copyfuncs.c

关系型数据库 Postgresql 6.5.2

/* ----------------
 *		_copyExpr
 * ----------------
 */
static Expr *
_copyExpr(Expr *from)
{
	Expr	   *newnode = makeNode(Expr);

	/* ----------------
	 *	copy node superclass fields
	 * ----------------
	 */
	newnode->typeOid = from->typeOid;
	newnode->opType = from->opType;

	Node_Copy(from, newnode, oper);
	Node_Copy(from, newnode, args);

	return newnode;
}

/* ----------------
 *		_copyVar
 * ----------------
 */
static Var *
_copyVar(Var *from)
{
	Var		   *newnode = makeNode(Var);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->varno = from->varno;
	newnode->varattno = from->varattno;
	newnode->vartype = from->vartype;
	newnode->vartypmod = from->vartypmod;
	newnode->varlevelsup = from->varlevelsup;

	newnode->varnoold = from->varnoold;
	newnode->varoattno = from->varoattno;

	return newnode;
}

/* ----------------
 *		_copyOper
 * ----------------
 */
static Oper *
_copyOper(Oper *from)
{
	Oper	   *newnode = makeNode(Oper);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->opno = from->opno;
	newnode->opid = from->opid;
	newnode->opresulttype = from->opresulttype;
	newnode->opsize = from->opsize;

	/*
	 * NOTE: shall we copy the cache structure or just the pointer ?
	 * Alternatively we can set 'op_fcache' to NULL, in which case the
	 * executor will initialize it when it needs it...
	 */
	newnode->op_fcache = from->op_fcache;

	return newnode;
}

/* ----------------
 *		_copyConst
 * ----------------
 */
static Const *
_copyConst(Const *from)
{
	static Oid	cached_type;
	static bool cached_typbyval;

	Const	   *newnode = makeNode(Const);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->consttype = from->consttype;
	newnode->constlen = from->constlen;

	/* ----------------
	 *	XXX super cheesy hack until parser/planner
	 *	puts in the right values here.
	 *
	 *	But I like cheese.
	 * ----------------
	 */
	if (!from->constisnull && cached_type != from->consttype)
	{
		HeapTuple	typeTuple;
		Form_pg_type typeStruct;

		/* ----------------
		 *	 get the type tuple corresponding to the paramList->type,
		 *	 If this fails, returnValue has been pre-initialized
		 *	 to "null" so we just return it.
		 * ----------------
		 */
		typeTuple = SearchSysCacheTuple(TYPOID,
										ObjectIdGetDatum(from->consttype),
										0, 0, 0);

		/* ----------------
		 *	 get the type length and by-value from the type tuple and
		 *	 save the information in our one element cache.
		 * ----------------
		 */
		Assert(PointerIsValid(typeTuple));

		typeStruct = (Form_pg_type) GETSTRUCT(typeTuple);
		cached_typbyval = (typeStruct)->typbyval ? true : false;
		cached_type = from->consttype;
	}

	from->constbyval = cached_typbyval;

	if (!from->constisnull)
	{
		/* ----------------
		 *		copying the Datum in a const node is a bit trickier
		 *	because it might be a pointer and it might also be of
		 *	variable length...
		 * ----------------
		 */
		if (from->constbyval == true)
		{
			/* ----------------
			 *	passed by value so just copy the datum.
			 * ----------------
			 */
			newnode->constvalue = from->constvalue;
		}
		else
		{
			/* ----------------
			 *	not passed by value. datum contains a pointer.
			 * ----------------
			 */
			if (from->constlen != -1)
			{
				/* ----------------
				 *		fixed length structure
				 * ----------------
				 */
				newnode->constvalue = PointerGetDatum(palloc(from->constlen));
				memmove((char *) newnode->constvalue,
						(char *) from->constvalue, from->constlen);
			}
			else
			{
				/* ----------------
				 *		variable length structure.	here the length is stored
				 *	in the first int pointed to by the constval.
				 * ----------------
				 */
				int			length;

				length = VARSIZE(from->constvalue);
				newnode->constvalue = PointerGetDatum(palloc(length));
				memmove((char *) newnode->constvalue,
						(char *) from->constvalue, length);
			}
		}
	}
	else
		newnode->constvalue = from->constvalue;
	newnode->constisnull = from->constisnull;
	newnode->constbyval = from->constbyval;
	newnode->constisset = from->constisset;
	newnode->constiscast = from->constiscast;

	return newnode;
}

/* ----------------
 *		_copyParam
 * ----------------
 */
static Param *
_copyParam(Param *from)
{
	Param	   *newnode = makeNode(Param);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->paramkind = from->paramkind;
	newnode->paramid = from->paramid;

	if (from->paramname != NULL)
		newnode->paramname = pstrdup(from->paramname);
	newnode->paramtype = from->paramtype;
	Node_Copy(from, newnode, param_tlist);

	return newnode;
}

/* ----------------
 *		_copyFunc
 * ----------------
 */
static Func *
_copyFunc(Func *from)
{
	Func	   *newnode = makeNode(Func);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->funcid = from->funcid;
	newnode->functype = from->functype;
	newnode->funcisindex = from->funcisindex;
	newnode->funcsize = from->funcsize;
	newnode->func_fcache = from->func_fcache;
	Node_Copy(from, newnode, func_tlist);
	Node_Copy(from, newnode, func_planlist);

	return newnode;
}

/* ----------------
 *		_copyAggref
 * ----------------
 */
static Aggref *
_copyAggref(Aggref *from)
{
	Aggref	   *newnode = makeNode(Aggref);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->aggname = pstrdup(from->aggname);
	newnode->basetype = from->basetype;
	newnode->aggtype = from->aggtype;
	Node_Copy(from, newnode, target);
	newnode->aggno = from->aggno;
	newnode->usenulls = from->usenulls;

	return newnode;
}

/* ----------------
 *		_copySubLink
 * ----------------
 */
static SubLink *
_copySubLink(SubLink *from)
{
	SubLink    *newnode = makeNode(SubLink);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->subLinkType = from->subLinkType;
	newnode->useor = from->useor;
	Node_Copy(from, newnode, lefthand);
	Node_Copy(from, newnode, oper);
	Node_Copy(from, newnode, subselect);

	return newnode;
}

/* ----------------
 *		_copyCaseExpr
 * ----------------
 */
static CaseExpr *
_copyCaseExpr(CaseExpr *from)
{
	CaseExpr   *newnode = makeNode(CaseExpr);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->casetype = from->casetype;

	Node_Copy(from, newnode, arg);
	Node_Copy(from, newnode, args);
	Node_Copy(from, newnode, defresult);

	return newnode;
}

/* ----------------
 *		_copyCaseWhen
 * ----------------
 */
static CaseWhen *
_copyCaseWhen(CaseWhen *from)
{
	CaseWhen   *newnode = makeNode(CaseWhen);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	Node_Copy(from, newnode, expr);
	Node_Copy(from, newnode, result);

	return newnode;
}

static Array *
_copyArray(Array *from)
{
	Array	   *newnode = makeNode(Array);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->arrayelemtype = from->arrayelemtype;
	newnode->arrayelemlength = from->arrayelemlength;
	newnode->arrayelembyval = from->arrayelembyval;
	newnode->arrayndim = from->arrayndim;
	newnode->arraylow = from->arraylow;
	newnode->arrayhigh = from->arrayhigh;
	newnode->arraylen = from->arraylen;

	return newnode;
}

static ArrayRef *
_copyArrayRef(ArrayRef *from)
{
	ArrayRef   *newnode = makeNode(ArrayRef);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->refattrlength = from->refattrlength;
	newnode->refelemlength = from->refelemlength;
	newnode->refelemtype = from->refelemtype;
	newnode->refelembyval = from->refelembyval;

	Node_Copy(from, newnode, refupperindexpr);
	Node_Copy(from, newnode, reflowerindexpr);
	Node_Copy(from, newnode, refexpr);
	Node_Copy(from, newnode, refassgnexpr);

	return newnode;
}

/* ****************************************************************
 *						relation.h copy functions
 * ****************************************************************
 */

/* ----------------
 *		_copyRelOptInfo
 * ----------------
 */
/*
 *	when you change this, also make sure to fix up xfunc_copyRelOptInfo in
 *	planner/path/xfunc.c accordingly!!!
 *		-- JMH, 8/2/93
 */
static RelOptInfo *
_copyRelOptInfo(RelOptInfo *from)
{
	RelOptInfo *newnode = makeNode(RelOptInfo);
	int			i,
				len;

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->relids = listCopy(from->relids);

	newnode->indexed = from->indexed;
	newnode->pages = from->pages;
	newnode->tuples = from->tuples;
	newnode->size = from->size;
	newnode->width = from->width;
	Node_Copy(from, newnode, targetlist);
	Node_Copy(from, newnode, pathlist);
	Node_Copy(from, newnode, cheapestpath);
	newnode->pruneable = from->pruneable;

	if (from->classlist)
	{
		for (len = 0; from->classlist[len] != 0; len++)
			;
		newnode->classlist = (Oid *) palloc(sizeof(Oid) * (len + 1));
		for (i = 0; i < len; i++)
			newnode->classlist[i] = from->classlist[i];
		newnode->classlist[len] = 0;
	}

	if (from->indexkeys)
	{
		for (len = 0; from->indexkeys[len] != 0; len++)
			;
		newnode->indexkeys = (int *) palloc(sizeof(int) * (len + 1));
		for (i = 0; i < len; i++)
			newnode->indexkeys[i] = from->indexkeys[i];
		newnode->indexkeys[len] = 0;
	}

	newnode->relam = from->relam;
	newnode->indproc = from->indproc;
	Node_Copy(from, newnode, indpred);

	if (from->ordering)
	{
		for (len = 0; from->ordering[len] != 0; len++)
			;
		newnode->ordering = (Oid *) palloc(sizeof(Oid) * (len + 1));
		for (i = 0; i < len; i++)
			newnode->ordering[i] = from->ordering[i];
		newnode->ordering[len] = 0;
	}

	Node_Copy(from, newnode, restrictinfo);
	Node_Copy(from, newnode, joininfo);
	Node_Copy(from, newnode, innerjoin);

	return newnode;
}

/* ----------------
 *		CopyPathFields
 *
 *		This function copies the fields of the Path node.  It is used by
 *		all the copy functions for classes which inherit from Path.
 * ----------------
 */
static void
CopyPathFields(Path *from, Path *newnode)
{
	newnode->pathtype = from->pathtype;

	/*
	 * Modify the next line, since it causes the copying to cycle (i.e.
	 * the parent points right back here! -- JMH, 7/7/92. Old version:
	 * Node_Copy(from, newnode, parent);
	 */
	newnode->parent = from->parent;

	newnode->path_cost = from->path_cost;

	newnode->pathorder = makeNode(PathOrder);
	newnode->pathorder->ordtype = from->pathorder->ordtype;
	if (from->pathorder->ordtype == SORTOP_ORDER)
	{
		int			len,
					i;
		Oid		   *ordering = from->pathorder->ord.sortop;

		if (ordering)
		{
			for (len = 0; ordering[len] != 0; len++)
				;
			newnode->pathorder->ord.sortop = (Oid *) palloc(sizeof(Oid) * (len + 1));
			for (i = 0; i < len; i++)
				newnode->pathorder->ord.sortop[i] = ordering[i];
			newnode->pathorder->ord.sortop[len] = 0;
		}
	}
	else
		Node_Copy(from, newnode, pathorder->ord.merge);

	Node_Copy(from, newnode, pathkeys);

	newnode->outerjoincost = from->outerjoincost;

	newnode->joinid = listCopy(from->joinid);
	Node_Copy(from, newnode, loc_restrictinfo);
}

/* ----------------
 *		_copyPath
 * ----------------
 */
static Path *
_copyPath(Path *from)
{
	Path	   *newnode = makeNode(Path);

	CopyPathFields(from, newnode);

	return newnode;
}

/* ----------------
 *		_copyIndexPath
 * ----------------
 */
static IndexPath *
_copyIndexPath(IndexPath *from)
{
	IndexPath  *newnode = makeNode(IndexPath);

	/* ----------------
	 *	copy the node superclass fields
	 * ----------------
	 */
	CopyPathFields((Path *) from, (Path *) newnode);

	/* ----------------
	 *	copy remainder of node
	 * ----------------
	 */
	newnode->indexid = listCopy(from->indexid);
	Node_Copy(from, newnode, indexqual);

	if (from->indexkeys)
	{
		int			i,
					len;

		for (len = 0; from->indexkeys[len] != 0; len++)
			;
		newnode->indexkeys = (int *) palloc(sizeof(int) * (len + 1));
		for (i = 0; i < len; i++)
			newnode->indexkeys[i] = from->indexkeys[i];
		newnode->indexkeys[len] = 0;
	}

	return newnode;
}

/* ----------------
 *		CopyNestPathFields
 *
 *		This function copies the fields of the NestPath node.  It is used by
 *		all the copy functions for classes which inherit from NestPath.
 * ----------------
 */
static void
CopyNestPathFields(NestPath *from, NestPath *newnode)
{
	Node_Copy(from, newnode, pathinfo);
	Node_Copy(from, newnode, outerjoinpath);
	Node_Copy(from, newnode, innerjoinpath);
}

/* ----------------
 *		_copyNestPath
 * ----------------
 */
static NestPath *
_copyNestPath(NestPath *from)
{
	NestPath   *newnode = makeNode(NestPath);

	/* ----------------
	 *	copy the node superclass fields
	 * ----------------
	 */
	CopyPathFields((Path *) from, (Path *) newnode);
	CopyNestPathFields(from, newnode);

	return newnode;
}

/* ----------------
 *		_copyMergePath
 * ----------------
 */
static MergePath *
_copyMergePath(MergePath *from)
{
	MergePath  *newnode = makeNode(MergePath);

	/* ----------------
	 *	copy the node superclass fields
	 * ----------------
	 */
	CopyPathFields((Path *) from, (Path *) newnode);
	CopyNestPathFields((NestPath *) from, (NestPath *) newnode);

	/* ----------------
	 *	copy the remainder of the node
	 * ----------------
	 */
	Node_Copy(from, newnode, path_mergeclauses);
	Node_Copy(from, newnode, outersortkeys);
	Node_Copy(from, newnode, innersortkeys);

	return newnode;
}

/* ----------------
 *		_copyHashPath
 * ----------------
 */
static HashPath *
_copyHashPath(HashPath *from)
{
	HashPath   *newnode = makeNode(HashPath);

	/* ----------------
	 *	copy the node superclass fields
	 * ----------------
	 */
	CopyPathFields((Path *) from, (Path *) newnode);
	CopyNestPathFields((NestPath *) from, (NestPath *) newnode);