~drizzle-trunk/drizzle/development

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

Query graph

(c) 1996 Innobase Oy

Created 5/27/1996 Heikki Tuuri

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

#include "usr0sess.h"

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

Gets the trx of a query thread. */

UNIV_INLINE

trx_t*

thr_get_trx(

/*========*/

	que_thr_t*	thr)	/* in: query thread */

{

	ut_ad(thr);

	return(thr->graph->trx);

}

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

Gets the first thr in a fork. */

UNIV_INLINE

que_thr_t*

que_fork_get_first_thr(

/*===================*/

	que_fork_t*	fork)	/* in: query fork */

{

	return(UT_LIST_GET_FIRST(fork->thrs));

}

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

Gets the child node of the first thr in a fork. */

UNIV_INLINE

que_node_t*

que_fork_get_child(

/*===============*/

	que_fork_t*	fork)	/* in: query fork */

{

	que_thr_t*	thr;

	thr = UT_LIST_GET_FIRST(fork->thrs);

	return(thr->child);

}

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

Gets the type of a graph node. */

UNIV_INLINE

ulint

que_node_get_type(

/*==============*/

	que_node_t*	node)	/* in: graph node */

{

	ut_ad(node);

	return(((que_common_t*)node)->type);

}

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

Gets pointer to the value dfield of a graph node. */

UNIV_INLINE

dfield_t*

que_node_get_val(

/*=============*/

	que_node_t*	node)	/* in: graph node */

{

	ut_ad(node);

	return(&(((que_common_t*)node)->val));

}

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

Gets the value buffer size of a graph node. */

UNIV_INLINE

ulint

que_node_get_val_buf_size(

/*======================*/

				/* out: val buffer size, not defined if

				val.data == NULL in node */

	que_node_t*	node)	/* in: graph node */

{

	ut_ad(node);

	return(((que_common_t*)node)->val_buf_size);

}

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

Sets the value buffer size of a graph node. */

UNIV_INLINE

void

que_node_set_val_buf_size(

/*======================*/

	que_node_t*	node,	/* in: graph node */

	ulint		size)	/* in: size */

{

	ut_ad(node);

	((que_common_t*)node)->val_buf_size = size;

}

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

Sets the parent of a graph node. */

UNIV_INLINE

void

que_node_set_parent(

/*================*/

	que_node_t*	node,	/* in: graph node */

	que_node_t*	parent)	/* in: parent */

{

	ut_ad(node);

	((que_common_t*)node)->parent = parent;

}

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

Gets pointer to the value data type field of a graph node. */

UNIV_INLINE

dtype_t*

que_node_get_data_type(

/*===================*/

	que_node_t*	node)	/* in: graph node */

{

	ut_ad(node);

	return(&(((que_common_t*)node)->val.type));

}

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

Catenates a query graph node to a list of them, possible empty list. */

UNIV_INLINE

que_node_t*

que_node_list_add_last(

/*===================*/

					/* out: one-way list of nodes */

	que_node_t*	node_list,	/* in: node list, or NULL */

	que_node_t*	node)		/* in: node */

{

	que_common_t*	cnode;

	que_common_t*	cnode2;

	cnode = node;

	cnode->brother = NULL;

	if (node_list == NULL) {

		return(node);

	}

	cnode2 = node_list;

	while (cnode2->brother != NULL) {

		cnode2 = cnode2->brother;

	}

	cnode2->brother = node;

	return(node_list);

}

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

Gets the next list node in a list of query graph nodes. */

UNIV_INLINE

que_node_t*

que_node_get_next(

/*==============*/

				/* out: next node in a list of nodes */

	que_node_t*	node)	/* in: node in a list */

{

	return(((que_common_t*)node)->brother);

}

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

Gets a query graph node list length. */

UNIV_INLINE

ulint

que_node_list_get_len(

/*==================*/

					/* out: length, for NULL list 0 */

	que_node_t*	node_list)	/* in: node list, or NULL */

{

	que_common_t*	cnode;

	ulint		len;

	cnode = node_list;

	len = 0;

	while (cnode != NULL) {

		len++;

		cnode = cnode->brother;

	}

	return(len);

}

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

Gets the parent node of a query graph node. */

UNIV_INLINE

que_node_t*

que_node_get_parent(

/*================*/

				/* out: parent node or NULL */

	que_node_t*	node)	/* in: node */

{

	return(((que_common_t*)node)->parent);

}

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

Checks if graph, trx, or session is in a state where the query thread should

be stopped. */

UNIV_INLINE

ibool

que_thr_peek_stop(

/*==============*/

				/* out: TRUE if should be stopped; NOTE that

				if the peek is made without reserving the

				kernel mutex, then another peek with the

				mutex reserved is necessary before deciding

				the actual stopping */

	que_thr_t*	thr)	/* in: query thread */

{

	trx_t*	trx;

	que_t*	graph;

	graph = thr->graph;

	trx = graph->trx;

	if (graph->state != QUE_FORK_ACTIVE

	    || trx->que_state == TRX_QUE_LOCK_WAIT

	    || (UT_LIST_GET_LEN(trx->signals) > 0

		&& trx->que_state == TRX_QUE_RUNNING)) {

		return(TRUE);

	}

	return(FALSE);

}

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

Returns TRUE if the query graph is for a SELECT statement. */

UNIV_INLINE

ibool

que_graph_is_select(

/*================*/

					/* out: TRUE if a select */

	que_t*		graph)		/* in: graph */

{

	if (graph->fork_type == QUE_FORK_SELECT_SCROLL

	    || graph->fork_type == QUE_FORK_SELECT_NON_SCROLL) {

		return(TRUE);

	}

	return(FALSE);

}