/*****************************************************************************

Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2018, 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/page0cur.h
The page cursor

Created 10/4/1994 Heikki Tuuri
*************************************************************************/

#ifndef page0cur_h
#define page0cur_h

#include "buf0types.h"
#include "page0page.h"
#include "rem0types.h"
#include "rem0rec.h"
#include "data0data.h"
#include "mtr0mtr.h"
#include "gis0type.h"

#ifdef UNIV_DEBUG
/*********************************************************//**
Gets pointer to the page frame where the cursor is positioned.
@return page */
UNIV_INLINE
page_t*
page_cur_get_page(
/*==============*/
	page_cur_t*	cur);	/*!< in: page cursor */
/*********************************************************//**
Gets pointer to the buffer block where the cursor is positioned.
@return page */
UNIV_INLINE
buf_block_t*
page_cur_get_block(
/*===============*/
	page_cur_t*	cur);	/*!< in: page cursor */
/*********************************************************//**
Gets pointer to the page frame where the cursor is positioned.
@return page */
UNIV_INLINE
page_zip_des_t*
page_cur_get_page_zip(
/*==================*/
	page_cur_t*	cur);	/*!< in: page cursor */
/*********************************************************//**
Gets the record where the cursor is positioned.
@return record */
UNIV_INLINE
rec_t*
page_cur_get_rec(
/*=============*/
	page_cur_t*	cur);	/*!< in: page cursor */
#else /* UNIV_DEBUG */
# define page_cur_get_page(cur)		page_align((cur)->rec)
# define page_cur_get_block(cur)	(cur)->block
# define page_cur_get_page_zip(cur)	buf_block_get_page_zip((cur)->block)
# define page_cur_get_rec(cur)		(cur)->rec
#endif /* UNIV_DEBUG */
/*********************************************************//**
Sets the cursor object to point before the first user record
on the page. */
UNIV_INLINE
void
page_cur_set_before_first(
/*======================*/
	const buf_block_t*	block,	/*!< in: index page */
	page_cur_t*		cur);	/*!< in: cursor */
/*********************************************************//**
Sets the cursor object to point after the last user record on
the page. */
UNIV_INLINE
void
page_cur_set_after_last(
/*====================*/
	const buf_block_t*	block,	/*!< in: index page */
	page_cur_t*		cur);	/*!< in: cursor */
/*********************************************************//**
Returns TRUE if the cursor is before first user record on page.
@return TRUE if at start */
UNIV_INLINE
ibool
page_cur_is_before_first(
/*=====================*/
	const page_cur_t*	cur);	/*!< in: cursor */
/*********************************************************//**
Returns TRUE if the cursor is after last user record.
@return TRUE if at end */
UNIV_INLINE
ibool
page_cur_is_after_last(
/*===================*/
	const page_cur_t*	cur);	/*!< in: cursor */
/**********************************************************//**
Positions the cursor on the given record. */
UNIV_INLINE
void
page_cur_position(
/*==============*/
	const rec_t*		rec,	/*!< in: record on a page */
	const buf_block_t*	block,	/*!< in: buffer block containing
					the record */
	page_cur_t*		cur);	/*!< out: page cursor */
/**********************************************************//**
Moves the cursor to the next record on page. */
UNIV_INLINE
void
page_cur_move_to_next(
/*==================*/
	page_cur_t*	cur);	/*!< in/out: cursor; must not be after last */
/**********************************************************//**
Moves the cursor to the previous record on page. */
UNIV_INLINE
void
page_cur_move_to_prev(
/*==================*/
	page_cur_t*	cur);	/*!< in/out: cursor; not before first */

/***********************************************************//**
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 logical position, but the physical position may change if it is
pointing to a compressed page that was reorganized.

IMPORTANT: The caller will have to update IBUF_BITMAP_FREE
if this is a compressed leaf page in a secondary index.
This has to be done either within the same mini-transaction,
or by invoking ibuf_reset_free_bits() before mtr_commit().

@return pointer to record if succeed, NULL otherwise */
UNIV_INLINE
rec_t*
page_cur_tuple_insert(
/*==================*/
	page_cur_t*	cursor,	/*!< in/out: a page cursor */
	const dtuple_t*	tuple,	/*!< in: pointer to a data tuple */
	dict_index_t*	index,	/*!< in: record descriptor */
	rec_offs**	offsets,/*!< out: offsets on *rec */
	mem_heap_t**	heap,	/*!< in/out: pointer to memory heap, or NULL */
	ulint		n_ext,	/*!< in: number of externally stored columns */
	mtr_t*		mtr)	/*!< in: mini-transaction handle, or NULL */
	MY_ATTRIBUTE((nonnull(1,2,3,4,5), warn_unused_result));
/***********************************************************//**
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 logical position, but the physical position may change if it is
pointing to a compressed page that was reorganized.

IMPORTANT: The caller will have to update IBUF_BITMAP_FREE
if this is a compressed leaf page in a secondary index.
This has to be done either within the same mini-transaction,
or by invoking ibuf_reset_free_bits() before mtr_commit().

@return pointer to record if succeed, NULL otherwise */
UNIV_INLINE
rec_t*
page_cur_rec_insert(
/*================*/
	page_cur_t*	cursor,	/*!< in/out: a page cursor */
	const rec_t*	rec,	/*!< in: record to insert */
	dict_index_t*	index,	/*!< in: record descriptor */
	rec_offs*	offsets,/*!< in/out: rec_get_offsets(rec, index) */
	mtr_t*		mtr);	/*!< in: mini-transaction handle, or NULL */
/***********************************************************//**
Inserts a record next to page cursor on an uncompressed page.
Returns pointer to inserted record if succeed, i.e., enough
space available, NULL otherwise. The cursor stays at the same position.
@return pointer to record if succeed, NULL otherwise */
rec_t*
page_cur_insert_rec_low(
/*====================*/
	rec_t*		current_rec,/*!< in: pointer to current record after
				which the new record is inserted */
	dict_index_t*	index,	/*!< in: record descriptor */
	const rec_t*	rec,	/*!< in: pointer to a physical record */
	rec_offs*	offsets,/*!< in/out: rec_get_offsets(rec, index) */
	mtr_t*		mtr)	/*!< in: mini-transaction handle, or NULL */
	MY_ATTRIBUTE((nonnull(1,2,3,4), warn_unused_result));

/***********************************************************//**
Inserts a record next to page cursor on a compressed and uncompressed
page. Returns pointer to inserted record if succeed, i.e.,
enough space available, NULL otherwise.
The cursor stays at the same position.

IMPORTANT: The caller will have to update IBUF_BITMAP_FREE
if this is a compressed leaf page in a secondary index.
This has to be done either within the same mini-transaction,
or by invoking ibuf_reset_free_bits() before mtr_commit().

@return pointer to record if succeed, NULL otherwise */
rec_t*
page_cur_insert_rec_zip(
/*====================*/
	page_cur_t*	cursor,	/*!< in/out: page cursor */
	dict_index_t*	index,	/*!< in: record descriptor */
	const rec_t*	rec,	/*!< in: pointer to a physical record */
	rec_offs*	offsets,/*!< in/out: rec_get_offsets(rec, index) */
	mtr_t*		mtr)	/*!< in: mini-transaction handle, or NULL */
	MY_ATTRIBUTE((nonnull(1,2,3,4), warn_unused_result));
/*************************************************************//**
Copies records from page to a newly created page, from a given record onward,
including that record. Infimum and supremum records are not copied.

IMPORTANT: The caller will have to update IBUF_BITMAP_FREE
if this is a compressed leaf page in a secondary index.
This has to be done either within the same mini-transaction,
or by invoking ibuf_reset_free_bits() before mtr_commit(). */
void
page_copy_rec_list_end_to_created_page(
/*===================================*/
	page_t*		new_page,	/*!< in/out: index page to copy to */
	rec_t*		rec,		/*!< in: first record to copy */
	dict_index_t*	index,		/*!< in: record descriptor */
	mtr_t*		mtr);		/*!< in: mtr */
/***********************************************************//**
Deletes a record at the page cursor. The cursor is moved to the
next record after the deleted one. */
void
page_cur_delete_rec(
/*================*/
	page_cur_t*		cursor,	/*!< in/out: a page cursor */
	const dict_index_t*	index,	/*!< in: record descriptor */
	const rec_offs*		offsets,/*!< in: rec_get_offsets(
					cursor->rec, index) */
	mtr_t*			mtr);	/*!< in: mini-transaction handle */

/** Search the right position for a page cursor.
@param[in] block buffer block
@param[in] index index tree
@param[in] tuple data tuple
@param[in] mode PAGE_CUR_L, PAGE_CUR_LE, PAGE_CUR_G, or PAGE_CUR_GE
@param[out] cursor page cursor
@return number of matched fields on the left */
UNIV_INLINE
ulint
page_cur_search(
	const buf_block_t*	block,
	const dict_index_t*	index,
	const dtuple_t*		tuple,
	page_cur_mode_t		mode,
	page_cur_t*		cursor);

/** Search the right position for a page cursor.
@param[in] block buffer block
@param[in] index index tree
@param[in] tuple data tuple
@param[out] cursor page cursor
@return number of matched fields on the left */
UNIV_INLINE
ulint
page_cur_search(
	const buf_block_t*	block,
	const dict_index_t*	index,
	const dtuple_t*		tuple,
	page_cur_t*		cursor);

/****************************************************************//**
Searches the right position for a page cursor. */
void
page_cur_search_with_match(
/*=======================*/
	const buf_block_t*	block,	/*!< in: buffer block */
	const dict_index_t*	index,	/*!< in: record descriptor */
	const dtuple_t*		tuple,	/*!< in: data tuple */
	page_cur_mode_t		mode,	/*!< in: PAGE_CUR_L,
					PAGE_CUR_LE, PAGE_CUR_G, or
					PAGE_CUR_GE */
	ulint*			iup_matched_fields,
					/*!< in/out: already matched
					fields in upper limit record */
	ulint*			ilow_matched_fields,
					/*!< in/out: already matched
					fields in lower limit record */
	page_cur_t*		cursor,	/*!< out: page cursor */
	rtr_info_t*		rtr_info);/*!< in/out: rtree search stack */
#ifdef BTR_CUR_HASH_ADAPT
/** Search the right position for a page cursor.
@param[in]	block			buffer block
@param[in]	index			index tree
@param[in]	tuple			key to be searched for
@param[in]	mode			search mode
@param[in,out]	iup_matched_fields	already matched fields in the
upper limit record
@param[in,out]	iup_matched_bytes	already matched bytes in the
first partially matched field in the upper limit record
@param[in,out]	ilow_matched_fields	already matched fields in the
lower limit record
@param[in,out]	ilow_matched_bytes	already matched bytes in the
first partially matched field in the lower limit record
@param[out]	cursor			page cursor */
void
page_cur_search_with_match_bytes(
	const buf_block_t*	block,
	const dict_index_t*	index,
	const dtuple_t*		tuple,
	page_cur_mode_t		mode,
	ulint*			iup_matched_fields,
	ulint*			iup_matched_bytes,
	ulint*			ilow_matched_fields,
	ulint*			ilow_matched_bytes,
	page_cur_t*		cursor);
#endif /* BTR_CUR_HASH_ADAPT */
/***********************************************************//**
Positions a page cursor on a randomly chosen user record on a page. If there
are no user records, sets the cursor on the infimum record. */
void
page_cur_open_on_rnd_user_rec(
/*==========================*/
	buf_block_t*	block,	/*!< in: page */
	page_cur_t*	cursor);/*!< out: page cursor */
/** Write a redo log record of inserting a record into an index page.
@param[in]	insert_rec	inserted record
@param[in]	rec_size	rec_get_size(insert_rec)
@param[in]	cursor_rec	predecessor of insert_rec
@param[in,out]	index		index tree
@param[in,out]	mtr		mini-transaction */
void
page_cur_insert_rec_write_log(
	const rec_t*	insert_rec,
	ulint		rec_size,
	const rec_t*	cursor_rec,
	dict_index_t*	index,
	mtr_t*		mtr)
	MY_ATTRIBUTE((nonnull));
/***********************************************************//**
Parses a log record of a record insert on a page.
@return end of log record or NULL */
byte*
page_cur_parse_insert_rec(
/*======================*/
	ibool		is_short,/*!< in: TRUE if short inserts */
	const byte*	ptr,	/*!< in: buffer */
	const byte*	end_ptr,/*!< in: buffer end */
	buf_block_t*	block,	/*!< in: page or NULL */
	dict_index_t*	index,	/*!< in: record descriptor */
	mtr_t*		mtr);	/*!< in: mtr or NULL */
/**********************************************************//**
Parses a log record of copying a record list end to a new created page.
@return end of log record or NULL */
byte*
page_parse_copy_rec_list_to_created_page(
/*=====================================*/
	byte*		ptr,	/*!< in: buffer */
	byte*		end_ptr,/*!< in: buffer end */
	buf_block_t*	block,	/*!< in: page or NULL */
	dict_index_t*	index,	/*!< in: record descriptor */
	mtr_t*		mtr);	/*!< in: mtr or NULL */
/***********************************************************//**
Parses log record of a record delete on a page.
@return pointer to record end or NULL */
byte*
page_cur_parse_delete_rec(
/*======================*/
	byte*		ptr,	/*!< in: buffer */
	byte*		end_ptr,/*!< in: buffer end */
	buf_block_t*	block,	/*!< in: page or NULL */
	dict_index_t*	index,	/*!< in: record descriptor */
	mtr_t*		mtr);	/*!< in: mtr or NULL */
/*******************************************************//**
Removes the record from a leaf page. This function does not log
any changes. It is used by the IMPORT tablespace functions.
@return true if success, i.e., the page did not become too empty */
bool
page_delete_rec(
/*============*/
	const dict_index_t*	index,	/*!< in: The index that the record
					belongs to */
	page_cur_t*		pcur,	/*!< in/out: page cursor on record
					to delete */
	page_zip_des_t*		page_zip,/*!< in: compressed page descriptor */
	const rec_offs*		offsets);/*!< in: offsets for record */

/** Index page cursor */

struct page_cur_t{
	const dict_index_t*	index;
	rec_t*		rec;	/*!< pointer to a record on page */
	rec_offs*	offsets;
	buf_block_t*	block;	/*!< pointer to the block containing rec */
};

#include "page0cur.inl"

#endif