dolphin/Source/Core/Common/Config/ConfigInfo.h
Pierre Bourdon e149ad4f0a
treewide: convert GPLv2+ license info to SPDX tags
SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
2021-07-05 04:35:56 +02:00

125 lines
3.3 KiB
C++

// Copyright 2017 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <mutex>
#include <shared_mutex>
#include <string>
#include <type_traits>
#include <utility>
#include "Common/CommonTypes.h"
#include "Common/Config/Enums.h"
namespace Config
{
namespace detail
{
// std::underlying_type may only be used with enum types, so make sure T is an enum type first.
template <typename T>
using UnderlyingType = typename std::enable_if_t<std::is_enum<T>{}, std::underlying_type<T>>::type;
} // namespace detail
struct Location
{
System system;
std::string section;
std::string key;
bool operator==(const Location& other) const;
bool operator!=(const Location& other) const;
bool operator<(const Location& other) const;
};
template <typename T>
struct CachedValue
{
T value;
u64 config_version;
};
template <typename T>
class Info
{
public:
constexpr Info(const Location& location, const T& default_value)
: m_location{location}, m_default_value{default_value}, m_cached_value{default_value, 0}
{
}
Info(const Info<T>& other) { *this = other; }
// Not thread-safe
Info(Info<T>&& other) { *this = std::move(other); }
// Make it easy to convert Info<Enum> into Info<UnderlyingType<Enum>>
// so that enum settings can still easily work with code that doesn't care about the enum values.
template <typename Enum,
std::enable_if_t<std::is_same<T, detail::UnderlyingType<Enum>>::value>* = nullptr>
Info(const Info<Enum>& other)
{
*this = other;
}
Info<T>& operator=(const Info<T>& other)
{
m_location = other.GetLocation();
m_default_value = other.GetDefaultValue();
m_cached_value = other.GetCachedValue();
return *this;
}
// Not thread-safe
Info<T>& operator=(Info<T>&& other)
{
m_location = std::move(other.m_location);
m_default_value = std::move(other.m_default_value);
m_cached_value = std::move(other.m_cached_value);
return *this;
}
// Make it easy to convert Info<Enum> into Info<UnderlyingType<Enum>>
// so that enum settings can still easily work with code that doesn't care about the enum values.
template <typename Enum,
std::enable_if_t<std::is_same<T, detail::UnderlyingType<Enum>>::value>* = nullptr>
Info<T>& operator=(const Info<Enum>& other)
{
m_location = other.GetLocation();
m_default_value = static_cast<T>(other.GetDefaultValue());
m_cached_value = other.template GetCachedValueCasted<T>();
return *this;
}
constexpr const Location& GetLocation() const { return m_location; }
constexpr const T& GetDefaultValue() const { return m_default_value; }
CachedValue<T> GetCachedValue() const
{
std::shared_lock lock(m_cached_value_mutex);
return m_cached_value;
}
template <typename U>
CachedValue<U> GetCachedValueCasted() const
{
std::shared_lock lock(m_cached_value_mutex);
return CachedValue<U>{static_cast<U>(m_cached_value.value), m_cached_value.config_version};
}
void SetCachedValue(const CachedValue<T>& cached_value) const
{
std::unique_lock lock(m_cached_value_mutex);
if (m_cached_value.config_version < cached_value.config_version)
m_cached_value = cached_value;
}
private:
Location m_location;
T m_default_value;
mutable CachedValue<T> m_cached_value;
mutable std::shared_mutex m_cached_value_mutex;
};
} // namespace Config