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/************************************************************************
The page cursor
(c) 1994-1996 Innobase Oy
Created 10/4/1994 Heikki Tuuri
*************************************************************************/
#include "page0page.h"
/*************************************************************
Gets pointer to the page frame where the cursor is positioned. */
UNIV_INLINE
page_t*
page_cur_get_page(
/*==============*/
/* out: page */
page_cur_t* cur) /* in: page cursor */
{
ut_ad(cur);
return(buf_frame_align(cur->rec));
}
/*************************************************************
Gets the record where the cursor is positioned. */
UNIV_INLINE
rec_t*
page_cur_get_rec(
/*=============*/
/* out: record */
page_cur_t* cur) /* in: page cursor */
{
ut_ad(cur);
return(cur->rec);
}
/*************************************************************
Sets the cursor object to point before the first user record
on the page. */
UNIV_INLINE
void
page_cur_set_before_first(
/*======================*/
page_t* page, /* in: index page */
page_cur_t* cur) /* in: cursor */
{
cur->rec = page_get_infimum_rec(page);
}
/*************************************************************
Sets the cursor object to point after the last user record on
the page. */
UNIV_INLINE
void
page_cur_set_after_last(
/*====================*/
page_t* page, /* in: index page */
page_cur_t* cur) /* in: cursor */
{
cur->rec = page_get_supremum_rec(page);
}
/*************************************************************
Returns TRUE if the cursor is before first user record on page. */
UNIV_INLINE
ibool
page_cur_is_before_first(
/*=====================*/
/* out: TRUE if at start */
const page_cur_t* cur) /* in: cursor */
{
return(page_rec_is_infimum(cur->rec));
}
/*************************************************************
Returns TRUE if the cursor is after last user record. */
UNIV_INLINE
ibool
page_cur_is_after_last(
/*===================*/
/* out: TRUE if at end */
const page_cur_t* cur) /* in: cursor */
{
return(page_rec_is_supremum(cur->rec));
}
/**************************************************************
Positions the cursor on the given record. */
UNIV_INLINE
void
page_cur_position(
/*==============*/
rec_t* rec, /* in: record on a page */
page_cur_t* cur) /* in: page cursor */
{
ut_ad(rec && cur);
cur->rec = rec;
}
/**************************************************************
Invalidates a page cursor by setting the record pointer NULL. */
UNIV_INLINE
void
page_cur_invalidate(
/*================*/
page_cur_t* cur) /* in: page cursor */
{
ut_ad(cur);
cur->rec = NULL;
}
/**************************************************************
Moves the cursor to the next record on page. */
UNIV_INLINE
void
page_cur_move_to_next(
/*==================*/
page_cur_t* cur) /* in: cursor; must not be after last */
{
ut_ad(!page_cur_is_after_last(cur));
cur->rec = page_rec_get_next(cur->rec);
}
/**************************************************************
Moves the cursor to the previous record on page. */
UNIV_INLINE
void
page_cur_move_to_prev(
/*==================*/
page_cur_t* cur) /* in: page cursor, not before first */
{
ut_ad(!page_cur_is_before_first(cur));
cur->rec = page_rec_get_prev(cur->rec);
}
/********************************************************************
Searches the right position for a page cursor. */
UNIV_INLINE
ulint
page_cur_search(
/*============*/
/* out: number of matched fields on the left */
page_t* page, /* in: index page */
dict_index_t* index, /* in: record descriptor */
dtuple_t* tuple, /* in: data tuple */
ulint mode, /* in: PAGE_CUR_L, PAGE_CUR_LE, PAGE_CUR_G,
or PAGE_CUR_GE */
page_cur_t* cursor) /* out: page cursor */
{
ulint low_matched_fields = 0;
ulint low_matched_bytes = 0;
ulint up_matched_fields = 0;
ulint up_matched_bytes = 0;
ut_ad(dtuple_check_typed(tuple));
page_cur_search_with_match(page, index, tuple, mode,
&up_matched_fields,
&up_matched_bytes,
&low_matched_fields,
&low_matched_bytes,
cursor);
return(low_matched_fields);
}
/***************************************************************
Inserts a record next to page cursor. Returns pointer to inserted record if
succeed, i.e., enough space available, NULL otherwise. The cursor stays at
the same position. */
UNIV_INLINE
rec_t*
page_cur_tuple_insert(
/*==================*/
/* out: pointer to record if succeed, NULL
otherwise */
page_cur_t* cursor, /* in: a page cursor */
dtuple_t* tuple, /* in: pointer to a data tuple */
dict_index_t* index, /* in: record descriptor */
mtr_t* mtr) /* in: mini-transaction handle */
{
return(page_cur_insert_rec_low(cursor, tuple, index, NULL, NULL, mtr));
}
/***************************************************************
Inserts a record next to page cursor. Returns pointer to inserted record if
succeed, i.e., enough space available, NULL otherwise. The cursor stays at
the same position. */
UNIV_INLINE
rec_t*
page_cur_rec_insert(
/*================*/
/* out: pointer to record if succeed, NULL
otherwise */
page_cur_t* cursor, /* in: a page cursor */
rec_t* rec, /* in: record to insert */
dict_index_t* index, /* in: record descriptor */
ulint* offsets,/* in: rec_get_offsets(rec, index) */
mtr_t* mtr) /* in: mini-transaction handle */
{
return(page_cur_insert_rec_low(cursor, NULL, index, rec,
offsets, mtr));
}
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