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polardbxengine/storage/innobase/trx/trx0rec.cc

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/*****************************************************************************
Copyright (c) 1996, 2019, Oracle and/or its affiliates. All Rights Reserved.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License, version 2.0, as published by the
Free Software Foundation.
This program is also distributed with certain software (including but not
limited to OpenSSL) that is licensed under separate terms, as designated in a
particular file or component or in included license documentation. The authors
of MySQL hereby grant you an additional permission to link the program and
your derivative works with the separately licensed software that they have
included with MySQL.
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, version 2.0,
for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*****************************************************************************/
/** @file trx/trx0rec.cc
Transaction undo log record
Created 3/26/1996 Heikki Tuuri
*******************************************************/
#include "trx0rec.h"
#include <sys/types.h>
#include "fsp0fsp.h"
#include "mach0data.h"
#include "mtr0log.h"
#include "trx0undo.h"
#ifndef UNIV_HOTBACKUP
#include "dict0dict.h"
#include "fsp0sysspace.h"
#include "lob0index.h"
#include "lob0inf.h"
#include "lob0lob.h"
#include "que0que.h"
#include "read0read.h"
#include "row0ext.h"
#include "row0mysql.h"
#include "row0row.h"
#include "row0upd.h"
#include "trx0purge.h"
#include "trx0rseg.h"
#include "ut0mem.h"
#include "my_dbug.h"
#include "lizard0undo.h"
#include "lizard0row.h"
namespace dd {
class Spatial_reference_system;
}
/*=========== UNDO LOG RECORD CREATION AND DECODING ====================*/
/** Writes the mtr log entry of the inserted undo log record on the undo log
page. */
UNIV_INLINE
void trx_undof_page_add_undo_rec_log(
page_t *undo_page, /*!< in: undo log page */
ulint old_free, /*!< in: start offset of the inserted entry */
ulint new_free, /*!< in: end offset of the entry */
mtr_t *mtr) /*!< in: mtr */
{
byte *log_ptr;
const byte *log_end;
ulint len;
log_ptr = mlog_open(mtr, 11 + 13 + MLOG_BUF_MARGIN);
if (log_ptr == NULL) {
return;
}
log_end = &log_ptr[11 + 13 + MLOG_BUF_MARGIN];
log_ptr = mlog_write_initial_log_record_fast(undo_page, MLOG_UNDO_INSERT,
log_ptr, mtr);
len = new_free - old_free - 4;
mach_write_to_2(log_ptr, len);
log_ptr += 2;
if (log_ptr + len <= log_end) {
memcpy(log_ptr, undo_page + old_free + 2, len);
mlog_close(mtr, log_ptr + len);
} else {
mlog_close(mtr, log_ptr);
mlog_catenate_string(mtr, undo_page + old_free + 2, len);
}
}
#endif /* !UNIV_HOTBACKUP */
/** Parses a redo log record of adding an undo log record.
@return end of log record or NULL */
byte *trx_undo_parse_add_undo_rec(byte *ptr, /*!< in: buffer */
byte *end_ptr, /*!< in: buffer end */
page_t *page) /*!< in: page or NULL */
{
ulint len;
byte *rec;
ulint first_free;
if (end_ptr < ptr + 2) {
return (NULL);
}
len = mach_read_from_2(ptr);
ptr += 2;
if (end_ptr < ptr + len) {
return (NULL);
}
if (page == NULL) {
return (ptr + len);
}
first_free = mach_read_from_2(page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE);
rec = page + first_free;
mach_write_to_2(rec, first_free + 4 + len);
mach_write_to_2(rec + 2 + len, first_free);
mach_write_to_2(page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE,
first_free + 4 + len);
ut_memcpy(rec + 2, ptr, len);
return (ptr + len);
}
#ifndef UNIV_HOTBACKUP
/** Calculates the free space left for extending an undo log record.
@return bytes left */
UNIV_INLINE
ulint trx_undo_left(const page_t *page, /*!< in: undo log page */
const byte *ptr) /*!< in: pointer to page */
{
/* The '- 10' is a safety margin, in case we have some small
calculation error below */
#ifdef UNIV_DEBUG
ut_ad(ptr >= page);
size_t diff = ptr - page;
size_t max_free = UNIV_PAGE_SIZE - 10 - FIL_PAGE_DATA_END;
ut_ad(diff < UNIV_PAGE_SIZE);
ut_ad(diff <= max_free);
#endif /* UNIV_DEBUG */
return (UNIV_PAGE_SIZE - (ptr - page) - 10 - FIL_PAGE_DATA_END);
}
size_t trx_undo_max_free_space() {
/* Starting from an empty undo page. The following calculation is based
on what free space is got from trx_undo_reuse_cached(), trx_undo_create()
and trx_undo_left(). Current simplified free_space would be
UNIV_PAGE_SIZE - 290. */
size_t free_space =
UNIV_PAGE_SIZE - (TRX_UNDO_SEG_HDR + TRX_UNDO_SEG_HDR_SIZE +
TRX_UNDO_LOG_XA_HDR_SIZE + FIL_PAGE_DATA_END + 10);
/* Undo number, table id, undo log type and pointer to next.
Also refer to the beginning of trx_undo_page_report_insert() */
free_space -= (11 + 11 + 1 + 2);
/* For simplification, the max record length should be
UNIV_PAGE_SIZE - 290 - 25 = UNIV_PAGE_SIZE - 315. */
return (free_space);
}
/** 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 ulint trx_undo_page_set_next_prev_and_add(
page_t *undo_page, /*!< 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 */
{
ulint first_free; /*!< offset within undo_page */
ulint end_of_rec; /*!< offset within undo_page */
byte *ptr_to_first_free;
/* pointer within undo_page
that points to the next free
offset value within undo_page.*/
ut_ad(ptr > undo_page);
ut_ad(ptr < undo_page + UNIV_PAGE_SIZE);
if (UNIV_UNLIKELY(trx_undo_left(undo_page, ptr) < 2)) {
return (0);
}
ptr_to_first_free = undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE;
first_free = mach_read_from_2(ptr_to_first_free);
/* Write offset of the previous undo log record */
mach_write_to_2(ptr, first_free);
ptr += 2;
end_of_rec = ptr - undo_page;
/* Write offset of the next undo log record */
mach_write_to_2(undo_page + first_free, end_of_rec);
/* Update the offset to first free undo record */
mach_write_to_2(ptr_to_first_free, end_of_rec);
/* Write this log entry to the UNDO log */
trx_undof_page_add_undo_rec_log(undo_page, first_free, end_of_rec, mtr);
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;
/** Decide if the following undo log record is a multi-value virtual column
@param[in] undo_rec undo log record
@return true if this is a multi-value virtual column log, otherwise false */
bool trx_undo_rec_is_multi_value(const byte *undo_rec) {
return (Multi_value_logger::is_multi_value_log(undo_rec));
}
/** Write virtual column index info (index id and column position in index)
to the undo log
@param[in,out] undo_page 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(page_t *undo_page, 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);
ulint n_idx = vcol->v_indexes->size();
byte *old_ptr;
ut_ad(n_idx > 0);
/* Size to reserve, max 5 bytes for each index id and position, plus
5 bytes for num of indexes, 2 bytes for write total length.
1 byte for undo log record format version marker */
ulint size = n_idx * (5 + 5) + 5 + 2 + (first_v_col ? 1 : 0);
if (trx_undo_left(undo_page, ptr) < size) {
return (NULL);
}
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);
dict_v_idx_list::iterator it;
for (it = vcol->v_indexes->begin(); it != vcol->v_indexes->end(); ++it) {
dict_v_idx_t v_index = *it;
ptr += mach_write_compressed(ptr, static_cast<ulint>(v_index.index->id));
ptr += mach_write_compressed(ptr, v_index.nth_field);
}
mach_write_to_2(old_ptr, 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 ULINT_UNDEFINED
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, ulint *col_pos) {
ulint len = mach_read_from_2(ptr);
const byte *old_ptr = ptr;
*col_pos = ULINT_UNDEFINED;
ptr += 2;
ulint num_idx = mach_read_next_compressed(&ptr);
ut_ad(num_idx > 0);
const dict_index_t *clust_index = table->first_index();
for (ulint i = 0; i < num_idx; i++) {
space_index_t id = mach_read_next_compressed(&ptr);
ulint pos = mach_read_next_compressed(&ptr);
const dict_index_t *index = clust_index->next();
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 = index->get_col(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 = index->next();
}
}
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[in,out] field_no the column number
@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,
ulint *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);
}
/** Store the multi-value column information for undo log
@param[in,out] undo_page undo page to store the information
@param[in] vfield multi-value field information
@param[in,out] ptr pointer where to store the information
@return true if stored successfully, false if space is not enough */
static bool trx_undo_store_multi_value(page_t *undo_page,
const dfield_t *vfield, byte **ptr) {
Multi_value_logger mv_logger(
static_cast<multi_value_data *>(dfield_get_data(vfield)),
dfield_get_len(vfield));
uint32_t log_len = mv_logger.get_log_len(false);
if (trx_undo_left(undo_page, *ptr) < log_len) {
return (false);
}
mv_logger.log(ptr);
return (true);
}
/** Reports in the undo log of an insert of virtual columns.
@param[in] undo_page 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(page_t *undo_page,
dict_table_t *table,
const dtuple_t *row, byte **ptr) {
byte *start = *ptr;
bool first_v_col = true;
if (trx_undo_left(undo_page, *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++) {
dfield_t *vfield = NULL;
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_page, *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_page, table, col_no, *ptr, first_v_col);
first_v_col = false;
if (*ptr == NULL) {
return (false);
}
vfield = dtuple_get_nth_v_field(row, col->v_pos);
ulint flen = vfield->len;
if (col->m_col.is_multi_value()) {
bool suc = trx_undo_store_multi_value(undo_page, vfield, ptr);
if (!suc) {
return (false);
}
} else if (flen != UNIV_SQL_NULL) {
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_page, *ptr) < flen + 5) {
return (false);
}
*ptr += mach_write_compressed(*ptr, flen);
ut_memcpy(*ptr, vfield->data, flen);
*ptr += flen;
} else {
if (trx_undo_left(undo_page, *ptr) < 5) {
return (false);
}
*ptr += mach_write_compressed(*ptr, flen);
}
}
}
/* Always mark the end of the log with 2 bytes length field */
mach_write_to_2(start, *ptr - start);
return (true);
}
/** Reports in the undo log of an insert of a clustered index record.
@return offset of the inserted entry on the page if succeed, 0 if fail */
static ulint trx_undo_page_report_insert(
page_t *undo_page, /*!< in: undo log page */
trx_t *trx, /*!< in: transaction */
dict_index_t *index, /*!< in: clustered index */
const dtuple_t *clust_entry, /*!< in: index entry which will be
inserted to the clustered index */
mtr_t *mtr) /*!< in: mtr */
{
ulint first_free;
byte *ptr;
ulint i;
ut_ad(index->is_clustered());
ut_ad(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_TYPE) ==
TRX_UNDO_INSERT);
first_free =
mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE);
ptr = undo_page + first_free;
ut_ad(first_free <= UNIV_PAGE_SIZE);
if (trx_undo_left(undo_page, 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);
/*----------------------------------------*/
/* Store then the fields required to uniquely determine the record
to be inserted in the clustered index */
for (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_page, ptr) < 5) {
return (0);
}
ptr += mach_write_compressed(ptr, flen);
if (flen != UNIV_SQL_NULL && flen != 0) {
if (trx_undo_left(undo_page, ptr) < flen) {
return (0);
}
ut_memcpy(ptr, dfield_get_data(field), flen);
ptr += flen;
}
}
if (index->table->n_v_cols) {
if (!trx_undo_report_insert_virtual(undo_page, index->table, clust_entry,
&ptr)) {
return (0);
}
}
return (trx_undo_page_set_next_prev_and_add(undo_page, ptr, mtr));
}
/** Reads from an undo log record the general parameters.
@return remaining part of undo log record after reading these values */
byte *trx_undo_rec_get_pars(
trx_undo_rec_t *undo_rec, /*!< in: undo log record */
ulint *type, /*!< out: undo record type:
TRX_UNDO_INSERT_REC, ... */
ulint *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 */
type_cmpl_t &type_cmpl) /*!< out: type compilation info */
{
const byte *ptr;
ptr = undo_rec + 2;
ptr = type_cmpl.read(ptr);
*updated_extern = type_cmpl.is_lob_updated();
*type = type_cmpl.type_info();
*cmpl_info = type_cmpl.cmpl_info();
if (type_cmpl.is_lob_undo()) {
/* Reading the new 1-byte undo record flag. */
uint8_t undo_rec_flags = 0x00;
undo_rec_flags = mach_read_from_1(ptr);
ptr++;
ut_a(undo_rec_flags == 0x00);
}
*undo_no = mach_read_next_much_compressed(&ptr);
*table_id = mach_read_next_much_compressed(&ptr);
return (const_cast<byte *>(ptr));
}
/** Reads from an undo log record the table ID
@param[in] undo_rec Undo log record
@return the table ID */
table_id_t trx_undo_rec_get_table_id(const trx_undo_rec_t *undo_rec) {
const byte *ptr = undo_rec + 2;
uint8_t type_cmpl = mach_read_from_1(ptr);
const bool blob_undo = type_cmpl & TRX_UNDO_MODIFY_BLOB;
if (blob_undo) {
/* The next record offset takes 2 bytes + 1 byte for
type_cmpl flag + 1 byte for the new flag. Total 4 bytes.
The new flag is currently unused and is available for
future use. */
ptr = undo_rec + 4;
} else {
ptr = undo_rec + 3;
}
/* Skip the UNDO number */
mach_read_next_much_compressed(&ptr);
/* Read the table ID */
return (mach_read_next_much_compressed(&ptr));
}
/** Read from an undo log record of a multi-value virtual column.
@param[in] ptr pointer to remaining part of the undo record
@param[in,out] field stored field, nullptr if the col is no longer
indexed or existing, in the latter case,
this function will only skip the log
@param[in,out] heap memory heap
@return remaining part of undo log record after reading these values */
const byte *trx_undo_rec_get_multi_value(const byte *ptr, dfield_t *field,
mem_heap_t *heap) {
if (field == nullptr) {
return (ptr + Multi_value_logger::read_log_len(ptr));
}
return (Multi_value_logger::read(ptr, field, heap));
}
/** Read from an undo log record a non-virtual column value.
@param[in,out] ptr pointer to remaining part of the undo record
@param[in,out] field stored field
@param[in,out] len length of the field, or UNIV_SQL_NULL
@param[in,out] 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 */
byte *trx_undo_rec_get_col_val(const byte *ptr, const byte **field, ulint *len,
ulint *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 (const_cast<byte *>(ptr));
}
/** Builds a row reference from an undo log record.
@return pointer to remaining part of undo record */
byte *trx_undo_rec_get_row_ref(
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 */
dtuple_t **ref, /*!< out, own: row reference */
mem_heap_t *heap) /*!< in: memory heap from which the memory
needed is allocated */
{
ulint ref_len;
ulint i;
ut_ad(index && ptr && ref && heap);
ut_a(index->is_clustered());
ref_len = dict_index_get_n_unique(index);
*ref = dtuple_create(heap, ref_len);
dict_index_copy_types(*ref, index, ref_len);
for (i = 0; i < ref_len; i++) {
dfield_t *dfield;
const byte *field;
ulint len;
ulint orig_len;
dfield = dtuple_get_nth_field(*ref, i);
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
dfield_set_data(dfield, field, len);
}
return (ptr);
}
/** Skips a row reference from an undo log record.
@return pointer to remaining part of undo record */
static byte *trx_undo_rec_skip_row_ref(
byte *ptr, /*!< in: remaining part in update undo log
record, at the start of the row reference */
const dict_index_t *index) /*!< in: clustered index */
{
ulint ref_len;
ulint i;
ut_ad(index && ptr);
ut_a(index->is_clustered());
ref_len = dict_index_get_n_unique(index);
for (i = 0; i < ref_len; i++) {
const byte *field;
ulint len;
ulint orig_len;
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
}
return (ptr);
}
#ifdef UNIV_DEBUG
#define trx_undo_page_fetch_ext(trx, index, ext_buf, prefix_len, page_size, \
field, is_sdi, len) \
trx_undo_page_fetch_ext_func(trx, index, ext_buf, prefix_len, page_size, \
field, is_sdi, len)
#define trx_undo_page_report_modify_ext(trx, index, ptr, ext_buf, prefix_len, \
page_size, field, len, is_sdi, \
spatial_status) \
trx_undo_page_report_modify_ext_func(trx, index, ptr, ext_buf, prefix_len, \
page_size, field, len, is_sdi, \
spatial_status)
#else /* UNIV_DEBUG */
#define trx_undo_page_fetch_ext(trx, index, ext_buf, prefix_len, page_size, \
field, is_sdi, len) \
trx_undo_page_fetch_ext_func(trx, index, ext_buf, prefix_len, page_size, \
field, len)
#define trx_undo_page_report_modify_ext(trx, index, ptr, ext_buf, prefix_len, \
page_size, field, len, is_sdi, \
spatial_status) \
trx_undo_page_report_modify_ext_func(trx, index, ptr, ext_buf, prefix_len, \
page_size, field, len, spatial_status)
#endif /* UNIV_DEBUG */
/** 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[in] trx transaction object
@param[in] index the clustered index object
@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] page_size page size
@param[in] field an externally stored column
@param[in] is_sdi true for SDI indexes
@param[in,out] len input: length of field; output: used length of
ext_buf
@return ext_buf */
static byte *trx_undo_page_fetch_ext_func(trx_t *trx, dict_index_t *index,
byte *ext_buf, ulint prefix_len,
const page_size_t &page_size,
const byte *field,
#ifdef UNIV_DEBUG
bool is_sdi,
#endif /* UNIV_DEBUG */
ulint *len) {
/* Fetch the BLOB. */
ulint ext_len = lob::btr_copy_externally_stored_field_prefix(
trx, index, ext_buf, prefix_len, page_size, field, is_sdi, *len);
#ifdef UNIV_DEBUG
if (ext_len == 0) {
byte *field_ref = const_cast<byte *>(field) + (*len) - lob::ref_t::SIZE;
lob::ref_t ref(field_ref);
lob::ref_mem_t ref_mem;
ref.parse(ref_mem);
lob::print(trx, index, std::cout, ref, true);
}
#endif /* UNIV_DEBUG */
/* BLOBs should always be nonempty. */
ut_a(ext_len > 0);
/* 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[in] trx transaction object
@param[in] index the clustered index object
@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] page_size page size
@param[in,out] field the locally stored part of the externally
stored column
@param[in,out] len length of field, in bytes
@param[in] is_sdi true for SDI indexes
@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_func(
trx_t *trx, dict_index_t *index, byte *ptr, byte *ext_buf, ulint prefix_len,
const page_size_t &page_size, const byte **field, ulint *len,
#ifdef UNIV_DEBUG
bool is_sdi,
#endif /* UNIV_DEBUG */
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 |= 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(trx, index, ext_buf, prefix_len, page_size,
*field, is_sdi, 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[in] trx transaction object
@param[in] index the clustered index object
@param[out] mbr MBR to fill
@param[in] page_size table pagesize
@param[in] field field contain the geometry data
@param[in,out] len length of field, in bytes
@param[in] srs Spatial reference system of R-tree.
*/
static void trx_undo_get_mbr_from_ext(trx_t *trx, dict_index_t *index,
double *mbr, const page_size_t &page_size,
const byte *field, ulint *len,
const dd::Spatial_reference_system *srs) {
uchar *dptr = NULL;
ulint dlen;
mem_heap_t *heap = mem_heap_create(100);
dptr = lob::btr_copy_externally_stored_field(
trx, index, &dlen, nullptr, field, page_size, *len, false, 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 {
get_mbr_from_store(srs, dptr, static_cast<uint>(dlen), SPDIMS, mbr,
nullptr);
}
mem_heap_free(heap);
}
static const byte *trx_undo_read_blob_update(const byte *undo_ptr,
upd_field_t *uf,
lob::undo_vers_t *lob_undo) {
DBUG_TRACE;
/* Read one byte of flags. */
uint8_t flag = *undo_ptr;
ut_a(flag == 0x00);
undo_ptr++;
const ulint field_no = uf->field_no;
/* Read the size of the vector. */
ulint N = mach_read_next_compressed(&undo_ptr);
if (N == 0) {
return undo_ptr;
}
/* Read the LOB first page number*/
uf->lob_first_page_no = mach_read_next_compressed(&undo_ptr);
uf->lob_version = mach_read_next_compressed(&undo_ptr);
uf->last_trx_id = mach_read_next_compressed(&undo_ptr);
uf->last_undo_no = mach_read_next_compressed(&undo_ptr);
for (size_t i = 0; i < N; ++i) {
Lob_diff lob_diff(uf->heap);
lob::undo_seq_t *lob_seq = nullptr;
lob::undo_data_t lob_undo_data;
if (lob_undo != nullptr) {
lob_seq = lob_undo->get_undo_sequence(field_no);
}
/* Read the offset. */
undo_ptr = lob_diff.read_offset(undo_ptr);
lob_undo_data.m_offset = lob_diff.m_offset;
/* Read the length. */
undo_ptr = lob_diff.read_length(undo_ptr);
/* Read the old data. */
lob_diff.set_old_data(undo_ptr);
/* Copy the data only if the lob_undo is not null. */
if (lob_seq != nullptr) {
undo_ptr = lob_undo_data.copy_old_data(undo_ptr, lob_diff.m_length);
} else {
undo_ptr += lob_diff.m_length;
}
lob_undo_data.m_version = uf->lob_version;
lob_undo_data.m_page_no = uf->lob_first_page_no;
if (lob_seq != nullptr) {
lob_seq->m_field_no = field_no;
lob_seq->push_back(lob_undo_data);
}
/* Read the number of LOB index entries modified. */
ulint n_entry = mach_read_next_compressed(&undo_ptr);
ut_ad(n_entry == 1 || n_entry == 2);
for (size_t i = 0; i < n_entry; ++i) {
lob_index_diff_t idx_diff;
/* Read the modifier trx id of the LOB index entry. */
idx_diff.m_modifier_trxid = mach_read_next_compressed(&undo_ptr);
/* Write the modifier trx undo_no of the LOB index entry. */
idx_diff.m_modifier_undo_no = mach_read_next_compressed(&undo_ptr);
lob_diff.m_idx_diffs->push_back(idx_diff);
}
uf->push_lob_diff(lob_diff);
DBUG_LOG("lob", lob_diff);
}
return undo_ptr;
}
/** Write the partial update information about LOBs to the undo log record.
@param[in] undo_page the undo page
@param[in] index the clustered index where LOBs are modified.
@param[in] undo_ptr the location within undo page where next
part of undo record is to be written.
@param[in] field the LOB data
@param[in] flen length of LOB data in bytes
@param[in] update the update vector containing partial update
information on LOBs.
@param[in] fld the field to which the LOB belongs.
@param[in] mtr the mini transaction context.
@return the undo record pointer where new data can be written.
@return nullptr when there is not enough space in undo page. */
static byte *trx_undo_report_blob_update(page_t *undo_page, dict_index_t *index,
byte *undo_ptr, const byte *field,
ulint flen, const upd_t *update,
upd_field_t *fld, mtr_t *mtr) {
DBUG_TRACE;
/* Access the LOB reference object. */
byte *field_ref = const_cast<byte *>(field) + flen - lob::ref_t::SIZE;
lob::ref_t ref(field_ref);
/* Check if enough space for flag and vector length. */
if (trx_undo_left(undo_page, undo_ptr) < 6) {
return nullptr;
}
/* Write one byte of flags. */
*undo_ptr = 0x00;
undo_ptr++;
if (fld == nullptr || update == nullptr) {
/* Write the size of the vector as 0. */
undo_ptr += mach_write_compressed(undo_ptr, 0);
return undo_ptr;
}
/* Find the Binary_diff object */
const Binary_diff_vector *bdiff_v =
update->get_binary_diff_by_field_no(fld->field_no);
if (bdiff_v == nullptr || !update->is_partially_updated(fld->field_no)) {
/* Write the size of the vector as 0. */
undo_ptr += mach_write_compressed(undo_ptr, 0);
return undo_ptr;
}
const ulint bytes_changed = upd_t::get_total_modified_bytes(*bdiff_v);
/* Whether the update to the LOB can be considered as a small change. */
const bool small_change =
(bytes_changed <= lob::ref_t::LOB_SMALL_CHANGE_THRESHOLD);
if (!small_change) {
/* This is not a small change. So write the size of the vector as
0 and bailout. */
undo_ptr += mach_write_compressed(undo_ptr, 0);
return undo_ptr;
}
const page_size_t page_size = dict_table_page_size(index->table);
if (page_size.is_compressed()) {
/* This is compressed LOB. Not yet supporting. */
undo_ptr += mach_write_compressed(undo_ptr, 0);
return undo_ptr;
}
trx_id_t last_trx_id;
undo_no_t last_undo_no;
ulint lob_version;
page_type_t f_page_type;
/* Obtain LOB info. */
lob::get_info(ref, index, lob_version, last_trx_id, last_undo_no, f_page_type,
mtr);
/* Only the page type FIL_PAGE_TYPE_LOB_FIRST is supported here. */
if (f_page_type != FIL_PAGE_TYPE_LOB_FIRST) {
undo_ptr += mach_write_compressed(undo_ptr, 0);
return undo_ptr;
}
/* Only for small changes to the BLOB, we do regular undo logging. */
size_t N = bdiff_v->size();
/* Write the size of the vector. */
undo_ptr += mach_write_compressed(undo_ptr, N);
if (N == 0) {
return undo_ptr;
}
/* Check if there is enough space for lob_version, last_trx_id
and last_undo_no. */
if (trx_undo_left(undo_page, undo_ptr) < 20) {
return nullptr;
}
/* Write the LOB first page number*/
undo_ptr += mach_write_compressed(undo_ptr, ref.page_no());
/* Write the lob version number */
undo_ptr += mach_write_compressed(undo_ptr, lob_version);
/* Write the last trx id */
undo_ptr += mach_write_compressed(undo_ptr, last_trx_id);
/* Write the last undo_no */
undo_ptr += mach_write_compressed(undo_ptr, last_undo_no);
for (size_t i = 0; i < N; ++i) {
const Binary_diff &bdiff = bdiff_v->at(i);
if (trx_undo_left(undo_page, undo_ptr) < 10) {
return nullptr;
}
/* Write the offset. */
undo_ptr += mach_write_compressed(undo_ptr, bdiff.offset());
/* Write the length. */
undo_ptr += mach_write_compressed(undo_ptr, bdiff.length());
if (trx_undo_left(undo_page, undo_ptr) < bdiff.length()) {
return nullptr;
}
/* Write the old data. */
ut_memcpy(undo_ptr, bdiff.old_data(fld->mysql_field), bdiff.length());
undo_ptr += bdiff.length();
lob::List_iem_t entries;
/* Find the affected LOB index entries. */
lob::get_affected_index_entries(ref, index, bdiff, entries, mtr);
ulint n_entry = entries.size();
ut_ad(n_entry == 1 || n_entry == 2);
/* Check if there is enough space for n_entry */
if (trx_undo_left(undo_page, undo_ptr) < 5) {
return nullptr;
}
/* Write the number of LOB index entries modified. */
undo_ptr += mach_write_compressed(undo_ptr, n_entry);
for (lob::List_iem_t::iterator iter = entries.begin();
iter != entries.end(); ++iter) {
if (trx_undo_left(undo_page, undo_ptr) < 10) {
return nullptr;
}
/* Write the modifier trx id of the LOB index entry. */
undo_ptr += mach_write_compressed(undo_ptr, iter->m_trx_id_modifier);
/* Write the modifier trx undo_no of the LOB index entry. */
undo_ptr += mach_write_compressed(undo_ptr, iter->m_undo_no_modifier);
}
}
return undo_ptr;
}
/**********************************************************************/ /**
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 ulint trx_undo_page_report_modify(
/*========================*/
page_t *undo_page, /*!< 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 ulint *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 */
{
DBUG_TRACE;
dict_table_t *table;
ulint first_free;
byte *ptr;
const byte *field;
ulint flen;
ulint col_no;
ulint type_cmpl;
byte *type_cmpl_ptr;
ulint i;
trx_id_t trx_id;
trx_undo_ptr_t *undo_ptr;
ibool ignore_prefix = FALSE;
byte ext_buf[REC_VERSION_56_MAX_INDEX_COL_LEN + BTR_EXTERN_FIELD_REF_SIZE];
bool first_v_col = true;
ut_a(index->is_clustered());
ut_ad(rec_offs_validate(rec, index, offsets));
ut_ad(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_TYPE) ==
TRX_UNDO_UPDATE);
table = index->table;
/* If table instance is temporary then select noredo rseg as changes
to undo logs don't need REDO logging given that they are not
restored on restart as corresponding object doesn't exist on restart.*/
undo_ptr =
index->table->is_temporary() ? &trx->rsegs.m_noredo : &trx->rsegs.m_redo;
first_free =
mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE);
ptr = undo_page + first_free;
ut_ad(first_free <= UNIV_PAGE_SIZE);
if (trx_undo_left(undo_page, ptr) < 50 + 8) {
/* 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;
/* Store first some general parameters to the undo log */
if (!update) {
ut_ad(!rec_get_deleted_flag(rec, dict_table_is_comp(table)));
type_cmpl = TRX_UNDO_DEL_MARK_REC;
} else if (rec_get_deleted_flag(rec, dict_table_is_comp(table))) {
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;
/* Introducing a change in undo log format. */
*type_cmpl_ptr |= TRX_UNDO_MODIFY_BLOB;
/* Introducing a new 1-byte flag. */
*ptr++ = 0x00;
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->get_sys_col_pos(DATA_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 (ignore_prefix) {
ignore_prefix = (trx_id != trx->id);
}
ptr += mach_u64_write_compressed(ptr, trx_id);
field = rec_get_nth_field(rec, offsets, index->get_sys_col_pos(DATA_ROLL_PTR),
&flen);
ut_ad(flen == DATA_ROLL_PTR_LEN);
ptr += mach_u64_write_compressed(ptr, trx_read_roll_ptr(field));
/*----------------------------------------*/
/* Lizard: store SCN, UBA, GCN */
/** Lizard: If updating a record whose last modification from the same
transaction, check if it has been cleanout. */
if (trx_id != trx->id) {
assert_row_lizard_has_cleanout(rec, index, offsets);
}
field = rec_get_nth_field(rec, offsets, index->get_sys_col_pos(DATA_SCN_ID),
&flen);
ut_ad(flen == DATA_SCN_ID_LEN);
ptr += mach_u64_write_compressed(ptr, lizard::trx_read_scn(field));
field = rec_get_nth_field(rec, offsets, index->get_sys_col_pos(DATA_UNDO_PTR),
&flen);
ut_ad(flen == DATA_UNDO_PTR_LEN);
ptr += mach_u64_write_compressed(ptr, lizard::trx_read_undo_ptr(field));
field = rec_get_nth_field(rec, offsets, index->get_sys_col_pos(DATA_GCN_ID),
&flen);
ut_ad(flen == DATA_GCN_ID_LEN);
ptr += mach_u64_write_compressed(ptr, lizard::trx_read_gcn(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++) {
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(!rec_offs_nth_default(offsets, i));
ut_ad(index->get_col(i)->ord_part);
if (trx_undo_left(undo_page, ptr) < 5) {
return 0;
}
ptr += mach_write_compressed(ptr, flen);
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr) < flen) {
return 0;
}
ut_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_page, 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) && 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--;
}
}
}
ptr += mach_write_compressed(ptr, n_updated);
for (i = 0; i < upd_get_n_fields(update); i++) {
upd_field_t *fld = upd_get_nth_field(update, i);
bool is_virtual = upd_fld_is_virtual_col(fld);
bool is_multi_val = upd_fld_is_multi_value_col(fld);
ulint max_v_log_len = 0;
ulint pos = fld->field_no;
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5) {
return 0;
}
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 */
pos += REC_MAX_N_FIELDS;
}
ptr += mach_write_compressed(ptr, pos);
/* Save the old value of field */
if (is_virtual) {
ut_ad(fld->field_no < table->n_v_def);
ptr = trx_undo_log_v_idx(undo_page, 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);
}
} else {
field = rec_get_nth_field_instant(rec, offsets, pos, index, &flen);
}
if (trx_undo_left(undo_page, ptr) < 15) {
return 0;
}
if (!is_virtual && rec_offs_nth_extern(offsets, pos)) {
ut_ad(!is_multi_val);
const dict_col_t *col = index->get_col(pos);
ulint prefix_len = dict_max_field_len_store_undo(table, col);
ut_ad(prefix_len + BTR_EXTERN_FIELD_REF_SIZE <= sizeof ext_buf);
ptr = trx_undo_page_report_modify_ext(
trx, index, ptr,
col->ord_part && !ignore_prefix &&
flen < REC_ANTELOPE_MAX_INDEX_COL_LEN
? ext_buf
: NULL,
prefix_len, dict_table_page_size(table), &field, &flen,
dict_table_is_sdi(table->id), SPATIAL_UNKNOWN);
/* Notify purge that it eventually has to
free the old externally stored field */
undo_ptr->update_undo->del_marks = TRUE;
*type_cmpl_ptr |= TRX_UNDO_UPD_EXTERN;
} else if (!is_multi_val) {
ptr += mach_write_compressed(ptr, flen);
}
if (is_multi_val) {
bool suc = trx_undo_store_multi_value(undo_page, fld->old_v_val, &ptr);
if (!suc) {
return 0;
}
} else if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr) < flen) {
return 0;
}
ut_memcpy(ptr, field, flen);
ptr += flen;
if (!is_virtual && rec_offs_nth_extern(offsets, pos)) {
ptr = trx_undo_report_blob_update(undo_page, index, ptr, field, flen,
update, fld, mtr);
if (ptr == nullptr) {
return 0;
}
}
}
/* 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_page, ptr) < 15) {
return 0;
}
if (is_multi_val) {
bool suc = trx_undo_store_multi_value(undo_page, &fld->new_val, &ptr);
if (!suc) {
return 0;
}
} else {
ptr += mach_write_compressed(ptr, flen);
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr) < flen) {
return 0;
}
ut_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;
undo_ptr->update_undo->del_marks = TRUE;
if (trx_undo_left(undo_page, 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 < table->get_n_cols(); col_no++) {
const dict_col_t *col = table->get_col(col_no);
if (col->ord_part) {
ulint pos;
spatial_status_t spatial_status;
spatial_status = SPATIAL_NONE;
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5 + 15) {
return 0;
}
pos = index->get_col_pos(col_no);
ptr += mach_write_compressed(ptr, pos);
/* Save the old value of field */
field = rec_get_nth_field_instant(rec, offsets, pos, index, &flen);
if (rec_offs_nth_extern(offsets, pos)) {
const dict_col_t *col = index->get_col(pos);
ulint prefix_len = dict_max_field_len_store_undo(table, col);
ut_a(prefix_len < sizeof ext_buf);
spatial_status = col->get_spatial_status();
/* 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(trx, index, mbr,
dict_table_page_size(table), field, &flen,
index->rtr_srs.get());
}
ptr = trx_undo_page_report_modify_ext(
trx, index, ptr,
flen < REC_ANTELOPE_MAX_INDEX_COL_LEN && !ignore_prefix ? ext_buf
: NULL,
prefix_len, dict_table_page_size(table), &field, &flen,
dict_table_is_sdi(table->id), spatial_status);
} else {
ptr += mach_write_compressed(ptr, flen);
}
if (flen != UNIV_SQL_NULL && spatial_status != SPATIAL_ONLY) {
if (trx_undo_left(undo_page, ptr) < flen) {
return 0;
}
ut_memcpy(ptr, field, flen);
ptr += flen;
}
if (spatial_status != SPATIAL_NONE) {
if (trx_undo_left(undo_page, ptr) < DATA_MBR_LEN) {
return 0;
}
for (int i = 0; i < SPDIMS * 2; i++) {
mach_double_write(ptr, mbr[i]);
ptr += sizeof(double);
}
}
}
}
for (col_no = 0; col_no < dict_table_get_n_v_cols(table); col_no++) {
dfield_t *vfield = NULL;
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_page, 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_page, table, col_no, ptr, first_v_col);
first_v_col = false;
if (!ptr) {
return 0;
}
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);
}
/* Prepare to write the field length and field data */
if (flen != UNIV_SQL_NULL) {
flen = ut_min(flen, max_v_log_len);
if (trx_undo_left(undo_page, ptr) < 5 + flen) {
return 0;
}
} else if (trx_undo_left(undo_page, ptr) < 5) {
return 0;
}
if (col->m_col.is_multi_value()) {
bool suc = trx_undo_store_multi_value(undo_page, vfield, &ptr);
if (!suc) {
return 0;
}
} else {
ptr += mach_write_compressed(ptr, flen);
if (flen != UNIV_SQL_NULL) {
ut_memcpy(ptr, field, flen);
ptr += flen;
}
}
}
}
mach_write_to_2(old_ptr, 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_page, ptr) < 2) {
return 0;
}
mach_write_to_2(ptr, first_free);
ptr += 2;
mach_write_to_2(undo_page + first_free, ptr - undo_page);
mach_write_to_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE,
ptr - undo_page);
/* Write to the REDO log about this change in the UNDO log */
trx_undof_page_add_undo_rec_log(undo_page, first_free, ptr - undo_page, mtr);
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 */
ulint *info_bits) /*!< out: info bits state */
{
/* Read the state of the info bits */
*info_bits = mach_read_from_1(ptr);
ptr += 1;
/* 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! */
const 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 */
ulint info_bits, /*!< in: info bits from this undo record */
trx_t *trx, /*!< in: transaction */
mem_heap_t *heap, /*!< in: memory heap from which the memory
needed is allocated */
upd_t **upd, /*!< out, own: update vector */
lob::undo_vers_t *lob_undo, /*!< out: LOB undo information. */
type_cmpl_t &type_cmpl, /*!< out: type compilation info */
txn_info_t txn_info) /*!< in: Lizard txn information */
{
DBUG_TRACE;
upd_field_t *upd_field;
upd_t *update;
ulint n_fields;
byte *buf;
ulint i;
bool first_v_col = true;
bool is_undo_log = true;
ulint n_skip_field = 0;
ut_a(index->is_clustered());
if (type != TRX_UNDO_DEL_MARK_REC) {
n_fields = mach_read_next_compressed(&ptr);
} else {
n_fields = 0;
}
update = upd_create(n_fields + 2 + DATA_N_LIZARD_COLS, 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));
trx_write_trx_id(buf, trx_id);
upd_field_set_field_no(upd_field, index->get_sys_col_pos(DATA_TRX_ID), index,
trx);
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->get_sys_col_pos(DATA_ROLL_PTR),
index, trx);
dfield_set_data(&(upd_field->new_val), buf, DATA_ROLL_PTR_LEN);
/** Lizard: Fill the lizard fields into update vector */
lizard::trx_undo_update_rec_by_lizard_fields(trx, index, update, n_fields + 2,
txn_info, heap);
/* Store then the updated ordinary columns to the update vector */
for (i = 0; i < n_fields; i++) {
const byte *field;
ulint len;
ulint field_no;
ulint orig_len;
bool is_virtual;
dict_v_col_t *vcol = nullptr;
field_no = mach_read_next_compressed(&ptr);
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;
} else if (field_no >= dict_index_get_n_fields(index)) {
ib::error(ER_IB_MSG_1184)
<< "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 << ", ptr " << ptr;
ut_ad(0);
*upd = NULL;
return NULL;
}
upd_field = upd_get_nth_field(update, i);
if (is_virtual) {
/* This column could be dropped or no longer indexed */
if (field_no == ULINT_UNDEFINED) {
/* Mark this is no longer needed */
upd_field->field_no = REC_MAX_N_FIELDS;
if (trx_undo_rec_is_multi_value(ptr)) {
ptr = trx_undo_rec_get_multi_value(ptr, nullptr, heap);
ut_ad(trx_undo_rec_is_multi_value(ptr));
ptr = trx_undo_rec_get_multi_value(ptr, nullptr, heap);
} else {
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;
} else {
vcol = dict_table_get_nth_v_col(index->table, field_no);
}
upd_field_set_v_field_no(upd_field, field_no, index);
} else {
upd_field_set_field_no(upd_field, field_no, index, trx);
}
if (vcol != nullptr && vcol->m_col.is_multi_value()) {
ptr = trx_undo_rec_get_multi_value(ptr, &upd_field->new_val, heap);
} else {
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
upd_field->orig_len = 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);
if (type_cmpl.is_lob_undo() && type_cmpl.is_lob_updated()) {
/* Read the partial update on LOB */
ptr = trx_undo_read_blob_update(ptr, upd_field, lob_undo);
}
}
}
if (is_virtual) {
upd_field->old_v_val = static_cast<dfield_t *>(
mem_heap_zalloc(heap, sizeof *upd_field->old_v_val));
if (vcol != nullptr && vcol->m_col.is_multi_value()) {
ptr = trx_undo_rec_get_multi_value(ptr, upd_field->old_v_val, heap);
} else {
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);
}
}
}
}
/* In rare scenario, we could have skipped virtual column (as they
are dropped. We will regenerate a update vector and skip them */
if (n_skip_field > 0) {
ulint n = 0;
ut_ad(n_skip_field <= n_fields);
upd_t *new_update = upd_create(n_fields + 2 - n_skip_field, heap);
for (i = 0; i < n_fields + 2; i++) {
upd_field = upd_get_nth_field(update, i);
if (upd_field->field_no == REC_MAX_N_FIELDS) {
continue;
}
upd_field_t *new_upd_field = upd_get_nth_field(new_update, n);
*new_upd_field = *upd_field;
n++;
}
ut_ad(n == n_fields + 2 - n_skip_field);
*upd = new_update;
} else {
*upd = update;
}
return const_cast<byte *>(ptr);
}
/** Builds a partial row from an update undo log record, for purge.
It contains the columns which occur as ordering in any index of the table.
Any missing columns are indicated by col->mtype == DATA_MISSING.
@return pointer to remaining part of undo record */
byte *trx_undo_rec_get_partial_row(
const byte *ptr, /*!< in: remaining part in update undo log
record of a suitable type, at the start of
the stored index columns;
NOTE that this copy of the undo log record must
be preserved as long as the partial row is
used, as we do NOT copy the data in the
record! */
dict_index_t *index, /*!< in: clustered index */
dtuple_t **row, /*!< out, own: partial row */
ibool ignore_prefix, /*!< in: flag to indicate if we
expect blob prefixes in undo. Used
only in the assertion. */
mem_heap_t *heap) /*!< in: memory heap from which the memory
needed is allocated */
{
const byte *end_ptr;
bool first_v_col = true;
bool is_undo_log = true;
ut_ad(index);
ut_ad(ptr);
ut_ad(row);
ut_ad(heap);
ut_ad(index->is_clustered());
*row = dtuple_create_with_vcol(heap, index->table->get_n_cols(),
dict_table_get_n_v_cols(index->table));
/* Mark all columns in the row uninitialized, so that
we can distinguish missing fields from fields that are SQL NULL. */
for (ulint i = 0; i < index->table->get_n_cols(); i++) {
dfield_get_type(dtuple_get_nth_field(*row, i))->mtype = DATA_MISSING;
/* In case a multi-value field checking read uninitialized value */
dfield_get_type(dtuple_get_nth_field(*row, i))->prtype = 0;
}
dtuple_init_v_fld(*row);
end_ptr = ptr + mach_read_from_2(ptr);
ptr += 2;
while (ptr != end_ptr) {
dfield_t *dfield = nullptr;
const byte *field;
ulint field_no = ULINT_UNDEFINED;
const dict_col_t *col = nullptr;
ulint col_no;
ulint len;
ulint orig_len;
bool is_virtual;
dict_v_col_t *vcol = nullptr;
field_no = mach_read_next_compressed(&ptr);
is_virtual = (field_no >= REC_MAX_N_FIELDS);
if (is_virtual) {
ptr = trx_undo_read_v_idx(index->table, ptr, first_v_col, &is_undo_log,
&field_no);
first_v_col = false;
if (field_no != ULINT_UNDEFINED) {
vcol = dict_table_get_nth_v_col(index->table, field_no);
col = &vcol->m_col;
col_no = dict_col_get_no(col);
dfield = dtuple_get_nth_v_field(*row, vcol->v_pos);
vcol->m_col.copy_type(dfield_get_type(dfield));
}
}
if ((vcol != nullptr && vcol->m_col.is_multi_value()) ||
trx_undo_rec_is_multi_value(ptr)) {
ut_ad(is_virtual);
ut_ad(vcol != nullptr || field_no == ULINT_UNDEFINED);
ut_ad(dfield != nullptr || field_no == ULINT_UNDEFINED);
ptr = trx_undo_rec_get_multi_value(ptr, dfield, heap);
continue;
} else {
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
}
/* This column could be dropped or no longer indexed */
if (field_no == ULINT_UNDEFINED) {
ut_ad(is_virtual);
continue;
}
if (!is_virtual) {
col = index->get_col(field_no);
col_no = dict_col_get_no(col);
dfield = dtuple_get_nth_field(*row, col_no);
index->table->get_col(col_no)->copy_type(dfield_get_type(dfield));
}
dfield_set_data(dfield, field, len);
if (len != UNIV_SQL_NULL && len >= UNIV_EXTERN_STORAGE_FIELD) {
spatial_status_t spatial_status;
/* Decode spatial status. */
spatial_status = static_cast<spatial_status_t>(
(len & SPATIAL_STATUS_MASK) >> SPATIAL_STATUS_SHIFT);
len &= ~SPATIAL_STATUS_MASK;
/* Keep compatible with 5.7.9 format. */
if (spatial_status == SPATIAL_UNKNOWN) {
spatial_status = col->get_spatial_status();
}
switch (spatial_status) {
case SPATIAL_ONLY:
ut_ad(len - UNIV_EXTERN_STORAGE_FIELD == DATA_MBR_LEN);
dfield_set_len(dfield, len - UNIV_EXTERN_STORAGE_FIELD);
break;
case SPATIAL_MIXED:
dfield_set_len(dfield,
len - UNIV_EXTERN_STORAGE_FIELD - DATA_MBR_LEN);
break;
case SPATIAL_NONE:
dfield_set_len(dfield, len - UNIV_EXTERN_STORAGE_FIELD);
break;
case SPATIAL_UNKNOWN:
ut_ad(0);
break;
}
dfield_set_ext(dfield);
dfield_set_spatial_status(dfield, spatial_status);
/* If the prefix of this column is indexed,
ensure that enough prefix is stored in the
undo log record. */
if (!ignore_prefix && col->ord_part && spatial_status != SPATIAL_ONLY) {
ut_a(dfield_get_len(dfield) >= BTR_EXTERN_FIELD_REF_SIZE);
ut_a(dict_table_has_atomic_blobs(index->table) ||
dfield_get_len(dfield) >=
REC_ANTELOPE_MAX_INDEX_COL_LEN + BTR_EXTERN_FIELD_REF_SIZE);
}
}
}
return (const_cast<byte *>(ptr));
}
#endif /* !UNIV_HOTBACKUP */
/** Erases the unused undo log page end.
@return true if the page contained something, false if it was empty */
static ibool trx_undo_erase_page_end(
page_t *undo_page, /*!< in/out: undo page whose end to erase */
mtr_t *mtr) /*!< in/out: mini-transaction */
{
ulint first_free;
first_free =
mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE);
memset(undo_page + first_free, 0xff,
(UNIV_PAGE_SIZE - FIL_PAGE_DATA_END) - first_free);
mlog_write_initial_log_record(undo_page, MLOG_UNDO_ERASE_END, mtr);
return (first_free != TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE);
}
/** Parses a redo log record of erasing of an undo page end.
@return end of log record or NULL */
byte *trx_undo_parse_erase_page_end(
byte *ptr, /*!< in: buffer */
byte *end_ptr MY_ATTRIBUTE((unused)), /*!< in: buffer end */
page_t *page, /*!< in: page or NULL */
mtr_t *mtr) /*!< in: mtr or NULL */
{
ut_ad(ptr != NULL);
ut_ad(end_ptr != NULL);
if (page == NULL) {
return (ptr);
}
trx_undo_erase_page_end(page, mtr);
return (ptr);
}
#ifndef UNIV_HOTBACKUP
/** 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(
ulint flags, /*!< in: if BTR_NO_UNDO_LOG_FLAG bit is
set, does nothing */
ulint op_type, /*!< in: TRX_UNDO_INSERT_OP or
TRX_UNDO_MODIFY_OP */
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, 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: in case of an update or delete
marking, the record in the clustered
index, otherwise NULL */
const ulint *offsets, /*!< in: rec_get_offsets(rec) */
roll_ptr_t *roll_ptr) /*!< out: rollback pointer to the
inserted undo log record,
0 if BTR_NO_UNDO_LOG
flag was specified */
{
trx_t *trx;
trx_undo_t *undo;
page_no_t page_no;
buf_block_t *undo_block;
trx_undo_ptr_t *undo_ptr;
mtr_t mtr;
dberr_t err = DB_SUCCESS;
#ifdef UNIV_DEBUG
int loop_count = 0;
#endif /* UNIV_DEBUG */
ut_a(index->is_clustered());
ut_ad(!rec || rec_offs_validate(rec, index, offsets));
if (flags & BTR_NO_UNDO_LOG_FLAG) {
*roll_ptr = 0;
return (DB_SUCCESS);
}
ut_ad(thr);
ut_ad(!srv_read_only_mode);
ut_ad((op_type != TRX_UNDO_INSERT_OP) || (clust_entry && !update && !rec));
trx = thr_get_trx(thr);
bool is_temp_table = index->table->is_temporary();
/* Temporary tables do not go into INFORMATION_SCHEMA.TABLES,
so do not bother adding it to the list of modified tables by
the transaction - this list is only used for maintaining
INFORMATION_SCHEMA.TABLES.UPDATE_TIME. */
if (!is_temp_table) {
trx->mod_tables.insert(index->table);
}
/* If trx is read-only then only temp-tables can be written. */
ut_ad(!trx->read_only || is_temp_table);
/* If this is a temp-table then we assign temporary rseg. */
if (is_temp_table && trx->rsegs.m_noredo.rseg == nullptr) {
trx_assign_rseg_temp(trx);
}
mtr_start(&mtr);
if (is_temp_table) {
/* If object is temporary, disable REDO logging that
is done to track changes done to UNDO logs. This is
feasible given that temporary tables and temporary
undo logs are not restored on restart. */
undo_ptr = &trx->rsegs.m_noredo;
mtr.set_log_mode(MTR_LOG_NO_REDO);
} else {
undo_ptr = &trx->rsegs.m_redo;
}
mutex_enter(&trx->undo_mutex);
#ifdef UNIV_DEBUG
if (srv_inject_too_many_concurrent_trxs) {
err = DB_TOO_MANY_CONCURRENT_TRXS;
goto err_exit;
}
#endif /* UNIV_DEBUG */
switch (op_type) {
case TRX_UNDO_INSERT_OP:
undo = undo_ptr->insert_undo;
if (undo == NULL) {
err = trx_undo_assign_undo(trx, undo_ptr, TRX_UNDO_INSERT);
undo = undo_ptr->insert_undo;
if (undo == NULL) {
/* Did not succeed */
ut_ad(err != DB_SUCCESS);
goto err_exit;
}
}
ut_ad(err == DB_SUCCESS);
break;
default:
ut_ad(op_type == TRX_UNDO_MODIFY_OP);
undo = undo_ptr->update_undo;
if (undo == NULL) {
err = trx_undo_assign_undo(trx, undo_ptr, TRX_UNDO_UPDATE);
undo = undo_ptr->update_undo;
if (undo == NULL) {
/* Did not succeed */
ut_ad(err != DB_SUCCESS);
goto err_exit;
}
}
ut_ad(err == DB_SUCCESS);
break;
}
page_no = undo->last_page_no;
undo_block = buf_page_get_gen(
page_id_t(undo->space, page_no), undo->page_size, RW_X_LATCH,
buf_pool_is_obsolete(undo->withdraw_clock) ? NULL : undo->guess_block,
Page_fetch::NORMAL, __FILE__, __LINE__, &mtr);
buf_block_dbg_add_level(undo_block, SYNC_TRX_UNDO_PAGE);
do {
page_t *undo_page;
ulint offset;
undo_page = buf_block_get_frame(undo_block);
ut_ad(page_no == undo_block->page.id.page_no());
switch (op_type) {
case TRX_UNDO_INSERT_OP:
offset = trx_undo_page_report_insert(undo_page, trx, index, clust_entry,
&mtr);
break;
default:
ut_ad(op_type == TRX_UNDO_MODIFY_OP);
offset =
trx_undo_page_report_modify(undo_page, trx, index, rec, offsets,
update, cmpl_info, clust_entry, &mtr);
}
if (UNIV_UNLIKELY(offset == 0)) {
/* The record did not fit on the page. We erase the
end segment of the undo log page and write a log
record of it: this is to ensure that in the debug
version the replicate page constructed using the log
records stays identical to the original page */
if (!trx_undo_erase_page_end(undo_page, &mtr)) {
/* 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 and SYNC_FSP_PAGE. */
mtr_commit(&mtr);
mtr_start(&mtr);
if (index->table->is_temporary()) {
mtr.set_log_mode(MTR_LOG_NO_REDO);
}
mutex_enter(&undo_ptr->rseg->mutex);
trx_undo_free_last_page(trx, undo, &mtr);
mutex_exit(&undo_ptr->rseg->mutex);
err = DB_UNDO_RECORD_TOO_BIG;
goto err_exit;
}
mtr_commit(&mtr);
} else {
/* Success */
undo->withdraw_clock = buf_withdraw_clock;
mtr_commit(&mtr);
undo->empty = FALSE;
undo->top_page_no = page_no;
undo->top_offset = offset;
undo->top_undo_no = trx->undo_no;
undo->guess_block = undo_block;
trx->undo_no++;
trx->undo_rseg_space = undo_ptr->rseg->space_id;
mutex_exit(&trx->undo_mutex);
*roll_ptr =
trx_undo_build_roll_ptr(op_type == TRX_UNDO_INSERT_OP,
undo_ptr->rseg->space_id, page_no, offset);
return (DB_SUCCESS);
}
ut_ad(page_no == undo->last_page_no);
/* We have to extend the undo log by one page */
ut_ad(++loop_count < 2);
mtr_start(&mtr);
if (index->table->is_temporary()) {
mtr.set_log_mode(MTR_LOG_NO_REDO);
}
/* When we add a page to 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. */
mutex_enter(&undo_ptr->rseg->mutex);
undo_block = trx_undo_add_page(trx, undo, undo_ptr, &mtr);
mutex_exit(&undo_ptr->rseg->mutex);
page_no = undo->last_page_no;
DBUG_EXECUTE_IF("ib_err_ins_undo_page_add_failure", undo_block = NULL;);
} while (undo_block != NULL);
ib_errf(
trx->mysql_thd, IB_LOG_LEVEL_ERROR, 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->space == TRX_SYS_SPACE)
? "system"
: ((fsp_is_system_temporary(undo->space)) ? "temporary" : "undo")));
/* Did not succeed: out of space */
err = DB_OUT_OF_FILE_SPACE;
err_exit:
mutex_exit(&trx->undo_mutex);
mtr_commit(&mtr);
return (err);
}
/*============== BUILDING PREVIOUS VERSION OF A RECORD ===============*/
/** Copies an undo record to heap. This function can be called if we know that
the undo log record exists.
@return own: copy of the record */
static MY_ATTRIBUTE((warn_unused_result))
trx_undo_rec_t *trx_undo_get_undo_rec_low(
roll_ptr_t roll_ptr, /*!< in: roll pointer to record */
mem_heap_t *heap, /*!< in: memory heap where copied */
bool is_temp) /*!< in: true if temp undo rec. */
{
trx_undo_rec_t *undo_rec;
ulint rseg_id;
space_id_t space_id;
page_no_t page_no;
ulint offset;
const page_t *undo_page;
ibool is_insert;
mtr_t mtr;
trx_undo_decode_roll_ptr(roll_ptr, &is_insert, &rseg_id, &page_no, &offset);
space_id = trx_rseg_id_to_space_id(rseg_id, is_temp);
bool found;
const page_size_t &page_size = fil_space_get_page_size(space_id, &found);
ut_ad(found);
mtr_start(&mtr);
undo_page = trx_undo_page_get_s_latched(page_id_t(space_id, page_no),
page_size, &mtr);
undo_rec = trx_undo_rec_copy(undo_page + offset, heap);
mtr_commit(&mtr);
return (undo_rec);
}
/** Copies an undo record to heap.
@param[in] roll_ptr roll pointer to record
@param[in/out] txn_rec txn_info of record, Liard;
trx_id of the trx that generated
the roll pointer: it points to an
undo log of this transaction
@param[in] heap memory heap where copied
@param[in] is_temp true if temporary, no-redo rseg.
@param[in] name table name
@param[out] undo_rec own: copy of the record
@param[in] is_as_of If it's a as-of query (lizard)
@param[in] txn_mtr txn mtr (lizard)
@retval true if the undo log has been
truncated and we cannot fetch the old version
@retval false if the undo log record is available
NOTE: the caller must have latches on the clustered index page. */
static MY_ATTRIBUTE((warn_unused_result)) bool trx_undo_get_undo_rec(
roll_ptr_t roll_ptr, txn_rec_t *txn_rec, mem_heap_t *heap, bool is_temp,
const table_name_t &name, trx_undo_rec_t **undo_rec,
bool is_as_of, mtr_t *txn_mtr) {
bool missing_history = false;
txn_lookup_t txn_lookup;
rw_lock_s_lock(&purge_sys->latch);
if (is_as_of) {
/** precheck, if the record has been cleanout, and the TXN has been purged,
no need to hold TXN page latch and undo page latch */
if (lizard::precheck_if_txn_is_purged(txn_rec)) {
/** Must be cleanout, so no need to lookup again */
ut_ad(!lizard::lizard_undo_ptr_is_active(txn_rec->undo_ptr));
missing_history = true;
} else {
/** precheck fail */
lizard::txn_rec_lock_state_by_lookup(txn_rec, &txn_lookup, txn_mtr);
missing_history = !lizard::txn_lookup_rollptr_is_valid(&txn_lookup);
}
DBUG_EXECUTE_IF("simulate_prev_image_purged_during_query",
missing_history = true;);
} else {
lizard::txn_rec_real_state_by_misc(txn_rec);
missing_history = purge_sys->vision.modifications_visible(txn_rec, name);
}
if (!missing_history) {
*undo_rec = trx_undo_get_undo_rec_low(roll_ptr, heap, is_temp);
}
rw_lock_s_unlock(&purge_sys->latch);
return (missing_history);
}
#ifdef UNIV_DEBUG
#define ATTRIB_USED_ONLY_IN_DEBUG
#else /* UNIV_DEBUG */
#define ATTRIB_USED_ONLY_IN_DEBUG MY_ATTRIBUTE((unused))
#endif /* UNIV_DEBUG */
bool trx_undo_prev_version_build(
const rec_t *index_rec ATTRIB_USED_ONLY_IN_DEBUG,
mtr_t *index_mtr ATTRIB_USED_ONLY_IN_DEBUG, const rec_t *rec,
const dict_index_t *const index, ulint *offsets, mem_heap_t *heap,
rec_t **old_vers, mem_heap_t *v_heap, const dtuple_t **vrow, ulint v_status,
lob::undo_vers_t *lob_undo,
const lizard::Vision *vision) {
DBUG_TRACE;
trx_undo_rec_t *undo_rec = NULL;
dtuple_t *entry;
trx_id_t rec_trx_id;
ulint type;
undo_no_t undo_no;
table_id_t table_id;
trx_id_t trx_id;
roll_ptr_t roll_ptr;
upd_t *update = nullptr;
byte *ptr;
ulint info_bits;
ulint cmpl_info;
bool dummy_extern;
byte *buf;
txn_info_t txn_info;
txn_rec_t txn_rec;
mtr_t txn_mtr;
bool is_as_of = vision ? vision->is_asof() : false;
bool is_as_of_gcn = vision ? vision->is_asof_gcn() : false;
ut_ad(!rw_lock_own(&purge_sys->latch, RW_LOCK_S));
ut_ad(mtr_memo_contains_page(index_mtr, index_rec, MTR_MEMO_PAGE_S_FIX) ||
mtr_memo_contains_page(index_mtr, index_rec, MTR_MEMO_PAGE_X_FIX));
ut_ad(rec_offs_validate(rec, index, offsets));
ut_a(index->is_clustered());
roll_ptr = row_get_rec_roll_ptr(rec, index, offsets);
*old_vers = NULL;
if (trx_undo_roll_ptr_is_insert(roll_ptr)) {
/* The record rec is the first inserted version */
return true;
}
rec_trx_id = row_get_rec_trx_id(rec, index, offsets);
/** Lizard begin */
txn_rec.scn = lizard::row_get_rec_scn_id(rec, index, offsets);
txn_rec.undo_ptr = lizard::row_get_rec_undo_ptr(rec, index, offsets);
txn_rec.gcn = lizard::row_get_rec_gcn(rec, index, offsets);
assert_undo_ptr_allocated(txn_rec.undo_ptr);
txn_rec.trx_id = rec_trx_id;
/** Lizard end */
/* REDO rollback segments are used only for non-temporary objects.
For temporary objects NON-REDO rollback segments are used. */
bool is_temp = index->table->is_temporary();
ut_ad(!index->table->skip_alter_undo);
mtr_start(&txn_mtr);
if (trx_undo_get_undo_rec(roll_ptr, &txn_rec, heap, is_temp,
index->table->name, &undo_rec,
is_as_of, &txn_mtr)) {
if (v_status & TRX_UNDO_PREV_IN_PURGE) {
/* We are fetching the record being purged */
undo_rec = trx_undo_get_undo_rec_low(roll_ptr, heap, is_temp);
} else {
mtr_commit(&txn_mtr);
/* The undo record may already have been purged,
during purge or semi-consistent read. */
return false;
}
}
mtr_commit(&txn_mtr);
type_cmpl_t type_cmpl;
ptr = trx_undo_rec_get_pars(undo_rec, &type, &cmpl_info, &dummy_extern,
&undo_no, &table_id, type_cmpl);
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 true;
}
ptr = trx_undo_update_rec_get_sys_cols(ptr, &trx_id, &roll_ptr, &info_bits);
/** Lizard: Retrieve txn info from undo log record */
ptr = lizard::trx_undo_update_rec_get_lizard_cols(ptr, &txn_info);
/* (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);
ptr = trx_undo_update_rec_get_update(ptr, index, type, trx_id, roll_ptr,
info_bits, NULL, heap, &update, lob_undo,
type_cmpl, txn_info);
ut_a(ptr);
if (row_upd_changes_field_size_or_external(index, offsets, update)) {
ulint n_ext;
/* 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. */
/* the row_upd_changes_disowned_external(update) call could be
omitted, but the synchronization on purge_sys->latch is likely
more expensive. */
if ((update->info_bits & REC_INFO_DELETED_FLAG) &&
row_upd_changes_disowned_external(update)) {
bool missing_extern;
rw_lock_s_lock(&purge_sys->latch);
txn_rec_t undo_txn_rec = {
trx_id,
txn_info.scn,
txn_info.undo_ptr,
txn_info.gcn,
};
lizard::txn_rec_real_state_by_misc(&undo_txn_rec);
missing_extern = purge_sys->vision.modifications_visible(
&undo_txn_rec, index->table->name);
rw_lock_s_unlock(&purge_sys->latch);
if (missing_extern) {
/* treat as a fresh insert, not to
cause assertion error at the caller. */
return true;
}
}
/* 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: */
entry = row_rec_to_index_entry(rec, index, offsets, &n_ext, heap);
n_ext += lob::btr_push_update_extern_fields(entry, update, heap);
/* The page containing the clustered index record
corresponding to entry is latched in mtr. Thus the
following call is safe. */
row_upd_index_replace_new_col_vals(entry, index, update, heap);
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, offsets);
row_upd_rec_in_place(*old_vers, index, offsets, update, NULL);
}
/* 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, NULL,
NULL);
}
#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
ut_a(!rec_offs_any_null_extern(
*old_vers,
rec_get_offsets(*old_vers, index, NULL, ULINT_UNDEFINED, &heap)));
#endif // defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
/* If vrow is not NULL it means that the caller is interested in the values of
the virtual columns for this version.
If the UPD_NODE_NO_ORD_CHANGE flag is set on cmpl_info, it means that the
change which created this entry in undo log did not affect any column of any
secondary index (in particular: virtual), and thus the values of virtual
columns were not recorded in undo. In such case the caller may assume that the
values of (virtual) columns present in secondary index are exactly the same as
they are in the next (more recent) version.
If on the other hand the UPD_NODE_NO_ORD_CHANGE flag is not set, then we will
make sure that *vrow points to a properly allocated memory and contains the
values of virtual columns for this version recovered from undo log.
This implies that if the caller has provided a non-NULL vrow, and the *vrow is
still NULL after the call, (and old_vers is not NULL) it must be because the
UPD_NODE_NO_ORD_CHANGE flag was set for this version.
This last statement is an important assumption made by the
row_vers_impl_x_locked_low() function. */
if (vrow && !(cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
if (!(*vrow)) {
*vrow = dtuple_create_with_vcol(v_heap ? v_heap : heap,
index->table->get_n_cols(),
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, false, nullptr,
(v_heap != nullptr ? v_heap : heap));
}
if (update != nullptr) {
update->reset();
}
return true;
}
/** Read virtual column value from undo log
@param[in] table the table
@param[in] ptr undo log pointer
@param[in,out] row the row struct to fill
@param[in] in_purge called by purge thread
@param[in] online true if this is from online DDL log
@param[in] col_map online rebuild column map
@param[in,out] heap memory heap to keep value when necessary */
void trx_undo_read_v_cols(const dict_table_t *table, const byte *ptr,
const dtuple_t *row, bool in_purge, bool online,
const ulint *col_map, mem_heap_t *heap) {
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;
dfield_t multi_value_field;
const byte *field;
ulint field_no;
ulint len = 0;
ulint orig_len = 0;
bool is_virtual;
dict_v_col_t *vcol = nullptr;
ulint col_no;
field_no = mach_read_next_compressed(const_cast<const byte **>(&ptr));
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;
}
if (!is_virtual || field_no == ULINT_UNDEFINED) {
/* The virtual column is no longer indexed or does not exist.
"continue" needs to put after ptr gets advanced */
if (trx_undo_rec_is_multi_value(ptr)) {
ptr = trx_undo_rec_get_multi_value(ptr, nullptr, heap);
} else {
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
}
continue;
}
vcol = dict_table_get_nth_v_col(table, field_no);
if (!col_map) {
col_no = vcol->v_pos;
} else {
col_no = col_map[vcol->v_pos];
}
if (col_no == ULINT_UNDEFINED) {
if (trx_undo_rec_is_multi_value(ptr)) {
ptr = trx_undo_rec_get_multi_value(ptr, nullptr, heap);
} else {
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
}
continue;
}
dfield = dtuple_get_nth_v_field(row, col_no);
if (trx_undo_rec_is_multi_value(ptr)) {
ut_ad(vcol->m_col.is_multi_value());
ptr = trx_undo_rec_get_multi_value(ptr, &multi_value_field, heap);
} else {
ut_ad(!vcol->m_col.is_multi_value());
ptr = trx_undo_rec_get_col_val(ptr, &field, &len, &orig_len);
}
if (!in_purge || dfield_get_type(dfield)->mtype == DATA_MISSING) {
vcol->m_col.copy_type(dfield_get_type(dfield));
if (online && !vcol->m_col.is_multi_value()) {
dfield->adjust_v_data_mysql(vcol, dict_table_is_comp(table), field, len,
heap);
} else if (!vcol->m_col.is_multi_value()) {
dfield_set_data(dfield, field, len);
} else {
dfield_copy_data(dfield, &multi_value_field);
}
}
}
ut_ad(ptr == end_ptr);
}
#endif /* !UNIV_HOTBACKUP */
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