~drizzle-trunk/drizzle/development

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

Copyright (C) 1994, 2010, Innobase Oy. All Rights Reserved.

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

St, Fifth Floor, Boston, MA 02110-1301 USA

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

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

@file include/btr0cur.h

The index tree cursor

Created 10/16/1994 Heikki Tuuri

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

#ifndef btr0cur_h

#define btr0cur_h

#include "univ.i"

#include "dict0dict.h"

#include "page0cur.h"

#include "btr0types.h"

/* Mode flags for btr_cur operations; these can be ORed */

#define BTR_NO_UNDO_LOG_FLAG	1	/* do no undo logging */

#define BTR_NO_LOCKING_FLAG	2	/* do no record lock checking */

#define BTR_KEEP_SYS_FLAG	4	/* sys fields will be found from the

					update vector or inserted entry */

#ifndef UNIV_HOTBACKUP

#include "que0types.h"

#include "row0types.h"

#include "ha0ha.h"

#define BTR_CUR_ADAPT

#define BTR_CUR_HASH_ADAPT

#ifdef UNIV_DEBUG

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

Returns the page cursor component of a tree cursor.

@return	pointer to page cursor component */

UNIV_INLINE

page_cur_t*

btr_cur_get_page_cur(

/*=================*/

	const btr_cur_t*	cursor);/*!< in: tree cursor */

#else /* UNIV_DEBUG */

# define btr_cur_get_page_cur(cursor) (&(cursor)->page_cur)

#endif /* UNIV_DEBUG */

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

Returns the buffer block on which the tree cursor is positioned.

@return	pointer to buffer block */

UNIV_INLINE

buf_block_t*

btr_cur_get_block(

/*==============*/

	btr_cur_t*	cursor);/*!< in: tree cursor */

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

Returns the record pointer of a tree cursor.

@return	pointer to record */

UNIV_INLINE

rec_t*

btr_cur_get_rec(

/*============*/

	btr_cur_t*	cursor);/*!< in: tree cursor */

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

Returns the compressed page on which the tree cursor is positioned.

@return	pointer to compressed page, or NULL if the page is not compressed */

UNIV_INLINE

page_zip_des_t*

btr_cur_get_page_zip(

/*=================*/

	btr_cur_t*	cursor);/*!< in: tree cursor */

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

Invalidates a tree cursor by setting record pointer to NULL. */

UNIV_INLINE

void

btr_cur_invalidate(

/*===============*/

	btr_cur_t*	cursor);/*!< in: tree cursor */

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

Returns the page of a tree cursor.

@return	pointer to page */

UNIV_INLINE

page_t*

btr_cur_get_page(

/*=============*/

	btr_cur_t*	cursor);/*!< in: tree cursor */

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

Returns the index of a cursor.

@return	index */

UNIV_INLINE

dict_index_t*

btr_cur_get_index(

/*==============*/

	btr_cur_t*	cursor);/*!< in: B-tree cursor */

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

Positions a tree cursor at a given record. */

UNIV_INLINE

void

btr_cur_position(

/*=============*/

	dict_index_t*	index,	/*!< in: index */

	rec_t*		rec,	/*!< in: record in tree */

	buf_block_t*	block,	/*!< in: buffer block of rec */

	btr_cur_t*	cursor);/*!< in: cursor */

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

Searches an index tree and positions a tree cursor on a given level.

NOTE: n_fields_cmp in tuple must be set so that it cannot be compared

to node pointer page number fields on the upper levels of the tree!

Note that if mode is PAGE_CUR_LE, which is used in inserts, then

cursor->up_match and cursor->low_match both will have sensible values.

If mode is PAGE_CUR_GE, then up_match will a have a sensible value. */

UNIV_INTERN

void

btr_cur_search_to_nth_level(

/*========================*/

	dict_index_t*	index,	/*!< in: index */

	ulint		level,	/*!< in: the tree level of search */

	const dtuple_t*	tuple,	/*!< in: data tuple; NOTE: n_fields_cmp in

				tuple must be set so that it cannot get

				compared to the node ptr page number field! */

	ulint		mode,	/*!< in: PAGE_CUR_L, ...;

				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! Inserts

				should always be made using PAGE_CUR_LE to

				search the position! */

	ulint		latch_mode, /*!< in: BTR_SEARCH_LEAF, ..., ORed with

				at most one of BTR_INSERT, BTR_DELETE_MARK,

				BTR_DELETE, or BTR_ESTIMATE;

				cursor->left_block is used to store a pointer

				to the left neighbor page, in the cases

				BTR_SEARCH_PREV and BTR_MODIFY_PREV;

				NOTE that if has_search_latch

				is != 0, we maybe do not have a latch set

				on the cursor page, we assume

				the caller uses his search latch

				to protect the record! */

	btr_cur_t*	cursor, /*!< in/out: tree cursor; the cursor page is

				s- or x-latched, but see also above! */

	ulint		has_search_latch,/*!< in: latch mode the caller

				currently has on btr_search_latch:

				RW_S_LATCH, or 0 */

	const char*	file,	/*!< in: file name */

	ulint		line,	/*!< in: line where called */

	mtr_t*		mtr);	/*!< in: mtr */

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

Opens a cursor at either end of an index. */

UNIV_INTERN

void

btr_cur_open_at_index_side_func(

/*============================*/

	ibool		from_left,	/*!< in: TRUE if open to the low end,

					FALSE if to the high end */

	dict_index_t*	index,		/*!< in: index */

	ulint		latch_mode,	/*!< in: latch mode */

	btr_cur_t*	cursor,		/*!< in: cursor */

	const char*	file,		/*!< in: file name */

	ulint		line,		/*!< in: line where called */

	mtr_t*		mtr);		/*!< in: mtr */

#define btr_cur_open_at_index_side(f,i,l,c,m)				\

	btr_cur_open_at_index_side_func(f,i,l,c,__FILE__,__LINE__,m)

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

Positions a cursor at a randomly chosen position within a B-tree. */

UNIV_INTERN

void

btr_cur_open_at_rnd_pos_func(

/*=========================*/

	dict_index_t*	index,		/*!< in: index */

	ulint		latch_mode,	/*!< in: BTR_SEARCH_LEAF, ... */

	btr_cur_t*	cursor,		/*!< in/out: B-tree cursor */

	const char*	file,		/*!< in: file name */

	ulint		line,		/*!< in: line where called */

	mtr_t*		mtr);		/*!< in: mtr */

#define btr_cur_open_at_rnd_pos(i,l,c,m)				\

	btr_cur_open_at_rnd_pos_func(i,l,c,__FILE__,__LINE__,m)

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

Tries to perform an insert to a page in an index tree, next to cursor.

It is assumed that mtr holds an x-latch on the page. The operation does

not succeed if there is too little space on the page. If there is just

one record on the page, the insert will always succeed; this is to

prevent trying to split a page with just one record.

@return	DB_SUCCESS, DB_WAIT_LOCK, DB_FAIL, or error number */

UNIV_INTERN

ulint

btr_cur_optimistic_insert(

/*======================*/

	ulint		flags,	/*!< in: undo logging and locking flags: if not

				zero, the parameters index and thr should be

				specified */

	btr_cur_t*	cursor,	/*!< in: cursor on page after which to insert;

				cursor stays valid */

	dtuple_t*	entry,	/*!< in/out: entry to insert */

	rec_t**		rec,	/*!< out: pointer to inserted record if

				succeed */

	big_rec_t**	big_rec,/*!< out: big rec vector whose fields have to

				be stored externally by the caller, or

				NULL */

	ulint		n_ext,	/*!< in: number of externally stored columns */

	que_thr_t*	thr,	/*!< in: query thread or NULL */

	mtr_t*		mtr);	/*!< in: mtr; if this function returns

				DB_SUCCESS on a leaf page of a secondary

				index in a compressed tablespace, the

				mtr must be committed before latching

				any further pages */

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

Performs an insert on a page of an index tree. It is assumed that mtr

holds an x-latch on the tree and on the cursor page. If the insert is

made on the leaf level, to avoid deadlocks, mtr must also own x-latches

to brothers of page, if those brothers exist.

@return	DB_SUCCESS or error number */

UNIV_INTERN

ulint

btr_cur_pessimistic_insert(

/*=======================*/

	ulint		flags,	/*!< in: undo logging and locking flags: if not

				zero, the parameter thr should be

				specified; if no undo logging is specified,

				then the caller must have reserved enough

				free extents in the file space so that the

				insertion will certainly succeed */

	btr_cur_t*	cursor,	/*!< in: cursor after which to insert;

				cursor stays valid */

	dtuple_t*	entry,	/*!< in/out: entry to insert */

	rec_t**		rec,	/*!< out: pointer to inserted record if

				succeed */

	big_rec_t**	big_rec,/*!< out: big rec vector whose fields have to

				be stored externally by the caller, or

				NULL */

	ulint		n_ext,	/*!< in: number of externally stored columns */

	que_thr_t*	thr,	/*!< in: query thread or NULL */

	mtr_t*		mtr);	/*!< in: mtr */

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

See if there is enough place in the page modification log to log

an update-in-place.

@return	TRUE if enough place */

UNIV_INTERN

ibool

btr_cur_update_alloc_zip(

/*=====================*/

	page_zip_des_t*	page_zip,/*!< in/out: compressed page */

	buf_block_t*	block,	/*!< in/out: buffer page */

	dict_index_t*	index,	/*!< in: the index corresponding to the block */

	ulint		length,	/*!< in: size needed */

	ibool		create,	/*!< in: TRUE=delete-and-insert,

				FALSE=update-in-place */

	mtr_t*		mtr)	/*!< in: mini-transaction */

	UNIV_WARN_UNUSED_RESULT_NONNULL;

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

Updates a record when the update causes no size changes in its fields.

@return	DB_SUCCESS or error number */

UNIV_INTERN

ulint

btr_cur_update_in_place(

/*====================*/

	ulint		flags,	/*!< in: undo logging and locking flags */

	btr_cur_t*	cursor,	/*!< in: cursor on the record to update;

				cursor stays valid and positioned on the

				same record */

	const upd_t*	update,	/*!< in: update vector */

	ulint		cmpl_info,/*!< in: compiler info on secondary index

				updates */

	que_thr_t*	thr,	/*!< in: query thread */

	mtr_t*		mtr);	/*!< in: mtr; must be committed before

				latching any further pages */

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

Tries to update a record on a page in an index tree. It is assumed that mtr

holds an x-latch on the page. The operation does not succeed if there is too

little space on the page or if the update would result in too empty a page,

so that tree compression is recommended.

@return DB_SUCCESS, or DB_OVERFLOW if the updated record does not fit,

DB_UNDERFLOW if the page would become too empty, or DB_ZIP_OVERFLOW if

there is not enough space left on the compressed page */

UNIV_INTERN

ulint

btr_cur_optimistic_update(

/*======================*/

	ulint		flags,	/*!< in: undo logging and locking flags */

	btr_cur_t*	cursor,	/*!< in: cursor on the record to update;

				cursor stays valid and positioned on the

				same record */

	const upd_t*	update,	/*!< in: update vector; this must also

				contain trx id and roll ptr fields */

	ulint		cmpl_info,/*!< in: compiler info on secondary index

				updates */

	que_thr_t*	thr,	/*!< in: query thread */

	mtr_t*		mtr);	/*!< in: mtr; must be committed before

				latching any further pages */

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

Performs an update of a record on a page of a tree. It is assumed

that mtr holds an x-latch on the tree and on the cursor page. If the

update is made on the leaf level, to avoid deadlocks, mtr must also

own x-latches to brothers of page, if those brothers exist.

@return	DB_SUCCESS or error code */

UNIV_INTERN

ulint

btr_cur_pessimistic_update(

/*=======================*/

	ulint		flags,	/*!< in: undo logging, locking, and rollback

				flags */

	btr_cur_t*	cursor,	/*!< in: cursor on the record to update */

	mem_heap_t**	heap,	/*!< in/out: pointer to memory heap, or NULL */

	big_rec_t**	big_rec,/*!< out: big rec vector whose fields have to

				be stored externally by the caller, or NULL */

	const upd_t*	update,	/*!< in: update vector; this is allowed also

				contain trx id and roll ptr fields, but

				the values in update vector have no effect */

	ulint		cmpl_info,/*!< in: compiler info on secondary index

				updates */

	que_thr_t*	thr,	/*!< in: query thread */

	mtr_t*		mtr);	/*!< in: mtr; must be committed before

				latching any further pages */

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

Marks a clustered index record deleted. Writes an undo log record to

undo log on this delete marking. Writes in the trx id field the id

of the deleting transaction, and in the roll ptr field pointer to the

undo log record created.

@return	DB_SUCCESS, DB_LOCK_WAIT, or error number */

UNIV_INTERN

ulint

btr_cur_del_mark_set_clust_rec(

/*===========================*/

	ulint		flags,	/*!< in: undo logging and locking flags */

	btr_cur_t*	cursor,	/*!< in: cursor */

	ibool		val,	/*!< in: value to set */

	que_thr_t*	thr,	/*!< in: query thread */

	mtr_t*		mtr);	/*!< in: mtr */

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

Sets a secondary index record delete mark to TRUE or FALSE.

@return	DB_SUCCESS, DB_LOCK_WAIT, or error number */

UNIV_INTERN

ulint

btr_cur_del_mark_set_sec_rec(

/*=========================*/

	ulint		flags,	/*!< in: locking flag */

	btr_cur_t*	cursor,	/*!< in: cursor */

	ibool		val,	/*!< in: value to set */

	que_thr_t*	thr,	/*!< in: query thread */

	mtr_t*		mtr);	/*!< in: mtr */

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

Tries to compress a page of the tree if it seems useful. It is assumed

that mtr holds an x-latch on the tree and on the cursor page. To avoid

deadlocks, mtr must also own x-latches to brothers of page, if those

brothers exist. NOTE: it is assumed that the caller has reserved enough

free extents so that the compression will always succeed if done!

@return	TRUE if compression occurred */

UNIV_INTERN

ibool

btr_cur_compress_if_useful(

/*=======================*/

	btr_cur_t*	cursor,	/*!< in: cursor on the page to compress;

				cursor does not stay valid if compression

				occurs */

	mtr_t*		mtr);	/*!< in: mtr */

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

Removes the record on which the tree cursor is positioned. It is assumed

that the mtr has an x-latch on the page where the cursor is positioned,

but no latch on the whole tree.

@return	TRUE if success, i.e., the page did not become too empty */

UNIV_INTERN

ibool

btr_cur_optimistic_delete(

/*======================*/

	btr_cur_t*	cursor,	/*!< in: cursor on the record to delete;

				cursor stays valid: if deletion succeeds,

				on function exit it points to the successor

				of the deleted record */

	mtr_t*		mtr);	/*!< in: mtr; if this function returns

				TRUE on a leaf page of a secondary

				index, the mtr must be committed

				before latching any further pages */

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

Removes the record on which the tree cursor is positioned. Tries

to compress the page if its fillfactor drops below a threshold

or if it is the only page on the level. It is assumed that mtr holds

an x-latch on the tree and on the cursor page. To avoid deadlocks,

mtr must also own x-latches to brothers of page, if those brothers

exist.

@return	TRUE if compression occurred */

UNIV_INTERN

ibool

btr_cur_pessimistic_delete(

/*=======================*/

	ulint*		err,	/*!< out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE;

				the latter may occur because we may have

				to update node pointers on upper levels,

				and in the case of variable length keys

				these may actually grow in size */

	ibool		has_reserved_extents, /*!< in: TRUE if the

				caller has already reserved enough free

				extents so that he knows that the operation

				will succeed */

	btr_cur_t*	cursor,	/*!< in: cursor on the record to delete;

				if compression does not occur, the cursor

				stays valid: it points to successor of

				deleted record on function exit */

	enum trx_rb_ctx	rb_ctx,	/*!< in: rollback context */

	mtr_t*		mtr);	/*!< in: mtr */

#endif /* !UNIV_HOTBACKUP */

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

Parses a redo log record of updating a record in-place.

@return	end of log record or NULL */

UNIV_INTERN

byte*

btr_cur_parse_update_in_place(

/*==========================*/

	byte*		ptr,	/*!< in: buffer */

	byte*		end_ptr,/*!< in: buffer end */

	page_t*		page,	/*!< in/out: page or NULL */

	page_zip_des_t*	page_zip,/*!< in/out: compressed page, or NULL */

	dict_index_t*	index);	/*!< in: index corresponding to page */

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

Parses the redo log record for delete marking or unmarking of a clustered

index record.

@return	end of log record or NULL */

UNIV_INTERN

byte*

btr_cur_parse_del_mark_set_clust_rec(

/*=================================*/

	byte*		ptr,	/*!< in: buffer */

	byte*		end_ptr,/*!< in: buffer end */

	page_t*		page,	/*!< in/out: page or NULL */

	page_zip_des_t*	page_zip,/*!< in/out: compressed page, or NULL */

	dict_index_t*	index);	/*!< in: index corresponding to page */

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

Parses the redo log record for delete marking or unmarking of a secondary

index record.

@return	end of log record or NULL */

UNIV_INTERN

byte*

btr_cur_parse_del_mark_set_sec_rec(

/*===============================*/

	byte*		ptr,	/*!< in: buffer */

	byte*		end_ptr,/*!< in: buffer end */

	page_t*		page,	/*!< in/out: page or NULL */

	page_zip_des_t*	page_zip);/*!< in/out: compressed page, or NULL */

#ifndef UNIV_HOTBACKUP

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

Estimates the number of rows in a given index range.

@return	estimated number of rows */

UNIV_INTERN

ib_int64_t

btr_estimate_n_rows_in_range(

/*=========================*/

	dict_index_t*	index,	/*!< in: index */

	const dtuple_t*	tuple1,	/*!< in: range start, may also be empty tuple */

	ulint		mode1,	/*!< in: search mode for range start */

	const dtuple_t*	tuple2,	/*!< in: range end, may also be empty tuple */

	ulint		mode2);	/*!< in: search mode for range end */

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

Estimates the number of different key values in a given index, for

each n-column prefix of the index where n <= dict_index_get_n_unique(index).

The estimates are stored in the array index->stat_n_diff_key_vals. */

UNIV_INTERN

void

btr_estimate_number_of_different_key_vals(

/*======================================*/

	dict_index_t*	index);	/*!< in: index */

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

Marks not updated extern fields as not-owned by this record. The ownership

is transferred to the updated record which is inserted elsewhere in the

index tree. In purge only the owner of externally stored field is allowed

to free the field.

@return TRUE if BLOB ownership was transferred */

UNIV_INTERN

ibool

btr_cur_mark_extern_inherited_fields(

/*=================================*/

	page_zip_des_t*	page_zip,/*!< in/out: compressed page whose uncompressed

				part will be updated, or NULL */

	rec_t*		rec,	/*!< in/out: record in a clustered index */

	dict_index_t*	index,	/*!< in: index of the page */

	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */

	const upd_t*	update,	/*!< in: update vector */

	mtr_t*		mtr);	/*!< in: mtr, or NULL if not logged */

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

The complement of the previous function: in an update entry may inherit

some externally stored fields from a record. We must mark them as inherited

in entry, so that they are not freed in a rollback. */

UNIV_INTERN

void

btr_cur_mark_dtuple_inherited_extern(

/*=================================*/

	dtuple_t*	entry,		/*!< in/out: updated entry to be

					inserted to clustered index */

	const upd_t*	update);	/*!< in: update vector */

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

Marks all extern fields in a dtuple as owned by the record. */

UNIV_INTERN

void

btr_cur_unmark_dtuple_extern_fields(

/*================================*/

	dtuple_t*	entry);		/*!< in/out: clustered index entry */

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

Stores the fields in big_rec_vec to the tablespace and puts pointers to

them in rec.  The extern flags in rec will have to be set beforehand.

The fields are stored on pages allocated from leaf node

file segment of the index tree.

@return	DB_SUCCESS or DB_OUT_OF_FILE_SPACE */

UNIV_INTERN

ulint

btr_store_big_rec_extern_fields(

/*============================*/

	dict_index_t*	index,		/*!< in: index of rec; the index tree

					MUST be X-latched */

	buf_block_t*	rec_block,	/*!< in/out: block containing rec */

	rec_t*		rec,		/*!< in: record */

	const ulint*	offsets,	/*!< in: rec_get_offsets(rec, index);

					the "external storage" flags in offsets

					will not correspond to rec when

					this function returns */

	big_rec_t*	big_rec_vec,	/*!< in: vector containing fields

					to be stored externally */

	mtr_t*		local_mtr);	/*!< in: mtr containing the latch to

					rec and to the tree */

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

Frees the space in an externally stored field to the file space

management if the field in data is owned the externally stored field,

in a rollback we may have the additional condition that the field must

not be inherited. */

UNIV_INTERN

void

btr_free_externally_stored_field(

/*=============================*/

	dict_index_t*	index,		/*!< in: index of the data, the index

					tree MUST be X-latched; if the tree

					height is 1, then also the root page

					must be X-latched! (this is relevant

					in the case this function is called

					from purge where 'data' is located on

					an undo log page, not an index

					page) */

	byte*		field_ref,	/*!< in/out: field reference */

	const rec_t*	rec,		/*!< in: record containing field_ref, for

					page_zip_write_blob_ptr(), or NULL */

	const ulint*	offsets,	/*!< in: rec_get_offsets(rec, index),

					or NULL */

	page_zip_des_t*	page_zip,	/*!< in: compressed page corresponding

					to rec, or NULL if rec == NULL */

	ulint		i,		/*!< in: field number of field_ref;

					ignored if rec == NULL */

	enum trx_rb_ctx	rb_ctx,		/*!< in: rollback context */

	mtr_t*		local_mtr);	/*!< in: mtr containing the latch to

					data an an X-latch to the index

					tree */

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

Copies the prefix of an externally stored field of a record.  The

clustered index record must be protected by a lock or a page latch.

@return the length of the copied field, or 0 if the column was being

or has been deleted */

UNIV_INTERN

ulint

btr_copy_externally_stored_field_prefix(

/*====================================*/

	byte*		buf,	/*!< out: the field, or a prefix of it */

	ulint		len,	/*!< in: length of buf, in bytes */

	ulint		zip_size,/*!< in: nonzero=compressed BLOB page size,

				zero for uncompressed BLOBs */

	const byte*	data,	/*!< in: 'internally' stored part of the

				field containing also the reference to

				the external part; must be protected by

				a lock or a page latch */

	ulint		local_len);/*!< in: length of data, in bytes */

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

Copies an externally stored field of a record to mem heap.

@return	the field copied to heap, or NULL if the field is incomplete */

UNIV_INTERN

byte*

btr_rec_copy_externally_stored_field(

/*=================================*/

	const rec_t*	rec,	/*!< in: record in a clustered index;

				must be protected by a lock or a page latch */

	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */

	ulint		zip_size,/*!< in: nonzero=compressed BLOB page size,

				zero for uncompressed BLOBs */

	ulint		no,	/*!< in: field number */

	ulint*		len,	/*!< out: length of the field */

	mem_heap_t*	heap);	/*!< in: mem heap */

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

Flags the data tuple fields that are marked as extern storage in the

update vector.  We use this function to remember which fields we must

mark as extern storage in a record inserted for an update.

@return	number of flagged external columns */

UNIV_INTERN

ulint

btr_push_update_extern_fields(

/*==========================*/

	dtuple_t*	tuple,	/*!< in/out: data tuple */

	const upd_t*	update,	/*!< in: update vector */

	mem_heap_t*	heap)	/*!< in: memory heap */

	__attribute__((nonnull));

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

Sets a secondary index record's delete mark to the given value. This

function is only used by the insert buffer merge mechanism. */

UNIV_INTERN

void

btr_cur_set_deleted_flag_for_ibuf(

/*==============================*/

	rec_t*		rec,		/*!< in/out: record */

	page_zip_des_t*	page_zip,	/*!< in/out: compressed page

					corresponding to rec, or NULL

					when the tablespace is

					uncompressed */

	ibool		val,		/*!< in: value to set */

	mtr_t*		mtr);		/*!< in: mtr */

/*######################################################################*/

/** In the pessimistic delete, if the page data size drops below this

limit, merging it to a neighbor is tried */

#define BTR_CUR_PAGE_COMPRESS_LIMIT	(UNIV_PAGE_SIZE / 2)

/** A slot in the path array. We store here info on a search path down the

tree. Each slot contains data on a single level of the tree. */

typedef struct btr_path_struct	btr_path_t;

struct btr_path_struct{

	ulint	nth_rec;	/*!< index of the record

				where the page cursor stopped on

				this level (index in alphabetical

				order); value ULINT_UNDEFINED

				denotes array end */

	ulint	n_recs;		/*!< number of records on the page */

	ulint	page_no;	/*!< no of the page containing the record */

	ulint	page_level;	/*!< level of the page, if later we fetch

				the page under page_no and it is no different

				level then we know that the tree has been

				reorganized */

};

#define BTR_PATH_ARRAY_N_SLOTS	250	/*!< size of path array (in slots) */

/** Values for the flag documenting the used search method */

enum btr_cur_method {

	BTR_CUR_HASH = 1,	/*!< successful shortcut using

				the hash index */

	BTR_CUR_HASH_FAIL,	/*!< failure using hash, success using

				binary search: the misleading hash

				reference is stored in the field

				hash_node, and might be necessary to

				update */

	BTR_CUR_BINARY,		/*!< success using the binary search */

	BTR_CUR_INSERT_TO_IBUF,	/*!< performed the intended insert to

 				the insert buffer */

	BTR_CUR_DEL_MARK_IBUF,	/*!< performed the intended delete

				mark in the insert/delete buffer */

	BTR_CUR_DELETE_IBUF,	/*!< performed the intended delete in

				the insert/delete buffer */

	BTR_CUR_DELETE_REF	/*!< row_purge_poss_sec() failed */

};

/** The tree cursor: the definition appears here only for the compiler

to know struct size! */

struct btr_cur_struct {

	dict_index_t*	index;		/*!< index where positioned */

	page_cur_t	page_cur;	/*!< page cursor */

	purge_node_t*	purge_node;	/*!< purge node, for BTR_DELETE */

	buf_block_t*	left_block;	/*!< this field is used to store

					a pointer to the left neighbor

					page, in the cases

					BTR_SEARCH_PREV and

					BTR_MODIFY_PREV */

	/*------------------------------*/

	que_thr_t*	thr;		/*!< this field is only used

					when btr_cur_search_to_nth_level

					is called for an index entry

					insertion: the calling query

					thread is passed here to be

					used in the insert buffer */

	/*------------------------------*/

	/** The following fields are used in

	btr_cur_search_to_nth_level to pass information: */

	/* @{ */

	enum btr_cur_method	flag;	/*!< Search method used */

	ulint		tree_height;	/*!< Tree height if the search is done

					for a pessimistic insert or update

					operation */

	ulint		up_match;	/*!< If the search mode was PAGE_CUR_LE,

					the number of matched fields to the

					the first user record to the right of

					the cursor record after

					btr_cur_search_to_nth_level;

					for the mode PAGE_CUR_GE, the matched

					fields to the first user record AT THE

					CURSOR or to the right of it;

					NOTE that the up_match and low_match

					values may exceed the correct values

					for comparison to the adjacent user

					record if that record is on a

					different leaf page! (See the note in

					row_ins_duplicate_key.) */

	ulint		up_bytes;	/*!< number of matched bytes to the

					right at the time cursor positioned;

					only used internally in searches: not

					defined after the search */

	ulint		low_match;	/*!< if search mode was PAGE_CUR_LE,

					the number of matched fields to the

					first user record AT THE CURSOR or

					to the left of it after

					btr_cur_search_to_nth_level;

					NOT defined for PAGE_CUR_GE or any

					other search modes; see also the NOTE

					in up_match! */

	ulint		low_bytes;	/*!< number of matched bytes to the

					right at the time cursor positioned;

					only used internally in searches: not

					defined after the search */

	ulint		n_fields;	/*!< prefix length used in a hash

					search if hash_node != NULL */

	ulint		n_bytes;	/*!< hash prefix bytes if hash_node !=

					NULL */

	ulint		fold;		/*!< fold value used in the search if

					flag is BTR_CUR_HASH */

	/*----- Delete buffering -------*/

	ulint		ibuf_cnt;	/* in searches done on insert buffer

					trees, this contains the "counter"

					value (the first two bytes of the

					fourth field) extracted from the

					page above the leaf page, from the

					father node pointer that pointed to

					the leaf page. in other words, it

					contains the minimum counter value

					for records to be inserted on the

					chosen leaf page. If for some reason

					this can't be read, or if the search

					ended on the leftmost leaf page in

					the tree (in which case the father

					node pointer had the 'minimum

					record' flag set), this is

					ULINT_UNDEFINED. */

	/*------------------------------*/

	/* @} */

	btr_path_t*	path_arr;	/*!< in estimating the number of

					rows in range, we store in this array

					information of the path through

					the tree */

};

/** If pessimistic delete fails because of lack of file space, there

is still a good change of success a little later.  Try this many

times. */

#define BTR_CUR_RETRY_DELETE_N_TIMES	100

/** If pessimistic delete fails because of lack of file space, there

is still a good change of success a little later.  Sleep this many

microseconds between retries. */

#define BTR_CUR_RETRY_SLEEP_TIME	50000

/** The reference in a field for which data is stored on a different page.

The reference is at the end of the 'locally' stored part of the field.

'Locally' means storage in the index record.

We store locally a long enough prefix of each column so that we can determine

the ordering parts of each index record without looking into the externally

stored part. */

/*-------------------------------------- @{ */

#define BTR_EXTERN_SPACE_ID		0	/*!< space id where stored */

#define BTR_EXTERN_PAGE_NO		4	/*!< page no where stored */

#define BTR_EXTERN_OFFSET		8	/*!< offset of BLOB header

						on that page */

#define BTR_EXTERN_LEN			12	/*!< 8 bytes containing the

						length of the externally

						stored part of the BLOB.

						The 2 highest bits are

						reserved to the flags below. */

/*-------------------------------------- @} */

/* #define BTR_EXTERN_FIELD_REF_SIZE	20 // moved to btr0types.h */

/** The most significant bit of BTR_EXTERN_LEN (i.e., the most

significant bit of the byte at smallest address) is set to 1 if this

field does not 'own' the externally stored field; only the owner field

is allowed to free the field in purge! */

#define BTR_EXTERN_OWNER_FLAG		128

/** If the second most significant bit of BTR_EXTERN_LEN (i.e., the

second most significant bit of the byte at smallest address) is 1 then

it means that the externally stored field was inherited from an

earlier version of the row.  In rollback we are not allowed to free an

inherited external field. */

#define BTR_EXTERN_INHERITED_FLAG	64

/** Number of searches down the B-tree in btr_cur_search_to_nth_level(). */

extern ulint	btr_cur_n_non_sea;

/** Number of successful adaptive hash index lookups in

btr_cur_search_to_nth_level(). */

extern ulint	btr_cur_n_sea;

/** Old value of btr_cur_n_non_sea.  Copied by

srv_refresh_innodb_monitor_stats().  Referenced by

srv_printf_innodb_monitor(). */

extern ulint	btr_cur_n_non_sea_old;

/** Old value of btr_cur_n_sea.  Copied by

srv_refresh_innodb_monitor_stats().  Referenced by

srv_printf_innodb_monitor(). */

extern ulint	btr_cur_n_sea_old;

#endif /* !UNIV_HOTBACKUP */

#ifndef UNIV_NONINL

#include "btr0cur.ic"

#endif

#endif