C++ PG_RETURN_OID函数代码示例

/*
 * text_regclass: convert text to regclass
 *
 * This could be replaced by CoerceViaIO, except that we need to treat
 * text-to-regclass as an implicit cast to support legacy forms of nextval()
 * and related functions.
 */
Datum
text_regclass(PG_FUNCTION_ARGS)
{
	text	   *relname = PG_GETARG_TEXT_P(0);
	Oid			result;
	RangeVar   *rv;

	rv = makeRangeVarFromNameList(textToQualifiedNameList(relname));

	/* We might not even have permissions on this relation; don't lock it. */
	result = RangeVarGetRelid(rv, NoLock, false);

	PG_RETURN_OID(result);
}

/*
 * lo_import -
 *	  imports a file as an (inversion) large object.
 */
Datum
lo_import(PG_FUNCTION_ARGS)
{
	text	   *filename = PG_GETARG_TEXT_PP(0);

#ifdef PGXC
	ereport(ERROR,
			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
			 errmsg("Postgres-XC does not support large object yet"),
			 errdetail("The feature is not currently supported")));
#endif

	PG_RETURN_OID(lo_import_internal(filename, InvalidOid));
}

Datum
lo_create(PG_FUNCTION_ARGS)
{
	Oid			lobjId = PG_GETARG_OID(0);

	/*
	 * We don't actually need to store into fscxt, but create it anyway to
	 * ensure that AtEOXact_LargeObject knows there is state to clean up
	 */
	CreateFSContext();

	lobjId = inv_create(lobjId);

	PG_RETURN_OID(lobjId);
}

Datum
i8tooid(PG_FUNCTION_ARGS)
{
    int64		arg = PG_GETARG_INT64(0);
    Oid			result;

    result = (Oid) arg;

    /* Test for overflow by reverse-conversion. */
    if ((int64) result != arg)
        ereport(ERROR,
                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                 errmsg("OID out of range")));

    PG_RETURN_OID(result);
}

/*
 * to_regtype		- converts "typename" to type OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regtype(PG_FUNCTION_ARGS)
{
	char	   *typ_name = PG_GETARG_CSTRING(0);
	Oid			result;
	int32		typmod;

	/*
	 * Invoke the full parser to deal with special cases such as array syntax.
	 */
	parseTypeString(typ_name, &result, &typmod, true);

	if (OidIsValid(result))
		PG_RETURN_OID(result);
	else
		PG_RETURN_NULL();
}

/*
 * Create LO with initial contents given by a bytea argument
 */
Datum
lo_from_bytea(PG_FUNCTION_ARGS)
{
	Oid			loOid = PG_GETARG_OID(0);
	bytea	   *str = PG_GETARG_BYTEA_PP(1);
	LargeObjectDesc *loDesc;
	int written PG_USED_FOR_ASSERTS_ONLY;

	CreateFSContext();

	loOid = inv_create(loOid);
	loDesc = inv_open(loOid, INV_WRITE, fscxt);
	written = inv_write(loDesc, VARDATA_ANY(str), VARSIZE_ANY_EXHDR(str));
	Assert(written == VARSIZE_ANY_EXHDR(str));
	inv_close(loDesc);

	PG_RETURN_OID(loOid);
}

Datum
pg_highest_oid(PG_FUNCTION_ARGS __attribute__((unused)))
{
	Oid result;
	Oid max_from_segdbs;

	result = ShmemVariableCache->nextOid;

	if (Gp_role == GP_ROLE_DISPATCH)
	{
		max_from_segdbs = get_max_oid_from_segDBs();

		if (max_from_segdbs > result)
			result = max_from_segdbs;
	}

	PG_RETURN_OID(result);
}

Datum
lo_create(PG_FUNCTION_ARGS)
{
	Oid			lobjId = PG_GETARG_OID(0);

	ereport(ERROR,
		(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
		 errmsg("large objects are not supported")));

	/*
	 * We don't actually need to store into fscxt, but create it anyway to
	 * ensure that AtEOXact_LargeObject knows there is state to clean up
	 */
	CreateFSContext();

	lobjId = inv_create(lobjId);

	PG_RETURN_OID(lobjId);
}

/*
 * to_regproc	- converts "proname" to proc OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regproc(PG_FUNCTION_ARGS)
{
	char	   *pro_name = PG_GETARG_CSTRING(0);
	List	   *names;
	FuncCandidateList clist;

	/*
	 * Parse the name into components and see if it matches any pg_proc
	 * entries in the current search path.
	 */
	names = stringToQualifiedNameList(pro_name);
	clist = FuncnameGetCandidates(names, -1, NIL, false, false, true);

	if (clist == NULL || clist->next != NULL)
		PG_RETURN_NULL();

	PG_RETURN_OID(clist->oid);
}

/*
 * to_regoper		- converts "oprname" to operator OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regoper(PG_FUNCTION_ARGS)
{
	char	   *opr_name = PG_GETARG_CSTRING(0);
	List	   *names;
	FuncCandidateList clist;

	/*
	 * Parse the name into components and see if it matches any pg_operator
	 * entries in the current search path.
	 */
	names = stringToQualifiedNameList(opr_name);
	clist = OpernameGetCandidates(names, '\0', true);

	if (clist == NULL || clist->next != NULL)
		PG_RETURN_NULL();

	PG_RETURN_OID(clist->oid);
}

Datum
text_oid(PG_FUNCTION_ARGS)
{
	text	   *string = PG_GETARG_TEXT_P(0);
	Oid			result;
	int			len;
	char	   *str;

	len = (VARSIZE(string) - VARHDRSZ);

	str = palloc(len + 1);
	memcpy(str, VARDATA(string), len);
	*(str + len) = '\0';

	result = oidin_subr("text_oid", str, NULL);

	pfree(str);

	PG_RETURN_OID(result);
}

/* Binary I/O support */
Datum
enum_recv(PG_FUNCTION_ARGS)
{
	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
	Oid			enumtypoid = PG_GETARG_OID(1);
	Oid			enumoid;
	HeapTuple	tup;
	char	   *name;
	int			nbytes;

	name = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);

	/* must check length to prevent Assert failure within SearchSysCache */
	if (strlen(name) >= NAMEDATALEN)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
				 errmsg("invalid input value for enum %s: \"%s\"",
						format_type_be(enumtypoid),
						name)));

	tup = SearchSysCache2(ENUMTYPOIDNAME,
						  ObjectIdGetDatum(enumtypoid),
						  CStringGetDatum(name));
	if (!HeapTupleIsValid(tup))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
				 errmsg("invalid input value for enum %s: \"%s\"",
						format_type_be(enumtypoid),
						name)));

	/* check it's safe to use in SQL */
	check_safe_enum_use(tup);

	enumoid = HeapTupleGetOid(tup);

	ReleaseSysCache(tup);

	pfree(name);

	PG_RETURN_OID(enumoid);
}

/*
 * to_regclass		- converts "classname" to class OID
 *
 * If the name is not found, we return NULL.
 */
Datum
to_regclass(PG_FUNCTION_ARGS)
{
	char	   *class_name = PG_GETARG_CSTRING(0);
	Oid			result;
	List	   *names;

	/*
	 * Parse the name into components and see if it matches any pg_class
	 * entries in the current search path.
	 */
	names = stringToQualifiedNameList(class_name);

	/* We might not even have permissions on this relation; don't lock it. */
	result = RangeVarGetRelid(makeRangeVarFromNameList(names), NoLock, true);

	if (OidIsValid(result))
		PG_RETURN_OID(result);
	else
		PG_RETURN_NULL();
}

Datum
enum_last(PG_FUNCTION_ARGS)
{
	Oid			enumtypoid;
	Oid			max = InvalidOid;
	CatCList   *list;
	int			num,
				i;

	/*
	 * We rely on being able to get the specific enum type from the calling
	 * expression tree.  Notice that the actual value of the argument isn't
	 * examined at all; in particular it might be NULL.
	 */
	enumtypoid = get_fn_expr_argtype(fcinfo->flinfo, 0);
	if (enumtypoid == InvalidOid)
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("could not determine actual enum type")));

	list = SearchSysCacheList(ENUMTYPOIDNAME, 1,
							  ObjectIdGetDatum(enumtypoid),
							  0, 0, 0);
	num = list->n_members;
	for (i = 0; i < num; i++)
	{
		Oid			valoid = HeapTupleHeaderGetOid(list->members[i]->tuple.t_data);

		if (!OidIsValid(max) || valoid > max)
			max = valoid;
	}

	ReleaseCatCacheList(list);

	if (!OidIsValid(max))		/* should not happen */
		elog(ERROR, "no values found for enum %s",
			 format_type_be(enumtypoid));

	PG_RETURN_OID(max);
}

Datum
enum_in(PG_FUNCTION_ARGS)
{
	char	   *name = PG_GETARG_CSTRING(0);
	Oid			enumtypoid = PG_GETARG_OID(1);
	Oid			enumoid;
	HeapTuple	tup;

	/* must check length to prevent Assert failure within SearchSysCache */
	if (strlen(name) >= NAMEDATALEN)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
				 errmsg("invalid input value for enum %s: \"%s\"",
						format_type_be(enumtypoid),
						name)));

	tup = SearchSysCache2(ENUMTYPOIDNAME,
						  ObjectIdGetDatum(enumtypoid),
						  CStringGetDatum(name));
	if (!HeapTupleIsValid(tup))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
				 errmsg("invalid input value for enum %s: \"%s\"",
						format_type_be(enumtypoid),
						name)));

	/* check it's safe to use in SQL */
	check_safe_enum_use(tup);

	/*
	 * This comes from pg_enum.oid and stores system oids in user tables. This
	 * oid must be preserved by binary upgrades.
	 */
	enumoid = HeapTupleGetOid(tup);

	ReleaseSysCache(tup);

	PG_RETURN_OID(enumoid);
}