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mariadb/storage/innodb_plugin/include/btr0cur.h
Marko Mäkelä f77329ace9 Bug#13721257 RACE CONDITION IN UPDATES OR INSERTS OF WIDE RECORDS 
This bug was originally filed and fixed as Bug#12612184. The original
fix was buggy, and it was patched by Bug#12704861. Also that patch was
buggy (potentially breaking crash recovery), and both fixes were
reverted.

This fix was not ported to the built-in InnoDB of MySQL 5.1, because
the function signatures of many core functions are different from
InnoDB Plugin and later versions. The block allocation routines and
their callers would have to changed so that they handle block
descriptors instead of page frames.

When a record is updated so that its size grows, non-updated columns
can be selected for external (off-page) storage. The bug is that the
initially inserted updated record contains an all-zero BLOB pointer to
the field that was not updated. Only after the BLOB pages have been
allocated and written, the valid pointer can be written to the record.

Between the release of the page latch in mtr_commit(mtr) after
btr_cur_pessimistic_update() and the re-latching of the page in
btr_pcur_restore_position(), other threads can see the invalid BLOB
pointer consisting of 20 zero bytes. Moreover, if the system crashes
at this point, the situation could persist after crash recovery, and
the contents of the non-updated column would be permanently lost.

The problem is amplified by the ROW_FORMAT=DYNAMIC and
ROW_FORMAT=COMPRESSED that were introduced in
innodb_file_format=barracuda in InnoDB Plugin, but the bug does exist
in all InnoDB versions.

The fix is as follows. After a pessimistic B-tree operation that needs
to write out off-page columns, allocate the pages for these columns in
the mini-transaction that performed the B-tree operation (btr_mtr),
but write the pages in a separate mini-transaction (blob_mtr). Do
mtr_commit(blob_mtr) before mtr_commit(btr_mtr). A quirk: Do not reuse
pages that were previously freed in btr_mtr. Only write the off-page
columns to 'fresh' pages.

In this way, crash recovery will see redo log entries for blob_mtr
before any redo log entry for btr_mtr. It will apply the BLOB page
writes to pages that were marked free at that point. If crash recovery
fails to see all of the btr_mtr redo log, there will be some
unreachable BLOB data in free pages, but the B-tree will be in a
consistent state.

btr_page_alloc_low(): Renamed from btr_page_alloc(). Add the parameter
init_mtr. Return an allocated block, or NULL. If init_mtr!=mtr but
the page was already X-latched in mtr, do not initialize the page.

btr_page_alloc(): Wrapper for btr_page_alloc_for_ibuf() and
btr_page_alloc_low().

btr_page_free(): Add a debug assertion that the page was a B-tree page.

btr_lift_page_up(): Return the father block.

btr_compress(), btr_cur_compress_if_useful(): Add the parameter ibool
adjust, for adjusting the cursor position.

btr_cur_pessimistic_update(): Preserve the cursor position when
big_rec will be written and the new flag BTR_KEEP_POS_FLAG is defined.
Remove a duplicate rec_get_offsets() call. Keep the X-latch on
index->lock when big_rec is needed.

btr_store_big_rec_extern_fields(): Replace update_inplace with
an operation code, and local_mtr with btr_mtr. When not doing a
fresh insert and btr_mtr has freed pages, put aside any pages that
were previously X-latched in btr_mtr, and free the pages after
writing out all data. The data must be written to 'fresh' pages,
because btr_mtr will be committed and written to the redo log after
the BLOB writes have been written to the redo log.

btr_blob_op_is_update(): Check if an operation passed to
btr_store_big_rec_extern_fields() is an update or insert-by-update.

fseg_alloc_free_page_low(), fsp_alloc_free_page(),
fseg_alloc_free_extent(), fseg_alloc_free_page_general(): Add the
parameter init_mtr. Return an allocated block, or NULL. If
init_mtr!=mtr but the page was already X-latched in mtr, do not
initialize the page.

xdes_get_descriptor_with_space_hdr(): Assert that the file space
header is being X-latched.

fsp_alloc_from_free_frag(): Refactored from fsp_alloc_free_page().

fsp_page_create(): New function, for allocating, X-latching and
potentially initializing a page. If init_mtr!=mtr but the page was
already X-latched in mtr, do not initialize the page.

fsp_free_page(): Add ut_ad(0) to the error outcomes.

fsp_free_page(), fseg_free_page_low(): Increment mtr->n_freed_pages.

fsp_alloc_seg_inode_page(), fseg_create_general(): Assert that the
page was not previously X-latched in the mini-transaction. A file
segment or inode page should never be allocated in the middle of an
mini-transaction that frees pages, such as btr_cur_pessimistic_delete().

fseg_alloc_free_page_low(): If the hinted page was allocated, skip the
check if the tablespace should be extended. Return NULL instead of
FIL_NULL on failure. Remove the flag frag_page_allocated. Instead,
return directly, because the page would already have been initialized.

fseg_find_free_frag_page_slot() would return ULINT_UNDEFINED on error,
not FIL_NULL. Correct a bogus assertion.

fseg_alloc_free_page(): Redefine as a wrapper macro around
fseg_alloc_free_page_general().

buf_block_buf_fix_inc(): Move the definition from the buf0buf.ic to
buf0buf.h, so that it can be called from other modules.

mtr_t: Add n_freed_pages (number of pages that have been freed).

page_rec_get_nth_const(), page_rec_get_nth(): The inverse function of
page_rec_get_n_recs_before(), get the nth record of the record
list. This is faster than iterating the linked list. Refactored from
page_get_middle_rec().

trx_undo_rec_copy(): Add a debug assertion for the length.

trx_undo_add_page(): Return a block descriptor or NULL instead of a
page number or FIL_NULL.

trx_undo_report_row_operation(): Add debug assertions.

trx_sys_create_doublewrite_buf(): Assert that each page was not
previously X-latched.

page_cur_insert_rec_zip_reorg(): Make use of page_rec_get_nth().

row_ins_clust_index_entry_by_modify(): Pass BTR_KEEP_POS_FLAG, so that
the repositioning of the cursor can be avoided.

row_ins_index_entry_low(): Add DEBUG_SYNC points before and after
writing off-page columns. If inserting by updating a delete-marked
record, do not reposition the cursor or commit the mini-transaction
before writing the off-page columns.

row_build(): Tighten a debug assertion about null BLOB pointers.

row_upd_clust_rec(): Add DEBUG_SYNC points before and after writing
off-page columns. Do not reposition the cursor or commit the
mini-transaction before writing the off-page columns.

rb:939 approved by Jimmy Yang
2012-02-17 11:42:04 +02:00

802 lines
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/*****************************************************************************
Copyright (c) 1994, 2012, Oracle and/or its affiliates. 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 Street, Suite 500, Boston, MA 02110-1335 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 */
#define BTR_KEEP_POS_FLAG 8 /* btr_cur_pessimistic_update()
must keep cursor position when
moving columns to big_rec */
#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
BTR_INSERT and 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 */
__attribute__((nonnull, warn_unused_result));
/*************************************************************//**
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/out: cursor on the record to update;
cursor may become invalid if *big_rec == NULL
|| !(flags & BTR_KEEP_POS_FLAG) */
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 */
buf_block_t* block, /*!< in/out: buffer block of the record */
rec_t* rec, /*!< in/out: record */
dict_index_t* index, /*!< in: clustered index of the record */
const ulint* offsets,/*!< in: rec_get_offsets(rec) */
ibool val, /*!< in: value to set */
que_thr_t* thr, /*!< in: query thread */
mtr_t* mtr) /*!< in: mtr */
__attribute__((nonnull));
/***********************************************************//**
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 */
/***********************************************************//**
Clear a secondary index record's delete mark. This function is only
used by the insert buffer insert merge mechanism. */
UNIV_INTERN
void
btr_cur_del_unmark_for_ibuf(
/*========================*/
rec_t* rec, /*!< in/out: record to delete unmark */
page_zip_des_t* page_zip, /*!< in/out: compressed page
corresponding to rec, or NULL
when the tablespace is
uncompressed */
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/out: cursor on the page to compress;
cursor does not stay valid if compression
occurs */
ibool adjust, /*!< in: TRUE if should adjust the
cursor position even if compression occurs */
mtr_t* mtr) /*!< in/out: mini-transaction */
__attribute__((nonnull));
/*******************************************************//**
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.
If innodb_stats_method is nulls_ignored, we also record the number of
non-null values for each prefix and stored the estimates in
array index->stat_n_non_null_key_vals. */
UNIV_INTERN
void
btr_estimate_number_of_different_key_vals(
/*======================================*/
dict_index_t* index); /*!< in: index */
/*******************************************************************//**
Marks non-updated off-page fields as disowned by this record. The ownership
must be 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. */
UNIV_INTERN
void
btr_cur_disown_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/out: mini-transaction */
__attribute__((nonnull(2,3,4,5,6)));
/** Operation code for btr_store_big_rec_extern_fields(). */
enum blob_op {
/** Store off-page columns for a freshly inserted record */
BTR_STORE_INSERT = 0,
/** Store off-page columns for an insert by update */
BTR_STORE_INSERT_UPDATE,
/** Store off-page columns for an update */
BTR_STORE_UPDATE
};
/*******************************************************************//**
Determine if an operation on off-page columns is an update.
@return TRUE if op != BTR_STORE_INSERT */
UNIV_INLINE
ibool
btr_blob_op_is_update(
/*==================*/
enum blob_op op) /*!< in: operation */
__attribute__((warn_unused_result));
/*******************************************************************//**
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
enum db_err
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/out: 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 */
const big_rec_t*big_rec_vec, /*!< in: vector containing fields
to be stored externally */
mtr_t* btr_mtr, /*!< in: mtr containing the
latches to the clustered index */
enum blob_op op) /*! in: operation code */
__attribute__((nonnull, warn_unused_result));
/*******************************************************************//**
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));
/*######################################################################*/
/** 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 */
};
#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 */
};
/** 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 */
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 */
/*------------------------------*/
/* @} */
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
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