Files
clice/include/Support/Binary.h
2025-02-03 01:26:37 +08:00

353 lines
10 KiB
C++

#pragma once
#include <vector>
#include <cstdint>
#include <cstring>
#include <cstdlib>
#include "Enum.h"
#include "Struct.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
namespace clice::binary {
namespace impl {
template <typename Tuple>
struct tuple_uniuqe {
using type = Tuple;
};
/// Uniuqe the types in the tuple.
template <typename Tuple>
using tuple_uniuqe_t = typename tuple_uniuqe<Tuple>::type;
template <typename T, typename... Ts>
requires (!std::is_same_v<T, Ts> && ...)
struct tuple_uniuqe<std::tuple<T, Ts...>> {
using type = decltype(std::tuple_cat(std::declval<std::tuple<T>>(),
std::declval<tuple_uniuqe_t<std::tuple<Ts...>>>()));
};
template <typename T, typename... Ts>
requires (std::is_same_v<T, Ts> || ...)
struct tuple_uniuqe<std::tuple<T, Ts...>> {
using type = tuple_uniuqe_t<std::tuple<Ts...>>;
};
template <typename T>
struct array {
uint32_t offset;
uint32_t size;
};
using string = array<char>;
/// Check whether a type can be directly binarized.
template <typename T>
constexpr inline bool is_directly_binarizable_v = false;
template <typename T>
requires (std::is_integral_v<T> || refl::reflectable_enum<T>)
constexpr inline bool is_directly_binarizable_v<T> = true;
template <refl::reflectable_struct T>
constexpr inline bool is_directly_binarizable_v<T> = refl::member_types<T>::apply(
[]<typename... Ts>() { return (is_directly_binarizable_v<Ts> && ...); });
template <typename T>
struct binarify;
/// Transform a type to its binary representation. All `std::string`
/// will be transformed to `string`. All `std::vector<T>` will be
/// transformed to `array<T>`.
template <typename T>
using binarify_t = typename binarify<T>::type;
/// For types that can be directly binarized, the binary representation
/// is the same as the original type.
template <typename T>
requires (is_directly_binarizable_v<T>)
struct binarify<T> {
using type = T;
};
template <>
struct binarify<std::string> {
using type = string;
};
template <typename V>
struct binarify<std::vector<V>> {
using type = array<V>;
};
template <typename... Ts>
struct binarify<std::tuple<Ts...>> {
using type = std::tuple<binarify_t<Ts>...>;
};
/// For reflectable struct, transform it recursively.
template <typename T>
requires (refl::reflectable_struct<T> && !is_directly_binarizable_v<T>)
struct binarify<T> : binarify<typename refl::member_types<T>::to_tuple> {};
/// A section in the binary data.
template <typename T>
struct Section {
/// Current count of elements.
uint32_t count = 0;
/// Total count of elements in the section.
uint32_t total = 0;
/// Offset of the section.
uint32_t offset = 0;
};
template <typename T>
struct layout;
/// Get the binary layout of a type. Make sure every type in the
/// layout is unique.
template <typename T>
using layout_t = tuple_uniuqe_t<typename layout<T>::type>;
template <typename T>
requires (is_directly_binarizable_v<T>)
struct layout<T> {
using type = std::tuple<>;
};
template <>
struct layout<std::string> {
using type = std::tuple<Section<char>>;
};
/// Every time we encounter a `std::vector<T>`, we will add a `section<T>`.
template <typename T>
struct layout<std::vector<T>> {
using type = decltype(std::tuple_cat(std::declval<std::tuple<Section<T>>>(),
std::declval<layout_t<T>>()));
};
template <typename... Ts>
struct layout<std::tuple<Ts...>> {
using type = decltype(std::tuple_cat(std::declval<layout_t<Ts>>()...));
};
/// For reflectable struct, recursively get the layout.
template <typename T>
requires (refl::reflectable_struct<T> && !is_directly_binarizable_v<T>)
struct layout<T> {
using type = layout_t<typename refl::member_types<T>::to_tuple>;
};
template <typename T>
struct Packer {
/// The layout of the binary data.
layout_t<T> layout = {};
/// The total size of the binary data.
uint32_t size = 0;
/// The buffer to store the binary data.
char* buffer = nullptr;
/// Recursively traverse the object and calculate the size of each section.
template <typename Object>
void init(const Object& object) {
if constexpr(std::same_as<Object, std::string>) {
std::get<Section<char>>(layout).total += object.size() + 1;
} else if constexpr(requires { typename Object::value_type; }) {
std::get<Section<typename Object::value_type>>(layout).total += object.size();
for(const auto& element: object) {
init(element);
}
} else if constexpr(refl::reflectable_struct<Object>) {
refl::foreach(object, [&](auto, auto& field) { init(field); });
}
}
/// Write the object to the buffer and return the binary representation.
template <typename Object>
auto write(const Object& object) {
if constexpr(is_directly_binarizable_v<Object> && !refl::reflectable_struct<Object>) {
return object;
} else if constexpr(std::same_as<Object, std::string>) {
auto& section = std::get<Section<char>>(layout);
uint32_t size = object.size();
uint32_t offset = section.offset + section.count;
section.count += size + 1;
std::memcpy(buffer + offset, object.data(), size);
buffer[offset + size] = '\0';
return string{offset, size};
} else if constexpr(requires { typename Object::value_type; }) {
using V = typename Object::value_type;
auto& section = std::get<Section<V>>(layout);
uint32_t size = object.size();
uint32_t offset = section.offset + section.count * sizeof(binarify_t<V>);
section.count += size;
for(std::size_t i = 0; i < size; ++i) {
::new (buffer + offset + i * sizeof(binarify_t<V>)) auto{write(object[i])};
}
return array<V>{offset, size};
} else if constexpr(refl::reflectable_struct<Object>) {
std::array<char, sizeof(binarify_t<Object>)> buffer;
std::memset(buffer.data(), 0, sizeof(buffer));
binarify_t<Object> result;
refl::foreach(result, object, [&](auto& lhs, auto& rhs) {
auto offset = reinterpret_cast<char*>(&lhs) - reinterpret_cast<char*>(&result);
::new (buffer.data() + offset) auto{write(rhs)};
});
return buffer;
} else {
static_assert(dependent_false<Object>, "Unsupported type.");
}
}
char* pack(const auto& object) {
/// First initialize the layout.
init(object);
/// Calculate the total size of the binary data and
/// the offset of each section.
size = sizeof(binarify_t<T>);
auto try_each = [&]<typename V>(auto, Section<V>& field) {
static_assert(alignof(binarify_t<V>) <= 8, "Alignment not supported.");
/// Make sure each section is aligned to 8 bytes.
if(size % 8 != 0) {
size += 8 - size % 8;
}
field.offset = size;
size += field.total * sizeof(binarify_t<V>);
};
refl::foreach(layout, try_each);
/// Allocate the buffer and write the data to the buffer.
buffer = static_cast<char*>(std::malloc(size));
/// Make sure the buffer is clean. So we can compare the result.
/// Every padding in the struct should be filled with 0.
std::memset(buffer, 0, size);
/// Write the object to the buffer.
auto result = write(object);
std::memcpy(buffer, &result, sizeof(result));
return buffer;
}
};
} // namespace impl
template <std::size_t N>
struct fixed_string : std::array<char, N + 1> {
template <std::size_t M>
constexpr fixed_string(const char (&str)[M]) {
for(std::size_t i = 0; i < N; ++i) {
this->data()[i] = str[i];
}
this->data()[N] = '\0';
}
constexpr auto size() const {
return N;
}
constexpr operator std::string_view () const {
return {this->data(), N};
}
};
template <std::size_t M>
fixed_string(const char (&)[M]) -> fixed_string<M - 1>;
/// A helper class to access the binary data.
template <typename T>
struct Proxy {
using underlying_type = impl::binarify_t<T>;
const void* base;
const void* data;
const auto& value() const {
return *reinterpret_cast<const underlying_type*>(data);
}
template <std::size_t I>
auto get() const {
return Proxy<refl::member_type<T, I>>{base, &std::get<I>(value())};
}
template <fixed_string name>
auto get() const {
constexpr auto& names = refl::member_names<T>();
constexpr auto index = []() {
for(std::size_t i = 0; i < names.size(); ++i) {
if(names[i] == name) {
return i;
}
}
return names.size();
}();
return this->template get<index>();
}
auto as_string() const {
auto [offset, size] = value();
return llvm::StringRef{reinterpret_cast<const char*>(base) + offset, size};
}
auto as_array() const {
auto [offset, size] = value();
using U = impl::binarify_t<typename T::value_type>;
return llvm::ArrayRef<U>{
reinterpret_cast<const U*>(static_cast<const char*>(base) + offset),
size,
};
}
auto operator[] (std::size_t index) const {
return Proxy<typename T::value_type>{base, &as_array()[index]};
}
auto size() const {
return value().size;
}
auto operator->() const {
return &value();
}
operator const underlying_type& () const {
return value();
}
};
/// Binirize an object.
template <typename Object>
std::pair<Proxy<Object>, size_t> binarify(const Object& object) {
impl::Packer<Object> packer;
auto buffer = packer.pack(object);
return {
Proxy<Object>{buffer, reinterpret_cast<const impl::binarify_t<Object>*>(buffer)},
packer.size
};
}
} // namespace clice::binary