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mariadb/storage/innobase/row/row0sel.cc
Marko Mäkelä 6eefeb6fea MDEV-19541: Avoid infinite loop of reading a corrupted page 
row_search_mvcc(): Duplicate the logic of btr_pcur_move_to_next()
so that an infinite loop can be avoided when advancing to the next
page fails due to a corrupted page.
2019-05-29 11:20:56 +03:00

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/*****************************************************************************
Copyright (c) 1997, 2017, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2008, Google Inc.
Copyright (c) 2015, 2019, 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 row/row0sel.cc
Select
Created 12/19/1997 Heikki Tuuri
*******************************************************/
#include "row0sel.h"
#include "dict0dict.h"
#include "dict0boot.h"
#include "trx0undo.h"
#include "trx0trx.h"
#include "btr0btr.h"
#include "btr0cur.h"
#include "btr0sea.h"
#include "gis0rtree.h"
#include "mach0data.h"
#include "que0que.h"
#include "row0upd.h"
#include "row0row.h"
#include "row0vers.h"
#include "rem0cmp.h"
#include "lock0lock.h"
#include "eval0eval.h"
#include "pars0sym.h"
#include "pars0pars.h"
#include "row0mysql.h"
#include "read0read.h"
#include "buf0lru.h"
#include "srv0srv.h"
#include "srv0mon.h"
/* Maximum number of rows to prefetch; MySQL interface has another parameter */
#define SEL_MAX_N_PREFETCH 16
/* Number of rows fetched, after which to start prefetching; MySQL interface
has another parameter */
#define SEL_PREFETCH_LIMIT 1
/* When a select has accessed about this many pages, it returns control back
to que_run_threads: this is to allow canceling runaway queries */
#define SEL_COST_LIMIT 100
/* Flags for search shortcut */
#define SEL_FOUND 0
#define SEL_EXHAUSTED 1
#define SEL_RETRY 2
/********************************************************************//**
Returns TRUE if the user-defined column in a secondary index record
is alphabetically the same as the corresponding BLOB column in the clustered
index record.
NOTE: the comparison is NOT done as a binary comparison, but character
fields are compared with collation!
@return TRUE if the columns are equal */
static
ibool
row_sel_sec_rec_is_for_blob(
/*========================*/
ulint mtype, /*!< in: main type */
ulint prtype, /*!< in: precise type */
ulint mbminlen, /*!< in: minimum length of
a character, in bytes */
ulint mbmaxlen, /*!< in: maximum length of
a character, in bytes */
const byte* clust_field, /*!< in: the locally stored part of
the clustered index column, including
the BLOB pointer; the clustered
index record must be covered by
a lock or a page latch to protect it
against deletion (rollback or purge) */
ulint clust_len, /*!< in: length of clust_field */
const byte* sec_field, /*!< in: column in secondary index */
ulint sec_len, /*!< in: length of sec_field */
ulint prefix_len, /*!< in: index column prefix length
in bytes */
dict_table_t* table) /*!< in: table */
{
ulint len;
byte buf[REC_VERSION_56_MAX_INDEX_COL_LEN];
/* This function should never be invoked on an Antelope format
table, because they should always contain enough prefix in the
clustered index record. */
ut_ad(dict_table_get_format(table) >= UNIV_FORMAT_B);
ut_a(clust_len >= BTR_EXTERN_FIELD_REF_SIZE);
ut_ad(prefix_len >= sec_len);
ut_ad(prefix_len > 0);
ut_a(prefix_len <= sizeof buf);
if (!memcmp(clust_field + clust_len - BTR_EXTERN_FIELD_REF_SIZE,
field_ref_zero, BTR_EXTERN_FIELD_REF_SIZE)) {
/* The externally stored field was not written yet.
This record should only be seen by
recv_recovery_rollback_active() or any
TRX_ISO_READ_UNCOMMITTED transactions. */
return(FALSE);
}
len = btr_copy_externally_stored_field_prefix(
buf, prefix_len, dict_tf_get_page_size(table->flags),
clust_field, clust_len);
if (len == 0) {
/* The BLOB was being deleted as the server crashed.
There should not be any secondary index records
referring to this clustered index record, because
btr_free_externally_stored_field() is called after all
secondary index entries of the row have been purged. */
return(FALSE);
}
len = dtype_get_at_most_n_mbchars(prtype, mbminlen, mbmaxlen,
prefix_len, len, (const char*) buf);
return(!cmp_data_data(mtype, prtype, buf, len, sec_field, sec_len));
}
/** Returns TRUE if the user-defined column values in a secondary index record
are alphabetically the same as the corresponding columns in the clustered
index record.
NOTE: the comparison is NOT done as a binary comparison, but character
fields are compared with collation!
@param[in] sec_rec secondary index record
@param[in] sec_index secondary index
@param[in] clust_rec clustered index record;
must be protected by a page s-latch
@param[in] clust_index clustered index
@param[in] thr query thread
@return TRUE if the secondary record is equal to the corresponding
fields in the clustered record, when compared with collation;
FALSE if not equal or if the clustered record has been marked for deletion */
static
ibool
row_sel_sec_rec_is_for_clust_rec(
const rec_t* sec_rec,
dict_index_t* sec_index,
const rec_t* clust_rec,
dict_index_t* clust_index,
que_thr_t* thr)
{
const byte* sec_field;
ulint sec_len;
const byte* clust_field;
ulint n;
ulint i;
mem_heap_t* heap = NULL;
ulint clust_offsets_[REC_OFFS_NORMAL_SIZE];
ulint sec_offsets_[REC_OFFS_SMALL_SIZE];
ulint* clust_offs = clust_offsets_;
ulint* sec_offs = sec_offsets_;
ibool is_equal = TRUE;
VCOL_STORAGE* vcol_storage= 0;
byte* record;
rec_offs_init(clust_offsets_);
rec_offs_init(sec_offsets_);
if (rec_get_deleted_flag(clust_rec,
dict_table_is_comp(clust_index->table))) {
/* In delete-marked records, DB_TRX_ID must
always refer to an existing undo log record. */
ut_ad(rec_get_trx_id(clust_rec, clust_index));
/* The clustered index record is delete-marked;
it is not visible in the read view. Besides,
if there are any externally stored columns,
some of them may have already been purged. */
return(FALSE);
}
heap = mem_heap_create(256);
clust_offs = rec_get_offsets(clust_rec, clust_index, clust_offs,
true, ULINT_UNDEFINED, &heap);
sec_offs = rec_get_offsets(sec_rec, sec_index, sec_offs,
true, ULINT_UNDEFINED, &heap);
n = dict_index_get_n_ordering_defined_by_user(sec_index);
for (i = 0; i < n; i++) {
const dict_field_t* ifield;
const dict_col_t* col;
ulint clust_pos = 0;
ulint clust_len = 0;
ulint len;
bool is_virtual;
ifield = dict_index_get_nth_field(sec_index, i);
col = dict_field_get_col(ifield);
is_virtual = dict_col_is_virtual(col);
/* For virtual column, its value will need to be
reconstructed from base column in cluster index */
if (is_virtual) {
const dict_v_col_t* v_col;
dfield_t* vfield;
row_ext_t* ext;
if (!vcol_storage)
{
TABLE *mysql_table= thr->prebuilt->m_mysql_table;
innobase_allocate_row_for_vcol(thr_get_trx(thr)->mysql_thd,
clust_index,
&heap,
&mysql_table,
&record,
&vcol_storage);
}
v_col = reinterpret_cast<const dict_v_col_t*>(col);
dtuple_t* row = row_build(
ROW_COPY_POINTERS,
clust_index, clust_rec,
clust_offs,
NULL, NULL, NULL, &ext, heap);
vfield = innobase_get_computed_value(
row, v_col, clust_index,
&heap, NULL, NULL,
thr_get_trx(thr)->mysql_thd,
thr->prebuilt->m_mysql_table,
record, NULL, NULL, NULL);
clust_len = vfield->len;
clust_field = static_cast<byte*>(vfield->data);
} else {
clust_pos = dict_col_get_clust_pos(col, clust_index);
clust_field = rec_get_nth_field(
clust_rec, clust_offs, clust_pos, &clust_len);
}
sec_field = rec_get_nth_field(sec_rec, sec_offs, i, &sec_len);
len = clust_len;
if (ifield->prefix_len > 0 && len != UNIV_SQL_NULL
&& sec_len != UNIV_SQL_NULL && !is_virtual) {
if (rec_offs_nth_extern(clust_offs, clust_pos)) {
len -= BTR_EXTERN_FIELD_REF_SIZE;
}
len = dtype_get_at_most_n_mbchars(
col->prtype, col->mbminlen, col->mbmaxlen,
ifield->prefix_len, len, (char*) clust_field);
if (rec_offs_nth_extern(clust_offs, clust_pos)
&& len < sec_len) {
if (!row_sel_sec_rec_is_for_blob(
col->mtype, col->prtype,
col->mbminlen, col->mbmaxlen,
clust_field, clust_len,
sec_field, sec_len,
ifield->prefix_len,
clust_index->table)) {
goto inequal;
}
continue;
}
}
/* For spatial index, the first field is MBR, we check
if the MBR is equal or not. */
if (dict_index_is_spatial(sec_index) && i == 0) {
rtr_mbr_t tmp_mbr;
rtr_mbr_t sec_mbr;
byte* dptr =
const_cast<byte*>(clust_field);
ut_ad(clust_len != UNIV_SQL_NULL);
/* For externally stored field, we need to get full
geo data to generate the MBR for comparing. */
if (rec_offs_nth_extern(clust_offs, clust_pos)) {
dptr = btr_copy_externally_stored_field(
&clust_len, dptr,
dict_tf_get_page_size(
sec_index->table->flags),
len, heap);
}
rtree_mbr_from_wkb(dptr + GEO_DATA_HEADER_SIZE,
static_cast<uint>(clust_len
- GEO_DATA_HEADER_SIZE),
SPDIMS,
reinterpret_cast<double*>(
&tmp_mbr));
rtr_read_mbr(sec_field, &sec_mbr);
if (!MBR_EQUAL_CMP(&sec_mbr, &tmp_mbr)) {
is_equal = FALSE;
goto func_exit;
}
} else {
if (0 != cmp_data_data(col->mtype, col->prtype,
clust_field, len,
sec_field, sec_len)) {
inequal:
is_equal = FALSE;
goto func_exit;
}
}
}
func_exit:
if (UNIV_LIKELY_NULL(heap)) {
if (UNIV_LIKELY_NULL(vcol_storage))
innobase_free_row_for_vcol(vcol_storage);
mem_heap_free(heap);
}
return(is_equal);
}
/*********************************************************************//**
Creates a select node struct.
@return own: select node struct */
sel_node_t*
sel_node_create(
/*============*/
mem_heap_t* heap) /*!< in: memory heap where created */
{
sel_node_t* node;
node = static_cast<sel_node_t*>(
mem_heap_alloc(heap, sizeof(sel_node_t)));
node->common.type = QUE_NODE_SELECT;
node->state = SEL_NODE_OPEN;
node->plans = NULL;
return(node);
}
/*********************************************************************//**
Frees the memory private to a select node when a query graph is freed,
does not free the heap where the node was originally created. */
void
sel_node_free_private(
/*==================*/
sel_node_t* node) /*!< in: select node struct */
{
ulint i;
plan_t* plan;
if (node->plans != NULL) {
for (i = 0; i < node->n_tables; i++) {
plan = sel_node_get_nth_plan(node, i);
btr_pcur_close(&(plan->pcur));
btr_pcur_close(&(plan->clust_pcur));
if (plan->old_vers_heap) {
mem_heap_free(plan->old_vers_heap);
}
}
}
}
/*********************************************************************//**
Evaluates the values in a select list. If there are aggregate functions,
their argument value is added to the aggregate total. */
UNIV_INLINE
void
sel_eval_select_list(
/*=================*/
sel_node_t* node) /*!< in: select node */
{
que_node_t* exp;
exp = node->select_list;
while (exp) {
eval_exp(exp);
exp = que_node_get_next(exp);
}
}
/*********************************************************************//**
Assigns the values in the select list to the possible into-variables in
SELECT ... INTO ... */
UNIV_INLINE
void
sel_assign_into_var_values(
/*=======================*/
sym_node_t* var, /*!< in: first variable in a list of
variables */
sel_node_t* node) /*!< in: select node */
{
que_node_t* exp;
if (var == NULL) {
return;
}
for (exp = node->select_list;
var != 0;
var = static_cast<sym_node_t*>(que_node_get_next(var))) {
ut_ad(exp);
eval_node_copy_val(var->alias, exp);
exp = que_node_get_next(exp);
}
}
/*********************************************************************//**
Resets the aggregate value totals in the select list of an aggregate type
query. */
UNIV_INLINE
void
sel_reset_aggregate_vals(
/*=====================*/
sel_node_t* node) /*!< in: select node */
{
func_node_t* func_node;
ut_ad(node->is_aggregate);
for (func_node = static_cast<func_node_t*>(node->select_list);
func_node != 0;
func_node = static_cast<func_node_t*>(
que_node_get_next(func_node))) {
eval_node_set_int_val(func_node, 0);
}
node->aggregate_already_fetched = FALSE;
}
/*********************************************************************//**
Copies the input variable values when an explicit cursor is opened. */
UNIV_INLINE
void
row_sel_copy_input_variable_vals(
/*=============================*/
sel_node_t* node) /*!< in: select node */
{
sym_node_t* var;
var = UT_LIST_GET_FIRST(node->copy_variables);
while (var) {
eval_node_copy_val(var, var->alias);
var->indirection = NULL;
var = UT_LIST_GET_NEXT(col_var_list, var);
}
}
/*********************************************************************//**
Fetches the column values from a record. */
static
void
row_sel_fetch_columns(
/*==================*/
dict_index_t* index, /*!< in: record index */
const rec_t* rec, /*!< in: record in a clustered or non-clustered
index; must be protected by a page latch */
const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */
sym_node_t* column) /*!< in: first column in a column list, or
NULL */
{
dfield_t* val;
ulint index_type;
ulint field_no;
const byte* data;
ulint len;
ut_ad(rec_offs_validate(rec, index, offsets));
if (dict_index_is_clust(index)) {
index_type = SYM_CLUST_FIELD_NO;
} else {
index_type = SYM_SEC_FIELD_NO;
}
while (column) {
mem_heap_t* heap = NULL;
ibool needs_copy;
field_no = column->field_nos[index_type];
if (field_no != ULINT_UNDEFINED) {
if (UNIV_UNLIKELY(rec_offs_nth_extern(offsets,
field_no))) {
/* Copy an externally stored field to the
temporary heap, if possible. */
heap = mem_heap_create(1);
data = btr_rec_copy_externally_stored_field(
rec, offsets,
dict_table_page_size(index->table),
field_no, &len, heap);
/* data == NULL means that the
externally stored field was not
written yet. This record
should only be seen by
recv_recovery_rollback_active() or any
TRX_ISO_READ_UNCOMMITTED
transactions. The InnoDB SQL parser
(the sole caller of this function)
does not implement READ UNCOMMITTED,
and it is not involved during rollback. */
ut_a(data);
ut_a(len != UNIV_SQL_NULL);
needs_copy = TRUE;
} else {
data = rec_get_nth_field(rec, offsets,
field_no, &len);
needs_copy = column->copy_val;
}
if (needs_copy) {
eval_node_copy_and_alloc_val(column, data,
len);
} else {
val = que_node_get_val(column);
dfield_set_data(val, data, len);
}
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
}
column = UT_LIST_GET_NEXT(col_var_list, column);
}
}
/*********************************************************************//**
Allocates a prefetch buffer for a column when prefetch is first time done. */
static
void
sel_col_prefetch_buf_alloc(
/*=======================*/
sym_node_t* column) /*!< in: symbol table node for a column */
{
sel_buf_t* sel_buf;
ulint i;
ut_ad(que_node_get_type(column) == QUE_NODE_SYMBOL);
column->prefetch_buf = static_cast<sel_buf_t*>(
ut_malloc_nokey(SEL_MAX_N_PREFETCH * sizeof(sel_buf_t)));
for (i = 0; i < SEL_MAX_N_PREFETCH; i++) {
sel_buf = column->prefetch_buf + i;
sel_buf->data = NULL;
sel_buf->len = 0;
sel_buf->val_buf_size = 0;
}
}
/*********************************************************************//**
Frees a prefetch buffer for a column, including the dynamically allocated
memory for data stored there. */
void
sel_col_prefetch_buf_free(
/*======================*/
sel_buf_t* prefetch_buf) /*!< in, own: prefetch buffer */
{
sel_buf_t* sel_buf;
ulint i;
for (i = 0; i < SEL_MAX_N_PREFETCH; i++) {
sel_buf = prefetch_buf + i;
if (sel_buf->val_buf_size > 0) {
ut_free(sel_buf->data);
}
}
ut_free(prefetch_buf);
}
/*********************************************************************//**
Pops the column values for a prefetched, cached row from the column prefetch
buffers and places them to the val fields in the column nodes. */
static
void
sel_dequeue_prefetched_row(
/*=======================*/
plan_t* plan) /*!< in: plan node for a table */
{
sym_node_t* column;
sel_buf_t* sel_buf;
dfield_t* val;
byte* data;
ulint len;
ulint val_buf_size;
ut_ad(plan->n_rows_prefetched > 0);
column = UT_LIST_GET_FIRST(plan->columns);
while (column) {
val = que_node_get_val(column);
if (!column->copy_val) {
/* We did not really push any value for the
column */
ut_ad(!column->prefetch_buf);
ut_ad(que_node_get_val_buf_size(column) == 0);
ut_d(dfield_set_null(val));
goto next_col;
}
ut_ad(column->prefetch_buf);
ut_ad(!dfield_is_ext(val));
sel_buf = column->prefetch_buf + plan->first_prefetched;
data = sel_buf->data;
len = sel_buf->len;
val_buf_size = sel_buf->val_buf_size;
/* We must keep track of the allocated memory for
column values to be able to free it later: therefore
we swap the values for sel_buf and val */
sel_buf->data = static_cast<byte*>(dfield_get_data(val));
sel_buf->len = dfield_get_len(val);
sel_buf->val_buf_size = que_node_get_val_buf_size(column);
dfield_set_data(val, data, len);
que_node_set_val_buf_size(column, val_buf_size);
next_col:
column = UT_LIST_GET_NEXT(col_var_list, column);
}
plan->n_rows_prefetched--;
plan->first_prefetched++;
}
/*********************************************************************//**
Pushes the column values for a prefetched, cached row to the column prefetch
buffers from the val fields in the column nodes. */
UNIV_INLINE
void
sel_enqueue_prefetched_row(
/*=======================*/
plan_t* plan) /*!< in: plan node for a table */
{
sym_node_t* column;
sel_buf_t* sel_buf;
dfield_t* val;
byte* data;
ulint len;
ulint pos;
ulint val_buf_size;
if (plan->n_rows_prefetched == 0) {
pos = 0;
plan->first_prefetched = 0;
} else {
pos = plan->n_rows_prefetched;
/* We have the convention that pushing new rows starts only
after the prefetch stack has been emptied: */
ut_ad(plan->first_prefetched == 0);
}
plan->n_rows_prefetched++;
ut_ad(pos < SEL_MAX_N_PREFETCH);
for (column = UT_LIST_GET_FIRST(plan->columns);
column != 0;
column = UT_LIST_GET_NEXT(col_var_list, column)) {
if (!column->copy_val) {
/* There is no sense to push pointers to database
page fields when we do not keep latch on the page! */
continue;
}
if (!column->prefetch_buf) {
/* Allocate a new prefetch buffer */
sel_col_prefetch_buf_alloc(column);
}
sel_buf = column->prefetch_buf + pos;
val = que_node_get_val(column);
data = static_cast<byte*>(dfield_get_data(val));
len = dfield_get_len(val);
val_buf_size = que_node_get_val_buf_size(column);
/* We must keep track of the allocated memory for
column values to be able to free it later: therefore
we swap the values for sel_buf and val */
dfield_set_data(val, sel_buf->data, sel_buf->len);
que_node_set_val_buf_size(column, sel_buf->val_buf_size);
sel_buf->data = data;
sel_buf->len = len;
sel_buf->val_buf_size = val_buf_size;
}
}
/*********************************************************************//**
Builds a previous version of a clustered index record for a consistent read
@return DB_SUCCESS or error code */
static MY_ATTRIBUTE((nonnull, warn_unused_result))
dberr_t
row_sel_build_prev_vers(
/*====================*/
ReadView* read_view, /*!< in: read view */
dict_index_t* index, /*!< in: plan node for table */
rec_t* rec, /*!< in: record in a clustered index */
ulint** offsets, /*!< in/out: offsets returned by
rec_get_offsets(rec, plan->index) */
mem_heap_t** offset_heap, /*!< in/out: memory heap from which
the offsets are allocated */
mem_heap_t** old_vers_heap, /*!< out: old version heap to use */
rec_t** old_vers, /*!< out: old version, or NULL if the
record does not exist in the view:
i.e., it was freshly inserted
afterwards */
mtr_t* mtr) /*!< in: mtr */
{
dberr_t err;
if (*old_vers_heap) {
mem_heap_empty(*old_vers_heap);
} else {
*old_vers_heap = mem_heap_create(512);
}
err = row_vers_build_for_consistent_read(
rec, mtr, index, offsets, read_view, offset_heap,
*old_vers_heap, old_vers, NULL);
return(err);
}
/*********************************************************************//**
Builds the last committed version of a clustered index record for a
semi-consistent read. */
static
void
row_sel_build_committed_vers_for_mysql(
/*===================================*/
dict_index_t* clust_index, /*!< in: clustered index */
row_prebuilt_t* prebuilt, /*!< in: prebuilt struct */
const rec_t* rec, /*!< in: record in a clustered index */
ulint** offsets, /*!< in/out: offsets returned by
rec_get_offsets(rec, clust_index) */
mem_heap_t** offset_heap, /*!< in/out: memory heap from which
the offsets are allocated */
const rec_t** old_vers, /*!< out: old version, or NULL if the
record does not exist in the view:
i.e., it was freshly inserted
afterwards */
dtuple_t** vrow, /*!< out: to be filled with old virtual
column version if any */
mtr_t* mtr) /*!< in: mtr */
{
if (prebuilt->old_vers_heap) {
mem_heap_empty(prebuilt->old_vers_heap);
} else {
prebuilt->old_vers_heap = mem_heap_create(
rec_offs_size(*offsets));
}
row_vers_build_for_semi_consistent_read(
rec, mtr, clust_index, offsets, offset_heap,
prebuilt->old_vers_heap, old_vers, vrow);
}
/*********************************************************************//**
Tests the conditions which determine when the index segment we are searching
through has been exhausted.
@return TRUE if row passed the tests */
UNIV_INLINE
ibool
row_sel_test_end_conds(
/*===================*/
plan_t* plan) /*!< in: plan for the table; the column values must
already have been retrieved and the right sides of
comparisons evaluated */
{
func_node_t* cond;
/* All conditions in end_conds are comparisons of a column to an
expression */
for (cond = UT_LIST_GET_FIRST(plan->end_conds);
cond != 0;
cond = UT_LIST_GET_NEXT(cond_list, cond)) {
/* Evaluate the left side of the comparison, i.e., get the
column value if there is an indirection */
eval_sym(static_cast<sym_node_t*>(cond->args));
/* Do the comparison */
if (!eval_cmp(cond)) {
return(FALSE);
}
}
return(TRUE);
}
/*********************************************************************//**
Tests the other conditions.
@return TRUE if row passed the tests */
UNIV_INLINE
ibool
row_sel_test_other_conds(
/*=====================*/
plan_t* plan) /*!< in: plan for the table; the column values must
already have been retrieved */
{
func_node_t* cond;
cond = UT_LIST_GET_FIRST(plan->other_conds);
while (cond) {
eval_exp(cond);
if (!eval_node_get_ibool_val(cond)) {
return(FALSE);
}
cond = UT_LIST_GET_NEXT(cond_list, cond);
}
return(TRUE);
}
/*********************************************************************//**
Retrieves the clustered index record corresponding to a record in a
non-clustered index. Does the necessary locking.
@return DB_SUCCESS or error code */
static MY_ATTRIBUTE((nonnull, warn_unused_result))
dberr_t
row_sel_get_clust_rec(
/*==================*/
sel_node_t* node, /*!< in: select_node */
plan_t* plan, /*!< in: plan node for table */
rec_t* rec, /*!< in: record in a non-clustered index */
que_thr_t* thr, /*!< in: query thread */
rec_t** out_rec,/*!< out: clustered record or an old version of
it, NULL if the old version did not exist
in the read view, i.e., it was a fresh
inserted version */
mtr_t* mtr) /*!< in: mtr used to get access to the
non-clustered record; the same mtr is used to
access the clustered index */
{
dict_index_t* index;
rec_t* clust_rec;
rec_t* old_vers;
dberr_t err;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
rec_offs_init(offsets_);
*out_rec = NULL;
offsets = rec_get_offsets(rec,
btr_pcur_get_btr_cur(&plan->pcur)->index,
offsets, true, ULINT_UNDEFINED, &heap);
row_build_row_ref_fast(plan->clust_ref, plan->clust_map, rec, offsets);
index = dict_table_get_first_index(plan->table);
btr_pcur_open_with_no_init(index, plan->clust_ref, PAGE_CUR_LE,
BTR_SEARCH_LEAF, &plan->clust_pcur,
0, mtr);
clust_rec = btr_pcur_get_rec(&(plan->clust_pcur));
/* Note: only if the search ends up on a non-infimum record is the
low_match value the real match to the search tuple */
if (!page_rec_is_user_rec(clust_rec)
|| btr_pcur_get_low_match(&(plan->clust_pcur))
< dict_index_get_n_unique(index)) {
ut_a(rec_get_deleted_flag(rec,
dict_table_is_comp(plan->table)));
ut_a(node->read_view);
/* In a rare case it is possible that no clust rec is found
for a delete-marked secondary index record: if in row0umod.cc
in row_undo_mod_remove_clust_low() we have already removed
the clust rec, while purge is still cleaning and removing
secondary index records associated with earlier versions of
the clustered index record. In that case we know that the
clustered index record did not exist in the read view of
trx. */
goto func_exit;
}
offsets = rec_get_offsets(clust_rec, index, offsets, true,
ULINT_UNDEFINED, &heap);
if (!node->read_view) {
/* Try to place a lock on the index record */
ulint lock_type;
trx_t* trx;
trx = thr_get_trx(thr);
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using READ COMMITTED or lower isolation level
we lock only the record, i.e., next-key locking is
not used. */
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED) {
lock_type = LOCK_REC_NOT_GAP;
} else {
lock_type = LOCK_ORDINARY;
}
err = lock_clust_rec_read_check_and_lock(
0, btr_pcur_get_block(&plan->clust_pcur),
clust_rec, index, offsets,
static_cast<lock_mode>(node->row_lock_mode),
lock_type,
thr);
switch (err) {
case DB_SUCCESS:
case DB_SUCCESS_LOCKED_REC:
/* Declare the variable uninitialized in Valgrind.
It should be set to DB_SUCCESS at func_exit. */
UNIV_MEM_INVALID(&err, sizeof err);
break;
default:
goto err_exit;
}
} else {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
old_vers = NULL;
if (!lock_clust_rec_cons_read_sees(clust_rec, index, offsets,
node->read_view)) {
err = row_sel_build_prev_vers(
node->read_view, index, clust_rec,
&offsets, &heap, &plan->old_vers_heap,
&old_vers, mtr);
if (err != DB_SUCCESS) {
goto err_exit;
}
clust_rec = old_vers;
if (clust_rec == NULL) {
goto func_exit;
}
}
/* If we had to go to an earlier version of row or the
secondary index record is delete marked, then it may be that
the secondary index record corresponding to clust_rec
(or old_vers) is not rec; in that case we must ignore
such row because in our snapshot rec would not have existed.
Remember that from rec we cannot see directly which transaction
id corresponds to it: we have to go to the clustered index
record. A query where we want to fetch all rows where
the secondary index value is in some interval would return
a wrong result if we would not drop rows which we come to
visit through secondary index records that would not really
exist in our snapshot. */
if ((old_vers
|| rec_get_deleted_flag(rec, dict_table_is_comp(
plan->table)))
&& !row_sel_sec_rec_is_for_clust_rec(rec, plan->index,
clust_rec, index,
thr)) {
goto func_exit;
}
}
/* Fetch the columns needed in test conditions. The clustered
index record is protected by a page latch that was acquired
when plan->clust_pcur was positioned. The latch will not be
released until mtr->commit(). */
ut_ad(!rec_get_deleted_flag(clust_rec, rec_offs_comp(offsets)));
row_sel_fetch_columns(index, clust_rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
*out_rec = clust_rec;
func_exit:
err = DB_SUCCESS;
err_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(err);
}
/*********************************************************************//**
Sets a lock on a page of R-Tree record. This is all or none action,
mostly due to we cannot reposition a record in R-Tree (with the
nature of splitting)
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, or error code */
UNIV_INLINE
dberr_t
sel_set_rtr_rec_lock(
/*=================*/
btr_pcur_t* pcur, /*!< in: cursor */
const rec_t* first_rec,/*!< in: record */
dict_index_t* index, /*!< in: index */
const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */
ulint mode, /*!< in: lock mode */
ulint type, /*!< in: LOCK_ORDINARY, LOCK_GAP, or
LOC_REC_NOT_GAP */
que_thr_t* thr, /*!< in: query thread */
mtr_t* mtr) /*!< in: mtr */
{
matched_rec_t* match = pcur->btr_cur.rtr_info->matches;
mem_heap_t* heap = NULL;
dberr_t err = DB_SUCCESS;
trx_t* trx = thr_get_trx(thr);
buf_block_t* cur_block = btr_pcur_get_block(pcur);
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* my_offsets = const_cast<ulint*>(offsets);
rec_t* rec = const_cast<rec_t*>(first_rec);
rtr_rec_vector* match_rec;
rtr_rec_vector::iterator end;
rec_offs_init(offsets_);
if (match->locked || page_rec_is_supremum(first_rec)) {
return(DB_SUCCESS_LOCKED_REC);
}
ut_ad(page_align(first_rec) == cur_block->frame);
ut_ad(match->valid);
rw_lock_x_lock(&(match->block.lock));
retry:
cur_block = btr_pcur_get_block(pcur);
ut_ad(rw_lock_own_flagged(&match->block.lock,
RW_LOCK_FLAG_X | RW_LOCK_FLAG_S));
ut_ad(page_is_leaf(buf_block_get_frame(cur_block)));
err = lock_sec_rec_read_check_and_lock(
0, cur_block, rec, index, my_offsets,
static_cast<lock_mode>(mode), type, thr);
if (err == DB_LOCK_WAIT) {
re_scan:
mtr->commit();
trx->error_state = err;
que_thr_stop_for_mysql(thr);
thr->lock_state = QUE_THR_LOCK_ROW;
if (row_mysql_handle_errors(
&err, trx, thr, NULL)) {
thr->lock_state = QUE_THR_LOCK_NOLOCK;
mtr->start();
mutex_enter(&match->rtr_match_mutex);
if (!match->valid && match->matched_recs->empty()) {
mutex_exit(&match->rtr_match_mutex);
err = DB_RECORD_NOT_FOUND;
goto func_end;
}
mutex_exit(&match->rtr_match_mutex);
ulint page_no = page_get_page_no(
btr_pcur_get_page(pcur));
page_id_t page_id(dict_index_get_space(index),
page_no);
cur_block = buf_page_get_gen(
page_id, dict_table_page_size(index->table),
RW_X_LATCH, NULL, BUF_GET,
__FILE__, __LINE__, mtr, &err);
} else {
mtr->start();
goto func_end;
}
DEBUG_SYNC_C("rtr_set_lock_wait");
if (!match->valid) {
/* Page got deleted */
mtr->commit();
mtr->start();
err = DB_RECORD_NOT_FOUND;
goto func_end;
}
match->matched_recs->clear();
rtr_cur_search_with_match(
cur_block, index,
pcur->btr_cur.rtr_info->search_tuple,
pcur->btr_cur.rtr_info->search_mode,
&pcur->btr_cur.page_cur,
pcur->btr_cur.rtr_info);
if (!page_is_leaf(buf_block_get_frame(cur_block))) {
/* Page got splitted and promoted (only for
root page it is possible). Release the
page and ask for a re-search */
mtr->commit();
mtr->start();
err = DB_RECORD_NOT_FOUND;
goto func_end;
}
rec = btr_pcur_get_rec(pcur);
my_offsets = offsets_;
my_offsets = rec_get_offsets(rec, index, my_offsets, true,
ULINT_UNDEFINED, &heap);
/* No match record */
if (page_rec_is_supremum(rec) || !match->valid) {
mtr->commit();
mtr->start();
err = DB_RECORD_NOT_FOUND;
goto func_end;
}
goto retry;
}
my_offsets = offsets_;
match_rec = match->matched_recs;
end = match_rec->end();
for (rtr_rec_vector::iterator it = match_rec->begin();
it != end; ++it) {
rtr_rec_t* rtr_rec = &(*it);
my_offsets = rec_get_offsets(
rtr_rec->r_rec, index, my_offsets, true,
ULINT_UNDEFINED, &heap);
err = lock_sec_rec_read_check_and_lock(
0, &match->block, rtr_rec->r_rec, index,
my_offsets, static_cast<lock_mode>(mode),
type, thr);
if (err == DB_SUCCESS || err == DB_SUCCESS_LOCKED_REC) {
rtr_rec->locked = true;
} else if (err == DB_LOCK_WAIT) {
goto re_scan;
} else {
goto func_end;
}
}
match->locked = true;
func_end:
rw_lock_x_unlock(&(match->block.lock));
if (heap != NULL) {
mem_heap_free(heap);
}
ut_ad(err != DB_LOCK_WAIT);
return(err);
}
/*********************************************************************//**
Sets a lock on a record.
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, or error code */
UNIV_INLINE
dberr_t
sel_set_rec_lock(
/*=============*/
btr_pcur_t* pcur, /*!< in: cursor */
const rec_t* rec, /*!< in: record */
dict_index_t* index, /*!< in: index */
const ulint* offsets,/*!< in: rec_get_offsets(rec, index) */
ulint mode, /*!< in: lock mode */
ulint type, /*!< in: LOCK_ORDINARY, LOCK_GAP, or
LOC_REC_NOT_GAP */
que_thr_t* thr, /*!< in: query thread */
mtr_t* mtr) /*!< in: mtr */
{
trx_t* trx;
dberr_t err = DB_SUCCESS;
const buf_block_t* block;
block = btr_pcur_get_block(pcur);
trx = thr_get_trx(thr);
if (UT_LIST_GET_LEN(trx->lock.trx_locks) > 10000) {
if (buf_LRU_buf_pool_running_out()) {
return(DB_LOCK_TABLE_FULL);
}
}
if (dict_index_is_clust(index)) {
err = lock_clust_rec_read_check_and_lock(
0, block, rec, index, offsets,
static_cast<lock_mode>(mode), type, thr);
} else {
if (dict_index_is_spatial(index)) {
if (type == LOCK_GAP || type == LOCK_ORDINARY) {
ut_ad(0);
ib::error() << "Incorrectly request GAP lock "
"on RTree";
return(DB_SUCCESS);
}
err = sel_set_rtr_rec_lock(pcur, rec, index, offsets,
mode, type, thr, mtr);
} else {
err = lock_sec_rec_read_check_and_lock(
0, block, rec, index, offsets,
static_cast<lock_mode>(mode), type, thr);
}
}
return(err);
}
/*********************************************************************//**
Opens a pcur to a table index. */
static
void
row_sel_open_pcur(
/*==============*/
plan_t* plan, /*!< in: table plan */
ibool search_latch_locked,
/*!< in: TRUE if the thread currently
has the search latch locked in
s-mode */
mtr_t* mtr) /*!< in: mtr */
{
dict_index_t* index;
func_node_t* cond;
que_node_t* exp;
ulint n_fields;
ulint has_search_latch = 0; /* RW_S_LATCH or 0 */
ulint i;
if (search_latch_locked) {
has_search_latch = RW_S_LATCH;
}
index = plan->index;
/* Calculate the value of the search tuple: the exact match columns
get their expressions evaluated when we evaluate the right sides of
end_conds */
cond = UT_LIST_GET_FIRST(plan->end_conds);
while (cond) {
eval_exp(que_node_get_next(cond->args));
cond = UT_LIST_GET_NEXT(cond_list, cond);
}
if (plan->tuple) {
n_fields = dtuple_get_n_fields(plan->tuple);
if (plan->n_exact_match < n_fields) {
/* There is a non-exact match field which must be
evaluated separately */
eval_exp(plan->tuple_exps[n_fields - 1]);
}
for (i = 0; i < n_fields; i++) {
exp = plan->tuple_exps[i];
dfield_copy_data(dtuple_get_nth_field(plan->tuple, i),
que_node_get_val(exp));
}
/* Open pcur to the index */
btr_pcur_open_with_no_init(index, plan->tuple, plan->mode,
BTR_SEARCH_LEAF, &plan->pcur,
has_search_latch, mtr);
} else {
/* Open the cursor to the start or the end of the index
(FALSE: no init) */
btr_pcur_open_at_index_side(plan->asc, index, BTR_SEARCH_LEAF,
&(plan->pcur), false, 0, mtr);
}
ut_ad(plan->n_rows_prefetched == 0);
ut_ad(plan->n_rows_fetched == 0);
ut_ad(plan->cursor_at_end == FALSE);
plan->pcur_is_open = TRUE;
}
/*********************************************************************//**
Restores a stored pcur position to a table index.
@return TRUE if the cursor should be moved to the next record after we
return from this function (moved to the previous, in the case of a
descending cursor) without processing again the current cursor
record */
static
ibool
row_sel_restore_pcur_pos(
/*=====================*/
plan_t* plan, /*!< in: table plan */
mtr_t* mtr) /*!< in: mtr */
{
ibool equal_position;
ulint relative_position;
ut_ad(!plan->cursor_at_end);
relative_position = btr_pcur_get_rel_pos(&(plan->pcur));
equal_position = btr_pcur_restore_position(BTR_SEARCH_LEAF,
&(plan->pcur), mtr);
/* If the cursor is traveling upwards, and relative_position is
(1) BTR_PCUR_BEFORE: this is not allowed, as we did not have a lock
yet on the successor of the page infimum;
(2) BTR_PCUR_AFTER: btr_pcur_restore_position placed the cursor on the
first record GREATER than the predecessor of a page supremum; we have
not yet processed the cursor record: no need to move the cursor to the
next record;
(3) BTR_PCUR_ON: btr_pcur_restore_position placed the cursor on the
last record LESS or EQUAL to the old stored user record; (a) if
equal_position is FALSE, this means that the cursor is now on a record
less than the old user record, and we must move to the next record;
(b) if equal_position is TRUE, then if
plan->stored_cursor_rec_processed is TRUE, we must move to the next
record, else there is no need to move the cursor. */
if (plan->asc) {
if (relative_position == BTR_PCUR_ON) {
if (equal_position) {
return(plan->stored_cursor_rec_processed);
}
return(TRUE);
}
ut_ad(relative_position == BTR_PCUR_AFTER
|| relative_position == BTR_PCUR_AFTER_LAST_IN_TREE);
return(FALSE);
}
/* If the cursor is traveling downwards, and relative_position is
(1) BTR_PCUR_BEFORE: btr_pcur_restore_position placed the cursor on
the last record LESS than the successor of a page infimum; we have not
processed the cursor record: no need to move the cursor;
(2) BTR_PCUR_AFTER: btr_pcur_restore_position placed the cursor on the
first record GREATER than the predecessor of a page supremum; we have
processed the cursor record: we should move the cursor to the previous
record;
(3) BTR_PCUR_ON: btr_pcur_restore_position placed the cursor on the
last record LESS or EQUAL to the old stored user record; (a) if
equal_position is FALSE, this means that the cursor is now on a record
less than the old user record, and we need not move to the previous
record; (b) if equal_position is TRUE, then if
plan->stored_cursor_rec_processed is TRUE, we must move to the previous
record, else there is no need to move the cursor. */
if (relative_position == BTR_PCUR_BEFORE
|| relative_position == BTR_PCUR_BEFORE_FIRST_IN_TREE) {
return(FALSE);
}
if (relative_position == BTR_PCUR_ON) {
if (equal_position) {
return(plan->stored_cursor_rec_processed);
}
return(FALSE);
}
ut_ad(relative_position == BTR_PCUR_AFTER
|| relative_position == BTR_PCUR_AFTER_LAST_IN_TREE);
return(TRUE);
}
/*********************************************************************//**
Resets a plan cursor to a closed state. */
UNIV_INLINE
void
plan_reset_cursor(
/*==============*/
plan_t* plan) /*!< in: plan */
{
plan->pcur_is_open = FALSE;
plan->cursor_at_end = FALSE;
plan->n_rows_fetched = 0;
plan->n_rows_prefetched = 0;
}
#ifdef BTR_CUR_HASH_ADAPT
/*********************************************************************//**
Tries to do a shortcut to fetch a clustered index record with a unique key,
using the hash index if possible (not always).
@return SEL_FOUND, SEL_EXHAUSTED, SEL_RETRY */
static
ulint
row_sel_try_search_shortcut(
/*========================*/
sel_node_t* node, /*!< in: select node for a consistent read */
plan_t* plan, /*!< in: plan for a unique search in clustered
index */
ibool search_latch_locked,
/*!< in: whether the search holds latch on
search system. */
mtr_t* mtr) /*!< in: mtr */
{
dict_index_t* index;
rec_t* rec;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
ulint ret;
rec_offs_init(offsets_);
index = plan->index;
ut_ad(node->read_view);
ut_ad(plan->unique_search);
ut_ad(!plan->must_get_clust);
ut_ad(!search_latch_locked
|| rw_lock_own(btr_get_search_latch(index), RW_LOCK_S));
row_sel_open_pcur(plan, search_latch_locked, mtr);
rec = btr_pcur_get_rec(&(plan->pcur));
if (!page_rec_is_user_rec(rec)) {
return(SEL_RETRY);
}
ut_ad(plan->mode == PAGE_CUR_GE);
/* As the cursor is now placed on a user record after a search with
the mode PAGE_CUR_GE, the up_match field in the cursor tells how many
fields in the user record matched to the search tuple */
if (btr_pcur_get_up_match(&(plan->pcur)) < plan->n_exact_match) {
return(SEL_EXHAUSTED);
}
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
offsets = rec_get_offsets(rec, index, offsets, true,
ULINT_UNDEFINED, &heap);
if (dict_index_is_clust(index)) {
if (!lock_clust_rec_cons_read_sees(rec, index, offsets,
node->read_view)) {
ret = SEL_RETRY;
goto func_exit;
}
} else if (!srv_read_only_mode
&& !lock_sec_rec_cons_read_sees(
rec, index, node->read_view)) {
ret = SEL_RETRY;
goto func_exit;
}
/* Test the deleted flag. */
if (rec_get_deleted_flag(rec, dict_table_is_comp(plan->table))) {
ret = SEL_EXHAUSTED;
goto func_exit;
}
/* Fetch the columns needed in test conditions. The index
record is protected by a page latch that was acquired when
plan->pcur was positioned. The latch will not be released
until mtr->commit(). */
row_sel_fetch_columns(index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
/* Test the rest of search conditions */
if (!row_sel_test_other_conds(plan)) {
ret = SEL_EXHAUSTED;
goto func_exit;
}
ut_ad(plan->pcur.latch_mode == BTR_SEARCH_LEAF);
plan->n_rows_fetched++;
ret = SEL_FOUND;
func_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(ret);
}
#endif /* BTR_CUR_HASH_ADAPT */
/*********************************************************************//**
Performs a select step.
@return DB_SUCCESS or error code */
static MY_ATTRIBUTE((warn_unused_result))
dberr_t
row_sel(
/*====*/
sel_node_t* node, /*!< in: select node */
que_thr_t* thr) /*!< in: query thread */
{
dict_index_t* index;
plan_t* plan;
mtr_t mtr;
ibool moved;
rec_t* rec;
rec_t* old_vers;
rec_t* clust_rec;
ibool consistent_read;
/* The following flag becomes TRUE when we are doing a
consistent read from a non-clustered index and we must look
at the clustered index to find out the previous delete mark
state of the non-clustered record: */
ibool cons_read_requires_clust_rec = FALSE;
ulint cost_counter = 0;
ibool cursor_just_opened;
ibool must_go_to_next;
ibool mtr_has_extra_clust_latch = FALSE;
/* TRUE if the search was made using
a non-clustered index, and we had to
access the clustered record: now &mtr
contains a clustered index latch, and
&mtr must be committed before we move
to the next non-clustered record */
dberr_t err;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
rec_offs_init(offsets_);
ut_ad(thr->run_node == node);
#ifdef BTR_CUR_HASH_ADAPT
ibool search_latch_locked = FALSE;
#else /* BTR_CUR_HASH_ADAPT */
# define search_latch_locked false
#endif /* BTR_CUR_HASH_ADAPT */
if (node->read_view) {
/* In consistent reads, we try to do with the hash index and
not to use the buffer page get. This is to reduce memory bus
load resulting from semaphore operations. The search latch
will be s-locked when we access an index with a unique search
condition, but not locked when we access an index with a
less selective search condition. */
consistent_read = TRUE;
} else {
consistent_read = FALSE;
}
table_loop:
/* TABLE LOOP
----------
This is the outer major loop in calculating a join. We come here when
node->fetch_table changes, and after adding a row to aggregate totals
and, of course, when this function is called. */
ut_ad(mtr_has_extra_clust_latch == FALSE);
plan = sel_node_get_nth_plan(node, node->fetch_table);
index = plan->index;
if (plan->n_rows_prefetched > 0) {
sel_dequeue_prefetched_row(plan);
goto next_table_no_mtr;
}
if (plan->cursor_at_end) {
/* The cursor has already reached the result set end: no more
rows to process for this table cursor, as also the prefetch
stack was empty */
ut_ad(plan->pcur_is_open);
goto table_exhausted_no_mtr;
}
/* Open a cursor to index, or restore an open cursor position */
mtr.start();
#ifdef BTR_CUR_HASH_ADAPT
if (consistent_read && plan->unique_search && !plan->pcur_is_open
&& !plan->must_get_clust) {
if (!search_latch_locked) {
btr_search_s_lock(index);
search_latch_locked = TRUE;
} else if (rw_lock_get_writer(btr_get_search_latch(index))
== RW_LOCK_X_WAIT) {
/* There is an x-latch request waiting: release the
s-latch for a moment; as an s-latch here is often
kept for some 10 searches before being released,
a waiting x-latch request would block other threads
from acquiring an s-latch for a long time, lowering
performance significantly in multiprocessors. */
btr_search_s_unlock(index);
btr_search_s_lock(index);
}
switch (row_sel_try_search_shortcut(node, plan,
search_latch_locked,
&mtr)) {
case SEL_FOUND:
goto next_table;
case SEL_EXHAUSTED:
goto table_exhausted;
default:
ut_ad(0);
case SEL_RETRY:
break;
}
plan_reset_cursor(plan);
mtr.commit();
mtr.start();
}
if (search_latch_locked) {
btr_search_s_unlock(index);
search_latch_locked = FALSE;
}
#endif /* BTR_CUR_HASH_ADAPT */
if (!plan->pcur_is_open) {
/* Evaluate the expressions to build the search tuple and
open the cursor */
row_sel_open_pcur(plan, search_latch_locked, &mtr);
cursor_just_opened = TRUE;
/* A new search was made: increment the cost counter */
cost_counter++;
} else {
/* Restore pcur position to the index */
must_go_to_next = row_sel_restore_pcur_pos(plan, &mtr);
cursor_just_opened = FALSE;
if (must_go_to_next) {
/* We have already processed the cursor record: move
to the next */
goto next_rec;
}
}
rec_loop:
/* RECORD LOOP
-----------
In this loop we use pcur and try to fetch a qualifying row, and
also fill the prefetch buffer for this table if n_rows_fetched has
exceeded a threshold. While we are inside this loop, the following
holds:
(1) &mtr is started,
(2) pcur is positioned and open.
NOTE that if cursor_just_opened is TRUE here, it means that we came
to this point right after row_sel_open_pcur. */
ut_ad(mtr_has_extra_clust_latch == FALSE);
rec = btr_pcur_get_rec(&(plan->pcur));
/* PHASE 1: Set a lock if specified */
if (!node->asc && cursor_just_opened
&& !page_rec_is_supremum(rec)) {
/* Do not support "descending search" for Spatial index */
ut_ad(!dict_index_is_spatial(index));
/* When we open a cursor for a descending search, we must set
a next-key lock on the successor record: otherwise it would
be possible to insert new records next to the cursor position,
and it might be that these new records should appear in the
search result set, resulting in the phantom problem. */
if (!consistent_read) {
rec_t* next_rec = page_rec_get_next(rec);
ulint lock_type;
trx_t* trx;
trx = thr_get_trx(thr);
offsets = rec_get_offsets(next_rec, index, offsets,
true,
ULINT_UNDEFINED, &heap);
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using READ COMMITTED or lower isolation
level, we lock only the record, i.e., next-key
locking is not used. */
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED) {
if (page_rec_is_supremum(next_rec)) {
goto skip_lock;
}
lock_type = LOCK_REC_NOT_GAP;
} else {
lock_type = LOCK_ORDINARY;
}
err = sel_set_rec_lock(&plan->pcur,
next_rec, index, offsets,
node->row_lock_mode,
lock_type, thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
/* fall through */
case DB_SUCCESS:
break;
default:
/* Note that in this case we will store in pcur
the PREDECESSOR of the record we are waiting
the lock for */
goto lock_wait_or_error;
}
}
}
skip_lock:
if (page_rec_is_infimum(rec)) {
/* The infimum record on a page cannot be in the result set,
and neither can a record lock be placed on it: we skip such
a record. We also increment the cost counter as we may have
processed yet another page of index. */
cost_counter++;
goto next_rec;
}
if (!consistent_read) {
/* Try to place a lock on the index record */
ulint lock_type;
trx_t* trx;
offsets = rec_get_offsets(rec, index, offsets, true,
ULINT_UNDEFINED, &heap);
trx = thr_get_trx(thr);
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using READ COMMITTED or lower isolation level,
we lock only the record, i.e., next-key locking is
not used. */
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED
|| dict_index_is_spatial(index)) {
if (page_rec_is_supremum(rec)) {
goto next_rec;
}
lock_type = LOCK_REC_NOT_GAP;
} else {
lock_type = LOCK_ORDINARY;
}
err = sel_set_rec_lock(&plan->pcur,
rec, index, offsets,
node->row_lock_mode, lock_type,
thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
/* fall through */
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
if (page_rec_is_supremum(rec)) {
/* A page supremum record cannot be in the result set: skip
it now when we have placed a possible lock on it */
goto next_rec;
}
ut_ad(page_rec_is_user_rec(rec));
if (cost_counter > SEL_COST_LIMIT) {
/* Now that we have placed the necessary locks, we can stop
for a while and store the cursor position; NOTE that if we
would store the cursor position BEFORE placing a record lock,
it might happen that the cursor would jump over some records
that another transaction could meanwhile insert adjacent to
the cursor: this would result in the phantom problem. */
goto stop_for_a_while;
}
/* PHASE 2: Check a mixed index mix id if needed */
if (plan->unique_search && cursor_just_opened) {
ut_ad(plan->mode == PAGE_CUR_GE);
/* As the cursor is now placed on a user record after a search
with the mode PAGE_CUR_GE, the up_match field in the cursor
tells how many fields in the user record matched to the search
tuple */
if (btr_pcur_get_up_match(&(plan->pcur))
< plan->n_exact_match) {
goto table_exhausted;
}
/* Ok, no need to test end_conds or mix id */
}
/* We are ready to look at a possible new index entry in the result
set: the cursor is now placed on a user record */
/* PHASE 3: Get previous version in a consistent read */
cons_read_requires_clust_rec = FALSE;
offsets = rec_get_offsets(rec, index, offsets, true,
ULINT_UNDEFINED, &heap);
if (consistent_read) {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
if (dict_index_is_clust(index)) {
if (!lock_clust_rec_cons_read_sees(
rec, index, offsets, node->read_view)) {
err = row_sel_build_prev_vers(
node->read_view, index, rec,
&offsets, &heap, &plan->old_vers_heap,
&old_vers, &mtr);
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
if (old_vers == NULL) {
/* The record does not exist
in our read view. Skip it, but
first attempt to determine
whether the index segment we
are searching through has been
exhausted. */
offsets = rec_get_offsets(
rec, index, offsets, true,
ULINT_UNDEFINED, &heap);
/* Fetch the columns needed in
test conditions. The clustered
index record is protected by a
page latch that was acquired
by row_sel_open_pcur() or
row_sel_restore_pcur_pos().
The latch will not be released
until mtr.commit(). */
row_sel_fetch_columns(
index, rec, offsets,
UT_LIST_GET_FIRST(
plan->columns));
if (!row_sel_test_end_conds(plan)) {
goto table_exhausted;
}
goto next_rec;
}
rec = old_vers;
}
} else if (!srv_read_only_mode
&& !lock_sec_rec_cons_read_sees(
rec, index, node->read_view)) {
cons_read_requires_clust_rec = TRUE;
}
}
/* PHASE 4: Test search end conditions and deleted flag */
/* Fetch the columns needed in test conditions. The record is
protected by a page latch that was acquired by
row_sel_open_pcur() or row_sel_restore_pcur_pos(). The latch
will not be released until mtr.commit(). */
row_sel_fetch_columns(index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
/* Test the selection end conditions: these can only contain columns
which already are found in the index, even though the index might be
non-clustered */
if (plan->unique_search && cursor_just_opened) {
/* No test necessary: the test was already made above */
} else if (!row_sel_test_end_conds(plan)) {
goto table_exhausted;
}
if (rec_get_deleted_flag(rec, dict_table_is_comp(plan->table))
&& !cons_read_requires_clust_rec) {
/* The record is delete marked: we can skip it if this is
not a consistent read which might see an earlier version
of a non-clustered index record */
if (plan->unique_search) {
goto table_exhausted;
}
goto next_rec;
}
/* PHASE 5: Get the clustered index record, if needed and if we did
not do the search using the clustered index */
if (plan->must_get_clust || cons_read_requires_clust_rec) {
/* It was a non-clustered index and we must fetch also the
clustered index record */
err = row_sel_get_clust_rec(node, plan, rec, thr, &clust_rec,
&mtr);
mtr_has_extra_clust_latch = TRUE;
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
/* Retrieving the clustered record required a search:
increment the cost counter */
cost_counter++;
if (clust_rec == NULL) {
/* The record did not exist in the read view */
ut_ad(consistent_read);
goto next_rec;
}
if (rec_get_deleted_flag(clust_rec,
dict_table_is_comp(plan->table))) {
/* In delete-marked records, DB_TRX_ID must
always refer to an existing update_undo log record. */
ut_ad(rec_get_trx_id(clust_rec,
dict_table_get_first_index(
plan->table)));
/* The record is delete marked: we can skip it */
goto next_rec;
}
if (node->can_get_updated) {
btr_pcur_store_position(&(plan->clust_pcur), &mtr);
}
}
/* PHASE 6: Test the rest of search conditions */
if (!row_sel_test_other_conds(plan)) {
if (plan->unique_search) {
goto table_exhausted;
}
goto next_rec;
}
/* PHASE 7: We found a new qualifying row for the current table; push
the row if prefetch is on, or move to the next table in the join */
plan->n_rows_fetched++;
ut_ad(plan->pcur.latch_mode == BTR_SEARCH_LEAF);
if ((plan->n_rows_fetched <= SEL_PREFETCH_LIMIT)
|| plan->unique_search || plan->no_prefetch) {
/* No prefetch in operation: go to the next table */
goto next_table;
}
sel_enqueue_prefetched_row(plan);
if (plan->n_rows_prefetched == SEL_MAX_N_PREFETCH) {
/* The prefetch buffer is now full */
sel_dequeue_prefetched_row(plan);
goto next_table;
}
next_rec:
ut_ad(!search_latch_locked);
if (mtr_has_extra_clust_latch) {
/* We must commit &mtr if we are moving to the next
non-clustered index record, because we could break the
latching order if we would access a different clustered
index page right away without releasing the previous. */
goto commit_mtr_for_a_while;
}
if (node->asc) {
moved = btr_pcur_move_to_next(&(plan->pcur), &mtr);
} else {
moved = btr_pcur_move_to_prev(&(plan->pcur), &mtr);
}
if (!moved) {
goto table_exhausted;
}
cursor_just_opened = FALSE;
/* END OF RECORD LOOP
------------------ */
goto rec_loop;
next_table:
/* We found a record which satisfies the conditions: we can move to
the next table or return a row in the result set */
ut_ad(btr_pcur_is_on_user_rec(&plan->pcur));
if (plan->unique_search && !node->can_get_updated) {
plan->cursor_at_end = TRUE;
} else {
ut_ad(!search_latch_locked);
plan->stored_cursor_rec_processed = TRUE;
btr_pcur_store_position(&(plan->pcur), &mtr);
}
mtr.commit();
mtr_has_extra_clust_latch = FALSE;
next_table_no_mtr:
/* If we use 'goto' to this label, it means that the row was popped
from the prefetched rows stack, and &mtr is already committed */
if (node->fetch_table + 1 == node->n_tables) {
sel_eval_select_list(node);
if (node->is_aggregate) {
goto table_loop;
}
sel_assign_into_var_values(node->into_list, node);
thr->run_node = que_node_get_parent(node);
err = DB_SUCCESS;
goto func_exit;
}
node->fetch_table++;
/* When we move to the next table, we first reset the plan cursor:
we do not care about resetting it when we backtrack from a table */
plan_reset_cursor(sel_node_get_nth_plan(node, node->fetch_table));
goto table_loop;
table_exhausted:
/* The table cursor pcur reached the result set end: backtrack to the
previous table in the join if we do not have cached prefetched rows */
plan->cursor_at_end = TRUE;
mtr.commit();
mtr_has_extra_clust_latch = FALSE;
if (plan->n_rows_prefetched > 0) {
/* The table became exhausted during a prefetch */
sel_dequeue_prefetched_row(plan);
goto next_table_no_mtr;
}
table_exhausted_no_mtr:
if (node->fetch_table == 0) {
err = DB_SUCCESS;
if (node->is_aggregate && !node->aggregate_already_fetched) {
node->aggregate_already_fetched = TRUE;
sel_assign_into_var_values(node->into_list, node);
thr->run_node = que_node_get_parent(node);
} else {
node->state = SEL_NODE_NO_MORE_ROWS;
thr->run_node = que_node_get_parent(node);
}
goto func_exit;
}
node->fetch_table--;
goto table_loop;
stop_for_a_while:
/* Return control for a while to que_run_threads, so that runaway
queries can be canceled. NOTE that when we come here, we must, in a
locking read, have placed the necessary (possibly waiting request)
record lock on the cursor record or its successor: when we reposition
the cursor, this record lock guarantees that nobody can meanwhile have
inserted new records which should have appeared in the result set,
which would result in the phantom problem. */
ut_ad(!search_latch_locked);
plan->stored_cursor_rec_processed = FALSE;
btr_pcur_store_position(&(plan->pcur), &mtr);
mtr.commit();
ut_ad(!sync_check_iterate(sync_check()));
err = DB_SUCCESS;
goto func_exit;
commit_mtr_for_a_while:
/* Stores the cursor position and commits &mtr; this is used if
&mtr may contain latches which would break the latching order if
&mtr would not be committed and the latches released. */
plan->stored_cursor_rec_processed = TRUE;
ut_ad(!search_latch_locked);
btr_pcur_store_position(&(plan->pcur), &mtr);
mtr.commit();
mtr_has_extra_clust_latch = FALSE;
ut_ad(!sync_check_iterate(dict_sync_check()));
goto table_loop;
lock_wait_or_error:
/* See the note at stop_for_a_while: the same holds for this case */
ut_ad(!btr_pcur_is_before_first_on_page(&plan->pcur) || !node->asc);
ut_ad(!search_latch_locked);
plan->stored_cursor_rec_processed = FALSE;
btr_pcur_store_position(&(plan->pcur), &mtr);
mtr.commit();
func_exit:
#ifdef BTR_CUR_HASH_ADAPT
if (search_latch_locked) {
btr_search_s_unlock(index);
}
#endif /* BTR_CUR_HASH_ADAPT */
ut_ad(!sync_check_iterate(dict_sync_check()));
if (heap != NULL) {
mem_heap_free(heap);
}
return(err);
}
/**********************************************************************//**
Performs a select step. This is a high-level function used in SQL execution
graphs.
@return query thread to run next or NULL */
que_thr_t*
row_sel_step(
/*=========*/
que_thr_t* thr) /*!< in: query thread */
{
sel_node_t* node;
ut_ad(thr);
node = static_cast<sel_node_t*>(thr->run_node);
ut_ad(que_node_get_type(node) == QUE_NODE_SELECT);
/* If this is a new time this node is executed (or when execution
resumes after wait for a table intention lock), set intention locks
on the tables, or assign a read view */
if (node->into_list && (thr->prev_node == que_node_get_parent(node))) {
node->state = SEL_NODE_OPEN;
}
if (node->state == SEL_NODE_OPEN) {
/* It may be that the current session has not yet started
its transaction, or it has been committed: */
trx_start_if_not_started_xa(thr_get_trx(thr), false);
plan_reset_cursor(sel_node_get_nth_plan(node, 0));
if (node->consistent_read) {
/* Assign a read view for the query */
trx_assign_read_view(thr_get_trx(thr));
if (thr_get_trx(thr)->read_view != NULL) {
node->read_view = thr_get_trx(thr)->read_view;
} else {
node->read_view = NULL;
}
} else {
sym_node_t* table_node;
lock_mode i_lock_mode;
if (node->set_x_locks) {
i_lock_mode = LOCK_IX;
} else {
i_lock_mode = LOCK_IS;
}
for (table_node = node->table_list;
table_node != 0;
table_node = static_cast<sym_node_t*>(
que_node_get_next(table_node))) {
dberr_t err = lock_table(
0, table_node->table, i_lock_mode,
thr);
if (err != DB_SUCCESS) {
trx_t* trx;
trx = thr_get_trx(thr);
trx->error_state = err;
return(NULL);
}
}
}
/* If this is an explicit cursor, copy stored procedure
variable values, so that the values cannot change between
fetches (currently, we copy them also for non-explicit
cursors) */
if (node->explicit_cursor
&& UT_LIST_GET_FIRST(node->copy_variables)) {
row_sel_copy_input_variable_vals(node);
}
node->state = SEL_NODE_FETCH;
node->fetch_table = 0;
if (node->is_aggregate) {
/* Reset the aggregate total values */
sel_reset_aggregate_vals(node);
}
}
dberr_t err = row_sel(node, thr);
/* NOTE! if queries are parallelized, the following assignment may
have problems; the assignment should be made only if thr is the
only top-level thr in the graph: */
thr->graph->last_sel_node = node;
if (err != DB_SUCCESS) {
thr_get_trx(thr)->error_state = err;
return(NULL);
}
return(thr);
}
/**********************************************************************//**
Performs a fetch for a cursor.
@return query thread to run next or NULL */
que_thr_t*
fetch_step(
/*=======*/
que_thr_t* thr) /*!< in: query thread */
{
sel_node_t* sel_node;
fetch_node_t* node;
ut_ad(thr);
node = static_cast<fetch_node_t*>(thr->run_node);
sel_node = node->cursor_def;
ut_ad(que_node_get_type(node) == QUE_NODE_FETCH);
if (thr->prev_node != que_node_get_parent(node)) {
if (sel_node->state != SEL_NODE_NO_MORE_ROWS) {
if (node->into_list) {
sel_assign_into_var_values(node->into_list,
sel_node);
} else {
ibool ret = (*node->func->func)(
sel_node, node->func->arg);
if (!ret) {
sel_node->state
= SEL_NODE_NO_MORE_ROWS;
}
}
}
thr->run_node = que_node_get_parent(node);
return(thr);
}
/* Make the fetch node the parent of the cursor definition for
the time of the fetch, so that execution knows to return to this
fetch node after a row has been selected or we know that there is
no row left */
sel_node->common.parent = node;
if (sel_node->state == SEL_NODE_CLOSED) {
ib::error() << "fetch called on a closed cursor";
thr_get_trx(thr)->error_state = DB_ERROR;
return(NULL);
}
thr->run_node = sel_node;
return(thr);
}
/***********************************************************//**
Prints a row in a select result.
@return query thread to run next or NULL */
que_thr_t*
row_printf_step(
/*============*/
que_thr_t* thr) /*!< in: query thread */
{
row_printf_node_t* node;
sel_node_t* sel_node;
que_node_t* arg;
ut_ad(thr);
node = static_cast<row_printf_node_t*>(thr->run_node);
sel_node = node->sel_node;
ut_ad(que_node_get_type(node) == QUE_NODE_ROW_PRINTF);
if (thr->prev_node == que_node_get_parent(node)) {
/* Reset the cursor */
sel_node->state = SEL_NODE_OPEN;
/* Fetch next row to print */
thr->run_node = sel_node;
return(thr);
}
if (sel_node->state != SEL_NODE_FETCH) {
ut_ad(sel_node->state == SEL_NODE_NO_MORE_ROWS);
/* No more rows to print */
thr->run_node = que_node_get_parent(node);
return(thr);
}
arg = sel_node->select_list;
while (arg) {
dfield_print_also_hex(que_node_get_val(arg));
fputs(" ::: ", stderr);
arg = que_node_get_next(arg);
}
putc('\n', stderr);
/* Fetch next row to print */
thr->run_node = sel_node;
return(thr);
}
/****************************************************************//**
Converts a key value stored in MySQL format to an Innobase dtuple. The last
field of the key value may be just a prefix of a fixed length field: hence
the parameter key_len. But currently we do not allow search keys where the
last field is only a prefix of the full key field len and print a warning if
such appears. A counterpart of this function is
ha_innobase::store_key_val_for_row() in ha_innodb.cc. */
void
row_sel_convert_mysql_key_to_innobase(
/*==================================*/
dtuple_t* tuple, /*!< in/out: tuple where to build;
NOTE: we assume that the type info
in the tuple is already according
to index! */
byte* buf, /*!< in: buffer to use in field
conversions; NOTE that dtuple->data
may end up pointing inside buf so
do not discard that buffer while
the tuple is being used. See
row_mysql_store_col_in_innobase_format()
in the case of DATA_INT */
ulint buf_len, /*!< in: buffer length */
dict_index_t* index, /*!< in: index of the key value */
const byte* key_ptr, /*!< in: MySQL key value */
ulint key_len, /*!< in: MySQL key value length */
trx_t* trx) /*!< in: transaction */
{
byte* original_buf = buf;
const byte* original_key_ptr = key_ptr;
dict_field_t* field;
dfield_t* dfield;
ulint data_offset;
ulint data_len;
ulint data_field_len;
ibool is_null;
const byte* key_end;
ulint n_fields = 0;
/* For documentation of the key value storage format in MySQL, see
ha_innobase::store_key_val_for_row() in ha_innodb.cc. */
key_end = key_ptr + key_len;
/* Permit us to access any field in the tuple (ULINT_MAX): */
dtuple_set_n_fields(tuple, ULINT_MAX);
dfield = dtuple_get_nth_field(tuple, 0);
field = dict_index_get_nth_field(index, 0);
if (UNIV_UNLIKELY(dfield_get_type(dfield)->mtype == DATA_SYS)) {
/* A special case: we are looking for a position in the
generated clustered index which InnoDB automatically added
to a table with no primary key: the first and the only
ordering column is ROW_ID which InnoDB stored to the key_ptr
buffer. */
ut_a(key_len == DATA_ROW_ID_LEN);
dfield_set_data(dfield, key_ptr, DATA_ROW_ID_LEN);
dtuple_set_n_fields(tuple, 1);
return;
}
while (key_ptr < key_end) {
ulint type = dfield_get_type(dfield)->mtype;
ut_a(field->col->mtype == type);
data_offset = 0;
is_null = FALSE;
if (!(dfield_get_type(dfield)->prtype & DATA_NOT_NULL)) {
/* The first byte in the field tells if this is
an SQL NULL value */
data_offset = 1;
if (*key_ptr != 0) {
dfield_set_null(dfield);
is_null = TRUE;
}
}
/* Calculate data length and data field total length */
if (DATA_LARGE_MTYPE(type) || DATA_GEOMETRY_MTYPE(type)) {
/* For R-tree index, data length should be the
total size of the wkb data.*/
if (dict_index_is_spatial(index)) {
ut_ad(DATA_GEOMETRY_MTYPE(type));
data_len = key_len;
data_field_len = data_offset + data_len;
} else {
/* The key field is a column prefix of a BLOB
or TEXT. */
ut_a(field->prefix_len > 0);
/* MySQL stores the actual data length to the
first 2 bytes after the optional SQL NULL
marker byte. The storage format is
little-endian, that is, the most significant
byte at a higher address. In UTF-8, MySQL
seems to reserve field->prefix_len bytes for
storing this field in the key value buffer,
even though the actual value only takes data
len bytes from the start. */
data_len = key_ptr[data_offset]
+ 256 * key_ptr[data_offset + 1];
data_field_len = data_offset + 2
+ field->prefix_len;
data_offset += 2;
/* Now that we know the length, we store the
column value like it would be a fixed char
field */
}
} else if (field->prefix_len > 0) {
/* Looks like MySQL pads unused end bytes in the
prefix with space. Therefore, also in UTF-8, it is ok
to compare with a prefix containing full prefix_len
bytes, and no need to take at most prefix_len / 3
UTF-8 characters from the start.
If the prefix is used as the upper end of a LIKE
'abc%' query, then MySQL pads the end with chars
0xff. TODO: in that case does it any harm to compare
with the full prefix_len bytes. How do characters
0xff in UTF-8 behave? */
data_len = field->prefix_len;
data_field_len = data_offset + data_len;
} else {
data_len = dfield_get_type(dfield)->len;
data_field_len = data_offset + data_len;
}
if ((dtype_get_mysql_type(dfield_get_type(dfield))
== DATA_MYSQL_TRUE_VARCHAR)
&& (type != DATA_INT)) {
/* In a MySQL key value format, a true VARCHAR is
always preceded by 2 bytes of a length field.
dfield_get_type(dfield)->len returns the maximum
'payload' len in bytes. That does not include the
2 bytes that tell the actual data length.
We added the check != DATA_INT to make sure we do
not treat MySQL ENUM or SET as a true VARCHAR! */
data_len += 2;
data_field_len += 2;
}
/* Storing may use at most data_len bytes of buf */
if (UNIV_LIKELY(!is_null)) {
buf = row_mysql_store_col_in_innobase_format(
dfield, buf,
FALSE, /* MySQL key value format col */
key_ptr + data_offset, data_len,
dict_table_is_comp(index->table));
ut_a(buf <= original_buf + buf_len);
}
key_ptr += data_field_len;
if (UNIV_UNLIKELY(key_ptr > key_end)) {
/* The last field in key was not a complete key field
but a prefix of it.
Print a warning about this! HA_READ_PREFIX_LAST does
not currently work in InnoDB with partial-field key
value prefixes. Since MySQL currently uses a padding
trick to calculate LIKE 'abc%' type queries there
should never be partial-field prefixes in searches. */
ib::warn() << "Using a partial-field key prefix in"
" search, index " << index->name
<< " of table " << index->table->name
<< ". Last data field length "
<< data_field_len << " bytes, key ptr now"
" exceeds key end by " << (key_ptr - key_end)
<< " bytes. Key value in the MySQL format:";
ut_print_buf(stderr, original_key_ptr, key_len);
putc('\n', stderr);
if (!is_null) {
ulint len = dfield_get_len(dfield);
dfield_set_len(dfield, len
- (ulint) (key_ptr - key_end));
}
ut_ad(0);
}
n_fields++;
field++;
dfield++;
}
ut_a(buf <= original_buf + buf_len);
/* We set the length of tuple to n_fields: we assume that the memory
area allocated for it is big enough (usually bigger than n_fields). */
dtuple_set_n_fields(tuple, n_fields);
}
/**************************************************************//**
Stores the row id to the prebuilt struct. */
static
void
row_sel_store_row_id_to_prebuilt(
/*=============================*/
row_prebuilt_t* prebuilt, /*!< in/out: prebuilt */
const rec_t* index_rec, /*!< in: record */
const dict_index_t* index, /*!< in: index of the record */
const ulint* offsets) /*!< in: rec_get_offsets
(index_rec, index) */
{
const byte* data;
ulint len;
ut_ad(rec_offs_validate(index_rec, index, offsets));
data = rec_get_nth_field(
index_rec, offsets,
dict_index_get_sys_col_pos(index, DATA_ROW_ID), &len);
if (UNIV_UNLIKELY(len != DATA_ROW_ID_LEN)) {
ib::error() << "Row id field is wrong length " << len << " in"
" index " << index->name
<< " of table " << index->table->name
<< ", Field number "
<< dict_index_get_sys_col_pos(index, DATA_ROW_ID)
<< ", record:";
rec_print_new(stderr, index_rec, offsets);
putc('\n', stderr);
ut_error;
}
ut_memcpy(prebuilt->row_id, data, len);
}
/**************************************************************//**
Stores a non-SQL-NULL field in the MySQL format. The counterpart of this
function is row_mysql_store_col_in_innobase_format() in row0mysql.cc. */
void
row_sel_field_store_in_mysql_format_func(
byte* dest,
const mysql_row_templ_t* templ,
#ifdef UNIV_DEBUG
const dict_index_t* index,
ulint field_no,
#endif /* UNIV_DEBUG */
const byte* data,
ulint len)
{
byte* ptr;
#ifdef UNIV_DEBUG
const dict_field_t* field
= templ->is_virtual
? NULL : dict_index_get_nth_field(index, field_no);
#endif /* UNIV_DEBUG */
ut_ad(len != UNIV_SQL_NULL);
UNIV_MEM_ASSERT_RW(data, len);
UNIV_MEM_ASSERT_W(dest, templ->mysql_col_len);
UNIV_MEM_INVALID(dest, templ->mysql_col_len);
switch (templ->type) {
const byte* field_end;
byte* pad;
case DATA_INT:
/* Convert integer data from Innobase to a little-endian
format, sign bit restored to normal */
ptr = dest + len;
for (;;) {
ptr--;
*ptr = *data;
if (ptr == dest) {
break;
}
data++;
}
if (!templ->is_unsigned) {
dest[len - 1] = (byte) (dest[len - 1] ^ 128);
}
ut_ad(templ->mysql_col_len == len);
break;
case DATA_VARCHAR:
case DATA_VARMYSQL:
case DATA_BINARY:
field_end = dest + templ->mysql_col_len;
if (templ->mysql_type == DATA_MYSQL_TRUE_VARCHAR) {
/* This is a >= 5.0.3 type true VARCHAR. Store the
length of the data to the first byte or the first
two bytes of dest. */
dest = row_mysql_store_true_var_len(
dest, len, templ->mysql_length_bytes);
/* Copy the actual data. Leave the rest of the
buffer uninitialized. */
memcpy(dest, data, len);
break;
}
/* Copy the actual data */
ut_memcpy(dest, data, len);
/* Pad with trailing spaces. */
pad = dest + len;
ut_ad(templ->mbminlen <= templ->mbmaxlen);
/* We treat some Unicode charset strings specially. */
switch (templ->mbminlen) {
case 4:
/* InnoDB should never have stripped partial
UTF-32 characters. */
ut_a(!(len & 3));
break;
case 2:
/* A space char is two bytes,
0x0020 in UCS2 and UTF-16 */
if (UNIV_UNLIKELY(len & 1)) {
/* A 0x20 has been stripped from the column.
Pad it back. */
if (pad < field_end) {
*pad++ = 0x20;
}
}
}
row_mysql_pad_col(templ->mbminlen, pad, field_end - pad);
break;
case DATA_BLOB:
/* Store a pointer to the BLOB buffer to dest: the BLOB was
already copied to the buffer in row_sel_store_mysql_rec */
row_mysql_store_blob_ref(dest, templ->mysql_col_len, data,
len);
break;
case DATA_GEOMETRY:
/* We store all geometry data as BLOB data at server layer. */
row_mysql_store_geometry(dest, templ->mysql_col_len, data, len);
break;
case DATA_MYSQL:
memcpy(dest, data, len);
ut_ad(templ->mysql_col_len >= len);
ut_ad(templ->mbmaxlen >= templ->mbminlen);
/* If field_no equals to templ->icp_rec_field_no,
we are examining a row pointed by "icp_rec_field_no".
There is possibility that icp_rec_field_no refers to
a field in a secondary index while templ->rec_field_no
points to field in a primary index. The length
should still be equal, unless the field pointed
by icp_rec_field_no has a prefix */
ut_ad(templ->mbmaxlen > templ->mbminlen
|| templ->mysql_col_len == len
|| (field_no == templ->icp_rec_field_no
&& field->prefix_len > 0));
/* The following assertion would fail for old tables
containing UTF-8 ENUM columns due to Bug #9526. */
ut_ad(!templ->mbmaxlen
|| !(templ->mysql_col_len % templ->mbmaxlen));
ut_ad(len * templ->mbmaxlen >= templ->mysql_col_len
|| (field_no == templ->icp_rec_field_no
&& field->prefix_len > 0)
|| templ->rec_field_is_prefix);
ut_ad(templ->is_virtual
|| !(field->prefix_len % templ->mbmaxlen));
if (templ->mbminlen == 1 && templ->mbmaxlen != 1) {
/* Pad with spaces. This undoes the stripping
done in row0mysql.cc, function
row_mysql_store_col_in_innobase_format(). */
memset(dest + len, 0x20, templ->mysql_col_len - len);
}
break;
default:
#ifdef UNIV_DEBUG
case DATA_SYS_CHILD:
case DATA_SYS:
/* These column types should never be shipped to MySQL. */
ut_ad(0);
/* fall through */
case DATA_CHAR:
case DATA_FIXBINARY:
case DATA_FLOAT:
case DATA_DOUBLE:
case DATA_DECIMAL:
/* Above are the valid column types for MySQL data. */
#endif /* UNIV_DEBUG */
ut_ad((templ->is_virtual && !field)
|| (field && field->prefix_len
? field->prefix_len == len
: templ->mysql_col_len == len));
memcpy(dest, data, len);
}
}
#ifdef UNIV_DEBUG
/** Convert a field from Innobase format to MySQL format. */
# define row_sel_store_mysql_field(m,p,r,i,o,f,t) \
row_sel_store_mysql_field_func(m,p,r,i,o,f,t)
#else /* UNIV_DEBUG */
/** Convert a field from Innobase format to MySQL format. */
# define row_sel_store_mysql_field(m,p,r,i,o,f,t) \
row_sel_store_mysql_field_func(m,p,r,o,f,t)
#endif /* UNIV_DEBUG */
/** Convert a field in the Innobase format to a field in the MySQL format.
@param[out] mysql_rec record in the MySQL format
@param[in,out] prebuilt prebuilt struct
@param[in] rec InnoDB record; must be protected
by a page latch
@param[in] index index of rec
@param[in] offsets array returned by rec_get_offsets()
@param[in] field_no templ->rec_field_no or
templ->clust_rec_field_no
or templ->icp_rec_field_no
@param[in] templ row template
*/
static MY_ATTRIBUTE((warn_unused_result))
ibool
row_sel_store_mysql_field_func(
byte* mysql_rec,
row_prebuilt_t* prebuilt,
const rec_t* rec,
#ifdef UNIV_DEBUG
const dict_index_t* index,
#endif
const ulint* offsets,
ulint field_no,
const mysql_row_templ_t*templ)
{
DBUG_ENTER("row_sel_store_mysql_field_func");
const byte* data;
ulint len;
ut_ad(prebuilt->default_rec);
ut_ad(templ);
ut_ad(templ >= prebuilt->mysql_template);
ut_ad(templ < &prebuilt->mysql_template[prebuilt->n_template]);
ut_ad(field_no == templ->clust_rec_field_no
|| field_no == templ->rec_field_no
|| field_no == templ->icp_rec_field_no);
ut_ad(rec_offs_validate(rec, index, offsets));
if (UNIV_UNLIKELY(rec_offs_nth_extern(offsets, field_no))) {
mem_heap_t* heap;
/* Copy an externally stored field to a temporary heap */
ut_ad(field_no == templ->clust_rec_field_no);
if (DATA_LARGE_MTYPE(templ->type)) {
if (prebuilt->blob_heap == NULL) {
prebuilt->blob_heap = mem_heap_create(
UNIV_PAGE_SIZE);
}
heap = prebuilt->blob_heap;
} else {
heap = mem_heap_create(UNIV_PAGE_SIZE);
}
/* NOTE: if we are retrieving a big BLOB, we may
already run out of memory in the next call, which
causes an assert */
data = btr_rec_copy_externally_stored_field(
rec, offsets,
dict_table_page_size(prebuilt->table),
field_no, &len, heap);
if (UNIV_UNLIKELY(!data)) {
/* The externally stored field was not written
yet. This record should only be seen by
recv_recovery_rollback_active() or any
TRX_ISO_READ_UNCOMMITTED transactions. */
if (heap != prebuilt->blob_heap) {
mem_heap_free(heap);
}
ut_a(prebuilt->trx->isolation_level
== TRX_ISO_READ_UNCOMMITTED);
DBUG_RETURN(FALSE);
}
ut_a(len != UNIV_SQL_NULL);
row_sel_field_store_in_mysql_format(
mysql_rec + templ->mysql_col_offset,
templ, index, field_no, data, len);
if (heap != prebuilt->blob_heap) {
mem_heap_free(heap);
}
} else {
/* Field is stored in the row. */
data = rec_get_nth_field(rec, offsets, field_no, &len);
if (len == UNIV_SQL_NULL) {
/* MySQL assumes that the field for an SQL
NULL value is set to the default value. */
ut_ad(templ->mysql_null_bit_mask);
UNIV_MEM_ASSERT_RW(prebuilt->default_rec
+ templ->mysql_col_offset,
templ->mysql_col_len);
mysql_rec[templ->mysql_null_byte_offset]
|= (byte) templ->mysql_null_bit_mask;
memcpy(mysql_rec + templ->mysql_col_offset,
(const byte*) prebuilt->default_rec
+ templ->mysql_col_offset,
templ->mysql_col_len);
DBUG_RETURN(TRUE);
}
if (DATA_LARGE_MTYPE(templ->type)
|| DATA_GEOMETRY_MTYPE(templ->type)) {
/* It is a BLOB field locally stored in the
InnoDB record: we MUST copy its contents to
prebuilt->blob_heap here because
row_sel_field_store_in_mysql_format() stores a
pointer to the data, and the data passed to us
will be invalid as soon as the
mini-transaction is committed and the page
latch on the clustered index page is
released. */
if (prebuilt->blob_heap == NULL) {
prebuilt->blob_heap = mem_heap_create(
UNIV_PAGE_SIZE);
DBUG_PRINT("anna", ("blob_heap allocated: %p",
prebuilt->blob_heap));
}
data = static_cast<byte*>(
mem_heap_dup(prebuilt->blob_heap, data, len));
}
row_sel_field_store_in_mysql_format(
mysql_rec + templ->mysql_col_offset,
templ, index, field_no, data, len);
}
ut_ad(len != UNIV_SQL_NULL);
if (templ->mysql_null_bit_mask) {
/* It is a nullable column with a non-NULL
value */
mysql_rec[templ->mysql_null_byte_offset]
&= ~(byte) templ->mysql_null_bit_mask;
}
DBUG_RETURN(TRUE);
}
/** Convert a row in the Innobase format to a row in the MySQL format.
Note that the template in prebuilt may advise us to copy only a few
columns to mysql_rec, other columns are left blank. All columns may not
be needed in the query.
@param[out] mysql_rec row in the MySQL format
@param[in] prebuilt cursor
@param[in] rec Innobase record in the index
which was described in prebuilt's
template, or in the clustered index;
must be protected by a page latch
@param[in] vrow virtual columns
@param[in] rec_clust whether index must be the clustered index
@param[in] index index of rec
@param[in] offsets array returned by rec_get_offsets(rec)
@retval true on success
@retval false if not all columns could be retrieved */
MY_ATTRIBUTE((warn_unused_result))
static bool row_sel_store_mysql_rec(
byte* mysql_rec,
row_prebuilt_t* prebuilt,
const rec_t* rec,
const dtuple_t* vrow,
bool rec_clust,
const dict_index_t* index,
const ulint* offsets)
{
DBUG_ENTER("row_sel_store_mysql_rec");
ut_ad(rec_clust || index == prebuilt->index);
ut_ad(!rec_clust || dict_index_is_clust(index));
if (UNIV_LIKELY_NULL(prebuilt->blob_heap)) {
row_mysql_prebuilt_free_blob_heap(prebuilt);
}
for (ulint i = 0; i < prebuilt->n_template; i++) {
const mysql_row_templ_t*templ = &prebuilt->mysql_template[i];
if (templ->is_virtual && dict_index_is_clust(index)) {
/* Virtual columns are never declared NOT NULL. */
ut_ad(templ->mysql_null_bit_mask);
/* Skip virtual columns if it is not a covered
search or virtual key read is not requested. */
if (!rec_clust
|| !prebuilt->index->has_virtual()
|| (!prebuilt->read_just_key
&& !prebuilt->m_read_virtual_key)) {
/* Initialize the NULL bit. */
mysql_rec[templ->mysql_null_byte_offset]
|= (byte) templ->mysql_null_bit_mask;
continue;
}
dict_v_col_t* col;
col = dict_table_get_nth_v_col(
index->table, templ->clust_rec_field_no);
ut_ad(vrow);
const dfield_t* dfield = dtuple_get_nth_v_field(
vrow, col->v_pos);
/* If this is a partitioned table, it might request
InnoDB to fill out virtual column data for serach
index key values while other non key columns are also
getting selected. The non-key virtual columns may
not be materialized and we should skip them. */
if (dfield_get_type(dfield)->mtype == DATA_MISSING) {
#ifdef UNIV_DEBUG
ulint prefix;
#endif /* UNIV_DEBUG */
ut_ad(prebuilt->m_read_virtual_key);
/* If it is part of index key the data should
have been materialized. */
ut_ad(dict_index_get_nth_col_or_prefix_pos(
prebuilt->index, col->v_pos, false,
true, &prefix) == ULINT_UNDEFINED);
continue;
}
if (dfield->len == UNIV_SQL_NULL) {
mysql_rec[templ->mysql_null_byte_offset]
|= (byte) templ->mysql_null_bit_mask;
memcpy(mysql_rec
+ templ->mysql_col_offset,
(const byte*) prebuilt->default_rec
+ templ->mysql_col_offset,
templ->mysql_col_len);
} else {
row_sel_field_store_in_mysql_format(
mysql_rec + templ->mysql_col_offset,
templ, index, templ->clust_rec_field_no,
(const byte*)dfield->data, dfield->len);
if (templ->mysql_null_bit_mask) {
mysql_rec[
templ->mysql_null_byte_offset]
&= ~(byte) templ->mysql_null_bit_mask;
}
}
continue;
}
const ulint field_no
= rec_clust
? templ->clust_rec_field_no
: templ->rec_field_no;
/* We should never deliver column prefixes to MySQL,
except for evaluating innobase_index_cond(). */
/* ...actually, we do want to do this in order to
support the prefix query optimization.
ut_ad(dict_index_get_nth_field(index, field_no)->prefix_len
== 0);
...so we disable this assert. */
if (!row_sel_store_mysql_field(mysql_rec, prebuilt,
rec, index, offsets,
field_no, templ)) {
DBUG_RETURN(false);
}
}
/* FIXME: We only need to read the doc_id if an FTS indexed
column is being updated.
NOTE, the record can be cluster or secondary index record.
if secondary index is used then FTS_DOC_ID column should be part
of this index. */
if (dict_table_has_fts_index(prebuilt->table)) {
if (dict_index_is_clust(index)
|| prebuilt->fts_doc_id_in_read_set) {
prebuilt->fts_doc_id = fts_get_doc_id_from_rec(
prebuilt->table, rec, index, NULL);
}
}
DBUG_RETURN(true);
}
/*********************************************************************//**
Builds a previous version of a clustered index record for a consistent read
@return DB_SUCCESS or error code */
static MY_ATTRIBUTE((warn_unused_result))
dberr_t
row_sel_build_prev_vers_for_mysql(
/*==============================*/
ReadView* read_view, /*!< in: read view */
dict_index_t* clust_index, /*!< in: clustered index */
row_prebuilt_t* prebuilt, /*!< in: prebuilt struct */
const rec_t* rec, /*!< in: record in a clustered index */
ulint** offsets, /*!< in/out: offsets returned by
rec_get_offsets(rec, clust_index) */
mem_heap_t** offset_heap, /*!< in/out: memory heap from which
the offsets are allocated */
rec_t** old_vers, /*!< out: old version, or NULL if the
record does not exist in the view:
i.e., it was freshly inserted
afterwards */
dtuple_t** vrow, /*!< out: dtuple to hold old virtual
column data */
mtr_t* mtr) /*!< in: mtr */
{
dberr_t err;
if (prebuilt->old_vers_heap) {
mem_heap_empty(prebuilt->old_vers_heap);
} else {
prebuilt->old_vers_heap = mem_heap_create(200);
}
err = row_vers_build_for_consistent_read(
rec, mtr, clust_index, offsets, read_view, offset_heap,
prebuilt->old_vers_heap, old_vers, vrow);
return(err);
}
/*********************************************************************//**
Retrieves the clustered index record corresponding to a record in a
non-clustered index. Does the necessary locking. Used in the MySQL
interface.
@return DB_SUCCESS, DB_SUCCESS_LOCKED_REC, or error code */
static MY_ATTRIBUTE((warn_unused_result))
dberr_t
row_sel_get_clust_rec_for_mysql(
/*============================*/
row_prebuilt_t* prebuilt,/*!< in: prebuilt struct in the handle */
dict_index_t* sec_index,/*!< in: secondary index where rec resides */
const rec_t* rec, /*!< in: record in a non-clustered index; if
this is a locking read, then rec is not
allowed to be delete-marked, and that would
not make sense either */
que_thr_t* thr, /*!< in: query thread */
const rec_t** out_rec,/*!< out: clustered record or an old version of
it, NULL if the old version did not exist
in the read view, i.e., it was a fresh
inserted version */
ulint** offsets,/*!< in: offsets returned by
rec_get_offsets(rec, sec_index);
out: offsets returned by
rec_get_offsets(out_rec, clust_index) */
mem_heap_t** offset_heap,/*!< in/out: memory heap from which
the offsets are allocated */
dtuple_t** vrow, /*!< out: virtual column to fill */
mtr_t* mtr) /*!< in: mtr used to get access to the
non-clustered record; the same mtr is used to
access the clustered index */
{
dict_index_t* clust_index;
const rec_t* clust_rec;
rec_t* old_vers;
dberr_t err;
trx_t* trx;
*out_rec = NULL;
trx = thr_get_trx(thr);
srv_stats.n_sec_rec_cluster_reads.inc(
thd_get_thread_id(trx->mysql_thd));
row_build_row_ref_in_tuple(prebuilt->clust_ref, rec,
sec_index, *offsets, trx);
clust_index = dict_table_get_first_index(sec_index->table);
btr_pcur_open_with_no_init(clust_index, prebuilt->clust_ref,
PAGE_CUR_LE, BTR_SEARCH_LEAF,
prebuilt->clust_pcur, 0, mtr);
clust_rec = btr_pcur_get_rec(prebuilt->clust_pcur);
prebuilt->clust_pcur->trx_if_known = trx;
/* Note: only if the search ends up on a non-infimum record is the
low_match value the real match to the search tuple */
if (!page_rec_is_user_rec(clust_rec)
|| btr_pcur_get_low_match(prebuilt->clust_pcur)
< dict_index_get_n_unique(clust_index)) {
btr_cur_t* btr_cur = btr_pcur_get_btr_cur(prebuilt->pcur);
/* If this is a spatial index scan, and we are reading
from a shadow buffer, the record could be already
deleted (due to rollback etc.). So get the original
page and verify that */
if (dict_index_is_spatial(sec_index)
&& btr_cur->rtr_info->matches
&& (page_align(rec)
== btr_cur->rtr_info->matches->block.frame
|| rec != btr_pcur_get_rec(prebuilt->pcur))) {
#ifdef UNIV_DEBUG
rtr_info_t* rtr_info = btr_cur->rtr_info;
mutex_enter(&rtr_info->matches->rtr_match_mutex);
/* The page could be deallocated (by rollback etc.) */
if (!rtr_info->matches->valid) {
mutex_exit(&rtr_info->matches->rtr_match_mutex);
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
}
mutex_exit(&rtr_info->matches->rtr_match_mutex);
if (rec_get_deleted_flag(rec,
dict_table_is_comp(sec_index->table))
&& prebuilt->select_lock_type == LOCK_NONE) {
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
}
if (rec != btr_pcur_get_rec(prebuilt->pcur)) {
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
}
/* FIXME: Why is this block not the
same as btr_pcur_get_block(prebuilt->pcur),
and is it not unsafe to use RW_NO_LATCH here? */
buf_block_t* block = buf_page_get_gen(
btr_pcur_get_block(prebuilt->pcur)->page.id,
dict_table_page_size(sec_index->table),
RW_NO_LATCH, NULL, BUF_GET,
__FILE__, __LINE__, mtr, &err);
mem_heap_t* heap = mem_heap_create(256);
dtuple_t* tuple = dict_index_build_data_tuple(
rec, sec_index, true,
sec_index->n_fields, heap);
page_cur_t page_cursor;
ulint low_match = page_cur_search(
block, sec_index, tuple,
PAGE_CUR_LE, &page_cursor);
ut_ad(low_match < dtuple_get_n_fields_cmp(tuple));
mem_heap_free(heap);
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
#endif /* UNIV_DEBUG */
} else if (!rec_get_deleted_flag(rec,
dict_table_is_comp(sec_index->table))
|| prebuilt->select_lock_type != LOCK_NONE) {
/* In a rare case it is possible that no clust
rec is found for a delete-marked secondary index
record: if in row0umod.cc in
row_undo_mod_remove_clust_low() we have already removed
the clust rec, while purge is still cleaning and
removing secondary index records associated with
earlier versions of the clustered index record.
In that case we know that the clustered index
record did not exist in the read view of trx. */
ib::error() << "Clustered record for sec rec not found"
" index " << sec_index->name
<< " of table " << sec_index->table->name;
fputs("InnoDB: sec index record ", stderr);
rec_print(stderr, rec, sec_index);
fputs("\n"
"InnoDB: clust index record ", stderr);
rec_print(stderr, clust_rec, clust_index);
putc('\n', stderr);
trx_print(stderr, trx, 600);
fputs("\n"
"InnoDB: Submit a detailed bug report"
" to https://jira.mariadb.org/\n", stderr);
ut_ad(0);
}
clust_rec = NULL;
err = DB_SUCCESS;
goto func_exit;
}
*offsets = rec_get_offsets(clust_rec, clust_index, *offsets, true,
ULINT_UNDEFINED, offset_heap);
if (prebuilt->select_lock_type != LOCK_NONE) {
/* Try to place a lock on the index record; we are searching
the clust rec with a unique condition, hence
we set a LOCK_REC_NOT_GAP type lock */
err = lock_clust_rec_read_check_and_lock(
0, btr_pcur_get_block(prebuilt->clust_pcur),
clust_rec, clust_index, *offsets,
static_cast<lock_mode>(prebuilt->select_lock_type),
LOCK_REC_NOT_GAP,
thr);
switch (err) {
case DB_SUCCESS:
case DB_SUCCESS_LOCKED_REC:
break;
default:
goto err_exit;
}
} else {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
old_vers = NULL;
/* If the isolation level allows reading of uncommitted data,
then we never look for an earlier version */
if (trx->isolation_level > TRX_ISO_READ_UNCOMMITTED
&& !lock_clust_rec_cons_read_sees(
clust_rec, clust_index, *offsets,
trx_get_read_view(trx))) {
/* The following call returns 'offsets' associated with
'old_vers' */
err = row_sel_build_prev_vers_for_mysql(
trx->read_view, clust_index, prebuilt,
clust_rec, offsets, offset_heap, &old_vers,
vrow, mtr);
if (err != DB_SUCCESS || old_vers == NULL) {
goto err_exit;
}
clust_rec = old_vers;
}
/* If we had to go to an earlier version of row or the
secondary index record is delete marked, then it may be that
the secondary index record corresponding to clust_rec
(or old_vers) is not rec; in that case we must ignore
such row because in our snapshot rec would not have existed.
Remember that from rec we cannot see directly which transaction
id corresponds to it: we have to go to the clustered index
record. A query where we want to fetch all rows where
the secondary index value is in some interval would return
a wrong result if we would not drop rows which we come to
visit through secondary index records that would not really
exist in our snapshot. */
/* And for spatial index, since the rec is from shadow buffer,
so we need to check if it's exactly match the clust_rec. */
if (clust_rec
&& (old_vers
|| trx->isolation_level <= TRX_ISO_READ_UNCOMMITTED
|| dict_index_is_spatial(sec_index)
|| rec_get_deleted_flag(rec, dict_table_is_comp(
sec_index->table)))
&& !row_sel_sec_rec_is_for_clust_rec(
rec, sec_index, clust_rec, clust_index, thr)) {
clust_rec = NULL;
}
err = DB_SUCCESS;
}
func_exit:
*out_rec = clust_rec;
if (prebuilt->select_lock_type != LOCK_NONE) {
/* We may use the cursor in update or in unlock_row():
store its position */
btr_pcur_store_position(prebuilt->clust_pcur, mtr);
}
err_exit:
return(err);
}
/********************************************************************//**
Restores cursor position after it has been stored. We have to take into
account that the record cursor was positioned on may have been deleted.
Then we may have to move the cursor one step up or down.
@return TRUE if we may need to process the record the cursor is now
positioned on (i.e. we should not go to the next record yet) */
static
ibool
sel_restore_position_for_mysql(
/*===========================*/
ibool* same_user_rec, /*!< out: TRUE if we were able to restore
the cursor on a user record with the
same ordering prefix in in the
B-tree index */
ulint latch_mode, /*!< in: latch mode wished in
restoration */
btr_pcur_t* pcur, /*!< in: cursor whose position
has been stored */
ibool moves_up, /*!< in: TRUE if the cursor moves up
in the index */
mtr_t* mtr) /*!< in: mtr; CAUTION: may commit
mtr temporarily! */
{
ibool success;
success = btr_pcur_restore_position(latch_mode, pcur, mtr);
*same_user_rec = success;
ut_ad(!success || pcur->rel_pos == BTR_PCUR_ON);
#ifdef UNIV_DEBUG
if (pcur->pos_state == BTR_PCUR_IS_POSITIONED_OPTIMISTIC) {
ut_ad(pcur->rel_pos == BTR_PCUR_BEFORE
|| pcur->rel_pos == BTR_PCUR_AFTER);
} else {
ut_ad(pcur->pos_state == BTR_PCUR_IS_POSITIONED);
ut_ad((pcur->rel_pos == BTR_PCUR_ON)
== btr_pcur_is_on_user_rec(pcur));
}
#endif /* UNIV_DEBUG */
/* The position may need be adjusted for rel_pos and moves_up. */
switch (pcur->rel_pos) {
case BTR_PCUR_ON:
if (!success && moves_up) {
next:
btr_pcur_move_to_next(pcur, mtr);
return(TRUE);
}
return(!success);
case BTR_PCUR_AFTER_LAST_IN_TREE:
case BTR_PCUR_BEFORE_FIRST_IN_TREE:
return(TRUE);
case BTR_PCUR_AFTER:
/* positioned to record after pcur->old_rec. */
pcur->pos_state = BTR_PCUR_IS_POSITIONED;
prev:
if (btr_pcur_is_on_user_rec(pcur) && !moves_up) {
btr_pcur_move_to_prev(pcur, mtr);
}
return(TRUE);
case BTR_PCUR_BEFORE:
/* For non optimistic restoration:
The position is now set to the record before pcur->old_rec.
For optimistic restoration:
The position also needs to take the previous search_mode into
consideration. */
switch (pcur->pos_state) {
case BTR_PCUR_IS_POSITIONED_OPTIMISTIC:
pcur->pos_state = BTR_PCUR_IS_POSITIONED;
if (pcur->search_mode == PAGE_CUR_GE) {
/* Positioned during Greater or Equal search
with BTR_PCUR_BEFORE. Optimistic restore to
the same record. If scanning for lower then
we must move to previous record.
This can happen with:
HANDLER READ idx a = (const);
HANDLER READ idx PREV; */
goto prev;
}
return(TRUE);
case BTR_PCUR_IS_POSITIONED:
if (moves_up && btr_pcur_is_on_user_rec(pcur)) {
goto next;
}
return(TRUE);
case BTR_PCUR_WAS_POSITIONED:
case BTR_PCUR_NOT_POSITIONED:
break;
}
}
ut_ad(0);
return(TRUE);
}
/********************************************************************//**
Copies a cached field for MySQL from the fetch cache. */
static
void
row_sel_copy_cached_field_for_mysql(
/*================================*/
byte* buf, /*!< in/out: row buffer */
const byte* cache, /*!< in: cached row */
const mysql_row_templ_t*templ) /*!< in: column template */
{
ulint len;
buf += templ->mysql_col_offset;
cache += templ->mysql_col_offset;
UNIV_MEM_ASSERT_W(buf, templ->mysql_col_len);
if (templ->mysql_type == DATA_MYSQL_TRUE_VARCHAR
&& (templ->type != DATA_INT)) {
/* Check for != DATA_INT to make sure we do
not treat MySQL ENUM or SET as a true VARCHAR!
Find the actual length of the true VARCHAR field. */
row_mysql_read_true_varchar(
&len, cache, templ->mysql_length_bytes);
len += templ->mysql_length_bytes;
UNIV_MEM_INVALID(buf, templ->mysql_col_len);
} else {
len = templ->mysql_col_len;
}
ut_memcpy(buf, cache, len);
}
/** Copy used fields from cached row.
Copy cache record field by field, don't touch fields that
are not covered by current key.
@param[out] buf Where to copy the MySQL row.
@param[in] cached_rec What to copy (in MySQL row format).
@param[in] prebuilt prebuilt struct. */
void
row_sel_copy_cached_fields_for_mysql(
byte* buf,
const byte* cached_rec,
row_prebuilt_t* prebuilt)
{
const mysql_row_templ_t*templ;
ulint i;
for (i = 0; i < prebuilt->n_template; i++) {
templ = prebuilt->mysql_template + i;
/* Skip virtual columns */
if (templ->is_virtual) {
continue;
}
row_sel_copy_cached_field_for_mysql(
buf, cached_rec, templ);
/* Copy NULL bit of the current field from cached_rec
to buf */
if (templ->mysql_null_bit_mask) {
buf[templ->mysql_null_byte_offset]
^= (buf[templ->mysql_null_byte_offset]
^ cached_rec[templ->mysql_null_byte_offset])
& (byte) templ->mysql_null_bit_mask;
}
}
}
/********************************************************************//**
Pops a cached row for MySQL from the fetch cache. */
UNIV_INLINE
void
row_sel_dequeue_cached_row_for_mysql(
/*=================================*/
byte* buf, /*!< in/out: buffer where to copy the
row */
row_prebuilt_t* prebuilt) /*!< in: prebuilt struct */
{
ulint i;
const mysql_row_templ_t*templ;
const byte* cached_rec;
ut_ad(prebuilt->n_fetch_cached > 0);
ut_ad(prebuilt->mysql_prefix_len <= prebuilt->mysql_row_len);
UNIV_MEM_ASSERT_W(buf, prebuilt->mysql_row_len);
cached_rec = prebuilt->fetch_cache[prebuilt->fetch_cache_first];
if (UNIV_UNLIKELY(prebuilt->keep_other_fields_on_keyread)) {
row_sel_copy_cached_fields_for_mysql(buf, cached_rec, prebuilt);
} else if (prebuilt->mysql_prefix_len > 63) {
/* The record is long. Copy it field by field, in case
there are some long VARCHAR column of which only a
small length is being used. */
UNIV_MEM_INVALID(buf, prebuilt->mysql_prefix_len);
/* First copy the NULL bits. */
ut_memcpy(buf, cached_rec, prebuilt->null_bitmap_len);
/* Then copy the requested fields. */
for (i = 0; i < prebuilt->n_template; i++) {
templ = prebuilt->mysql_template + i;
/* Skip virtual columns */
if (templ->is_virtual
&& !(dict_index_has_virtual(prebuilt->index)
&& prebuilt->read_just_key)) {
continue;
}
row_sel_copy_cached_field_for_mysql(
buf, cached_rec, templ);
}
} else {
ut_memcpy(buf, cached_rec, prebuilt->mysql_prefix_len);
}
prebuilt->n_fetch_cached--;
prebuilt->fetch_cache_first++;
if (prebuilt->n_fetch_cached == 0) {
prebuilt->fetch_cache_first = 0;
}
}
/********************************************************************//**
Initialise the prefetch cache. */
UNIV_INLINE
void
row_sel_prefetch_cache_init(
/*========================*/
row_prebuilt_t* prebuilt) /*!< in/out: prebuilt struct */
{
ulint i;
ulint sz;
byte* ptr;
/* Reserve space for the magic number. */
sz = UT_ARR_SIZE(prebuilt->fetch_cache) * (prebuilt->mysql_row_len + 8);
ptr = static_cast<byte*>(ut_malloc_nokey(sz));
for (i = 0; i < UT_ARR_SIZE(prebuilt->fetch_cache); i++) {
/* A user has reported memory corruption in these
buffers in Linux. Put magic numbers there to help
to track a possible bug. */
mach_write_to_4(ptr, ROW_PREBUILT_FETCH_MAGIC_N);
ptr += 4;
prebuilt->fetch_cache[i] = ptr;
ptr += prebuilt->mysql_row_len;
mach_write_to_4(ptr, ROW_PREBUILT_FETCH_MAGIC_N);
ptr += 4;
}
}
/********************************************************************//**
Get the last fetch cache buffer from the queue.
@return pointer to buffer. */
UNIV_INLINE
byte*
row_sel_fetch_last_buf(
/*===================*/
row_prebuilt_t* prebuilt) /*!< in/out: prebuilt struct */
{
ut_ad(!prebuilt->templ_contains_blob);
ut_ad(prebuilt->n_fetch_cached < MYSQL_FETCH_CACHE_SIZE);
if (prebuilt->fetch_cache[0] == NULL) {
/* Allocate memory for the fetch cache */
ut_ad(prebuilt->n_fetch_cached == 0);
row_sel_prefetch_cache_init(prebuilt);
}
ut_ad(prebuilt->fetch_cache_first == 0);
UNIV_MEM_INVALID(prebuilt->fetch_cache[prebuilt->n_fetch_cached],
prebuilt->mysql_row_len);
return(prebuilt->fetch_cache[prebuilt->n_fetch_cached]);
}
/********************************************************************//**
Pushes a row for MySQL to the fetch cache. */
UNIV_INLINE
void
row_sel_enqueue_cache_row_for_mysql(
/*================================*/
byte* mysql_rec, /*!< in/out: MySQL record */
row_prebuilt_t* prebuilt) /*!< in/out: prebuilt struct */
{
/* For non ICP code path the row should already exist in the
next fetch cache slot. */
if (prebuilt->idx_cond != NULL) {
byte* dest = row_sel_fetch_last_buf(prebuilt);
ut_memcpy(dest, mysql_rec, prebuilt->mysql_row_len);
}
++prebuilt->n_fetch_cached;
}
#ifdef BTR_CUR_HASH_ADAPT
/*********************************************************************//**
Tries to do a shortcut to fetch a clustered index record with a unique key,
using the hash index if possible (not always). We assume that the search
mode is PAGE_CUR_GE, it is a consistent read, there is a read view in trx,
btr search latch has been locked in S-mode if AHI is enabled.
@return SEL_FOUND, SEL_EXHAUSTED, SEL_RETRY */
static
ulint
row_sel_try_search_shortcut_for_mysql(
/*==================================*/
const rec_t** out_rec,/*!< out: record if found */
row_prebuilt_t* prebuilt,/*!< in: prebuilt struct */
ulint** offsets,/*!< in/out: for rec_get_offsets(*out_rec) */
mem_heap_t** heap, /*!< in/out: heap for rec_get_offsets() */
mtr_t* mtr) /*!< in: started mtr */
{
dict_index_t* index = prebuilt->index;
const dtuple_t* search_tuple = prebuilt->search_tuple;
btr_pcur_t* pcur = prebuilt->pcur;
trx_t* trx = prebuilt->trx;
const rec_t* rec;
ut_ad(dict_index_is_clust(index));
ut_ad(!prebuilt->templ_contains_blob);
btr_pcur_open_with_no_init(index, search_tuple, PAGE_CUR_GE,
BTR_SEARCH_LEAF, pcur, RW_S_LATCH, mtr);
rec = btr_pcur_get_rec(pcur);
if (!page_rec_is_user_rec(rec)) {
return(SEL_RETRY);
}
/* As the cursor is now placed on a user record after a search with
the mode PAGE_CUR_GE, the up_match field in the cursor tells how many
fields in the user record matched to the search tuple */
if (btr_pcur_get_up_match(pcur) < dtuple_get_n_fields(search_tuple)) {
return(SEL_EXHAUSTED);
}
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
*offsets = rec_get_offsets(rec, index, *offsets, true,
ULINT_UNDEFINED, heap);
if (!lock_clust_rec_cons_read_sees(
rec, index, *offsets, trx_get_read_view(trx))) {
return(SEL_RETRY);
}
if (rec_get_deleted_flag(rec, dict_table_is_comp(index->table))) {
/* In delete-marked records, DB_TRX_ID must
always refer to an existing undo log record. */
ut_ad(row_get_rec_trx_id(rec, index, *offsets));
return(SEL_EXHAUSTED);
}
*out_rec = rec;
return(SEL_FOUND);
}
#endif /* BTR_CUR_HASH_ADAPT */
/*********************************************************************//**
Check a pushed-down index condition.
@return ICP_NO_MATCH, ICP_MATCH, or ICP_OUT_OF_RANGE */
static
ICP_RESULT
row_search_idx_cond_check(
/*======================*/
byte* mysql_rec, /*!< out: record
in MySQL format (invalid unless
prebuilt->idx_cond!=NULL and
we return ICP_MATCH) */
row_prebuilt_t* prebuilt, /*!< in/out: prebuilt struct
for the table handle */
const rec_t* rec, /*!< in: InnoDB record */
const ulint* offsets) /*!< in: rec_get_offsets() */
{
ICP_RESULT result;
ulint i;
ut_ad(rec_offs_validate(rec, prebuilt->index, offsets));
if (!prebuilt->idx_cond) {
return(ICP_MATCH);
}
MONITOR_INC(MONITOR_ICP_ATTEMPTS);
/* Convert to MySQL format those fields that are needed for
evaluating the index condition. */
if (UNIV_LIKELY_NULL(prebuilt->blob_heap)) {
mem_heap_empty(prebuilt->blob_heap);
}
for (i = 0; i < prebuilt->idx_cond_n_cols; i++) {
const mysql_row_templ_t*templ = &prebuilt->mysql_template[i];
/* Skip virtual columns */
if (templ->is_virtual) {
continue;
}
if (!row_sel_store_mysql_field(mysql_rec, prebuilt,
rec, prebuilt->index, offsets,
templ->icp_rec_field_no,
templ)) {
return(ICP_NO_MATCH);
}
}
/* We assume that the index conditions on
case-insensitive columns are case-insensitive. The
case of such columns may be wrong in a secondary
index, if the case of the column has been updated in
the past, or a record has been deleted and a record
inserted in a different case. */
result = innobase_index_cond(prebuilt->idx_cond);
switch (result) {
case ICP_MATCH:
/* Convert the remaining fields to MySQL format.
If this is a secondary index record, we must defer
this until we have fetched the clustered index record. */
if (!prebuilt->need_to_access_clustered
|| dict_index_is_clust(prebuilt->index)) {
if (!row_sel_store_mysql_rec(
mysql_rec, prebuilt, rec, NULL, false,
prebuilt->index, offsets)) {
ut_ad(dict_index_is_clust(prebuilt->index));
return(ICP_NO_MATCH);
}
}
MONITOR_INC(MONITOR_ICP_MATCH);
return(result);
case ICP_NO_MATCH:
MONITOR_INC(MONITOR_ICP_NO_MATCH);
return(result);
case ICP_OUT_OF_RANGE:
MONITOR_INC(MONITOR_ICP_OUT_OF_RANGE);
return(result);
case ICP_ERROR:
case ICP_ABORTED_BY_USER:
return(result);
}
ut_error;
return(result);
}
/** Extract virtual column data from a virtual index record and fill a dtuple
@param[in] rec the virtual (secondary) index record
@param[in] index the virtual index
@param[in,out] vrow the dtuple where data extract to
@param[in] heap memory heap to allocate memory
*/
static
void
row_sel_fill_vrow(
const rec_t* rec,
dict_index_t* index,
dtuple_t** vrow,
mem_heap_t* heap)
{
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
rec_offs_init(offsets_);
ut_ad(!(*vrow));
ut_ad(page_rec_is_leaf(rec));
offsets = rec_get_offsets(rec, index, offsets, true,
ULINT_UNDEFINED, &heap);
*vrow = dtuple_create_with_vcol(
heap, 0, dict_table_get_n_v_cols(index->table));
/* Initialize all virtual row's mtype to DATA_MISSING */
dtuple_init_v_fld(*vrow);
for (ulint i = 0; i < dict_index_get_n_fields(index); i++) {
const dict_field_t* field;
const dict_col_t* col;
field = dict_index_get_nth_field(index, i);
col = dict_field_get_col(field);
if (dict_col_is_virtual(col)) {
const byte* data;
ulint len;
data = rec_get_nth_field(rec, offsets, i, &len);
const dict_v_col_t* vcol = reinterpret_cast<
const dict_v_col_t*>(col);
dfield_t* dfield = dtuple_get_nth_v_field(
*vrow, vcol->v_pos);
dfield_set_data(dfield, data, len);
dict_col_copy_type(col, dfield_get_type(dfield));
}
}
}
/** Return the record field length in characters.
@param[in] col table column of the field
@param[in] field_no field number
@param[in] rec physical record
@param[in] offsets field offsets in the physical record
@return field length in characters. */
static
size_t
rec_field_len_in_chars(
const dict_col_t* col,
const ulint field_no,
const rec_t* rec,
const ulint* offsets)
{
const ulint cset = dtype_get_charset_coll(col->prtype);
const CHARSET_INFO* cs = all_charsets[cset];
ulint rec_field_len;
const char* rec_field = reinterpret_cast<const char *>(
rec_get_nth_field(
rec, offsets, field_no, &rec_field_len));
if (UNIV_UNLIKELY(!cs)) {
ib::warn() << "Missing collation " << cset;
return SIZE_T_MAX;
}
return(cs->cset->numchars(cs, rec_field, rec_field + rec_field_len));
}
/** Avoid the clustered index lookup if all the following conditions
are true:
1) all columns are in secondary index
2) all values for columns that are prefix-only indexes are shorter
than the prefix size. This optimization can avoid many IOs for certain schemas.
@return true, to avoid clustered index lookup. */
static
bool row_search_with_covering_prefix(
row_prebuilt_t* prebuilt,
const rec_t* rec,
const ulint* offsets)
{
const dict_index_t* index = prebuilt->index;
ut_ad(!dict_index_is_clust(index));
if (!srv_prefix_index_cluster_optimization) {
return false;
}
/** Optimization only applicable if there the number of secondary index
fields are greater than or equal to number of clustered index fields. */
if (prebuilt->n_template > index->n_fields) {
return false;
}
for (ulint i = 0; i < prebuilt->n_template; i++) {
mysql_row_templ_t* templ = prebuilt->mysql_template + i;
ulint j = templ->rec_prefix_field_no;
/** Condition (1) : is the field in the index. */
if (j == ULINT_UNDEFINED) {
return false;
}
/** Condition (2): If this is a prefix index then
row's value size shorter than prefix length. */
if (!templ->rec_field_is_prefix) {
continue;
}
ulint rec_size = rec_offs_nth_size(offsets, j);
const dict_field_t* field = dict_index_get_nth_field(index, j);
ulint max_chars = field->prefix_len / templ->mbmaxlen;
ut_a(field->prefix_len > 0);
if (rec_size < max_chars) {
/* Record in bytes shorter than the index
prefix length in char. */
continue;
}
if (rec_size * templ->mbminlen >= field->prefix_len) {
/* Shortest representation string by the
byte length of the record is longer than the
maximum possible index prefix. */
return false;
}
size_t num_chars = rec_field_len_in_chars(
field->col, j, rec, offsets);
if (num_chars >= max_chars) {
/* No of chars to store the record exceeds
the index prefix character length. */
return false;
}
}
/* If prefix index optimization condition satisfied then
for all columns above, use rec_prefix_field_no instead of
rec_field_no, and skip the clustered lookup below. */
for (ulint i = 0; i < prebuilt->n_template; i++) {
mysql_row_templ_t* templ = prebuilt->mysql_template + i;
templ->rec_field_no = templ->rec_prefix_field_no;
ut_a(templ->rec_field_no != ULINT_UNDEFINED);
}
srv_stats.n_sec_rec_cluster_reads_avoided.inc();
return true;
}
/** Searches for rows in the database using cursor.
Function is mainly used for tables that are shared across connections and
so it employs technique that can help re-construct the rows that
transaction is suppose to see.
It also has optimization such as pre-caching the rows, using AHI, etc.
@param[out] buf buffer for the fetched row in MySQL format
@param[in] mode search mode PAGE_CUR_L
@param[in,out] prebuilt prebuilt struct for the table handler;
this contains the info to search_tuple,
index; if search tuple contains 0 field then
we position the cursor at start or the end of
index, depending on 'mode'
@param[in] match_mode 0 or ROW_SEL_EXACT or ROW_SEL_EXACT_PREFIX
@param[in] direction 0 or ROW_SEL_NEXT or ROW_SEL_PREV;
Note: if this is != 0, then prebuilt must has a
pcur with stored position! In opening of a
cursor 'direction' should be 0.
@return DB_SUCCESS or error code */
dberr_t
row_search_mvcc(
byte* buf,
page_cur_mode_t mode,
row_prebuilt_t* prebuilt,
ulint match_mode,
ulint direction)
{
DBUG_ENTER("row_search_mvcc");
dict_index_t* index = prebuilt->index;
ibool comp = dict_table_is_comp(index->table);
const dtuple_t* search_tuple = prebuilt->search_tuple;
btr_pcur_t* pcur = prebuilt->pcur;
trx_t* trx = prebuilt->trx;
dict_index_t* clust_index;
que_thr_t* thr;
const rec_t* rec;
dtuple_t* vrow = NULL;
const rec_t* result_rec = NULL;
const rec_t* clust_rec;
dberr_t err = DB_SUCCESS;
ibool unique_search = FALSE;
ibool mtr_has_extra_clust_latch = FALSE;
ibool moves_up = FALSE;
ibool set_also_gap_locks = TRUE;
/* if the query is a plain locking SELECT, and the isolation level
is <= TRX_ISO_READ_COMMITTED, then this is set to FALSE */
ibool did_semi_consistent_read = FALSE;
/* if the returned record was locked and we did a semi-consistent
read (fetch the newest committed version), then this is set to
TRUE */
ulint next_offs;
ibool same_user_rec;
mtr_t mtr;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
ibool table_lock_waited = FALSE;
byte* next_buf = 0;
bool spatial_search = false;
rec_offs_init(offsets_);
ut_ad(index && pcur && search_tuple);
ut_a(prebuilt->magic_n == ROW_PREBUILT_ALLOCATED);
ut_a(prebuilt->magic_n2 == ROW_PREBUILT_ALLOCATED);
/* We don't support FTS queries from the HANDLER interfaces, because
we implemented FTS as reversed inverted index with auxiliary tables.
So anything related to traditional index query would not apply to
it. */
if (prebuilt->index->type & DICT_FTS) {
DBUG_RETURN(DB_END_OF_INDEX);
}
ut_ad(!sync_check_iterate(sync_check()));
if (dict_table_is_discarded(prebuilt->table)) {
DBUG_RETURN(DB_TABLESPACE_DELETED);
} else if (!prebuilt->table->is_readable()) {
DBUG_RETURN(fil_space_get(prebuilt->table->space)
? DB_DECRYPTION_FAILED
: DB_TABLESPACE_NOT_FOUND);
} else if (!prebuilt->index_usable) {
DBUG_RETURN(DB_MISSING_HISTORY);
} else if (prebuilt->index->is_corrupted()) {
DBUG_RETURN(DB_CORRUPTION);
}
/* We need to get the virtual column values stored in secondary
index key, if this is covered index scan or virtual key read is
requested. */
bool need_vrow = dict_index_has_virtual(prebuilt->index)
&& (prebuilt->read_just_key
|| prebuilt->m_read_virtual_key);
/* Reset the new record lock info if srv_locks_unsafe_for_binlog
is set or session is using a READ COMMITED isolation level. Then
we are able to remove the record locks set here on an individual
row. */
prebuilt->new_rec_locks = 0;
/*-------------------------------------------------------------*/
/* PHASE 1: Try to pop the row from the prefetch cache */
if (UNIV_UNLIKELY(direction == 0)) {
trx->op_info = "starting index read";
prebuilt->n_rows_fetched = 0;
prebuilt->n_fetch_cached = 0;
prebuilt->fetch_cache_first = 0;
if (prebuilt->sel_graph == NULL) {
/* Build a dummy select query graph */
row_prebuild_sel_graph(prebuilt);
}
} else {
trx->op_info = "fetching rows";
if (prebuilt->n_rows_fetched == 0) {
prebuilt->fetch_direction = direction;
}
if (UNIV_UNLIKELY(direction != prebuilt->fetch_direction)) {
if (UNIV_UNLIKELY(prebuilt->n_fetch_cached > 0)) {
ut_error;
/* TODO: scrollable cursor: restore cursor to
the place of the latest returned row,
or better: prevent caching for a scroll
cursor! */
}
prebuilt->n_rows_fetched = 0;
prebuilt->n_fetch_cached = 0;
prebuilt->fetch_cache_first = 0;
} else if (UNIV_LIKELY(prebuilt->n_fetch_cached > 0)) {
row_sel_dequeue_cached_row_for_mysql(buf, prebuilt);
prebuilt->n_rows_fetched++;
err = DB_SUCCESS;
goto func_exit;
}
if (prebuilt->fetch_cache_first > 0
&& prebuilt->fetch_cache_first < MYSQL_FETCH_CACHE_SIZE) {
/* The previous returned row was popped from the fetch
cache, but the cache was not full at the time of the
popping: no more rows can exist in the result set */
err = DB_RECORD_NOT_FOUND;
goto func_exit;
}
prebuilt->n_rows_fetched++;
if (prebuilt->n_rows_fetched > 1000000000) {
/* Prevent wrap-over */
prebuilt->n_rows_fetched = 500000000;
}
mode = pcur->search_mode;
}
/* In a search where at most one record in the index may match, we
can use a LOCK_REC_NOT_GAP type record lock when locking a
non-delete-marked matching record.
Note that in a unique secondary index there may be different
delete-marked versions of a record where only the primary key
values differ: thus in a secondary index we must use next-key
locks when locking delete-marked records. */
if (match_mode == ROW_SEL_EXACT
&& dict_index_is_unique(index)
&& dtuple_get_n_fields(search_tuple)
== dict_index_get_n_unique(index)
&& (dict_index_is_clust(index)
|| !dtuple_contains_null(search_tuple))) {
/* Note above that a UNIQUE secondary index can contain many
rows with the same key value if one of the columns is the SQL
null. A clustered index under MySQL can never contain null
columns because we demand that all the columns in primary key
are non-null. */
unique_search = TRUE;
/* Even if the condition is unique, MySQL seems to try to
retrieve also a second row if a primary key contains more than
1 column. Return immediately if this is not a HANDLER
command. */
if (UNIV_UNLIKELY(direction != 0
&& !prebuilt->used_in_HANDLER)) {
err = DB_RECORD_NOT_FOUND;
goto func_exit;
}
}
/* We don't support sequencial scan for Rtree index, because it
is no meaning to do so. */
if (dict_index_is_spatial(index)
&& !RTREE_SEARCH_MODE(mode)) {
err = DB_END_OF_INDEX;
goto func_exit;
}
mtr.start();
#ifdef BTR_CUR_HASH_ADAPT
/*-------------------------------------------------------------*/
/* PHASE 2: Try fast adaptive hash index search if possible */
/* Next test if this is the special case where we can use the fast
adaptive hash index to try the search. Since we must release the
search system latch when we retrieve an externally stored field, we
cannot use the adaptive hash index in a search in the case the row
may be long and there may be externally stored fields */
if (UNIV_UNLIKELY(direction == 0)
&& unique_search
&& btr_search_enabled
&& dict_index_is_clust(index)
&& !prebuilt->templ_contains_blob
&& !prebuilt->used_in_HANDLER
&& (prebuilt->mysql_row_len < UNIV_PAGE_SIZE / 8)) {
mode = PAGE_CUR_GE;
if (trx->mysql_n_tables_locked == 0
&& prebuilt->select_lock_type == LOCK_NONE
&& trx->isolation_level > TRX_ISO_READ_UNCOMMITTED
&& MVCC::is_view_active(trx->read_view)) {
/* This is a SELECT query done as a consistent read,
and the read view has already been allocated:
let us try a search shortcut through the hash
index.
NOTE that we must also test that
mysql_n_tables_locked == 0, because this might
also be INSERT INTO ... SELECT ... or
CREATE TABLE ... SELECT ... . Our algorithm is
NOT prepared to inserts interleaved with the SELECT,
and if we try that, we can deadlock on the adaptive
hash index semaphore! */
rw_lock_s_lock(btr_get_search_latch(index));
switch (row_sel_try_search_shortcut_for_mysql(
&rec, prebuilt, &offsets, &heap,
&mtr)) {
case SEL_FOUND:
/* At this point, rec is protected by
a page latch that was acquired by
row_sel_try_search_shortcut_for_mysql().
The latch will not be released until
mtr.commit(). */
ut_ad(!rec_get_deleted_flag(rec, comp));
if (prebuilt->idx_cond) {
switch (row_search_idx_cond_check(
buf, prebuilt,
rec, offsets)) {
case ICP_NO_MATCH:
case ICP_OUT_OF_RANGE:
case ICP_ABORTED_BY_USER:
case ICP_ERROR:
goto shortcut_mismatch;
case ICP_MATCH:
goto shortcut_match;
}
}
if (!row_sel_store_mysql_rec(
buf, prebuilt,
rec, NULL, false, index,
offsets)) {
/* Only fresh inserts may contain
incomplete externally stored
columns. Pretend that such
records do not exist. Such
records may only be accessed
at the READ UNCOMMITTED
isolation level or when
rolling back a recovered
transaction. Rollback happens
at a lower level, not here. */
/* Proceed as in case SEL_RETRY. */
break;
}
shortcut_match:
mtr.commit();
/* NOTE that we do NOT store the cursor
position */
err = DB_SUCCESS;
rw_lock_s_unlock(btr_get_search_latch(index));
goto func_exit;
case SEL_EXHAUSTED:
shortcut_mismatch:
mtr.commit();
err = DB_RECORD_NOT_FOUND;
rw_lock_s_unlock(btr_get_search_latch(index));
/* NOTE that we do NOT store the cursor
position */
goto func_exit;
case SEL_RETRY:
break;
default:
ut_ad(0);
}
mtr.commit();
mtr.start();
rw_lock_s_unlock(btr_get_search_latch(index));
}
}
#endif /* BTR_CUR_HASH_ADAPT */
/*-------------------------------------------------------------*/
/* PHASE 3: Open or restore index cursor position */
spatial_search = dict_index_is_spatial(index)
&& mode >= PAGE_CUR_CONTAIN;
/* The state of a running trx can only be changed by the
thread that is currently serving the transaction. Because we
are that thread, we can read trx->state without holding any
mutex. */
ut_ad(prebuilt->sql_stat_start || trx->state == TRX_STATE_ACTIVE);
ut_ad(!trx_is_started(trx) || trx->state == TRX_STATE_ACTIVE);
ut_ad(prebuilt->sql_stat_start
|| prebuilt->select_lock_type != LOCK_NONE
|| MVCC::is_view_active(trx->read_view)
|| srv_read_only_mode);
trx_start_if_not_started(trx, false);
if (trx->isolation_level <= TRX_ISO_READ_COMMITTED
&& prebuilt->select_lock_type != LOCK_NONE
&& trx->mysql_thd != NULL
&& thd_is_select(trx->mysql_thd)) {
/* It is a plain locking SELECT and the isolation
level is low: do not lock gaps */
set_also_gap_locks = FALSE;
}
/* Note that if the search mode was GE or G, then the cursor
naturally moves upward (in fetch next) in alphabetical order,
otherwise downward */
if (UNIV_UNLIKELY(direction == 0)) {
if (mode == PAGE_CUR_GE || mode == PAGE_CUR_G
|| mode >= PAGE_CUR_CONTAIN) {
moves_up = TRUE;
}
} else if (direction == ROW_SEL_NEXT) {
moves_up = TRUE;
}
thr = que_fork_get_first_thr(prebuilt->sel_graph);
que_thr_move_to_run_state_for_mysql(thr, trx);
clust_index = dict_table_get_first_index(index->table);
/* Do some start-of-statement preparations */
if (!prebuilt->sql_stat_start) {
/* No need to set an intention lock or assign a read view */
if (!MVCC::is_view_active(trx->read_view)
&& !srv_read_only_mode
&& prebuilt->select_lock_type == LOCK_NONE) {
ib::error() << "MySQL is trying to perform a"
" consistent read but the read view is not"
" assigned!";
trx_print(stderr, trx, 600);
fputc('\n', stderr);
ut_error;
}
} else if (prebuilt->select_lock_type == LOCK_NONE) {
/* This is a consistent read */
/* Assign a read view for the query */
if (!srv_read_only_mode) {
trx_assign_read_view(trx);
}
prebuilt->sql_stat_start = FALSE;
} else {
wait_table_again:
err = lock_table(0, index->table,
prebuilt->select_lock_type == LOCK_S
? LOCK_IS : LOCK_IX, thr);
if (err != DB_SUCCESS) {
table_lock_waited = TRUE;
goto lock_table_wait;
}
prebuilt->sql_stat_start = FALSE;
}
/* Open or restore index cursor position */
if (UNIV_LIKELY(direction != 0)) {
if (spatial_search) {
/* R-Tree access does not need to do
cursor position and resposition */
goto next_rec;
}
ibool need_to_process = sel_restore_position_for_mysql(
&same_user_rec, BTR_SEARCH_LEAF,
pcur, moves_up, &mtr);
if (UNIV_UNLIKELY(need_to_process)) {
if (UNIV_UNLIKELY(prebuilt->row_read_type
== ROW_READ_DID_SEMI_CONSISTENT)) {
/* We did a semi-consistent read,
but the record was removed in
the meantime. */
prebuilt->row_read_type
= ROW_READ_TRY_SEMI_CONSISTENT;
}
} else if (UNIV_LIKELY(prebuilt->row_read_type
!= ROW_READ_DID_SEMI_CONSISTENT)) {
/* The cursor was positioned on the record
that we returned previously. If we need
to repeat a semi-consistent read as a
pessimistic locking read, the record
cannot be skipped. */
goto next_rec;
}
} else if (dtuple_get_n_fields(search_tuple) > 0) {
pcur->btr_cur.thr = thr;
if (dict_index_is_spatial(index)) {
bool need_pred_lock;
need_pred_lock = (set_also_gap_locks
&& !(srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type
!= LOCK_NONE);
if (!prebuilt->rtr_info) {
prebuilt->rtr_info = rtr_create_rtr_info(
need_pred_lock, true,
btr_pcur_get_btr_cur(pcur), index);
prebuilt->rtr_info->search_tuple = search_tuple;
prebuilt->rtr_info->search_mode = mode;
rtr_info_update_btr(btr_pcur_get_btr_cur(pcur),
prebuilt->rtr_info);
} else {
rtr_info_reinit_in_cursor(
btr_pcur_get_btr_cur(pcur),
index, need_pred_lock);
prebuilt->rtr_info->search_tuple = search_tuple;
prebuilt->rtr_info->search_mode = mode;
}
}
err = btr_pcur_open_with_no_init(index, search_tuple, mode,
BTR_SEARCH_LEAF,
pcur, 0, &mtr);
if (err != DB_SUCCESS) {
rec = NULL;
goto lock_wait_or_error;
}
pcur->trx_if_known = trx;
rec = btr_pcur_get_rec(pcur);
ut_ad(page_rec_is_leaf(rec));
if (!moves_up
&& !page_rec_is_supremum(rec)
&& set_also_gap_locks
&& !(srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE
&& !dict_index_is_spatial(index)) {
/* Try to place a gap lock on the next index record
to prevent phantoms in ORDER BY ... DESC queries */
const rec_t* next_rec = page_rec_get_next_const(rec);
offsets = rec_get_offsets(next_rec, index, offsets,
true,
ULINT_UNDEFINED, &heap);
err = sel_set_rec_lock(pcur,
next_rec, index, offsets,
prebuilt->select_lock_type,
LOCK_GAP, thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
/* fall through */
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
} else if (mode == PAGE_CUR_G || mode == PAGE_CUR_L) {
err = btr_pcur_open_at_index_side(
mode == PAGE_CUR_G, index, BTR_SEARCH_LEAF,
pcur, false, 0, &mtr);
if (err != DB_SUCCESS) {
if (err == DB_DECRYPTION_FAILED) {
ib_push_warning(trx->mysql_thd,
DB_DECRYPTION_FAILED,
"Table %s is encrypted but encryption service or"
" used key_id is not available. "
" Can't continue reading table.",
prebuilt->table->name.m_name);
index->table->file_unreadable = true;
}
rec = NULL;
goto lock_wait_or_error;
}
}
rec_loop:
DEBUG_SYNC_C("row_search_rec_loop");
if (trx_is_interrupted(trx)) {
if (!spatial_search) {
btr_pcur_store_position(pcur, &mtr);
}
err = DB_INTERRUPTED;
goto normal_return;
}
/*-------------------------------------------------------------*/
/* PHASE 4: Look for matching records in a loop */
rec = btr_pcur_get_rec(pcur);
if (!index->table->is_readable()) {
err = DB_DECRYPTION_FAILED;
goto lock_wait_or_error;
}
ut_ad(!!page_rec_is_comp(rec) == comp);
ut_ad(page_rec_is_leaf(rec));
if (page_rec_is_infimum(rec)) {
/* The infimum record on a page cannot be in the result set,
and neither can a record lock be placed on it: we skip such
a record. */
goto next_rec;
}
if (page_rec_is_supremum(rec)) {
if (set_also_gap_locks
&& !(srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE
&& !dict_index_is_spatial(index)) {
/* Try to place a lock on the index record */
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using a READ COMMITTED or lower isolation
level we do not lock gaps. Supremum record is really
a gap and therefore we do not set locks there. */
offsets = rec_get_offsets(rec, index, offsets, true,
ULINT_UNDEFINED, &heap);
err = sel_set_rec_lock(pcur,
rec, index, offsets,
prebuilt->select_lock_type,
LOCK_ORDINARY, thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
err = DB_SUCCESS;
/* fall through */
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
/* A page supremum record cannot be in the result set: skip
it now that we have placed a possible lock on it */
goto next_rec;
}
/*-------------------------------------------------------------*/
/* Do sanity checks in case our cursor has bumped into page
corruption */
if (comp) {
next_offs = rec_get_next_offs(rec, TRUE);
if (UNIV_UNLIKELY(next_offs < PAGE_NEW_SUPREMUM)) {
goto wrong_offs;
}
} else {
next_offs = rec_get_next_offs(rec, FALSE);
if (UNIV_UNLIKELY(next_offs < PAGE_OLD_SUPREMUM)) {
goto wrong_offs;
}
}
if (UNIV_UNLIKELY(next_offs >= UNIV_PAGE_SIZE - PAGE_DIR)) {
wrong_offs:
if (srv_force_recovery == 0 || moves_up == FALSE) {
ib::error() << "Rec address "
<< static_cast<const void*>(rec)
<< ", buf block fix count "
<< btr_cur_get_block(
btr_pcur_get_btr_cur(pcur))->page
.buf_fix_count;
ib::error() << "Index corruption: rec offs "
<< page_offset(rec) << " next offs "
<< next_offs << ", page no "
<< page_get_page_no(page_align(rec))
<< ", index " << index->name
<< " of table " << index->table->name
<< ". Run CHECK TABLE. You may need to"
" restore from a backup, or dump + drop +"
" reimport the table.";
ut_ad(0);
err = DB_CORRUPTION;
goto lock_wait_or_error;
} else {
/* The user may be dumping a corrupt table. Jump
over the corruption to recover as much as possible. */
ib::info() << "Index corruption: rec offs "
<< page_offset(rec) << " next offs "
<< next_offs << ", page no "
<< page_get_page_no(page_align(rec))
<< ", index " << index->name
<< " of table " << index->table->name
<< ". We try to skip the rest of the page.";
page_cur_set_after_last(btr_pcur_get_block(pcur),
btr_pcur_get_page_cur(pcur));
pcur->old_stored = false;
goto next_rec;
}
}
/*-------------------------------------------------------------*/
/* Calculate the 'offsets' associated with 'rec' */
ut_ad(fil_page_index_page_check(btr_pcur_get_page(pcur)));
ut_ad(btr_page_get_index_id(btr_pcur_get_page(pcur)) == index->id);
offsets = rec_get_offsets(rec, index, offsets, true,
ULINT_UNDEFINED, &heap);
if (UNIV_UNLIKELY(srv_force_recovery > 0)) {
if (!rec_validate(rec, offsets)
|| !btr_index_rec_validate(rec, index, FALSE)) {
ib::error() << "Index corruption: rec offs "
<< page_offset(rec) << " next offs "
<< next_offs << ", page no "
<< page_get_page_no(page_align(rec))
<< ", index " << index->name
<< " of table " << index->table->name
<< ". We try to skip the record.";
goto next_rec;
}
}
/* Note that we cannot trust the up_match value in the cursor at this
place because we can arrive here after moving the cursor! Thus
we have to recompare rec and search_tuple to determine if they
match enough. */
if (match_mode == ROW_SEL_EXACT) {
/* Test if the index record matches completely to search_tuple
in prebuilt: if not, then we return with DB_RECORD_NOT_FOUND */
/* fputs("Comparing rec and search tuple\n", stderr); */
if (0 != cmp_dtuple_rec(search_tuple, rec, offsets)) {
if (set_also_gap_locks
&& !(srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE
&& !dict_index_is_spatial(index)) {
/* Try to place a gap lock on the index
record only if innodb_locks_unsafe_for_binlog
option is not set or this session is not
using a READ COMMITTED or lower isolation level. */
err = sel_set_rec_lock(
pcur,
rec, index, offsets,
prebuilt->select_lock_type, LOCK_GAP,
thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
btr_pcur_store_position(pcur, &mtr);
/* The found record was not a match, but may be used
as NEXT record (index_next). Set the relative position
to BTR_PCUR_BEFORE, to reflect that the position of
the persistent cursor is before the found/stored row
(pcur->old_rec). */
ut_ad(pcur->rel_pos == BTR_PCUR_ON);
pcur->rel_pos = BTR_PCUR_BEFORE;
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
} else if (match_mode == ROW_SEL_EXACT_PREFIX) {
if (!cmp_dtuple_is_prefix_of_rec(search_tuple, rec, offsets)) {
if (set_also_gap_locks
&& !(srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE
&& !dict_index_is_spatial(index)) {
/* Try to place a gap lock on the index
record only if innodb_locks_unsafe_for_binlog
option is not set or this session is not
using a READ COMMITTED or lower isolation level. */
err = sel_set_rec_lock(
pcur,
rec, index, offsets,
prebuilt->select_lock_type, LOCK_GAP,
thr, &mtr);
switch (err) {
case DB_SUCCESS_LOCKED_REC:
case DB_SUCCESS:
break;
default:
goto lock_wait_or_error;
}
}
btr_pcur_store_position(pcur, &mtr);
/* The found record was not a match, but may be used
as NEXT record (index_next). Set the relative position
to BTR_PCUR_BEFORE, to reflect that the position of
the persistent cursor is before the found/stored row
(pcur->old_rec). */
ut_ad(pcur->rel_pos == BTR_PCUR_ON);
pcur->rel_pos = BTR_PCUR_BEFORE;
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
}
/* We are ready to look at a possible new index entry in the result
set: the cursor is now placed on a user record */
if (prebuilt->select_lock_type != LOCK_NONE) {
/* Try to place a lock on the index record; note that delete
marked records are a special case in a unique search. If there
is a non-delete marked record, then it is enough to lock its
existence with LOCK_REC_NOT_GAP. */
/* If innodb_locks_unsafe_for_binlog option is used
or this session is using a READ COMMITED isolation
level we lock only the record, i.e., next-key locking is
not used. */
ulint lock_type;
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED) {
/* At READ COMMITTED or READ UNCOMMITTED
isolation levels, do not lock committed
delete-marked records. */
if (!rec_get_deleted_flag(rec, comp)) {
goto no_gap_lock;
}
/* At most one transaction can be active
for temporary table. */
if (dict_table_is_temporary(clust_index->table)) {
goto no_gap_lock;
}
if (index == clust_index) {
trx_id_t trx_id = row_get_rec_trx_id(
rec, index, offsets);
/* In delete-marked records, DB_TRX_ID must
always refer to an existing undo log record. */
ut_ad(trx_id);
if (!trx_rw_is_active(trx_id, NULL, false)) {
/* The clustered index record
was delete-marked in a committed
transaction. Ignore the record. */
goto locks_ok_del_marked;
}
} else if (trx_t* trx = row_vers_impl_x_locked(
rec, index, offsets)) {
/* The record belongs to an active
transaction. We must acquire a lock. */
trx_release_reference(trx);
} else {
/* The secondary index record does not
point to a delete-marked clustered index
record that belongs to an active transaction.
Ignore the secondary index record, because
it is not locked. */
goto next_rec;
}
goto no_gap_lock;
}
if (!set_also_gap_locks
|| (unique_search && !rec_get_deleted_flag(rec, comp))
|| dict_index_is_spatial(index)) {
goto no_gap_lock;
} else {
lock_type = LOCK_ORDINARY;
}
/* If we are doing a 'greater or equal than a primary key
value' search from a clustered index, and we find a record
that has that exact primary key value, then there is no need
to lock the gap before the record, because no insert in the
gap can be in our search range. That is, no phantom row can
appear that way.
An example: if col1 is the primary key, the search is WHERE
col1 >= 100, and we find a record where col1 = 100, then no
need to lock the gap before that record. */
if (index == clust_index
&& mode == PAGE_CUR_GE
&& direction == 0
&& dtuple_get_n_fields_cmp(search_tuple)
== dict_index_get_n_unique(index)
&& 0 == cmp_dtuple_rec(search_tuple, rec, offsets)) {
no_gap_lock:
lock_type = LOCK_REC_NOT_GAP;
}
err = sel_set_rec_lock(pcur,
rec, index, offsets,
prebuilt->select_lock_type,
lock_type, thr, &mtr);
switch (err) {
const rec_t* old_vers;
case DB_SUCCESS_LOCKED_REC:
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED) {
/* Note that a record of
prebuilt->index was locked. */
prebuilt->new_rec_locks = 1;
}
err = DB_SUCCESS;
/* fall through */
case DB_SUCCESS:
break;
case DB_LOCK_WAIT:
/* Lock wait for R-tree should already
be handled in sel_set_rtr_rec_lock() */
ut_ad(!dict_index_is_spatial(index));
/* Never unlock rows that were part of a conflict. */
prebuilt->new_rec_locks = 0;
if (UNIV_LIKELY(prebuilt->row_read_type
!= ROW_READ_TRY_SEMI_CONSISTENT)
|| unique_search
|| index != clust_index) {
goto lock_wait_or_error;
}
/* The following call returns 'offsets'
associated with 'old_vers' */
row_sel_build_committed_vers_for_mysql(
clust_index, prebuilt, rec,
&offsets, &heap, &old_vers, need_vrow ? &vrow : NULL,
&mtr);
/* Check whether it was a deadlock or not, if not
a deadlock and the transaction had to wait then
release the lock it is waiting on. */
err = lock_trx_handle_wait(trx);
switch (err) {
case DB_SUCCESS:
/* The lock was granted while we were
searching for the last committed version.
Do a normal locking read. */
offsets = rec_get_offsets(
rec, index, offsets, true,
ULINT_UNDEFINED, &heap);
goto locks_ok;
case DB_DEADLOCK:
goto lock_wait_or_error;
case DB_LOCK_WAIT:
ut_ad(!dict_index_is_spatial(index));
err = DB_SUCCESS;
break;
default:
ut_error;
}
if (old_vers == NULL) {
/* The row was not yet committed */
goto next_rec;
}
did_semi_consistent_read = TRUE;
rec = old_vers;
break;
case DB_RECORD_NOT_FOUND:
if (dict_index_is_spatial(index)) {
goto next_rec;
} else {
goto lock_wait_or_error;
}
default:
goto lock_wait_or_error;
}
} else {
/* This is a non-locking consistent read: if necessary, fetch
a previous version of the record */
if (trx->isolation_level == TRX_ISO_READ_UNCOMMITTED) {
/* Do nothing: we let a non-locking SELECT read the
latest version of the record */
} else if (index == clust_index) {
/* Fetch a previous version of the row if the current
one is not visible in the snapshot; if we have a very
high force recovery level set, we try to avoid crashes
by skipping this lookup */
if (srv_force_recovery < 5
&& !lock_clust_rec_cons_read_sees(
rec, index, offsets,
trx_get_read_view(trx))) {
rec_t* old_vers;
/* The following call returns 'offsets'
associated with 'old_vers' */
err = row_sel_build_prev_vers_for_mysql(
trx->read_view, clust_index,
prebuilt, rec, &offsets, &heap,
&old_vers, need_vrow ? &vrow : NULL,
&mtr);
if (err != DB_SUCCESS) {
goto lock_wait_or_error;
}
if (old_vers == NULL) {
/* The row did not exist yet in
the read view */
goto next_rec;
}
rec = old_vers;
}
} else {
/* We are looking into a non-clustered index,
and to get the right version of the record we
have to look also into the clustered index: this
is necessary, because we can only get the undo
information via the clustered index record. */
ut_ad(!dict_index_is_clust(index));
if (!srv_read_only_mode
&& !lock_sec_rec_cons_read_sees(
rec, index, trx->read_view)) {
/* We should look at the clustered index.
However, as this is a non-locking read,
we can skip the clustered index lookup if
the condition does not match the secondary
index entry. */
switch (row_search_idx_cond_check(
buf, prebuilt, rec, offsets)) {
case ICP_NO_MATCH:
goto next_rec;
case ICP_OUT_OF_RANGE:
case ICP_ABORTED_BY_USER:
case ICP_ERROR:
err = DB_RECORD_NOT_FOUND;
goto idx_cond_failed;
case ICP_MATCH:
goto requires_clust_rec;
}
ut_error;
}
}
}
locks_ok:
/* NOTE that at this point rec can be an old version of a clustered
index record built for a consistent read. We cannot assume after this
point that rec is on a buffer pool page. Functions like
page_rec_is_comp() cannot be used! */
if (rec_get_deleted_flag(rec, comp)) {
locks_ok_del_marked:
/* In delete-marked records, DB_TRX_ID must
always refer to an existing undo log record. */
ut_ad(index != clust_index
|| row_get_rec_trx_id(rec, index, offsets));
/* The record is delete-marked: we can skip it */
/* This is an optimization to skip setting the next key lock
on the record that follows this delete-marked record. This
optimization works because of the unique search criteria
which precludes the presence of a range lock between this
delete marked record and the record following it.
For now this is applicable only to clustered indexes while
doing a unique search except for HANDLER queries because
HANDLER allows NEXT and PREV even in unique search on
clustered index. There is scope for further optimization
applicable to unique secondary indexes. Current behaviour is
to widen the scope of a lock on an already delete marked record
if the same record is deleted twice by the same transaction */
if (index == clust_index && unique_search
&& !prebuilt->used_in_HANDLER) {
err = DB_RECORD_NOT_FOUND;
goto normal_return;
}
goto next_rec;
}
/* Check if the record matches the index condition. */
switch (row_search_idx_cond_check(buf, prebuilt, rec, offsets)) {
case ICP_NO_MATCH:
if (did_semi_consistent_read) {
row_unlock_for_mysql(prebuilt, TRUE);
}
goto next_rec;
case ICP_OUT_OF_RANGE:
case ICP_ABORTED_BY_USER:
case ICP_ERROR:
err = DB_RECORD_NOT_FOUND;
goto idx_cond_failed;
case ICP_MATCH:
break;
}
if (index != clust_index && prebuilt->need_to_access_clustered) {
if (row_search_with_covering_prefix(prebuilt, rec, offsets)) {
goto use_covering_index;
}
requires_clust_rec:
ut_ad(index != clust_index);
/* We use a 'goto' to the preceding label if a consistent
read of a secondary index record requires us to look up old
versions of the associated clustered index record. */
ut_ad(rec_offs_validate(rec, index, offsets));
/* It was a non-clustered index and we must fetch also the
clustered index record */
mtr_has_extra_clust_latch = TRUE;
ut_ad(!vrow);
/* The following call returns 'offsets' associated with
'clust_rec'. Note that 'clust_rec' can be an old version
built for a consistent read. */
err = row_sel_get_clust_rec_for_mysql(prebuilt, index, rec,
thr, &clust_rec,
&offsets, &heap,
need_vrow ? &vrow : NULL,
&mtr);
switch (err) {
case DB_SUCCESS:
if (clust_rec == NULL) {
/* The record did not exist in the read view */
ut_ad(prebuilt->select_lock_type == LOCK_NONE
|| dict_index_is_spatial(index));
goto next_rec;
}
break;
case DB_SUCCESS_LOCKED_REC:
ut_a(clust_rec != NULL);
if (srv_locks_unsafe_for_binlog
|| trx->isolation_level
<= TRX_ISO_READ_COMMITTED) {
/* Note that the clustered index record
was locked. */
prebuilt->new_rec_locks = 2;
}
err = DB_SUCCESS;
break;
default:
vrow = NULL;
goto lock_wait_or_error;
}
if (rec_get_deleted_flag(clust_rec, comp)) {
/* The record is delete marked: we can skip it */
if ((srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED)
&& prebuilt->select_lock_type != LOCK_NONE) {
/* No need to keep a lock on a delete-marked
record if we do not want to use next-key
locking. */
row_unlock_for_mysql(prebuilt, TRUE);
}
goto next_rec;
}
if (need_vrow && !vrow) {
if (!heap) {
heap = mem_heap_create(100);
}
row_sel_fill_vrow(rec, index, &vrow, heap);
}
result_rec = clust_rec;
ut_ad(rec_offs_validate(result_rec, clust_index, offsets));
if (prebuilt->idx_cond) {
/* Convert the record to MySQL format. We were
unable to do this in row_search_idx_cond_check(),
because the condition is on the secondary index
and the requested column is in the clustered index.
We convert all fields, including those that
may have been used in ICP, because the
secondary index may contain a column prefix
rather than the full column. Also, as noted
in Bug #56680, the column in the secondary
index may be in the wrong case, and the
authoritative case is in result_rec, the
appropriate version of the clustered index record. */
if (!row_sel_store_mysql_rec(
buf, prebuilt, result_rec, vrow,
true, clust_index, offsets)) {
goto next_rec;
}
}
} else {
use_covering_index:
result_rec = rec;
}
/* We found a qualifying record 'result_rec'. At this point,
'offsets' are associated with 'result_rec'. */
ut_ad(rec_offs_validate(result_rec,
result_rec != rec ? clust_index : index,
offsets));
ut_ad(!rec_get_deleted_flag(result_rec, comp));
/* Decide whether to prefetch extra rows.
At this point, the clustered index record is protected
by a page latch that was acquired when pcur was positioned.
The latch will not be released until mtr.commit(). */
if ((match_mode == ROW_SEL_EXACT
|| prebuilt->n_rows_fetched >= MYSQL_FETCH_CACHE_THRESHOLD)
&& prebuilt->select_lock_type == LOCK_NONE
&& !prebuilt->m_no_prefetch
&& !prebuilt->templ_contains_blob
&& !prebuilt->clust_index_was_generated
&& !prebuilt->used_in_HANDLER
&& prebuilt->template_type != ROW_MYSQL_DUMMY_TEMPLATE
&& !prebuilt->in_fts_query) {
/* Inside an update, for example, we do not cache rows,
since we may use the cursor position to do the actual
update, that is why we require ...lock_type == LOCK_NONE.
Since we keep space in prebuilt only for the BLOBs of
a single row, we cannot cache rows in the case there
are BLOBs in the fields to be fetched. In HANDLER we do
not cache rows because there the cursor is a scrollable
cursor. */
ut_a(prebuilt->n_fetch_cached < MYSQL_FETCH_CACHE_SIZE);
/* We only convert from InnoDB row format to MySQL row
format when ICP is disabled. */
if (!prebuilt->idx_cond) {
/* We use next_buf to track the allocation of buffers
where we store and enqueue the buffers for our
pre-fetch optimisation.
If next_buf == 0 then we store the converted record
directly into the MySQL record buffer (buf). If it is
!= 0 then we allocate a pre-fetch buffer and store the
converted record there.
If the conversion fails and the MySQL record buffer
was not written to then we reset next_buf so that
we can re-use the MySQL record buffer in the next
iteration. */
next_buf = next_buf
? row_sel_fetch_last_buf(prebuilt) : buf;
if (!row_sel_store_mysql_rec(
next_buf, prebuilt, result_rec, vrow,
result_rec != rec,
result_rec != rec ? clust_index : index,
offsets)) {
if (next_buf == buf) {
ut_a(prebuilt->n_fetch_cached == 0);
next_buf = 0;
}
/* Only fresh inserts may contain incomplete
externally stored columns. Pretend that such
records do not exist. Such records may only be
accessed at the READ UNCOMMITTED isolation
level or when rolling back a recovered
transaction. Rollback happens at a lower
level, not here. */
goto next_rec;
}
if (next_buf != buf) {
row_sel_enqueue_cache_row_for_mysql(
next_buf, prebuilt);
}
} else {
row_sel_enqueue_cache_row_for_mysql(buf, prebuilt);
}
if (prebuilt->n_fetch_cached < MYSQL_FETCH_CACHE_SIZE) {
goto next_rec;
}
} else {
if (UNIV_UNLIKELY
(prebuilt->template_type == ROW_MYSQL_DUMMY_TEMPLATE)) {
/* CHECK TABLE: fetch the row */
if (result_rec != rec
&& !prebuilt->need_to_access_clustered) {
/* We used 'offsets' for the clust
rec, recalculate them for 'rec' */
offsets = rec_get_offsets(rec, index, offsets,
true,
ULINT_UNDEFINED,
&heap);
result_rec = rec;
}
memcpy(buf + 4, result_rec
- rec_offs_extra_size(offsets),
rec_offs_size(offsets));
mach_write_to_4(buf,
rec_offs_extra_size(offsets) + 4);
} else if (!prebuilt->idx_cond) {
/* The record was not yet converted to MySQL format. */
if (!row_sel_store_mysql_rec(
buf, prebuilt, result_rec, vrow,
result_rec != rec,
result_rec != rec ? clust_index : index,
offsets)) {
/* Only fresh inserts may contain
incomplete externally stored
columns. Pretend that such records do
not exist. Such records may only be
accessed at the READ UNCOMMITTED
isolation level or when rolling back a
recovered transaction. Rollback
happens at a lower level, not here. */
goto next_rec;
}
}
if (prebuilt->clust_index_was_generated) {
row_sel_store_row_id_to_prebuilt(
prebuilt, result_rec,
result_rec == rec ? index : clust_index,
offsets);
}
}
/* From this point on, 'offsets' are invalid. */
/* We have an optimization to save CPU time: if this is a consistent
read on a unique condition on the clustered index, then we do not
store the pcur position, because any fetch next or prev will anyway
return 'end of file'. Exceptions are locking reads and the MySQL
HANDLER command where the user can move the cursor with PREV or NEXT
even after a unique search. */
err = DB_SUCCESS;
idx_cond_failed:
if (!unique_search
|| !dict_index_is_clust(index)
|| direction != 0
|| prebuilt->select_lock_type != LOCK_NONE
|| prebuilt->used_in_HANDLER) {
/* Inside an update always store the cursor position */
if (!spatial_search) {
btr_pcur_store_position(pcur, &mtr);
}
}
goto normal_return;
next_rec:
/* Reset the old and new "did semi-consistent read" flags. */
if (UNIV_UNLIKELY(prebuilt->row_read_type
== ROW_READ_DID_SEMI_CONSISTENT)) {
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
did_semi_consistent_read = FALSE;
prebuilt->new_rec_locks = 0;
vrow = NULL;
/*-------------------------------------------------------------*/
/* PHASE 5: Move the cursor to the next index record */
/* NOTE: For moves_up==FALSE, the mini-transaction will be
committed and restarted every time when switching b-tree
pages. For moves_up==TRUE in index condition pushdown, we can
scan an entire secondary index tree within a single
mini-transaction. As long as the prebuilt->idx_cond does not
match, we do not need to consult the clustered index or
return records to MySQL, and thus we can avoid repositioning
the cursor. What prevents us from buffer-fixing all leaf pages
within the mini-transaction is the btr_leaf_page_release()
call in btr_pcur_move_to_next_page(). Only the leaf page where
the cursor is positioned will remain buffer-fixed.
For R-tree spatial search, we also commit the mini-transaction
each time */
if (mtr_has_extra_clust_latch || spatial_search) {
/* If we have extra cluster latch, we must commit
mtr if we are moving to the next non-clustered
index record, because we could break the latching
order if we would access a different clustered
index page right away without releasing the previous. */
/* No need to do store restore for R-tree */
if (!spatial_search) {
btr_pcur_store_position(pcur, &mtr);
}
mtr.commit();
mtr_has_extra_clust_latch = FALSE;
mtr.start();
if (!spatial_search
&& sel_restore_position_for_mysql(&same_user_rec,
BTR_SEARCH_LEAF,
pcur, moves_up, &mtr)) {
goto rec_loop;
}
}
if (moves_up) {
if (UNIV_UNLIKELY(spatial_search)) {
if (rtr_pcur_move_to_next(
search_tuple, mode, pcur, 0, &mtr)) {
goto rec_loop;
}
} else {
const buf_block_t* block = btr_pcur_get_block(pcur);
/* This is based on btr_pcur_move_to_next(),
but avoids infinite read loop of a corrupted page. */
ut_ad(pcur->pos_state == BTR_PCUR_IS_POSITIONED);
ut_ad(pcur->latch_mode != BTR_NO_LATCHES);
pcur->old_stored = false;
if (btr_pcur_is_after_last_on_page(pcur)) {
if (btr_pcur_is_after_last_in_tree(pcur,
&mtr)) {
goto not_moved;
}
btr_pcur_move_to_next_page(pcur, &mtr);
if (UNIV_UNLIKELY(btr_pcur_get_block(pcur)
== block)) {
err = DB_CORRUPTION;
goto lock_wait_or_error;
}
} else {
btr_pcur_move_to_next_on_page(pcur);
}
goto rec_loop;
}
} else {
if (btr_pcur_move_to_prev(pcur, &mtr)) {
goto rec_loop;
}
}
not_moved:
if (!spatial_search) {
btr_pcur_store_position(pcur, &mtr);
}
err = match_mode ? DB_RECORD_NOT_FOUND : DB_END_OF_INDEX;
goto normal_return;
lock_wait_or_error:
/* Reset the old and new "did semi-consistent read" flags. */
if (UNIV_UNLIKELY(prebuilt->row_read_type
== ROW_READ_DID_SEMI_CONSISTENT)) {
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
did_semi_consistent_read = FALSE;
/*-------------------------------------------------------------*/
if (!dict_index_is_spatial(index)) {
if (rec) {
btr_pcur_store_position(pcur, &mtr);
}
}
lock_table_wait:
mtr.commit();
mtr_has_extra_clust_latch = FALSE;
trx->error_state = err;
/* The following is a patch for MySQL */
if (thr->is_active) {
que_thr_stop_for_mysql(thr);
}
thr->lock_state = QUE_THR_LOCK_ROW;
if (row_mysql_handle_errors(&err, trx, thr, NULL)) {
/* It was a lock wait, and it ended */
thr->lock_state = QUE_THR_LOCK_NOLOCK;
mtr.start();
/* Table lock waited, go try to obtain table lock
again */
if (table_lock_waited) {
table_lock_waited = FALSE;
goto wait_table_again;
}
if (!dict_index_is_spatial(index)) {
sel_restore_position_for_mysql(
&same_user_rec, BTR_SEARCH_LEAF, pcur,
moves_up, &mtr);
}
if ((srv_locks_unsafe_for_binlog
|| trx->isolation_level <= TRX_ISO_READ_COMMITTED)
&& !same_user_rec) {
/* Since we were not able to restore the cursor
on the same user record, we cannot use
row_unlock_for_mysql() to unlock any records, and
we must thus reset the new rec lock info. Since
in lock0lock.cc we have blocked the inheriting of gap
X-locks, we actually do not have any new record locks
set in this case.
Note that if we were able to restore on the 'same'
user record, it is still possible that we were actually
waiting on a delete-marked record, and meanwhile
it was removed by purge and inserted again by some
other user. But that is no problem, because in
rec_loop we will again try to set a lock, and
new_rec_lock_info in trx will be right at the end. */
prebuilt->new_rec_locks = 0;
}
mode = pcur->search_mode;
goto rec_loop;
}
thr->lock_state = QUE_THR_LOCK_NOLOCK;
goto func_exit;
normal_return:
/*-------------------------------------------------------------*/
que_thr_stop_for_mysql_no_error(thr, trx);
mtr.commit();
DEBUG_SYNC_C("row_search_for_mysql_before_return");
if (prebuilt->idx_cond != 0) {
/* When ICP is active we don't write to the MySQL buffer
directly, only to buffers that are enqueued in the pre-fetch
queue. We need to dequeue the first buffer and copy the contents
to the record buffer that was passed in by MySQL. */
if (prebuilt->n_fetch_cached > 0) {
row_sel_dequeue_cached_row_for_mysql(buf, prebuilt);
err = DB_SUCCESS;
}
} else if (next_buf != 0) {
/* We may or may not have enqueued some buffers to the
pre-fetch queue, but we definitely wrote to the record
buffer passed to use by MySQL. */
DEBUG_SYNC_C("row_search_cached_row");
err = DB_SUCCESS;
}
#ifdef UNIV_DEBUG
if (dict_index_is_spatial(index) && err != DB_SUCCESS
&& err != DB_END_OF_INDEX && err != DB_INTERRUPTED) {
rtr_node_path_t* path = pcur->btr_cur.rtr_info->path;
ut_ad(path->empty());
}
#endif
func_exit:
trx->op_info = "";
if (heap != NULL) {
mem_heap_free(heap);
}
/* Set or reset the "did semi-consistent read" flag on return.
The flag did_semi_consistent_read is set if and only if
the record being returned was fetched with a semi-consistent read. */
ut_ad(prebuilt->row_read_type != ROW_READ_WITH_LOCKS
|| !did_semi_consistent_read);
if (prebuilt->row_read_type != ROW_READ_WITH_LOCKS) {
if (did_semi_consistent_read) {
prebuilt->row_read_type = ROW_READ_DID_SEMI_CONSISTENT;
} else {
prebuilt->row_read_type = ROW_READ_TRY_SEMI_CONSISTENT;
}
}
ut_ad(!sync_check_iterate(sync_check()));
DEBUG_SYNC_C("innodb_row_search_for_mysql_exit");
DBUG_RETURN(err);
}
/********************************************************************//**
Count rows in a R-Tree leaf level.
@return DB_SUCCESS if successful */
dberr_t
row_count_rtree_recs(
/*=================*/
row_prebuilt_t* prebuilt, /*!< in: prebuilt struct for the
table handle; this contains the info
of search_tuple, index; if search
tuple contains 0 fields then we
position the cursor at the start or
the end of the index, depending on
'mode' */
ulint* n_rows) /*!< out: number of entries
seen in the consistent read */
{
dict_index_t* index = prebuilt->index;
dberr_t ret = DB_SUCCESS;
mtr_t mtr;
mem_heap_t* heap;
dtuple_t* entry;
dtuple_t* search_entry = prebuilt->search_tuple;
ulint entry_len;
ulint i;
byte* buf;
ut_a(dict_index_is_spatial(index));
*n_rows = 0;
heap = mem_heap_create(256);
/* Build a search tuple. */
entry_len = dict_index_get_n_fields(index);
entry = dtuple_create(heap, entry_len);
for (i = 0; i < entry_len; i++) {
const dict_field_t* ind_field
= dict_index_get_nth_field(index, i);
const dict_col_t* col
= ind_field->col;
dfield_t* dfield
= dtuple_get_nth_field(entry, i);
if (i == 0) {
double* mbr;
double tmp_mbr[SPDIMS * 2];
dfield->type.mtype = DATA_GEOMETRY;
dfield->type.prtype |= DATA_GIS_MBR;
/* Allocate memory for mbr field */
mbr = static_cast<double*>
(mem_heap_alloc(heap, DATA_MBR_LEN));
/* Set mbr field data. */
dfield_set_data(dfield, mbr, DATA_MBR_LEN);
for (uint j = 0; j < SPDIMS; j++) {
tmp_mbr[j * 2] = DBL_MAX;
tmp_mbr[j * 2 + 1] = -DBL_MAX;
}
dfield_write_mbr(dfield, tmp_mbr);
continue;
}
dfield->type.mtype = col->mtype;
dfield->type.prtype = col->prtype;
}
prebuilt->search_tuple = entry;
ulint bufsize = ut_max(UNIV_PAGE_SIZE, prebuilt->mysql_row_len);
buf = static_cast<byte*>(ut_malloc_nokey(bufsize));
ulint cnt = 1000;
ret = row_search_for_mysql(buf, PAGE_CUR_WITHIN, prebuilt, 0, 0);
loop:
/* Check thd->killed every 1,000 scanned rows */
if (--cnt == 0) {
if (trx_is_interrupted(prebuilt->trx)) {
ret = DB_INTERRUPTED;
goto func_exit;
}
cnt = 1000;
}
switch (ret) {
case DB_SUCCESS:
break;
case DB_DEADLOCK:
case DB_LOCK_TABLE_FULL:
case DB_LOCK_WAIT_TIMEOUT:
case DB_INTERRUPTED:
goto func_exit;
default:
/* fall through (this error is ignored by CHECK TABLE) */
case DB_END_OF_INDEX:
ret = DB_SUCCESS;
func_exit:
prebuilt->search_tuple = search_entry;
ut_free(buf);
mem_heap_free(heap);
return(ret);
}
*n_rows = *n_rows + 1;
ret = row_search_for_mysql(
buf, PAGE_CUR_WITHIN, prebuilt, 0, ROW_SEL_NEXT);
goto loop;
}
/*******************************************************************//**
Read the AUTOINC column from the current row. If the value is less than
0 and the type is not unsigned then we reset the value to 0.
@return value read from the column */
static
ib_uint64_t
row_search_autoinc_read_column(
/*===========================*/
dict_index_t* index, /*!< in: index to read from */
const rec_t* rec, /*!< in: current rec */
ulint col_no, /*!< in: column number */
ulint mtype, /*!< in: column main type */
ibool unsigned_type) /*!< in: signed or unsigned flag */
{
ulint len;
const byte* data;
ib_uint64_t value;
mem_heap_t* heap = NULL;
ulint offsets_[REC_OFFS_NORMAL_SIZE];
ulint* offsets = offsets_;
rec_offs_init(offsets_);
ut_ad(page_rec_is_leaf(rec));
offsets = rec_get_offsets(rec, index, offsets, true,
col_no + 1, &heap);
if (rec_offs_nth_sql_null(offsets, col_no)) {
/* There is no non-NULL value in the auto-increment column. */
value = 0;
goto func_exit;
}
data = rec_get_nth_field(rec, offsets, col_no, &len);
value = row_parse_int(data, len, mtype, unsigned_type);
func_exit:
if (UNIV_LIKELY_NULL(heap)) {
mem_heap_free(heap);
}
return(value);
}
/** Get the maximum and non-delete-marked record in an index.
@param[in] index index tree
@param[in,out] mtr mini-transaction (may be committed and restarted)
@return maximum record, page s-latched in mtr
@retval NULL if there are no records, or if all of them are delete-marked */
static
const rec_t*
row_search_get_max_rec(
dict_index_t* index,
mtr_t* mtr)
{
btr_pcur_t pcur;
const rec_t* rec;
/* Open at the high/right end (false), and init cursor */
btr_pcur_open_at_index_side(
false, index, BTR_SEARCH_LEAF, &pcur, true, 0, mtr);
do {
const page_t* page;
page = btr_pcur_get_page(&pcur);
rec = page_find_rec_max_not_deleted(page);
if (page_rec_is_user_rec(rec)) {
break;
} else {
rec = NULL;
}
btr_pcur_move_before_first_on_page(&pcur);
} while (btr_pcur_move_to_prev(&pcur, mtr));
btr_pcur_close(&pcur);
return(rec);
}
/** Read the max AUTOINC value from an index.
@param[in] index index starting with an AUTO_INCREMENT column
@return the largest AUTO_INCREMENT value
@retval 0 if no records were found */
ib_uint64_t
row_search_max_autoinc(dict_index_t* index)
{
const dict_field_t* dfield = dict_index_get_nth_field(index, 0);
ib_uint64_t value = 0;
mtr_t mtr;
mtr.start();
if (const rec_t* rec = row_search_get_max_rec(index, &mtr)) {
value = row_search_autoinc_read_column(
index, rec, 0,
dfield->col->mtype,
dfield->col->prtype & DATA_UNSIGNED);
}
mtr.commit();
return(value);
}
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