polardbxengine/storage/innobase/include/row0vers.h

146 lines
7.0 KiB
C++

/*****************************************************************************
Copyright (c) 1997, 2018, Oracle and/or its affiliates. All Rights Reserved.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License, version 2.0, as published by the
Free Software Foundation.
This program is also distributed with certain software (including but not
limited to OpenSSL) that is licensed under separate terms, as designated in a
particular file or component or in included license documentation. The authors
of MySQL hereby grant you an additional permission to link the program and
your derivative works with the separately licensed software that they have
included with MySQL.
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, version 2.0,
for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*****************************************************************************/
/** @file include/row0vers.h
Row versions
Created 2/6/1997 Heikki Tuuri
*******************************************************/
#ifndef row0vers_h
#define row0vers_h
#include "data0data.h"
#include "dict0mem.h"
#include "dict0types.h"
#include "lob0undo.h"
#include "mtr0mtr.h"
#include "que0types.h"
#include "rem0types.h"
#include "trx0types.h"
#include "univ.i"
// Forward declaration
struct txn_rec_t;
namespace lizard {
class Vision;
} // namespace lizard
/** Finds out if an active transaction has inserted or modified a secondary
index record.
@return 0 if committed, else the active transaction id;
NOTE that this function can return false positives but never false
negatives. The caller must confirm all positive results by calling
trx_is_active() while holding lock_sys->mutex. */
trx_t *row_vers_impl_x_locked(
const rec_t *rec, /*!< in: record in a secondary index */
const dict_index_t *index, /*!< in: the secondary index */
const ulint *offsets); /*!< in: rec_get_offsets(rec, index) */
/** Finds out if we must preserve a delete marked earlier version of a clustered
index record, because it is >= the purge view.
@param[in] trx_id transaction id in the version
@param[in] name table name
@param[in,out] mtr mini transaction holding the latch on the
clustered index record; it will also hold
the latch on purge_view
@return true if earlier version should be preserved */
ibool row_vers_must_preserve_del_marked(txn_rec_t *txn_rec,
const table_name_t &name, mtr_t *mtr);
/** Finds out if a version of the record, where the version >= the current
purge view, should have ientry as its secondary index entry. We check
if there is any not delete marked version of the record where the trx
id >= purge view, and the secondary index entry == ientry; exactly in
this case we return TRUE.
@return true if earlier version should have */
ibool row_vers_old_has_index_entry(
ibool also_curr, /*!< in: TRUE if also rec is included in the
versions to search; otherwise only versions
prior to it are searched */
const rec_t *rec, /*!< in: record in the clustered index; the
caller must have a latch on the page */
mtr_t *mtr, /*!< in: mtr holding the latch on rec; it will
also hold the latch on purge_view */
dict_index_t *index, /*!< in: the secondary index */
const dtuple_t *ientry, /*!< in: the secondary index entry */
roll_ptr_t roll_ptr, /*!< in: roll_ptr for the purge record */
trx_id_t trx_id); /*!< in: transaction ID on the purging record */
/** Constructs the version of a clustered index record which a consistent
read should see. We assume that the trx id stored in rec is such that
the consistent read should not see rec in its present version.
@param[in] rec record in a clustered index; the caller must have a latch
on the page; this latch locks the top of the stack of
versions of this records
@param[in] mtr mtr holding the latch on rec; it will also hold the latch
on purge_view
@param[in] index the clustered index
@param[in] offsets offsets returned by rec_get_offsets(rec, index)
@param[in] view the consistent read view
@param[in,out] offset_heap memory heap from which the offsets are
allocated
@param[in] in_heap memory heap from which the memory for *old_vers is
allocated; memory for possible intermediate versions
is allocated and freed locally within the function
@param[out] old_vers old version, or NULL if the history is missing or
the record does not exist in the view, that is, it
was freshly inserted afterwards.
@param[out] vrow reports virtual column info if any
@param[in] lob_undo undo log to be applied to blobs.
@return DB_SUCCESS or DB_MISSING_HISTORY */
dberr_t row_vers_build_for_consistent_read(
const rec_t *rec, mtr_t *mtr, dict_index_t *index, ulint **offsets,
const lizard::Vision *vision, mem_heap_t **offset_heap, mem_heap_t *in_heap,
rec_t **old_vers, const dtuple_t **vrow, lob::undo_vers_t *lob_undo);
/** Constructs the last committed version of a clustered index record,
which should be seen by a semi-consistent read. */
void row_vers_build_for_semi_consistent_read(
const rec_t *rec, /*!< in: record in a clustered index; the
caller must have a latch on the page; this
latch locks the top of the stack of versions
of this records */
mtr_t *mtr, /*!< in: mtr holding the latch on rec */
dict_index_t *index, /*!< in: the clustered index */
ulint **offsets, /*!< in/out: offsets returned by
rec_get_offsets(rec, index) */
mem_heap_t **offset_heap, /*!< in/out: memory heap from which
the offsets are allocated */
mem_heap_t *in_heap, /*!< in: memory heap from which the memory for
*old_vers is allocated; memory for possible
intermediate versions is allocated and freed
locally within the function */
const rec_t **old_vers, /*!< out: rec, old version, or NULL if the
record does not exist in the view, that is,
it was freshly inserted afterwards */
const dtuple_t **vrow); /*!< out: holds virtual column info if any
is updated in the view */
#include "row0vers.ic"
#endif