btr0btr.ic
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上传日期:2022-05-23
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文件大小:6k
- /******************************************************
- The B-tree
- (c) 1994-1996 Innobase Oy
- Created 6/2/1994 Heikki Tuuri
- *******************************************************/
- #include "mach0data.h"
- #include "mtr0mtr.h"
- #include "mtr0log.h"
- #define BTR_MAX_NODE_LEVEL 50 /* used in debug checking */
- /******************************************************************
- Gets a buffer page and declares its latching order level. */
- UNIV_INLINE
- page_t*
- btr_page_get(
- /*=========*/
- ulint space, /* in: space id */
- ulint page_no, /* in: page number */
- ulint mode, /* in: latch mode */
- mtr_t* mtr) /* in: mtr */
- {
- page_t* page;
- page = buf_page_get(space, page_no, mode, mtr);
- #ifdef UNIV_SYNC_DEBUG
- if (mode != RW_NO_LATCH) {
-
- buf_page_dbg_add_level(page, SYNC_TREE_NODE);
- }
- #endif
- return(page);
- }
- /******************************************************************
- Sets the index id field of a page. */
- UNIV_INLINE
- void
- btr_page_set_index_id(
- /*==================*/
- page_t* page, /* in: page to be created */
- dulint id, /* in: index id */
- mtr_t* mtr) /* in: mtr */
- {
- mlog_write_dulint(page + PAGE_HEADER + PAGE_INDEX_ID, id, mtr);
- }
- /******************************************************************
- Gets the index id field of a page. */
- UNIV_INLINE
- dulint
- btr_page_get_index_id(
- /*==================*/
- /* out: index id */
- page_t* page) /* in: index page */
- {
- return(mach_read_from_8(page + PAGE_HEADER + PAGE_INDEX_ID));
- }
- /************************************************************
- Gets the node level field in an index page. */
- UNIV_INLINE
- ulint
- btr_page_get_level_low(
- /*===================*/
- /* out: level, leaf level == 0 */
- page_t* page) /* in: index page */
- {
- ulint level;
- ut_ad(page);
-
- level = mach_read_from_2(page + PAGE_HEADER + PAGE_LEVEL);
- ut_ad(level <= BTR_MAX_NODE_LEVEL);
- return(level);
- }
- /************************************************************
- Gets the node level field in an index page. */
- UNIV_INLINE
- ulint
- btr_page_get_level(
- /*===============*/
- /* out: level, leaf level == 0 */
- page_t* page, /* in: index page */
- mtr_t* mtr __attribute__((unused))) /* in: mini-transaction handle */
- {
- ut_ad(page && mtr);
- return(btr_page_get_level_low(page));
- }
- /************************************************************
- Sets the node level field in an index page. */
- UNIV_INLINE
- void
- btr_page_set_level(
- /*===============*/
- page_t* page, /* in: index page */
- ulint level, /* in: level, leaf level == 0 */
- mtr_t* mtr) /* in: mini-transaction handle */
- {
- ut_ad(page && mtr);
- ut_ad(level <= BTR_MAX_NODE_LEVEL);
- mlog_write_ulint(page + PAGE_HEADER + PAGE_LEVEL, level,
- MLOG_2BYTES, mtr);
- }
- /************************************************************
- Gets the next index page number. */
- UNIV_INLINE
- ulint
- btr_page_get_next(
- /*==============*/
- /* out: next page number */
- page_t* page, /* in: index page */
- mtr_t* mtr __attribute__((unused))) /* in: mini-transaction handle */
- {
- ut_ad(page && mtr);
- ut_ad(mtr_memo_contains(mtr, buf_block_align(page),
- MTR_MEMO_PAGE_X_FIX)
- || mtr_memo_contains(mtr, buf_block_align(page),
- MTR_MEMO_PAGE_S_FIX));
- return(mach_read_from_4(page + FIL_PAGE_NEXT));
- }
- /************************************************************
- Sets the next index page field. */
- UNIV_INLINE
- void
- btr_page_set_next(
- /*==============*/
- page_t* page, /* in: index page */
- ulint next, /* in: next page number */
- mtr_t* mtr) /* in: mini-transaction handle */
- {
- ut_ad(page && mtr);
- mlog_write_ulint(page + FIL_PAGE_NEXT, next, MLOG_4BYTES, mtr);
- }
- /************************************************************
- Gets the previous index page number. */
- UNIV_INLINE
- ulint
- btr_page_get_prev(
- /*==============*/
- /* out: prev page number */
- page_t* page, /* in: index page */
- mtr_t* mtr __attribute__((unused))) /* in: mini-transaction handle */
- {
- ut_ad(page && mtr);
-
- return(mach_read_from_4(page + FIL_PAGE_PREV));
- }
- /************************************************************
- Sets the previous index page field. */
- UNIV_INLINE
- void
- btr_page_set_prev(
- /*==============*/
- page_t* page, /* in: index page */
- ulint prev, /* in: previous page number */
- mtr_t* mtr) /* in: mini-transaction handle */
- {
- ut_ad(page && mtr);
- mlog_write_ulint(page + FIL_PAGE_PREV, prev, MLOG_4BYTES, mtr);
- }
- /******************************************************************
- Gets the child node file address in a node pointer. */
- UNIV_INLINE
- ulint
- btr_node_ptr_get_child_page_no(
- /*===========================*/
- /* out: child node address */
- rec_t* rec) /* in: node pointer record */
- {
- ulint n_fields;
- byte* field;
- ulint len;
- ulint page_no;
- n_fields = rec_get_n_fields(rec);
- /* The child address is in the last field */
- field = rec_get_nth_field(rec, n_fields - 1, &len);
- ut_ad(len == 4);
-
- page_no = mach_read_from_4(field);
- if (page_no == 0) {
- fprintf(stderr,
- "InnoDB: a nonsensical page number 0 in a node ptr record at offset %lun",
- (unsigned long)(rec - buf_frame_align(rec)));
- buf_page_print(buf_frame_align(rec));
- }
- return(page_no);
- }
- /******************************************************************
- Releases the latches on a leaf page and bufferunfixes it. */
- UNIV_INLINE
- void
- btr_leaf_page_release(
- /*==================*/
- page_t* page, /* in: page */
- ulint latch_mode, /* in: BTR_SEARCH_LEAF or BTR_MODIFY_LEAF */
- mtr_t* mtr) /* in: mtr */
- {
- ut_ad(!mtr_memo_contains(mtr, buf_block_align(page),
- MTR_MEMO_MODIFY));
- if (latch_mode == BTR_SEARCH_LEAF) {
- mtr_memo_release(mtr, buf_block_align(page),
- MTR_MEMO_PAGE_S_FIX);
- } else {
- ut_ad(latch_mode == BTR_MODIFY_LEAF);
- mtr_memo_release(mtr, buf_block_align(page),
- MTR_MEMO_PAGE_X_FIX);
- }
- }