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

Copyright (c) 1996, 2011, Oracle and/or its affiliates. All Rights Reserved.

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
Foundation; version 2 of the License.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 
51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

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

/**************************************************//**
@file include/row0upd.ic
Update of a row

Created 12/27/1996 Heikki Tuuri
*******************************************************/

#include "mtr0log.h"
#ifndef UNIV_HOTBACKUP
# include "trx0trx.h"
# include "trx0undo.h"
# include "row0row.h"
# include "lock0lock.h"
#endif /* !UNIV_HOTBACKUP */
#include "page0zip.h"

/*********************************************************************//**
Creates an update vector object.
@return	own: update vector object */
UNIV_INLINE
upd_t*
upd_create(
/*=======*/
	ulint		n,	/*!< in: number of fields */
	mem_heap_t*	heap)	/*!< in: heap from which memory allocated */
{
	upd_t*	update;

	update = (upd_t*) mem_heap_alloc(heap, sizeof(upd_t));

	update->info_bits = 0;
	update->n_fields = n;
	update->fields = (upd_field_t*)
		mem_heap_alloc(heap, sizeof(upd_field_t) * n);

	return(update);
}

/*********************************************************************//**
Returns the number of fields in the update vector == number of columns
to be updated by an update vector.
@return	number of fields */
UNIV_INLINE
ulint
upd_get_n_fields(
/*=============*/
	const upd_t*	update)	/*!< in: update vector */
{
	ut_ad(update);

	return(update->n_fields);
}

#ifdef UNIV_DEBUG
/*********************************************************************//**
Returns the nth field of an update vector.
@return	update vector field */
UNIV_INLINE
upd_field_t*
upd_get_nth_field(
/*==============*/
	const upd_t*	update,	/*!< in: update vector */
	ulint		n)	/*!< in: field position in update vector */
{
	ut_ad(update);
	ut_ad(n < update->n_fields);

	return((upd_field_t*) update->fields + n);
}
#endif /* UNIV_DEBUG */

#ifndef UNIV_HOTBACKUP
/*********************************************************************//**
Sets an index field number to be updated by an update vector field. */
UNIV_INLINE
void
upd_field_set_field_no(
/*===================*/
	upd_field_t*	upd_field,	/*!< in: update vector field */
	ulint		field_no,	/*!< in: field number in a clustered
					index */
	dict_index_t*	index,		/*!< in: index */
	trx_t*		trx)		/*!< in: transaction */
{
	upd_field->field_no = field_no;
	upd_field->orig_len = 0;

	if (UNIV_UNLIKELY(field_no >= dict_index_get_n_fields(index))) {
		fprintf(stderr,
			"InnoDB: Error: trying to access field %lu in ",
			(ulong) field_no);
		dict_index_name_print(stderr, trx, index);
		fprintf(stderr, "\n"
			"InnoDB: but index only has %lu fields\n",
			(ulong) dict_index_get_n_fields(index));
	}

	dict_col_copy_type(dict_index_get_nth_col(index, field_no),
			   dfield_get_type(&upd_field->new_val));
}

/*********************************************************************//**
Returns a field of an update vector by field_no.
@return	update vector field, or NULL */
UNIV_INLINE
const upd_field_t*
upd_get_field_by_field_no(
/*======================*/
	const upd_t*	update,	/*!< in: update vector */
	ulint		no)	/*!< in: field_no */
{
	ulint	i;
	for (i = 0; i < upd_get_n_fields(update); i++) {
		const upd_field_t*	uf = upd_get_nth_field(update, i);

		if (uf->field_no == no) {

			return(uf);
		}
	}

	return(NULL);
}

/*********************************************************************//**
Updates the trx id and roll ptr field in a clustered index record when
a row is updated or marked deleted. */
UNIV_INLINE
void
row_upd_rec_sys_fields(
/*===================*/
	rec_t*		rec,	/*!< in/out: record */
	page_zip_des_t*	page_zip,/*!< in/out: compressed page whose
				uncompressed part will be updated, or NULL */
	dict_index_t*	index,	/*!< in: clustered index */
	const ulint*	offsets,/*!< in: rec_get_offsets(rec, index) */
	trx_t*		trx,	/*!< in: transaction */
	roll_ptr_t	roll_ptr)/*!< in: roll ptr of the undo log record */
{
	ut_ad(dict_index_is_clust(index));
	ut_ad(rec_offs_validate(rec, index, offsets));

	if (UNIV_LIKELY_NULL(page_zip)) {
		ulint	pos = dict_index_get_sys_col_pos(index, DATA_TRX_ID);
		page_zip_write_trx_id_and_roll_ptr(page_zip, rec, offsets,
						   pos, trx->id, roll_ptr);
	} else {
		ulint	offset = index->trx_id_offset;

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

#if DATA_TRX_ID + 1 != DATA_ROLL_PTR
# error "DATA_TRX_ID + 1 != DATA_ROLL_PTR"
#endif
		ut_ad(lock_check_trx_id_sanity(trx_read_trx_id(rec + offset),
					       rec, index, offsets, FALSE));
		trx_write_trx_id(rec + offset, trx->id);
		trx_write_roll_ptr(rec + offset + DATA_TRX_ID_LEN, roll_ptr);
	}
}
#endif /* !UNIV_HOTBACKUP */