_flags() should contain HA_CLUSTERED_INDEX
table_flags() should contain HA_TABLE_SCAN_ON_INDEX
@retval TRUE yes
@retval FALSE No.
*/
virtual bool primary_key_is_clustered() { return FALSE; }
virtual int cmp_ref(const uchar *ref1, const uchar *ref2)
{
return memcmp(ref1, ref2, ref_length);
}
/*
Condition pushdown to storage engines
*/
/**
Push condition down to the table handler.
@param cond Condition to be pushed. The condition tree must not be
modified by the by the caller.
@return
The 'remainder' condition that caller must use to filter out records.
NULL means the handler will not return rows that do not match the
passed condition.
@note
The pushed conditions form a stack (from which one can remove the
last pushed condition using cond_pop).
The table handler filters out rows using (pushed_cond1 AND pushed_cond2
AND ... AND pushed_condN)
or less restrictive condition, depending on handler's capabilities.
handler->ha_reset() call empties the condition stack.
Calls to rnd_init/rnd_end, index_init/index_end etc do not affect the
condition stack.
*/
virtual const COND *cond_push(const COND *cond) { return cond; };
/**
Pop the top condition from the condition stack of the handler instance.
Pops the top if condition stack, if stack is not empty.
*/
virtual void cond_pop() { return; };
/**
Push down an index condition to the handler.
The server will use this method to push down a condition it wants
the handler to evaluate when retrieving records using a specified
index. The pushed index condition will only refer to fields from
this handler that is contained in the index (but it may also refer
to fields in other handlers). Before the handler evaluates the
condition it must read the content of the index entry into the
record buffer.
The handler is free to decide if and how much of the condition it
will take responsibility for evaluating. Based on this evaluation
it should return the part of the condition it will not evaluate.
If it decides to evaluate the entire condition it should return
NULL. If it decides not to evaluate any part of the condition it
should return a pointer to the same condition as given as argument.
@param keyno the index number to evaluate the condition on
@param idx_cond the condition to be evaluated by the handler
@return The part of the pushed condition that the handler decides
not to evaluate
*/
virtual Item *idx_cond_push(uint keyno, Item* idx_cond) { return idx_cond; }
/** Reset information about pushed index conditions */
virtual void cancel_pushed_idx_cond()
{
pushed_idx_cond= NULL;
pushed_idx_cond_keyno= MAX_KEY;
in_range_check_pushed_down= false;
}
/**
Part of old, deprecated in-place ALTER API.
*/
virtual bool check_if_incompatible_data(HA_CREATE_INFO *create_info,
uint table_changes)
{ return COMPATIBLE_DATA_NO; }
/* On-line/in-place ALTER TABLE interface. */
/*
Here is an outline of on-line/in-place ALTER TABLE execution through
this interface.
Phase 1 : Initialization
========================
During this phase we determine which algorithm should be used
for execution of ALTER TABLE and what level concurrency it will
require.
*) This phase starts by opening the table and preparing description
of the new version of the table.
*) Then we check if it is impossible even in theory to carry out
this ALTER TABLE using the in-place algorithm. For example, because
we need to change storage engine or the user has explicitly requested
usage of the "copy" algorithm.
*) If in-place ALTER TABLE is theoretically possible, we continue
by compiling differences between old and new versions of the table
in the form of HA_ALTER_FLAGS bitmap. We also build a few
auxiliary structures describing requested changes and store
all these data in the Alter_inplace_info object.
*) Then the handler::check_if_supported_inplace_alter() method is called
in order to find if the storage engine can carry out changes requested
by this ALTER TABLE using the in-place algorithm. To determine this,
the engine can rely on data in HA_ALTER_FLAGS/Alter_inplace_info
passed to it as well as on its own checks. If the in-place algorithm
can be used for this ALTER TABLE, the level of required concurrency for
its execution is also returned.
If any errors occur during the handler call, ALTER TABLE is aborted
and no further handler functions are called.
*) Locking requirements of the in-place algorithm are compared to any
concurrency requirements specified by user. If there is a conflict
between them, we either switch to the copy algorithm or emit an error.
Phase 2 : Execution
===================
In this phase the operations are executed.
*) As the first step, we acquire a lock corresponding to the concurrency
level which was returned by handler::check_if_supported_inplace_alter()
and requested by the user. This lock is held for most of the
duration of in-place ALTER (if HA_ALTER_INPLACE_SHARED_LOCK_AFTER_PREPARE
or HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE were returned we acquire an
exclusive lock for duration of the next step only).
*) After that we call handler::ha_prepare_inplace_alter_table() to give the
storage engine a chance to update its internal structures with a higher
lock level than the one that will be used for the main step of algorithm.
After that we downgrade the lock if it is necessary.
*) After that, the main step of this phase and algorithm is executed.
We call the handler::ha_inplace_alter_table() method, which carries out the
changes requested by ALTER TABLE but does not makes them visible to other
connections yet.
*) We ensure that no other connection uses the table by upgrading our
lock on it to exclusive.
*) a) If the previous step succeeds, handler::ha_commit_inplace_alter_table() is
called to allow the storage engine to do any final updates to its structures,
to make all earlier changes durable and visible to other connections.
b) If we have failed to upgrade lock or any errors have occured during the
handler functions calls (including commit), we call
handler::ha_commit_inplace_alter_table()
to rollback all changes which were done during previous steps.
Phase 3 : Final
===============
In this phase we:
*) Update SQL-layer data-dictionary by installing .FRM file for the new version
of the table.
*) Inform the storage engine about this change by calling the
handler::ha_notify_table_changed() method.
*) Destroy the Alter_inplace_info and handler_ctx objects.
*/
/**
Check if a storage engine supports a particular alter table in-place
@param altered_table TABLE object for new version of table.
@param ha_alter_info Structure describing changes to be done
by ALTER TABLE and holding data used
during in-place alter.
@retval HA_ALTER_ERROR Unexpected error.
@retval HA_ALTER_INPLACE_NOT_SUPPORTED Not supported, must use copy.
@retval HA_ALTER_INPLACE_EXCLUSIVE_LOCK Supported, but requires X lock.
@retval HA_ALTER_INPLACE_SHARED_LOCK_AFTER_PREPARE
Supported, but requires SNW lock
during main phase. Prepare phase
requires X lock.
@retval HA_ALTER_INPLACE_SHARED_LOCK Supported, but requires SNW lock.
@retval HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE
Supported, concurrent reads/writes
allowed. However, prepare phase
requires X lock.
@retval HA_ALTER_INPLACE_NO_LOCK Supported, concurrent
reads/writes allowed.
@note The default implementation uses the old in-place ALTER API
to determine if the storage engine supports in-place ALTER or not.
@note Called without holding thr_lock.c lock.
*/
virtual enum_alter_inplace_result
check_if_supported_inplace_alter(TABLE *altered_table,
Alter_inplace_info *ha_alter_info);
/**
Public functions wrapping the actual handler call.
@see prepare_inplace_alter_table()
*/
bool ha_prepare_inplace_alter_table(TABLE *altered_table,
Alter_inplace_info *ha_alter_info);
/**
Public function wrapping the actual handler call.
@see inplace_alter_table()
*/
bool ha_inplace_alter_table(TABLE *altered_table,
Alter_inplace_info *ha_alter_info)
{
return inplace_alter_table(altered_table, ha_alter_info);
}
/**
Public function wrapping the actual handler call.
Allows us to enforce asserts regardless of handler implementation.
@see commit_inplace_alter_table()
*/
bool ha_commit_inplace_alter_table(TABLE *altered_table,
Alter_inplace_info *ha_alter_info,
bool commit);
/**
Public function wrapping the actual handler call.
@see notify_table_changed()
*/
void ha_notify_table_changed()
{
notify_table_changed();
}
protected:
/**
Allows the storage engine to update internal structures with concurrent
writes blocked. If check_if_supported_inplace_alter() returns
HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE or
HA_ALTER_INPLACE_SHARED_AFTER_PREPARE, this function is called with
exclusive lock otherwise the same level of locking as for
inplace_alter_table() will be used.
@note Storage engines are responsible for reporting any errors by
calling my_error()/print_error()
@note If this function reports error, commit_inplace_alter_table()
will be called with commit= false.
@note For partitioning, failing to prepare one partition, means that
commit_inplace_alter_table() will be called to roll back changes for
all partitions. This means that commit_inplace_alter_table() might be
called without prepare_inplace_alter_table() having been called first
for a given partition.
@param altered_table TABLE object for new version of table.
@param ha_alter_info Structure describing changes to be done
by ALTER TABLE and holding data used
during in-place alter.
@retval true Error
@retval false Success
*/
virtual bool prepare_inplace_alter_table(TABLE *altered_table,
Alter_inplace_info *ha_alter_info)
{ return false; }
/**
Alter the table structure in-place with operations specified using HA_ALTER_FLAGS
and Alter_inplace_info. The level of concurrency allowed during this
operation depends on the return value from check_if_supported_inplace_alter().
@note Storage engines are responsible for reporting any errors by
calling my_error()/print_error()
@note If this function reports error, commit_inplace_alter_table()
will be called with commit= false.
@param altered_table TABLE object for new version of table.
@param ha_alter_info Structure describing changes to be done
by ALTER TABLE and holding data used
during in-place alter.
@retval true Error
@retval false Success
*/
virtual bool inplace_alter_table(TABLE *altered_table,
Alter_inplace_info *ha_alter_info)
{ return false; }
/**
Commit or rollback the changes made during prepare_inplace_alter_table()
and inplace_alter_table() inside the storage engine.
Note that in case of rollback the allowed level of concurrency during
this operation will be the same as for inplace_alter_table() and thus
might be higher than during prepare_inplace_alter_table(). (For example,
concurrent writes were blocked during prepare, but might not be during
rollback).
@note Storage engines are responsible for reporting any errors by
calling my_error()/print_error()
@note If this function with commit= true reports error, it will be called
again with commit= false.
@note In case of partitioning, this function might be called for rollback
without prepare_inplace_alter_table() having been called first.
Also partitioned tables sets ha_alter_info->group_commit_ctx to a NULL
terminated array of the partitions handlers and if all of them are
committed as one, then group_commit_ctx should be set to NULL to indicate
to the partitioning handler that all partitions handlers are committed.
@see prepare_inplace_alter_table().
@param altered_table TABLE object for new version of table.
@param ha_alter_info Structure describing changes to be done
by ALTER TABLE and holding data used
during in-place alter.
@param commit True => Commit, False => Rollback.
@retval true Error
@retval false Success
*/
virtual bool commit_inplace_alter_table(TABLE *altered_table,
Alter_inplace_info *ha_alter_info,
bool commit)
{
/* Nothing to commit/rollback, mark all handlers committed! */
ha_alter_info->group_commit_ctx= NULL;
return false;
}
/**
Notify the storage engine that the table structure (.FRM) has been updated.
@note No errors are allowed during notify_table_changed().
*/
virtual void notify_table_changed();
public:
/* End of On-line/in-place ALTER TABLE interface. */
/**
use_hidden_primary_key() is called in case of an update/delete when
(table_flags() and HA_PRIMARY_KEY_REQUIRED_FOR_DELETE) is defined
but we don't have a primary key
*/
virtual void use_hidden_primary_key();
virtual uint alter_table_flags(uint flags)
{
if (ht->alter_table_flags)
return ht->alter_table_flags(flags);
return 0;
}
LEX_STRING *engine_name() { return hton_name(ht); }
/*
@brief
Check whether the engine supports virtual columns
@retval
FALSE if the engine does not support virtual columns
@retval
TRUE if the engine supports virtual columns
*/
virtual bool check_if_supported_virtual_columns(void) { return FALSE;}
TABLE* get_table() { return table; }
TABLE_SHARE* get_table_share() { return table_share; }
protected:
/* deprecated, don't use in new engines */
inline void ha_statistic_increment(ulong SSV::*offset) const { }
/* Service methods for use by storage engines. */
void **ha_data(THD *) const;
THD *ha_thd(void) const;
/**
Acquire the instrumented table information from a table share.
@return an instrumented table share, or NULL.
*/
PSI_table_share *ha_table_share_psi() const;
/**
Default rename_table() and delete_table() rename/delete files with a
given name and extensions from bas_ext().
These methods can be overridden, but their default implementation
provide useful functionality.
*/
virtual int rename_table(const char *from, const char *to);
/**
Delete a table in the engine. Called for base as well as temporary
tables.
*/
virtual int delete_table(const char *name);
private:
/* Private helpers */
inline void mark_trx_read_write();
private:
inline void increment_statistics(ulong SSV::*offset) const;
inline void decrement_statistics(ulong SSV::*offset) const;
/*
Low-level primitives for storage engines. These should be
overridden by the storage engine class. To call these methods, use
the corresponding 'ha_*' method above.
*/
virtual int open(const char *name, int mode, uint test_if_locked)=0;
/* Note: ha_index_read_idx_map() may bypass index_init() */
virtual int index_init(uint idx, bool sorted) { return 0; }
virtual int index_end() { return 0; }
/**
rnd_init() can be called two times without rnd_end() in between
(it only makes sense if scan=1).
then the second call should prepare for the new table scan (e.g
if rnd_init allocates the cursor, second call should position it
to the start of the table, no need to deallocate and allocate it again
*/
virtual int rnd_init(bool scan)= 0;
virtual int rnd_end() { return 0; }
virtual int write_row(uchar *buf __attribute__((unused)))
{
return HA_ERR_WRONG_COMMAND;
}
/**
Update a single row.
Note: If HA_ERR_FOUND_DUPP_KEY is returned, the handler must read
all columns of the row so MySQL can create an error message. If
the columns required for the error message are not read, the error
message will contain garbage.
*/
virtual int update_row(const uchar *old_data __attribute__((unused)),
uchar *new_data __attribute__((unused)))
{
return HA_ERR_WRONG_COMMAND;
}
virtual int delete_row(const uchar *buf __attribute__((unused)))
{
return HA_ERR_WRONG_COMMAND;
}
/**
Reset state of file to after 'open'.
This function is called after every statement for all tables used
by that statement.
*/
virtual int reset() { return 0; }
virtual Table_flags table_flags(void) const= 0;
/**
Is not invoked for non-transactional temporary tables.
Tells the storage engine that we intend to read or write data
from the table. This call is prefixed with a call to handler::store_lock()
and is invoked only for those handler instances that stored the lock.
Calls to rnd_init/index_init are prefixed with this call. When table
IO is complete, we call external_lock(F_UNLCK).
A storage engine writer should expect that each call to
::external_lock(F_[RD|WR]LOCK is followed by a call to
::external_lock(F_UNLCK). If it is not, it is a bug in MySQL.
The name and signature originate from the first implementation
in MyISAM, which would call fcntl to set/clear an advisory
lock on the data file in this method.
@param lock_type F_RDLCK, F_WRLCK, F_UNLCK
@return non-0 in case of failure, 0 in case of success.
When lock_type is F_UNLCK, the return value is ignored.
*/
virtual int external_lock(THD *thd __attribute__((unused)),
int lock_type __attribute__((unused)))
{
return 0;
}
virtual void release_auto_increment() { return; };
/** admin commands - called from mysql_admin_table */
virtual int check_for_upgrade(HA_CHECK_OPT *check_opt)
{ return 0; }
virtual int check(THD* thd, HA_CHECK_OPT* check_opt)
{ return HA_ADMIN_NOT_IMPLEMENTED; }
/**
In this method check_opt can be modified
to specify CHECK option to use to call check()
upon the table.
*/
virtual int repair(THD* thd, HA_CHECK_OPT* check_opt)
{
DBUG_ASSERT(!(ha_table_flags() & HA_CAN_REPAIR));
return HA_ADMIN_NOT_IMPLEMENTED;
}
virtual void start_bulk_insert(ha_rows rows, uint flags) {}
virtual int end_bulk_insert() { return 0; }
protected:
virtual int index_read(uchar * buf, const uchar * key, uint key_len,
enum ha_rkey_function find_flag)
{ return HA_ERR_WRONG_COMMAND; }
friend class ha_partition;
public:
/**
This method is similar to update_row, however the handler doesn't need
to execute the updates at this point in time. The handler can be certain
that another call to bulk_update_row will occur OR a call to
exec_bulk_update before the set of updates in this query is concluded.
@param old_data Old record
@param new_data New record
@param dup_key_found Number of duplicate keys found
@retval 0 Bulk delete used by handler
@retval 1 Bulk delete not used, normal operation used
*/
virtual int bulk_update_row(const uchar *old_data, uchar *new_data,
uint *dup_key_found)
{
DBUG_ASSERT(FALSE);
return HA_ERR_WRONG_COMMAND;
}
/**
This is called to delete all rows in a table
If the handler don't support this, then this function will
return HA_ERR_WRONG_COMMAND and MySQL will delete the rows one
by one.
*/
virtual int delete_all_rows()
{ return (my_errno=HA_ERR_WRONG_COMMAND); }
/**
Quickly remove all rows from a table.
@remark This method is responsible for implementing MySQL's TRUNCATE
TABLE statement, which is a DDL operation. As such, a engine
can bypass certain integrity checks and in some cases avoid
fine-grained locking (e.g. row locks) which would normally be
required for a DELETE statement.
@remark Typically, truncate is not used if it can result in integrity
violation. For example, truncate is not used when a foreign
key references the table, but it might be used if foreign key
checks are disabled.
@remark Engine is responsible for resetting the auto-increment counter.
@remark The table is locked in exclusive mode.
*/
virtual int truncate()
{
int error= delete_all_rows();
return error ? error : reset_auto_increment(0);
}
/**
Reset the auto-increment counter to the given value, i.e. the next row
inserted will get the given value.
*/
virtual int reset_auto_increment(ulonglong value)
{ return 0; }
virtual int optimize(THD* thd, HA_CHECK_OPT* check_opt)
{ return HA_ADMIN_NOT_IMPLEMENTED; }
virtual int analyze(THD* thd, HA_CHECK_OPT* check_opt)
{ return HA_ADMIN_NOT_IMPLEMENTED; }
virtual bool check_and_repair(THD *thd) { return TRUE; }
virtual int disable_indexes(uint mode) { return HA_ERR_WRONG_COMMAND; }
virtual int enable_indexes(uint mode) { return HA_ERR_WRONG_COMMAND; }
virtual int discard_or_import_tablespace(my_bool discard)
{ return (my_errno=HA_ERR_WRONG_COMMAND); }
virtual void prepare_for_alter() { return; }
virtual void drop_table(const char *name);
virtual int create(const char *name, TABLE *form, HA_CREATE_INFO *info)=0;
virtual int create_partitioning_metadata(const char *name, const char *old_name,
int action_flag)
{ return FALSE; }
virtual int change_partitions(HA_CREATE_INFO *create_info,
const char *path,
ulonglong * const copied,
ulonglong * const deleted,
const uchar *pack_frm_data,
size_t pack_frm_len)
{ return HA_ERR_WRONG_COMMAND; }
virtual int drop_partitions(const char *path)
{ return HA_ERR_WRONG_COMMAND; }
virtual int rename_partitions(const char *path)
{ return HA_ERR_WRONG_COMMAND; }
virtual bool set_ha_share_ref(Handler_share **arg_ha_share)
{
DBUG_ASSERT(!ha_share);
DBUG_ASSERT(arg_ha_share);
if (ha_share || !arg_ha_share)
return true;
ha_share= arg_ha_share;
return false;
}
int get_lock_type() const { return m_lock_type; }
public:
/* XXX to be removed, see ha_partition::partition_ht() */
virtual handlerton *partition_ht() const
{ return ht; }
inline int ha_write_tmp_row(uchar *buf);
inline int ha_update_tmp_row(const uchar * old_data, uchar * new_data);
virtual void set_lock_type(enum thr_lock_type lock);
friend enum icp_result handler_index_cond_check(void* h_arg);
protected:
Handler_share *get_ha_share_ptr();
void set_ha_share_ptr(Handler_share *arg_ha_share);
void lock_shared_ha_data();
void unlock_shared_ha_data();
};
#include "multi_range_read.h"
bool key_uses_partial_cols(TABLE_SHARE *table, uint keyno);
/* Some extern variables used with handlers */
extern const char *ha_row_type[];
extern MYSQL_PLUGIN_IMPORT const char *tx_isolation_names[];
extern MYSQL_PLUGIN_IMPORT const char *binlog_format_names[];
extern TYPELIB tx_isolation_typelib;
extern const char *myisam_stats_method_names[];
extern ulong total_ha, total_ha_2pc;
/* lookups */
plugin_ref ha_resolve_by_name(THD *thd, const LEX_STRING *name, bool tmp_table);
plugin_ref ha_lock_engine(THD *thd, const handlerton *hton);
handlerton *ha_resolve_by_legacy_type(THD *thd, enum legacy_db_type db_type);
handler *get_new_handler(TABLE_SHARE *share, MEM_ROOT *alloc,
handlerton *db_type);
handlerton *ha_checktype(THD *thd, handlerton *hton, bool no_substitute);
static inline handlerton *ha_checktype(THD *thd, enum legacy_db_type type,
bool no_substitute = 0)
{
return ha_checktype(thd, ha_resolve_by_legacy_type(thd, type), no_substitute);
}
static inline enum legacy_db_type ha_legacy_type(const handlerton *db_type)
{
return (db_type == NULL) ? DB_TYPE_UNKNOWN : db_type->db_type;
}
static inline const char *ha_resolve_storage_engine_name(const handlerton *db_type)
{
return db_type == NULL ? "UNKNOWN" : hton_name(db_type)->str;
}
static inline bool ha_check_storage_engine_flag(const handlerton *db_type, uint32 flag)
{
return db_type == NULL ? FALSE : MY_TEST(db_type->flags & flag);
}
static inline bool ha_storage_engine_is_enabled(const handlerton *db_type)
{
return (db_type && db_type->create) ?
(db_type->state == SHOW_OPTION_YES) : FALSE;
}
#define view_pseudo_hton ((handlerton *)1)
/* basic stuff */
int ha_init_errors(void);
int ha_init(void);
int ha_end(void);
int ha_initialize_handlerton(st_plugin_int *plugin);
int ha_finalize_handlerton(st_plugin_int *plugin);
TYPELIB *ha_known_exts(void);
int ha_panic(enum ha_panic_function flag);
void ha_close_connection(THD* thd);
void ha_kill_query(THD* thd, enum thd_kill_levels level);
bool ha_flush_logs(handlerton *db_type);
void ha_drop_database(char* path);
void ha_checkpoint_state(bool disable);
void ha_commit_checkpoint_request(void *cookie, void (*pre_hook)(void *));
int ha_create_table(THD *thd, const char *path,
const char *db, const char *table_name,
HA_CREATE_INFO *create_info, LEX_CUSTRING *frm);
int ha_delete_table(THD *thd, handlerton *db_type, const char *path,
const char *db, const char *alias, bool generate_warning);
/* statistics and info */
bool ha_show_status(THD *thd, handlerton *db_type, enum ha_stat_type stat);
/* discovery */
#ifdef MYSQL_SERVER
class Discovered_table_list: public handlerton::discovered_list
{
THD *thd;
const char *wild, *wend;
bool with_temps; // whether to include temp tables in the result
public:
Dynamic_array<LEX_STRING*> *tables;
Discovered_table_list(THD *thd_arg, Dynamic_array<LEX_STRING*> *tables_arg,
const LEX_STRING *wild_arg);
Discovered_table_list(THD *thd_arg, Dynamic_array<LEX_STRING*> *tables_arg)
: thd(thd_arg), wild(NULL), with_temps(true), tables(tables_arg) {}
~Discovered_table_list() {}
bool add_table(const char *tname, size_t tlen);
bool add_file(const char *fname);
void sort();
void remove_duplicates(); // assumes that the list is sorted
};
int ha_discover_table(THD *thd, TABLE_SHARE *share);
int ha_discover_table_names(THD *thd, LEX_STRING *db, MY_DIR *dirp,
Discovered_table_list *result, bool reusable);
bool ha_table_exists(THD *thd, const char *db, const char *table_name,
handlerton **hton= 0);
#endif
/* key cache */
extern "C" int ha_init_key_cache(const char *name, KEY_CACHE *key_cache, void *);
int ha_resize_key_cache(KEY_CACHE *key_cache);
int ha_change_key_cache_param(KEY_CACHE *key_cache);
int ha_repartition_key_cache(KEY_CACHE *key_cache);
int ha_change_key_cache(KEY_CACHE *old_key_cache, KEY_CACHE *new_key_cache);
/* report to InnoDB that control passes to the client */
int ha_release_temporary_latches(THD *thd);
/* transactions: interface to handlerton functions */
int ha_start_consistent_snapshot(THD *thd);
int ha_commit_or_rollback_by_xid(XID *xid, bool commit);
int ha_commit_one_phase(THD *thd, bool all);
int ha_commit_trans(THD *thd, bool all);
int ha_rollback_trans(THD *thd, bool all);
int ha_prepare(THD *thd);
int ha_recover(HASH *commit_list);
/* transactions: these functions never call handlerton functions directly */
int ha_enable_transaction(THD *thd, bool on);
/* savepoints */
int ha_rollback_to_savepoint(THD *thd, SAVEPOINT *sv);
bool ha_rollback_to_savepoint_can_release_mdl(THD *thd);
int ha_savepoint(THD *thd, SAVEPOINT *sv);
int ha_release_savepoint(THD *thd, SAVEPOINT *sv);
#ifdef WITH_WSREP
int ha_abort_transaction(THD *bf_thd, THD *victim_thd, my_bool signal);
void ha_fake_trx_id(THD *thd);
#else
inline void ha_fake_trx_id(THD *thd) { }
#endif
/* these are called by storage engines */
void trans_register_ha(THD *thd, bool all, handlerton *ht);
/*
Storage engine has to assume the transaction will end up with 2pc if
- there is more than one 2pc-capable storage engine available
- in the current transaction 2pc was not disabled yet
*/
#define trans_need_2pc(thd, all) ((total_ha_2pc > 1) && \
!((all ? &thd->transaction.all : &thd->transaction.stmt)->no_2pc))
const char *get_canonical_filename(handler *file, const char *path,
char *tmp_path);
bool mysql_xa_recover(THD *thd);
void commit_checkpoint_notify_ha(handlerton *hton, void *cookie);
inline const char *table_case_name(HA_CREATE_INFO *info, const char *name)
{
return ((lower_case_table_names == 2 && info->alias) ? info->alias : name);
}
#define TABLE_IO_WAIT(TRACKER, PSI, OP, INDEX, FLAGS, PAYLOAD) \
{ \
Exec_time_tracker *this_tracker; \
if (unlikely((this_tracker= tracker))) \
tracker->start_tracking(); \
\
MYSQL_TABLE_IO_WAIT(PSI, OP, INDEX, FLAGS, PAYLOAD); \
\
if (unlikely(this_tracker)) \
tracker->stop_tracking(); \
}
void print_keydup_error(TABLE *table, KEY *key, const char *msg, myf errflag);
void print_keydup_error(TABLE *table, KEY *key, myf errflag);
#endif
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