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

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
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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.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA

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

/**************************************************//**
@file include/trx0trx.ic
The transaction

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

/**********************************************************************//**
Determines if a transaction is in the given state.
The caller must hold trx_sys->mutex, or it must be the thread
that is serving a running transaction.
A running transaction must be in trx_sys->ro_trx_list or trx_sys->rw_trx_list
unless it is a non-locking autocommit read only transaction, which is only
in trx_sys->mysql_trx_list.
@return	TRUE if trx->state == state */
UNIV_INLINE
ibool
trx_state_eq(
/*=========*/
	const trx_t*	trx,	/*!< in: transaction */
	trx_state_t	state)	/*!< in: state;
				if state != TRX_STATE_NOT_STARTED
				asserts that
				trx->state != TRX_STATE_NOT_STARTED */
{
#ifdef UNIV_DEBUG
	switch (trx->state) {
	case TRX_STATE_PREPARED:
		ut_ad(!trx_is_autocommit_non_locking(trx));
		return(trx->state == state);

	case TRX_STATE_ACTIVE:
		assert_trx_nonlocking_or_in_list(trx);
		return(state == trx->state);

	case TRX_STATE_COMMITTED_IN_MEMORY:
		assert_trx_in_list(trx);
		return(state == trx->state);

	case TRX_STATE_NOT_STARTED:
		/* This state is not allowed for running transactions. */
		ut_a(state == TRX_STATE_NOT_STARTED);
		ut_ad(!trx->in_rw_trx_list);
		ut_ad(!trx->in_ro_trx_list);
		return(state == trx->state);
	}
	ut_error;
#endif /* UNIV_DEBUG */
	return(trx->state == state);
}

/****************************************************************//**
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->lock.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_t
trx_get_dict_operation(
/*===================*/
	const trx_t*	trx)	/*!< in: transaction */
{
	trx_dict_op_t op = static_cast<trx_dict_op_t>(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(op);
}
/**********************************************************************//**
Flag a transaction a dictionary operation. */
UNIV_INLINE
void
trx_set_dict_operation(
/*===================*/
	trx_t*			trx,	/*!< in/out: transaction */
	enum trx_dict_op_t	op)	/*!< in: operation, not
					TRX_DICT_OP_NONE */
{
#ifdef UNIV_DEBUG
	enum trx_dict_op_t	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->ddl = true;
	trx->dict_operation = op;
}

/********************************************************************//**
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);
}