Files
scylladb/cql3/functions/native_scalar_function.hh
Avi Kivity 86c09046fd cql3: allow null function arguments and return types
Change function argument types and return values to bytes_opt.

Note: a comment in the code says that NULL arguments are not supported,
but it seems prudent to prepare for the day they will be.
2015-04-03 12:16:19 +02:00

82 lines
2.8 KiB
C++

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Modified by Cloudius Systems
*
* Copyright 2014 Cloudius Systems
*/
#ifndef CQL3_FUNCTIONS_NATIVE_SCALAR_FUNCTION_HH_
#define CQL3_FUNCTIONS_NATIVE_SCALAR_FUNCTION_HH_
#include "native_function.hh"
#include "scalar_function.hh"
#include "core/shared_ptr.hh"
namespace cql3 {
namespace functions {
/**
* Base class for the <code>ScalarFunction</code> native classes.
*/
class native_scalar_function : public native_function, public scalar_function {
protected:
native_scalar_function(sstring name, shared_ptr<abstract_type> return_type, std::vector<shared_ptr<abstract_type>> args_type)
: native_function(std::move(name), std::move(return_type), std::move(args_type)) {
}
public:
virtual bool is_aggregate() override {
return false;
}
};
template <typename Func, bool Pure>
class native_scalar_function_for : public native_scalar_function {
Func _func;
public:
native_scalar_function_for(sstring name,
data_type return_type,
const std::vector<data_type> arg_types,
Func&& func)
: native_scalar_function(std::move(name), std::move(return_type), std::move(arg_types))
, _func(std::forward<Func>(func)) {
}
virtual bytes_opt execute(serialization_format sf, const std::vector<bytes_opt>& parameters) override {
return _func(sf, parameters);
}
};
template <bool Pure, typename Func>
shared_ptr<function>
make_native_scalar_function(sstring name,
data_type return_type,
std::vector<data_type> args_type,
Func&& func) {
return ::make_shared<native_scalar_function_for<Func, Pure>>(std::move(name),
std::move(return_type),
std::move(args_type),
std::forward<Func>(func));
}
}
}
#endif /* CQL3_FUNCTIONS_NATIVE_SCALAR_FUNCTION_HH_ */