Ejemplo n.º 1
0
ibool
row_undo_search_clust_to_pcur(
/*==========================*/
				/* out: TRUE if found; NOTE the node->pcur
				must be closed by the caller, regardless of
				the return value */
	undo_node_t*	node)	/* in: row undo node */
{
	dict_index_t*	clust_index;
	ibool		found;
	mtr_t		mtr;
	ibool		ret;
	rec_t*		rec;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	mtr_start(&mtr);

	clust_index = dict_table_get_first_index(node->table);

	found = row_search_on_row_ref(&(node->pcur), BTR_MODIFY_LEAF,
				      node->table, node->ref, &mtr);

	rec = btr_pcur_get_rec(&(node->pcur));

	offsets = rec_get_offsets(rec, clust_index, offsets,
				  ULINT_UNDEFINED, &heap);

	if (!found || 0 != ut_dulint_cmp(node->roll_ptr,
					 row_get_rec_roll_ptr(rec, clust_index,
							      offsets))) {

		/* We must remove the reservation on the undo log record
		BEFORE releasing the latch on the clustered index page: this
		is to make sure that some thread will eventually undo the
		modification corresponding to node->roll_ptr. */

		/* fputs("--------------------undoing a previous version\n",
		stderr); */

		ret = FALSE;
	} else {
		node->row = row_build(ROW_COPY_DATA, clust_index, rec,
				      offsets, node->heap);
		btr_pcur_store_position(&(node->pcur), &mtr);

		ret = TRUE;
	}

	btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
	return(ret);
}
Ejemplo n.º 2
0
/***********************************************************//**
Undoes a modify in a clustered index record.
@return	DB_SUCCESS, DB_FAIL, or error code: we may run out of file space */
static
ulint
row_undo_mod_clust_low(
/*===================*/
	undo_node_t*	node,	/*!< in: row undo node */
	que_thr_t*	thr,	/*!< in: query thread */
	mtr_t*		mtr,	/*!< in: mtr; must be committed before
				latching any further pages */
	ulint		mode)	/*!< in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */
{
	btr_pcur_t*	pcur;
	btr_cur_t*	btr_cur;
	ulint		err;
#ifdef UNIV_DEBUG
	ibool		success;
#endif /* UNIV_DEBUG */

	pcur = &(node->pcur);
	btr_cur = btr_pcur_get_btr_cur(pcur);

#ifdef UNIV_DEBUG
	success =
#endif /* UNIV_DEBUG */
	btr_pcur_restore_position(mode, pcur, mtr);

	ut_ad(success);

	if (mode == BTR_MODIFY_LEAF) {

		err = btr_cur_optimistic_update(BTR_NO_LOCKING_FLAG
						| BTR_NO_UNDO_LOG_FLAG
						| BTR_KEEP_SYS_FLAG,
						btr_cur, node->update,
						node->cmpl_info, thr, mtr);
	} else {
		mem_heap_t*	heap		= NULL;
		big_rec_t*	dummy_big_rec;

		ut_ad(mode == BTR_MODIFY_TREE);

		err = btr_cur_pessimistic_update(
			BTR_NO_LOCKING_FLAG
			| BTR_NO_UNDO_LOG_FLAG
			| BTR_KEEP_SYS_FLAG,
			btr_cur, &heap, &dummy_big_rec, node->update,
			node->cmpl_info, thr, mtr);

		ut_a(!dummy_big_rec);
		if (UNIV_LIKELY_NULL(heap)) {
			mem_heap_free(heap);
		}
	}

	return(err);
}
Ejemplo n.º 3
0
/******************************************************************//**
Frees the free_block field from a memory heap. */
UNIV_INTERN
void
mem_heap_free_block_free(
/*=====================*/
	mem_heap_t*	heap)	/*!< in: heap */
{
	if (UNIV_LIKELY_NULL(heap->free_block)) {

		buf_block_free(heap->free_block);

		heap->free_block = NULL;
	}
}
Ejemplo n.º 4
0
/********************************************************//**
Parses a log record written by mlog_write_string.
@return	parsed record end, NULL if not a complete record */
UNIV_INTERN
byte*
mlog_parse_string(
/*==============*/
	byte*	ptr,	/*!< in: buffer */
	byte*	end_ptr,/*!< in: buffer end */
	byte*	page,	/*!< in: page where to apply the log record, or NULL */
	void*	page_zip)/*!< in/out: compressed page, or NULL */
{
	ulint	offset;
	ulint	len;

	ut_a(!page || !page_zip || fil_page_get_type(page) != FIL_PAGE_INDEX);

	if (end_ptr < ptr + 4) {

		return(NULL);
	}

	offset = mach_read_from_2(ptr);
	ptr += 2;
	len = mach_read_from_2(ptr);
	ptr += 2;

	if (UNIV_UNLIKELY(offset >= UNIV_PAGE_SIZE)
	    || UNIV_UNLIKELY(len + offset > UNIV_PAGE_SIZE)) {
		recv_sys->found_corrupt_log = TRUE;

		return(NULL);
	}

	if (end_ptr < ptr + len) {

		return(NULL);
	}

	if (page) {
		if (UNIV_LIKELY_NULL(page_zip)) {
			memcpy(((page_zip_des_t*) page_zip)->data
				+ offset, ptr, len);
		}
		memcpy(page + offset, ptr, len);
	}

	return(ptr + len);
}
Ejemplo n.º 5
0
/********************************************************//**
Parses a log record written by mlog_write_ulint or mlog_write_dulint.
@return	parsed record end, NULL if not a complete record or a corrupt record */
UNIV_INTERN
byte*
mlog_parse_nbytes(
/*==============*/
	ulint	type,	/*!< in: log record type: MLOG_1BYTE, ... */
	byte*	ptr,	/*!< in: buffer */
	byte*	end_ptr,/*!< in: buffer end */
	byte*	page,	/*!< in: page where to apply the log record, or NULL */
	void*	page_zip)/*!< in/out: compressed page, or NULL */
{
	ulint	offset;
	ulint	val;
	dulint	dval;

	ut_a(type <= MLOG_8BYTES);
	ut_a(!page || !page_zip || fil_page_get_type(page) != FIL_PAGE_INDEX);

	if (end_ptr < ptr + 2) {

		return(NULL);
	}

	offset = mach_read_from_2(ptr);
	ptr += 2;

	if (offset >= UNIV_PAGE_SIZE) {
		recv_sys->found_corrupt_log = TRUE;

		return(NULL);
	}

	if (type == MLOG_8BYTES) {
		ptr = mach_dulint_parse_compressed(ptr, end_ptr, &dval);

		if (ptr == NULL) {

			return(NULL);
		}

		if (page) {
			if (UNIV_LIKELY_NULL(page_zip)) {
				mach_write_to_8
					(((page_zip_des_t*) page_zip)->data
					 + offset, dval);
			}
			mach_write_to_8(page + offset, dval);
		}

		return(ptr);
	}

	ptr = mach_parse_compressed(ptr, end_ptr, &val);

	if (ptr == NULL) {

		return(NULL);
	}

	switch (type) {
	case MLOG_1BYTE:
		if (UNIV_UNLIKELY(val > 0xFFUL)) {
			goto corrupt;
		}
		if (page) {
			if (UNIV_LIKELY_NULL(page_zip)) {
				mach_write_to_1
					(((page_zip_des_t*) page_zip)->data
					 + offset, val);
			}
			mach_write_to_1(page + offset, val);
		}
		break;
	case MLOG_2BYTES:
		if (UNIV_UNLIKELY(val > 0xFFFFUL)) {
			goto corrupt;
		}
		if (page) {
			if (UNIV_LIKELY_NULL(page_zip)) {
				mach_write_to_2
					(((page_zip_des_t*) page_zip)->data
					 + offset, val);
			}
			mach_write_to_2(page + offset, val);
		}
		break;
	case MLOG_4BYTES:
		if (page) {
			if (UNIV_LIKELY_NULL(page_zip)) {
				mach_write_to_4
					(((page_zip_des_t*) page_zip)->data
					 + offset, val);
			}
			mach_write_to_4(page + offset, val);
		}
		break;
	default:
	corrupt:
		recv_sys->found_corrupt_log = TRUE;
		ptr = NULL;
	}

	return(ptr);
}
Ejemplo n.º 6
0
/*******************************************************************//**
Builds from a secondary index record a row reference with which we can
search the clustered index record. */
UNIV_INTERN
void
row_build_row_ref_in_tuple(
/*=======================*/
	dtuple_t*		ref,	/*!< in/out: row reference built;
					see the NOTE below! */
	const rec_t*		rec,	/*!< in: record in the index;
					NOTE: the data fields in ref
					will point directly into this
					record, therefore, the buffer
					page of this record must be at
					least s-latched and the latch
					held as long as the row
					reference is used! */
	const dict_index_t*	index,	/*!< in: secondary index */
	ulint*			offsets,/*!< in: rec_get_offsets(rec, index)
					or NULL */
	trx_t*			trx)	/*!< in: transaction */
{
	const dict_index_t*	clust_index;
	dfield_t*		dfield;
	const byte*		field;
	ulint			len;
	ulint			ref_len;
	ulint			pos;
	ulint			clust_col_prefix_len;
	ulint			i;
	mem_heap_t*		heap		= NULL;
	ulint			offsets_[REC_OFFS_NORMAL_SIZE];
	rec_offs_init(offsets_);

	ut_a(ref);
	ut_a(index);
	ut_a(rec);
	ut_ad(!dict_index_is_clust(index));

	if (UNIV_UNLIKELY(!index->table)) {
		fputs("InnoDB: table ", stderr);
notfound:
		ut_print_name(stderr, trx, TRUE, index->table_name);
		fputs(" for index ", stderr);
		ut_print_name(stderr, trx, FALSE, index->name);
		fputs(" not found\n", stderr);
		ut_error;
	}

	clust_index = dict_table_get_first_index(index->table);

	if (UNIV_UNLIKELY(!clust_index)) {
		fputs("InnoDB: clust index for table ", stderr);
		goto notfound;
	}

	if (!offsets) {
		offsets = rec_get_offsets(rec, index, offsets_,
					  ULINT_UNDEFINED, &heap);
	} else {
		ut_ad(rec_offs_validate(rec, index, offsets));
	}

	/* Secondary indexes must not contain externally stored columns. */
	ut_ad(!rec_offs_any_extern(offsets));
	ref_len = dict_index_get_n_unique(clust_index);

	ut_ad(ref_len == dtuple_get_n_fields(ref));

	dict_index_copy_types(ref, clust_index, ref_len);

	for (i = 0; i < ref_len; i++) {
		dfield = dtuple_get_nth_field(ref, i);

		pos = dict_index_get_nth_field_pos(index, clust_index, i);

		ut_a(pos != ULINT_UNDEFINED);

		field = rec_get_nth_field(rec, offsets, pos, &len);

		dfield_set_data(dfield, field, len);

		/* If the primary key contains a column prefix, then the
		secondary index may contain a longer prefix of the same
		column, or the full column, and we must adjust the length
		accordingly. */

		clust_col_prefix_len = dict_index_get_nth_field(
			clust_index, i)->prefix_len;

		if (clust_col_prefix_len > 0) {
			if (len != UNIV_SQL_NULL) {

				const dtype_t*	dtype
					= dfield_get_type(dfield);

				dfield_set_len(dfield,
					       dtype_get_at_most_n_mbchars(
						       dtype->prtype,
						       dtype->mbminlen,
						       dtype->mbmaxlen,
						       clust_col_prefix_len,
						       len, (char*) field));
			}
		}
	}

	ut_ad(dtuple_check_typed(ref));
	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
}
Ejemplo n.º 7
0
/*****************************************************************//**
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
dtuple_t*
row_build_index_entry(
/*==================*/
	const dtuple_t*	row,	/*!< in: row which should be
				inserted or purged */
	row_ext_t*	ext,	/*!< in: externally stored column prefixes,
				or NULL */
	dict_index_t*	index,	/*!< in: index on the table */
	mem_heap_t*	heap)	/*!< in: memory heap from which the memory for
				the index entry is allocated */
{
	dtuple_t*	entry;
	ulint		entry_len;
	ulint		i;

	ut_ad(row && index && heap);
	ut_ad(dtuple_check_typed(row));

	entry_len = dict_index_get_n_fields(index);
	entry = dtuple_create(heap, entry_len);

	if (UNIV_UNLIKELY(index->type & DICT_UNIVERSAL)) {
		dtuple_set_n_fields_cmp(entry, entry_len);
		/* There may only be externally stored columns
		in a clustered index B-tree of a user table. */
		ut_a(!ext);
	} else {
		dtuple_set_n_fields_cmp(
			entry, dict_index_get_n_unique_in_tree(index));
	}

	for (i = 0; i < entry_len; i++) {
		const dict_field_t*	ind_field
			= dict_index_get_nth_field(index, i);
		const dict_col_t*	col
			= ind_field->col;
		ulint			col_no
			= dict_col_get_no(col);
		dfield_t*		dfield
			= dtuple_get_nth_field(entry, i);
		const dfield_t*		dfield2
			= dtuple_get_nth_field(row, col_no);
		ulint			len
			= dfield_get_len(dfield2);

		dfield_copy(dfield, dfield2);

		if (dfield_is_null(dfield)) {
			continue;
		}

		if (ind_field->prefix_len == 0
		    && (!dfield_is_ext(dfield)
			|| dict_index_is_clust(index))) {
			/* The dfield_copy() above suffices for
			columns that are stored in-page, or for
			clustered index record columns that are not
			part of a column prefix in the PRIMARY KEY. */
			continue;
		}

		/* If the column is stored externally (off-page) in
		the clustered index, it must be an ordering field in
		the secondary index.  In the Antelope format, only
		prefix-indexed columns may be stored off-page in the
		clustered index record. In the Barracuda format, also
		fully indexed long CHAR or VARCHAR columns may be
		stored off-page. */
		ut_ad(col->ord_part);

		if (UNIV_LIKELY_NULL(ext)) {
			/* See if the column is stored externally. */
			const byte*	buf = row_ext_lookup(ext, col_no,
							     &len);
			if (UNIV_LIKELY_NULL(buf)) {
				if (UNIV_UNLIKELY(buf == field_ref_zero)) {
					return(NULL);
				}
				dfield_set_data(dfield, buf, len);
			}

			if (ind_field->prefix_len == 0) {
				/* In the Barracuda format
				(ROW_FORMAT=DYNAMIC or
				ROW_FORMAT=COMPRESSED), we can have a
				secondary index on an entire column
				that is stored off-page in the
				clustered index. As this is not a
				prefix index (prefix_len == 0),
				include the entire off-page column in
				the secondary index record. */
				continue;
			}
		} else if (dfield_is_ext(dfield)) {
			/* This table is either in Antelope format
			(ROW_FORMAT=REDUNDANT or ROW_FORMAT=COMPACT)
			or a purge record where the ordered part of
			the field is not external.
			In Antelope, the maximum column prefix
			index length is 767 bytes, and the clustered
			index record contains a 768-byte prefix of
			each off-page column. */
			ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
			len -= BTR_EXTERN_FIELD_REF_SIZE;
			dfield_set_len(dfield, len);
		}

		/* If a column prefix index, take only the prefix. */
		if (ind_field->prefix_len) {
			len = dtype_get_at_most_n_mbchars(
				col->prtype, col->mbminlen, col->mbmaxlen,
				ind_field->prefix_len, len,
				dfield_get_data(dfield));
			dfield_set_len(dfield, len);
		}
	}

	ut_ad(dtuple_check_typed(entry));

	return(entry);
}
Ejemplo n.º 8
0
/*******************************************************************//**
An inverse function to row_build_index_entry. Builds a row from a
record in a clustered index.
@return	own: row built; see the NOTE below! */
UNIV_INTERN
dtuple_t*
row_build(
/*======*/
	ulint			type,	/*!< in: ROW_COPY_POINTERS or
					ROW_COPY_DATA; the latter
					copies also the data fields to
					heap while the first only
					places pointers to data fields
					on the index page, and thus is
					more efficient */
	const dict_index_t*	index,	/*!< in: clustered index */
	const rec_t*		rec,	/*!< in: record in the clustered
					index; NOTE: in the case
					ROW_COPY_POINTERS the data
					fields in the row will point
					directly into this record,
					therefore, the buffer page of
					this record must be at least
					s-latched and the latch held
					as long as the row dtuple is used! */
	const ulint*		offsets,/*!< in: rec_get_offsets(rec,index)
					or NULL, in which case this function
					will invoke rec_get_offsets() */
	const dict_table_t*	col_table,
					/*!< in: table, to check which
					externally stored columns
					occur in the ordering columns
					of an index, or NULL if
					index->table should be
					consulted instead */
	row_ext_t**		ext,	/*!< out, own: cache of
					externally stored column
					prefixes, or NULL */
	mem_heap_t*		heap)	/*!< in: memory heap from which
					the memory needed is allocated */
{
	dtuple_t*		row;
	const dict_table_t*	table;
	ulint			n_fields;
	ulint			n_ext_cols;
	ulint*			ext_cols	= NULL; /* remove warning */
	ulint			len;
	ulint			row_len;
	byte*			buf;
	ulint			i;
	ulint			j;
	mem_heap_t*		tmp_heap	= NULL;
	ulint			offsets_[REC_OFFS_NORMAL_SIZE];
	rec_offs_init(offsets_);

	ut_ad(index && rec && heap);
	ut_ad(dict_index_is_clust(index));
	ut_ad(!mutex_own(&kernel_mutex));

	if (!offsets) {
		offsets = rec_get_offsets(rec, index, offsets_,
					  ULINT_UNDEFINED, &tmp_heap);
	} else {
		ut_ad(rec_offs_validate(rec, index, offsets));
	}

#if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
	if (rec_offs_any_null_extern(rec, offsets)) {
		/* This condition can occur during crash recovery
		before trx_rollback_active() has completed execution,
		or when a concurrently executing
		row_ins_index_entry_low() has committed the B-tree
		mini-transaction but has not yet managed to restore
		the cursor position for writing the big_rec. */
		ut_a(trx_undo_roll_ptr_is_insert(
			     row_get_rec_roll_ptr(rec, index, offsets)));
	}
#endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */

	if (type != ROW_COPY_POINTERS) {
		/* Take a copy of rec to heap */
		buf = mem_heap_alloc(heap, rec_offs_size(offsets));
		rec = rec_copy(buf, rec, offsets);
		/* Avoid a debug assertion in rec_offs_validate(). */
		rec_offs_make_valid(rec, index, (ulint*) offsets);
	}

	table = index->table;
	row_len = dict_table_get_n_cols(table);

	row = dtuple_create(heap, row_len);

	dict_table_copy_types(row, table);

	dtuple_set_info_bits(row, rec_get_info_bits(
				     rec, dict_table_is_comp(table)));

	n_fields = rec_offs_n_fields(offsets);
	n_ext_cols = rec_offs_n_extern(offsets);
	if (n_ext_cols) {
		ext_cols = mem_heap_alloc(heap, n_ext_cols * sizeof *ext_cols);
	}

	for (i = j = 0; i < n_fields; i++) {
		dict_field_t*		ind_field
			= dict_index_get_nth_field(index, i);
		const dict_col_t*	col
			= dict_field_get_col(ind_field);
		ulint			col_no
			= dict_col_get_no(col);
		dfield_t*		dfield
			= dtuple_get_nth_field(row, col_no);

		if (ind_field->prefix_len == 0) {

			const byte*	field = rec_get_nth_field(
				rec, offsets, i, &len);

			dfield_set_data(dfield, field, len);
		}

		if (rec_offs_nth_extern(offsets, i)) {
			dfield_set_ext(dfield);

			if (UNIV_LIKELY_NULL(col_table)) {
				ut_a(col_no
				     < dict_table_get_n_cols(col_table));
				col = dict_table_get_nth_col(
					col_table, col_no);
			}

			if (col->ord_part) {
				/* We will have to fetch prefixes of
				externally stored columns that are
				referenced by column prefixes. */
				ext_cols[j++] = col_no;
			}
		}
	}

	ut_ad(dtuple_check_typed(row));

	if (!ext) {
		/* REDUNDANT and COMPACT formats store a local
		768-byte prefix of each externally stored
		column. No cache is needed. */
		ut_ad(dict_table_get_format(index->table)
		      < DICT_TF_FORMAT_ZIP);
	} else if (j) {
		*ext = row_ext_create(j, ext_cols, row,
				      dict_table_zip_size(index->table),
				      heap);
	} else {
		*ext = NULL;
	}

	if (tmp_heap) {
		mem_heap_free(tmp_heap);
	}

	return(row);
}
Ejemplo n.º 9
0
/***********************************************************//**
Looks for the clustered index record when node has the row reference.
The pcur in node is used in the search. If found, stores the row to node,
and stores the position of pcur, and detaches it. The pcur must be closed
by the caller in any case.
@return TRUE if found; NOTE the node->pcur must be closed by the
caller, regardless of the return value */
UNIV_INTERN
ibool
row_undo_search_clust_to_pcur(
/*==========================*/
	undo_node_t*	node)	/*!< in: row undo node */
{
	dict_index_t*	clust_index;
	ibool		found;
	mtr_t		mtr;
	ibool		ret;
	rec_t*		rec;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	ulint*		offsets		= offsets_;
	rec_offs_init(offsets_);

	mtr_start(&mtr);

	clust_index = dict_table_get_first_index(node->table);

	found = row_search_on_row_ref(&(node->pcur), BTR_MODIFY_LEAF,
				      node->table, node->ref, &mtr);

	rec = btr_pcur_get_rec(&(node->pcur));

	offsets = rec_get_offsets(rec, clust_index, offsets,
				  ULINT_UNDEFINED, &heap);

	if (!found || 0 != ut_dulint_cmp(node->roll_ptr,
					 row_get_rec_roll_ptr(rec, clust_index,
							      offsets))) {

		/* We must remove the reservation on the undo log record
		BEFORE releasing the latch on the clustered index page: this
		is to make sure that some thread will eventually undo the
		modification corresponding to node->roll_ptr. */

		/* fputs("--------------------undoing a previous version\n",
		stderr); */

		ret = FALSE;
	} else {
		row_ext_t**	ext;

		if (dict_table_get_format(node->table) >= DICT_TF_FORMAT_ZIP) {
			/* In DYNAMIC or COMPRESSED format, there is
			no prefix of externally stored columns in the
			clustered index record. Build a cache of
			column prefixes. */
			ext = &node->ext;
		} else {
			/* REDUNDANT and COMPACT formats store a local
			768-byte prefix of each externally stored
			column. No cache is needed. */
			ext = NULL;
			node->ext = NULL;
		}

		node->row = row_build(ROW_COPY_DATA, clust_index, rec,
				      offsets, NULL, ext, node->heap);
		if (node->update) {
			node->undo_row = dtuple_copy(node->row, node->heap);
			row_upd_replace(node->undo_row, &node->undo_ext,
					clust_index, node->update, node->heap);
		} else {
			node->undo_row = NULL;
			node->undo_ext = NULL;
		}

		btr_pcur_store_position(&(node->pcur), &mtr);

		ret = TRUE;
	}

	btr_pcur_commit_specify_mtr(&(node->pcur), &mtr);

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}
	return(ret);
}
Ejemplo n.º 10
0
/***********************************************************//**
Removes a delete marked clustered index record if possible.
@return TRUE if success, or if not found, or if modified after the
delete marking */
static
ibool
row_purge_remove_clust_if_poss_low(
    /*===============================*/
    purge_node_t*	node,	/*!< in: row purge node */
    ulint		mode)	/*!< in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */
{
    dict_index_t*	index;
    btr_pcur_t*	pcur;
    btr_cur_t*	btr_cur;
    ibool		success;
    ulint		err;
    mtr_t		mtr;
    rec_t*		rec;
    mem_heap_t*	heap		= NULL;
    ulint		offsets_[REC_OFFS_NORMAL_SIZE];
    rec_offs_init(offsets_);

    index = dict_table_get_first_index(node->table);

    pcur = &(node->pcur);
    btr_cur = btr_pcur_get_btr_cur(pcur);

    log_free_check();
    mtr_start(&mtr);

    success = row_purge_reposition_pcur(mode, node, &mtr);

    if (!success) {
        /* The record is already removed */

        btr_pcur_commit_specify_mtr(pcur, &mtr);

        return(TRUE);
    }

    rec = btr_pcur_get_rec(pcur);

    if (node->roll_ptr != row_get_rec_roll_ptr(
                rec, index, rec_get_offsets(rec, index, offsets_,
                                            ULINT_UNDEFINED, &heap))) {
        if (UNIV_LIKELY_NULL(heap)) {
            mem_heap_free(heap);
        }
        /* Someone else has modified the record later: do not remove */
        btr_pcur_commit_specify_mtr(pcur, &mtr);

        return(TRUE);
    }

    if (UNIV_LIKELY_NULL(heap)) {
        mem_heap_free(heap);
    }

    if (mode == BTR_MODIFY_LEAF) {
        success = btr_cur_optimistic_delete(btr_cur, &mtr);
    } else {
        ut_ad(mode == BTR_MODIFY_TREE);
        btr_cur_pessimistic_delete(&err, FALSE, btr_cur,
                                   RB_NONE, &mtr);

        if (err == DB_SUCCESS) {
            success = TRUE;
        } else if (err == DB_OUT_OF_FILE_SPACE) {
            success = FALSE;
        } else {
            ut_error;
        }
    }

    btr_pcur_commit_specify_mtr(pcur, &mtr);

    return(success);
}