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/*****************************************************************************
Copyright (c) 1996, 2015, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2017, MariaDB Corporation.
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 Street, Suite 500, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file include/trx0rseg.h
Rollback segment
Created 3/26/1996 Heikki Tuuri
*******************************************************/
#ifndef trx0rseg_h
#define trx0rseg_h
#include "trx0types.h"
#include "trx0sys.h"
#include "fut0lst.h"
#include <vector>
/** Gets a rollback segment header.
@param[in] space space where placed
@param[in] page_no page number of the header
@param[in,out] mtr mini-transaction
@return rollback segment header, page x-latched */
UNIV_INLINE
trx_rsegf_t*
trx_rsegf_get(
ulint space,
ulint page_no,
mtr_t* mtr);
/** Gets a newly created rollback segment header.
@param[in] space space where placed
@param[in] page_no page number of the header
@param[in,out] mtr mini-transaction
@return rollback segment header, page x-latched */
UNIV_INLINE
trx_rsegf_t*
trx_rsegf_get_new(
ulint space,
ulint page_no,
mtr_t* mtr);
/***************************************************************//**
Gets the file page number of the nth undo log slot.
@return page number of the undo log segment */
UNIV_INLINE
ulint
trx_rsegf_get_nth_undo(
/*===================*/
trx_rsegf_t* rsegf, /*!< in: rollback segment header */
ulint n, /*!< in: index of slot */
mtr_t* mtr); /*!< in: mtr */
/***************************************************************//**
Sets the file page number of the nth undo log slot. */
UNIV_INLINE
void
trx_rsegf_set_nth_undo(
/*===================*/
trx_rsegf_t* rsegf, /*!< in: rollback segment header */
ulint n, /*!< in: index of slot */
ulint page_no,/*!< in: page number of the undo log segment */
mtr_t* mtr); /*!< in: mtr */
/****************************************************************//**
Looks for a free slot for an undo log segment.
@return slot index or ULINT_UNDEFINED if not found */
UNIV_INLINE
ulint
trx_rsegf_undo_find_free(
/*=====================*/
trx_rsegf_t* rsegf, /*!< in: rollback segment header */
mtr_t* mtr); /*!< in: mtr */
/** Get a rollback segment.
@param[in] id rollback segment id
@return rollback segment */
UNIV_INLINE
trx_rseg_t*
trx_rseg_get_on_id(ulint id)
{
ut_a(id < TRX_SYS_N_RSEGS);
return(trx_sys->rseg_array[id]);
}
/** Creates a rollback segment header.
This function is called only when a new rollback segment is created in
the database.
@param[in] space space id
@param[in] max_size max size in pages
@param[in] rseg_slot_no rseg id == slot number in trx sys
@param[in,out] mtr mini-transaction
@return page number of the created segment, FIL_NULL if fail */
ulint
trx_rseg_header_create(
ulint space,
ulint max_size,
ulint rseg_slot_no,
mtr_t* mtr);
/** Initialize the rollback segments in memory at database startup. */
void
trx_rseg_array_init();
/** Free a rollback segment in memory. */
void
trx_rseg_mem_free(trx_rseg_t* rseg);
/*********************************************************************
Creates a rollback segment. */
trx_rseg_t*
trx_rseg_create(
/*============*/
ulint space_id, /*!< in: id of UNDO tablespace */
ulint nth_free_slot); /*!< in: allocate nth free slot.
0 means next free slots. */
/********************************************************************
Get the number of unique rollback tablespaces in use except space id 0.
The last space id will be the sentinel value ULINT_UNDEFINED. The array
will be sorted on space id. Note: space_ids should have have space for
TRX_SYS_N_RSEGS + 1 elements.
@return number of unique rollback tablespaces in use. */
ulint
trx_rseg_get_n_undo_tablespaces(
/*============================*/
ulint* space_ids); /*!< out: array of space ids of
UNDO tablespaces */
/* Number of undo log slots in a rollback segment file copy */
#define TRX_RSEG_N_SLOTS (UNIV_PAGE_SIZE / 16)
/* Maximum number of transactions supported by a single rollback segment */
#define TRX_RSEG_MAX_N_TRXS (TRX_RSEG_N_SLOTS / 2)
/** The rollback segment memory object */
struct trx_rseg_t {
/*--------------------------------------------------------*/
/** rollback segment id == the index of its slot in the trx
system file copy */
ulint id;
/** mutex protecting the fields in this struct except id,space,page_no
which are constant */
RsegMutex mutex;
/** space where the rollback segment header is placed */
ulint space;
/** page number of the rollback segment header */
ulint page_no;
/** maximum allowed size in pages */
ulint max_size;
/** current size in pages */
ulint curr_size;
/*--------------------------------------------------------*/
/* Fields for undo logs */
/** List of undo logs */
UT_LIST_BASE_NODE_T(trx_undo_t) undo_list;
/** List of undo log segments cached for fast reuse */
UT_LIST_BASE_NODE_T(trx_undo_t) undo_cached;
/*--------------------------------------------------------*/
/** Page number of the last not yet purged log header in the history
list; FIL_NULL if all list purged */
ulint last_page_no;
/** Byte offset of the last not yet purged log header */
ulint last_offset;
/** Transaction number of the last not yet purged log */
trx_id_t last_trx_no;
/** TRUE if the last not yet purged log needs purging */
ibool last_del_marks;
/** Reference counter to track rseg allocated transactions. */
ulint trx_ref_count;
/** If true, then skip allocating this rseg as it reside in
UNDO-tablespace marked for truncate. */
bool skip_allocation;
};
/* Undo log segment slot in a rollback segment header */
/*-------------------------------------------------------------*/
#define TRX_RSEG_SLOT_PAGE_NO 0 /* Page number of the header page of
an undo log segment */
/*-------------------------------------------------------------*/
/* Slot size */
#define TRX_RSEG_SLOT_SIZE 4
/* The offset of the rollback segment header on its page */
#define TRX_RSEG FSEG_PAGE_DATA
/* Transaction rollback segment header */
/*-------------------------------------------------------------*/
#define TRX_RSEG_MAX_SIZE 0 /* Maximum allowed size for rollback
segment in pages */
#define TRX_RSEG_HISTORY_SIZE 4 /* Number of file pages occupied
by the logs in the history list */
#define TRX_RSEG_HISTORY 8 /* The update undo logs for committed
transactions */
#define TRX_RSEG_FSEG_HEADER (8 + FLST_BASE_NODE_SIZE)
/* Header for the file segment where
this page is placed */
#define TRX_RSEG_UNDO_SLOTS (8 + FLST_BASE_NODE_SIZE + FSEG_HEADER_SIZE)
/* Undo log segment slots */
/*-------------------------------------------------------------*/
#ifndef UNIV_NONINL
#include "trx0rseg.ic"
#endif
#endif
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