inline ibool check_fields_sizes(rec_t *rec, table_def_t *table, ulint *offsets) {
	int i;

	if (debug) {
		printf("\nChecking field lengths for a row (%s): ", table->name);
		printf("OFFSETS: ");
		for(i = 0; i < rec_offs_n_fields(offsets); i++) {
			printf("%lu ", rec_offs_base(offsets)[i]);
		}
//		printf("\n");
	}
	
	// check every field
	for(i = 0; i < table->fields_count; i++) {
		// Get field size
		ulint len = rec_offs_nth_size(offsets, i);
		if (debug) printf("\n - field %s(%lu):", table->fields[i].name, len);
		
		// If field is null
		if (len == UNIV_SQL_NULL) {
			// Check if it can be null and jump to a next field if it is OK
			if (table->fields[i].can_be_null) continue;
			// Invalid record where non-nullable field is NULL
			if (debug) printf("Can't be NULL or zero-length!\n");
			return FALSE;
		} 
		
		// Check size of fixed-length field
		if (table->fields[i].fixed_length) {
			// Check if size is the same and jump to the next field if it is OK
			if (len == table->fields[i].fixed_length || (len == 0 && table->fields[i].can_be_null)) continue;
			// Invalid fixed length field
			if (debug) printf("Invalid fixed length field size: %lu, but should be %u!\n", len, table->fields[i].fixed_length);
			return FALSE;
		}
		
		// Check if has externally stored data 
		if (rec_offs_nth_extern(offsets, i)) {
			if (debug) printf("\nEXTERNALLY STORED VALUE FOUND in field %i\n", i);
			if (table->fields[i].type == FT_TEXT || table->fields[i].type == FT_BLOB) continue;
			if (debug) printf("Invalid external data flag!\n");
			return FALSE;
		}
		
		// Check size limits for varlen fields
		if (len < table->fields[i].min_length || len > table->fields[i].max_length) {
			if (debug) printf("Length limits check failed (%lu < %u || %lu > %u)!\n", len, table->fields[i].min_length, len, table->fields[i].max_length);
			return FALSE;
		}

		if (debug) printf("OK!");
	}

	if (debug) printf("\n");
	return TRUE;
}
Example #2
0
/*******************************************************************//**
Converts an index record to a typed data tuple.
@return index entry built; does not set info_bits, and the data fields
in the entry will point directly to rec */
UNIV_INTERN
dtuple_t*
row_rec_to_index_entry_low(
/*=======================*/
	const rec_t*		rec,	/*!< in: record in the index */
	const dict_index_t*	index,	/*!< in: index */
	const ulint*		offsets,/*!< in: rec_get_offsets(rec, index) */
	ulint*			n_ext,	/*!< out: number of externally
					stored columns */
	mem_heap_t*		heap)	/*!< in: memory heap from which
					the memory needed is allocated */
{
	dtuple_t*	entry;
	dfield_t*	dfield;
	ulint		i;
	const byte*	field;
	ulint		len;
	ulint		rec_len;

	ut_ad(rec && heap && index);
	/* Because this function may be invoked by row0merge.c
	on a record whose header is in different format, the check
	rec_offs_validate(rec, index, offsets) must be avoided here. */
	ut_ad(n_ext);
	*n_ext = 0;

	rec_len = rec_offs_n_fields(offsets);

	entry = dtuple_create(heap, rec_len);

	dtuple_set_n_fields_cmp(entry,
				dict_index_get_n_unique_in_tree(index));
	ut_ad(rec_len == dict_index_get_n_fields(index));

	dict_index_copy_types(entry, index, rec_len);

	for (i = 0; i < rec_len; i++) {

		dfield = dtuple_get_nth_field(entry, i);
		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);
			(*n_ext)++;
		}
	}

	ut_ad(dtuple_check_typed(entry));

	return(entry);
}
Example #3
0
ulint process_ibrec(page_t *page, rec_t *rec, table_def_t *table, ulint *offsets) {
	ulint data_size;
	int i;
	// Print trx_id and rollback pointer
	for(i = 0; i < table->fields_count; i++) {
		ulint len;
		byte *field = rec_get_nth_field(rec, offsets, i, &len);
		
		if (table->fields[i].type == FT_INTERNAL){
			if (debug) printf("Field #%i @ %p: length %lu, value: ", i, field, len);
			print_field_value(field, len, &(table->fields[i]));
			if (i < table->fields_count - 1) fprintf(f_result, "\t");
			if (debug) printf("\n");
			}
	}

	// Print table name
	if (debug) {
		printf("Processing record %p from table '%s'\n", rec, table->name);
		rec_print_new(stdout, rec, offsets);
	} else {
		fprintf(f_result, "%s\t", table->name);
	}

	data_size = rec_offs_data_size(offsets);

	for(i = 0; i < table->fields_count; i++) {
		ulint len;
		byte *field = rec_get_nth_field(rec, offsets, i, &len);
		
		if (table->fields[i].type == FT_INTERNAL) continue;
		
		if (debug) printf("Field #%i @ %p: length %lu, value: ", i, field, len);

		if (len == UNIV_SQL_NULL) {
			fprintf(f_result, "NULL");
		} else {
            if (rec_offs_nth_extern(offsets, i)) {
                print_field_value_with_external(field, len, &(table->fields[i]));
                } else {
			        print_field_value(field, len, &(table->fields[i]));
                    }
		    }
		
		if (i < table->fields_count - 1) fprintf(f_result, "\t");
		if (debug) printf("\n");
	}

	fprintf(f_result, "\n");
	return data_size; // point to the next possible record's start
}
Example #4
0
/**********************************************************************//**
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);
}
Example #5
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);
}
Example #6
0
/*************************************************************//**
This function is used to compare two physical records. Only the common
first fields are compared, and if an externally stored field is
encountered, then 0 is returned.
@return 1, 0, -1 if rec1 is greater, equal, less, respectively */
UNIV_INTERN
int
cmp_rec_rec_with_match(
/*===================*/
	const rec_t*	rec1,	/*!< in: physical record */
	const rec_t*	rec2,	/*!< in: physical record */
	const ulint*	offsets1,/*!< in: rec_get_offsets(rec1, index) */
	const ulint*	offsets2,/*!< in: rec_get_offsets(rec2, index) */
	dict_index_t*	index,	/*!< in: data dictionary index */
	ulint*		matched_fields, /*!< in/out: number of already completely
				matched fields; when the function returns,
				contains the value the for current
				comparison */
	ulint*		matched_bytes) /*!< in/out: number of already matched
				bytes within the first field not completely
				matched; when the function returns, contains
				the value for the current comparison */
{
	ulint		rec1_n_fields;	/* the number of fields in rec */
	ulint		rec1_f_len;	/* length of current field in rec */
	const byte*	rec1_b_ptr;	/* pointer to the current byte
					in rec field */
	ulint		rec1_byte;	/* value of current byte to be
					compared in rec */
	ulint		rec2_n_fields;	/* the number of fields in rec */
	ulint		rec2_f_len;	/* length of current field in rec */
	const byte*	rec2_b_ptr;	/* pointer to the current byte
					in rec field */
	ulint		rec2_byte;	/* value of current byte to be
					compared in rec */
	ulint		cur_field;	/* current field number */
	ulint		cur_bytes;	/* number of already matched
					bytes in current field */
	int		ret = 0;	/* return value */
	ulint		comp;

	ut_ad(rec1 && rec2 && index);
	ut_ad(rec_offs_validate(rec1, index, offsets1));
	ut_ad(rec_offs_validate(rec2, index, offsets2));
	ut_ad(rec_offs_comp(offsets1) == rec_offs_comp(offsets2));

	comp = rec_offs_comp(offsets1);
	rec1_n_fields = rec_offs_n_fields(offsets1);
	rec2_n_fields = rec_offs_n_fields(offsets2);

	cur_field = *matched_fields;
	cur_bytes = *matched_bytes;

	/* Match fields in a loop */

	while ((cur_field < rec1_n_fields) && (cur_field < rec2_n_fields)) {

		ulint	mtype;
		ulint	prtype;

		if (UNIV_UNLIKELY(index->type & DICT_UNIVERSAL)) {
			/* This is for the insert buffer B-tree. */
			mtype = DATA_BINARY;
			prtype = 0;
		} else {
			const dict_col_t*	col
				= dict_index_get_nth_col(index, cur_field);

			mtype = col->mtype;
			prtype = col->prtype;
		}

		rec1_b_ptr = rec_get_nth_field(rec1, offsets1,
					       cur_field, &rec1_f_len);
		rec2_b_ptr = rec_get_nth_field(rec2, offsets2,
					       cur_field, &rec2_f_len);

		if (cur_bytes == 0) {
			if (cur_field == 0) {
				/* Test if rec is the predefined minimum
				record */
				if (UNIV_UNLIKELY(rec_get_info_bits(rec1, comp)
						  & REC_INFO_MIN_REC_FLAG)) {

					if (!(rec_get_info_bits(rec2, comp)
					      & REC_INFO_MIN_REC_FLAG)) {
						ret = -1;
					}

					goto order_resolved;

				} else if (UNIV_UNLIKELY
					   (rec_get_info_bits(rec2, comp)
					    & REC_INFO_MIN_REC_FLAG)) {

					ret = 1;

					goto order_resolved;
				}
			}

			if (rec_offs_nth_extern(offsets1, cur_field)
			    || rec_offs_nth_extern(offsets2, cur_field)) {
				/* We do not compare to an externally
				stored field */

				goto order_resolved;
			}

			if (rec1_f_len == UNIV_SQL_NULL
			    || rec2_f_len == UNIV_SQL_NULL) {

				if (rec1_f_len == rec2_f_len) {

					goto next_field;

				} else if (rec2_f_len == UNIV_SQL_NULL) {

					/* We define the SQL null to be the
					smallest possible value of a field
					in the alphabetical order */

					ret = 1;
				} else {
					ret = -1;
				}

				goto order_resolved;
			}
		}

		if (mtype >= DATA_FLOAT
		    || (mtype == DATA_BLOB
			&& 0 == (prtype & DATA_BINARY_TYPE)
			&& dtype_get_charset_coll(prtype)
			!= DATA_MYSQL_LATIN1_SWEDISH_CHARSET_COLL)) {

			ret = cmp_whole_field(mtype, prtype,
					      rec1_b_ptr,
					      (unsigned) rec1_f_len,
					      rec2_b_ptr,
					      (unsigned) rec2_f_len);
			if (ret != 0) {
				cur_bytes = 0;

				goto order_resolved;
			} else {
				goto next_field;
			}
		}

		/* Set the pointers at the current byte */
		rec1_b_ptr = rec1_b_ptr + cur_bytes;
		rec2_b_ptr = rec2_b_ptr + cur_bytes;

		/* Compare then the fields */
		for (;;) {
			if (rec2_f_len <= cur_bytes) {

				if (rec1_f_len <= cur_bytes) {

					goto next_field;
				}

				rec2_byte = dtype_get_pad_char(mtype, prtype);

				if (rec2_byte == ULINT_UNDEFINED) {
					ret = 1;

					goto order_resolved;
				}
			} else {
				rec2_byte = *rec2_b_ptr;
			}

			if (rec1_f_len <= cur_bytes) {
				rec1_byte = dtype_get_pad_char(mtype, prtype);

				if (rec1_byte == ULINT_UNDEFINED) {
					ret = -1;

					goto order_resolved;
				}
			} else {
				rec1_byte = *rec1_b_ptr;
			}

			if (rec1_byte == rec2_byte) {
				/* If the bytes are equal, they will remain
				such even after the collation transformation
				below */

				goto next_byte;
			}

			if (mtype <= DATA_CHAR
			    || (mtype == DATA_BLOB
				&& !(prtype & DATA_BINARY_TYPE))) {

				rec1_byte = cmp_collate(rec1_byte);
				rec2_byte = cmp_collate(rec2_byte);
			}

			if (rec1_byte < rec2_byte) {
				ret = -1;
				goto order_resolved;
			} else if (rec1_byte > rec2_byte) {
				ret = 1;
				goto order_resolved;
			}
next_byte:
			/* Next byte */

			cur_bytes++;
			rec1_b_ptr++;
			rec2_b_ptr++;
		}

next_field:
		cur_field++;
		cur_bytes = 0;
	}

	ut_ad(cur_bytes == 0);

	/* If we ran out of fields, rec1 was equal to rec2 up
	to the common fields */
	ut_ad(ret == 0);
order_resolved:

	ut_ad((ret >= - 1) && (ret <= 1));

	*matched_fields = cur_field;
	*matched_bytes = cur_bytes;

	return(ret);
}
Example #7
0
/*************************************************************//**
Compare two physical records that contain the same number of columns,
none of which are stored externally.
@return	1, 0, -1 if rec1 is greater, equal, less, respectively, than rec2 */
UNIV_INTERN
int
cmp_rec_rec_simple(
/*===============*/
	const rec_t*		rec1,	/*!< in: physical record */
	const rec_t*		rec2,	/*!< in: physical record */
	const ulint*		offsets1,/*!< in: rec_get_offsets(rec1, ...) */
	const ulint*		offsets2,/*!< in: rec_get_offsets(rec2, ...) */
	const dict_index_t*	index)	/*!< in: data dictionary index */
{
	ulint		rec1_f_len;	/*!< length of current field in rec1 */
	const byte*	rec1_b_ptr;	/*!< pointer to the current byte
					in rec1 field */
	ulint		rec1_byte;	/*!< value of current byte to be
					compared in rec1 */
	ulint		rec2_f_len;	/*!< length of current field in rec2 */
	const byte*	rec2_b_ptr;	/*!< pointer to the current byte
					in rec2 field */
	ulint		rec2_byte;	/*!< value of current byte to be
					compared in rec2 */
	ulint		cur_field;	/*!< current field number */
	ulint		n_uniq;

	n_uniq = dict_index_get_n_unique(index);
	ut_ad(rec_offs_n_fields(offsets1) >= n_uniq);
	ut_ad(rec_offs_n_fields(offsets2) >= n_uniq);

	ut_ad(rec_offs_comp(offsets1) == rec_offs_comp(offsets2));

	for (cur_field = 0; cur_field < n_uniq; cur_field++) {

		ulint	cur_bytes;
		ulint	mtype;
		ulint	prtype;

		{
			const dict_col_t*	col
				= dict_index_get_nth_col(index, cur_field);

			mtype = col->mtype;
			prtype = col->prtype;
		}

		ut_ad(!rec_offs_nth_extern(offsets1, cur_field));
		ut_ad(!rec_offs_nth_extern(offsets2, cur_field));

		rec1_b_ptr = rec_get_nth_field(rec1, offsets1,
					       cur_field, &rec1_f_len);
		rec2_b_ptr = rec_get_nth_field(rec2, offsets2,
					       cur_field, &rec2_f_len);

		if (rec1_f_len == UNIV_SQL_NULL
		    || rec2_f_len == UNIV_SQL_NULL) {

			if (rec1_f_len == rec2_f_len) {

				goto next_field;

			} else if (rec2_f_len == UNIV_SQL_NULL) {

				/* We define the SQL null to be the
				smallest possible value of a field
				in the alphabetical order */

				return(1);
			} else {
				return(-1);
			}
		}

		if (mtype >= DATA_FLOAT
		    || (mtype == DATA_BLOB
			&& 0 == (prtype & DATA_BINARY_TYPE)
			&& dtype_get_charset_coll(prtype)
			!= DATA_MYSQL_LATIN1_SWEDISH_CHARSET_COLL)) {
			int ret = cmp_whole_field(mtype, prtype,
						  rec1_b_ptr,
						  (unsigned) rec1_f_len,
						  rec2_b_ptr,
						  (unsigned) rec2_f_len);
			if (ret) {
				return(ret);
			}

			goto next_field;
		}

		/* Compare the fields */
		for (cur_bytes = 0;; cur_bytes++, rec1_b_ptr++, rec2_b_ptr++) {
			if (rec2_f_len <= cur_bytes) {

				if (rec1_f_len <= cur_bytes) {

					goto next_field;
				}

				rec2_byte = dtype_get_pad_char(mtype, prtype);

				if (rec2_byte == ULINT_UNDEFINED) {
					return(1);
				}
			} else {
				rec2_byte = *rec2_b_ptr;
			}

			if (rec1_f_len <= cur_bytes) {
				rec1_byte = dtype_get_pad_char(mtype, prtype);

				if (rec1_byte == ULINT_UNDEFINED) {
					return(-1);
				}
			} else {
				rec1_byte = *rec1_b_ptr;
			}

			if (rec1_byte == rec2_byte) {
				/* If the bytes are equal, they will remain
				such even after the collation transformation
				below */

				continue;
			}

			if (mtype <= DATA_CHAR
			    || (mtype == DATA_BLOB
				&& !(prtype & DATA_BINARY_TYPE))) {

				rec1_byte = cmp_collate(rec1_byte);
				rec2_byte = cmp_collate(rec2_byte);
			}

			if (rec1_byte < rec2_byte) {
				return(-1);
			} else if (rec1_byte > rec2_byte) {
				return(1);
			}
		}
next_field:
		continue;
	}

	/* If we ran out of fields, rec1 was equal to rec2. */
	return(0);
}
Example #8
0
/*************************************************************//**
This function is used to compare a data tuple to a physical record.
Only dtuple->n_fields_cmp first fields are taken into account for
the data tuple! If we denote by n = n_fields_cmp, then rec must
have either m >= n fields, or it must differ from dtuple in some of
the m fields rec has. If rec has an externally stored field we do not
compare it but return with value 0 if such a comparison should be
made.
@return 1, 0, -1, if dtuple is greater, equal, less than rec,
respectively, when only the common first fields are compared, or until
the first externally stored field in rec */
UNIV_INTERN
int
cmp_dtuple_rec_with_match(
/*======================*/
	const dtuple_t*	dtuple,	/*!< in: data tuple */
	const rec_t*	rec,	/*!< in: physical record which differs from
				dtuple in some of the common fields, or which
				has an equal number or more fields than
				dtuple */
	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
	ulint*		matched_fields, /*!< in/out: number of already completely
				matched fields; when function returns,
				contains the value for current comparison */
	ulint*		matched_bytes) /*!< in/out: number of already matched
				bytes within the first field not completely
				matched; when function returns, contains the
				value for current comparison */
{
	const dfield_t*	dtuple_field;	/* current field in logical record */
	ulint		dtuple_f_len;	/* the length of the current field
					in the logical record */
	const byte*	dtuple_b_ptr;	/* pointer to the current byte in
					logical field data */
	ulint		dtuple_byte;	/* value of current byte to be compared
					in dtuple*/
	ulint		rec_f_len;	/* length of current field in rec */
	const byte*	rec_b_ptr;	/* pointer to the current byte in
					rec field */
	ulint		rec_byte;	/* value of current byte to be
					compared in rec */
	ulint		cur_field;	/* current field number */
	ulint		cur_bytes;	/* number of already matched bytes
					in current field */
	int		ret = 3333;	/* return value */

	ut_ad(dtuple && rec && matched_fields && matched_bytes);
	ut_ad(dtuple_check_typed(dtuple));
	ut_ad(rec_offs_validate(rec, NULL, offsets));

	cur_field = *matched_fields;
	cur_bytes = *matched_bytes;

	ut_ad(cur_field <= dtuple_get_n_fields_cmp(dtuple));
	ut_ad(cur_field <= rec_offs_n_fields(offsets));

	if (cur_bytes == 0 && cur_field == 0) {
		ulint	rec_info = rec_get_info_bits(rec,
						     rec_offs_comp(offsets));
		ulint	tup_info = dtuple_get_info_bits(dtuple);

		if (UNIV_UNLIKELY(rec_info & REC_INFO_MIN_REC_FLAG)) {
			ret = !(tup_info & REC_INFO_MIN_REC_FLAG);
			goto order_resolved;
		} else if (UNIV_UNLIKELY(tup_info & REC_INFO_MIN_REC_FLAG)) {
			ret = -1;
			goto order_resolved;
		}
	}

	/* Match fields in a loop; stop if we run out of fields in dtuple
	or find an externally stored field */

	while (cur_field < dtuple_get_n_fields_cmp(dtuple)) {

		ulint	mtype;
		ulint	prtype;

		dtuple_field = dtuple_get_nth_field(dtuple, cur_field);
		{
			const dtype_t*	type
				= dfield_get_type(dtuple_field);

			mtype = type->mtype;
			prtype = type->prtype;
		}

		dtuple_f_len = dfield_get_len(dtuple_field);

		rec_b_ptr = rec_get_nth_field(rec, offsets,
					      cur_field, &rec_f_len);

		/* If we have matched yet 0 bytes, it may be that one or
		both the fields are SQL null, or the record or dtuple may be
		the predefined minimum record, or the field is externally
		stored */

		if (UNIV_LIKELY(cur_bytes == 0)) {
			if (rec_offs_nth_extern(offsets, cur_field)) {
				/* We do not compare to an externally
				stored field */

				ret = 0;

				goto order_resolved;
			}

			if (dtuple_f_len == UNIV_SQL_NULL) {
				if (rec_f_len == UNIV_SQL_NULL) {

					goto next_field;
				}

				ret = -1;
				goto order_resolved;
			} else if (rec_f_len == UNIV_SQL_NULL) {
				/* We define the SQL null to be the
				smallest possible value of a field
				in the alphabetical order */

				ret = 1;
				goto order_resolved;
			}
		}

		if (mtype >= DATA_FLOAT
		    || (mtype == DATA_BLOB
			&& 0 == (prtype & DATA_BINARY_TYPE)
			&& dtype_get_charset_coll(prtype)
			!= DATA_MYSQL_LATIN1_SWEDISH_CHARSET_COLL)) {

			ret = cmp_whole_field(mtype, prtype,
					      dfield_get_data(dtuple_field),
					      (unsigned) dtuple_f_len,
					      rec_b_ptr, (unsigned) rec_f_len);

			if (ret != 0) {
				cur_bytes = 0;

				goto order_resolved;
			} else {
				goto next_field;
			}
		}

		/* Set the pointers at the current byte */

		rec_b_ptr = rec_b_ptr + cur_bytes;
		dtuple_b_ptr = (byte*)dfield_get_data(dtuple_field)
			+ cur_bytes;
		/* Compare then the fields */

		for (;;) {
			if (UNIV_UNLIKELY(rec_f_len <= cur_bytes)) {
				if (dtuple_f_len <= cur_bytes) {

					goto next_field;
				}

				rec_byte = dtype_get_pad_char(mtype, prtype);

				if (rec_byte == ULINT_UNDEFINED) {
					ret = 1;

					goto order_resolved;
				}
			} else {
				rec_byte = *rec_b_ptr;
			}

			if (UNIV_UNLIKELY(dtuple_f_len <= cur_bytes)) {
				dtuple_byte = dtype_get_pad_char(mtype,
								 prtype);

				if (dtuple_byte == ULINT_UNDEFINED) {
					ret = -1;

					goto order_resolved;
				}
			} else {
				dtuple_byte = *dtuple_b_ptr;
			}

			if (dtuple_byte == rec_byte) {
				/* If the bytes are equal, they will
				remain such even after the collation
				transformation below */

				goto next_byte;
			}

			if (mtype <= DATA_CHAR
			    || (mtype == DATA_BLOB
				&& !(prtype & DATA_BINARY_TYPE))) {

				rec_byte = cmp_collate(rec_byte);
				dtuple_byte = cmp_collate(dtuple_byte);
			}

			ret = (int) (dtuple_byte - rec_byte);
			if (UNIV_LIKELY(ret)) {
				if (ret < 0) {
					ret = -1;
					goto order_resolved;
				} else {
					ret = 1;
					goto order_resolved;
				}
			}
next_byte:
			/* Next byte */
			cur_bytes++;
			rec_b_ptr++;
			dtuple_b_ptr++;
		}

next_field:
		cur_field++;
		cur_bytes = 0;
	}

	ut_ad(cur_bytes == 0);

	ret = 0;	/* If we ran out of fields, dtuple was equal to rec
			up to the common fields */
order_resolved:
	ut_ad((ret >= - 1) && (ret <= 1));
	ut_ad(ret == cmp_debug_dtuple_rec_with_match(dtuple, rec, offsets,
						     matched_fields));
	ut_ad(*matched_fields == cur_field); /* In the debug version, the
					     above cmp_debug_... sets
					     *matched_fields to a value */
	*matched_fields = cur_field;
	*matched_bytes = cur_bytes;

	return(ret);
}
Example #9
0
/*************************************************************//**
Used in debug checking of cmp_dtuple_... .
This function is used to compare a data tuple to a physical record. If
dtuple has n fields then rec must have either m >= n fields, or it must
differ from dtuple in some of the m fields rec has. If encounters an
externally stored field, returns 0.
@return 1, 0, -1, if dtuple is greater, equal, less than rec,
respectively, when only the common first fields are compared */
static
int
cmp_debug_dtuple_rec_with_match(
/*============================*/
	const dtuple_t*	dtuple,	/*!< in: data tuple */
	const rec_t*	rec,	/*!< in: physical record which differs from
				dtuple in some of the common fields, or which
				has an equal number or more fields than
				dtuple */
	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
	ulint*		matched_fields) /*!< in/out: number of already
				completely matched fields; when function
				returns, contains the value for current
				comparison */
{
	const dfield_t*	dtuple_field;	/* current field in logical record */
	ulint		dtuple_f_len;	/* the length of the current field
					in the logical record */
	const byte*	dtuple_f_data;	/* pointer to the current logical
					field data */
	ulint		rec_f_len;	/* length of current field in rec */
	const byte*	rec_f_data;	/* pointer to the current rec field */
	int		ret = 3333;	/* return value */
	ulint		cur_field;	/* current field number */

	ut_ad(dtuple && rec && matched_fields);
	ut_ad(dtuple_check_typed(dtuple));
	ut_ad(rec_offs_validate(rec, NULL, offsets));

	ut_ad(*matched_fields <= dtuple_get_n_fields_cmp(dtuple));
	ut_ad(*matched_fields <= rec_offs_n_fields(offsets));

	cur_field = *matched_fields;

	if (cur_field == 0) {
		if (UNIV_UNLIKELY
		    (rec_get_info_bits(rec, rec_offs_comp(offsets))
		     & REC_INFO_MIN_REC_FLAG)) {

			ret = !(dtuple_get_info_bits(dtuple)
				& REC_INFO_MIN_REC_FLAG);

			goto order_resolved;
		}

		if (UNIV_UNLIKELY
		    (dtuple_get_info_bits(dtuple) & REC_INFO_MIN_REC_FLAG)) {
			ret = -1;

			goto order_resolved;
		}
	}

	/* Match fields in a loop; stop if we run out of fields in dtuple */

	while (cur_field < dtuple_get_n_fields_cmp(dtuple)) {

		ulint	mtype;
		ulint	prtype;

		dtuple_field = dtuple_get_nth_field(dtuple, cur_field);
		{
			const dtype_t*	type
				= dfield_get_type(dtuple_field);

			mtype = type->mtype;
			prtype = type->prtype;
		}

		dtuple_f_data = dfield_get_data(dtuple_field);
		dtuple_f_len = dfield_get_len(dtuple_field);

		rec_f_data = rec_get_nth_field(rec, offsets,
					       cur_field, &rec_f_len);

		if (rec_offs_nth_extern(offsets, cur_field)) {
			/* We do not compare to an externally stored field */

			ret = 0;

			goto order_resolved;
		}

		ret = cmp_data_data(mtype, prtype, dtuple_f_data, dtuple_f_len,
				    rec_f_data, rec_f_len);
		if (ret != 0) {
			goto order_resolved;
		}

		cur_field++;
	}

	ret = 0;	/* If we ran out of fields, dtuple was equal to rec
			up to the common fields */
order_resolved:
	ut_ad((ret >= - 1) && (ret <= 1));

	*matched_fields = cur_field;

	return(ret);
}
Example #10
0
/**************************************************************************
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);
}