/*****************************************************************************

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Copyright (c) 2017, 2018, MariaDB Corporation.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

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this program; if not, write to the Free Software Foundation, Inc.,
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*****************************************************************************/

/**************************************************//**
@file include/row0row.ic
General row routines

Created 4/20/1996 Heikki Tuuri
*******************************************************/

#include "dict0dict.h"
#include "rem0rec.h"
#include "trx0undo.h"

/*********************************************************************//**
Gets the offset of the DB_TRX_ID field, in bytes relative to the origin of
a clustered index record.
@return offset of DATA_TRX_ID */
UNIV_INLINE
ulint
row_get_trx_id_offset(
/*==================*/
	const dict_index_t*	index,	/*!< in: clustered index */
	const rec_offs*		offsets)/*!< in: record offsets */
{
	ulint	offset;
	ulint	len;

	ut_ad(rec_offs_validate(NULL, index, offsets));

	offset = rec_get_nth_field_offs(offsets, index->db_trx_id(), &len);

	ut_ad(len == DATA_TRX_ID_LEN);

	return(offset);
}

/*********************************************************************//**
Reads the trx id field from a clustered index record.
@return value of the field */
UNIV_INLINE
trx_id_t
row_get_rec_trx_id(
/*===============*/
	const rec_t*		rec,	/*!< in: record */
	const dict_index_t*	index,	/*!< in: clustered index */
	const rec_offs*		offsets)/*!< in: rec_get_offsets(rec, index) */
{
	ulint	offset;

	ut_ad(dict_index_is_clust(index));
	ut_ad(rec_offs_validate(rec, index, offsets));

	offset = index->trx_id_offset;

	if (!offset) {
		offset = row_get_trx_id_offset(index, offsets);
	}

	return(trx_read_trx_id(rec + offset));
}

/*********************************************************************//**
Reads the roll pointer field from a clustered index record.
@return value of the field */
UNIV_INLINE
roll_ptr_t
row_get_rec_roll_ptr(
/*=================*/
	const rec_t*		rec,	/*!< in: record */
	const dict_index_t*	index,	/*!< in: clustered index */
	const rec_offs*		offsets)/*!< in: rec_get_offsets(rec, index) */
{
	ulint	offset;

	ut_ad(dict_index_is_clust(index));
	ut_ad(rec_offs_validate(rec, index, offsets));

	offset = index->trx_id_offset;

	if (!offset) {
		offset = row_get_trx_id_offset(index, offsets);
	}

	return(trx_read_roll_ptr(rec + offset + DATA_TRX_ID_LEN));
}

/*****************************************************************//**
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_INLINE
dtuple_t*
row_build_index_entry(
/*==================*/
	const dtuple_t*		row,	/*!< in: row which should be
					inserted or purged */
	const row_ext_t*	ext,	/*!< in: externally stored column
					prefixes, or NULL */
	const dict_index_t*	index,	/*!< in: index on the table */
	mem_heap_t*		heap)	/*!< in,out: memory heap from which
					the memory for the index entry
					is allocated */
{
	dtuple_t*	entry;

	ut_ad(dtuple_check_typed(row));
	entry = row_build_index_entry_low(row, ext, index, heap,
					  ROW_BUILD_NORMAL);
	ut_ad(!entry || dtuple_check_typed(entry));
	return(entry);
}

/*******************************************************************//**
Builds from a secondary index record a row reference with which we can
search the clustered index record. */
UNIV_INLINE
void
row_build_row_ref_fast(
/*===================*/
	dtuple_t*	ref,	/*!< in/out: typed data tuple where the
				reference is built */
	const ulint*	map,	/*!< in: array of field numbers in rec
				telling how ref should be built from
				the fields of rec */
	const rec_t*	rec,	/*!< in: secondary index record;
				must be preserved while ref is used, as we do
				not copy field values to heap */
	const rec_offs*	offsets)/*!< in: array returned by rec_get_offsets() */
{
	dfield_t*	dfield;
	const byte*	field;
	ulint		len;
	ulint		ref_len;
	ulint		field_no;
	ulint		i;

	ut_ad(rec_offs_validate(rec, NULL, offsets));
	ut_ad(!rec_offs_any_extern(offsets));
	ref_len = dtuple_get_n_fields(ref);

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

		field_no = *(map + i);

		if (field_no != ULINT_UNDEFINED) {

			field = rec_get_nth_field(rec, offsets,
						  field_no, &len);
			dfield_set_data(dfield, field, len);
		}
	}
}
