rem0wrec.h File Reference

Record manager wrapper declaration. More...

#include "rem/rec.h"

Go to the source code of this file.

Functions
byte *	rec_get_nth_field (const dict_index_t *index, const rec_t *rec, const ulint *offsets, ulint n, ulint *len)
	Gets the value of the specified field in the record. More...
const byte *	rec_get_nth_field_old (const dict_index_t *index, const rec_t *rec, ulint n, ulint *len)
ulint	rec_get_nth_field_size (const dict_index_t *index, const rec_t *rec, ulint n)
	Gets the physical size of an old-style field. More...
ulint	rec_get_nth_field_offs (const dict_index_t *index, const ulint *offsets, ulint n, ulint *len)
	The following function is used to get an offset to the nth data field in a record. More...
ulint	rec_get_nth_field_offs_old (const dict_index_t *index, const rec_t *rec, ulint n, ulint *len)
	The following function is used to get the offset to the nth data field in an old-style record. More...
ulint	rec_offs_nth_extern (const dict_index_t *index, const ulint *offsets, ulint n)
	Returns nonzero if the extern bit is set in nth field of rec. More...
void	rec_offs_make_nth_extern (dict_index_t *index, ulint *offsets, ulint n)
	Mark the nth field as externally stored. More...
ulint	rec_offs_nth_sql_null (const dict_index_t *index, const ulint *offsets, ulint n)
	Returns nonzero if the SQL NULL bit is set in nth field of rec. More...
ulint	rec_offs_nth_default (const dict_index_t *index, const ulint *offsets, ulint n)
	Returns nonzero if the default bit is set in nth field of rec. More...
ulint	rec_offs_nth_size (const dict_index_t *index, const ulint *offsets, ulint n)
	Gets the physical size of a field. More...
void	rec_set_nth_field (const dict_index_t *index, rec_t *rec, const ulint *offsets, ulint n, const void *data, ulint len)
	This is used to modify the value of an already existing field in a record. More...
ulint	rec_2_is_field_extern (const dict_index_t *index, const rec_t *rec, ulint n)
	Returns nonzero if the field is stored off-page. More...
ulint	rec_get_data_size_old (const rec_t *rec)
	The following function returns the data size of an old-style physical record, that is the sum of field lengths. More...

Detailed Description

Record manager wrapper declaration.

Record manager wrapper implementation.

After INSTANT ADD/DROP feature, fields index on logical record might not be same as field index on physical record. So this wrapper is implemented which translates logical index to physical index. And then functions of low level record manager (rem0lrec.h) are called with physical index of the field.

Created 13/08/2021 Mayank Prasad

Created 13/08/2021 Mayank Prasad

Function Documentation

rec_2_is_field_extern()

ulint rec_2_is_field_extern	(	const dict_index_t *	index,
		const rec_t *	rec,
		ulint	n
	)

Returns nonzero if the field is stored off-page.

Parameters

[in]	index	index
[in]	rec	record
[in]	n	field index

Return values

0	if the field is stored in-page
REC_2BYTE_EXTERN_MASK	if the field is stored externally

rec_get_data_size_old()

ulint rec_get_data_size_old

(

const rec_t *

rec

)

The following function returns the data size of an old-style physical record, that is the sum of field lengths.

SQL null fields are counted as length 0 fields. The value returned by the function is the distance from record origin to record end in bytes.

Returns

size

rec_get_nth_field()

byte * rec_get_nth_field	(	const dict_index_t *	index,
		const rec_t *	rec,
		const ulint *	offsets,
		ulint	n,
		ulint *	len
	)

Gets the value of the specified field in the record.

Parameters

[in]	index	record descriptor
[in]	rec	physical record
[in]	offsets	array returned by rec_get_offsets()
[in]	n	index of the field
[out]	len	length of the field, UNIV_SQL_NULL if SQL null

Returns

value of the field

rec_get_nth_field_offs()

ulint rec_get_nth_field_offs	(	const dict_index_t *	index,
		const ulint *	offsets,
		ulint	n,
		ulint *	len
	)

The following function is used to get an offset to the nth data field in a record.

Parameters

[in]	index	record descriptor
[in]	offsets	array returned by rec_get_offsets()
[in]	n	index of the field
[out]	len	length of the field; UNIV_SQL_NULL if SQL null; UNIV_SQL_ADD_COL_DEFAULT if it's default value and no value inlined

Returns

offset from the origin of rec

rec_get_nth_field_offs_old()

ulint rec_get_nth_field_offs_old	(	const dict_index_t *	index,
		const rec_t *	rec,
		ulint	n,
		ulint *	len
	)

The following function is used to get the offset to the nth data field in an old-style record.

Parameters

[in]	index	record descriptor
[in]	rec	record
[in]	n	index of the field
[in]	len	length of the field;UNIV_SQL_NULL if SQL null

Returns

offset to the field

rec_get_nth_field_old()

const byte * rec_get_nth_field_old	(	const dict_index_t *	index,
		const rec_t *	rec,
		ulint	n,
		ulint *	len
	)

rec_get_nth_field_size()

ulint rec_get_nth_field_size	(	const dict_index_t *	index,
		const rec_t *	rec,
		ulint	n
	)

Gets the physical size of an old-style field.

Also an SQL null may have a field of size > 0, if the data type is of a fixed size.

Parameters

[in]	index	record descriptor
[in]	rec	record
[in]	n	index of the field

Returns

field size in bytes

rec_offs_make_nth_extern()

void rec_offs_make_nth_extern	(	dict_index_t *	index,
		ulint *	offsets,
		ulint	n
	)

Mark the nth field as externally stored.

Parameters

[in]	index	record descriptor
[in]	offsets	array returned by rec_get_offsets()
[in]	n	nth field

rec_offs_nth_default()

ulint rec_offs_nth_default	(	const dict_index_t *	index,
		const ulint *	offsets,
		ulint	n
	)

Returns nonzero if the default bit is set in nth field of rec.

Parameters

[in]	index	record descriptor
[in]	offsets	array returned by rec_get_offsets()
[in]	n	nth field

Returns

nonzero if default bit is set

rec_offs_nth_extern()

ulint rec_offs_nth_extern	(	const dict_index_t *	index,
		const ulint *	offsets,
		ulint	n
	)

Returns nonzero if the extern bit is set in nth field of rec.

Parameters

[in]	index	record descriptor
[in]	offsets	array returned by rec_get_offsets()
[in]	n	nth field

Returns

nonzero if externally stored

rec_offs_nth_size()

ulint rec_offs_nth_size	(	const dict_index_t *	index,
		const ulint *	offsets,
		ulint	n
	)

Gets the physical size of a field.

Parameters

[in]	index	record descriptor
[in]	offsets	array returned by rec_get_offsets()
[in]	n	nth field

Returns

length of field

rec_offs_nth_sql_null()

ulint rec_offs_nth_sql_null	(	const dict_index_t *	index,
		const ulint *	offsets,
		ulint	n
	)

Returns nonzero if the SQL NULL bit is set in nth field of rec.

Parameters

[in]	index	record descriptor
[in]	offsets	array returned by rec_get_offsets()
[in]	n	nth field

Returns

nonzero if SQL NULL

rec_set_nth_field()

void rec_set_nth_field	(	const dict_index_t *	index,
		rec_t *	rec,
		const ulint *	offsets,
		ulint	n,
		const void *	data,
		ulint	len
	)

This is used to modify the value of an already existing field in a record.

The previous value must have exactly the same size as the new value. If len is UNIV_SQL_NULL then the field is treated as an SQL null. For records in ROW_FORMAT=COMPACT (new-style records), len must not be UNIV_SQL_NULL unless the field already is SQL null.

Parameters

[in]	index	record descriptor
[in]	rec	record
[in]	offsets	array returned by rec_get_offsets()
[in]	n	index number of the field
[in]	len	length of the data or UNIV_SQL_NULL. If not SQL null, must have the same length as the previous value. If SQL null, previous value must be SQL null.
[in]	data	pointer to the data if not SQL null