/
btr0cur.cc
8693 lines (7378 loc) · 252 KB
/
btr0cur.cc
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/*****************************************************************************
Copyright (c) 1994, 2019, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2008, Google Inc.
Copyright (c) 2012, Facebook Inc.
Copyright (c) 2015, 2022, MariaDB Corporation.
Portions of this file contain modifications contributed and copyrighted by
Google, Inc. Those modifications are gratefully acknowledged and are described
briefly in the InnoDB documentation. The contributions by Google are
incorporated with their permission, and subject to the conditions contained in
the file COPYING.Google.
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 btr/btr0cur.cc
The index tree cursor
All changes that row operations make to a B-tree or the records
there must go through this module! Undo log records are written here
of every modify or insert of a clustered index record.
NOTE!!!
To make sure we do not run out of disk space during a pessimistic
insert or update, we have to reserve 2 x the height of the index tree
many pages in the tablespace before we start the operation, because
if leaf splitting has been started, it is difficult to undo, except
by crashing the database and doing a roll-forward.
Created 10/16/1994 Heikki Tuuri
*******************************************************/
#include "btr0cur.h"
#include "row0upd.h"
#include "mtr0log.h"
#include "page0page.h"
#include "page0zip.h"
#include "rem0rec.h"
#include "rem0cmp.h"
#include "buf0lru.h"
#include "btr0btr.h"
#include "btr0sea.h"
#include "row0log.h"
#include "row0purge.h"
#include "row0upd.h"
#include "trx0rec.h"
#include "trx0roll.h"
#include "que0que.h"
#include "row0row.h"
#include "srv0srv.h"
#include "ibuf0ibuf.h"
#include "lock0lock.h"
#include "zlib.h"
#include "srv0start.h"
#include "mysql_com.h"
#include "dict0stats.h"
#ifdef WITH_WSREP
#include "mysql/service_wsrep.h"
#endif /* WITH_WSREP */
/** Buffered B-tree operation types, introduced as part of delete buffering. */
enum btr_op_t {
BTR_NO_OP = 0, /*!< Not buffered */
BTR_INSERT_OP, /*!< Insert, do not ignore UNIQUE */
BTR_INSERT_IGNORE_UNIQUE_OP, /*!< Insert, ignoring UNIQUE */
BTR_DELETE_OP, /*!< Purge a delete-marked record */
BTR_DELMARK_OP /*!< Mark a record for deletion */
};
/** Modification types for the B-tree operation.
Note that the order must be DELETE, BOTH, INSERT !!
*/
enum btr_intention_t {
BTR_INTENTION_DELETE,
BTR_INTENTION_BOTH,
BTR_INTENTION_INSERT
};
/** For the index->lock scalability improvement, only possibility of clear
performance regression observed was caused by grown huge history list length.
That is because the exclusive use of index->lock also worked as reserving
free blocks and read IO bandwidth with priority. To avoid huge glowing history
list as same level with previous implementation, prioritizes pessimistic tree
operations by purge as the previous, when it seems to be growing huge.
Experimentally, the history list length starts to affect to performance
throughput clearly from about 100000. */
#define BTR_CUR_FINE_HISTORY_LENGTH 100000
/** Number of searches down the B-tree in btr_cur_search_to_nth_level(). */
Atomic_counter<ulint> btr_cur_n_non_sea;
/** Old value of btr_cur_n_non_sea. Copied by
srv_refresh_innodb_monitor_stats(). Referenced by
srv_printf_innodb_monitor(). */
ulint btr_cur_n_non_sea_old;
#ifdef BTR_CUR_HASH_ADAPT
/** Number of successful adaptive hash index lookups in
btr_cur_search_to_nth_level(). */
ulint btr_cur_n_sea;
/** Old value of btr_cur_n_sea. Copied by
srv_refresh_innodb_monitor_stats(). Referenced by
srv_printf_innodb_monitor(). */
ulint btr_cur_n_sea_old;
#endif /* BTR_CUR_HASH_ADAPT */
#ifdef UNIV_DEBUG
/* Flag to limit optimistic insert records */
uint btr_cur_limit_optimistic_insert_debug;
#endif /* UNIV_DEBUG */
/** In the optimistic insert, if the insert does not fit, but this much space
can be released by page reorganize, then it is reorganized */
#define BTR_CUR_PAGE_REORGANIZE_LIMIT (srv_page_size / 32)
/** The structure of a BLOB part header */
/* @{ */
/*--------------------------------------*/
#define BTR_BLOB_HDR_PART_LEN 0 /*!< BLOB part len on this
page */
#define BTR_BLOB_HDR_NEXT_PAGE_NO 4 /*!< next BLOB part page no,
FIL_NULL if none */
/*--------------------------------------*/
#define BTR_BLOB_HDR_SIZE 8 /*!< Size of a BLOB
part header, in bytes */
/** Estimated table level stats from sampled value.
@param value sampled stats
@param index index being sampled
@param sample number of sampled rows
@param ext_size external stored data size
@param not_empty table not empty
@return estimated table wide stats from sampled value */
#define BTR_TABLE_STATS_FROM_SAMPLE(value, index, sample, ext_size, not_empty) \
(((value) * static_cast<ib_uint64_t>(index->stat_n_leaf_pages) \
+ (sample) - 1 + (ext_size) + (not_empty)) / ((sample) + (ext_size)))
/* @} */
/*******************************************************************//**
Marks all extern fields in a record as owned by the record. This function
should be called if the delete mark of a record is removed: a not delete
marked record always owns all its extern fields. */
static
void
btr_cur_unmark_extern_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 rec_offs* offsets,/*!< in: array returned by rec_get_offsets() */
mtr_t* mtr); /*!< in: mtr, or NULL if not logged */
/*******************************************************************//**
Adds path information to the cursor for the current page, for which
the binary search has been performed. */
static
void
btr_cur_add_path_info(
/*==================*/
btr_cur_t* cursor, /*!< in: cursor positioned on a page */
ulint height, /*!< in: height of the page in tree;
0 means leaf node */
ulint root_height); /*!< in: root node height in tree */
/***********************************************************//**
Frees the externally stored fields for a record, if the field is mentioned
in the update vector. */
static
void
btr_rec_free_updated_extern_fields(
/*===============================*/
dict_index_t* index, /*!< in: index of rec; the index tree MUST be
X-latched */
rec_t* rec, /*!< in: record */
page_zip_des_t* page_zip,/*!< in: compressed page whose uncompressed
part will be updated, or NULL */
const rec_offs* offsets,/*!< in: rec_get_offsets(rec, index) */
const upd_t* update, /*!< in: update vector */
bool rollback,/*!< in: performing rollback? */
mtr_t* mtr); /*!< in: mini-transaction handle which contains
an X-latch to record page and to the tree */
/***********************************************************//**
Frees the externally stored fields for a record. */
static
void
btr_rec_free_externally_stored_fields(
/*==================================*/
dict_index_t* index, /*!< in: index of the data, the index
tree MUST be X-latched */
rec_t* rec, /*!< in: record */
const rec_offs* offsets,/*!< in: rec_get_offsets(rec, index) */
page_zip_des_t* page_zip,/*!< in: compressed page whose uncompressed
part will be updated, or NULL */
bool rollback,/*!< in: performing rollback? */
mtr_t* mtr); /*!< in: mini-transaction handle which contains
an X-latch to record page and to the index
tree */
/*==================== B-TREE SEARCH =========================*/
/** Latches the leaf page or pages requested.
@param[in] block leaf page where the search converged
@param[in] page_id page id of the leaf
@param[in] zip_size ROW_FORMAT=COMPRESSED page size, or 0
@param[in] latch_mode BTR_SEARCH_LEAF, ...
@param[in] cursor cursor
@param[in] mtr mini-transaction
@return blocks and savepoints which actually latched. */
btr_latch_leaves_t
btr_cur_latch_leaves(
buf_block_t* block,
const page_id_t page_id,
ulint zip_size,
ulint latch_mode,
btr_cur_t* cursor,
mtr_t* mtr)
{
ulint mode;
ulint left_page_no;
ulint right_page_no;
buf_block_t* get_block;
page_t* page = buf_block_get_frame(block);
bool spatial;
btr_latch_leaves_t latch_leaves = {{NULL, NULL, NULL}, {0, 0, 0}};
compile_time_assert(int(MTR_MEMO_PAGE_S_FIX) == int(RW_S_LATCH));
compile_time_assert(int(MTR_MEMO_PAGE_X_FIX) == int(RW_X_LATCH));
compile_time_assert(int(MTR_MEMO_PAGE_SX_FIX) == int(RW_SX_LATCH));
spatial = dict_index_is_spatial(cursor->index) && cursor->rtr_info;
ut_ad(buf_page_in_file(&block->page));
switch (latch_mode) {
case BTR_SEARCH_LEAF:
case BTR_MODIFY_LEAF:
case BTR_SEARCH_TREE:
if (spatial) {
cursor->rtr_info->tree_savepoints[RTR_MAX_LEVELS]
= mtr_set_savepoint(mtr);
}
mode = latch_mode == BTR_MODIFY_LEAF ? RW_X_LATCH : RW_S_LATCH;
latch_leaves.savepoints[1] = mtr_set_savepoint(mtr);
get_block = btr_block_get(page_id, zip_size, mode,
cursor->index, mtr);
latch_leaves.blocks[1] = get_block;
#ifdef UNIV_BTR_DEBUG
ut_a(page_is_comp(get_block->frame) == page_is_comp(page));
#endif /* UNIV_BTR_DEBUG */
if (spatial) {
cursor->rtr_info->tree_blocks[RTR_MAX_LEVELS]
= get_block;
}
return(latch_leaves);
case BTR_MODIFY_TREE:
/* It is exclusive for other operations which calls
btr_page_set_prev() */
ut_ad(mtr_memo_contains_flagged(
mtr,
dict_index_get_lock(cursor->index),
MTR_MEMO_X_LOCK | MTR_MEMO_SX_LOCK));
/* x-latch also siblings from left to right */
left_page_no = btr_page_get_prev(page);
mode = latch_mode;
if (left_page_no != FIL_NULL) {
if (spatial) {
cursor->rtr_info->tree_savepoints[
RTR_MAX_LEVELS] = mtr_set_savepoint(mtr);
}
latch_leaves.savepoints[0] = mtr_set_savepoint(mtr);
get_block = btr_block_get(
page_id_t(page_id.space(), left_page_no),
zip_size, RW_X_LATCH, cursor->index, mtr);
latch_leaves.blocks[0] = get_block;
if (spatial) {
cursor->rtr_info->tree_blocks[RTR_MAX_LEVELS]
= get_block;
}
}
if (spatial) {
cursor->rtr_info->tree_savepoints[RTR_MAX_LEVELS + 1]
= mtr_set_savepoint(mtr);
}
latch_leaves.savepoints[1] = mtr_set_savepoint(mtr);
get_block = btr_block_get(
page_id, zip_size, RW_X_LATCH, cursor->index, mtr);
latch_leaves.blocks[1] = get_block;
#ifdef UNIV_BTR_DEBUG
/* Sanity check only after both the blocks are latched. */
if (latch_leaves.blocks[0] != NULL) {
ut_a(page_is_comp(latch_leaves.blocks[0]->frame)
== page_is_comp(page));
ut_a(btr_page_get_next(latch_leaves.blocks[0]->frame)
== page_get_page_no(page));
}
ut_a(page_is_comp(get_block->frame) == page_is_comp(page));
#endif /* UNIV_BTR_DEBUG */
if (spatial) {
cursor->rtr_info->tree_blocks[RTR_MAX_LEVELS + 1]
= get_block;
}
right_page_no = btr_page_get_next(page);
if (right_page_no != FIL_NULL) {
if (spatial) {
cursor->rtr_info->tree_savepoints[
RTR_MAX_LEVELS + 2] = mtr_set_savepoint(
mtr);
}
latch_leaves.savepoints[2] = mtr_set_savepoint(mtr);
get_block = btr_block_get(
page_id_t(page_id.space(), right_page_no),
zip_size, RW_X_LATCH, cursor->index, mtr);
latch_leaves.blocks[2] = get_block;
#ifdef UNIV_BTR_DEBUG
if (get_block) {
ut_a(page_is_comp(get_block->frame)
== page_is_comp(page));
ut_a(btr_page_get_prev(get_block->frame)
== page_get_page_no(page));
}
#endif /* UNIV_BTR_DEBUG */
if (spatial) {
cursor->rtr_info->tree_blocks[
RTR_MAX_LEVELS + 2] = get_block;
}
}
return(latch_leaves);
case BTR_SEARCH_PREV:
case BTR_MODIFY_PREV:
mode = latch_mode == BTR_SEARCH_PREV ? RW_S_LATCH : RW_X_LATCH;
/* latch also left sibling */
rw_lock_s_lock(&block->lock);
left_page_no = btr_page_get_prev(page);
rw_lock_s_unlock(&block->lock);
if (left_page_no != FIL_NULL) {
latch_leaves.savepoints[0] = mtr_set_savepoint(mtr);
get_block = btr_block_get(
page_id_t(page_id.space(), left_page_no),
zip_size, mode, cursor->index, mtr);
latch_leaves.blocks[0] = get_block;
cursor->left_block = get_block;
#ifdef UNIV_BTR_DEBUG
ut_a(page_is_comp(get_block->frame)
== page_is_comp(page));
ut_a(btr_page_get_next(get_block->frame)
== page_get_page_no(page));
#endif /* UNIV_BTR_DEBUG */
}
latch_leaves.savepoints[1] = mtr_set_savepoint(mtr);
get_block = btr_block_get(page_id, zip_size, mode,
cursor->index, mtr);
latch_leaves.blocks[1] = get_block;
#ifdef UNIV_BTR_DEBUG
ut_a(page_is_comp(get_block->frame) == page_is_comp(page));
#endif /* UNIV_BTR_DEBUG */
return(latch_leaves);
case BTR_CONT_MODIFY_TREE:
ut_ad(dict_index_is_spatial(cursor->index));
return(latch_leaves);
}
ut_error;
return(latch_leaves);
}
/** Load the instant ALTER TABLE metadata from the clustered index
when loading a table definition.
@param[in,out] index clustered index definition
@param[in,out] mtr mini-transaction
@return error code
@retval DB_SUCCESS if no error occurred
@retval DB_CORRUPTION if any corruption was noticed */
static dberr_t btr_cur_instant_init_low(dict_index_t* index, mtr_t* mtr)
{
ut_ad(index->is_primary());
ut_ad(index->n_core_null_bytes == dict_index_t::NO_CORE_NULL_BYTES);
ut_ad(index->table->supports_instant());
ut_ad(index->table->is_readable());
const fil_space_t* space = index->table->space;
if (!space) {
unreadable:
ib::error() << "Table " << index->table->name
<< " has an unreadable root page";
index->table->corrupted = true;
return DB_CORRUPTION;
}
page_t* root = btr_root_get(index, mtr);
if (!root || btr_cur_instant_root_init(index, root)) {
goto unreadable;
}
ut_ad(index->n_core_null_bytes != dict_index_t::NO_CORE_NULL_BYTES);
if (fil_page_get_type(root) == FIL_PAGE_INDEX) {
ut_ad(!index->is_instant());
return DB_SUCCESS;
}
btr_cur_t cur;
/* Relax the assertion in rec_init_offsets(). */
ut_ad(!index->in_instant_init);
ut_d(index->in_instant_init = true);
dberr_t err = btr_cur_open_at_index_side(true, index, BTR_SEARCH_LEAF,
&cur, 0, mtr);
ut_d(index->in_instant_init = false);
if (err != DB_SUCCESS) {
index->table->corrupted = true;
return err;
}
ut_ad(page_cur_is_before_first(&cur.page_cur));
ut_ad(page_is_leaf(cur.page_cur.block->frame));
page_cur_move_to_next(&cur.page_cur);
const rec_t* rec = cur.page_cur.rec;
const ulint comp = dict_table_is_comp(index->table);
const ulint info_bits = rec_get_info_bits(rec, comp);
if (page_rec_is_supremum(rec)
|| !(info_bits & REC_INFO_MIN_REC_FLAG)) {
if (!index->is_instant()) {
/* The FIL_PAGE_TYPE_INSTANT and PAGE_INSTANT may be
assigned even if instant ADD COLUMN was not
committed. Changes to these page header fields are not
undo-logged, but changes to the hidden metadata record
are. If the server is killed and restarted, the page
header fields could remain set even though no metadata
record is present. */
return DB_SUCCESS;
}
ib::error() << "Table " << index->table->name
<< " is missing instant ALTER metadata";
index->table->corrupted = true;
return DB_CORRUPTION;
}
if ((info_bits & ~REC_INFO_DELETED_FLAG) != REC_INFO_MIN_REC_FLAG
|| (comp && rec_get_status(rec) != REC_STATUS_INSTANT)) {
incompatible:
ib::error() << "Table " << index->table->name
<< " contains unrecognizable instant ALTER metadata";
index->table->corrupted = true;
return DB_CORRUPTION;
}
/* Read the metadata. We can get here on server restart
or when the table was evicted from the data dictionary cache
and is now being accessed again.
Here, READ COMMITTED and REPEATABLE READ should be equivalent.
Committing the ADD COLUMN operation would acquire
MDL_EXCLUSIVE and LOCK_X|LOCK_TABLE, which would prevent any
concurrent operations on the table, including table eviction
from the cache. */
if (info_bits & REC_INFO_DELETED_FLAG) {
/* This metadata record includes a BLOB that identifies
any dropped or reordered columns. */
ulint trx_id_offset = index->trx_id_offset;
/* If !index->trx_id_offset, the PRIMARY KEY contains
variable-length columns. For the metadata record,
variable-length columns should be written with zero
length. However, before MDEV-21088 was fixed, for
variable-length encoded PRIMARY KEY column of type
CHAR, we wrote more than zero bytes. That is why we
must determine the actual length of each PRIMARY KEY
column. The DB_TRX_ID will start right after any
PRIMARY KEY columns. */
ut_ad(index->n_uniq);
/* We cannot invoke rec_get_offsets() before
index->table->deserialise_columns(). Therefore,
we must duplicate some logic here. */
if (trx_id_offset) {
} else if (index->table->not_redundant()) {
/* The PRIMARY KEY contains variable-length columns.
For the metadata record, variable-length columns are
always written with zero length. The DB_TRX_ID will
start right after any fixed-length columns. */
/* OK, before MDEV-21088 was fixed, for
variable-length encoded PRIMARY KEY column of
type CHAR, we wrote more than zero bytes. In
order to allow affected tables to be accessed,
it would be nice to determine the actual
length of each PRIMARY KEY column. However, to
be able to do that, we should determine the
size of the null-bit bitmap in the metadata
record. And we cannot know that before reading
the metadata BLOB, whose starting point we are
trying to find here. (Although the PRIMARY KEY
columns cannot be NULL, we would have to know
where the lengths of variable-length PRIMARY KEY
columns start.)
So, unfortunately we cannot help users who
were affected by MDEV-21088 on a ROW_FORMAT=COMPACT
or ROW_FORMAT=DYNAMIC table. */
for (uint i = index->n_uniq; i--; ) {
trx_id_offset += index->fields[i].fixed_len;
}
} else if (rec_get_1byte_offs_flag(rec)) {
trx_id_offset = rec_1_get_field_end_info(
rec, index->n_uniq - 1);
ut_ad(!(trx_id_offset & REC_1BYTE_SQL_NULL_MASK));
trx_id_offset &= ~REC_1BYTE_SQL_NULL_MASK;
} else {
trx_id_offset = rec_2_get_field_end_info(
rec, index->n_uniq - 1);
ut_ad(!(trx_id_offset & REC_2BYTE_SQL_NULL_MASK));
trx_id_offset &= ~REC_2BYTE_SQL_NULL_MASK;
}
const byte* ptr = rec + trx_id_offset
+ (DATA_TRX_ID_LEN + DATA_ROLL_PTR_LEN);
if (mach_read_from_4(ptr + BTR_EXTERN_LEN)) {
goto incompatible;
}
uint len = mach_read_from_4(ptr + BTR_EXTERN_LEN + 4);
if (!len
|| mach_read_from_4(ptr + BTR_EXTERN_OFFSET)
!= FIL_PAGE_DATA
|| mach_read_from_4(ptr + BTR_EXTERN_SPACE_ID)
!= space->id) {
goto incompatible;
}
buf_block_t* block = buf_page_get(
page_id_t(space->id,
mach_read_from_4(ptr + BTR_EXTERN_PAGE_NO)),
0, RW_S_LATCH, mtr);
buf_block_dbg_add_level(block, SYNC_EXTERN_STORAGE);
if (fil_page_get_type(block->frame) != FIL_PAGE_TYPE_BLOB
|| mach_read_from_4(&block->frame[FIL_PAGE_DATA
+ BTR_BLOB_HDR_NEXT_PAGE_NO])
!= FIL_NULL
|| mach_read_from_4(&block->frame[FIL_PAGE_DATA
+ BTR_BLOB_HDR_PART_LEN])
!= len) {
goto incompatible;
}
/* The unused part of the BLOB page should be zero-filled. */
for (const byte* b = block->frame
+ (FIL_PAGE_DATA + BTR_BLOB_HDR_SIZE) + len,
* const end = block->frame + srv_page_size
- BTR_EXTERN_LEN;
b < end; ) {
if (*b++) {
goto incompatible;
}
}
if (index->table->deserialise_columns(
&block->frame[FIL_PAGE_DATA + BTR_BLOB_HDR_SIZE],
len)) {
goto incompatible;
}
/* Proceed to initialize the default values of
any instantly added columns. */
}
mem_heap_t* heap = NULL;
rec_offs* offsets = rec_get_offsets(rec, index, NULL,
index->n_core_fields,
ULINT_UNDEFINED, &heap);
if (rec_offs_any_default(offsets)) {
inconsistent:
mem_heap_free(heap);
goto incompatible;
}
/* In fact, because we only ever append fields to the metadata
record, it is also OK to perform READ UNCOMMITTED and
then ignore any extra fields, provided that
trx_sys.is_registered(DB_TRX_ID). */
if (rec_offs_n_fields(offsets)
> ulint(index->n_fields) + !!index->table->instant
&& !trx_sys.is_registered(current_trx(),
row_get_rec_trx_id(rec, index,
offsets))) {
goto inconsistent;
}
for (unsigned i = index->n_core_fields; i < index->n_fields; i++) {
dict_col_t* col = index->fields[i].col;
const unsigned o = i + !!index->table->instant;
ulint len;
const byte* data = rec_get_nth_field(rec, offsets, o, &len);
ut_ad(!col->is_added());
ut_ad(!col->def_val.data);
col->def_val.len = len;
switch (len) {
case UNIV_SQL_NULL:
continue;
case 0:
col->def_val.data = field_ref_zero;
continue;
}
ut_ad(len != UNIV_SQL_DEFAULT);
if (!rec_offs_nth_extern(offsets, o)) {
col->def_val.data = mem_heap_dup(
index->table->heap, data, len);
} else if (len < BTR_EXTERN_FIELD_REF_SIZE
|| !memcmp(data + len - BTR_EXTERN_FIELD_REF_SIZE,
field_ref_zero,
BTR_EXTERN_FIELD_REF_SIZE)) {
col->def_val.len = UNIV_SQL_DEFAULT;
goto inconsistent;
} else {
col->def_val.data = btr_copy_externally_stored_field(
&col->def_val.len, data,
cur.page_cur.block->zip_size(),
len, index->table->heap);
}
}
mem_heap_free(heap);
return DB_SUCCESS;
}
/** Load the instant ALTER TABLE metadata from the clustered index
when loading a table definition.
@param[in,out] table table definition from the data dictionary
@return error code
@retval DB_SUCCESS if no error occurred */
dberr_t
btr_cur_instant_init(dict_table_t* table)
{
mtr_t mtr;
dict_index_t* index = dict_table_get_first_index(table);
mtr.start();
dberr_t err = index
? btr_cur_instant_init_low(index, &mtr)
: DB_CORRUPTION;
mtr.commit();
return(err);
}
/** Initialize the n_core_null_bytes on first access to a clustered
index root page.
@param[in] index clustered index that is on its first access
@param[in] page clustered index root page
@return whether the page is corrupted */
bool btr_cur_instant_root_init(dict_index_t* index, const page_t* page)
{
ut_ad(!index->is_dummy);
ut_ad(fil_page_index_page_check(page));
ut_ad(!page_has_siblings(page));
ut_ad(page_get_space_id(page) == index->table->space_id);
ut_ad(page_get_page_no(page) == index->page);
ut_ad(!page_is_comp(page) == !dict_table_is_comp(index->table));
ut_ad(index->is_primary());
ut_ad(!index->is_instant());
ut_ad(index->table->supports_instant());
/* This is normally executed as part of btr_cur_instant_init()
when dict_load_table_one() is loading a table definition.
Other threads should not access or modify the n_core_null_bytes,
n_core_fields before dict_load_table_one() returns.
This can also be executed during IMPORT TABLESPACE, where the
table definition is exclusively locked. */
switch (fil_page_get_type(page)) {
default:
ut_ad(!"wrong page type");
return true;
case FIL_PAGE_INDEX:
/* The field PAGE_INSTANT is guaranteed 0 on clustered
index root pages of ROW_FORMAT=COMPACT or
ROW_FORMAT=DYNAMIC when instant ADD COLUMN is not used. */
ut_ad(!page_is_comp(page) || !page_get_instant(page));
index->n_core_null_bytes = UT_BITS_IN_BYTES(
unsigned(index->n_nullable));
return false;
case FIL_PAGE_TYPE_INSTANT:
break;
}
const uint16_t n = page_get_instant(page);
if (n < index->n_uniq + DATA_ROLL_PTR) {
/* The PRIMARY KEY (or hidden DB_ROW_ID) and
DB_TRX_ID,DB_ROLL_PTR columns must always be present
as 'core' fields. */
return true;
}
if (n > REC_MAX_N_FIELDS) {
return true;
}
index->n_core_fields = n;
const rec_t* infimum = page_get_infimum_rec(page);
const rec_t* supremum = page_get_supremum_rec(page);
if (!memcmp(infimum, "infimum", 8)
&& !memcmp(supremum, "supremum", 8)) {
if (n > index->n_fields) {
/* All fields, including those for instantly
added columns, must be present in the
data dictionary. */
return true;
}
ut_ad(!index->is_dummy);
ut_d(index->is_dummy = true);
index->n_core_null_bytes = UT_BITS_IN_BYTES(
index->get_n_nullable(n));
ut_d(index->is_dummy = false);
return false;
}
if (memcmp(infimum, field_ref_zero, 8)
|| memcmp(supremum, field_ref_zero, 7)) {
/* The infimum and supremum records must either contain
the original strings, or they must be filled with zero
bytes, except for the bytes that we have repurposed. */
return true;
}
index->n_core_null_bytes = supremum[7];
return index->n_core_null_bytes > 128;
}
/** Optimistically latches the leaf page or pages requested.
@param[in] block guessed buffer block
@param[in] modify_clock modify clock value
@param[in,out] latch_mode BTR_SEARCH_LEAF, ...
@param[in,out] cursor cursor
@param[in] file file name
@param[in] line line where called
@param[in] mtr mini-transaction
@return true if success */
bool
btr_cur_optimistic_latch_leaves(
buf_block_t* block,
ib_uint64_t modify_clock,
ulint* latch_mode,
btr_cur_t* cursor,
const char* file,
unsigned line,
mtr_t* mtr)
{
ulint mode;
ulint left_page_no;
ulint curr_page_no;
ut_ad(block->page.buf_fix_count);
ut_ad(buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE);
switch (*latch_mode) {
case BTR_SEARCH_LEAF:
case BTR_MODIFY_LEAF:
return(buf_page_optimistic_get(*latch_mode, block,
modify_clock, file, line, mtr));
case BTR_SEARCH_PREV:
case BTR_MODIFY_PREV:
mode = *latch_mode == BTR_SEARCH_PREV
? RW_S_LATCH : RW_X_LATCH;
rw_lock_s_lock(&block->lock);
if (block->modify_clock != modify_clock) {
rw_lock_s_unlock(&block->lock);
return false;
}
curr_page_no = block->page.id.page_no();
left_page_no = btr_page_get_prev(
buf_block_get_frame(block));
rw_lock_s_unlock(&block->lock);
if (left_page_no != FIL_NULL) {
dberr_t err = DB_SUCCESS;
cursor->left_block = buf_page_get_gen(
page_id_t(cursor->index->table->space_id,
left_page_no),
cursor->index->table->space->zip_size(),
mode, nullptr, BUF_GET_POSSIBLY_FREED,
__FILE__, __LINE__, mtr, &err);
if (err == DB_DECRYPTION_FAILED) {
cursor->index->table->file_unreadable = true;
}
if (btr_page_get_next(cursor->left_block->frame)
!= curr_page_no) {
/* release the left block */
btr_leaf_page_release(
cursor->left_block, mode, mtr);
return false;
}
} else {
cursor->left_block = NULL;
}
if (buf_page_optimistic_get(mode, block, modify_clock,
file, line, mtr)) {
if (btr_page_get_prev(buf_block_get_frame(block))
== left_page_no) {
/* block was already buffer-fixed while
entering the function and
buf_page_optimistic_get() buffer-fixes
it again. */
ut_ad(2 <= block->page.buf_fix_count);
*latch_mode = mode;
return(true);
} else {
/* release the block and decrement of
buf_fix_count which was incremented
in buf_page_optimistic_get() */
btr_leaf_page_release(block, mode, mtr);
}
}
ut_ad(block->page.buf_fix_count);
/* release the left block */
if (cursor->left_block != NULL) {
btr_leaf_page_release(cursor->left_block,
mode, mtr);
}
return(false);
default:
ut_error;
return(false);
}
}
/**
Gets intention in btr_intention_t from latch_mode, and cleares the intention
at the latch_mode.
@param latch_mode in/out: pointer to latch_mode
@return intention for latching tree */
static
btr_intention_t
btr_cur_get_and_clear_intention(
ulint *latch_mode)
{
btr_intention_t intention;
switch (*latch_mode & (BTR_LATCH_FOR_INSERT | BTR_LATCH_FOR_DELETE)) {
case BTR_LATCH_FOR_INSERT:
intention = BTR_INTENTION_INSERT;
break;
case BTR_LATCH_FOR_DELETE:
intention = BTR_INTENTION_DELETE;
break;
default:
/* both or unknown */
intention = BTR_INTENTION_BOTH;
}
*latch_mode &= ulint(~(BTR_LATCH_FOR_INSERT | BTR_LATCH_FOR_DELETE));
return(intention);
}
/**
Gets the desired latch type for the root leaf (root page is root leaf)
at the latch mode.
@param latch_mode in: BTR_SEARCH_LEAF, ...
@return latch type */
static
rw_lock_type_t
btr_cur_latch_for_root_leaf(
ulint latch_mode)
{
switch (latch_mode) {
case BTR_SEARCH_LEAF:
case BTR_SEARCH_TREE:
case BTR_SEARCH_PREV:
return(RW_S_LATCH);
case BTR_MODIFY_LEAF:
case BTR_MODIFY_TREE:
case BTR_MODIFY_PREV:
return(RW_X_LATCH);
case BTR_CONT_MODIFY_TREE:
case BTR_CONT_SEARCH_TREE:
/* A root page should be latched already,
and don't need to be latched here.
fall through (RW_NO_LATCH) */
case BTR_NO_LATCHES:
return(RW_NO_LATCH);
}
ut_error;
return(RW_NO_LATCH); /* avoid compiler warnings */
}
/** Detects whether the modifying record might need a modifying tree structure.
@param[in] index index
@param[in] page page
@param[in] lock_intention lock intention for the tree operation
@param[in] rec record (current node_ptr)
@param[in] rec_size size of the record or max size of node_ptr
@param[in] zip_size ROW_FORMAT=COMPRESSED page size, or 0
@param[in] mtr mtr
@return true if tree modification is needed */
static
bool
btr_cur_will_modify_tree(
dict_index_t* index,
const page_t* page,
btr_intention_t lock_intention,
const rec_t* rec,
ulint rec_size,
ulint zip_size,
mtr_t* mtr)
{
ut_ad(!page_is_leaf(page));
ut_ad(mtr_memo_contains_flagged(mtr, dict_index_get_lock(index),
MTR_MEMO_X_LOCK | MTR_MEMO_SX_LOCK));
/* Pessimistic delete of the first record causes delete & insert
of node_ptr at upper level. And a subsequent page shrink is
possible. It causes delete of node_ptr at the upper level.
So we should pay attention also to 2nd record not only
first record and last record. Because if the "delete & insert" are
done for the different page, the 2nd record become
first record and following compress might delete the record and causes
the uppper level node_ptr modification. */
const ulint n_recs = page_get_n_recs(page);
if (lock_intention <= BTR_INTENTION_BOTH) {
compile_time_assert(BTR_INTENTION_DELETE < BTR_INTENTION_BOTH);
compile_time_assert(BTR_INTENTION_BOTH < BTR_INTENTION_INSERT);
if (!page_has_siblings(page)) {
return true;
}
ulint margin = rec_size;
if (lock_intention == BTR_INTENTION_BOTH) {
ulint level = btr_page_get_level(page);
/* This value is the worst expectation for the node_ptr
records to be deleted from this page. It is used to
expect whether the cursor position can be the left_most
record in this page or not. */
ulint max_nodes_deleted = 0;
/* By modifying tree operations from the under of this
level, logically (2 ^ (level - 1)) opportunities to
deleting records in maximum even unreally rare case. */
if (level > 7) {
/* TODO: adjust this practical limit. */
max_nodes_deleted = 64;
} else if (level > 0) {
max_nodes_deleted = (ulint)1 << (level - 1);
}
/* check delete will cause. (BTR_INTENTION_BOTH
or BTR_INTENTION_DELETE) */
if (n_recs <= max_nodes_deleted * 2
|| page_rec_is_first(rec, page)) {
/* The cursor record can be the left most record
in this page. */
return true;
}
if (page_has_prev(page)
&& page_rec_distance_is_at_most(