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| -rw-r--r-- | storage/innobase/include/btr0pcur.inl | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/storage/innobase/include/btr0pcur.inl b/storage/innobase/include/btr0pcur.inl new file mode 100644 index 00000000..b827d70d --- /dev/null +++ b/storage/innobase/include/btr0pcur.inl @@ -0,0 +1,372 @@ +/***************************************************************************** + +Copyright (c) 1996, 2015, Oracle and/or its affiliates. All Rights Reserved. +Copyright (c) 2015, 2023, 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, Fifth Floor, Boston, MA 02110-1335 USA + +*****************************************************************************/ + +/**************************************************//** +@file include/btr0pcur.ic +The index tree persistent cursor + +Created 2/23/1996 Heikki Tuuri +*******************************************************/ + + +/*********************************************************//** +Gets the rel_pos field for a cursor whose position has been stored. +@return BTR_PCUR_ON, ... */ +UNIV_INLINE +ulint +btr_pcur_get_rel_pos( +/*=================*/ + const btr_pcur_t* cursor) /*!< in: persistent cursor */ +{ + ut_ad(cursor); + ut_ad(cursor->old_rec); + ut_ad(cursor->pos_state == BTR_PCUR_WAS_POSITIONED + || cursor->pos_state == BTR_PCUR_IS_POSITIONED); + + return(cursor->rel_pos); +} + +/**************************************************************//** +Gets the up_match value for a pcur after a search. +@return number of matched fields at the cursor or to the right if +search mode was PAGE_CUR_GE, otherwise undefined */ +UNIV_INLINE +ulint +btr_pcur_get_up_match( +/*==================*/ + const btr_pcur_t* cursor) /*!< in: persistent cursor */ +{ + const btr_cur_t* btr_cursor; + + ut_ad((cursor->pos_state == BTR_PCUR_WAS_POSITIONED) + || (cursor->pos_state == BTR_PCUR_IS_POSITIONED)); + + btr_cursor = btr_pcur_get_btr_cur(cursor); + + ut_ad(btr_cursor->up_match != ULINT_UNDEFINED); + + return(btr_cursor->up_match); +} + +/**************************************************************//** +Gets the low_match value for a pcur after a search. +@return number of matched fields at the cursor or to the right if +search mode was PAGE_CUR_LE, otherwise undefined */ +UNIV_INLINE +ulint +btr_pcur_get_low_match( +/*===================*/ + const btr_pcur_t* cursor) /*!< in: persistent cursor */ +{ + const btr_cur_t* btr_cursor; + + ut_ad((cursor->pos_state == BTR_PCUR_WAS_POSITIONED) + || (cursor->pos_state == BTR_PCUR_IS_POSITIONED)); + + btr_cursor = btr_pcur_get_btr_cur(cursor); + ut_ad(btr_cursor->low_match != ULINT_UNDEFINED); + + return(btr_cursor->low_match); +} + +/*********************************************************//** +Checks if the persistent cursor is after the last user record on +a page. */ +UNIV_INLINE +ibool +btr_pcur_is_after_last_on_page( +/*===========================*/ + const btr_pcur_t* cursor) /*!< in: persistent cursor */ +{ + ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED); + ut_ad(cursor->latch_mode != BTR_NO_LATCHES); + + return(page_cur_is_after_last(btr_pcur_get_page_cur(cursor))); +} + +/*********************************************************//** +Checks if the persistent cursor is before the first user record on +a page. */ +UNIV_INLINE +ibool +btr_pcur_is_before_first_on_page( +/*=============================*/ + const btr_pcur_t* cursor) /*!< in: persistent cursor */ +{ + ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED); + ut_ad(cursor->latch_mode != BTR_NO_LATCHES); + + return(page_cur_is_before_first(btr_pcur_get_page_cur(cursor))); +} + +/*********************************************************//** +Checks if the persistent cursor is on a user record. */ +UNIV_INLINE +ibool +btr_pcur_is_on_user_rec( +/*====================*/ + const btr_pcur_t* cursor) /*!< in: persistent cursor */ +{ + return !btr_pcur_is_before_first_on_page(cursor) && + !btr_pcur_is_after_last_on_page(cursor); +} + +/*********************************************************//** +Checks if the persistent cursor is before the first user record in +the index tree. */ +static inline bool btr_pcur_is_before_first_in_tree(btr_pcur_t* cursor) +{ + ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED); + ut_ad(cursor->latch_mode != BTR_NO_LATCHES); + + return !page_has_prev(btr_pcur_get_page(cursor)) + && page_cur_is_before_first(btr_pcur_get_page_cur(cursor)); +} + +/*********************************************************//** +Checks if the persistent cursor is after the last user record in +the index tree. */ +static inline bool btr_pcur_is_after_last_in_tree(btr_pcur_t* cursor) +{ + ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED); + ut_ad(cursor->latch_mode != BTR_NO_LATCHES); + + return !page_has_next(btr_pcur_get_page(cursor)) + && page_cur_is_after_last(btr_pcur_get_page_cur(cursor)); +} + +/*********************************************************//** +Moves the persistent cursor to the next record on the same page. */ +UNIV_INLINE +rec_t* +btr_pcur_move_to_next_on_page( +/*==========================*/ + btr_pcur_t* cursor) /*!< in/out: persistent cursor */ +{ + ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED); + ut_ad(cursor->latch_mode != BTR_NO_LATCHES); + + cursor->old_rec = nullptr; + return page_cur_move_to_next(btr_pcur_get_page_cur(cursor)); +} + +/*********************************************************//** +Moves the persistent cursor to the previous record on the same page. */ +UNIV_INLINE +rec_t* +btr_pcur_move_to_prev_on_page( +/*==========================*/ + btr_pcur_t* cursor) /*!< in/out: persistent cursor */ +{ + ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED); + ut_ad(cursor->latch_mode != BTR_NO_LATCHES); + cursor->old_rec = nullptr; + + return page_cur_move_to_prev(btr_pcur_get_page_cur(cursor)); +} + +/*********************************************************//** +Moves the persistent cursor to the next user record in the tree. If no user +records are left, the cursor ends up 'after last in tree'. +@return TRUE if the cursor moved forward, ending on a user record */ +UNIV_INLINE +ibool +btr_pcur_move_to_next_user_rec( +/*===========================*/ + btr_pcur_t* cursor, /*!< in: persistent cursor; NOTE that the + function may release the page latch */ + mtr_t* mtr) /*!< in: mtr */ +{ + ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED); + ut_ad(cursor->latch_mode != BTR_NO_LATCHES); + cursor->old_rec = nullptr; +loop: + if (btr_pcur_is_after_last_on_page(cursor)) { + if (btr_pcur_is_after_last_in_tree(cursor) + || btr_pcur_move_to_next_page(cursor, mtr) != DB_SUCCESS) { + return(FALSE); + } + } else if (UNIV_UNLIKELY(!btr_pcur_move_to_next_on_page(cursor))) { + return false; + } + + if (btr_pcur_is_on_user_rec(cursor)) { + + return(TRUE); + } + + goto loop; +} + +/*********************************************************//** +Moves the persistent cursor to the next record in the tree. If no records are +left, the cursor stays 'after last in tree'. +@return TRUE if the cursor was not after last in tree */ +UNIV_INLINE +ibool +btr_pcur_move_to_next( +/*==================*/ + btr_pcur_t* cursor, /*!< in: persistent cursor; NOTE that the + function may release the page latch */ + mtr_t* mtr) /*!< in: mtr */ +{ + ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED); + ut_ad(cursor->latch_mode != BTR_NO_LATCHES); + + cursor->old_rec= nullptr; + + if (btr_pcur_is_after_last_on_page(cursor)) + return !btr_pcur_is_after_last_in_tree(cursor) && + btr_pcur_move_to_next_page(cursor, mtr) == DB_SUCCESS; + else + return !!btr_pcur_move_to_next_on_page(cursor); +} + +/**************************************************************//** +Commits the mtr and sets the pcur latch mode to BTR_NO_LATCHES, +that is, the cursor becomes detached. +Function btr_pcur_store_position should be used before calling this, +if restoration of cursor is wanted later. */ +UNIV_INLINE +void +btr_pcur_commit_specify_mtr( +/*========================*/ + btr_pcur_t* pcur, /*!< in: persistent cursor */ + mtr_t* mtr) /*!< in: mtr to commit */ +{ + ut_ad(pcur->pos_state == BTR_PCUR_IS_POSITIONED); + + pcur->latch_mode = BTR_NO_LATCHES; + + mtr_commit(mtr); + + pcur->pos_state = BTR_PCUR_WAS_POSITIONED; +} + +/** Commits the mtr and sets the clustered index pcur and secondary index +pcur latch mode to BTR_NO_LATCHES, that is, the cursor becomes detached. +Function btr_pcur_store_position should be used for both cursor before +calling this, if restoration of cursor is wanted later. +@param[in] pcur persistent cursor +@param[in] sec_pcur secondary index persistent cursor +@param[in] mtr mtr to commit */ +UNIV_INLINE +void +btr_pcurs_commit_specify_mtr( + btr_pcur_t* pcur, + btr_pcur_t* sec_pcur, + mtr_t* mtr) +{ + ut_ad(pcur->pos_state == BTR_PCUR_IS_POSITIONED); + ut_ad(sec_pcur->pos_state == BTR_PCUR_IS_POSITIONED); + + pcur->latch_mode = BTR_NO_LATCHES; + sec_pcur->latch_mode = BTR_NO_LATCHES; + + mtr_commit(mtr); + + pcur->pos_state = BTR_PCUR_WAS_POSITIONED; + sec_pcur->pos_state = BTR_PCUR_WAS_POSITIONED; +} + +/**************************************************************//** +Sets the old_rec_buf field to NULL. */ +UNIV_INLINE +void +btr_pcur_init( +/*==========*/ + btr_pcur_t* pcur) /*!< in: persistent cursor */ +{ + pcur->old_rec_buf = NULL; + pcur->old_rec = NULL; + + pcur->btr_cur.rtr_info = NULL; +} + +/** Opens an persistent cursor to an index tree without initializing the +cursor. +@param tuple tuple on which search done +@param mode search mode; NOTE that if the search is made using a + unique prefix of a record, mode should be PAGE_CUR_LE, not + PAGE_CUR_GE, as the latter may end up on the previous page of + the record! +@param latch_mode BTR_SEARCH_LEAF, ... +@param cursor memory buffer for persistent cursor +@param mtr mini-transaction +@return DB_SUCCESS on success or error code otherwise. */ +inline +dberr_t btr_pcur_open_with_no_init(const dtuple_t *tuple, page_cur_mode_t mode, + btr_latch_mode latch_mode, + btr_pcur_t *cursor, mtr_t *mtr) +{ + cursor->latch_mode= BTR_LATCH_MODE_WITHOUT_INTENTION(latch_mode); + cursor->search_mode= mode; + cursor->pos_state= BTR_PCUR_IS_POSITIONED; + cursor->trx_if_known= nullptr; + return cursor->btr_cur.search_leaf(tuple, mode, latch_mode, mtr); +} + +/**************************************************************//** +Frees the possible memory heap of a persistent cursor and sets the latch +mode of the persistent cursor to BTR_NO_LATCHES. +WARNING: this function does not release the latch on the page where the +cursor is currently positioned. The latch is acquired by the +"move to next/previous" family of functions. Since recursive shared locks +are not allowed, you must take care (if using the cursor in S-mode) to +manually release the latch by either calling +btr_leaf_page_release(btr_pcur_get_block(&pcur), pcur.latch_mode, mtr) +or by mtr_t::commit(). */ +UNIV_INLINE +void +btr_pcur_close( +/*===========*/ + btr_pcur_t* cursor) /*!< in: persistent cursor */ +{ + ut_free(cursor->old_rec_buf); + + if (cursor->btr_cur.rtr_info) + rtr_clean_rtr_info(cursor->btr_cur.rtr_info, true); + + cursor->btr_cur.rtr_info= nullptr; + cursor->old_rec = nullptr; + cursor->old_rec_buf = nullptr; + cursor->btr_cur.page_cur.rec = nullptr; + cursor->btr_cur.page_cur.block = nullptr; + + cursor->latch_mode = BTR_NO_LATCHES; + cursor->pos_state = BTR_PCUR_NOT_POSITIONED; + + cursor->trx_if_known = nullptr; +} + +/*********************************************************//** +Moves the persistent cursor to the infimum record on the same page. */ +UNIV_INLINE +void +btr_pcur_move_before_first_on_page( +/*===============================*/ + btr_pcur_t* cursor) /*!< in/out: persistent cursor */ +{ + ut_ad(cursor->latch_mode != BTR_NO_LATCHES); + + page_cur_set_before_first(btr_pcur_get_block(cursor), + btr_pcur_get_page_cur(cursor)); + + cursor->old_rec = nullptr; +} |