Files
rippled/include/xrpl/protocol/MultiApiJson.h
Vito Tumas 3e152fec74 refactor: use east const convention (#5409)
This change refactors the codebase to use the "east const convention", and adds a clang-format rule to follow this convention.
2025-05-08 11:00:42 +00:00

243 lines
8.2 KiB
C++

//------------------------------------------------------------------------------
/*
This file is part of rippled: https://github.com/ripple/rippled
Copyright (c) 2023 Ripple Labs Inc.
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL , DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
#ifndef RIPPLE_JSON_MULTIAPIJSON_H_INCLUDED
#define RIPPLE_JSON_MULTIAPIJSON_H_INCLUDED
#include <xrpl/beast/utility/instrumentation.h>
#include <xrpl/json/json_value.h>
#include <xrpl/protocol/ApiVersion.h>
#include <array>
#include <concepts>
#include <cstdlib>
#include <functional>
#include <limits>
#include <type_traits>
#include <utility>
namespace ripple {
namespace detail {
template <typename T>
constexpr bool is_integral_constant = false;
template <typename I, auto A>
constexpr bool is_integral_constant<std::integral_constant<I, A>&> = true;
template <typename I, auto A>
constexpr bool is_integral_constant<std::integral_constant<I, A> const&> = true;
template <typename T>
concept some_integral_constant = detail::is_integral_constant<T&>;
// This class is designed to wrap a collection of _almost_ identical Json::Value
// objects, indexed by version (i.e. there is some mapping of version to object
// index). It is used e.g. when we need to publish JSON data to users supporting
// different API versions. We allow manipulation and inspection of all objects
// at once with `isMember` and `set`, and also individual inspection and updates
// of an object selected by the user by version, using `visitor_t` nested type.
template <unsigned MinVer, unsigned MaxVer>
struct MultiApiJson
{
static_assert(MinVer <= MaxVer);
static constexpr auto
valid(unsigned int v) noexcept -> bool
{
return v >= MinVer && v <= MaxVer;
}
static constexpr auto
index(unsigned int v) noexcept -> std::size_t
{
return (v < MinVer) ? 0 : static_cast<std::size_t>(v - MinVer);
}
constexpr static std::size_t size = MaxVer + 1 - MinVer;
std::array<Json::Value, size> val = {};
explicit MultiApiJson(Json::Value const& init = {})
{
if (init == Json::Value{})
return; // All elements are already default-initialized
for (auto& v : val)
v = init;
}
void
set(char const* key, auto const& v)
requires std::constructible_from<Json::Value, decltype(v)>
{
for (auto& a : this->val)
a[key] = v;
}
// Intentionally not using class enum here, MultivarJson is scope enough
enum IsMemberResult : int { none = 0, some, all };
[[nodiscard]] IsMemberResult
isMember(char const* key) const
{
int count = 0;
for (auto& a : this->val)
if (a.isMember(key))
count += 1;
return (count == 0 ? none : (count < size ? some : all));
}
static constexpr struct visitor_t final
{
// integral_constant version, extra arguments
template <
typename Json,
unsigned int Version,
typename... Args,
typename Fn>
requires std::same_as<std::remove_cvref_t<Json>, MultiApiJson>
auto
operator()(
Json& json,
std::integral_constant<unsigned int, Version> const version,
Fn fn,
Args&&... args) const
-> std::invoke_result_t<
Fn,
decltype(json.val[0]),
std::integral_constant<unsigned int, Version>,
Args&&...>
{
static_assert(
valid(Version) && index(Version) >= 0 && index(Version) < size);
return std::invoke(
fn,
json.val[index(Version)],
version,
std::forward<Args>(args)...);
}
// integral_constant version, Json only
template <typename Json, unsigned int Version, typename Fn>
requires std::same_as<std::remove_cvref_t<Json>, MultiApiJson>
auto
operator()(
Json& json,
std::integral_constant<unsigned int, Version> const,
Fn fn) const -> std::invoke_result_t<Fn, decltype(json.val[0])>
{
static_assert(
valid(Version) && index(Version) >= 0 && index(Version) < size);
return std::invoke(fn, json.val[index(Version)]);
}
// unsigned int version, extra arguments
template <
typename Json,
typename Version,
typename... Args,
typename Fn>
requires(!some_integral_constant<Version>) &&
std::convertible_to<Version, unsigned> &&
std::same_as<std::remove_cvref_t<Json>, MultiApiJson>
auto
operator()(Json& json, Version version, Fn fn, Args&&... args) const
-> std::
invoke_result_t<Fn, decltype(json.val[0]), Version, Args&&...>
{
XRPL_ASSERT(
valid(version) && index(version) >= 0 && index(version) < size,
"ripple::detail::MultiApiJson::operator<Args...>() : valid "
"version");
return std::invoke(
fn,
json.val[index(version)],
version,
std::forward<Args>(args)...);
}
// unsigned int version, Json only
template <typename Json, typename Version, typename Fn>
requires(!some_integral_constant<Version>) &&
std::convertible_to<Version, unsigned> &&
std::same_as<std::remove_cvref_t<Json>, MultiApiJson>
auto
operator()(Json& json, Version version, Fn fn) const
-> std::invoke_result_t<Fn, decltype(json.val[0])>
{
XRPL_ASSERT(
valid(version) && index(version) >= 0 && index(version) < size,
"ripple::detail::MultiApiJson::operator() : valid version");
return std::invoke(fn, json.val[index(version)]);
}
} visitor = {};
auto
visit()
{
return [self = this](auto... args)
requires requires {
visitor(
std::declval<MultiApiJson&>(),
std::declval<decltype(args)>()...);
}
{ return visitor(*self, std::forward<decltype(args)>(args)...); };
}
auto
visit() const
{
return [self = this](auto... args)
requires requires {
visitor(
std::declval<MultiApiJson const&>(),
std::declval<decltype(args)>()...);
}
{ return visitor(*self, std::forward<decltype(args)>(args)...); };
}
template <typename... Args>
auto
visit(Args... args)
-> std::invoke_result_t<visitor_t, MultiApiJson&, Args...>
requires(sizeof...(args) > 0) &&
requires { visitor(*this, std::forward<decltype(args)>(args)...); }
{
return visitor(*this, std::forward<decltype(args)>(args)...);
}
template <typename... Args>
auto
visit(Args... args) const
-> std::invoke_result_t<visitor_t, MultiApiJson const&, Args...>
requires(sizeof...(args) > 0) &&
requires { visitor(*this, std::forward<decltype(args)>(args)...); }
{
return visitor(*this, std::forward<decltype(args)>(args)...);
}
};
} // namespace detail
// Wrapper for Json for all supported API versions.
using MultiApiJson = detail::
MultiApiJson<RPC::apiMinimumSupportedVersion, RPC::apiMaximumValidVersion>;
} // namespace ripple
#endif