trx0rseg.h
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上传日期:2022-05-23
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- /******************************************************
- 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{
- /*--------------------------------------------------------*/
- ulint id; /* rollback segment id == the index of
- 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 */
- ulint space; /* space where the rollback segment is
- 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
- #endif