trx0rseg.h 6.64 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
/******************************************************
Rollback segment

(c) 1996 Innobase Oy

Created 3/26/1996 Heikki Tuuri
*******************************************************/

#ifndef trx0rseg_h
#define trx0rseg_h

#include "univ.i"
#include "trx0types.h"
#include "trx0sys.h"

/**********************************************************************
Gets a rollback segment header. */
UNIV_INLINE
trx_rsegf_t*
trx_rsegf_get(
/*==========*/
				/* out: rollback segment header, page
				x-latched */
	ulint	space,		/* in: space where placed */
	ulint	page_no,	/* in: page number of the header */
	mtr_t*	mtr);		/* in: mtr */
/**********************************************************************
Gets a newly created rollback segment header. */
UNIV_INLINE
trx_rsegf_t*
trx_rsegf_get_new(
/*==============*/
				/* out: rollback segment header, page
				x-latched */
	ulint	space,		/* in: space where placed */
	ulint	page_no,	/* in: page number of the header */
	mtr_t*	mtr);		/* in: mtr */
/*******************************************************************
Gets the file page number of the nth undo log slot. */
UNIV_INLINE
ulint
trx_rsegf_get_nth_undo(
/*===================*/
				/* out: page number of the undo log segment */
	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. */
UNIV_INLINE
ulint
trx_rsegf_undo_find_free(
/*=====================*/
				/* out: slot index or ULINT_UNDEFINED if not
				found */
	trx_rsegf_t*	rsegf,	/* in: rollback segment header */
	mtr_t*		mtr);	/* in: mtr */
/**********************************************************************
Looks for a rollback segment, based on the rollback segment id. */

trx_rseg_t*
trx_rseg_get_on_id(
/*===============*/
			/* out: rollback segment */
	ulint	id);	/* in: rollback segment id */
/********************************************************************
Creates a rollback segment header. This function is called only when
a new rollback segment is created in the database. */

ulint
trx_rseg_header_create(
/*===================*/
				/* out: page number of the created segment,
				FIL_NULL if fail */
	ulint	space,		/* in: space id */
	ulint	max_size,	/* in: max size in pages */
	ulint*	slot_no,	/* out: rseg id == slot number in trx sys */
	mtr_t*	mtr);		/* in: mtr */
/*************************************************************************
Creates the memory copies for rollback segments and initializes the
rseg list and array in trx_sys at a database startup. */

void
trx_rseg_list_and_array_init(
/*=========================*/
	trx_sysf_t*	sys_header,	/* in: trx system header */
	mtr_t*		mtr);		/* in: mtr */
/********************************************************************
Creates a new rollback segment to the database. */

trx_rseg_t*
trx_rseg_create(
/*============*/
				/* out: the created segment object, NULL if
				fail */
	ulint	space,		/* in: space id */
	ulint	max_size,	/* in: max size in pages */
	ulint*	id,		/* out: rseg id */
	mtr_t*	mtr);		/* in: mtr */


/* Number of undo log slots in a rollback segment file copy */
#define TRX_RSEG_N_SLOTS	1024

/* 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_struct{
	/*--------------------------------------------------------*/
121
	ulint		id;	/* rollback segment id == the index of
122 123 124 125 126
				its slot in the trx system file copy */
	mutex_t		mutex;	/* mutex protecting the fields in this
				struct except id; NOTE that the latching
				order must always be kernel mutex ->
				rseg mutex */
127
	ulint		space;	/* space where the rollback segment is
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192
				header is placed */
	ulint		page_no;/* page number of the rollback segment
				header */
	ulint		max_size;/* maximum allowed size in pages */
	ulint		curr_size;/* current size in pages */
	/*--------------------------------------------------------*/
	/* Fields for update undo logs */
	UT_LIST_BASE_NODE_T(trx_undo_t) update_undo_list;
					/* List of update undo logs */
	UT_LIST_BASE_NODE_T(trx_undo_t) update_undo_cached;
					/* List of update undo log segments
					cached for fast reuse */
	/*--------------------------------------------------------*/
	/* Fields for insert undo logs */
	UT_LIST_BASE_NODE_T(trx_undo_t) insert_undo_list;
					/* List of insert undo logs */
	UT_LIST_BASE_NODE_T(trx_undo_t) insert_undo_cached;
					/* List of insert undo log segments
					cached for fast reuse */
	/*--------------------------------------------------------*/
	ulint		last_page_no;	/* Page number of the last not yet
					purged log header in the history list;
					FIL_NULL if all list purged */
	ulint		last_offset;	/* Byte offset of the last not yet
					purged log header */
	dulint		last_trx_no;	/* Transaction number of the last not
					yet purged log */
	ibool		last_del_marks;	/* TRUE if the last not yet purged log
					needs purging */
	/*--------------------------------------------------------*/
	UT_LIST_NODE_T(trx_rseg_t) rseg_list;
					/* the list of the rollback segment
					memory objects */
};

/* 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

193
#endif