exectuples.c

关系型数据库 Postgresql 6.5.2

	slot->ttc_descIsNew = isNew;
}

/* --------------------------------
 *		ExecSetNewSlotDescriptor
 *
 *		This function is used to set the tuple descriptor associated
 *		with the slot's tuple, and set the "isNew" flag at the same time.
 * --------------------------------
 */
#ifdef NOT_USED
TupleDesc						/* return: old slot tuple descriptor */
ExecSetNewSlotDescriptor(TupleTableSlot *slot,	/* slot to change */
						 TupleDesc tupdesc)		/* tuple descriptor */
{
	TupleDesc	old_tupdesc = slot->ttc_tupleDescriptor;

	slot->ttc_tupleDescriptor = tupdesc;
	slot->ttc_descIsNew = true;

	return old_tupdesc;
}

#endif

/* --------------------------------
 *		ExecSlotBuffer
 *
 *		This function is used to get the tuple descriptor associated
 *		with the slot's tuple.  Be very careful with this as it does not
 *		balance the reference counts.  If the buffer returned is stored
 *		someplace else, then also use ExecIncrSlotBufferRefcnt().
 *
 * Now a macro in tuptable.h
 * --------------------------------
 */

/* --------------------------------
 *		ExecSetSlotBuffer
 *
 *		This function is used to set the tuple descriptor associated
 *		with the slot's tuple.   Be very careful with this as it does not
 *		balance the reference counts.  If we're using this then we should
 *		also use ExecIncrSlotBufferRefcnt().
 * --------------------------------
 */
#ifdef NOT_USED
Buffer							/* return: old slot buffer */
ExecSetSlotBuffer(TupleTableSlot *slot, /* slot to change */
				  Buffer b)		/* tuple descriptor */
{
	Buffer		oldb = slot->ttc_buffer;

	slot->ttc_buffer = b;

	return oldb;
}

#endif

/* ----------------------------------------------------------------
 *				  tuple table slot status predicates
 * ----------------------------------------------------------------
 */

/* --------------------------------
 *		ExecSlotDescriptorIsNew
 *
 *		This function is used to check if the tuple descriptor
 *		associated with this slot has just changed.  ie: we are
 *		now storing a new type of tuple in this slot
 * --------------------------------
 */
#ifdef NOT_USED
bool							/* return: descriptor "is new" */
ExecSlotDescriptorIsNew(TupleTableSlot *slot)	/* slot to inspect */
{
/*	  bool isNew = SlotTupleDescriptorIsNew((TupleTableSlot*) slot);
	return isNew; */
	return slot->ttc_descIsNew;
}

#endif

/* ----------------------------------------------------------------
 *				convenience initialization routines
 * ----------------------------------------------------------------
 */
/* --------------------------------
 *		ExecInit{Result,Scan,Raw,Marked,Outer,Hash}TupleSlot
 *
 *		These are convenience routines to initialize the specfied slot
 *		in nodes inheriting the appropriate state.
 * --------------------------------
 */
#define INIT_SLOT_DEFS \
	TupleTable	   tupleTable; \
	TupleTableSlot*   slot

#define INIT_SLOT_ALLOC \
	tupleTable = (TupleTable) estate->es_tupleTable; \
	slot =		 ExecAllocTableSlot(tupleTable); \
	slot->val = (HeapTuple)NULL; \
	slot->ttc_shouldFree = true; \
	slot->ttc_tupleDescriptor = (TupleDesc)NULL; \
	slot->ttc_whichplan = -1;\
	slot->ttc_descIsNew = true;

/* ----------------
 *		ExecInitResultTupleSlot
 * ----------------
 */
void
ExecInitResultTupleSlot(EState *estate, CommonState *commonstate)
{
	INIT_SLOT_DEFS;
	INIT_SLOT_ALLOC;
	commonstate->cs_ResultTupleSlot = (TupleTableSlot *) slot;
}

/* ----------------
 *		ExecInitScanTupleSlot
 * ----------------
 */
void
ExecInitScanTupleSlot(EState *estate, CommonScanState *commonscanstate)
{
	INIT_SLOT_DEFS;
	INIT_SLOT_ALLOC;
	commonscanstate->css_ScanTupleSlot = (TupleTableSlot *) slot;
}

#ifdef NOT_USED
/* ----------------
 *		ExecInitMarkedTupleSlot
 * ----------------
 */
void
ExecInitMarkedTupleSlot(EState *estate, MergeJoinState *mergestate)
{
	INIT_SLOT_DEFS;
	INIT_SLOT_ALLOC;
	mergestate->mj_MarkedTupleSlot = (TupleTableSlot *) slot;
}

#endif

/* ----------------
 *		ExecInitOuterTupleSlot
 * ----------------
 */
void
ExecInitOuterTupleSlot(EState *estate, HashJoinState *hashstate)
{
	INIT_SLOT_DEFS;
	INIT_SLOT_ALLOC;
	hashstate->hj_OuterTupleSlot = slot;
}

/* ----------------
 *		ExecInitHashTupleSlot
 * ----------------
 */
#ifdef NOT_USED
void
ExecInitHashTupleSlot(EState *estate, HashJoinState *hashstate)
{
	INIT_SLOT_DEFS;
	INIT_SLOT_ALLOC;
	hashstate->hj_HashTupleSlot = slot;
}

#endif

static TupleTableSlot *
NodeGetResultTupleSlot(Plan *node)
{
	TupleTableSlot *slot;

	switch (nodeTag(node))
	{

		case T_Result:
			{
				ResultState *resstate = ((Result *) node)->resstate;

				slot = resstate->cstate.cs_ResultTupleSlot;
			}
			break;

		case T_SeqScan:
			{
				CommonScanState *scanstate = ((SeqScan *) node)->scanstate;

				slot = scanstate->cstate.cs_ResultTupleSlot;
			}
			break;

		case T_NestLoop:
			{
				NestLoopState *nlstate = ((NestLoop *) node)->nlstate;

				slot = nlstate->jstate.cs_ResultTupleSlot;
			}
			break;

		case T_Append:
			{
				Append	   *n = (Append *) node;
				AppendState *appendstate;
				List	   *appendplans;
				int			whichplan;
				Plan	   *subplan;

				appendstate = n->appendstate;
				appendplans = n->appendplans;
				whichplan = appendstate->as_whichplan;

				subplan = (Plan *) nth(whichplan, appendplans);
				slot = NodeGetResultTupleSlot(subplan);
				break;
			}

		case T_IndexScan:
			{
				CommonScanState *scanstate = ((IndexScan *) node)->scan.scanstate;

				slot = scanstate->cstate.cs_ResultTupleSlot;
			}
			break;

		case T_Material:
			{
				MaterialState *matstate = ((Material *) node)->matstate;

				slot = matstate->csstate.css_ScanTupleSlot;
			}
			break;

		case T_Sort:
			{
				SortState  *sortstate = ((Sort *) node)->sortstate;

				slot = sortstate->csstate.css_ScanTupleSlot;
			}
			break;

		case T_Agg:
			{
				AggState   *aggstate = ((Agg *) node)->aggstate;

				slot = aggstate->csstate.cstate.cs_ResultTupleSlot;
			}
			break;

		case T_Group:
			{
				GroupState *grpstate = ((Group *) node)->grpstate;

				slot = grpstate->csstate.cstate.cs_ResultTupleSlot;
			}
			break;

		case T_Hash:
			{
				HashState  *hashstate = ((Hash *) node)->hashstate;

				slot = hashstate->cstate.cs_ResultTupleSlot;
			}
			break;

		case T_Unique:
			{
				UniqueState *uniquestate = ((Unique *) node)->uniquestate;

				slot = uniquestate->cs_ResultTupleSlot;
			}
			break;

		case T_MergeJoin:
			{
				MergeJoinState *mergestate = ((MergeJoin *) node)->mergestate;

				slot = mergestate->jstate.cs_ResultTupleSlot;
			}
			break;

		case T_HashJoin:
			{
				HashJoinState *hashjoinstate = ((HashJoin *) node)->hashjoinstate;

				slot = hashjoinstate->jstate.cs_ResultTupleSlot;
			}
			break;

		default:
			/* ----------------
			 *	  should never get here
			 * ----------------
			 */
			elog(ERROR, "NodeGetResultTupleSlot: node not yet supported: %d ",
				 nodeTag(node));

			return NULL;
	}
	return slot;
}

/* ----------------------------------------------------------------
 *		ExecGetTupType
 *
 *		this gives you the tuple descriptor for tuples returned
 *		by this node.  I really wish I could ditch this routine,
 *		but since not all nodes store their type info in the same
 *		place, we have to do something special for each node type.
 *
 *		Soon, the system will have to adapt to deal with changing
 *		tuple descriptors as we deal with dynamic tuple types
 *		being returned from procedure nodes.  Perhaps then this
 *		routine can be retired.  -cim 6/3/91
 *
 * old comments
 *		This routine just gets the type information out of the
 *		node's state.  If you already have a node's state, you
 *		can get this information directly, but this is a useful
 *		routine if you want to get the type information from
 *		the node's inner or outer subplan easily without having
 *		to inspect the subplan.. -cim 10/16/89
 *
 * ----------------------------------------------------------------
 */

TupleDesc
ExecGetTupType(Plan *node)
{
	TupleTableSlot *slot;
	TupleDesc	tupType;

	if (node == NULL)
		return NULL;

	slot = NodeGetResultTupleSlot(node);
	tupType = slot->ttc_tupleDescriptor;
	return tupType;
}

/*
TupleDesc
ExecCopyTupType(TupleDesc td, int natts)
{
	TupleDesc newTd;
	int				i;

	newTd = CreateTemplateTupleDesc(natts);
	i = 0;
	while (i < natts)
		{
			newTd[i] = (Form_pg_attribute)palloc(sizeof(FormData_pg_attribute));
			memmove(newTd[i], td[i], sizeof(FormData_pg_attribute));
			i++;
		}
	return newTd;
}
*/

/* ----------------------------------------------------------------
 *		ExecTypeFromTL
 *
 *		Currently there are about 4 different places where we create
 *		TupleDescriptors.  They should all be merged, or perhaps
 *		be rewritten to call BuildDesc().
 *
 *	old comments
 *		Forms attribute type info from the target list in the node.
 *		It assumes all domains are individually specified in the target list.
 *		It fails if the target list contains something like Emp.all
 *		which represents all the attributes from EMP relation.
 *
 *		Conditions:
 *			The inner and outer subtrees should be initialized because it
 *			might be necessary to know the type infos of the subtrees.
 * ----------------------------------------------------------------
 */
TupleDesc
ExecTypeFromTL(List *targetList)
{
	List	   *tlcdr;
	TupleDesc	typeInfo;
	Resdom	   *resdom;
	Oid			restype;
	int			len;

	/* ----------------
	 *	examine targetlist - if empty then return NULL
	 * ----------------
	 */
	len = ExecTargetListLength(targetList);

	if (len == 0)
		return NULL;

	/* ----------------
	 *	allocate a new typeInfo
	 * ----------------
	 */
	typeInfo = CreateTemplateTupleDesc(len);

	/* ----------------
	 * notes: get resdom from (resdom expr)
	 *		  get_typbyval comes from src/lib/l-lisp/lsyscache.c
	 * ----------------
	 */
	tlcdr = targetList;
	while (tlcdr != NIL)
	{
		TargetEntry *tle = lfirst(tlcdr);

		if (tle->resdom != NULL)
		{
			resdom = tle->resdom;
			restype = resdom->restype;

			TupleDescInitEntry(typeInfo,
							   resdom->resno,
							   resdom->resname,
			/* fix for SELECT NULL ... */
							   (restype ? restype : UNKNOWNOID),
							   resdom->restypmod,
							   0,
							   false);

/*
			ExecSetTypeInfo(resdom->resno - 1,
							typeInfo,
							(Oid) restype,
							resdom->resno,
							resdom->reslen,
							resdom->resname->data,
							get_typbyval(restype),
							get_typalign(restype));
*/
		}
		else
		{
			Resdom	   *fjRes;
			List	   *fjTlistP;
			List	   *fjList = lfirst(tlcdr);

#ifdef SETS_FIXED
			TargetEntry *tle;
			Fjoin	   *fjNode = ((TargetEntry *) lfirst(fjList))->fjoin;

			tle = fjNode->fj_innerNode; /* ??? */
#endif
			fjRes = tle->resdom;
			restype = fjRes->restype;

			TupleDescInitEntry(typeInfo,
							   fjRes->resno,
							   fjRes->resname,
							   restype,
							   fjRes->restypmod,
							   0,
							   false);
/*
			ExecSetTypeInfo(fjRes->resno - 1,
							typeInfo,
							(Oid) restype,
							fjRes->resno,
							fjRes->reslen,
							(char *) fjRes->resname,
							get_typbyval(restype),
							get_typalign(restype));
*/

			foreach(fjTlistP, lnext(fjList))
			{
				TargetEntry *fjTle = lfirst(fjTlistP);

				fjRes = fjTle->resdom;

				TupleDescInitEntry(typeInfo,
								   fjRes->resno,
								   fjRes->resname,
								   restype,
								   fjRes->restypmod,
								   0,
								   false);

/*
				ExecSetTypeInfo(fjRes->resno - 1,
								typeInfo,
								(Oid) fjRes->restype,
								fjRes->resno,
								fjRes->reslen,
								(char *) fjRes->resname,
								get_typbyval(fjRes->restype),
								get_typalign(fjRes->restype));
*/
			}
		}

		tlcdr = lnext(tlcdr);
	}

	return typeInfo;
}