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mariadb/storage/innobase/trx/trx0rec.cc
Sergei Golubchik 9ee09a33bb Merge branch '11.7' into 11.8
2025-02-11 20:29:43 +01:00

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/*****************************************************************************
Copyright (c) 1996, 2019, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2017, 2022, MariaDB Corporation.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file trx/trx0rec.cc
Transaction undo log record
Created 3/26/1996 Heikki Tuuri
*******************************************************/
#include "trx0rec.h"
#include "fsp0fsp.h"
#include "mach0data.h"
#include "trx0undo.h"
#include "mtr0log.h"
#include "dict0dict.h"
#include "ut0mem.h"
#include "row0ext.h"
#include "row0upd.h"
#include "que0que.h"
#include "trx0purge.h"
#include "trx0rseg.h"
#include "row0row.h"
#include "row0mysql.h"
#include "row0ins.h"
#include "mariadb_stats.h"
/** The search tuple corresponding to TRX_UNDO_INSERT_METADATA. */
const dtuple_t trx_undo_metadata = {
/* This also works for REC_INFO_METADATA_ALTER, because the
delete-mark (REC_INFO_DELETED_FLAG) is ignored when searching. */
REC_INFO_METADATA_ADD, 0, 0, 0, nullptr, nullptr
#ifdef UNIV_DEBUG
, DATA_TUPLE_MAGIC_N
#endif /* UNIV_DEBUG */
};
/*=========== UNDO LOG RECORD CREATION AND DECODING ====================*/
/** Calculate the free space left for extending an undo log record.
@param undo_block undo log page
@param ptr current end of the undo page
@return bytes left */
static ulint trx_undo_left(const buf_block_t *undo_block, const byte *ptr)
{
ut_ad(ptr >=
&undo_block->page.frame[TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE]);
/* The 10 is supposed to be an extra safety margin (and needed for
compatibility with older versions) */
lint left= srv_page_size - (ptr - undo_block->page.frame) -
(10 + FIL_PAGE_DATA_END);
ut_ad(left >= 0);
return left < 0 ? 0 : static_cast<ulint>(left);
}
/**********************************************************************//**
Set the next and previous pointers in the undo page for the undo record
that was written to ptr. Update the first free value by the number of bytes
written for this undo record.
@return offset of the inserted entry on the page if succeeded, 0 if fail */
static
uint16_t
trx_undo_page_set_next_prev_and_add(
/*================================*/
buf_block_t* undo_block, /*!< in/out: undo log page */
byte* ptr, /*!< in: ptr up to where data has been
written on this undo page. */
mtr_t* mtr) /*!< in: mtr */
{
ut_ad(page_align(ptr) == undo_block->page.frame);
if (UNIV_UNLIKELY(trx_undo_left(undo_block, ptr) < 2))
return 0;
byte *ptr_to_first_free= my_assume_aligned<2>(TRX_UNDO_PAGE_HDR +
TRX_UNDO_PAGE_FREE +
undo_block->page.frame);
const uint16_t first_free= mach_read_from_2(ptr_to_first_free);
/* Write offset of the previous undo log record */
memcpy(ptr, ptr_to_first_free, 2);
ptr += 2;
const uint16_t end_of_rec= static_cast<uint16_t>
(ptr - undo_block->page.frame);
/* Update the offset to first free undo record */
mach_write_to_2(ptr_to_first_free, end_of_rec);
/* Write offset of the next undo log record */
memcpy(undo_block->page.frame + first_free, ptr_to_first_free, 2);
const byte *start= undo_block->page.frame + first_free + 2;
mtr->undo_append(*undo_block, start, ptr - start - 2);
return first_free;
}
/** Virtual column undo log version. To distinguish it from a length value
in 5.7.8 undo log, it starts with 0xF1 */
static const ulint VIRTUAL_COL_UNDO_FORMAT_1 = 0xF1;
/** Write virtual column index info (index id and column position in index)
to the undo log
@param[in,out] undo_block undo log page
@param[in] table the table
@param[in] pos the virtual column position
@param[in] ptr undo log record being written
@param[in] first_v_col whether this is the first virtual column
which could start with a version marker
@return new undo log pointer */
static
byte*
trx_undo_log_v_idx(
buf_block_t* undo_block,
const dict_table_t* table,
ulint pos,
byte* ptr,
bool first_v_col)
{
ut_ad(pos < table->n_v_def);
dict_v_col_t* vcol = dict_table_get_nth_v_col(table, pos);
byte* old_ptr;
ut_ad(!vcol->v_indexes.empty());
ulint size = first_v_col ? 1 + 2 : 2;
const ulint avail = trx_undo_left(undo_block, ptr);
/* The mach_write_compressed(ptr, flen) in
trx_undo_page_report_modify() will consume additional 1 to 5 bytes. */
if (avail < size + 5) {
return(NULL);
}
ulint n_idx = 0;
for (const auto& v_index : vcol->v_indexes) {
n_idx++;
/* FIXME: index->id is 64 bits! */
size += mach_get_compressed_size(uint32_t(v_index.index->id));
size += mach_get_compressed_size(v_index.nth_field);
}
size += mach_get_compressed_size(n_idx);
if (avail < size + 5) {
return(NULL);
}
ut_d(const byte* orig_ptr = ptr);
if (first_v_col) {
/* write the version marker */
mach_write_to_1(ptr, VIRTUAL_COL_UNDO_FORMAT_1);
ptr += 1;
}
old_ptr = ptr;
ptr += 2;
ptr += mach_write_compressed(ptr, n_idx);
for (const auto& v_index : vcol->v_indexes) {
ptr += mach_write_compressed(
/* FIXME: index->id is 64 bits! */
ptr, uint32_t(v_index.index->id));
ptr += mach_write_compressed(ptr, v_index.nth_field);
}
ut_ad(orig_ptr + size == ptr);
mach_write_to_2(old_ptr, ulint(ptr - old_ptr));
return(ptr);
}
/** Read virtual column index from undo log, and verify the column is still
indexed, and return its position
@param[in] table the table
@param[in] ptr undo log pointer
@param[out] col_pos the column number or FIL_NULL
if the column is not indexed any more
@return remaining part of undo log record after reading these values */
static
const byte*
trx_undo_read_v_idx_low(
const dict_table_t* table,
const byte* ptr,
uint32_t* col_pos)
{
ulint len = mach_read_from_2(ptr);
const byte* old_ptr = ptr;
*col_pos = FIL_NULL;
ptr += 2;
ulint num_idx = mach_read_next_compressed(&ptr);
ut_ad(num_idx > 0);
dict_index_t* clust_index = dict_table_get_first_index(table);
for (ulint i = 0; i < num_idx; i++) {
index_id_t id = mach_read_next_compressed(&ptr);
ulint pos = mach_read_next_compressed(&ptr);
dict_index_t* index = dict_table_get_next_index(clust_index);
while (index != NULL) {
/* Return if we find a matching index.
TODO: in the future, it might be worth to add
checks on other indexes */
if (index->id == id) {
const dict_col_t* col = dict_index_get_nth_col(
index, pos);
ut_ad(col->is_virtual());
const dict_v_col_t* vcol = reinterpret_cast<
const dict_v_col_t*>(col);
*col_pos = vcol->v_pos;
return(old_ptr + len);
}
index = dict_table_get_next_index(index);
}
}
return(old_ptr + len);
}
/** Read virtual column index from undo log or online log if the log
contains such info, and in the undo log case, verify the column is
still indexed, and output its position
@param[in] table the table
@param[in] ptr undo log pointer
@param[in] first_v_col if this is the first virtual column, which
has the version marker
@param[in,out] is_undo_log this function is used to parse both undo log,
and online log for virtual columns. So
check to see if this is undo log. When
first_v_col is true, is_undo_log is output,
when first_v_col is false, is_undo_log is input
@param[out] field_no the column number, or FIL_NULL if not indexed
@return remaining part of undo log record after reading these values */
const byte*
trx_undo_read_v_idx(
const dict_table_t* table,
const byte* ptr,
bool first_v_col,
bool* is_undo_log,
uint32_t* field_no)
{
/* Version marker only put on the first virtual column */
if (first_v_col) {
/* Undo log has the virtual undo log marker */
*is_undo_log = (mach_read_from_1(ptr)
== VIRTUAL_COL_UNDO_FORMAT_1);
if (*is_undo_log) {
ptr += 1;
}
}
if (*is_undo_log) {
ptr = trx_undo_read_v_idx_low(table, ptr, field_no);
} else {
*field_no -= REC_MAX_N_FIELDS;
}
return(ptr);
}
/** Reports in the undo log of an insert of virtual columns.
@param[in] undo_block undo log page
@param[in] table the table
@param[in] row dtuple contains the virtual columns
@param[in,out] ptr log ptr
@return true if write goes well, false if out of space */
static
bool
trx_undo_report_insert_virtual(
buf_block_t* undo_block,
dict_table_t* table,
const dtuple_t* row,
byte** ptr)
{
byte* start = *ptr;
bool first_v_col = true;
if (trx_undo_left(undo_block, *ptr) < 2) {
return(false);
}
/* Reserve 2 bytes to write the number
of bytes the stored fields take in this
undo record */
*ptr += 2;
for (ulint col_no = 0; col_no < dict_table_get_n_v_cols(table);
col_no++) {
const dict_v_col_t* col
= dict_table_get_nth_v_col(table, col_no);
if (col->m_col.ord_part) {
/* make sure enought space to write the length */
if (trx_undo_left(undo_block, *ptr) < 5) {
return(false);
}
ulint pos = col_no;
pos += REC_MAX_N_FIELDS;
*ptr += mach_write_compressed(*ptr, pos);
*ptr = trx_undo_log_v_idx(undo_block, table,
col_no, *ptr, first_v_col);
first_v_col = false;
if (*ptr == NULL) {
return(false);
}
const dfield_t* vfield = dtuple_get_nth_v_field(
row, col->v_pos);
switch (ulint flen = vfield->len) {
case 0: case UNIV_SQL_NULL:
if (trx_undo_left(undo_block, *ptr) < 5) {
return(false);
}
*ptr += mach_write_compressed(*ptr, flen);
break;
default:
ulint max_len
= dict_max_v_field_len_store_undo(
table, col_no);
if (flen > max_len) {
flen = max_len;
}
if (trx_undo_left(undo_block, *ptr)
< flen + 5) {
return(false);
}
*ptr += mach_write_compressed(*ptr, flen);
memcpy(*ptr, vfield->data, flen);
*ptr += flen;
}
}
}
/* Always mark the end of the log with 2 bytes length field */
mach_write_to_2(start, ulint(*ptr - start));
return(true);
}
/** Reports in the undo log of an insert of a clustered index record.
@param undo_block undo log page
@param trx transaction
@param index clustered index
@param clust_entry index entry which will be inserted to the
clustered index
@param mtr mini-transaction
@param write_empty write empty table undo log record
@return offset of the inserted entry on the page if succeed, 0 if fail */
static
uint16_t
trx_undo_page_report_insert(
buf_block_t* undo_block,
trx_t* trx,
dict_index_t* index,
const dtuple_t* clust_entry,
mtr_t* mtr,
bool write_empty)
{
ut_ad(index->is_primary());
/* MariaDB 10.3.1+ in trx_undo_page_init() always initializes
TRX_UNDO_PAGE_TYPE as 0, but previous versions wrote
TRX_UNDO_INSERT == 1 into insert_undo pages,
or TRX_UNDO_UPDATE == 2 into update_undo pages. */
ut_ad(mach_read_from_2(TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_TYPE
+ undo_block->page.frame) <= 2);
uint16_t first_free = mach_read_from_2(my_assume_aligned<2>
(TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_FREE
+ undo_block->page.frame));
byte* ptr = undo_block->page.frame + first_free;
if (trx_undo_left(undo_block, ptr) < 2 + 1 + 11 + 11) {
/* Not enough space for writing the general parameters */
return(0);
}
/* Reserve 2 bytes for the pointer to the next undo log record */
ptr += 2;
/* Store first some general parameters to the undo log */
*ptr++ = TRX_UNDO_INSERT_REC;
ptr += mach_u64_write_much_compressed(ptr, trx->undo_no);
ptr += mach_u64_write_much_compressed(ptr, index->table->id);
if (write_empty) {
/* Table is in bulk operation */
undo_block->page.frame[first_free + 2] = TRX_UNDO_EMPTY;
goto done;
}
/*----------------------------------------*/
/* Store then the fields required to uniquely determine the record
to be inserted in the clustered index */
if (UNIV_UNLIKELY(clust_entry->info_bits != 0)) {
ut_ad(clust_entry->is_metadata());
ut_ad(index->is_instant());
ut_ad(undo_block->page.frame[first_free + 2]
== TRX_UNDO_INSERT_REC);
undo_block->page.frame[first_free + 2]
= TRX_UNDO_INSERT_METADATA;
goto done;
}
for (unsigned i = 0; i < dict_index_get_n_unique(index); i++) {
const dfield_t* field = dtuple_get_nth_field(clust_entry, i);
ulint flen = dfield_get_len(field);
if (trx_undo_left(undo_block, ptr) < 5) {
return(0);
}
ptr += mach_write_compressed(ptr, flen);
switch (flen) {
case 0: case UNIV_SQL_NULL:
break;
default:
if (trx_undo_left(undo_block, ptr) < flen) {
return(0);
}
memcpy(ptr, dfield_get_data(field), flen);
ptr += flen;
}
}
if (index->table->n_v_cols) {
if (!trx_undo_report_insert_virtual(
undo_block, index->table, clust_entry, &ptr)) {
return(0);
}
}
done:
return(trx_undo_page_set_next_prev_and_add(undo_block, ptr, mtr));
}
/**********************************************************************//**
Reads from an undo log record the general parameters.
@return remaining part of undo log record after reading these values */
const byte*
trx_undo_rec_get_pars(
/*==================*/
const trx_undo_rec_t* undo_rec, /*!< in: undo log record */
byte* type, /*!< out: undo record type:
TRX_UNDO_INSERT_REC, ... */
byte* cmpl_info, /*!< out: compiler info, relevant only
for update type records */
bool* updated_extern, /*!< out: true if we updated an
externally stored fild */
undo_no_t* undo_no, /*!< out: undo log record number */
table_id_t* table_id) /*!< out: table id */
{
ulint type_cmpl;
type_cmpl = undo_rec[2];
const byte *ptr = undo_rec + 3;
*updated_extern = !!(type_cmpl & TRX_UNDO_UPD_EXTERN);
type_cmpl &= ~TRX_UNDO_UPD_EXTERN;
*type = type_cmpl & (TRX_UNDO_CMPL_INFO_MULT - 1);
ut_ad(*type >= TRX_UNDO_RENAME_TABLE);
ut_ad(*type <= TRX_UNDO_EMPTY);
*cmpl_info = byte(type_cmpl / TRX_UNDO_CMPL_INFO_MULT);
*undo_no = mach_read_next_much_compressed(&ptr);
*table_id = mach_read_next_much_compressed(&ptr);
ut_ad(*table_id);
return ptr;
}
/** Read from an undo log record a non-virtual column value.
@param ptr pointer to remaining part of the undo record
@param field stored field
@param len length of the field, or UNIV_SQL_NULL
@param orig_len original length of the locally stored part
of an externally stored column, or 0
@return remaining part of undo log record after reading these values */
const byte *trx_undo_rec_get_col_val(const byte *ptr, const byte **field,
uint32_t *len, uint32_t *orig_len)
{
*len = mach_read_next_compressed(&ptr);
*orig_len = 0;
switch (*len) {
case UNIV_SQL_NULL:
*field = NULL;
break;
case UNIV_EXTERN_STORAGE_FIELD:
*orig_len = mach_read_next_compressed(&ptr);
*len = mach_read_next_compressed(&ptr);
*field = ptr;
ptr += *len & ~SPATIAL_STATUS_MASK;
ut_ad(*orig_len >= BTR_EXTERN_FIELD_REF_SIZE);
ut_ad(*len > *orig_len);
/* @see dtuple_convert_big_rec() */
ut_ad(*len >= BTR_EXTERN_FIELD_REF_SIZE);
/* we do not have access to index->table here
ut_ad(dict_table_has_atomic_blobs(index->table)
|| *len >= col->max_prefix
+ BTR_EXTERN_FIELD_REF_SIZE);
*/
*len += UNIV_EXTERN_STORAGE_FIELD;
break;
default:
*field = ptr;
if (*len >= UNIV_EXTERN_STORAGE_FIELD) {
ptr += (*len - UNIV_EXTERN_STORAGE_FIELD)
& ~SPATIAL_STATUS_MASK;
} else {
ptr += *len;
}
}
return ptr;
}
/*******************************************************************//**
Builds a row reference from an undo log record.
@return pointer to remaining part of undo record */
const byte*
trx_undo_rec_get_row_ref(
/*=====================*/
const byte* ptr, /*!< in: remaining part of a copy of an undo log
record, at the start of the row reference;
NOTE that this copy of the undo log record must
be preserved as long as the row reference is
used, as we do NOT copy the data in the
record! */
dict_index_t* index, /*!< in: clustered index */
const dtuple_t**ref, /*!< out, own: row reference */
mem_heap_t* heap) /*!< in: memory heap from which the memory
needed is allocated */
{
ut_ad(index->is_primary());
const uint16_t ref_len = dict_index_get_n_unique(index);
dtuple_t* tuple = dtuple_create(heap, ref_len);
*ref = tuple;
dict_index_copy_types(tuple, index, ref_len);
for (ulint i = 0; i < ref_len; i++) {
const byte* field;
uint32_t len, orig_len;
dfield_t* dfield = dtuple_get_nth_field(tuple, i);
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
dfield_set_data(dfield, field, len);
}
return ptr;
}
/** Skip a row reference from an undo log record.
@param ptr part of an update undo log record
@param index clustered index
@return pointer to remaining part of undo record */
static const byte *trx_undo_rec_skip_row_ref(const byte *ptr,
const dict_index_t *index)
{
ut_ad(index->is_primary());
ulint ref_len = dict_index_get_n_unique(index);
for (ulint i = 0; i < ref_len; i++) {
const byte* field;
uint32_t len, orig_len;
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
}
return(ptr);
}
/** Fetch a prefix of an externally stored column, for writing to the undo
log of an update or delete marking of a clustered index record.
@param[out] ext_buf buffer to hold the prefix data and BLOB pointer
@param[in] prefix_len prefix size to store in the undo log
@param[in] zip_size ROW_FORMAT=COMPRESSED page size, or 0
@param[in] field an externally stored column
@param[in,out] len input: length of field; output: used length of
ext_buf
@return ext_buf */
static
byte*
trx_undo_page_fetch_ext(
byte* ext_buf,
ulint prefix_len,
ulint zip_size,
const byte* field,
ulint* len)
{
/* Fetch the BLOB. */
ulint ext_len = btr_copy_externally_stored_field_prefix(
ext_buf, prefix_len, zip_size, field, *len);
/* BLOBs should always be nonempty. */
ut_a(ext_len);
/* Append the BLOB pointer to the prefix. */
memcpy(ext_buf + ext_len,
field + *len - BTR_EXTERN_FIELD_REF_SIZE,
BTR_EXTERN_FIELD_REF_SIZE);
*len = ext_len + BTR_EXTERN_FIELD_REF_SIZE;
return(ext_buf);
}
/** Writes to the undo log a prefix of an externally stored column.
@param[out] ptr undo log position, at least 15 bytes must be
available
@param[out] ext_buf a buffer of DICT_MAX_FIELD_LEN_BY_FORMAT()
size, or NULL when should not fetch a longer
prefix
@param[in] prefix_len prefix size to store in the undo log
@param[in] zip_size ROW_FORMAT=COMPRESSED page size, or 0
@param[in,out] field the locally stored part of the externally
stored column
@param[in,out] len length of field, in bytes
@param[in] spatial_status whether the column is used by spatial index or
regular index
@return undo log position */
static
byte*
trx_undo_page_report_modify_ext(
byte* ptr,
byte* ext_buf,
ulint prefix_len,
ulint zip_size,
const byte** field,
ulint* len,
spatial_status_t spatial_status)
{
ulint spatial_len= 0;
switch (spatial_status) {
case SPATIAL_UNKNOWN:
case SPATIAL_NONE:
break;
case SPATIAL_MIXED:
case SPATIAL_ONLY:
spatial_len = DATA_MBR_LEN;
break;
}
/* Encode spatial status into length. */
spatial_len |= ulint(spatial_status) << SPATIAL_STATUS_SHIFT;
if (spatial_status == SPATIAL_ONLY) {
/* If the column is only used by gis index, log its
MBR is enough.*/
ptr += mach_write_compressed(ptr, UNIV_EXTERN_STORAGE_FIELD
+ spatial_len);
return(ptr);
}
if (ext_buf) {
ut_a(prefix_len > 0);
/* If an ordering column is externally stored, we will
have to store a longer prefix of the field. In this
case, write to the log a marker followed by the
original length and the real length of the field. */
ptr += mach_write_compressed(ptr, UNIV_EXTERN_STORAGE_FIELD);
ptr += mach_write_compressed(ptr, *len);
*field = trx_undo_page_fetch_ext(ext_buf, prefix_len,
zip_size, *field, len);
ptr += mach_write_compressed(ptr, *len + spatial_len);
} else {
ptr += mach_write_compressed(ptr, UNIV_EXTERN_STORAGE_FIELD
+ *len + spatial_len);
}
return(ptr);
}
/** Get MBR from a Geometry column stored externally
@param[out] mbr MBR to fill
@param[in] zip_size ROW_FORMAT=COMPRESSED page size, or 0
@param[in] field field contain the geometry data
@param[in,out] len length of field, in bytes
*/
static
void
trx_undo_get_mbr_from_ext(
/*======================*/
double* mbr,
ulint zip_size,
const byte* field,
ulint* len)
{
uchar* dptr = NULL;
ulint dlen;
mem_heap_t* heap = mem_heap_create(100);
dptr = btr_copy_externally_stored_field(
&dlen, field, zip_size, *len, heap);
if (dlen <= GEO_DATA_HEADER_SIZE) {
for (uint i = 0; i < SPDIMS; ++i) {
mbr[i * 2] = DBL_MAX;
mbr[i * 2 + 1] = -DBL_MAX;
}
} else {
rtree_mbr_from_wkb(dptr + GEO_DATA_HEADER_SIZE,
static_cast<uint>(dlen
- GEO_DATA_HEADER_SIZE), SPDIMS, mbr);
}
mem_heap_free(heap);
}
/**********************************************************************//**
Reports in the undo log of an update or delete marking of a clustered index
record.
@return byte offset of the inserted undo log entry on the page if
succeed, 0 if fail */
static
uint16_t
trx_undo_page_report_modify(
/*========================*/
buf_block_t* undo_block, /*!< in: undo log page */
trx_t* trx, /*!< in: transaction */
dict_index_t* index, /*!< in: clustered index where update or
delete marking is done */
const rec_t* rec, /*!< in: clustered index record which
has NOT yet been modified */
const rec_offs* offsets, /*!< in: rec_get_offsets(rec, index) */
const upd_t* update, /*!< in: update vector which tells the
columns to be updated; in the case of
a delete, this should be set to NULL */
ulint cmpl_info, /*!< in: compiler info on secondary
index updates */
const dtuple_t* row, /*!< in: clustered index row contains
virtual column info */
mtr_t* mtr) /*!< in: mtr */
{
ut_ad(index->is_primary());
ut_ad(rec_offs_validate(rec, index, offsets));
/* MariaDB 10.3.1+ in trx_undo_page_init() always initializes
TRX_UNDO_PAGE_TYPE as 0, but previous versions wrote
TRX_UNDO_INSERT == 1 into insert_undo pages,
or TRX_UNDO_UPDATE == 2 into update_undo pages. */
ut_ad(mach_read_from_2(TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_TYPE
+ undo_block->page.frame) <= 2);
byte* ptr_to_first_free = my_assume_aligned<2>(
TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE
+ undo_block->page.frame);
const uint16_t first_free = mach_read_from_2(ptr_to_first_free);
byte *ptr = undo_block->page.frame + first_free;
if (trx_undo_left(undo_block, ptr) < 50) {
/* NOTE: the value 50 must be big enough so that the general
fields written below fit on the undo log page */
return 0;
}
/* Reserve 2 bytes for the pointer to the next undo log record */
ptr += 2;
dict_table_t* table = index->table;
const byte* field;
ulint flen;
ulint col_no;
ulint type_cmpl;
byte* type_cmpl_ptr;
ulint i;
trx_id_t trx_id;
ibool ignore_prefix = FALSE;
byte ext_buf[REC_VERSION_56_MAX_INDEX_COL_LEN
+ BTR_EXTERN_FIELD_REF_SIZE];
bool first_v_col = true;
/* Store first some general parameters to the undo log */
if (!update) {
ut_ad(!rec_is_delete_marked(rec, dict_table_is_comp(table)));
type_cmpl = TRX_UNDO_DEL_MARK_REC;
} else if (rec_is_delete_marked(rec, dict_table_is_comp(table))) {
/* In delete-marked records, DB_TRX_ID must
always refer to an existing update_undo log record. */
ut_ad(row_get_rec_trx_id(rec, index, offsets));
type_cmpl = TRX_UNDO_UPD_DEL_REC;
/* We are about to update a delete marked record.
We don't typically need the prefix in this case unless
the delete marking is done by the same transaction
(which we check below). */
ignore_prefix = TRUE;
} else {
type_cmpl = TRX_UNDO_UPD_EXIST_REC;
}
type_cmpl |= cmpl_info * TRX_UNDO_CMPL_INFO_MULT;
type_cmpl_ptr = ptr;
*ptr++ = (byte) type_cmpl;
ptr += mach_u64_write_much_compressed(ptr, trx->undo_no);
ptr += mach_u64_write_much_compressed(ptr, table->id);
/*----------------------------------------*/
/* Store the state of the info bits */
*ptr++ = (byte) rec_get_info_bits(rec, dict_table_is_comp(table));
/* Store the values of the system columns */
field = rec_get_nth_field(rec, offsets, index->db_trx_id(), &flen);
ut_ad(flen == DATA_TRX_ID_LEN);
trx_id = trx_read_trx_id(field);
/* If it is an update of a delete marked record, then we are
allowed to ignore blob prefixes if the delete marking was done
by some other trx as it must have committed by now for us to
allow an over-write. */
if (trx_id == trx->id) {
ignore_prefix = false;
}
ptr += mach_u64_write_compressed(ptr, trx_id);
field = rec_get_nth_field(rec, offsets, index->db_roll_ptr(), &flen);
ut_ad(flen == DATA_ROLL_PTR_LEN);
ut_ad(memcmp(field, field_ref_zero, DATA_ROLL_PTR_LEN));
ptr += mach_u64_write_compressed(ptr, trx_read_roll_ptr(field));
/*----------------------------------------*/
/* Store then the fields required to uniquely determine the
record which will be modified in the clustered index */
for (i = 0; i < dict_index_get_n_unique(index); i++) {
/* The ordering columns must not be instant added columns. */
ut_ad(!rec_offs_nth_default(offsets, i));
field = rec_get_nth_field(rec, offsets, i, &flen);
/* The ordering columns must not be stored externally. */
ut_ad(!rec_offs_nth_extern(offsets, i));
ut_ad(dict_index_get_nth_col(index, i)->ord_part);
if (trx_undo_left(undo_block, ptr) < 5) {
return(0);
}
ptr += mach_write_compressed(ptr, flen);
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_block, ptr) < flen) {
return(0);
}
memcpy(ptr, field, flen);
ptr += flen;
}
}
/*----------------------------------------*/
/* Save to the undo log the old values of the columns to be updated. */
if (update) {
if (trx_undo_left(undo_block, ptr) < 5) {
return(0);
}
ulint n_updated = upd_get_n_fields(update);
/* If this is an online update while an inplace alter table
is in progress and the table has virtual column, we will
need to double check if there are any non-indexed columns
being registered in update vector in case they will be indexed
in new table */
if (dict_index_is_online_ddl(index) && table->n_v_cols > 0) {
for (i = 0; i < upd_get_n_fields(update); i++) {
upd_field_t* fld = upd_get_nth_field(
update, i);
ulint pos = fld->field_no;
/* These columns must not have an index
on them */
if (upd_fld_is_virtual_col(fld)
&& dict_table_get_nth_v_col(
table, pos)->v_indexes.empty()) {
n_updated--;
}
}
}
i = 0;
if (UNIV_UNLIKELY(update->is_alter_metadata())) {
ut_ad(update->n_fields >= 1);
ut_ad(!upd_fld_is_virtual_col(&update->fields[0]));
ut_ad(update->fields[0].field_no
== index->first_user_field());
ut_ad(!dfield_is_ext(&update->fields[0].new_val));
ut_ad(!dfield_is_null(&update->fields[0].new_val));
/* The instant ADD COLUMN metadata record does not
contain the BLOB. Do not write anything for it. */
i = !rec_is_alter_metadata(rec, *index);
n_updated -= i;
}
ptr += mach_write_compressed(ptr, n_updated);
for (; i < upd_get_n_fields(update); i++) {
if (trx_undo_left(undo_block, ptr) < 5) {
return 0;
}
upd_field_t* fld = upd_get_nth_field(update, i);
bool is_virtual = upd_fld_is_virtual_col(fld);
ulint max_v_log_len = 0;
ulint pos = fld->field_no;
const dict_col_t* col = NULL;
if (is_virtual) {
/* Skip the non-indexed column, during
an online alter table */
if (dict_index_is_online_ddl(index)
&& dict_table_get_nth_v_col(
table, pos)->v_indexes.empty()) {
continue;
}
/* add REC_MAX_N_FIELDS to mark this
is a virtual col */
ptr += mach_write_compressed(
ptr, pos + REC_MAX_N_FIELDS);
if (trx_undo_left(undo_block, ptr) < 15) {
return 0;
}
ut_ad(fld->field_no < table->n_v_def);
ptr = trx_undo_log_v_idx(undo_block, table,
fld->field_no, ptr,
first_v_col);
if (ptr == NULL) {
return(0);
}
first_v_col = false;
max_v_log_len
= dict_max_v_field_len_store_undo(
table, fld->field_no);
field = static_cast<byte*>(
fld->old_v_val->data);
flen = fld->old_v_val->len;
/* Only log sufficient bytes for index
record update */
if (flen != UNIV_SQL_NULL) {
flen = ut_min(
flen, max_v_log_len);
}
goto store_len;
}
if (UNIV_UNLIKELY(update->is_metadata())) {
ut_ad(pos >= index->first_user_field());
ut_ad(rec_is_metadata(rec, *index));
if (rec_is_alter_metadata(rec, *index)) {
ut_ad(update->is_alter_metadata());
field = rec_offs_n_fields(offsets)
> pos
&& !rec_offs_nth_default(
offsets, pos)
? rec_get_nth_field(
rec, offsets,
pos, &flen)
: index->instant_field_value(
pos - 1, &flen);
if (pos == index->first_user_field()) {
ut_ad(rec_offs_nth_extern(
offsets, pos));
ut_ad(flen == FIELD_REF_SIZE);
goto write_field;
}
col = dict_index_get_nth_col(index,
pos - 1);
} else if (!update->is_alter_metadata()) {
goto get_field;
} else {
/* We are converting an ADD COLUMN
metadata record to an ALTER TABLE
metadata record, with BLOB. Subtract
the missing metadata BLOB field. */
ut_ad(pos > index->first_user_field());
--pos;
goto get_field;
}
} else {
get_field:
col = dict_index_get_nth_col(index, pos);
field = rec_get_nth_cfield(
rec, index, offsets, pos, &flen);
}
write_field:
/* Write field number to undo log */
ptr += mach_write_compressed(ptr, pos);
if (trx_undo_left(undo_block, ptr) < 15) {
return 0;
}
if (rec_offs_n_fields(offsets) > pos
&& rec_offs_nth_extern(offsets, pos)) {
ut_ad(col || pos == index->first_user_field());
ut_ad(col || update->is_alter_metadata());
ut_ad(col
|| rec_is_alter_metadata(rec, *index));
ulint prefix_len = col
? dict_max_field_len_store_undo(
table, col)
: 0;
ut_ad(prefix_len + BTR_EXTERN_FIELD_REF_SIZE
<= sizeof ext_buf);
ptr = trx_undo_page_report_modify_ext(
ptr,
col
&& col->ord_part
&& !ignore_prefix
&& flen < REC_ANTELOPE_MAX_INDEX_COL_LEN
? ext_buf : NULL, prefix_len,
table->space->zip_size(),
&field, &flen, SPATIAL_UNKNOWN);
*type_cmpl_ptr |= TRX_UNDO_UPD_EXTERN;
} else {
store_len:
ptr += mach_write_compressed(ptr, flen);
}
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_block, ptr) < flen) {
return(0);
}
memcpy(ptr, field, flen);
ptr += flen;
}
/* Also record the new value for virtual column */
if (is_virtual) {
field = static_cast<byte*>(fld->new_val.data);
flen = fld->new_val.len;
if (flen != UNIV_SQL_NULL) {
flen = ut_min(
flen, max_v_log_len);
}
if (trx_undo_left(undo_block, ptr) < 15) {
return(0);
}
ptr += mach_write_compressed(ptr, flen);
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_block, ptr)
< flen) {
return(0);
}
memcpy(ptr, field, flen);
ptr += flen;
}
}
}
}
/* Reset the first_v_col, so to put the virtual column undo
version marker again, when we log all the indexed columns */
first_v_col = true;
/*----------------------------------------*/
/* In the case of a delete marking, and also in the case of an update
where any ordering field of any index changes, store the values of all
columns which occur as ordering fields in any index. This info is used
in the purge of old versions where we use it to build and search the
delete marked index records, to look if we can remove them from the
index tree. Note that starting from 4.0.14 also externally stored
fields can be ordering in some index. Starting from 5.2, we no longer
store REC_MAX_INDEX_COL_LEN first bytes to the undo log record,
but we can construct the column prefix fields in the index by
fetching the first page of the BLOB that is pointed to by the
clustered index. This works also in crash recovery, because all pages
(including BLOBs) are recovered before anything is rolled back. */
if (!update || !(cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
byte* old_ptr = ptr;
double mbr[SPDIMS * 2];
mem_heap_t* row_heap = NULL;
if (trx_undo_left(undo_block, ptr) < 5) {
return(0);
}
/* Reserve 2 bytes to write the number of bytes the stored
fields take in this undo record */
ptr += 2;
for (col_no = 0; col_no < dict_table_get_n_cols(table);
col_no++) {
const dict_col_t* col
= dict_table_get_nth_col(table, col_no);
if (!col->ord_part) {
continue;
}
const ulint pos = dict_index_get_nth_col_pos(
index, col_no, NULL);
/* All non-virtual columns must be present in
the clustered index. */
ut_ad(pos != ULINT_UNDEFINED);
const bool is_ext = rec_offs_nth_extern(offsets, pos);
const spatial_status_t spatial_status = is_ext
? dict_col_get_spatial_status(col)
: SPATIAL_NONE;
switch (spatial_status) {
case SPATIAL_UNKNOWN:
ut_ad(0);
/* fall through */
case SPATIAL_MIXED:
case SPATIAL_ONLY:
/* Externally stored spatially indexed
columns will be (redundantly) logged
again, because we did not write the
MBR yet, that is, the previous call to
trx_undo_page_report_modify_ext()
was with SPATIAL_UNKNOWN. */
break;
case SPATIAL_NONE:
if (!update) {
/* This is a DELETE operation. */
break;
}
/* Avoid redundantly logging indexed
columns that were updated. */
for (i = 0; i < update->n_fields; i++) {
const ulint field_no
= upd_get_nth_field(update, i)
->field_no;
if (field_no >= index->n_fields
|| dict_index_get_nth_field(
index, field_no)->col
== col) {
goto already_logged;
}
}
}
if (true) {
/* Write field number to undo log */
if (trx_undo_left(undo_block, ptr) < 5 + 15) {
return(0);
}
ptr += mach_write_compressed(ptr, pos);
/* Save the old value of field */
field = rec_get_nth_cfield(
rec, index, offsets, pos, &flen);
if (is_ext) {
const dict_col_t* col =
dict_index_get_nth_col(
index, pos);
ulint prefix_len =
dict_max_field_len_store_undo(
table, col);
ut_a(prefix_len < sizeof ext_buf);
const ulint zip_size
= table->space->zip_size();
/* If there is a spatial index on it,
log its MBR */
if (spatial_status != SPATIAL_NONE) {
ut_ad(DATA_GEOMETRY_MTYPE(
col->mtype));
trx_undo_get_mbr_from_ext(
mbr, zip_size,
field, &flen);
}
ptr = trx_undo_page_report_modify_ext(
ptr,
flen < REC_ANTELOPE_MAX_INDEX_COL_LEN
&& !ignore_prefix
? ext_buf : NULL, prefix_len,
zip_size,
&field, &flen,
spatial_status);
} else {
ptr += mach_write_compressed(
ptr, flen);
}
if (flen != UNIV_SQL_NULL
&& spatial_status != SPATIAL_ONLY) {
if (trx_undo_left(undo_block, ptr)
< flen) {
return(0);
}
memcpy(ptr, field, flen);
ptr += flen;
}
if (spatial_status != SPATIAL_NONE) {
if (trx_undo_left(undo_block, ptr)
< DATA_MBR_LEN) {
return(0);
}
for (int i = 0; i < SPDIMS * 2;
i++) {
mach_double_write(
ptr, mbr[i]);
ptr += sizeof(double);
}
}
}
already_logged:
continue;
}
for (col_no = 0; col_no < dict_table_get_n_v_cols(table);
col_no++) {
const dict_v_col_t* col
= dict_table_get_nth_v_col(table, col_no);
if (col->m_col.ord_part) {
ulint pos = col_no;
ulint max_v_log_len
= dict_max_v_field_len_store_undo(
table, pos);
/* Write field number to undo log.
Make sure there is enought space in log */
if (trx_undo_left(undo_block, ptr) < 5) {
return(0);
}
pos += REC_MAX_N_FIELDS;
ptr += mach_write_compressed(ptr, pos);
ut_ad(col_no < table->n_v_def);
ptr = trx_undo_log_v_idx(undo_block, table,
col_no, ptr,
first_v_col);
first_v_col = false;
if (!ptr) {
return(0);
}
const dfield_t* vfield = NULL;
if (update) {
ut_ad(!row);
if (update->old_vrow == NULL) {
flen = UNIV_SQL_NULL;
} else {
vfield = dtuple_get_nth_v_field(
update->old_vrow,
col->v_pos);
}
} else if (row) {
vfield = dtuple_get_nth_v_field(
row, col->v_pos);
} else {
ut_ad(0);
}
if (vfield) {
field = static_cast<byte*>(vfield->data);
flen = vfield->len;
} else {
ut_ad(flen == UNIV_SQL_NULL);
}
if (flen != UNIV_SQL_NULL) {
flen = ut_min(
flen, max_v_log_len);
}
ptr += mach_write_compressed(ptr, flen);
switch (flen) {
case 0: case UNIV_SQL_NULL:
break;
default:
if (trx_undo_left(undo_block, ptr)
< flen) {
return(0);
}
memcpy(ptr, field, flen);
ptr += flen;
}
}
}
mach_write_to_2(old_ptr, ulint(ptr - old_ptr));
if (row_heap) {
mem_heap_free(row_heap);
}
}
/*----------------------------------------*/
/* Write pointers to the previous and the next undo log records */
if (trx_undo_left(undo_block, ptr) < 2) {
return(0);
}
mach_write_to_2(ptr, first_free);
const uint16_t new_free = static_cast<uint16_t>(
ptr + 2 - undo_block->page.frame);
mach_write_to_2(undo_block->page.frame + first_free, new_free);
mach_write_to_2(ptr_to_first_free, new_free);
const byte* start = &undo_block->page.frame[first_free + 2];
mtr->undo_append(*undo_block, start, ptr - start);
return(first_free);
}
/**********************************************************************//**
Reads from an undo log update record the system field values of the old
version.
@return remaining part of undo log record after reading these values */
byte*
trx_undo_update_rec_get_sys_cols(
/*=============================*/
const byte* ptr, /*!< in: remaining part of undo
log record after reading
general parameters */
trx_id_t* trx_id, /*!< out: trx id */
roll_ptr_t* roll_ptr, /*!< out: roll ptr */
byte* info_bits) /*!< out: info bits state */
{
/* Read the state of the info bits */
*info_bits = *ptr++;
/* Read the values of the system columns */
*trx_id = mach_u64_read_next_compressed(&ptr);
*roll_ptr = mach_u64_read_next_compressed(&ptr);
return(const_cast<byte*>(ptr));
}
/*******************************************************************//**
Builds an update vector based on a remaining part of an undo log record.
@return remaining part of the record, NULL if an error detected, which
means that the record is corrupted */
byte*
trx_undo_update_rec_get_update(
/*===========================*/
const byte* ptr, /*!< in: remaining part in update undo log
record, after reading the row reference
NOTE that this copy of the undo log record must
be preserved as long as the update vector is
used, as we do NOT copy the data in the
record! */
dict_index_t* index, /*!< in: clustered index */
ulint type, /*!< in: TRX_UNDO_UPD_EXIST_REC,
TRX_UNDO_UPD_DEL_REC, or
TRX_UNDO_DEL_MARK_REC; in the last case,
only trx id and roll ptr fields are added to
the update vector */
trx_id_t trx_id, /*!< in: transaction id from this undo record */
roll_ptr_t roll_ptr,/*!< in: roll pointer from this undo record */
byte info_bits,/*!< in: info bits from this undo record */
mem_heap_t* heap, /*!< in: memory heap from which the memory
needed is allocated */
upd_t** upd) /*!< out, own: update vector */
{
upd_field_t* upd_field;
upd_t* update;
ulint n_fields;
byte* buf;
bool first_v_col = true;
bool is_undo_log = true;
ulint n_skip_field = 0;
ut_a(dict_index_is_clust(index));
if (type != TRX_UNDO_DEL_MARK_REC) {
n_fields = mach_read_next_compressed(&ptr);
} else {
n_fields = 0;
}
*upd = update = upd_create(n_fields + 2, heap);
update->info_bits = info_bits;
/* Store first trx id and roll ptr to update vector */
upd_field = upd_get_nth_field(update, n_fields);
buf = static_cast<byte*>(mem_heap_alloc(heap, DATA_TRX_ID_LEN));
mach_write_to_6(buf, trx_id);
upd_field_set_field_no(upd_field, index->db_trx_id(), index);
dfield_set_data(&(upd_field->new_val), buf, DATA_TRX_ID_LEN);
upd_field = upd_get_nth_field(update, n_fields + 1);
buf = static_cast<byte*>(mem_heap_alloc(heap, DATA_ROLL_PTR_LEN));
trx_write_roll_ptr(buf, roll_ptr);
upd_field_set_field_no(upd_field, index->db_roll_ptr(), index);
dfield_set_data(&(upd_field->new_val), buf, DATA_ROLL_PTR_LEN);
/* Store then the updated ordinary columns to the update vector */
for (ulint i = 0; i < n_fields; i++) {
const byte* field;
uint32_t len, orig_len;
upd_field = upd_get_nth_field(update, i);
uint32_t field_no = mach_read_next_compressed(&ptr);
const bool is_virtual = (field_no >= REC_MAX_N_FIELDS);
if (is_virtual) {
/* If new version, we need to check index list to figure
out the correct virtual column position */
ptr = trx_undo_read_v_idx(
index->table, ptr, first_v_col, &is_undo_log,
&field_no);
first_v_col = false;
/* This column could be dropped or no longer indexed */
if (field_no >= index->n_fields) {
/* Mark this is no longer needed */
upd_field->field_no = REC_MAX_N_FIELDS;
ptr = trx_undo_rec_get_col_val(
ptr, &field, &len, &orig_len);
ptr = trx_undo_rec_get_col_val(
ptr, &field, &len, &orig_len);
n_skip_field++;
continue;
}
upd_field_set_v_field_no(
upd_field, static_cast<uint16_t>(field_no),
index);
} else if (UNIV_UNLIKELY((update->info_bits
& ~REC_INFO_DELETED_FLAG)
== REC_INFO_MIN_REC_FLAG)) {
ut_ad(type == TRX_UNDO_UPD_EXIST_REC);
const uint32_t uf = index->first_user_field();
ut_ad(field_no >= uf);
if (update->info_bits != REC_INFO_MIN_REC_FLAG) {
/* Generic instant ALTER TABLE */
if (field_no == uf) {
upd_field->new_val.type
.metadata_blob_init();
} else if (field_no >= index->n_fields) {
/* This is reachable during
purge if the table was emptied
and converted to the canonical
format on a later ALTER TABLE.
In this case,
row_purge_upd_exist_or_extern()
would only be interested in
freeing any BLOBs that were
updated, that is, the metadata
BLOB above. Other BLOBs in
the metadata record are never
updated; they are for the
initial DEFAULT values of the
instantly added columns, and
they will never change.
Note: if the table becomes
empty during ROLLBACK or is
empty during subsequent ALTER
TABLE, and btr_page_empty() is
called to re-create the root
page without the metadata
record, in that case we should
only free the latest version
of BLOBs in the record,
which purge would never touch. */
field_no = REC_MAX_N_FIELDS;
n_skip_field++;
} else {
dict_col_copy_type(
dict_index_get_nth_col(
index, field_no - 1),
&upd_field->new_val.type);
}
} else {
/* Instant ADD COLUMN...LAST */
dict_col_copy_type(
dict_index_get_nth_col(index,
field_no),
&upd_field->new_val.type);
}
upd_field->field_no = field_no
& dict_index_t::MAX_N_FIELDS;
} else if (field_no < index->n_fields) {
upd_field_set_field_no(upd_field,
static_cast<uint16_t>(field_no),
index);
} else {
ib::error() << "Trying to access update undo rec"
" field " << field_no
<< " in index " << index->name
<< " of table " << index->table->name
<< " but index has only "
<< dict_index_get_n_fields(index)
<< " fields " << BUG_REPORT_MSG
<< ". Run also CHECK TABLE "
<< index->table->name << "."
" n_fields = " << n_fields << ", i = " << i;
ut_ad(0);
*upd = NULL;
return(NULL);
}
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
upd_field->orig_len = static_cast<uint16_t>(orig_len);
if (len == UNIV_SQL_NULL) {
dfield_set_null(&upd_field->new_val);
} else if (len < UNIV_EXTERN_STORAGE_FIELD) {
dfield_set_data(&upd_field->new_val, field, len);
} else {
len -= UNIV_EXTERN_STORAGE_FIELD;
dfield_set_data(&upd_field->new_val, field, len);
dfield_set_ext(&upd_field->new_val);
}
ut_ad(update->info_bits != (REC_INFO_DELETED_FLAG
| REC_INFO_MIN_REC_FLAG)
|| field_no != index->first_user_field()
|| (upd_field->new_val.ext
&& upd_field->new_val.len == FIELD_REF_SIZE));
if (is_virtual) {
upd_field->old_v_val = static_cast<dfield_t*>(
mem_heap_alloc(
heap, sizeof *upd_field->old_v_val));
ptr = trx_undo_rec_get_col_val(
ptr, &field, &len, &orig_len);
if (len == UNIV_SQL_NULL) {
dfield_set_null(upd_field->old_v_val);
} else if (len < UNIV_EXTERN_STORAGE_FIELD) {
dfield_set_data(
upd_field->old_v_val, field, len);
} else {
ut_ad(0);
}
}
}
/* We may have to skip dropped indexed virtual columns.
Also, we may have to trim the update vector of a metadata record
if dict_index_t::clear_instant_alter() was invoked on the table
later, and the number of fields no longer matches. */
if (n_skip_field) {
upd_field_t* d = upd_get_nth_field(update, 0);
const upd_field_t* const end = d + n_fields + 2;
for (const upd_field_t* s = d; s != end; s++) {
if (s->field_no != REC_MAX_N_FIELDS) {
*d++ = *s;
}
}
ut_ad(d + n_skip_field == end);
update->n_fields = d - upd_get_nth_field(update, 0);
}
return(const_cast<byte*>(ptr));
}
/** Report a RENAME TABLE operation.
@param[in,out] trx transaction
@param[in] table table that is being renamed
@param[in,out] block undo page
@param[in,out] mtr mini-transaction
@return byte offset of the undo log record
@retval 0 in case of failure */
static
uint16_t
trx_undo_page_report_rename(trx_t* trx, const dict_table_t* table,
buf_block_t* block, mtr_t* mtr)
{
byte* ptr_first_free = my_assume_aligned<2>(TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_FREE
+ block->page.frame);
const uint16_t first_free = mach_read_from_2(ptr_first_free);
ut_ad(first_free >= TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE);
ut_ad(first_free <= srv_page_size - FIL_PAGE_DATA_END);
byte* const start = block->page.frame + first_free;
size_t len = strlen(table->name.m_name);
const size_t fixed = 2 + 1 + 11 + 11 + 2;
ut_ad(len <= NAME_CHAR_LEN * 5 * 2 + 1);
/* The -10 is used in trx_undo_left() */
compile_time_assert(NAME_CHAR_LEN * 5 * 2 + fixed
+ TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE
< UNIV_PAGE_SIZE_MIN - 10 - FIL_PAGE_DATA_END);
if (trx_undo_left(block, start) < fixed + len) {
ut_ad(first_free > TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_HDR_SIZE);
return 0;
}
byte* ptr = start + 2;
*ptr++ = TRX_UNDO_RENAME_TABLE;
ptr += mach_u64_write_much_compressed(ptr, trx->undo_no);
ptr += mach_u64_write_much_compressed(ptr, table->id);
memcpy(ptr, table->name.m_name, len);
ptr += len;
mach_write_to_2(ptr, first_free);
mach_write_to_2(ptr_first_free, ptr + 2 - block->page.frame);
memcpy(start, ptr_first_free, 2);
mtr->undo_append(*block, start + 2, ptr - start - 2);
return first_free;
}
/** Report a RENAME TABLE operation.
@param[in,out] trx transaction
@param[in] table table that is being renamed
@return DB_SUCCESS or error code */
dberr_t trx_undo_report_rename(trx_t* trx, const dict_table_t* table)
{
ut_ad(!trx->read_only);
ut_ad(trx->id);
ut_ad(!table->is_temporary());
mtr_t mtr;
dberr_t err;
mtr.start();
if (buf_block_t* block = trx_undo_assign(trx, &err, &mtr)) {
trx_undo_t* undo = trx->rsegs.m_redo.undo;
ut_ad(err == DB_SUCCESS);
ut_ad(undo);
for (ut_d(int loop_count = 0);;) {
ut_ad(loop_count++ < 2);
ut_ad(undo->last_page_no
== block->page.id().page_no());
if (uint16_t offset = trx_undo_page_report_rename(
trx, table, block, &mtr)) {
undo->top_page_no = undo->last_page_no;
undo->top_offset = offset;
undo->top_undo_no = trx->undo_no++;
undo->guess_block = block;
ut_ad(!undo->empty());
err = DB_SUCCESS;
break;
} else {
mtr.commit();
mtr.start();
block = trx_undo_add_page(undo, &mtr, &err);
if (!block) {
break;
}
}
}
}
mtr.commit();
return err;
}
TRANSACTIONAL_TARGET ATTRIBUTE_NOINLINE
/** @return whether the transaction holds an exclusive lock on a table */
static bool trx_has_lock_x(const trx_t &trx, dict_table_t& table)
{
ut_ad(!table.is_temporary());
uint32_t n;
#if !defined NO_ELISION && !defined SUX_LOCK_GENERIC
if (xbegin())
{
if (table.lock_mutex_is_locked())
xabort();
n= table.n_lock_x_or_s;
xend();
}
else
#endif
{
table.lock_mutex_lock();
n= table.n_lock_x_or_s;
table.lock_mutex_unlock();
}
/* This thread is executing trx. No other thread can modify our table locks
(only record locks might be created, in an implicit-to-explicit conversion).
Hence, no mutex is needed here. */
if (n)
for (const lock_t *lock : trx.lock.table_locks)
if (lock && lock->type_mode == (LOCK_X | LOCK_TABLE))
return true;
return false;
}
/***********************************************************************//**
Writes information to an undo log about an insert, update, or a delete marking
of a clustered index record. This information is used in a rollback of the
transaction and in consistent reads that must look to the history of this
transaction.
@return DB_SUCCESS or error code */
dberr_t
trx_undo_report_row_operation(
/*==========================*/
que_thr_t* thr, /*!< in: query thread */
dict_index_t* index, /*!< in: clustered index */
const dtuple_t* clust_entry, /*!< in: in the case of an insert,
index entry to insert into the
clustered index; in updates,
may contain a clustered index
record tuple that also contains
virtual columns of the table;
otherwise, NULL */
const upd_t* update, /*!< in: in the case of an update,
the update vector, otherwise NULL */
ulint cmpl_info, /*!< in: compiler info on secondary
index updates */
const rec_t* rec, /*!< in: case of an update or delete
marking, the record in the clustered
index; NULL if insert */
const rec_offs* offsets, /*!< in: rec_get_offsets(rec) */
roll_ptr_t* roll_ptr) /*!< out: DB_ROLL_PTR to the
undo log record */
{
trx_t* trx;
#ifdef UNIV_DEBUG
int loop_count = 0;
#endif /* UNIV_DEBUG */
ut_a(dict_index_is_clust(index));
ut_ad(!update || rec);
ut_ad(!rec || rec_offs_validate(rec, index, offsets));
ut_ad(!srv_read_only_mode);
trx = thr_get_trx(thr);
/* This function must not be invoked during rollback
(of a TRX_STATE_PREPARE transaction or otherwise). */
ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE));
ut_ad(!trx->in_rollback);
/* We must determine if this is the first time when this
transaction modifies this table. */
auto m = trx->mod_tables.emplace(index->table, trx->undo_no);
ut_ad(m.first->second.valid(trx->undo_no));
if (m.second && index->table->is_native_online_ddl()) {
trx->apply_online_log= true;
}
bool bulk = !rec;
if (!bulk) {
/* An UPDATE or DELETE must not be covered by an
earlier start_bulk_insert(). */
ut_ad(!m.first->second.is_bulk_insert());
} else if (m.first->second.is_bulk_insert()) {
/* Above, the emplace() tried to insert an object with
!is_bulk_insert(). Only an explicit start_bulk_insert()
(below) can set the flag. */
ut_ad(!m.second);
/* We already wrote a TRX_UNDO_EMPTY record. */
ut_ad(thr->run_node);
ut_ad(que_node_get_type(thr->run_node) == QUE_NODE_INSERT);
ut_ad(trx->bulk_insert);
return DB_SUCCESS;
} else if (!m.second || !trx->bulk_insert) {
bulk = false;
} else if (index->table->is_temporary()) {
} else if (trx_has_lock_x(*trx, *index->table)
&& index->table->bulk_trx_id == trx->id) {
m.first->second.start_bulk_insert(
index->table,
thd_sql_command(trx->mysql_thd) != SQLCOM_LOAD);
if (dberr_t err = m.first->second.bulk_insert_buffered(
*clust_entry, *index, trx)) {
return err;
}
} else {
bulk = false;
}
mtr_t mtr;
dberr_t err;
mtr.start();
trx_undo_t** pundo;
trx_rseg_t* rseg;
const bool is_temp = index->table->is_temporary();
buf_block_t* undo_block;
if (is_temp) {
mtr.set_log_mode(MTR_LOG_NO_REDO);
rseg = trx->get_temp_rseg();
pundo = &trx->rsegs.m_noredo.undo;
undo_block = trx_undo_assign_low<true>(trx, rseg, pundo,
&mtr, &err);
} else {
ut_ad(!trx->read_only);
ut_ad(trx->id);
pundo = &trx->rsegs.m_redo.undo;
rseg = trx->rsegs.m_redo.rseg;
undo_block = trx_undo_assign_low<false>(trx, rseg, pundo,
&mtr, &err);
}
trx_undo_t* undo = *pundo;
ut_ad((err == DB_SUCCESS) == (undo_block != NULL));
if (UNIV_UNLIKELY(undo_block == NULL)) {
err_exit:
mtr.commit();
return err;
}
ut_ad(undo != NULL);
do {
uint16_t offset = !rec
? trx_undo_page_report_insert(
undo_block, trx, index, clust_entry, &mtr,
bulk)
: trx_undo_page_report_modify(
undo_block, trx, index, rec, offsets, update,
cmpl_info, clust_entry, &mtr);
if (UNIV_UNLIKELY(offset == 0)) {
const uint16_t first_free = mach_read_from_2(
TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE
+ undo_block->page.frame);
memset(undo_block->page.frame + first_free, 0,
(srv_page_size - FIL_PAGE_DATA_END)
- first_free);
if (first_free
== TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE) {
/* The record did not fit on an empty
undo page. Discard the freshly allocated
page and return an error. */
/* When we remove a page from an undo
log, this is analogous to a
pessimistic insert in a B-tree, and we
must reserve the counterpart of the
tree latch, which is the rseg
mutex. We must commit the mini-transaction
first, because it may be holding lower-level
latches, such as SYNC_FSP_PAGE. */
mtr.commit();
mtr.start();
if (is_temp) {
mtr.set_log_mode(MTR_LOG_NO_REDO);
}
rseg->latch.wr_lock(SRW_LOCK_CALL);
err = trx_undo_free_last_page(undo, &mtr);
rseg->latch.wr_unlock();
if (m.second) {
/* We are not going to modify
this table after all. */
trx->mod_tables.erase(m.first);
}
if (err == DB_SUCCESS) {
err = DB_UNDO_RECORD_TOO_BIG;
}
goto err_exit;
} else {
/* Write log for clearing the unused
tail of the undo page. It might
contain some garbage from a previously
written record, and mtr_t::write()
will optimize away writes of unchanged
bytes. Failure to write this caused a
recovery failure when we avoided
reading the undo log page from the
data file and initialized it based on
redo log records (which included the
write of the previous garbage). */
mtr.memset(*undo_block, first_free,
srv_page_size - first_free
- FIL_PAGE_DATA_END, 0);
}
mtr.commit();
} else {
/* Success */
undo->top_page_no = undo_block->page.id().page_no();
mtr.commit();
undo->top_offset = offset;
undo->top_undo_no = trx->undo_no++;
undo->guess_block = undo_block;
ut_ad(!undo->empty());
if (!is_temp) {
trx_mod_table_time_t& time = m.first->second;
ut_ad(time.valid(undo->top_undo_no));
if (!time.is_versioned()
&& index->table->versioned_by_id()
&& (!rec /* INSERT */
|| (update
&& update->affects_versioned()))) {
time.set_versioned(undo->top_undo_no);
}
}
if (!bulk) {
*roll_ptr = trx_undo_build_roll_ptr(
!rec, trx_sys.rseg_id(rseg, !is_temp),
undo->top_page_no, offset);
}
return(DB_SUCCESS);
}
ut_ad(undo_block->page.id().page_no() == undo->last_page_no);
/* We have to extend the undo log by one page */
ut_ad(++loop_count < 2);
mtr.start();
if (is_temp) {
mtr.set_log_mode(MTR_LOG_NO_REDO);
}
undo_block = trx_undo_add_page(undo, &mtr, &err);
DBUG_EXECUTE_IF("ib_err_ins_undo_page_add_failure",
undo_block = NULL;);
} while (UNIV_LIKELY(undo_block != NULL));
if (err != DB_OUT_OF_FILE_SPACE) {
goto err_exit;
}
ib_errf(trx->mysql_thd, IB_LOG_LEVEL_ERROR,
DB_OUT_OF_FILE_SPACE,
//ER_INNODB_UNDO_LOG_FULL,
"No more space left over in %s tablespace for allocating UNDO"
" log pages. Please add new data file to the tablespace or"
" check if filesystem is full or enable auto-extension for"
" the tablespace",
undo->rseg->space == fil_system.sys_space
? "system" : is_temp ? "temporary" : "undo");
goto err_exit;
}
/*============== BUILDING PREVIOUS VERSION OF A RECORD ===============*/
static dberr_t trx_undo_prev_version(const rec_t *rec, dict_index_t *index,
rec_offs *offsets, mem_heap_t *heap,
rec_t **old_vers,
const purge_sys_t::view_guard &check,
ulint v_status,
mem_heap_t *v_heap, dtuple_t **vrow,
const trx_undo_rec_t *undo_rec);
inline const buf_block_t *
purge_sys_t::view_guard::get(const page_id_t id, mtr_t *mtr)
{
buf_block_t *block;
ut_ad(mtr->is_active());
if (!latch)
{
decltype(purge_sys.pages)::const_iterator i= purge_sys.pages.find(id);
if (i != purge_sys.pages.end())
{
block= i->second;
ut_ad(block);
return block;
}
}
block= buf_pool.page_fix(id);
if (block)
{
mtr->memo_push(block, MTR_MEMO_BUF_FIX);
if (latch)
/* In MVCC operations (outside purge tasks), we will refresh the
buf_pool.LRU position. In purge, we expect the page to be freed
soon, at the end of the current batch. */
buf_page_make_young_if_needed(&block->page);
}
return block;
}
/** Build a previous version of a clustered index record. The caller
must hold a latch on the index page of the clustered index record.
@param rec version of a clustered index record
@param index clustered index
@param offsets rec_get_offsets(rec, index)
@param heap memory heap from which the memory needed is allocated
@param old_vers previous version, or NULL if rec is the first inserted
version, or if history data has been deleted (an error),
or if the purge could have removed the version though
it has not yet done so
@param mtr mini-transaction
@param v_status TRX_UNDO_PREV_IN_PURGE, ...
@param v_heap memory heap used to create vrow dtuple if it is not yet
created. This heap diffs from "heap" above in that it could be
prebuilt->old_vers_heap for selection
@param vrow virtual column info, if any
@return error code
@retval DB_SUCCESS if previous version was successfully built,
or if it was an insert or the undo record refers to the table before rebuild
@retval DB_MISSING_HISTORY if the history is missing */
TRANSACTIONAL_TARGET
dberr_t trx_undo_prev_version_build(const rec_t *rec, dict_index_t *index,
rec_offs *offsets, mem_heap_t *heap,
rec_t **old_vers, mtr_t *mtr,
ulint v_status,
mem_heap_t *v_heap, dtuple_t **vrow)
{
ut_ad(!index->table->is_temporary());
ut_ad(rec_offs_validate(rec, index, offsets));
const roll_ptr_t roll_ptr= row_get_rec_roll_ptr(rec, index, offsets);
*old_vers= nullptr;
if (trx_undo_roll_ptr_is_insert(roll_ptr))
/* The record rec is the first inserted version */
return DB_SUCCESS;
ut_ad(roll_ptr < 1ULL << 55);
ut_ad(uint16_t(roll_ptr) >= TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE);
ut_ad(uint32_t(roll_ptr >> 16) >= FSP_FIRST_INODE_PAGE_NO);
const trx_id_t rec_trx_id= row_get_rec_trx_id(rec, index, offsets);
ut_ad(!index->table->skip_alter_undo);
mariadb_increment_undo_records_read();
const auto savepoint= mtr->get_savepoint();
dberr_t err= DB_MISSING_HISTORY;
purge_sys_t::view_guard check{v_status == TRX_UNDO_CHECK_PURGE_PAGES
? purge_sys_t::view_guard::PURGE
: v_status == TRX_UNDO_CHECK_PURGEABILITY
? purge_sys_t::view_guard::VIEW
: purge_sys_t::view_guard::END_VIEW};
if (!check.view().changes_visible(rec_trx_id))
{
trx_undo_rec_t *undo_rec= nullptr;
static_assert(ROLL_PTR_RSEG_ID_POS == 48, "");
static_assert(ROLL_PTR_PAGE_POS == 16, "");
if (const buf_block_t *undo_page=
check.get(page_id_t{trx_sys.rseg_array[(roll_ptr >> 48) & 0x7f].
space->id,
uint32_t(roll_ptr >> 16)}, mtr))
{
static_assert(ROLL_PTR_BYTE_POS == 0, "");
const uint16_t offset{uint16_t(roll_ptr)};
undo_rec= undo_page->page.frame + offset;
const size_t end= mach_read_from_2(undo_rec);
if (UNIV_UNLIKELY(end > offset &&
end < srv_page_size - FIL_PAGE_DATA_END))
err= trx_undo_prev_version(rec, index, offsets, heap,
old_vers, check, v_status, v_heap, vrow,
undo_rec);
}
}
mtr->rollback_to_savepoint(savepoint);
return err;
}
static dberr_t trx_undo_prev_version(const rec_t *rec, dict_index_t *index,
rec_offs *offsets, mem_heap_t *heap,
rec_t **old_vers,
const purge_sys_t::view_guard &check,
ulint v_status,
mem_heap_t *v_heap, dtuple_t **vrow,
const trx_undo_rec_t *undo_rec)
{
byte type, cmpl_info;
bool dummy_extern;
undo_no_t undo_no;
table_id_t table_id;
const byte *ptr =
trx_undo_rec_get_pars(undo_rec, &type, &cmpl_info,
&dummy_extern, &undo_no, &table_id);
if (table_id != index->table->id) {
/* The table should have been rebuilt, but purge has
not yet removed the undo log records for the
now-dropped old table (table_id). */
return DB_SUCCESS;
}
trx_id_t trx_id;
roll_ptr_t roll_ptr;
byte info_bits;
ptr = trx_undo_update_rec_get_sys_cols(ptr, &trx_id, &roll_ptr,
&info_bits);
/* (a) If a clustered index record version is such that the
trx id stamp in it is bigger than purge_sys.view, then the
BLOBs in that version are known to exist (the purge has not
progressed that far);
(b) if the version is the first version such that trx id in it
is less than purge_sys.view, and it is not delete-marked,
then the BLOBs in that version are known to exist (the purge
cannot have purged the BLOBs referenced by that version
yet).
This function does not fetch any BLOBs. The callers might, by
possibly invoking row_ext_create() via row_build(). However,
they should have all needed information in the *old_vers
returned by this function. This is because *old_vers is based
on the transaction undo log records. The function
trx_undo_page_fetch_ext() will write BLOB prefixes to the
transaction undo log that are at least as long as the longest
possible column prefix in a secondary index. Thus, secondary
index entries for *old_vers can be constructed without
dereferencing any BLOB pointers. */
ptr = trx_undo_rec_skip_row_ref(ptr, index);
upd_t* update;
ptr = trx_undo_update_rec_get_update(ptr, index, type, trx_id,
roll_ptr, info_bits,
heap, &update);
ut_a(ptr);
byte* buf;
if (row_upd_changes_field_size_or_external(index, offsets, update)) {
/* We should confirm the existence of disowned external data,
if the previous version record is delete marked. If the trx_id
of the previous record is seen by purge view, we should treat
it as missing history, because the disowned external data
might be purged already.
The inherited external data (BLOBs) can be freed (purged)
after trx_id was committed, provided that no view was started
before trx_id. If the purge view can see the committed
delete-marked record by trx_id, no transactions need to access
the BLOB. */
if (update->info_bits & REC_INFO_DELETED_FLAG
&& check.view().changes_visible(trx_id)) {
return DB_SUCCESS;
}
/* We have to set the appropriate extern storage bits in the
old version of the record: the extern bits in rec for those
fields that update does NOT update, as well as the bits for
those fields that update updates to become externally stored
fields. Store the info: */
dtuple_t* entry = row_rec_to_index_entry(rec, index, offsets,
heap);
/* The page containing the clustered index record
corresponding to entry is latched. Thus the
following call is safe. */
if (!row_upd_index_replace_new_col_vals(entry, *index, update,
heap)) {
return (v_status & TRX_UNDO_PREV_IN_PURGE)
? DB_MISSING_HISTORY : DB_CORRUPTION;
}
/* Get number of externally stored columns in updated record */
const ulint n_ext = index->is_primary()
? dtuple_get_n_ext(entry) : 0;
buf = static_cast<byte*>(mem_heap_alloc(
heap, rec_get_converted_size(index, entry, n_ext)));
*old_vers = rec_convert_dtuple_to_rec(buf, index,
entry, n_ext);
} else {
buf = static_cast<byte*>(mem_heap_alloc(
heap, rec_offs_size(offsets)));
*old_vers = rec_copy(buf, rec, offsets);
rec_offs_make_valid(*old_vers, index, true, offsets);
rec_set_bit_field_1(*old_vers, update->info_bits,
rec_offs_comp(offsets)
? REC_NEW_INFO_BITS : REC_OLD_INFO_BITS,
REC_INFO_BITS_MASK, REC_INFO_BITS_SHIFT);
for (ulint i = 0; i < update->n_fields; i++) {
const upd_field_t* uf = upd_get_nth_field(update, i);
if (upd_fld_is_virtual_col(uf)) {
/* There are no virtual columns in
a clustered index record. */
continue;
}
const ulint n = uf->field_no;
ut_ad(!dfield_is_ext(&uf->new_val)
== !rec_offs_nth_extern(offsets, n));
ut_ad(!rec_offs_nth_default(offsets, n));
if (UNIV_UNLIKELY(dfield_is_null(&uf->new_val))) {
if (rec_offs_nth_sql_null(offsets, n)) {
ut_ad(index->table->is_instant());
ut_ad(n >= index->n_core_fields);
continue;
}
ut_ad(!index->table->not_redundant());
ulint l = rec_get_1byte_offs_flag(*old_vers)
? (n + 1) : (n + 1) * 2;
byte* b = *old_vers - REC_N_OLD_EXTRA_BYTES
- l;
*b= byte(*b | REC_1BYTE_SQL_NULL_MASK);
compile_time_assert(REC_1BYTE_SQL_NULL_MASK << 8
== REC_2BYTE_SQL_NULL_MASK);
continue;
}
ulint len;
memcpy(rec_get_nth_field(*old_vers, offsets, n, &len),
uf->new_val.data, uf->new_val.len);
if (UNIV_UNLIKELY(len != uf->new_val.len)) {
ut_ad(len == UNIV_SQL_NULL);
ut_ad(!rec_offs_comp(offsets));
ut_ad(uf->new_val.len
== rec_get_nth_field_size(rec, n));
ulint l = rec_get_1byte_offs_flag(*old_vers)
? (n + 1) : (n + 1) * 2;
*(*old_vers - REC_N_OLD_EXTRA_BYTES - l)
&= byte(~REC_1BYTE_SQL_NULL_MASK);
}
}
}
/* Set the old value (which is the after image of an update) in the
update vector to dtuple vrow */
if (v_status & TRX_UNDO_GET_OLD_V_VALUE) {
row_upd_replace_vcol((dtuple_t*)*vrow, index->table, update,
false, nullptr, nullptr);
}
#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
rec_offs offsets_dbg[REC_OFFS_NORMAL_SIZE];
rec_offs_init(offsets_dbg);
ut_a(!rec_offs_any_null_extern(
*old_vers, rec_get_offsets(*old_vers, index, offsets_dbg,
index->n_core_fields,
ULINT_UNDEFINED, &heap)));
#endif // defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
if (vrow && !(cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
if (!(*vrow)) {
*vrow = dtuple_create_with_vcol(
v_heap ? v_heap : heap,
dict_table_get_n_cols(index->table),
dict_table_get_n_v_cols(index->table));
dtuple_init_v_fld(*vrow);
}
ut_ad(index->table->n_v_cols);
trx_undo_read_v_cols(index->table, ptr, *vrow,
v_status & TRX_UNDO_PREV_IN_PURGE);
}
return DB_SUCCESS;
}
/** Read virtual column value from undo log
@param[in] table the table
@param[in] ptr undo log pointer
@param[in,out] row the dtuple to fill
@param[in] in_purge whether this is called by purge */
void
trx_undo_read_v_cols(
const dict_table_t* table,
const byte* ptr,
dtuple_t* row,
bool in_purge)
{
const byte* end_ptr;
bool first_v_col = true;
bool is_undo_log = true;
end_ptr = ptr + mach_read_from_2(ptr);
ptr += 2;
while (ptr < end_ptr) {
dfield_t* dfield;
const byte* field;
uint32_t field_no, len, orig_len;
field_no = mach_read_next_compressed(
const_cast<const byte**>(&ptr));
const bool is_virtual = (field_no >= REC_MAX_N_FIELDS);
if (is_virtual) {
ptr = trx_undo_read_v_idx(
table, ptr, first_v_col, &is_undo_log,
&field_no);
first_v_col = false;
}
ptr = trx_undo_rec_get_col_val(
ptr, &field, &len, &orig_len);
/* The virtual column is no longer indexed or does not exist.
This needs to put after trx_undo_rec_get_col_val() so the
undo ptr advances */
if (field_no == FIL_NULL) {
ut_ad(is_virtual);
continue;
}
if (is_virtual) {
dict_v_col_t* vcol = dict_table_get_nth_v_col(
table, field_no);
dfield = dtuple_get_nth_v_field(row, vcol->v_pos);
if (!in_purge
|| dfield_get_type(dfield)->mtype == DATA_MISSING) {
dict_col_copy_type(
&vcol->m_col,
dfield_get_type(dfield));
dfield_set_data(dfield, field, len);
}
}
}
ut_ad(ptr == end_ptr);
}
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