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Diffstat (limited to 'sql/handler.h')
| -rw-r--r-- | sql/handler.h | 5426 |
1 files changed, 5426 insertions, 0 deletions
diff --git a/sql/handler.h b/sql/handler.h new file mode 100644 index 00000000..50ec0ed1 --- /dev/null +++ b/sql/handler.h @@ -0,0 +1,5426 @@ +#ifndef HANDLER_INCLUDED +#define HANDLER_INCLUDED +/* + Copyright (c) 2000, 2019, Oracle and/or its affiliates. + Copyright (c) 2009, 2023, MariaDB + + 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 02110-1335 USA +*/ + +/* Definitions for parameters to do with handler-routines */ + +#ifdef USE_PRAGMA_INTERFACE +#pragma interface /* gcc class implementation */ +#endif + +#include "sql_const.h" +#include "sql_basic_types.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 "vers_string.h" +#include "ha_handler_stats.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> +#include "sql_sequence.h" +#include "mem_root_array.h" +#include <utility> // pair +#include <my_attribute.h> /* __attribute__ */ + +class Alter_info; +class Virtual_column_info; +class sequence_definition; +class Rowid_filter; +class Field_string; +class Field_varstring; +class Field_blob; +class Column_definition; + +// 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 +#define HA_ADMIN_COMMIT_ERROR -13 + +/** + 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_COPY_NO_LOCK, + HA_ALTER_INPLACE_COPY_LOCK, + HA_ALTER_INPLACE_NOCOPY_LOCK, + HA_ALTER_INPLACE_NOCOPY_NO_LOCK, + HA_ALTER_INPLACE_INSTANT, + HA_ALTER_INPLACE_NOT_SUPPORTED, + HA_ALTER_INPLACE_EXCLUSIVE_LOCK, + HA_ALTER_INPLACE_SHARED_LOCK, + HA_ALTER_INPLACE_NO_LOCK +}; + +/* Flags for create_partitioning_metadata() */ + +enum chf_create_flags { + CHF_CREATE_FLAG, + CHF_DELETE_FLAG, + CHF_RENAME_FLAG, + CHF_INDEX_FLAG +}; + +/* 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 */ +/* + The engine requires every table to have a user-specified PRIMARY KEY. + Do not set the flag if the engine can generate a hidden primary key internally. + This flag is ignored if a SEQUENCE is created (which, in turn, needs + HA_CAN_TABLES_WITHOUT_ROLLBACK flag) +*/ +#define HA_REQUIRE_PRIMARY_KEY (1ULL << 12) +#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) /* unused */ +/* + 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_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) +/* All of VARCHAR is stored, including bytes after real varchar data */ +#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 + number 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 (1ULL << 43) + +/* + Engine supports extended fulltext API + */ +#define HA_CAN_FULLTEXT_EXT (1ULL << 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 (1ULL << 45) + +/* + Storage engine does not require an exclusive metadata lock + on the table during optimize. (TODO and repair?). + It can allow other connections to open the table. + (it does not necessarily mean that other connections can + read or modify the table - this is defined by THR locks and the + ::store_lock() method). +*/ +#define HA_CONCURRENT_OPTIMIZE (1ULL << 46) + +/* + If the storage engine support tables that will not roll back on commit + In addition the table should not lock rows and support READ and WRITE + UNCOMMITTED. + This is useful for implementing things like SEQUENCE but can also in + the future be useful to do logging that should never roll back. +*/ +#define HA_CAN_TABLES_WITHOUT_ROLLBACK (1ULL << 47) + +/* + Mainly for usage by SEQUENCE engine. Setting this flag means + that the table will never roll back and that all operations + for this table should stored in the non transactional log + space that will always be written, even on rollback. +*/ + +#define HA_PERSISTENT_TABLE (1ULL << 48) + +/* + If storage engine uses another engine as a base + This flag is also needed if the table tries to open the .frm file + as part of drop table. +*/ +#define HA_REUSES_FILE_NAMES (1ULL << 49) + +/* + Set of all binlog flags. Currently only contain the capabilities + flags. + */ +#define HA_BINLOG_FLAGS (HA_BINLOG_ROW_CAPABLE | HA_BINLOG_STMT_CAPABLE) + +/* The following are used by Spider */ +#define HA_CAN_FORCE_BULK_UPDATE (1ULL << 50) +#define HA_CAN_FORCE_BULK_DELETE (1ULL << 51) +#define HA_CAN_DIRECT_UPDATE_AND_DELETE (1ULL << 52) + +/* The following is for partition handler */ +#define HA_CAN_MULTISTEP_MERGE (1LL << 53) + +/* calling cmp_ref() on the engine is expensive */ +#define HA_SLOW_CMP_REF (1ULL << 54) +#define HA_CMP_REF_IS_EXPENSIVE HA_SLOW_CMP_REF + +/** + Some engines are unable to provide an efficient implementation for rnd_pos(). + Server will try to avoid it, if possible + + TODO better to do it with cost estimates, not with an explicit flag +*/ +#define HA_SLOW_RND_POS (1ULL << 55) + +/* Safe for online backup */ +#define HA_CAN_ONLINE_BACKUPS (1ULL << 56) + +/* Support native hash index */ +#define HA_CAN_HASH_KEYS (1ULL << 57) +#define HA_CRASH_SAFE (1ULL << 58) + +/* + There is no need to evict the table from the table definition cache having + run ANALYZE TABLE on it + */ +#define HA_ONLINE_ANALYZE (1ULL << 59) +/* + Rowid's are not comparable. This is set if the rowid is unique to the + current open handler, like it is with federated where the rowid is a + pointer to a local result set buffer. The effect of having this set is + that the optimizer will not consider the following optimizations for + the table: + ror scans, filtering or duplicate weedout +*/ +#define HA_NON_COMPARABLE_ROWID (1ULL << 60) + +/* Implements SELECT ... FOR UPDATE SKIP LOCKED */ +#define HA_CAN_SKIP_LOCKED (1ULL << 61) + +#define HA_LAST_TABLE_FLAG HA_CAN_SKIP_LOCKED + + +/* 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 + +#define HA_DO_RANGE_FILTER_PUSHDOWN 1024 + +/* + 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 (1UL << 0) +#define HA_INPLACE_DROP_INDEX_NO_READ_WRITE (1UL << 1) +#define HA_INPLACE_ADD_UNIQUE_INDEX_NO_READ_WRITE (1UL << 2) +#define HA_INPLACE_DROP_UNIQUE_INDEX_NO_READ_WRITE (1UL << 3) +#define HA_INPLACE_ADD_PK_INDEX_NO_READ_WRITE (1UL << 4) +#define HA_INPLACE_DROP_PK_INDEX_NO_READ_WRITE (1UL << 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 (1UL << 6) +#define HA_INPLACE_DROP_INDEX_NO_WRITE (1UL << 7) +#define HA_INPLACE_ADD_UNIQUE_INDEX_NO_WRITE (1UL << 8) +#define HA_INPLACE_DROP_UNIQUE_INDEX_NO_WRITE (1UL << 9) +#define HA_INPLACE_ADD_PK_INDEX_NO_WRITE (1UL << 10) +#define HA_INPLACE_DROP_PK_INDEX_NO_WRITE (1UL << 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 (1UL << 12) +#define HA_FAST_CHANGE_PARTITION (1UL << 13) +#define HA_PARTITION_ONE_PHASE (1UL << 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 1U +#define HA_READ_ONLY 16U /* File opened as readonly */ +/* Try readonly if can't open with read and write */ +#define HA_TRY_READ_ONLY 32U + + /* Some key definitions */ +#define HA_KEY_NULL_LENGTH 1 +#define HA_KEY_BLOB_LENGTH 2 + +/* Maximum length of any index lookup key, in bytes */ + +#define MAX_KEY_LENGTH (MAX_DATA_LENGTH_FOR_KEY \ + +(MAX_REF_PARTS \ + *(HA_KEY_NULL_LENGTH + HA_KEY_BLOB_LENGTH))) + +#define HA_LEX_CREATE_TMP_TABLE 1U +#define HA_CREATE_TMP_ALTER 8U +#define HA_LEX_CREATE_SEQUENCE 16U +#define HA_VERSIONED_TABLE 32U +#define HA_SKIP_KEY_SORT 64U + +#define HA_MAX_REC_LENGTH 65535 + +/* Table caching type */ +#define HA_CACHE_TBL_NONTRANSACT 0 +#define HA_CACHE_TBL_NOCACHE 1U +#define HA_CACHE_TBL_ASKTRANSACT 2U +#define HA_CACHE_TBL_TRANSACT 4U + +/** + 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 1U +#define HA_CHECK_DUP_UNIQUE 2U +#define HA_CHECK_FK_ERROR 4U +#define HA_CHECK_DUP (HA_CHECK_DUP_KEY + HA_CHECK_DUP_UNIQUE) +#define HA_CHECK_ALL (~0U) + +/* Options for info_push() */ +#define INFO_KIND_UPDATE_FIELDS 101 +#define INFO_KIND_UPDATE_VALUES 102 +#define INFO_KIND_FORCE_LIMIT_BEGIN 103 +#define INFO_KIND_FORCE_LIMIT_END 104 + +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_S3=41, + DB_TYPE_ARIA=42, + DB_TYPE_TOKUDB=43, /* disabled in MariaDB Server 10.5, removed in 10.6 */ + DB_TYPE_SEQUENCE=44, + DB_TYPE_FIRST_DYNAMIC=45, + 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 (1UL << 0) +#define HA_CREATE_USED_RAID (1UL << 1) //RAID is no longer available +#define HA_CREATE_USED_UNION (1UL << 2) +#define HA_CREATE_USED_INSERT_METHOD (1UL << 3) +#define HA_CREATE_USED_MIN_ROWS (1UL << 4) +#define HA_CREATE_USED_MAX_ROWS (1UL << 5) +#define HA_CREATE_USED_AVG_ROW_LENGTH (1UL << 6) +#define HA_CREATE_USED_PACK_KEYS (1UL << 7) +#define HA_CREATE_USED_CHARSET (1UL << 8) +#define HA_CREATE_USED_DEFAULT_CHARSET (1UL << 9) +#define HA_CREATE_USED_DATADIR (1UL << 10) +#define HA_CREATE_USED_INDEXDIR (1UL << 11) +#define HA_CREATE_USED_ENGINE (1UL << 12) +#define HA_CREATE_USED_CHECKSUM (1UL << 13) +#define HA_CREATE_USED_DELAY_KEY_WRITE (1UL << 14) +#define HA_CREATE_USED_ROW_FORMAT (1UL << 15) +#define HA_CREATE_USED_COMMENT (1UL << 16) +#define HA_CREATE_USED_PASSWORD (1UL << 17) +#define HA_CREATE_USED_CONNECTION (1UL << 18) +#define HA_CREATE_USED_KEY_BLOCK_SIZE (1UL << 19) +/* The following two are used by Maria engine: */ +#define HA_CREATE_USED_TRANSACTIONAL (1UL << 20) +#define HA_CREATE_USED_PAGE_CHECKSUM (1UL << 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 (1UL << 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 (1UL << 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 (1UL << 24) + +/* Create a sequence */ +#define HA_CREATE_USED_SEQUENCE (1UL << 25) +/* Tell binlog_show_create_table to print all engine options */ +#define HA_CREATE_PRINT_ALL_OPTIONS (1UL << 26) + +typedef ulonglong alter_table_operations; +typedef bool Log_func(THD*, TABLE*, bool, const uchar*, const uchar*); + +/* + These flags are set by the parser and describes the type of + operation(s) specified by the ALTER TABLE statement. +*/ + +// Set by parser for ADD [COLUMN] +#define ALTER_PARSER_ADD_COLUMN (1ULL << 0) +// Set by parser for DROP [COLUMN] +#define ALTER_PARSER_DROP_COLUMN (1ULL << 1) +// Set for CHANGE [COLUMN] | MODIFY [CHANGE] & mysql_recreate_table +#define ALTER_CHANGE_COLUMN (1ULL << 2) +// Set for ADD INDEX | ADD KEY | ADD PRIMARY KEY | ADD UNIQUE KEY | +// ADD UNIQUE INDEX | ALTER ADD [COLUMN] +#define ALTER_ADD_INDEX (1ULL << 3) +// Set for DROP PRIMARY KEY | DROP FOREIGN KEY | DROP KEY | DROP INDEX +#define ALTER_DROP_INDEX (1ULL << 4) +// Set for RENAME [TO] +#define ALTER_RENAME (1ULL << 5) +// Set for ORDER BY +#define ALTER_ORDER (1ULL << 6) +// Set for table_options, like table comment +#define ALTER_OPTIONS (1ULL << 7) +// Set for ALTER [COLUMN] ... SET DEFAULT ... | DROP DEFAULT +#define ALTER_CHANGE_COLUMN_DEFAULT (1ULL << 8) +// Set for DISABLE KEYS | ENABLE KEYS +#define ALTER_KEYS_ONOFF (1ULL << 9) +// Set for FORCE, ENGINE(same engine), by mysql_recreate_table() +#define ALTER_RECREATE (1ULL << 10) +// Set for CONVERT TO +#define ALTER_CONVERT_TO (1ULL << 11) +// Set for DROP ... ADD some_index +#define ALTER_RENAME_INDEX (1ULL << 12) +// Set for ADD FOREIGN KEY +#define ALTER_ADD_FOREIGN_KEY (1ULL << 21) +// Set for DROP FOREIGN KEY +#define ALTER_DROP_FOREIGN_KEY (1ULL << 22) +#define ALTER_CHANGE_INDEX_COMMENT (1ULL << 23) +// Set for ADD [COLUMN] FIRST | AFTER +#define ALTER_COLUMN_ORDER (1ULL << 25) +#define ALTER_ADD_CHECK_CONSTRAINT (1ULL << 27) +#define ALTER_DROP_CHECK_CONSTRAINT (1ULL << 28) +#define ALTER_RENAME_COLUMN (1ULL << 29) +#define ALTER_COLUMN_UNVERSIONED (1ULL << 30) +#define ALTER_ADD_SYSTEM_VERSIONING (1ULL << 31) +#define ALTER_DROP_SYSTEM_VERSIONING (1ULL << 32) +#define ALTER_ADD_PERIOD (1ULL << 33) +#define ALTER_DROP_PERIOD (1ULL << 34) + +/* + Following defines are used by ALTER_INPLACE_TABLE + + They do describe in more detail the type operation(s) to be executed + by the storage engine. For example, which type of type of index to be + added/dropped. These are set by fill_alter_inplace_info(). +*/ + +#define ALTER_RECREATE_TABLE ALTER_RECREATE +#define ALTER_CHANGE_CREATE_OPTION ALTER_OPTIONS +#define ALTER_ADD_COLUMN (ALTER_ADD_VIRTUAL_COLUMN | \ + ALTER_ADD_STORED_BASE_COLUMN | \ + ALTER_ADD_STORED_GENERATED_COLUMN) +#define ALTER_DROP_COLUMN (ALTER_DROP_VIRTUAL_COLUMN | \ + ALTER_DROP_STORED_COLUMN) +#define ALTER_COLUMN_DEFAULT ALTER_CHANGE_COLUMN_DEFAULT + +// Add non-unique, non-primary index +#define ALTER_ADD_NON_UNIQUE_NON_PRIM_INDEX (1ULL << 35) + +// Drop non-unique, non-primary index +#define ALTER_DROP_NON_UNIQUE_NON_PRIM_INDEX (1ULL << 36) + +// Add unique, non-primary index +#define ALTER_ADD_UNIQUE_INDEX (1ULL << 37) + +// Drop unique, non-primary index +#define ALTER_DROP_UNIQUE_INDEX (1ULL << 38) + +// Add primary index +#define ALTER_ADD_PK_INDEX (1ULL << 39) + +// Drop primary index +#define ALTER_DROP_PK_INDEX (1ULL << 40) + +// Virtual generated column +#define ALTER_ADD_VIRTUAL_COLUMN (1ULL << 41) +// Stored base (non-generated) column +#define ALTER_ADD_STORED_BASE_COLUMN (1ULL << 42) +// Stored generated column +#define ALTER_ADD_STORED_GENERATED_COLUMN (1ULL << 43) + +// Drop column +#define ALTER_DROP_VIRTUAL_COLUMN (1ULL << 44) +#define ALTER_DROP_STORED_COLUMN (1ULL << 45) + +// Rename column (verified; ALTER_RENAME_COLUMN may use original name) +#define ALTER_COLUMN_NAME (1ULL << 46) + +// Change column datatype +#define ALTER_VIRTUAL_COLUMN_TYPE (1ULL << 47) +#define ALTER_STORED_COLUMN_TYPE (1ULL << 48) + + +// Engine can handle type change by itself in ALGORITHM=INPLACE +#define ALTER_COLUMN_TYPE_CHANGE_BY_ENGINE (1ULL << 49) + +// Reorder column +#define ALTER_STORED_COLUMN_ORDER (1ULL << 50) + +// Reorder column +#define ALTER_VIRTUAL_COLUMN_ORDER (1ULL << 51) + +// Change column from NOT NULL to NULL +#define ALTER_COLUMN_NULLABLE (1ULL << 52) + +// Change column from NULL to NOT NULL +#define ALTER_COLUMN_NOT_NULLABLE (1ULL << 53) + +// Change column generation expression +#define ALTER_VIRTUAL_GCOL_EXPR (1ULL << 54) +#define ALTER_STORED_GCOL_EXPR (1ULL << 55) + +// column's engine options changed, something in field->option_struct +#define ALTER_COLUMN_OPTION (1ULL << 56) + +// MySQL alias for the same thing: +#define ALTER_COLUMN_STORAGE_TYPE ALTER_COLUMN_OPTION + +// Change the column format of column +#define ALTER_COLUMN_COLUMN_FORMAT (1ULL << 57) + +/** + Changes in generated columns that affect storage, + for example, when a vcol type or expression changes + and this vcol is indexed or used in a partitioning expression +*/ +#define ALTER_COLUMN_VCOL (1ULL << 58) + +/** + ALTER TABLE for a partitioned table. The engine needs to commit + online alter of all partitions atomically (using group_commit_ctx) +*/ +#define ALTER_PARTITIONED (1ULL << 59) + +/** + Change in index length such that it doesn't require index rebuild. +*/ +#define ALTER_COLUMN_INDEX_LENGTH (1ULL << 60) + +/** + Indicate that index order might have been changed. Disables inplace algorithm + by default (not for InnoDB). +*/ +#define ALTER_INDEX_ORDER (1ULL << 61) + +/** + Means that the ignorability of an index is changed. +*/ +#define ALTER_INDEX_IGNORABILITY (1ULL << 62) + +/* + Flags set in partition_flags when altering partitions +*/ + +// Set for ADD PARTITION +#define ALTER_PARTITION_ADD (1ULL << 1) +// Set for DROP PARTITION +#define ALTER_PARTITION_DROP (1ULL << 2) +// Set for COALESCE PARTITION +#define ALTER_PARTITION_COALESCE (1ULL << 3) +// Set for REORGANIZE PARTITION ... INTO +#define ALTER_PARTITION_REORGANIZE (1ULL << 4) +// Set for partition_options +#define ALTER_PARTITION_INFO (1ULL << 5) +// Set for LOAD INDEX INTO CACHE ... PARTITION +// Set for CACHE INDEX ... PARTITION +#define ALTER_PARTITION_ADMIN (1ULL << 6) +// Set for REBUILD PARTITION +#define ALTER_PARTITION_REBUILD (1ULL << 7) +// Set for partitioning operations specifying ALL keyword +#define ALTER_PARTITION_ALL (1ULL << 8) +// Set for REMOVE PARTITIONING +#define ALTER_PARTITION_REMOVE (1ULL << 9) +// Set for EXCHANGE PARITION +#define ALTER_PARTITION_EXCHANGE (1ULL << 10) +// Set by Sql_cmd_alter_table_truncate_partition::execute() +#define ALTER_PARTITION_TRUNCATE (1ULL << 11) +// Set for REORGANIZE PARTITION +#define ALTER_PARTITION_TABLE_REORG (1ULL << 12) +#define ALTER_PARTITION_CONVERT_IN (1ULL << 13) +#define ALTER_PARTITION_CONVERT_OUT (1ULL << 14) +// Set for vers_add_auto_hist_parts() operation +#define ALTER_PARTITION_AUTO_HIST (1ULL << 15) + +/* + 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() = default; /* Remove gcc warning */ + bool eq(struct xid_t *xid) const + { return !xid->is_null() && eq(xid->gtrid_length, xid->bqual_length, xid->data); } + bool eq(long g, long b, const char *d) const + { return !is_null() && 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; + if ((gtrid_length= gl)) + memcpy(data, g, gl); + if ((bqual_length= bl)) + memcpy(data+gl, b, bl); + } + // Populate server_id if it's specified, otherwise use the current server_id + void set(ulonglong xid, decltype(::server_id) trx_server_id= server_id) + { + my_xid tmp; + formatID= 1; + set(MYSQL_XID_PREFIX_LEN, 0, MYSQL_XID_PREFIX); + memcpy(data+MYSQL_XID_PREFIX_LEN, &trx_server_id, sizeof(trx_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() const { 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; + } + decltype(::server_id) get_trx_server_id() + { + decltype(::server_id) trx_server_id; + memcpy(&trx_server_id, data+MYSQL_XID_PREFIX_LEN, sizeof(trx_server_id)); + return trx_server_id; + } + uint length() + { + return static_cast<uint>(sizeof(formatID)) + key_length(); + } + uchar *key() const + { + return (uchar *)>rid_length; + } + uint key_length() const + { + return static_cast<uint>(sizeof(gtrid_length)+sizeof(bqual_length)+ + gtrid_length+bqual_length); + } +}; +typedef struct xid_t XID; + +/* + Enumerates a sequence in the order of + their creation that is in the top-down order of the index file. + Ranges from zero through MAX_binlog_id. + Not confuse the value with the binlog file numerical suffix, + neither with the binlog file line in the binlog index file. +*/ +typedef uint Binlog_file_id; +const Binlog_file_id MAX_binlog_id= UINT_MAX; +const my_off_t MAX_off_t = (~(my_off_t) 0); +/* + Compound binlog-id and byte offset of transaction's first event + in a sequence (e.g the recovery sequence) of binlog files. + Binlog_offset(0,0) is the minimum value to mean + the first byte of the first binlog file. +*/ +typedef std::pair<Binlog_file_id, my_off_t> Binlog_offset; + +/* binlog-based recovery transaction descriptor */ +struct xid_recovery_member +{ + my_xid xid; + uint in_engine_prepare; // number of engines that have xid prepared + bool decided_to_commit; + /* + Semisync recovery binlog offset. It's initialized with the maximum + unreachable offset. The max value will remain for any transaction + not found in binlog to yield its rollback decision as it's guaranteed + to be within a truncated tail part of the binlog. + */ + Binlog_offset binlog_coord; + XID *full_xid; // needed by wsrep or past it recovery + decltype(::server_id) server_id; // server id of orginal server + + xid_recovery_member(my_xid xid_arg, uint prepare_arg, bool decided_arg, + XID *full_xid_arg, decltype(::server_id) server_id_arg) + : xid(xid_arg), in_engine_prepare(prepare_arg), + decided_to_commit(decided_arg), + binlog_coord(Binlog_offset(MAX_binlog_id, MAX_off_t)), + full_xid(full_xid_arg), server_id(server_id_arg) {}; +}; + +/* for recover() handlerton call */ +#define MIN_XID_LIST_SIZE 128 +#define MAX_XID_LIST_SIZE (1024*128) + +/* Statistics about batch operations like bulk_insert */ +struct ha_copy_info +{ + ha_rows records; /* Used to check if rest of variables can be used */ + ha_rows touched; + ha_rows copied; + ha_rows deleted; + ha_rows updated; +}; + +/* 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_CHECK_CONSTRAINTS, + SCH_COLLATIONS, + SCH_COLLATION_CHARACTER_SET_APPLICABILITY, + SCH_COLUMNS, + SCH_COLUMN_PRIVILEGES, + SCH_ENABLED_ROLES, + SCH_ENGINES, + SCH_EVENTS, + SCH_EXPLAIN_TABULAR, + SCH_EXPLAIN_JSON, + SCH_ANALYZE_TABULAR, + SCH_ANALYZE_JSON, + SCH_FILES, + SCH_GLOBAL_STATUS, + SCH_GLOBAL_VARIABLES, + SCH_KEYWORDS, + SCH_KEY_CACHES, + SCH_KEY_COLUMN_USAGE, + SCH_OPEN_TABLES, + SCH_OPT_TRACE, + SCH_PARAMETERS, + SCH_PARTITIONS, + SCH_PLUGINS, + SCH_PROCESSLIST, + SCH_PROFILES, + SCH_REFERENTIAL_CONSTRAINTS, + SCH_PROCEDURES, + SCH_SCHEMATA, + SCH_SCHEMA_PRIVILEGES, + SCH_SESSION_STATUS, + SCH_SESSION_VARIABLES, + SCH_STATISTICS, + SCH_SQL_FUNCTIONS, + SCH_SYSTEM_VARIABLES, + SCH_TABLES, + SCH_TABLESPACES, + SCH_TABLE_CONSTRAINTS, + SCH_TABLE_NAMES, + SCH_TABLE_PRIVILEGES, + SCH_TRIGGERS, + SCH_USER_PRIVILEGES, + SCH_VIEWS +}; + +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, size_t type_len, + const char *file, size_t file_len, + const char *status, size_t status_len); +enum ha_stat_type { HA_ENGINE_STATUS, HA_ENGINE_LOGS, HA_ENGINE_MUTEX }; +extern MYSQL_PLUGIN_IMPORT st_plugin_int *hton2plugin[MAX_HA]; + +struct handlerton; +#define view_pseudo_hton ((handlerton *)1) + +/* + 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; + +class handler; +class group_by_handler; +class derived_handler; +class select_handler; +struct Query; +typedef class st_select_lex SELECT_LEX; +typedef struct st_order ORDER; + +/* + handlerton is a singleton structure - one instance per storage engine - + to provide access to storage engine functionality that works on the + "global" level (unlike handler class that works on a per-table basis) + + usually handlerton instance is defined statically in ha_xxx.cc as + + static handlerton { ... } xxx_hton; + + savepoint_*, prepare, recover, and *_by_xid pointers can be 0. +*/ +struct handlerton +{ + /* + Historical number used for frm file to determine the correct + storage engine. This is going away and new engines will just use + "name" for this. + */ + enum legacy_db_type db_type; + /* + each storage engine has it's own memory area (actually a pointer) + in the thd, for storing per-connection information. + It is accessed as + + thd->ha_data[xxx_hton.slot] + + slot number is initialized by MySQL after xxx_init() is called. + */ + uint slot; + /* + to store per-savepoint data storage engine is provided with an area + of a requested size (0 is ok here). + savepoint_offset must be initialized statically to the size of + the needed memory to store per-savepoint information. + After xxx_init it is changed to be an offset to savepoint storage + area and need not be used by storage engine. + see binlog_hton and binlog_savepoint_set/rollback for an example. + */ + uint savepoint_offset; + /* + 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 asynchronously (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)(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); + /* + return 0 if dropped successfully, + -1 if nothing was done by design (as in e.g. blackhole) + an error code (e.g. HA_ERR_NO_SUCH_TABLE) otherwise + */ + int (*drop_table)(handlerton *hton, const 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)(); + alter_table_operations (*alter_table_flags)(alter_table_operations flags); + 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); + + void (*abort_transaction)(handlerton *hton, THD *bf_thd, THD *victim_thd, + my_bool signal) __attribute__((nonnull)); + int (*set_checkpoint)(handlerton *hton, const XID *xid); + int (*get_checkpoint)(handlerton *hton, XID* xid); + /** + Check if the version of the table matches the version in the .frm + file. + + This is mainly used to verify in recovery to check if an inplace + ALTER TABLE succeded. + Storage engines that does not support inplace alter table does not + have to implement this function. + + @param hton handlerton + @param path Path for table + @param version The unique id that is stored in the .frm file for + CREATE and updated for each ALTER TABLE (but not for + simple renames). + This is the ID used for the final table. + @param create_id The value returned from handler->table_version() for + the original table (before ALTER TABLE). + + @retval 0 If id matches or table is newer than create_id (depending + on what version check the engine supports. This means that + The (inplace) alter table did succeed. + @retval # > 0 Alter table did not succeed. + + Related to handler::discover_check_version(). + */ + int (*check_version)(handlerton *hton, const char *path, + const LEX_CUSTRING *version, ulonglong create_id); + + /* Called for all storage handlers after ddl recovery is done */ + void (*signal_ddl_recovery_done)(handlerton *hton); + + /* + 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 extensions (separate + metadata, index, and/or data files), the order of elements is relevant. + First element of engine file name extensions array should be metadata + file extention. This is implied by the open_table_error() + and the default discovery implementation. + + Second element - data file extension. This is implied + assumed by REPAIR TABLE ... USE_FRM implementation. + */ + const char **tablefile_extensions; // by default - empty list + + /********************************************************************** + Functions to intercept queries + **********************************************************************/ + + /* + Create and return a group_by_handler, if the storage engine can execute + the summary / group by query. + If the storage engine can't do that, return NULL. + + The server guaranteeds that all tables in the list belong to this + storage engine. + */ + group_by_handler *(*create_group_by)(THD *thd, Query *query); + + /* + Create and return a derived_handler if the storage engine can execute + the derived table 'derived', otherwise return NULL. + In a general case 'derived' may contain tables not from the engine. + If the engine cannot handle or does not want to handle such pushed derived + the function create_group_by has to return NULL. + */ + derived_handler *(*create_derived)(THD *thd, TABLE_LIST *derived); + + /* + Create and return a select_handler if the storage engine can execute + the select statement 'select, otherwise return NULL + */ + select_handler *(*create_select) (THD *thd, SELECT_LEX *select); + + /********************************************************************* + 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() = default; + }; + + /* + By default (if not implemented by the engine, but the discover_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_CSTRING *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); + + /* + Notify the storage engine that the definition of the table (and the .frm + file) has changed. Returns 0 if ok. + */ + int (*notify_tabledef_changed)(handlerton *hton, LEX_CSTRING *db, + LEX_CSTRING *table_name, LEX_CUSTRING *frm, + LEX_CUSTRING *org_tabledef_version, + handler *file); + + /* + System Versioning + */ + /** Determine if system-versioned data was modified by the transaction. + @param[in,out] thd current session + @param[out] trx_id transaction start ID + @return transaction commit ID + @retval 0 if no system-versioned data was affected by the transaction */ + ulonglong (*prepare_commit_versioned)(THD *thd, ulonglong *trx_id); + + /** Disable or enable the internal writes of a storage engine */ + void (*disable_internal_writes)(bool disable); + + /* backup */ + void (*prepare_for_backup)(void); + void (*end_backup)(void); + + /* Server shutdown early notification.*/ + void (*pre_shutdown)(void); + + /* + Inform handler that partitioning engine has changed the .frm and the .par + files + */ + int (*create_partitioning_metadata)(const char *path, + const char *old_path, + chf_create_flags action_flag); +}; + + +extern const char *hton_no_exts[]; + +static inline LEX_CSTRING *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 +#define HTON_NATIVE_SYS_VERSIONING (1 << 11) //Engine supports System Versioning + +// MySQL compatibility. Unused. +#define HTON_SUPPORTS_FOREIGN_KEYS (1 << 0) //Foreign key constraint supported. + +#define HTON_CAN_MERGE (1 <<11) //Merge type table +// Engine needs to access the main connect string in partitions +#define HTON_CAN_READ_CONNECT_STRING_IN_PARTITION (1 <<12) + +/* can be replicated by wsrep replication provider plugin */ +#define HTON_WSREP_REPLICATION (1 << 13) + +/* + Set this on the *slave* that's connected to a shared with a master storage. + The slave will ignore any CREATE TABLE, DROP or updates for this engine. +*/ +#define HTON_IGNORE_UPDATES (1 << 14) + +/* + Set this on the *master* that's connected to a shared with a slave storage. + The table may not exists on the slave. The effects of having this flag are: + - ALTER TABLE that changes engine from this table to another engine will + be replicated as CREATE + INSERT + - CREATE ... LIKE shared_table will be replicated as a full CREATE TABLE + - ALTER TABLE for this engine will have "IF EXISTS" added. + - RENAME TABLE for this engine will have "IF EXISTS" added. + - DROP TABLE for this engine will have "IF EXISTS" added. +*/ +#define HTON_TABLE_MAY_NOT_EXIST_ON_SLAVE (1 << 15) + +/* + True if handler cannot rollback transactions. If not true, the transaction + will be put in the transactional binlog cache. + For some engines, like Aria, the rollback can happen in case of crash, but + not trough a handler rollback call. +*/ +#define HTON_NO_ROLLBACK (1 << 16) + +/* + This storage engine can support both transactional and non transactional + tables +*/ +#define HTON_TRANSACTIONAL_AND_NON_TRANSACTIONAL (1 << 17) + +/* + Table requires and close and reopen after truncate + If the handler has HTON_CAN_RECREATE, this flag is not used +*/ +#define HTON_REQUIRES_CLOSE_AFTER_TRUNCATE (1 << 18) + +/* Truncate requires that all other handlers are closed */ +#define HTON_TRUNCATE_REQUIRES_EXCLUSIVE_USE (1 << 19) +/* + Used by mysql_inplace_alter_table() to decide if we should call + hton->notify_tabledef_changed() before commit (MyRocks) or after (InnoDB). +*/ +#define HTON_REQUIRES_NOTIFY_TABLEDEF_CHANGED_AFTER_COMMIT (1 << 20) + +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() = default; /* Remove gcc warning */ + + unsigned int m_unsafe_rollback_flags; + /* + Define the type of statements which cannot be rolled back safely. + Each type occupies one bit in m_unsafe_rollback_flags. + MODIFIED_NON_TRANS_TABLE is limited to mark only the temporary + non-transactional table *when* it's cached along with the transactional + events; the regular table is covered by the "namesake" bool var. + */ + enum unsafe_statement_types + { + MODIFIED_NON_TRANS_TABLE= 1, + CREATED_TEMP_TABLE= 2, + DROPPED_TEMP_TABLE= 4, + DID_WAIT= 8, + DID_DDL= 0x10, + EXECUTED_TABLE_ADMIN_CMD= 0x20 + }; + + void mark_modified_non_trans_temp_table() + { + m_unsafe_rollback_flags|= MODIFIED_NON_TRANS_TABLE; + } + bool has_modified_non_trans_temp_table() const + { + return (m_unsafe_rollback_flags & MODIFIED_NON_TRANS_TABLE) != 0; + } + void mark_executed_table_admin_cmd() + { + DBUG_PRINT("debug", ("mark_executed_table_admin_cmd")); + m_unsafe_rollback_flags|= EXECUTED_TABLE_ADMIN_CMD; + } + bool trans_executed_admin_cmd() + { + return (m_unsafe_rollback_flags & EXECUTED_TABLE_ADMIN_CMD) != 0; + } + void mark_created_temp_table() + { + DBUG_PRINT("debug", ("mark_created_temp_table")); + m_unsafe_rollback_flags|= CREATED_TEMP_TABLE; + } + void mark_dropped_temp_table() + { + DBUG_PRINT("debug", ("mark_dropped_temp_table")); + m_unsafe_rollback_flags|= DROPPED_TEMP_TABLE; + } + bool has_created_dropped_temp_table() const { + return + (m_unsafe_rollback_flags & (CREATED_TEMP_TABLE|DROPPED_TEMP_TABLE)) != 0; + } + void mark_trans_did_wait() { m_unsafe_rollback_flags|= DID_WAIT; } + bool trans_did_wait() const { + return (m_unsafe_rollback_flags & DID_WAIT) != 0; + } + bool is_trx_read_write() const; + void mark_trans_did_ddl() { m_unsafe_rollback_flags|= DID_DDL; } + bool trans_did_ddl() const { + return (m_unsafe_rollback_flags & DID_DDL) != 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; +}; + + +inline bool THD_TRANS::is_trx_read_write() const +{ + Ha_trx_info *ha_info; + for (ha_info= ha_list; ha_info; ha_info= ha_info->next()) + if (ha_info->is_trx_read_write()) + return TRUE; + return FALSE; +} + + +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 max_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; + bool check_sum_null; +} 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 of the schema default character set, collation + and schema_comment. +*/ +struct Schema_specification_st +{ + CHARSET_INFO *default_table_charset; + LEX_CSTRING *schema_comment; + void init() + { + bzero(this, sizeof(*this)); + } +}; + +class Create_field; + +struct Table_period_info: Sql_alloc +{ + Table_period_info() : + create_if_not_exists(false), + constr(NULL), + unique_keys(0) {} + Table_period_info(const char *name_arg, size_t size) : + name(name_arg, size), + create_if_not_exists(false), + constr(NULL), + unique_keys(0){} + + Lex_ident name; + + struct start_end_t + { + start_end_t() = default; + start_end_t(const LEX_CSTRING& _start, const LEX_CSTRING& _end) : + start(_start), + end(_end) {} + Lex_ident start; + Lex_ident end; + }; + start_end_t period; + bool create_if_not_exists; + Virtual_column_info *constr; + uint unique_keys; + + bool is_set() const + { + DBUG_ASSERT(bool(period.start) == bool(period.end)); + return period.start; + } + + void set_period(const Lex_ident& start, const Lex_ident& end) + { + period.start= start; + period.end= end; + } + bool check_field(const Create_field* f, const Lex_ident& f_name) const; +}; + +struct Vers_parse_info: public Table_period_info +{ + Vers_parse_info() : + Table_period_info(STRING_WITH_LEN("SYSTEM_TIME")), + versioned_fields(false), + unversioned_fields(false), + can_native(-1) + {} + + Table_period_info::start_end_t as_row; + + friend struct Table_scope_and_contents_source_st; + void set_start(const LEX_CSTRING field_name) + { + as_row.start= field_name; + period.start= field_name; + } + void set_end(const LEX_CSTRING field_name) + { + as_row.end= field_name; + period.end= field_name; + } + +protected: + bool is_start(const char *name) const; + bool is_end(const char *name) const; + bool is_start(const Create_field &f) const; + bool is_end(const Create_field &f) const; + bool fix_implicit(THD *thd, Alter_info *alter_info); + operator bool() const + { + return as_row.start || as_row.end || period.start || period.end; + } + bool need_check(const Alter_info *alter_info) const; + bool check_conditions(const Lex_table_name &table_name, + const Lex_table_name &db) const; + bool create_sys_field(THD *thd, const char *field_name, + Alter_info *alter_info, int flags); + +public: + static const Lex_ident default_start; + static const Lex_ident default_end; + + bool fix_alter_info(THD *thd, Alter_info *alter_info, + HA_CREATE_INFO *create_info, TABLE *table); + bool fix_create_like(Alter_info &alter_info, HA_CREATE_INFO &create_info, + TABLE_LIST &src_table, TABLE_LIST &table); + bool check_sys_fields(const Lex_table_name &table_name, + const Lex_table_name &db, Alter_info *alter_info) const; + + /** + At least one field was specified 'WITH/WITHOUT SYSTEM VERSIONING'. + Useful for error handling. + */ + bool versioned_fields : 1; + bool unversioned_fields : 1; + int can_native; +}; + +/** + 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_pod_st // For trivial members +{ + CHARSET_INFO *alter_table_convert_to_charset; + LEX_CUSTRING tabledef_version; + LEX_CUSTRING org_tabledef_version; /* version of dropped table */ + LEX_CSTRING connect_string; + LEX_CSTRING comment; + LEX_CSTRING alias; + LEX_CSTRING org_storage_engine_name, new_storage_engine_name; + const char *password, *tablespace; + const char *data_file_name, *index_file_name; + 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; + ulong expression_length; + ulong field_check_constraints; + /* + 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 */ + 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 + bool sequence; // If SEQUENCE=1 was used + + List<Virtual_column_info> *check_constraint_list; + + /* 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; + TABLE_LIST *merge_list; + MDL_ticket *mdl_ticket; + bool table_was_deleted; + sequence_definition *seq_create_info; + + 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); + } + + bool versioned() const + { + return options & HA_VERSIONED_TABLE; + } +}; + + +struct Table_scope_and_contents_source_st: + public Table_scope_and_contents_source_pod_st +{ + Vers_parse_info vers_info; + Table_period_info period_info; + + void init() + { + Table_scope_and_contents_source_pod_st::init(); + vers_info= {}; + period_info= {}; + } + + bool fix_create_fields(THD *thd, Alter_info *alter_info, + const TABLE_LIST &create_table); + bool fix_period_fields(THD *thd, Alter_info *alter_info); + bool check_fields(THD *thd, Alter_info *alter_info, + const Lex_table_name &table_name, + const Lex_table_name &db, + int select_count= 0); + bool check_period_fields(THD *thd, Alter_info *alter_info); + + void vers_check_native(); + bool vers_fix_system_fields(THD *thd, Alter_info *alter_info, + const TABLE_LIST &create_table); + + bool vers_check_system_fields(THD *thd, Alter_info *alter_info, + const Lex_table_name &table_name, + const Lex_table_name &db, + int select_count= 0); +}; + + +/** + 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 +{ + /* TODO: remove after MDEV-20865 */ + Alter_info *alter_info; + + void init() + { + Table_scope_and_contents_source_st::init(); + Schema_specification_st::init(); + alter_info= NULL; + } + ulong table_options_with_row_type() + { + if (row_type == ROW_TYPE_DYNAMIC || row_type == ROW_TYPE_PAGE) + return table_options | HA_OPTION_PACK_RECORD; + else + return table_options; + } + bool resolve_to_charset_collation_context(THD *thd, + const Lex_table_charset_collation_attrs_st &default_cscl, + const Lex_table_charset_collation_attrs_st &convert_cscl, + const Charset_collation_context &ctx); +}; + + +/** + 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 +{ + Lex_table_charset_collation_attrs_st default_charset_collation; + Lex_table_charset_collation_attrs_st convert_charset_collation; + + // Deep initialization + void init() + { + HA_CREATE_INFO::init(); + DDL_options_st::init(); + default_charset_collation.init(); + convert_charset_collation.init(); + } + void init(DDL_options_st::Options options_arg) + { + HA_CREATE_INFO::init(); + DDL_options_st::init(options_arg); + default_charset_collation.init(); + convert_charset_collation.init(); + } + /* + 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(); + default_charset_collation.init(); + convert_charset_collation.init(); + } + + bool add_table_option_convert_charset(CHARSET_INFO *cs) + { + // cs can be NULL, e.g.: ALTER TABLE t1 CONVERT TO CHARACTER SET DEFAULT; + used_fields|= (HA_CREATE_USED_CHARSET | HA_CREATE_USED_DEFAULT_CHARSET); + return cs ? + convert_charset_collation.merge_exact_charset(Lex_exact_charset(cs)) : + convert_charset_collation.merge_charset_default(); + } + bool add_table_option_convert_collation(const Lex_extended_collation_st &cl) + { + used_fields|= (HA_CREATE_USED_CHARSET | HA_CREATE_USED_DEFAULT_CHARSET); + return convert_charset_collation.merge_collation(cl); + } + + bool add_table_option_default_charset(CHARSET_INFO *cs) + { + // cs can be NULL, e.g.: CREATE TABLE t1 (..) CHARACTER SET DEFAULT; + used_fields|= HA_CREATE_USED_DEFAULT_CHARSET; + return cs ? + default_charset_collation.merge_exact_charset(Lex_exact_charset(cs)) : + default_charset_collation.merge_charset_default(); + } + bool add_table_option_default_collation(const Lex_extended_collation_st &cl) + { + used_fields|= HA_CREATE_USED_DEFAULT_CHARSET; + return default_charset_collation.merge_collation(cl); + } + + bool resolve_to_charset_collation_context(THD *thd, + const Charset_collation_context &ctx) + { + return HA_CREATE_INFO:: + resolve_to_charset_collation_context(thd, + default_charset_collation, + convert_charset_collation, + ctx); + } +}; + + +/** + Structure describing changes to an index to be caused by ALTER TABLE. +*/ + +struct KEY_PAIR +{ + /** + Pointer to KEY object describing old version of index in + TABLE::key_info array for TABLE instance representing old + version of table. + */ + KEY *old_key; + /** + Pointer to KEY object describing new version of index in + Alter_inplace_info::key_info_buffer array. + */ + KEY *new_key; +}; + + +/** + 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() = default; + + virtual ~inplace_alter_handler_ctx() = default; + virtual void set_shared_data(const inplace_alter_handler_ctx& 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: + + /** + 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= 0; + + /** + Array of pointers to KEYs to be dropped belonging to the TABLE instance + for the old version of the table. + */ + KEY **index_drop_buffer= nullptr; + + /** Size of index_add_buffer array. */ + uint index_add_count= 0; + + /** + Array of indexes into key_info_buffer for KEYs to be added, + sorted in increasing order. + */ + uint *index_add_buffer= nullptr; + + KEY_PAIR *index_altered_ignorability_buffer= nullptr; + + /** Size of index_altered_ignorability_buffer array. */ + uint index_altered_ignorability_count= 0; + + /** + Old and new index names. Used for index rename. + */ + struct Rename_key_pair + { + Rename_key_pair(const KEY *old_key, const KEY *new_key) + : old_key(old_key), new_key(new_key) + { + } + const KEY *old_key; + const KEY *new_key; + }; + /** + Vector of key pairs from DROP/ADD index which can be renamed. + */ + typedef Mem_root_array<Rename_key_pair, true> Rename_keys_vector; + + /** + A list of indexes which should be renamed. + Index definitions stays the same. + */ + Rename_keys_vector rename_keys; + + /** + 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= nullptr; + + /** + 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= nullptr; + + /** + Flags describing in detail which operations the storage engine is to + execute. Flags are defined in sql_alter.h + */ + alter_table_operations handler_flags= 0; + + /* Alter operations involving parititons are strored here */ + ulong partition_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 * const modified_part_info; + + /** true for ALTER IGNORE TABLE ... */ + const bool ignore; + + /** true for online operation (LOCK=NONE) */ + bool online= false; + + /** + When ha_commit_inplace_alter_table() is called the the engine can + set this to a function to be called after the ddl log + is committed. + */ + typedef void (inplace_alter_table_commit_callback)(void *); + inplace_alter_table_commit_callback *inplace_alter_table_committed= nullptr; + + /* This will be used as the argument to the above function when called */ + void *inplace_alter_table_committed_argument= nullptr; + + /** which ALGORITHM and LOCK are supported by the storage engine */ + enum_alter_inplace_result inplace_supported; + + /** + 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_COPY_NO_LOCK) + 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= nullptr; + + /** true when InnoDB should abort the alter when table is not empty */ + const bool error_if_not_empty; + + /** True when DDL should avoid downgrading the MDL */ + bool mdl_exclusive_after_prepare= false; + + 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, bool error_non_empty); + + ~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) const; + void add_altered_index_ignorability(KEY *old_key, KEY *new_key) + { + KEY_PAIR *key_pair= index_altered_ignorability_buffer + + index_altered_ignorability_count++; + key_pair->old_key= old_key; + key_pair->new_key= new_key; + DBUG_PRINT("info", ("index had ignorability altered: %i to %i", + old_key->is_ignored, + new_key->is_ignored)); + } + + +}; + + +typedef struct st_key_create_information +{ + enum ha_key_alg algorithm; + ulong block_size; + uint flags; /* HA_USE.. flags */ + LEX_CSTRING parser_name; + LEX_CSTRING comment; + bool is_ignored; +} KEY_CREATE_INFO; + + +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() = default; /* 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 to fetch records */ + double avg_io_cost; /* cost of an average I/O oper. to fetch records */ + double idx_io_count; /* number of I/O to read keys */ + double idx_avg_io_cost; /* cost of an average I/O oper. to fetch records */ + double cpu_cost; /* total cost of operations in CPU */ + double idx_cpu_cost; /* cost of operations in CPU for index */ + double import_cost; /* cost of remote operations */ + double mem_cost; /* cost of used memory */ + + static constexpr double IO_COEFF= 1; + static constexpr double CPU_COEFF= 1; + static constexpr double MEM_COEFF= 1; + static constexpr double IMPORT_COEFF= 1; + + Cost_estimate() + { + reset(); + } + + double total_cost() const + { + return IO_COEFF*io_count*avg_io_cost + + IO_COEFF*idx_io_count*idx_avg_io_cost + + CPU_COEFF*(cpu_cost + idx_cpu_cost) + + MEM_COEFF*mem_cost + IMPORT_COEFF*import_cost; + } + + double index_only_cost() + { + return IO_COEFF*idx_io_count*idx_avg_io_cost + + CPU_COEFF*idx_cpu_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 == 0.0 && idx_io_count == 0.0 && cpu_cost == 0.0 && + import_cost == 0.0 && mem_cost == 0.0; + } + + void reset() + { + avg_io_cost= 1.0; + idx_avg_io_cost= 1.0; + io_count= idx_io_count= cpu_cost= idx_cpu_cost= mem_cost= import_cost= 0.0; + } + + void multiply(double m) + { + io_count *= m; + cpu_cost *= m; + idx_io_count *= m; + idx_cpu_cost *= m; + import_cost *= m; + /* Don't multiply mem_cost */ + } + + void add(const Cost_estimate* cost) + { + if (cost->io_count != 0.0) + { + double io_count_sum= io_count + cost->io_count; + avg_io_cost= (io_count * avg_io_cost + + cost->io_count * cost->avg_io_cost) + /io_count_sum; + io_count= io_count_sum; + } + if (cost->idx_io_count != 0.0) + { + double idx_io_count_sum= idx_io_count + cost->idx_io_count; + idx_avg_io_cost= (idx_io_count * idx_avg_io_cost + + cost->idx_io_count * cost->idx_avg_io_cost) + /idx_io_count_sum; + idx_io_count= idx_io_count_sum; + } + cpu_cost += cost->cpu_cost; + idx_cpu_cost += cost->idx_cpu_cost; + import_cost += cost->import_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 1U +#define HA_MRR_FIXED_KEY 2U + +/* + Indicates that RANGE_SEQ_IF::next(&range) doesn't need to fill in the + 'range' parameter. +*/ +#define HA_MRR_NO_ASSOCIATION 4U + +/* + The MRR user will provide ranges in key order, and MRR implementation + must return rows in key order. +*/ +#define HA_MRR_SORTED 8U + +/* MRR implementation doesn't have to retrieve full records */ +#define HA_MRR_INDEX_ONLY 16U + +/* + The passed memory buffer is of maximum possible size, the caller can't + assume larger buffer. +*/ +#define HA_MRR_LIMITS 32U + + +/* + 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 64U + +/* + 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 128U + +/* + 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 256U + +/* + 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 512U +#define HA_MRR_IMPLEMENTATION_FLAG2 1024U +#define HA_MRR_IMPLEMENTATION_FLAG3 2048U +#define HA_MRR_IMPLEMENTATION_FLAG4 4096U +#define HA_MRR_IMPLEMENTATION_FLAG5 8192U +#define HA_MRR_IMPLEMENTATION_FLAG6 16384U + +#define HA_MRR_IMPLEMENTATION_FLAGS \ + (512U | 1024U | 2048U | 4096U | 8192U | 16384U) + +/* + 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 */ + ha_checksum checksum; + bool checksum_null; + + /* + 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), max_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(8192), + checksum(0), checksum_null(FALSE), mrr_length_per_rec(0) + {} +}; + +extern "C" check_result_t handler_index_cond_check(void* h_arg); + +extern "C" check_result_t handler_rowid_filter_check(void* h_arg); +extern "C" int handler_rowid_filter_is_active(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() = default; + virtual ~Handler_share() = default; +}; + +enum class Compare_keys : uint32_t +{ + Equal= 0, + EqualButKeyPartLength, + EqualButComment, + NotEqual +}; + +/** + 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; + handler *lookup_handler; + /* Statistics for the query. Updated if handler_stats.in_use is set */ + ha_handler_stats active_handler_stats; + void set_handler_stats(); +public: + handlerton *ht; /* storage engine of this handler */ + uchar *ref; /* Pointer to current row */ + uchar *dup_ref; /* Pointer to duplicate row */ + uchar *lookup_buffer; + + /* General statistics for the table like number of row, file sizes etc */ + ha_statistics stats; + /* + Collect query stats here if pointer is != NULL. + This is a pointer because if we do a clone of the handler, we want to + use the original handler for collecting statistics. + */ + ha_handler_stats *handler_stats; + + /** MultiRangeRead-related members: */ + range_seq_t mrr_iter; /* Iterator 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 */ + /** 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; + + /* 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; + bool eq_range; + bool internal_tmp_table; /* If internal tmp table */ + bool implicit_emptied; /* Can be !=0 only if HEAP */ + bool mark_trx_read_write_done; /* mark_trx_read_write was called */ + bool check_table_binlog_row_based_done; /* check_table_binlog.. was called */ + bool check_table_binlog_row_based_result; /* cached check_table_binlog... */ + /* + TRUE <=> the engine guarantees that returned records are within the range + being scanned. + */ + bool in_range_check_pushed_down; + + uint lookup_errkey; + uint errkey; /* Last dup key */ + uint key_used_on_scan; + uint active_index, keyread; + + /** Length of ref (1-8 or the clustered key length) */ + uint ref_length; + FT_INFO *ft_handler; + enum init_stat { NONE=0, INDEX, RND }; + init_stat inited, pre_inited; + + 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]; + ha_copy_info copy_info; + +private: + /* ANALYZE time tracker, if present */ + Exec_time_tracker *tracker; +public: + void set_time_tracker(Exec_time_tracker *tracker_arg) { tracker=tracker_arg;} + Exec_time_tracker *get_time_tracker() { return tracker; } + + Item *pushed_idx_cond; + uint pushed_idx_cond_keyno; /* The index which the above condition is for */ + + /* Rowid filter pushed into the engine */ + Rowid_filter *pushed_rowid_filter; + /* true when the pushed rowid filter has been already filled */ + bool rowid_filter_is_active; + /* Used for disabling/enabling pushed_rowid_filter */ + Rowid_filter *save_pushed_rowid_filter; + bool save_rowid_filter_is_active; + + 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; + +private: + /** Internal state of the batch instrumentation. */ + enum batch_mode_t + { + /** Batch mode not used. */ + PSI_BATCH_MODE_NONE, + /** Batch mode used, before first table io. */ + PSI_BATCH_MODE_STARTING, + /** Batch mode used, after first table io. */ + PSI_BATCH_MODE_STARTED + }; + /** + Batch mode state. + @sa start_psi_batch_mode. + @sa end_psi_batch_mode. + */ + batch_mode_t m_psi_batch_mode; + /** + The number of rows in the batch. + @sa start_psi_batch_mode. + @sa end_psi_batch_mode. + */ + ulonglong m_psi_numrows; + /** + The current event in a batch. + @sa start_psi_batch_mode. + @sa end_psi_batch_mode. + */ + PSI_table_locker *m_psi_locker; + /** + Storage for the event in a batch. + @sa start_psi_batch_mode. + @sa end_psi_batch_mode. + */ + PSI_table_locker_state m_psi_locker_state; + +public: + virtual void unbind_psi(); + virtual void rebind_psi(); + /* Return error if definition doesn't match for already opened table */ + virtual int discover_check_version() { return 0; } + + /** + Put the handler in 'batch' mode when collecting + table io instrumented events. + When operating in batch mode: + - a single start event is generated in the performance schema. + - all table io performed between @c start_psi_batch_mode + and @c end_psi_batch_mode is not instrumented: + the number of rows affected is counted instead in @c m_psi_numrows. + - a single end event is generated in the performance schema + when the batch mode ends with @c end_psi_batch_mode. + */ + void start_psi_batch_mode(); + /** End a batch started with @c start_psi_batch_mode. */ + void end_psi_batch_mode(); + + /* If we have row logging enabled for this table */ + bool row_logging, row_logging_init; + /* If the row logging should be done in transaction cache */ + bool row_logging_has_trans; + +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), + lookup_handler(this), + ht(ht_arg), ref(0), lookup_buffer(NULL), handler_stats(NULL), + end_range(NULL), implicit_emptied(0), + mark_trx_read_write_done(0), + check_table_binlog_row_based_done(0), + check_table_binlog_row_based_result(0), + in_range_check_pushed_down(FALSE), lookup_errkey(-1), errkey(-1), + key_used_on_scan(MAX_KEY), + active_index(MAX_KEY), keyread(MAX_KEY), + ref_length(sizeof(my_off_t)), + ft_handler(0), inited(NONE), pre_inited(NONE), + 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), + pushed_rowid_filter(NULL), + rowid_filter_is_active(0), + save_pushed_rowid_filter(NULL), + save_rowid_filter_is_active(false), + auto_inc_intervals_count(0), + m_psi(NULL), + m_psi_batch_mode(PSI_BATCH_MODE_NONE), + m_psi_numrows(0), + m_psi_locker(NULL), + row_logging(0), row_logging_init(0), + 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); + } + /* To check if table has been properely opened */ + bool is_open() + { + return ref != 0; + } + 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: public wrappers for private virtual API */ + + int ha_open(TABLE *table, const char *name, int mode, uint test_if_locked, + MEM_ROOT *mem_root= 0, List<String> *partitions_to_open=NULL); + 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 + { + DBUG_ASSERT(cached_table_flags < (HA_LAST_TABLE_FLAG << 1)); + 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_external_unlock(THD *thd) { return ha_external_lock(thd, F_UNLCK); } + int ha_write_row(const uchar * buf); + int ha_update_row(const uchar * old_data, const uchar * new_data); + int ha_delete_row(const uchar * buf); + void ha_release_auto_increment(); + + bool keyread_enabled() { return keyread < MAX_KEY; } + int ha_start_keyread(uint idx) + { + int res= keyread_enabled() ? 0 : extra_opt(HA_EXTRA_KEYREAD, idx); + keyread= idx; + return res; + } + int ha_end_keyread() + { + if (!keyread_enabled()) + return 0; + keyread= MAX_KEY; + return extra(HA_EXTRA_NO_KEYREAD); + } + + int check_collation_compatibility(); + int check_long_hash_compatibility() const; + 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; + bzero(©_info,sizeof(copy_info)); + start_bulk_insert(rows, flags); + DBUG_VOID_RETURN; + } + int ha_end_bulk_insert(); + int ha_bulk_update_row(const uchar *old_data, const uchar *new_data, + ha_rows *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); + 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, + chf_create_flags 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)); + bzero(©_info, sizeof(copy_info)); + } + virtual void reset_copy_info() {} + void ha_reset_copy_info() + { + bzero(©_info, sizeof(copy_info)); + reset_copy_info(); + } + 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) / stats.block_size + 2) * + avg_io_cost()); + } + + virtual double key_scan_time(uint index) + { + return keyread_time(index, 1, records()); + } + + virtual double avg_io_cost() + { + return 1.0; + } + + /** + 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. If 0, it means that + we calculate separately the cost of reading the key. + @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; } + + /* + True if changes to the table is persistent (if there are no rollback) + This is used to decide: + - If the table is stored in the transaction or non transactional binary + log + - How things are tracked in trx and in add_changed_table(). + - If we can combine several statements under one commit in the binary log. + */ + bool has_transactions() const + { + return ((ha_table_flags() & (HA_NO_TRANSACTIONS | HA_PERSISTENT_TABLE)) + == 0); + } + /* + True if table has both transactions and rollback. This is used to decide + if we should write the changes to the binary log. If this is true, + we don't have to write failed statements to the log as they can be + rolled back. + */ + bool has_transactions_and_rollback() const + { + return has_transactions() && has_rollback(); + } + /* + True if the underlaying table support transactions and rollback + */ + bool has_transaction_manager() const + { + return ((ha_table_flags() & HA_NO_TRANSACTIONS) == 0 && has_rollback()); + } + + /* + True if the underlaying table support TRANSACTIONAL table option + */ + bool has_transactional_option() const + { + extern handlerton *maria_hton; + return partition_ht() == maria_hton || has_transaction_manager(); + } + + /* + True if table has rollback. Used to check if an update on the table + can be killed fast. + */ + + bool has_rollback() const + { + return ((ht->flags & HTON_NO_ROLLBACK) == 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 || + ((flags & HA_CHECK_FK_ERROR) && + (error == HA_ERR_ROW_IS_REFERENCED || + error == HA_ERR_NO_REFERENCED_ROW))) + 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 int pre_records() { return 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(ha_rows *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 int end_bulk_update() { return 0; } + /** + 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; + } + virtual int pre_index_read_map(const uchar *key, + key_part_map keypart_map, + enum ha_rkey_function find_flag, + bool use_parallel) + { return 0; } + virtual int pre_index_first(bool use_parallel) + { return 0; } + virtual int pre_index_last(bool use_parallel) + { return 0; } + virtual int pre_index_read_last_map(const uchar *key, + key_part_map keypart_map, + bool use_parallel) + { return 0; } +/* + virtual int pre_read_multi_range_first(KEY_MULTI_RANGE **found_range_p, + KEY_MULTI_RANGE *ranges, + uint range_count, + bool sorted, HANDLER_BUFFER *buffer, + bool use_parallel); +*/ + virtual int pre_multi_range_read_next(bool use_parallel) + { return 0; } + virtual int pre_read_range_first(const key_range *start_key, + const key_range *end_key, + bool eq_range, bool sorted, + bool use_parallel) + { return 0; } + virtual int pre_ft_read(bool use_parallel) + { return 0; } + virtual int pre_rnd_next(bool use_parallel) + { return 0; } + int ha_pre_rnd_init(bool scan) + { + int result; + DBUG_ENTER("ha_pre_rnd_init"); + DBUG_ASSERT(pre_inited==NONE || (pre_inited==RND && scan)); + pre_inited= (result= pre_rnd_init(scan)) ? NONE: RND; + DBUG_RETURN(result); + } + int ha_pre_rnd_end() + { + DBUG_ENTER("ha_pre_rnd_end"); + DBUG_ASSERT(pre_inited==RND); + pre_inited=NONE; + DBUG_RETURN(pre_rnd_end()); + } + virtual int pre_rnd_init(bool scan) { return 0; } + virtual int pre_rnd_end() { return 0; } + virtual int pre_index_init(uint idx, bool sorted) { return 0; } + virtual int pre_index_end() { return 0; } + int ha_pre_index_init(uint idx, bool sorted) + { + int result; + DBUG_ENTER("ha_pre_index_init"); + DBUG_ASSERT(pre_inited==NONE); + if (!(result= pre_index_init(idx, sorted))) + pre_inited=INDEX; + DBUG_RETURN(result); + } + int ha_pre_index_end() + { + DBUG_ENTER("ha_pre_index_end"); + DBUG_ASSERT(pre_inited==INDEX); + pre_inited=NONE; + DBUG_RETURN(pre_index_end()); + } + int ha_pre_index_or_rnd_end() + { + return (pre_inited == INDEX ? + ha_pre_index_end() : + pre_inited == RND ? ha_pre_rnd_end() : 0 ); + } + virtual bool vers_can_native(THD *thd) + { + return ht->flags & HTON_NATIVE_SYS_VERSIONING; + } + + /** + @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); + /** + @brief + The following functions works like index_read, but it find the last + row with the current key value or prefix. + @returns @see index_read_map(). + */ + virtual int index_read_last_map(uchar * buf, const uchar * key, + key_part_map keypart_map) + { + uint key_len= calculate_key_len(table, active_index, key, keypart_map); + return index_read_last(buf, key, key_len); + } + 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) const; + virtual int ft_init() { return HA_ERR_WRONG_COMMAND; } + virtual int pre_ft_init() { return HA_ERR_WRONG_COMMAND; } + virtual void ft_end() {} + virtual int pre_ft_end() { return 0; } + virtual FT_INFO *ft_init_ext(uint flags, uint inx,String *key) + { return NULL; } +public: + 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) + { + int error; + DBUG_ASSERT(table_flags() & HA_PRIMARY_KEY_REQUIRED_FOR_POSITION); + + error = ha_rnd_init(false); + if (error != 0) + return error; + + position(record); + error = ha_rnd_pos(record, ref); + ha_rnd_end(); + return error; + } + virtual int read_first_row(uchar *buf, uint primary_key); +public: + + /* Same as above, but with statistics */ + inline int ha_ft_read(uchar *buf); + inline void ha_ft_end() { ft_end(); ft_handler=NULL; } + 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 2 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 ha_rows records_in_range(uint inx, const key_range *min_key, + const key_range *max_key, + page_range *res) + { 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 void set_partitions_to_open(List<String> *partition_names) {} + virtual bool check_if_updates_are_ignored(const char *op) const; + virtual int change_partitions_to_open(List<String> *partition_names) + { return 0; } + virtual int extra(enum ha_extra_function operation) + { return 0; } + virtual int extra_opt(enum ha_extra_function operation, ulong arg) + { return extra(operation); } + /* + Table version id for the the table. This should change for each + sucessfull ALTER TABLE. + This is used by the handlerton->check_version() to ask the engine + if the table definition has been updated. + Storage engines that does not support inplace alter table does not + have to support this call. + */ + virtual ulonglong table_version() const { return 0; } + + /** + 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. + */ + bool ha_was_semi_consistent_read(); + 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 bool need_info_for_auto_inc() { return 0; } + virtual bool can_use_for_auto_inc_init() { return 1; } + 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; + } + virtual 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 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 */ + virtual const char *table_type() const { return hton_name(ht)->str; } + /* The following is same as table_table(), except for partition engine */ + virtual const char *real_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 void return_record_by_parent() { return; } + + /* Information about index. Both index and part starts from 0 */ + 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_DATA_LENGTH_FOR_KEY, max_supported_key_length()); } + uint max_key_part_length() const + { return MY_MIN(MAX_DATA_LENGTH_FOR_KEY, 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_DATA_LENGTH_FOR_KEY; } + virtual uint max_supported_key_part_length() const { return 255; } + virtual uint min_record_length(uint options) const { return 1; } + + virtual int pre_calculate_checksum() { return 0; } + virtual int calculate_checksum(); + 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(); + + /** + @note lock_count() can return > 1 if the table is MERGE or partitioned. + */ + virtual uint lock_count(void) const { return 1; } + /** + Get the lock(s) for the table and perform conversion of locks if needed. + + 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 cacheable. 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, const char *table_key, + uint key_length, + qc_engine_callback *callback, + ulonglong *engine_data) + { + *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 key is a clustering key + + - 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. + + Note that in many cases a clustered key is also a reference key. + This means that: + + - The 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 key + key value as a position(). InnoDB is an example of such an engine. + + For 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 + + For a reference key the following should also hold: + table_flags() should contain HA_PRIMARY_KEY_IS_READ_INDEX. + + @retval TRUE yes + @retval FALSE No. + */ + + /* The following code is for primary keys */ + bool pk_is_clustering_key(uint index) const + { + /* + We have to check for MAX_INDEX as table->s->primary_key can be + MAX_KEY in the case where there is no primary key. + */ + return index != MAX_KEY && is_clustering_key(index); + } + /* Same as before but for other keys, in which case we can skip the check */ + bool is_clustering_key(uint index) const + { + DBUG_ASSERT(index != MAX_KEY); + return (index_flags(index, 0, 1) & HA_CLUSTERED_INDEX); + } + + 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 metadata for the current operation down to the table handler. + */ + virtual int info_push(uint info_type, void *info) { return 0; }; + + /** + 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; + } + + virtual void cancel_pushed_rowid_filter() + { + pushed_rowid_filter= NULL; + rowid_filter_is_active= false; + } + + virtual void disable_pushed_rowid_filter() + { + DBUG_ASSERT(pushed_rowid_filter != NULL && + save_pushed_rowid_filter == NULL); + save_pushed_rowid_filter= pushed_rowid_filter; + if (rowid_filter_is_active) + save_rowid_filter_is_active= rowid_filter_is_active; + pushed_rowid_filter= NULL; + rowid_filter_is_active= false; + } + + virtual void enable_pushed_rowid_filter() + { + DBUG_ASSERT(save_pushed_rowid_filter != NULL && + pushed_rowid_filter == NULL); + pushed_rowid_filter= save_pushed_rowid_filter; + if (save_rowid_filter_is_active) + rowid_filter_is_active= true; + save_pushed_rowid_filter= NULL; + } + + virtual bool rowid_filter_push(Rowid_filter *rowid_filter) { return true; } + + /* Needed for partition / spider */ + virtual TABLE_LIST *get_next_global_for_child() { return NULL; } + + /** + 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_COPY_LOCK + or HA_ALTER_INPLACE_COPY_NO_LOCK 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 occurred 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 + hton::notify_table_changed() + *) 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_COPY_LOCK + 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_COPY_NO_LOCK + 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); + + +protected: + /** + Allows the storage engine to update internal structures with concurrent + writes blocked. If check_if_supported_inplace_alter() returns + HA_ALTER_INPLACE_COPY_NO_LOCK or HA_ALTER_INPLACE_COPY_LOCK, + 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; +} + +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 alter_table_operations alter_table_flags(alter_table_operations flags) + { + if (ht->alter_table_flags) + return ht->alter_table_flags(flags); + return 0; + } + + virtual LEX_CSTRING *engine_name(); + + TABLE* get_table() { return table; } + TABLE_SHARE* get_table_share() { return table_share; } +protected: + /* Service methods for use by storage engines. */ + 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); + + +public: + /** + Delete a table in the engine. Called for base as well as temporary + tables. + */ + virtual int delete_table(const char *name); + bool check_table_binlog_row_based(); + bool prepare_for_row_logging(); + int prepare_for_insert(bool do_create); + int binlog_log_row(TABLE *table, + const uchar *before_record, + const uchar *after_record, + Log_func *log_func); + + inline void clear_cached_table_binlog_row_based_flag() + { + check_table_binlog_row_based_done= 0; + } + virtual void handler_stats_updated() {} + + inline void ha_handler_stats_reset() + { + handler_stats= &active_handler_stats; + active_handler_stats.reset(); + active_handler_stats.active= 1; + handler_stats_updated(); + } + inline void ha_handler_stats_disable() + { + handler_stats= 0; + active_handler_stats.active= 0; + handler_stats_updated(); + } + +private: + /* Cache result to avoid extra calls */ + inline void mark_trx_read_write() + { + if (unlikely(!mark_trx_read_write_done)) + { + mark_trx_read_write_done= 1; + mark_trx_read_write_internal(); + } + } + +private: + void mark_trx_read_write_internal(); + bool check_table_binlog_row_based_internal(); + + int create_lookup_handler(); + void alloc_lookup_buffer(); + int check_duplicate_long_entries(const uchar *new_rec); + int check_duplicate_long_entries_update(const uchar *new_rec); + int check_duplicate_long_entry_key(const uchar *new_rec, uint key_no); + /** PRIMARY KEY/UNIQUE WITHOUT OVERLAPS check */ + int ha_check_overlaps(const uchar *old_data, const uchar* new_data); + +protected: + /* + These are intended to be used only by handler::ha_xxxx() functions + However, engines that implement read_range_XXX() (like MariaRocks) + or embed other engines (like ha_partition) may need to call these also + */ + inline void increment_statistics(ulong SSV::*offset) const; + inline void decrement_statistics(ulong SSV::*offset) const; + +private: + /* + 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(const 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)), + const uchar *new_data __attribute__((unused))) + { + return HA_ERR_WRONG_COMMAND; + } + + /* + Optimized function for updating the first row. Only used by sequence + tables + */ + virtual int update_first_row(const uchar *new_data); + + virtual int delete_row(const uchar *buf __attribute__((unused))) + { + return HA_ERR_WRONG_COMMAND; + } + + /* Perform initialization for a direct update request */ +public: + int ha_direct_update_rows(ha_rows *update_rows, ha_rows *found_rows); + virtual int direct_update_rows_init(List<Item> *update_fields) + { + return HA_ERR_WRONG_COMMAND; + } +private: + virtual int pre_direct_update_rows_init(List<Item> *update_fields) + { + return HA_ERR_WRONG_COMMAND; + } + virtual int direct_update_rows(ha_rows *update_rows __attribute__((unused)), + ha_rows *found_rows __attribute__((unused))) + { + return HA_ERR_WRONG_COMMAND; + } + virtual int pre_direct_update_rows() + { + return HA_ERR_WRONG_COMMAND; + } + + /* Perform initialization for a direct delete request */ +public: + int ha_direct_delete_rows(ha_rows *delete_rows); + virtual int direct_delete_rows_init() + { + return HA_ERR_WRONG_COMMAND; + } +private: + virtual int pre_direct_delete_rows_init() + { + return HA_ERR_WRONG_COMMAND; + } + virtual int direct_delete_rows(ha_rows *delete_rows __attribute__((unused))) + { + return HA_ERR_WRONG_COMMAND; + } + virtual int pre_direct_delete_rows() + { + 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; + } +protected: + virtual void start_bulk_insert(ha_rows rows, uint flags) {} + virtual int end_bulk_insert() { return 0; } + virtual int index_read(uchar * buf, const uchar * key, uint key_len, + enum ha_rkey_function find_flag) + { return HA_ERR_WRONG_COMMAND; } + virtual int index_read_last(uchar * buf, const uchar * key, uint key_len) + { + my_errno= HA_ERR_WRONG_COMMAND; + return HA_ERR_WRONG_COMMAND; + } + friend class ha_partition; + friend class ha_sequence; +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, const uchar *new_data, + ha_rows *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 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, + chf_create_flags 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; } + /* @return true if it's necessary to switch current statement log format from + STATEMENT to ROW if binary log format is MIXED and autoincrement values + are changed in the statement */ + virtual bool autoinc_lock_mode_stmt_unsafe() const + { return false; } + 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; + } + void set_table(TABLE* table_arg) { table= table_arg; } + 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; } + virtual bool partition_engine() { return 0;} + inline int ha_write_tmp_row(uchar *buf); + inline int ha_delete_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 check_result_t handler_index_cond_check(void* h_arg); + friend check_result_t handler_rowid_filter_check(void *h_arg); + + /** + Find unique record by index or unique constrain + + @param record record to find (also will be fillded with + actual record fields) + @param unique_ref index or unique constraiun number (depends + on what used in the engine + + @retval -1 Error + @retval 1 Not found + @retval 0 Found + */ + virtual int find_unique_row(uchar *record, uint unique_ref) + { return -1; /*unsupported */} + + bool native_versioned() const + { DBUG_ASSERT(ht); return partition_ht()->flags & HTON_NATIVE_SYS_VERSIONING; } + virtual void update_partition(uint part_id) + {} + + /** + Some engines can perform column type conversion with ALGORITHM=INPLACE. + These functions check for such possibility. + Implementation could be based on Field_xxx::is_equal() + */ + virtual bool can_convert_nocopy(const Field &, + const Column_definition &) const + { + return false; + } + /* If the table is using sql level unique constraints on some column */ + inline bool has_long_unique(); + + /* Used for ALTER TABLE. + Some engines can handle some differences in indexes by themself. */ + virtual Compare_keys compare_key_parts(const Field &old_field, + const Column_definition &new_field, + const KEY_PART_INFO &old_part, + const KEY_PART_INFO &new_part) const; + + +/* + If lower_case_table_names == 2 (case-preserving but case-insensitive + file system) and the storage is not HA_FILE_BASED, we need to provide + a lowercase file name for the engine. +*/ + inline bool needs_lower_case_filenames() + { + return (lower_case_table_names == 2 && !(ha_table_flags() & HA_FILE_BASED)); + } + + bool log_not_redoable_operation(const char *operation); + +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" +#include "group_by_handler.h" + +bool key_uses_partial_cols(TABLE_SHARE *table, uint keyno); + + /* Some extern variables used with handlers */ + +extern const LEX_CSTRING 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_CSTRING *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" : + db_type == view_pseudo_hton ? "VIEW" : hton_name(db_type)->str); +} + +static inline bool ha_check_storage_engine_flag(const handlerton *db_type, uint32 flag) +{ + return db_type && (db_type->flags & flag); +} + +static inline bool ha_storage_engine_is_enabled(const handlerton *db_type) +{ + return db_type && db_type->create; +} + +/* 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); +void ha_signal_ddl_recovery_done(); +bool ha_flush_logs(); +void ha_drop_database(const 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, bool skip_frm_file); +int ha_delete_table(THD *thd, handlerton *db_type, const char *path, + const LEX_CSTRING *db, const LEX_CSTRING *alias, + bool generate_warning); +int ha_delete_table_force(THD *thd, const char *path, const LEX_CSTRING *db, + const LEX_CSTRING *alias); + +void ha_prepare_for_backup(); +void ha_end_backup(); +void ha_pre_shutdown(); + +void ha_disable_internal_writes(bool disable); + +/* 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_CSTRING*> *tables; + + Discovered_table_list(THD *thd_arg, Dynamic_array<LEX_CSTRING*> *tables_arg, + const LEX_CSTRING *wild_arg); + Discovered_table_list(THD *thd_arg, Dynamic_array<LEX_CSTRING*> *tables_arg) + : thd(thd_arg), wild(NULL), with_temps(true), tables(tables_arg) {} + ~Discovered_table_list() = default; + + 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 +#ifndef DBUG_OFF + /* + Used to find unstable mtr tests querying + INFORMATION_SCHEMA.TABLES without ORDER BY. + */ + void sort_desc(); +#endif /* DBUG_OFF */ +}; + +int ha_discover_table(THD *thd, TABLE_SHARE *share); +int ha_discover_table_names(THD *thd, LEX_CSTRING *db, MY_DIR *dirp, + Discovered_table_list *result, bool reusable); +bool ha_table_exists(THD *thd, const LEX_CSTRING *db, + const LEX_CSTRING *table_name, + LEX_CUSTRING *table_version= 0, + LEX_CSTRING *partition_engine_name= 0, + handlerton **hton= 0, bool *is_sequence= 0); +bool ha_check_if_updates_are_ignored(THD *thd, handlerton *hton, + const char *op); +#endif /* MYSQL_SERVER */ + +/* 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); + +/* 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, MEM_ROOT *mem_root= NULL); +uint ha_recover_complete(HASH *commit_list, Binlog_offset *coord= NULL); + +/* 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); +#endif + +/* these are called by storage engines */ +void trans_register_ha(THD *thd, bool all, handlerton *ht, + ulonglong trxid); + +/* + 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); +void commit_checkpoint_notify_ha(void *cookie); + +inline const LEX_CSTRING *table_case_name(HA_CREATE_INFO *info, const LEX_CSTRING *name) +{ + return ((lower_case_table_names == 2 && info->alias.str) ? &info->alias : name); +} + +typedef bool Log_func(THD*, TABLE*, bool, const uchar*, const uchar*); +int binlog_log_row(TABLE* table, + const uchar *before_record, + const uchar *after_record, + Log_func *log_func); + +/** + @def MYSQL_TABLE_IO_WAIT + Instrumentation helper for table io_waits. + Note that this helper is intended to be used from + within the handler class only, as it uses members + from @c handler + Performance schema events are instrumented as follows: + - in non batch mode, one event is generated per call + - in batch mode, the number of rows affected is saved + in @c m_psi_numrows, so that @c end_psi_batch_mode() + generates a single event for the batch. + @param OP the table operation to be performed + @param INDEX the table index used if any, or MAX_KEY. + @param PAYLOAD instrumented code to execute + @sa handler::end_psi_batch_mode. +*/ +#ifdef HAVE_PSI_TABLE_INTERFACE + #define MYSQL_TABLE_IO_WAIT(OP, INDEX, RESULT, PAYLOAD) \ + { \ + if (m_psi != NULL) \ + { \ + switch (m_psi_batch_mode) \ + { \ + case PSI_BATCH_MODE_NONE: \ + { \ + PSI_table_locker *sub_locker= NULL; \ + PSI_table_locker_state reentrant_safe_state; \ + sub_locker= PSI_TABLE_CALL(start_table_io_wait) \ + (& reentrant_safe_state, m_psi, OP, INDEX, \ + __FILE__, __LINE__); \ + PAYLOAD \ + if (sub_locker != NULL) \ + PSI_TABLE_CALL(end_table_io_wait) \ + (sub_locker, 1); \ + break; \ + } \ + case PSI_BATCH_MODE_STARTING: \ + { \ + m_psi_locker= PSI_TABLE_CALL(start_table_io_wait) \ + (& m_psi_locker_state, m_psi, OP, INDEX, \ + __FILE__, __LINE__); \ + PAYLOAD \ + if (!RESULT) \ + m_psi_numrows++; \ + m_psi_batch_mode= PSI_BATCH_MODE_STARTED; \ + break; \ + } \ + case PSI_BATCH_MODE_STARTED: \ + default: \ + { \ + DBUG_ASSERT(m_psi_batch_mode \ + == PSI_BATCH_MODE_STARTED); \ + PAYLOAD \ + if (!RESULT) \ + m_psi_numrows++; \ + break; \ + } \ + } \ + } \ + else \ + { \ + PAYLOAD \ + } \ + } +#else + #define MYSQL_TABLE_IO_WAIT(OP, INDEX, RESULT, PAYLOAD) \ + PAYLOAD +#endif + +#define TABLE_IO_WAIT(TRACKER, OP, INDEX, RESULT, PAYLOAD) \ + { \ + Exec_time_tracker *this_tracker; \ + if (unlikely((this_tracker= tracker))) \ + tracker->start_tracking(table->in_use); \ + \ + MYSQL_TABLE_IO_WAIT(OP, INDEX, RESULT, PAYLOAD); \ + \ + if (unlikely(this_tracker)) \ + tracker->stop_tracking(table->in_use); \ + } +void print_keydup_error(TABLE *table, KEY *key, const char *msg, myf errflag); +void print_keydup_error(TABLE *table, KEY *key, myf errflag); + +int del_global_index_stat(THD *thd, TABLE* table, KEY* key_info); +int del_global_table_stat(THD *thd, const LEX_CSTRING *db, const LEX_CSTRING *table); +uint ha_count_rw_all(THD *thd, Ha_trx_info **ptr_ha_info); +bool non_existing_table_error(int error); +uint ha_count_rw_2pc(THD *thd, bool all); +uint ha_check_and_coalesce_trx_read_only(THD *thd, Ha_trx_info *ha_list, + bool all); + +#endif /* HANDLER_INCLUDED */ |