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/*
* Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef RTC_BASE_EXPERIMENTS_STRUCT_PARAMETERS_PARSER_H_
#define RTC_BASE_EXPERIMENTS_STRUCT_PARAMETERS_PARSER_H_
#include <functional>
#include <map>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "absl/memory/memory.h"
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "rtc_base/experiments/field_trial_parser.h"
#include "rtc_base/experiments/field_trial_units.h"
#include "rtc_base/string_encode.h"
namespace webrtc {
namespace struct_parser_impl {
struct TypedMemberParser {
public:
bool (*parse)(absl::string_view src, void* target);
void (*encode)(const void* src, std::string* target);
};
struct MemberParameter {
const char* key;
void* member_ptr;
TypedMemberParser parser;
};
template <typename T>
class TypedParser {
public:
static bool Parse(absl::string_view src, void* target);
static void Encode(const void* src, std::string* target);
};
// Instantiated in cc file to avoid duplication during compile. Add additional
// parsers as needed. Generally, try to use these suggested types even if the
// context where the value is used might require a different type. For instance,
// a size_t representing a packet size should use an int parameter as there's no
// need to support packet sizes larger than INT32_MAX.
extern template class TypedParser<bool>;
extern template class TypedParser<double>;
extern template class TypedParser<int>;
extern template class TypedParser<unsigned>;
extern template class TypedParser<absl::optional<double>>;
extern template class TypedParser<absl::optional<int>>;
extern template class TypedParser<absl::optional<unsigned>>;
extern template class TypedParser<DataRate>;
extern template class TypedParser<DataSize>;
extern template class TypedParser<TimeDelta>;
extern template class TypedParser<absl::optional<DataRate>>;
extern template class TypedParser<absl::optional<DataSize>>;
extern template class TypedParser<absl::optional<TimeDelta>>;
template <typename T>
void AddMembers(MemberParameter* out, const char* key, T* member) {
*out = MemberParameter{
key, member,
TypedMemberParser{&TypedParser<T>::Parse, &TypedParser<T>::Encode}};
}
template <typename T, typename... Args>
void AddMembers(MemberParameter* out,
const char* key,
T* member,
Args... args) {
AddMembers(out, key, member);
AddMembers(++out, args...);
}
} // namespace struct_parser_impl
class StructParametersParser {
public:
template <typename T, typename... Args>
static std::unique_ptr<StructParametersParser> Create(const char* first_key,
T* first_member,
Args... args) {
std::vector<struct_parser_impl::MemberParameter> members(
sizeof...(args) / 2 + 1);
struct_parser_impl::AddMembers(&members.front(), std::move(first_key),
first_member, args...);
return absl::WrapUnique(new StructParametersParser(std::move(members)));
}
void Parse(absl::string_view src);
std::string Encode() const;
private:
explicit StructParametersParser(
std::vector<struct_parser_impl::MemberParameter> members);
std::vector<struct_parser_impl::MemberParameter> members_;
};
} // namespace webrtc
#endif // RTC_BASE_EXPERIMENTS_STRUCT_PARAMETERS_PARSER_H_
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