void
row_upd_index_entry_sys_field(
/*==========================*/
dtuple_t* entry, /* in: index entry, where the memory buffers
for sys fields are already allocated:
the function just copies the new values to
them */
dict_index_t* index, /* in: clustered index */
ulint type, /* in: DATA_TRX_ID or DATA_ROLL_PTR */
dulint val) /* in: value to write */
{
dfield_t* dfield;
byte* field;
ulint pos;
ut_ad(index->type & DICT_CLUSTERED);
pos = dict_index_get_sys_col_pos(index, type);
dfield = dtuple_get_nth_field(entry, pos);
field = dfield_get_data(dfield);
if (type == DATA_TRX_ID) {
trx_write_trx_id(field, val);
} else {
ut_ad(type == DATA_ROLL_PTR);
trx_write_roll_ptr(field, val);
}
}
void
row_set_rec_sys_field(
/*==================*/
/* out: value of the field */
ulint type, /* in: DATA_TRX_ID or DATA_ROLL_PTR */
rec_t* rec, /* in: record */
dict_index_t* index, /* in: clustered index */
dulint val) /* in: value to set */
{
ulint pos;
byte* field;
ulint len;
ut_ad(index->type & DICT_CLUSTERED);
pos = dict_index_get_sys_col_pos(index, type);
field = rec_get_nth_field(rec, pos, &len);
if (type == DATA_TRX_ID) {
trx_write_trx_id(field, val);
} else {
ut_ad(type == DATA_ROLL_PTR);
trx_write_roll_ptr(field, val);
}
}
byte*
row_upd_write_sys_vals_to_log(
/*==========================*/
/* out: new pointer to mlog */
dict_index_t* index, /* in: clustered index */
trx_t* trx, /* in: transaction */
dulint roll_ptr,/* in: roll ptr of the undo log record */
byte* log_ptr,/* pointer to a buffer of size > 20 opened
in mlog */
mtr_t* mtr) /* in: mtr */
{
ut_ad(index->type & DICT_CLUSTERED);
ut_ad(mtr);
log_ptr += mach_write_compressed(log_ptr,
dict_index_get_sys_col_pos(index, DATA_TRX_ID));
trx_write_roll_ptr(log_ptr, roll_ptr);
log_ptr += DATA_ROLL_PTR_LEN;
log_ptr += mach_dulint_write_compressed(log_ptr, trx->id);
return(log_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 */
UNIV_INTERN
byte*
trx_undo_update_rec_get_update(
/*===========================*/
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 */
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 */
{
upd_field_t* upd_field;
upd_t* update;
ulint n_fields;
byte* buf;
ulint i;
ut_a(dict_index_is_clust(index));
if (type != TRX_UNDO_DEL_MARK_REC) {
ptr = trx_undo_update_rec_get_n_upd_fields(ptr, &n_fields);
} else {
n_fields = 0;
}
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 = mem_heap_alloc(heap, DATA_TRX_ID_LEN);
trx_write_trx_id(buf, trx_id);
upd_field_set_field_no(upd_field,
dict_index_get_sys_col_pos(index, 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 = mem_heap_alloc(heap, DATA_ROLL_PTR_LEN);
trx_write_roll_ptr(buf, roll_ptr);
upd_field_set_field_no(
upd_field, dict_index_get_sys_col_pos(index, DATA_ROLL_PTR),
index, trx);
dfield_set_data(&(upd_field->new_val), buf, DATA_ROLL_PTR_LEN);
/* Store then the updated ordinary columns to the update vector */
for (i = 0; i < n_fields; i++) {
byte* field;
ulint len;
ulint field_no;
ulint orig_len;
ptr = trx_undo_update_rec_get_field_no(ptr, &field_no);
if (field_no >= dict_index_get_n_fields(index)) {
fprintf(stderr,
"InnoDB: Error: trying to access"
" update undo rec field %lu in ",
(ulong) field_no);
dict_index_name_print(stderr, trx, index);
fprintf(stderr, "\n"
"InnoDB: but index has only %lu fields\n"
"InnoDB: Submit a detailed bug report"
" to http://bugs.mysql.com\n"
"InnoDB: Run also CHECK TABLE ",
(ulong) dict_index_get_n_fields(index));
ut_print_name(stderr, trx, TRUE, index->table_name);
fprintf(stderr, "\n"
"InnoDB: n_fields = %lu, i = %lu, ptr %p\n",
(ulong) n_fields, (ulong) i, ptr);
*upd = NULL;
return(NULL);
}
upd_field = upd_get_nth_field(update, i);
upd_field_set_field_no(upd_field, field_no, index, trx);
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);
}
}
*upd = update;
return(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 */
mtr_t* mtr) /*!< in: mtr */
{
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;
ibool ignore_prefix = FALSE;
byte ext_buf[REC_MAX_INDEX_COL_LEN
+ BTR_EXTERN_FIELD_REF_SIZE];
ut_a(dict_index_is_clust(index));
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;
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) {
/* 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) {
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;
ptr += mach_dulint_write_much_compressed(ptr, trx->undo_no);
ptr += mach_dulint_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,
dict_index_get_sys_col_pos(
index, 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 = ut_dulint_cmp(trx_id, trx->id) != 0;
}
ptr += mach_dulint_write_compressed(ptr, trx_id);
field = rec_get_nth_field(rec, offsets,
dict_index_get_sys_col_pos(
index, DATA_ROLL_PTR), &flen);
ut_ad(flen == DATA_ROLL_PTR_LEN);
ptr += mach_dulint_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++) {
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_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);
}
ptr += mach_write_compressed(ptr, upd_get_n_fields(update));
for (i = 0; i < upd_get_n_fields(update); i++) {
ulint pos = upd_get_nth_field(update, i)->field_no;
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
ptr += mach_write_compressed(ptr, pos);
/* Save the old value of field */
field = rec_get_nth_field(rec, offsets, pos, &flen);
if (trx_undo_left(undo_page, ptr) < 15) {
return(0);
}
if (rec_offs_nth_extern(offsets, pos)) {
ptr = trx_undo_page_report_modify_ext(
ptr,
dict_index_get_nth_col(index, pos)
->ord_part
&& !ignore_prefix
&& flen < REC_MAX_INDEX_COL_LEN
? ext_buf : NULL,
dict_table_zip_size(table),
&field, &flen);
/* Notify purge that it eventually has to
free the old externally stored field */
trx->update_undo->del_marks = TRUE;
*type_cmpl_ptr |= TRX_UNDO_UPD_EXTERN;
} 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;
}
}
}
/*----------------------------------------*/
/* 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;
trx->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 < 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) {
ulint pos;
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5 + 15) {
return(0);
}
pos = dict_index_get_nth_col_pos(index,
col_no);
ptr += mach_write_compressed(ptr, pos);
/* Save the old value of field */
field = rec_get_nth_field(rec, offsets, pos,
&flen);
if (rec_offs_nth_extern(offsets, pos)) {
ptr = trx_undo_page_report_modify_ext(
ptr,
flen < REC_MAX_INDEX_COL_LEN
&& !ignore_prefix
? ext_buf : NULL,
dict_table_zip_size(table),
&field, &flen);
} 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;
}
}
}
mach_write_to_2(old_ptr, ptr - old_ptr);
}
/*----------------------------------------*/
/* 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);
}
ulint
row_get_trx_id_offset(
/*==================*/
const rec_t* rec __attribute__((unused)),
/*!< in: record */
dict_index_t* index, /*!< in: clustered index */
const ulint* offsets)/*!< in: rec_get_offsets(rec, index) */
{
ulint pos;
ulint offset;
ulint len;
ut_ad(dict_index_is_clust(index));
ut_ad(rec_offs_validate(rec, index, offsets));
pos = dict_index_get_sys_col_pos(index, DATA_TRX_ID);
offset = rec_get_nth_field_offs(offsets, pos, &len);
ut_ad(len == DATA_TRX_ID_LEN);
return(offset);
}
/*****************************************************************//**
When an insert or purge to a table is performed, this function builds
the entry to be inserted into or purged from an index on the table.
@return index entry which should be inserted or purged, or NULL if the
externally stored columns in the clustered index record are
unavailable and ext != NULL */
UNIV_INTERN
upd_t*
row_upd_build_difference_binary(
/*============================*/
/* out, own: update vector of differing
fields, excluding roll ptr and trx id */
dict_index_t* index, /* in: clustered index */
dtuple_t* entry, /* in: entry to insert */
ulint* ext_vec,/* in: array containing field numbers of
externally stored fields in entry, or NULL */
ulint n_ext_vec,/* in: number of fields in ext_vec */
rec_t* rec, /* in: clustered index record */
mem_heap_t* heap) /* in: memory heap from which allocated */
{
upd_field_t* upd_field;
dfield_t* dfield;
byte* data;
ulint len;
upd_t* update;
ulint n_diff;
ulint roll_ptr_pos;
ulint trx_id_pos;
ulint i;
/* This function is used only for a clustered index */
ut_a(index->type & DICT_CLUSTERED);
update = upd_create(dtuple_get_n_fields(entry), heap);
n_diff = 0;
roll_ptr_pos = dict_index_get_sys_col_pos(index, DATA_ROLL_PTR);
trx_id_pos = dict_index_get_sys_col_pos(index, DATA_TRX_ID);
for (i = 0; i < dtuple_get_n_fields(entry); i++) {
data = rec_get_nth_field(rec, i, &len);
dfield = dtuple_get_nth_field(entry, i);
/* NOTE: we compare the fields as binary strings!
(No collation) */
if (i == trx_id_pos || i == roll_ptr_pos) {
goto skip_compare;
}
if (rec_get_nth_field_extern_bit(rec, i)
!= upd_ext_vec_contains(ext_vec, n_ext_vec, i)
|| !dfield_data_is_binary_equal(dfield, len, data)) {
upd_field = upd_get_nth_field(update, n_diff);
dfield_copy(&(upd_field->new_val), dfield);
upd_field_set_field_no(upd_field, i, index);
if (upd_ext_vec_contains(ext_vec, n_ext_vec, i)) {
upd_field->extern_storage = TRUE;
} else {
upd_field->extern_storage = FALSE;
}
n_diff++;
}
skip_compare:
;
}
update->n_fields = n_diff;
return(update);
}
/**************************************************************************
Reports in the undo log of an update or delete marking of a clustered index
record. */
static
ulint
trx_undo_page_report_modify(
/*========================*/
/* out: byte offset of the inserted
undo log entry on the page if succeed,
0 if fail */
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 */
rec_t* rec, /* in: clustered index record which
has NOT yet been modified */
const ulint* offsets, /* in: rec_get_offsets(rec, index) */
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 */
mtr_t* mtr) /* in: mtr */
{
dict_table_t* table;
upd_field_t* upd_field;
ulint first_free;
byte* ptr;
ulint len;
byte* field;
ulint flen;
ulint pos;
dulint roll_ptr;
dulint trx_id;
ulint bits;
ulint col_no;
byte* old_ptr;
ulint type_cmpl;
byte* type_cmpl_ptr;
ulint i;
ut_a(index->type & DICT_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;
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) {
/* 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) {
if (rec_get_deleted_flag(rec, dict_table_is_comp(table))) {
type_cmpl = TRX_UNDO_UPD_DEL_REC;
} else {
type_cmpl = TRX_UNDO_UPD_EXIST_REC;
}
} else {
type_cmpl = TRX_UNDO_DEL_MARK_REC;
}
type_cmpl = type_cmpl | (cmpl_info * TRX_UNDO_CMPL_INFO_MULT);
mach_write_to_1(ptr, type_cmpl);
type_cmpl_ptr = ptr;
ptr++;
len = mach_dulint_write_much_compressed(ptr, trx->undo_no);
ptr += len;
len = mach_dulint_write_much_compressed(ptr, table->id);
ptr += len;
/*----------------------------------------*/
/* Store the state of the info bits */
bits = rec_get_info_bits(rec, dict_table_is_comp(table));
mach_write_to_1(ptr, bits);
ptr += 1;
/* Store the values of the system columns */
field = rec_get_nth_field(rec, offsets,
dict_index_get_sys_col_pos(
index, DATA_TRX_ID), &len);
ut_ad(len == DATA_TRX_ID_LEN);
trx_id = trx_read_trx_id(field);
field = rec_get_nth_field(rec, offsets,
dict_index_get_sys_col_pos(
index, DATA_ROLL_PTR), &len);
ut_ad(len == DATA_ROLL_PTR_LEN);
roll_ptr = trx_read_roll_ptr(field);
len = mach_dulint_write_compressed(ptr, trx_id);
ptr += len;
len = mach_dulint_write_compressed(ptr, roll_ptr);
ptr += len;
/*----------------------------------------*/
/* 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);
if (trx_undo_left(undo_page, ptr) < 4) {
return(0);
}
len = mach_write_compressed(ptr, flen);
ptr += len;
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);
}
len = mach_write_compressed(ptr, upd_get_n_fields(update));
ptr += len;
for (i = 0; i < upd_get_n_fields(update); i++) {
upd_field = upd_get_nth_field(update, i);
pos = upd_field->field_no;
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
len = mach_write_compressed(ptr, pos);
ptr += len;
/* Save the old value of field */
field = rec_get_nth_field(rec, offsets, pos, &flen);
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
if (rec_offs_nth_extern(offsets, pos)) {
/* If a field has external storage, we add
to flen the flag */
len = mach_write_compressed(
ptr,
UNIV_EXTERN_STORAGE_FIELD + flen);
/* Notify purge that it eventually has to
free the old externally stored field */
trx->update_undo->del_marks = TRUE;
*type_cmpl_ptr = *type_cmpl_ptr
| TRX_UNDO_UPD_EXTERN;
} else {
len = mach_write_compressed(ptr, flen);
}
ptr += len;
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr) < flen) {
return(0);
}
ut_memcpy(ptr, field, flen);
ptr += flen;
}
}
}
/*----------------------------------------*/
/* 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. But we always store at least
384 first bytes locally to the clustered index record, which means
we can construct the column prefix fields in the index from the
stored data. */
if (!update || !(cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
trx->update_undo->del_marks = TRUE;
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
old_ptr = ptr;
/* 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 > 0) {
pos = dict_index_get_nth_col_pos(index,
col_no);
/* Write field number to undo log */
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
len = mach_write_compressed(ptr, pos);
ptr += len;
/* Save the old value of field */
field = rec_get_nth_field(rec, offsets, pos,
&flen);
if (trx_undo_left(undo_page, ptr) < 5) {
return(0);
}
len = mach_write_compressed(ptr, flen);
ptr += len;
if (flen != UNIV_SQL_NULL) {
if (trx_undo_left(undo_page, ptr)
< flen) {
return(0);
}
ut_memcpy(ptr, field, flen);
ptr += flen;
}
}
}
mach_write_to_2(old_ptr, ptr - old_ptr);
}
/*----------------------------------------*/
/* 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);
}
