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/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed 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.
*/
#ifndef _INIT_KEYWORD_MAP_H_
#define _INIT_KEYWORD_MAP_H_
#include <map>
#include <string>
#include <android-base/stringprintf.h>
namespace android {
namespace init {
template <typename Function>
class KeywordMap {
public:
using FunctionInfo = std::tuple<std::size_t, std::size_t, Function>;
using Map = std::map<std::string, FunctionInfo>;
virtual ~KeywordMap() {
}
const Function FindFunction(const std::vector<std::string>& args, std::string* err) const {
using android::base::StringPrintf;
if (args.empty()) {
*err = "keyword needed, but not provided";
return nullptr;
}
auto& keyword = args[0];
auto num_args = args.size() - 1;
auto function_info_it = map().find(keyword);
if (function_info_it == map().end()) {
*err = StringPrintf("invalid keyword '%s'", keyword.c_str());
return nullptr;
}
auto function_info = function_info_it->second;
auto min_args = std::get<0>(function_info);
auto max_args = std::get<1>(function_info);
if (min_args == max_args && num_args != min_args) {
*err = StringPrintf("%s requires %zu argument%s",
keyword.c_str(), min_args,
(min_args > 1 || min_args == 0) ? "s" : "");
return nullptr;
}
if (num_args < min_args || num_args > max_args) {
if (max_args == std::numeric_limits<decltype(max_args)>::max()) {
*err = StringPrintf("%s requires at least %zu argument%s",
keyword.c_str(), min_args,
min_args > 1 ? "s" : "");
} else {
*err = StringPrintf("%s requires between %zu and %zu arguments",
keyword.c_str(), min_args, max_args);
}
return nullptr;
}
return std::get<Function>(function_info);
}
private:
// Map of keyword ->
// (minimum number of arguments, maximum number of arguments, function pointer)
virtual const Map& map() const = 0;
};
} // namespace init
} // namespace android
#endif
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