General Purpose library for Freestanding C++ and POSIX systems
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#pragma once
#include <gp/algorithms/repeat.hpp>
#include <gp/math/boolean/bitops.hpp>
#include <gp/functional/optional.hpp>
#include <gp/utils/pair.hpp>
#include <gp/functional/variant.hpp>
#include <gp/containers/vector.hpp>
#include <concepts>
// TODO: Rewrite in a more ORM-like way
// TODO: Implement some bignum for support
namespace gp {
enum class cbor_type : uint8_t {
uint = 0,
nint = 1,
bstr = 2,
tstr = 3,
list = 4,
hmap = 5,
tags = 6,
oths = 7
};
enum class cbor_oths : uint8_t {
value_false = 20,
value_true = 21,
value_null = 22,
value_undefined = 23,
byte = 24,
word = 25,
dword = 26,
qword = 27,
terminator = 31
};
struct cbor_number final {
bool sign;
uint64_t value;
bool is_negative() {
return sign;
}
cbor_number(int64_t v)
: sign{v < 0}
, value{uint64_t((sign ? -1 : 1) * v)}
{}
cbor_number(bool s, uint64_t v)
: sign{s}
, value{v}
{}
};
struct ieee754_hf final {
uint16_t sign : 1;
uint16_t exponent : 5;
uint16_t mantissa : 10;
// TODO: support for denormalized values and NaNs
operator float() {
auto a = (uint32_t)((sign<<16) | ((exponent+0x1C000)<<13) | (mantissa<<13));
return *(float*)&a;
}
operator double() {
return (float)*this;
}
};
inline vector<char>& push_integer_with_header_as_cbor(vector<char>& src, uint8_t header, uint64_t value) {
auto norm_v = (value<0) ? -value : value;
if(norm_v <= 23) {
src.push_back(header+norm_v);
} else if(norm_v < (1ll<<8ll)) {
src.push_back(header+24);
src.push_back(norm_v);
} else if(norm_v < (1ll<<16ll)) {
endian_wrapper<uint16_t, endian::big> wrapper = norm_v;
src.push_back(header+25);
for(auto byte : wrapper.bytes()) {
src.push_back(byte);
}
} else if(norm_v < (1ll<<32ll)) {
endian_wrapper<uint32_t, endian::big> wrapper = norm_v;
src.push_back(header+26);
for(auto byte : wrapper.bytes()) {
src.push_back(byte);
}
} else {
endian_wrapper<uint64_t, endian::big> wrapper = norm_v;
src.push_back(header+27);
for(auto byte : wrapper.bytes()) {
src.push_back(byte);
}
}
return src;
}
/**
* @brief Pushes an integer as CBOR on the vector
*
* @param src the vector on which the push happens
* @param value the value to push, can be signed
* @return vector<char>& the same reference that was received for the source
*/
template<std::signed_integral T>
inline vector<char>& push_as_cbor(vector<char>& src, T value) {
uint8_t sign = (value<0) ? 0b00100000 : 0;
auto norm_v = (value<0) ? -value : value;
return push_integer_with_header_as_cbor(src, sign, norm_v);
}
/**
* @brief Pushes an unsigned integer as CBOR on the vector
*
* @param src the vector on which the push happens
* @param value the value to push, cannot be signed
* @return vector<char>& the same reference that was received for the source
*/
template<std::unsigned_integral T>
inline vector<char>& push_as_cbor(vector<char>& src, T value) {
return push_integer_with_header_as_cbor(src, 0, value);
}
inline vector<char>& push_as_cbor(vector<char>& src, std::nullptr_t) {
src.push_back(0b11110110);
return src;
}
struct cbor_undefined{};
inline vector<char>& push_as_cbor(vector<char>& src, cbor_undefined) {
src.push_back(0b11110111);
return src;
}
inline vector<char>& push_as_cbor(vector<char>& src, bool value) {
src.push_back(0b11110100+(value ? 1 : 0));
return src;
}
inline vector<char>& push_as_cbor(vector<char>& src, gp::buffer<char> value) {
push_integer_with_header_as_cbor(src, (uint8_t)0b01000000, value.size());
for(auto byte : value) {
src.push_back(byte);
}
return src;
}
struct cbor_array_initiator {
size_t size;
};
struct cbor_associative_array_initiator {
size_t size;
};
inline vector<char>& push_as_cbor(vector<char>& src, cbor_array_initiator value) {
return push_integer_with_header_as_cbor(src, (uint8_t)0b10000000, value.size);
}
inline vector<char>& push_as_cbor(vector<char>& src, cbor_associative_array_initiator value) {
return push_integer_with_header_as_cbor(src, (uint8_t)0b10100000, value.size);
}
template<typename First, typename Second>
inline vector<char>& push_as_cbor(vector<char>& src, gp::pair<First, Second> value) {
push_as_cbor(src,value.first);
return push_as_cbor(src,value.second);
}
template<typename First, typename Second>
inline vector<char>& push_as_cbor(vector<char>& src, gp::pair<First, Second>& value) {
push_as_cbor(src,value.first);
return push_as_cbor(src,value.second);
}
struct cbor_tag_initiator {
union {
size_t as_integer;
gp_config::cbor_tag tag;
};
};
inline vector<char>& push_as_cbor(vector<char>& src, cbor_tag_initiator value) {
return push_integer_with_header_as_cbor(src, (uint8_t)0b11000000, value.as_integer);
}
using parsing_state = gp::buffer<char>;
template<typename T>
gp::pair<gp::optional<T>, parsing_state> read_cbor(parsing_state state, gp::allocator&);
inline gp::pair<gp::optional<uint64_t>, parsing_state> pull_arbitrary_integer_from_cbor(parsing_state state) {
auto local = (uint8_t)0b00011111 & (uint8_t)*state.begin();
if(local <= 23) {
return {local, {state.begin()+1, state.end()}};
} else {
switch((cbor_oths)local) {
case cbor_oths::byte: {
if(state.size() < 2) return {nullopt, state};
return {*(state.begin()+1), {state.begin()+2, state.end()}};
}
case cbor_oths::word: {
if(state.size() < 3) return {nullopt, state};
return {
uint16_t(*(state.slice_start(3).slice_end(2).cast<gp::endian_wrapper<uint16_t, endian::big>>().begin())),
{state.begin()+3, state.end()}
};
}
case cbor_oths::dword: {
if(state.size() < 5) return {nullopt, state};
return {
uint32_t(*(state.slice_start(5).slice_end(4).cast<gp::endian_wrapper<uint32_t, endian::big>>().begin())),
{state.begin()+5, state.end()}
};
}
case cbor_oths::qword: {
if(state.size() < 9) return {nullopt, state};
return {
uint64_t(*(state.slice_start(9).slice_end(8).cast<gp::endian_wrapper<uint64_t, endian::big>>().begin())),
{state.begin()+9, state.end()}
};
}
default: {
return {nullopt, state};
}
}
}
}
template<std::integral T>
inline gp::pair<gp::optional<T>, parsing_state> read_cbor(parsing_state state, gp::allocator&) {
// TODO: Handling of over and underflow
if(!state.size()) return {nullopt, state};
auto type = cbor_type(((uint8_t)0b11100000 & (uint8_t)*state.begin()) >> 5);
switch(type) {
case cbor_type::uint:
{
auto[value, new_state] = pull_arbitrary_integer_from_cbor(state);
if(value.has_value()) return {value.value(), new_state};
break;
}
case cbor_type::nint:
{
auto[value, new_state] = pull_arbitrary_integer_from_cbor(state);
if(value.has_value()) return {-value.value(), new_state};
break;
}
default:
break;
}
return {nullopt, state};
}
template<>
inline gp::pair<gp::optional<cbor_tag_initiator>, parsing_state> read_cbor<cbor_tag_initiator>(parsing_state state, gp::allocator&) {
if(!state.size()) return {nullopt, state};
auto type = cbor_type(((uint8_t)0b11100000 & (uint8_t)*state.begin()) >> 5);
switch(type) {
case cbor_type::tags:
{
auto[value, new_state] = pull_arbitrary_integer_from_cbor(state);
if(value.has_value()) return {cbor_tag_initiator{.as_integer = value.value()}, new_state};
break;
}
default: break;
}
return {nullopt, state};
}
template<>
inline gp::pair<gp::optional<gp::vector<char>>, parsing_state> read_cbor<gp::vector<char>>(parsing_state state, gp::allocator& alloc) {
if(!state.size()) return {nullopt, state};
auto type = cbor_type(((uint8_t)0b11100000 & (uint8_t)*state.begin()) >> 5);
switch(type) {
case cbor_type::bstr:
{
const auto[size, new_state] = pull_arbitrary_integer_from_cbor(state);
if(!size.has_value()) break;
if(new_state.size()<size.value()) break;
gp::vector<char> return_value{alloc};
if(!return_value.reserve(size.value())) break;
auto end_it = new_state.begin() + size.value();
for(auto it = new_state.begin(); it != end_it; it++) {
return_value.push_back(*it);
}
return {return_value, parsing_state(new_state.begin() + size.value(), new_state.end())};
break;
}
default: break;
}
return {nullopt, state};
}
template<>
inline gp::pair<gp::optional<std::nullptr_t>, parsing_state> read_cbor<std::nullptr_t>(parsing_state state, gp::allocator& alloc) {
if(!state.size()) return {nullopt, state};
auto type = cbor_type(((uint8_t)0b11100000 & (uint8_t)*state.begin()) >> 5);
switch(type) {
case cbor_type::oths:
{
const auto[value, new_state] = pull_arbitrary_integer_from_cbor(state);
if(!value.has_value()) break;
if(value.value() == 22)
{
return {optional(nullptr), parsing_state(new_state.begin()+1, new_state.end())};
}
break;
}
default: break;
}
return {nullopt, state};
}
template<>
inline gp::pair<gp::optional<bool>, parsing_state> read_cbor<bool>(parsing_state state, gp::allocator& alloc) {
if(!state.size()) return {nullopt, state};
auto type = cbor_type(((uint8_t)0b11100000 & (uint8_t)*state.begin()) >> 5);
switch(type) {
case cbor_type::oths:
{
const auto[value, new_state] = pull_arbitrary_integer_from_cbor(state);
if(!value.has_value()) break;
if(value.value() == 20)
{
return {false, parsing_state(new_state.begin()+1, new_state.end())};
}
else if(value.value() == 21)
{
return {true, parsing_state(new_state.begin()+1, new_state.end())};
}
break;
}
default: break;
}
return {nullopt, state};
}
template<>
inline gp::pair<gp::optional<cbor_undefined>, parsing_state> read_cbor<cbor_undefined>(parsing_state state, gp::allocator& alloc) {
if(!state.size()) return {nullopt, state};
auto type = cbor_type(((uint8_t)0b11100000 & (uint8_t)*state.begin()) >> 5);
switch(type) {
case cbor_type::oths:
{
const auto[value, new_state] = pull_arbitrary_integer_from_cbor(state);
if(!value.has_value()) break;
if(value.value() == 23)
{
return {optional(cbor_undefined{}), parsing_state(new_state.begin()+1, new_state.end())};
}
break;
}
default: break;
}
return {nullopt, state};
}
/**
* @brief
*
* @param state
* @param callback a callback that returns a new parsing state for every element read. It should follow the heredescribed signature: parsing_state(parsing_state, gp::allocator&)
* @param count_callback a callback that is used to check if the process should proceed given a count of elements in the list. It should follow the heredescribed signature: bool(uint64_t)
* @param alloc
*/
template<typename applier_cb, typename counter_cb>
inline parsing_state read_cbor_array(parsing_state state, gp::allocator& alloc, applier_cb callback, counter_cb count_callback = [](uint64_t) -> bool {return true;}) {
if(!state.size()) return state;
auto type = cbor_type(((uint8_t)0b11100000 & (uint8_t)*state.begin()) >> 5);
switch(type) {
case cbor_type::list:
{
const auto[size, new_state] = pull_arbitrary_integer_from_cbor(state);
if(!size.has_value()) return state;
if(new_state.size()<size.value()) return state;
if(!count_callback(size.value()))return state;
parsing_state forward = new_state;
for(auto idx = 0ull; idx != size.value(); idx++) {
if(forward.size() == 0) return state;
forward = callback(forward, alloc);
}
return forward;
}
default: return state;
}
}
/**
* @brief
*
* @param state
* @param callback a callback that returns a new parsing state for every element read. It should follow the heredescribed signature: parsing_state(parsing_state, gp::allocator&), it MUST read exactly 2 cbor value from the stream.
* @param count_callback a callback that is used to check if the process should proceed given a count of elements in the list. It should follow the heredescribed signature: bool(uint64_t)
* @param alloc
*/
template<typename applier_cb, typename counter_cb>
inline parsing_state read_cbor_kv_list(parsing_state state, gp::allocator& alloc, applier_cb callback, counter_cb count_callback = [](uint64_t) -> bool {return true;}) {
if(!state.size()) return state;
auto type = cbor_type(((uint8_t)0b11100000 & (uint8_t)*state.begin()) >> 5);
switch(type) {
case cbor_type::hmap:
{
const auto[size, new_state] = pull_arbitrary_integer_from_cbor(state);
if(!size.has_value()) return state;
if(!count_callback(size.value()))return state;
parsing_state forward = new_state;
for(auto idx = 0ull; idx != size.value(); idx++) {
if(forward.size() < 2ull) return state;
forward = callback(forward, alloc);
forward = callback(forward, alloc);
}
return forward;
}
default: return state;
}
}
}