/***************************************************************************** Copyright (c) 1996, 2011, 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 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 "univ.i" #include "trx0types.h" #include "trx0sys.h" #include "ut0bh.h" /******************************************************************//** Gets a rollback segment header. @return rollback segment header, page x-latched */ UNIV_INLINE trx_rsegf_t* trx_rsegf_get( /*==========*/ ulint space, /*!< in: space where placed */ ulint zip_size, /*!< in: compressed page size in bytes or 0 for uncompressed pages */ ulint page_no, /*!< in: page number of the header */ mtr_t* mtr); /*!< in: mtr */ /******************************************************************//** Gets a newly created rollback segment header. @return rollback segment header, page x-latched */ UNIV_INLINE trx_rsegf_t* trx_rsegf_get_new( /*==============*/ ulint space, /*!< in: space where placed */ ulint zip_size, /*!< in: compressed page size in bytes or 0 for uncompressed pages */ 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. @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 */ /******************************************************************//** Looks for a rollback segment, based on the rollback segment id. @return rollback segment */ UNIV_INLINE trx_rseg_t* trx_rseg_get_on_id( /*===============*/ 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. @return page number of the created segment, FIL_NULL if fail */ UNIV_INTERN ulint trx_rseg_header_create( /*===================*/ ulint space, /*!< in: space id */ ulint zip_size, /*!< in: compressed page size in bytes or 0 for uncompressed pages */ ulint max_size, /*!< in: max size in pages */ ulint rseg_slot_no, /*!< in: rseg id == slot number in trx sys */ mtr_t* mtr); /*!< in: mtr */ /*********************************************************************//** Creates the memory copies for rollback segments and initializes the rseg array in trx_sys at a database startup. */ UNIV_INTERN void trx_rseg_array_init( /*================*/ trx_sysf_t* sys_header, /*!< in/out: trx system header */ ib_bh_t* ib_bh, /*!< in: rseg queue */ mtr_t* mtr); /*!< in/out: mtr */ /*************************************************************************** Free's an instance of the rollback segment in memory. */ UNIV_INTERN void trx_rseg_mem_free( /*==============*/ trx_rseg_t* rseg); /*!< in, own: instance to free */ /********************************************************************* Creates a rollback segment. */ UNIV_INTERN trx_rseg_t* trx_rseg_create( /*============*/ ulint space); /*!< in: id of UNDO tablespace */ /******************************************************************** 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. */ UNIV_INTERN 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{ /*--------------------------------------------------------*/ ulint id; /*!< rollback segment id == the index of its slot in the trx system file copy */ ib_mutex_t mutex; /*!< mutex protecting the fields in this struct except id, which is constant */ ulint space; /*!< space where the rollback segment is header is placed */ ulint zip_size;/* compressed page size of space in bytes, or 0 for uncompressed spaces */ 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 */ trx_id_t 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 */ }; /** For prioritising the rollback segments for purge. */ struct rseg_queue_t { trx_id_t trx_no; /*!< trx_rseg_t::last_trx_no */ trx_rseg_t* rseg; /*!< Rollback segment */ }; /* 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