release/src/router/mysql/storage/innodb_plugin/include/trx0rseg.h

   1 /*****************************************************************************
   2
   3 Copyright (c) 1996, 2010, Innobase Oy. All Rights Reserved.
   4
   5 This program is free software; you can redistribute it and/or modify it under
   6 the terms of the GNU General Public License as published by the Free Software
   7 Foundation; version 2 of the License.
   8
   9 This program is distributed in the hope that it will be useful, but WITHOUT
  10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  11 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
  12
  13 You should have received a copy of the GNU General Public License along with
  14 this program; if not, write to the Free Software Foundation, Inc.,
  15 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  16
  17 *****************************************************************************/
  18
  19 /**************************************************//**
  20 @file include/trx0rseg.h
  21 Rollback segment
  22
  23 Created 3/26/1996 Heikki Tuuri
  24 *******************************************************/
  25
  26 #ifndef trx0rseg_h
  27 #define trx0rseg_h
  28
  29 #include "univ.i"
  30 #include "trx0types.h"
  31 #include "trx0sys.h"
  32
  33 /******************************************************************//**
  34 Gets a rollback segment header.
  35 @return rollback segment header, page x-latched */
  36 UNIV_INLINE
  37 trx_rsegf_t*
  38 trx_rsegf_get(
  39 /*==========*/
  40         ulint   space,          /*!< in: space where placed */
  41         ulint   zip_size,       /*!< in: compressed page size in bytes
  42                                 or 0 for uncompressed pages */
  43         ulint   page_no,        /*!< in: page number of the header */
  44         mtr_t*  mtr);           /*!< in: mtr */
  45 /******************************************************************//**
  46 Gets a newly created rollback segment header.
  47 @return rollback segment header, page x-latched */
  48 UNIV_INLINE
  49 trx_rsegf_t*
  50 trx_rsegf_get_new(
  51 /*==============*/
  52         ulint   space,          /*!< in: space where placed */
  53         ulint   zip_size,       /*!< in: compressed page size in bytes
  54                                 or 0 for uncompressed pages */
  55         ulint   page_no,        /*!< in: page number of the header */
  56         mtr_t*  mtr);           /*!< in: mtr */
  57 /***************************************************************//**
  58 Gets the file page number of the nth undo log slot.
  59 @return page number of the undo log segment */
  60 UNIV_INLINE
  61 ulint
  62 trx_rsegf_get_nth_undo(
  63 /*===================*/
  64         trx_rsegf_t*    rsegf,  /*!< in: rollback segment header */
  65         ulint           n,      /*!< in: index of slot */
  66         mtr_t*          mtr);   /*!< in: mtr */
  67 /***************************************************************//**
  68 Sets the file page number of the nth undo log slot. */
  69 UNIV_INLINE
  70 void
  71 trx_rsegf_set_nth_undo(
  72 /*===================*/
  73         trx_rsegf_t*    rsegf,  /*!< in: rollback segment header */
  74         ulint           n,      /*!< in: index of slot */
  75         ulint           page_no,/*!< in: page number of the undo log segment */
  76         mtr_t*          mtr);   /*!< in: mtr */
  77 /****************************************************************//**
  78 Looks for a free slot for an undo log segment.
  79 @return slot index or ULINT_UNDEFINED if not found */
  80 UNIV_INLINE
  81 ulint
  82 trx_rsegf_undo_find_free(
  83 /*=====================*/
  84         trx_rsegf_t*    rsegf,  /*!< in: rollback segment header */
  85         mtr_t*          mtr);   /*!< in: mtr */
  86 /******************************************************************//**
  87 Looks for a rollback segment, based on the rollback segment id.
  88 @return rollback segment */
  89 UNIV_INTERN
  90 trx_rseg_t*
  91 trx_rseg_get_on_id(
  92 /*===============*/
  93         ulint   id);    /*!< in: rollback segment id */
  94 /****************************************************************//**
  95 Creates a rollback segment header. This function is called only when
  96 a new rollback segment is created in the database.
  97 @return page number of the created segment, FIL_NULL if fail */
  98 UNIV_INTERN
  99 ulint
 100 trx_rseg_header_create(
 101 /*===================*/
 102         ulint   space,          /*!< in: space id */
 103         ulint   zip_size,       /*!< in: compressed page size in bytes
 104                                 or 0 for uncompressed pages */
 105         ulint   max_size,       /*!< in: max size in pages */
 106         ulint*  slot_no,        /*!< out: rseg id == slot number in trx sys */
 107         mtr_t*  mtr);           /*!< in: mtr */
 108 /*********************************************************************//**
 109 Creates the memory copies for rollback segments and initializes the
 110 rseg list and array in trx_sys at a database startup. */
 111 UNIV_INTERN
 112 void
 113 trx_rseg_list_and_array_init(
 114 /*=========================*/
 115         trx_sysf_t*     sys_header,     /*!< in: trx system header */
 116         mtr_t*          mtr);           /*!< in: mtr */
 117 /***************************************************************************
 118 Free's an instance of the rollback segment in memory. */
 119 UNIV_INTERN
 120 void
 121 trx_rseg_mem_free(
 122 /*==============*/
 123         trx_rseg_t*     rseg);          /* in, own: instance to free */
 124
 125
 126 /* Number of undo log slots in a rollback segment file copy */
 127 #define TRX_RSEG_N_SLOTS        (UNIV_PAGE_SIZE / 16)
 128
 129 /* Maximum number of transactions supported by a single rollback segment */
 130 #define TRX_RSEG_MAX_N_TRXS     (TRX_RSEG_N_SLOTS / 2)
 131
 132 /* The rollback segment memory object */
 133 struct trx_rseg_struct{
 134         /*--------------------------------------------------------*/
 135         ulint           id;     /*!< rollback segment id == the index of
 136                                 its slot in the trx system file copy */
 137         mutex_t         mutex;  /*!< mutex protecting the fields in this
 138                                 struct except id, which is constant */
 139         ulint           space;  /*!< space where the rollback segment is
 140                                 header is placed */
 141         ulint           zip_size;/* compressed page size of space
 142                                 in bytes, or 0 for uncompressed spaces */
 143         ulint           page_no;/* page number of the rollback segment
 144                                 header */
 145         ulint           max_size;/* maximum allowed size in pages */
 146         ulint           curr_size;/* current size in pages */
 147         /*--------------------------------------------------------*/
 148         /* Fields for update undo logs */
 149         UT_LIST_BASE_NODE_T(trx_undo_t) update_undo_list;
 150                                         /* List of update undo logs */
 151         UT_LIST_BASE_NODE_T(trx_undo_t) update_undo_cached;
 152                                         /* List of update undo log segments
 153                                         cached for fast reuse */
 154         /*--------------------------------------------------------*/
 155         /* Fields for insert undo logs */
 156         UT_LIST_BASE_NODE_T(trx_undo_t) insert_undo_list;
 157                                         /* List of insert undo logs */
 158         UT_LIST_BASE_NODE_T(trx_undo_t) insert_undo_cached;
 159                                         /* List of insert undo log segments
 160                                         cached for fast reuse */
 161         /*--------------------------------------------------------*/
 162         ulint           last_page_no;   /*!< Page number of the last not yet
 163                                         purged log header in the history list;
 164                                         FIL_NULL if all list purged */
 165         ulint           last_offset;    /*!< Byte offset of the last not yet
 166                                         purged log header */
 167         trx_id_t        last_trx_no;    /*!< Transaction number of the last not
 168                                         yet purged log */
 169         ibool           last_del_marks; /*!< TRUE if the last not yet purged log
 170                                         needs purging */
 171         /*--------------------------------------------------------*/
 172         UT_LIST_NODE_T(trx_rseg_t) rseg_list;
 173                                         /* the list of the rollback segment
 174                                         memory objects */
 175 };
 176
 177 /* Undo log segment slot in a rollback segment header */
 178 /*-------------------------------------------------------------*/
 179 #define TRX_RSEG_SLOT_PAGE_NO   0       /* Page number of the header page of
 180                                         an undo log segment */
 181 /*-------------------------------------------------------------*/
 182 /* Slot size */
 183 #define TRX_RSEG_SLOT_SIZE      4
 184
 185 /* The offset of the rollback segment header on its page */
 186 #define TRX_RSEG                FSEG_PAGE_DATA
 187
 188 /* Transaction rollback segment header */
 189 /*-------------------------------------------------------------*/
 190 #define TRX_RSEG_MAX_SIZE       0       /* Maximum allowed size for rollback
 191                                         segment in pages */
 192 #define TRX_RSEG_HISTORY_SIZE   4       /* Number of file pages occupied
 193                                         by the logs in the history list */
 194 #define TRX_RSEG_HISTORY        8       /* The update undo logs for committed
 195                                         transactions */
 196 #define TRX_RSEG_FSEG_HEADER    (8 + FLST_BASE_NODE_SIZE)
 197                                         /* Header for the file segment where
 198                                         this page is placed */
 199 #define TRX_RSEG_UNDO_SLOTS     (8 + FLST_BASE_NODE_SIZE + FSEG_HEADER_SIZE)
 200                                         /* Undo log segment slots */
 201 /*-------------------------------------------------------------*/
 202
 203 #ifndef UNIV_NONINL
 204 #include "trx0rseg.ic"
 205 #endif
 206
 207 #endif