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

Copyright (c) 1996, 2009, Innobase Oy. 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/trx0trx.ic
The transaction

Created 3/26/1996 Heikki Tuuri
*******************************************************/

/********************************************************************//**
In XtraDB it is impossible for a transaction to own a search latch outside of
InnoDB code, so there is nothing to release on demand.  We keep this function to
simplify maintenance.*/
UNIV_INLINE
void
trx_search_latch_release_if_reserved(
/*=================================*/
	trx_t*	   trx __attribute__((unused))) /*!< in: transaction */
{
	ut_ad(!trx->has_search_latch);
}

/*************************************************************//**
Starts the transaction if it is not yet started. */
UNIV_INLINE
void
trx_start_if_not_started(
/*=====================*/
	trx_t*	trx)	/*!< in: transaction */
{
	ut_ad(trx->state != TRX_COMMITTED_IN_MEMORY);

	if (trx->state == TRX_NOT_STARTED) {

		trx_start(trx, ULINT_UNDEFINED);
	}
}

/*************************************************************//**
Starts the transaction if it is not yet started. Assumes we have reserved
the kernel mutex! */
UNIV_INLINE
void
trx_start_if_not_started_low(
/*=========================*/
	trx_t*	trx)	/*!< in: transaction */
{
	ut_ad(trx->state != TRX_COMMITTED_IN_MEMORY);

	if (trx->state == TRX_NOT_STARTED) {

		trx_start_low(trx, ULINT_UNDEFINED);
	}
}

/****************************************************************//**
Retrieves the error_info field from a trx.
@return	the error info */
UNIV_INLINE
const dict_index_t*
trx_get_error_info(
/*===============*/
	const trx_t*	trx)	/*!< in: trx object */
{
	return(trx->error_info);
}

/*******************************************************************//**
Retrieves transaction's que state in a human readable string. The string
should not be free()'d or modified.
@return	string in the data segment */
UNIV_INLINE
const char*
trx_get_que_state_str(
/*==================*/
	const trx_t*	trx)	/*!< in: transaction */
{
	/* be sure to adjust TRX_QUE_STATE_STR_MAX_LEN if you change this */
	switch (trx->que_state) {
	case TRX_QUE_RUNNING:
		return("RUNNING");
	case TRX_QUE_LOCK_WAIT:
		return("LOCK WAIT");
	case TRX_QUE_ROLLING_BACK:
		return("ROLLING BACK");
	case TRX_QUE_COMMITTING:
		return("COMMITTING");
	default:
		return("UNKNOWN");
	}
}

/**********************************************************************//**
Determine if a transaction is a dictionary operation.
@return	dictionary operation mode */
UNIV_INLINE
enum trx_dict_op
trx_get_dict_operation(
/*===================*/
	const trx_t*	trx)	/*!< in: transaction */
{
	enum trx_dict_op op = (enum trx_dict_op) trx->dict_operation;

#ifdef UNIV_DEBUG
	switch (op) {
	case TRX_DICT_OP_NONE:
	case TRX_DICT_OP_TABLE:
	case TRX_DICT_OP_INDEX:
		return(op);
	}
	ut_error;
#endif /* UNIV_DEBUG */
	return((enum trx_dict_op) UNIV_EXPECT(op, TRX_DICT_OP_NONE));
}
/**********************************************************************//**
Flag a transaction a dictionary operation. */
UNIV_INLINE
void
trx_set_dict_operation(
/*===================*/
	trx_t*			trx,	/*!< in/out: transaction */
	enum trx_dict_op	op)	/*!< in: operation, not
					TRX_DICT_OP_NONE */
{
#ifdef UNIV_DEBUG
	enum trx_dict_op	old_op = trx_get_dict_operation(trx);

	switch (op) {
	case TRX_DICT_OP_NONE:
		ut_error;
		break;
	case TRX_DICT_OP_TABLE:
		switch (old_op) {
		case TRX_DICT_OP_NONE:
		case TRX_DICT_OP_INDEX:
		case TRX_DICT_OP_TABLE:
			goto ok;
		}
		ut_error;
		break;
	case TRX_DICT_OP_INDEX:
		ut_ad(old_op == TRX_DICT_OP_NONE);
		break;
	}
ok:
#endif /* UNIV_DEBUG */

	trx->dict_operation = op;
}