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275 lines
7.4 KiB
Text
275 lines
7.4 KiB
Text
/************************************************************************
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The page cursor
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(c) 1994-1996 Innobase Oy
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Created 10/4/1994 Heikki Tuuri
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*************************************************************************/
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#include "page0page.h"
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#include "buf0types.h"
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/*************************************************************
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Gets pointer to the page frame where the cursor is positioned. */
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UNIV_INLINE
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page_t*
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page_cur_get_page(
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/*==============*/
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/* out: page */
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page_cur_t* cur) /* in: page cursor */
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{
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ut_ad(cur);
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return(page_align(cur->rec));
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}
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/*************************************************************
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Gets pointer to the buffer block where the cursor is positioned. */
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UNIV_INLINE
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buf_block_t*
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page_cur_get_block(
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/*===============*/
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/* out: page */
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page_cur_t* cur) /* in: page cursor */
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{
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ut_ad(cur);
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ut_ad(page_align(cur->rec) == cur->block->frame);
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return(cur->block);
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}
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/*************************************************************
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Gets pointer to the page frame where the cursor is positioned. */
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UNIV_INLINE
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page_zip_des_t*
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page_cur_get_page_zip(
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/*==================*/
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/* out: page */
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page_cur_t* cur) /* in: page cursor */
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{
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return(buf_block_get_page_zip(page_cur_get_block(cur)));
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}
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/*************************************************************
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Gets the record where the cursor is positioned. */
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UNIV_INLINE
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rec_t*
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page_cur_get_rec(
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/*=============*/
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/* out: record */
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page_cur_t* cur) /* in: page cursor */
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{
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ut_ad(cur);
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ut_ad(page_align(cur->rec) == cur->block->frame);
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return(cur->rec);
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}
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/*************************************************************
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Sets the cursor object to point before the first user record
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on the page. */
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UNIV_INLINE
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void
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page_cur_set_before_first(
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/*======================*/
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buf_block_t* block, /* in: index page */
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page_cur_t* cur) /* in: cursor */
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{
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cur->rec = page_get_infimum_rec(buf_block_get_frame(block));
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cur->block = block;
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}
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/*************************************************************
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Sets the cursor object to point after the last user record on
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the page. */
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UNIV_INLINE
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void
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page_cur_set_after_last(
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/*====================*/
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buf_block_t* block, /* in: index page */
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page_cur_t* cur) /* in: cursor */
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{
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cur->rec = page_get_supremum_rec(buf_block_get_frame(block));
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cur->block = block;
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}
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/*************************************************************
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Returns TRUE if the cursor is before first user record on page. */
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UNIV_INLINE
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ibool
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page_cur_is_before_first(
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/*=====================*/
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/* out: TRUE if at start */
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const page_cur_t* cur) /* in: cursor */
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{
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return(page_rec_is_infimum(cur->rec));
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}
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/*************************************************************
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Returns TRUE if the cursor is after last user record. */
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UNIV_INLINE
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ibool
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page_cur_is_after_last(
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/*===================*/
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/* out: TRUE if at end */
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const page_cur_t* cur) /* in: cursor */
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{
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return(page_rec_is_supremum(cur->rec));
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}
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/**************************************************************
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Positions the cursor on the given record. */
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UNIV_INLINE
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void
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page_cur_position(
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/*==============*/
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rec_t* rec, /* in: record on a page */
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buf_block_t* block, /* in: buffer block containing the record */
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page_cur_t* cur) /* out: page cursor */
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{
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ut_ad(rec && block && cur);
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ut_ad(page_align(rec) == block->frame);
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cur->rec = rec;
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cur->block = block;
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}
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/**************************************************************
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Invalidates a page cursor by setting the record pointer NULL. */
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UNIV_INLINE
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void
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page_cur_invalidate(
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/*================*/
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page_cur_t* cur) /* in: page cursor */
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{
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ut_ad(cur);
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cur->rec = NULL;
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cur->block = NULL;
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}
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/**************************************************************
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Moves the cursor to the next record on page. */
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UNIV_INLINE
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void
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page_cur_move_to_next(
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/*==================*/
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page_cur_t* cur) /* in: cursor; must not be after last */
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{
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ut_ad(!page_cur_is_after_last(cur));
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cur->rec = page_rec_get_next(cur->rec);
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}
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/**************************************************************
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Moves the cursor to the previous record on page. */
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UNIV_INLINE
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void
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page_cur_move_to_prev(
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/*==================*/
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page_cur_t* cur) /* in: page cursor, not before first */
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{
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ut_ad(!page_cur_is_before_first(cur));
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cur->rec = page_rec_get_prev(cur->rec);
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}
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/********************************************************************
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Searches the right position for a page cursor. */
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UNIV_INLINE
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ulint
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page_cur_search(
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/*============*/
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/* out: number of matched fields on the left */
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buf_block_t* block, /* in: buffer block */
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dict_index_t* index, /* in: record descriptor */
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const dtuple_t* tuple, /* in: data tuple */
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ulint mode, /* in: PAGE_CUR_L, PAGE_CUR_LE, PAGE_CUR_G,
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or PAGE_CUR_GE */
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page_cur_t* cursor) /* out: page cursor */
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{
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ulint low_matched_fields = 0;
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ulint low_matched_bytes = 0;
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ulint up_matched_fields = 0;
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ulint up_matched_bytes = 0;
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ut_ad(dtuple_check_typed(tuple));
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page_cur_search_with_match(block, index, tuple, mode,
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&up_matched_fields,
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&up_matched_bytes,
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&low_matched_fields,
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&low_matched_bytes,
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cursor);
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return(low_matched_fields);
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}
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/***************************************************************
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Inserts a record next to page cursor. Returns pointer to inserted record if
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succeed, i.e., enough space available, NULL otherwise. The cursor stays at
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the same logical position, but the physical position may change if it is
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pointing to a compressed page that was reorganized. */
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UNIV_INLINE
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rec_t*
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page_cur_tuple_insert(
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/*==================*/
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/* out: pointer to record if succeed, NULL
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otherwise */
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page_cur_t* cursor, /* in/out: a page cursor */
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const dtuple_t* tuple, /* in: pointer to a data tuple */
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dict_index_t* index, /* in: record descriptor */
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ulint n_ext, /* in: number of externally stored columns */
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mtr_t* mtr) /* in: mini-transaction handle, or NULL */
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{
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mem_heap_t* heap;
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ulint* offsets;
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ulint size
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= rec_get_converted_size(index, tuple, n_ext);
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rec_t* rec;
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heap = mem_heap_create(size
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+ (4 + REC_OFFS_HEADER_SIZE
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+ dtuple_get_n_fields(tuple))
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* sizeof *offsets);
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rec = rec_convert_dtuple_to_rec((byte*) mem_heap_alloc(heap, size),
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index, tuple, n_ext);
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offsets = rec_get_offsets(rec, index, NULL, ULINT_UNDEFINED, &heap);
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if (buf_block_get_page_zip(cursor->block)) {
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rec = page_cur_insert_rec_zip(&cursor->rec, cursor->block,
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index, rec, offsets, mtr);
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} else {
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rec = page_cur_insert_rec_low(cursor->rec,
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index, rec, offsets, mtr);
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}
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mem_heap_free(heap);
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return(rec);
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}
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/***************************************************************
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Inserts a record next to page cursor. Returns pointer to inserted record if
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succeed, i.e., enough space available, NULL otherwise. The cursor stays at
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the same logical position, but the physical position may change if it is
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pointing to a compressed page that was reorganized. */
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UNIV_INLINE
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rec_t*
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page_cur_rec_insert(
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/*================*/
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/* out: pointer to record if succeed, NULL
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otherwise */
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page_cur_t* cursor, /* in/out: a page cursor */
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const rec_t* rec, /* in: record to insert */
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dict_index_t* index, /* in: record descriptor */
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ulint* offsets,/* in/out: rec_get_offsets(rec, index) */
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mtr_t* mtr) /* in: mini-transaction handle, or NULL */
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{
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if (buf_block_get_page_zip(cursor->block)) {
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return(page_cur_insert_rec_zip(&cursor->rec, cursor->block,
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index, rec, offsets, mtr));
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} else {
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return(page_cur_insert_rec_low(cursor->rec,
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index, rec, offsets, mtr));
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}
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}
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