equalfuncs.c

关系型数据库 Postgresql 6.5.2

		return false;
	if (!equal(a->inner, b->inner))
		return false;
	return true;
}

static bool
_equalMergeOrder(MergeOrder *a, MergeOrder *b)
{
	if (a == (MergeOrder *) NULL && b == (MergeOrder *) NULL)
		return true;
	Assert(IsA(a, MergeOrder));
	Assert(IsA(b, MergeOrder));

	if (a->join_operator != b->join_operator)
		return false;
	if (a->left_operator != b->left_operator)
		return false;
	if (a->right_operator != b->right_operator)
		return false;
	if (a->left_type != b->left_type)
		return false;
	if (a->right_type != b->right_type)
		return false;
	return true;
}

static bool
_equalHashInfo(HashInfo *a, HashInfo *b)
{
	Assert(IsA(a, HashInfo));
	Assert(IsA(b, HashInfo));

	if (a->hashop != b->hashop)
		return false;
	return true;
}

/* XXX	This equality function is a quick hack, should be
 *		fixed to compare all fields.
 */
static bool
_equalIndexScan(IndexScan *a, IndexScan *b)
{
	Assert(IsA(a, IndexScan));
	Assert(IsA(b, IndexScan));

	/*
	 * if(a->scan.plan.cost != b->scan.plan.cost) return(false);
	 */

	if (!equal(a->indxqual, b->indxqual))
		return false;

	if (a->scan.scanrelid != b->scan.scanrelid)
		return false;

	if (!equali(a->indxid, b->indxid))
		return false;
	return true;
}

static bool
_equalSubPlan(SubPlan *a, SubPlan *b)
{
	if (a->plan_id != b->plan_id)
		return false;

	if (!equal(a->sublink->oper, b->sublink->oper))
		return false;

	return true;
}

static bool
_equalJoinInfo(JoinInfo *a, JoinInfo *b)
{
	Assert(IsA(a, JoinInfo));
	Assert(IsA(b, JoinInfo));
	if (!equal(a->unjoined_relids, b->unjoined_relids))
		return false;
	if (!equal(a->jinfo_restrictinfo, b->jinfo_restrictinfo))
		return false;
	if (a->mergejoinable != b->mergejoinable)
		return false;
	if (a->hashjoinable != b->hashjoinable)
		return false;
	return true;
}

/*
 *	Stuff from execnodes.h
 */

/*
 *	EState is a subclass of Node.
 */
static bool
_equalEState(EState *a, EState *b)
{
	if (a->es_direction != b->es_direction)
		return false;

	if (!equal(a->es_range_table, b->es_range_table))
		return false;

	if (a->es_result_relation_info != b->es_result_relation_info)
		return false;

	return true;
}

/*
 * Stuff from parsenodes.h
 */

static bool
_equalQuery(Query *a, Query *b)
{
	if (a->commandType != b->commandType)
		return false;
	if (!equal(a->utilityStmt, b->utilityStmt))
		return false;
	if (a->resultRelation != b->resultRelation)
		return false;
	if (a->into && b->into)
	{
		if (strcmp(a->into, b->into) != 0)
			return false;
	}
	else
	{
		if (a->into != b->into)
			return false;
	}
	if (a->isPortal != b->isPortal)
		return false;
	if (a->isBinary != b->isBinary)
		return false;
	if (a->isTemp != b->isTemp)
		return false;
	if (a->unionall != b->unionall)
		return false;
	if (a->hasAggs != b->hasAggs)
		return false;
	if (a->hasSubLinks != b->hasSubLinks)
		return false;
	if (a->uniqueFlag && b->uniqueFlag)
	{
		if (strcmp(a->uniqueFlag, b->uniqueFlag) != 0)
			return false;
	}
	else
	{
		if (a->uniqueFlag != b->uniqueFlag)
			return false;
	}
	if (!equal(a->sortClause, b->sortClause))
		return false;
	if (!equal(a->rtable, b->rtable))
		return false;
	if (!equal(a->targetList, b->targetList))
		return false;
	if (!equal(a->qual, b->qual))
		return false;
	if (!equal(a->rowMark, b->rowMark))
		return false;
	if (!equal(a->groupClause, b->groupClause))
		return false;
	if (!equal(a->havingQual, b->havingQual))
		return false;
	if (!equal(a->intersectClause, b->intersectClause))
		return false;
	if (!equal(a->unionClause, b->unionClause))
		return false;
	if (!equal(a->limitOffset, b->limitOffset))
		return false;
	if (!equal(a->limitCount, b->limitCount))
		return false;

	/*
	 * We do not check the internal-to-the-planner fields base_rel_list
	 * and join_rel_list.  They might not be set yet, and in any case they
	 * should be derivable from the other fields.
	 */
	return true;
}

static bool
_equalRangeTblEntry(RangeTblEntry *a, RangeTblEntry *b)
{
	if (a->relname && b->relname)
	{
		if (strcmp(a->relname, b->relname) != 0)
			return false;
	}
	else
	{
		if (a->relname != b->relname)
			return false;
	}
	if (a->refname && b->refname)
	{
		if (strcmp(a->refname, b->refname) != 0)
			return false;
	}
	else
	{
		if (a->refname != b->refname)
			return false;
	}
	if (a->relid != b->relid)
		return false;
	if (a->inh != b->inh)
		return false;
	if (a->inFromCl != b->inFromCl)
		return false;
	if (a->skipAcl != b->skipAcl)
		return false;

	return true;
}

static bool
_equalTargetEntry(TargetEntry *a, TargetEntry *b)
{
	if (!equal(a->resdom, b->resdom))
		return false;
	if (!equal(a->fjoin, b->fjoin))
		return false;
	if (!equal(a->expr, b->expr))
		return false;

	return true;
}

static bool
_equalCaseExpr(CaseExpr *a, CaseExpr *b)
{
	if (a->casetype != b->casetype)
		return false;
	if (!equal(a->arg, b->arg))
		return false;
	if (!equal(a->args, b->args))
		return false;
	if (!equal(a->defresult, b->defresult))
		return false;

	return true;
}

static bool
_equalCaseWhen(CaseWhen *a, CaseWhen *b)
{
	if (!equal(a->expr, b->expr))
		return false;
	if (!equal(a->result, b->result))
		return false;

	return true;
}

/*
 * Stuff from pg_list.h
 */

static bool
_equalValue(Value *a, Value *b)
{
	if (a->type != b->type)
		return false;

	switch (a->type)
	{
		case T_String:
			return strcmp(a->val.str, b->val.str);
		case T_Integer:
			return a->val.ival == b->val.ival;
		case T_Float:
			return a->val.dval == b->val.dval;
		default:
			break;
	}

	return true;
}

/*
 * equal
 *	  returns whether two nodes are equal
 */
bool
equal(void *a, void *b)
{
	bool		retval = false;

	if (a == b)
		return true;

	/*
	 * note that a!=b, so only one of them can be NULL
	 */
	if (a == NULL || b == NULL)
		return false;

	/*
	 * are they the same type of nodes?
	 */
	if (nodeTag(a) != nodeTag(b))
		return false;

	switch (nodeTag(a))
	{
		case T_Resdom:
			retval = _equalResdom(a, b);
			break;
		case T_Fjoin:
			retval = _equalFjoin(a, b);
			break;
		case T_Expr:
			retval = _equalExpr(a, b);
			break;
		case T_Iter:
			retval = _equalIter(a, b);
			break;
		case T_Stream:
			retval = _equalStream(a, b);
			break;
		case T_Var:
			retval = _equalVar(a, b);
			break;
		case T_Array:
			retval = _equalArray(a, b);
			break;
		case T_ArrayRef:
			retval = _equalArrayRef(a, b);
			break;
		case T_Oper:
			retval = _equalOper(a, b);
			break;
		case T_Const:
			retval = _equalConst(a, b);
			break;
		case T_Param:
			retval = _equalParam(a, b);
			break;
		case T_Aggref:
			retval = _equalAggref(a, b);
			break;
		case T_Func:
			retval = _equalFunc(a, b);
			break;
		case T_RestrictInfo:
			retval = _equalRestrictInfo(a, b);
			break;
		case T_RelOptInfo:
			retval = _equalRelOptInfo(a, b);
			break;
		case T_JoinMethod:
			retval = _equalJoinMethod(a, b);
			break;
		case T_Path:
			retval = _equalPath(a, b);
			break;
		case T_IndexPath:
			retval = _equalIndexPath(a, b);
			break;
		case T_NestPath:
			retval = _equalNestPath(a, b);
			break;
		case T_MergePath:
			retval = _equalMergePath(a, b);
			break;
		case T_HashPath:
			retval = _equalHashPath(a, b);
			break;
		case T_JoinKey:
			retval = _equalJoinKey(a, b);
			break;
		case T_MergeOrder:
			retval = _equalMergeOrder(a, b);
			break;
		case T_HashInfo:
			retval = _equalHashInfo(a, b);
			break;
		case T_IndexScan:
			retval = _equalIndexScan(a, b);
			break;
		case T_SubPlan:
			retval = _equalSubPlan(a, b);
			break;
		case T_JoinInfo:
			retval = _equalJoinInfo(a, b);
			break;
		case T_EState:
			retval = _equalEState(a, b);
			break;
		case T_Integer:
		case T_String:
		case T_Float:
			retval = _equalValue(a, b);
			break;
		case T_List:
			{
				List	   *la = (List *) a;
				List	   *lb = (List *) b;
				List	   *l;

				if (a == NULL && b == NULL)
					return true;
				if (length(a) != length(b))
					return false;
				foreach(l, la)
				{
					if (!equal(lfirst(l), lfirst(lb)))
						return false;
					lb = lnext(lb);
				}
				retval = true;
			}
			break;
		case T_Query:
			retval = _equalQuery(a, b);
			break;
		case T_RangeTblEntry:
			retval = _equalRangeTblEntry(a, b);
			break;
		case T_TargetEntry:
			retval = _equalTargetEntry(a, b);
			break;
		case T_CaseExpr:
			retval = _equalCaseExpr(a, b);
			break;
		case T_CaseWhen:
			retval = _equalCaseWhen(a, b);
			break;
		default:
			elog(NOTICE, "equal: don't know whether nodes of type %d are equal",
				 nodeTag(a));
			break;
	}

	return retval;
}

/*
 * equali
 *	  compares two lists of integers
 *
 * XXX temp hack. needs something like T_IntList
 */
static bool
equali(List *a, List *b)
{
	List	   *la = (List *) a;
	List	   *lb = (List *) b;
	List	   *l;

	if (a == NULL && b == NULL)
		return true;
	if (length(a) != length(b))
		return false;
	foreach(l, la)
	{
		if (lfirsti(l) != lfirsti(lb))
			return false;
		lb = lnext(lb);
	}
	return true;
}