readfuncs.c

关系型数据库 Postgresql 6.5.2

	 *
	 * GJK:  Since I am parsing this stuff, I'll just ignore the addresses,
	 * and initialize these pointers to NULL.
	 */

	token = lsptok(NULL, &length);		/* get :outerjoinpath */
	token = lsptok(NULL, &length);		/* get @ */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->jpath.outerjoinpath = NULL;

	token = lsptok(NULL, &length);		/* get :innerjoinpath */
	token = lsptok(NULL, &length);		/* get @ */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->jpath.innerjoinpath = NULL;

	token = lsptok(NULL, &length);		/* get :outerjoincost */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->jpath.path.outerjoincost = (Cost) atof(token);

	token = lsptok(NULL, &length);		/* get :joinid */
	local_node->jpath.path.joinid = toIntList(nodeRead(true));	/* now read it */

	token = lsptok(NULL, &length);		/* get :path_mergeclauses */
	local_node->path_mergeclauses = nodeRead(true);		/* now read it */

	token = lsptok(NULL, &length);		/* get :outersortkeys */
	local_node->outersortkeys = nodeRead(true); /* now read it */

	token = lsptok(NULL, &length);		/* get :innersortkeys */
	local_node->innersortkeys = nodeRead(true); /* now read it */

	return local_node;
}

/* ----------------
 *		_readHashPath
 *
 *	HashPath is a subclass of NestPath.
 * ----------------
 */
static HashPath *
_readHashPath()
{
	HashPath   *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(HashPath);

	token = lsptok(NULL, &length);		/* get :pathtype */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->jpath.path.pathtype = atol(token);

	token = lsptok(NULL, &length);		/* get :cost */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->jpath.path.path_cost = (Cost) atof(token);

	token = lsptok(NULL, &length);		/* get :pathorder */
	local_node->jpath.path.pathorder = nodeRead(true);	/* now read it */

	token = lsptok(NULL, &length);		/* get :pathkeys */
	local_node->jpath.path.pathkeys = nodeRead(true);	/* now read it */

	token = lsptok(NULL, &length);		/* get :pathinfo */
	local_node->jpath.pathinfo = nodeRead(true);		/* now read it */

	/*
	 * Not sure if these are nodes; they're declared as "struct path *".
	 * For now, i'll just print the addresses.
	 *
	 * GJK:  Since I am parsing this stuff, I'll just ignore the addresses,
	 * and initialize these pointers to NULL.
	 */

	token = lsptok(NULL, &length);		/* get :outerjoinpath */
	token = lsptok(NULL, &length);		/* get @ */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->jpath.outerjoinpath = NULL;

	token = lsptok(NULL, &length);		/* get :innerjoinpath */
	token = lsptok(NULL, &length);		/* get @ */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->jpath.innerjoinpath = NULL;

	token = lsptok(NULL, &length);		/* get :outerjoincost */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->jpath.path.outerjoincost = (Cost) atof(token);

	token = lsptok(NULL, &length);		/* get :joinid */
	local_node->jpath.path.joinid = toIntList(nodeRead(true));	/* now read it */

	token = lsptok(NULL, &length);		/* get :path_hashclauses */
	local_node->path_hashclauses = nodeRead(true);		/* now read it */

	token = lsptok(NULL, &length);		/* get :outerhashkeys */
	local_node->outerhashkeys = nodeRead(true); /* now read it */

	token = lsptok(NULL, &length);		/* get :innerhashkeys */
	local_node->innerhashkeys = nodeRead(true); /* now read it */

	return local_node;
}

/* ----------------
 *		_readOrderKey
 *
 *	OrderKey is a subclass of Node.
 * ----------------
 */
static OrderKey *
_readOrderKey()
{
	OrderKey   *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(OrderKey);

	token = lsptok(NULL, &length);		/* get :attribute_number */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->attribute_number = atoi(token);

	token = lsptok(NULL, &length);		/* get :array_index */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->array_index = strtoul(token, NULL, 10);

	return local_node;
}

/* ----------------
 *		_readJoinKey
 *
 *	JoinKey is a subclass of Node.
 * ----------------
 */
static JoinKey *
_readJoinKey()
{
	JoinKey    *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(JoinKey);

	token = lsptok(NULL, &length);		/* get :outer */
	local_node->outer = nodeRead(true); /* now read it */

	token = lsptok(NULL, &length);		/* get :inner */
	local_node->inner = nodeRead(true); /* now read it */

	return local_node;
}

/* ----------------
 *		_readMergeOrder
 *
 *	MergeOrder is a subclass of Node.
 * ----------------
 */
static MergeOrder *
_readMergeOrder()
{
	MergeOrder *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(MergeOrder);
	token = lsptok(NULL, &length);		/* get :join_operator */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->join_operator = atol(token);

	token = lsptok(NULL, &length);		/* get :left_operator */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->left_operator = atol(token);

	token = lsptok(NULL, &length);		/* get :right_operator */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->right_operator = atol(token);

	token = lsptok(NULL, &length);		/* get :left_type */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->left_type = atol(token);

	token = lsptok(NULL, &length);		/* get :right_type */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->right_type = atol(token);

	return local_node;
}

/* ----------------
 *		_readRestrictInfo
 *
 *	RestrictInfo is a subclass of Node.
 * ----------------
 */
static RestrictInfo *
_readRestrictInfo()
{
	RestrictInfo *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(RestrictInfo);

	token = lsptok(NULL, &length);		/* get :clause */
	local_node->clause = nodeRead(true);		/* now read it */

	token = lsptok(NULL, &length);		/* get :selectivity */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->selectivity = atof(token);

	token = lsptok(NULL, &length);		/* get :notclause */
	token = lsptok(NULL, &length);		/* now read it */

	if (!strncmp(token, "true", 4))
		local_node->notclause = true;
	else
		local_node->notclause = false;

	token = lsptok(NULL, &length);		/* get :indexids */
	local_node->indexids = nodeRead(true);		/* now read it */

	token = lsptok(NULL, &length);		/* get :mergejoinorder */
	local_node->mergejoinorder = (MergeOrder *) nodeRead(true);

	token = lsptok(NULL, &length);		/* get :hashjoinoperator */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->hashjoinoperator = atol(token);

	return local_node;
}

/* ----------------
 *		_readJoinMethod
 *
 *	JoinMethod is a subclass of Node.
 * ----------------
 */
static JoinMethod *
_readJoinMethod()
{
	JoinMethod *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(JoinMethod);

	token = lsptok(NULL, &length);		/* get :jmkeys */
	local_node->jmkeys = nodeRead(true);		/* now read it */

	token = lsptok(NULL, &length);		/* get :clauses */
	local_node->clauses = nodeRead(true);		/* now read it */

	return local_node;
}

/* ----------------
 *		_readHashInfo
 *
 * HashInfo is a subclass of JoinMethod.
 * ----------------
 */
static HashInfo *
_readHashInfo()
{
	HashInfo   *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(HashInfo);

	token = lsptok(NULL, &length);		/* get :hashop */
	token = lsptok(NULL, &length);		/* now read it */

	local_node->hashop = strtoul(token, NULL, 10);

	token = lsptok(NULL, &length);		/* get :jmkeys */
	local_node->jmethod.jmkeys = nodeRead(true);		/* now read it */

	token = lsptok(NULL, &length);		/* get :clauses */
	local_node->jmethod.clauses = nodeRead(true);		/* now read it */

	return local_node;
}

/* ----------------
 *		_readJoinInfo()
 *
 *	JoinInfo is a subclass of Node.
 * ----------------
 */
static JoinInfo *
_readJoinInfo()
{
	JoinInfo   *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(JoinInfo);

	token = lsptok(NULL, &length);		/* get :unjoined_relids */
	local_node->unjoined_relids = toIntList(nodeRead(true));	/* now read it */

	token = lsptok(NULL, &length);		/* get :jinfo_restrictinfo */
	local_node->jinfo_restrictinfo = nodeRead(true);	/* now read it */

	token = lsptok(NULL, &length);		/* get :mergejoinable */

	if (!strncmp(token, "true", 4))
		local_node->mergejoinable = true;
	else
		local_node->mergejoinable = false;

	token = lsptok(NULL, &length);		/* get :hashjoinable */

	if (!strncmp(token, "true", 4))
		local_node->hashjoinable = true;
	else
		local_node->hashjoinable = false;

	return local_node;
}

/* ----------------
 *		_readIter()
 *
 * ----------------
 */
static Iter *
_readIter()
{
	Iter	   *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(Iter);

	token = lsptok(NULL, &length);		/* eat :iterexpr */
	local_node->iterexpr = nodeRead(true);		/* now read it */

	return local_node;
}


/* ----------------
 *		parsePlanString
 *
 * Given a character string containing a plan, parsePlanString sets up the
 * plan structure representing that plan.
 *
 * The string passed to parsePlanString must be null-terminated.
 * ----------------
 */
Node *
parsePlanString(void)
{
	char	   *token;
	int			length;
	void	   *return_value = NULL;

	token = lsptok(NULL, &length);

	if (!strncmp(token, "PLAN", length))
		return_value = _readPlan();
	else if (!strncmp(token, "RESULT", length))
		return_value = _readResult();
	else if (!strncmp(token, "APPEND", length))
		return_value = _readAppend();
	else if (!strncmp(token, "JOIN", length))
		return_value = _readJoin();
	else if (!strncmp(token, "NESTLOOP", length))
		return_value = _readNestLoop();
	else if (!strncmp(token, "MERGEJOIN", length))
		return_value = _readMergeJoin();
	else if (!strncmp(token, "HASHJOIN", length))
		return_value = _readHashJoin();
	else if (!strncmp(token, "SCAN", length))
		return_value = _readScan();
	else if (!strncmp(token, "SEQSCAN", length))
		return_value = _readSeqScan();
	else if (!strncmp(token, "INDEXSCAN", length))
		return_value = _readIndexScan();
	else if (!strncmp(token, "NONAME", length))
		return_value = _readNoname();
	else if (!strncmp(token, "SORT", length))
		return_value = _readSort();
	else if (!strncmp(token, "AGGREG", length))
		return_value = _readAggref();
	else if (!strncmp(token, "SUBLINK", length))
		return_value = _readSubLink();
	else if (!strncmp(token, "AGG", length))
		return_value = _readAgg();
	else if (!strncmp(token, "UNIQUE", length))
		return_value = _readUnique();
	else if (!strncmp(token, "HASH", length))
		return_value = _readHash();
	else if (!strncmp(token, "RESDOM", length))
		return_value = _readResdom();
	else if (!strncmp(token, "EXPR", length))
		return_value = _readExpr();
	else if (!strncmp(token, "ARRAYREF", length))
		return_value = _readArrayRef();
	else if (!strncmp(token, "ARRAY", length))
		return_value = _readArray();
	else if (!strncmp(token, "VAR", length))
		return_value = _readVar();
	else if (!strncmp(token, "CONST", length))
		return_value = _readConst();
	else if (!strncmp(token, "FUNC", length))
		return_value = _readFunc();
	else if (!strncmp(token, "OPER", length))
		return_value = _readOper();
	else if (!strncmp(token, "PARAM", length))
		return_value = _readParam();
	else if (!strncmp(token, "ESTATE", length))
		return_value = _readEState();
	else if (!strncmp(token, "RELOPTINFO", length))
		return_value = _readRelOptInfo();
	else if (!strncmp(token, "TARGETENTRY", length))
		return_value = _readTargetEntry();
	else if (!strncmp(token, "RTE", length))
		return_value = _readRangeTblEntry();
	else if (!strncmp(token, "PATHORDER", length))
		return_value = _readPathOrder();
	else if (!strncmp(token, "PATH", length))
		return_value = _readPath();
	else if (!strncmp(token, "INDEXPATH", length))
		return_value = _readIndexPath();
	else if (!strncmp(token, "NESTPATH", length))
		return_value = _readNestPath();
	else if (!strncmp(token, "MERGEPATH", length))
		return_value = _readMergePath();
	else if (!strncmp(token, "HASHPATH", length))
		return_value = _readHashPath();
	else if (!strncmp(token, "ORDERKEY", length))
		return_value = _readOrderKey();
	else if (!strncmp(token, "JOINKEY", length))
		return_value = _readJoinKey();
	else if (!strncmp(token, "MERGEORDER", length))
		return_value = _readMergeOrder();
	else if (!strncmp(token, "RETRICTINFO", length))
		return_value = _readRestrictInfo();
	else if (!strncmp(token, "JOINMETHOD", length))
		return_value = _readJoinMethod();
	else if (!strncmp(token, "JOININFO", length))
		return_value = _readJoinInfo();
	else if (!strncmp(token, "HASHINFO", length))
		return_value = _readHashInfo();
	else if (!strncmp(token, "ITER", length))
		return_value = _readIter();
	else if (!strncmp(token, "QUERY", length))
		return_value = _readQuery();
	else if (!strncmp(token, "SORTCLAUSE", length))
		return_value = _readSortClause();
	else if (!strncmp(token, "GROUPCLAUSE", length))
		return_value = _readGroupClause();
	else if (!strncmp(token, "CASE", length))
		return_value = _readCaseExpr();
	else if (!strncmp(token, "WHEN", length))
		return_value = _readCaseWhen();
	else if (!strncmp(token, "ROWMARK", length))
		return_value = _readRowMark();
	else
		elog(ERROR, "badly formatted planstring \"%.10s\"...\n", token);

	return (Node *) return_value;
}

/*------------------------------------------------------------*/

/* ----------------
 *		readDatum
 *
 * given a string representation of the value of the given type,
 * create the appropriate Datum
 * ----------------
 */
static Datum
readDatum(Oid type)
{
	int			length;
	int			tokenLength;
	char	   *token;
	bool		byValue;
	Datum		res;
	char	   *s;
	int			i;

	byValue = get_typbyval(type);

	/*
	 * read the actual length of the value
	 */
	token = lsptok(NULL, &tokenLength);
	length = atoi(token);
	token = lsptok(NULL, &tokenLength); /* skip the '[' */

	if (byValue)
	{
		if (length > sizeof(Datum))
			elog(ERROR, "readValue: byval & length = %d", length);
		s = (char *) (&res);
		for (i = 0; i < sizeof(Datum); i++)
		{
			token = lsptok(NULL, &tokenLength);
			s[i] = (char) atoi(token);
		}
	}
	else if (length <= 0)
		s = NULL;
	else if (length >= 1)
	{
		s = (char *) palloc(length);
		Assert(s != NULL);
		for (i = 0; i < length; i++)
		{
			token = lsptok(NULL, &tokenLength);
			s[i] = (char) atoi(token);
		}
		res = PointerGetDatum(s);
	}

	token = lsptok(NULL, &tokenLength); /* skip the ']' */
	if (token[0] != ']')
		elog(ERROR, "readValue: ']' expected, length =%d", length);

	return res;
}