mirror of
https://github.com/JakeHillion/object-introspection.git
synced 2024-09-19 19:19:05 +01:00
77 lines
2.4 KiB
C++
77 lines
2.4 KiB
C++
/*
|
|
* Copyright (c) Meta Platforms, Inc. and affiliates.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
#include <oi/exporters/ParsedData.h>
|
|
|
|
#include <cassert>
|
|
#include <stdexcept>
|
|
#include <type_traits>
|
|
|
|
template <typename T>
|
|
constexpr bool always_false_v = false;
|
|
|
|
namespace oi::exporters {
|
|
namespace {
|
|
uint64_t parseVarint(std::vector<uint8_t>::const_iterator& it);
|
|
}
|
|
|
|
ParsedData ParsedData::parse(std::vector<uint8_t>::const_iterator& it,
|
|
types::dy::Dynamic dy) {
|
|
return std::visit(
|
|
[&it](const auto el) -> ParsedData {
|
|
auto ty = el.get();
|
|
using T = std::decay_t<decltype(ty)>;
|
|
if constexpr (std::is_same_v<T, types::dy::Unit>) {
|
|
return ParsedData::Unit{};
|
|
} else if constexpr (std::is_same_v<T, types::dy::VarInt>) {
|
|
return ParsedData::VarInt{.value = parseVarint(it)};
|
|
} else if constexpr (std::is_same_v<T, types::dy::Pair>) {
|
|
return ParsedData::Pair{
|
|
.first = Lazy{it, ty.first},
|
|
.second = Lazy{it, ty.second},
|
|
};
|
|
} else if constexpr (std::is_same_v<T, types::dy::List>) {
|
|
return ParsedData::List{
|
|
.length = parseVarint(it),
|
|
.values = {it, ty.element},
|
|
};
|
|
} else if constexpr (std::is_same_v<T, types::dy::Sum>) {
|
|
auto index = parseVarint(it);
|
|
assert(index < ty.variants.size());
|
|
return ParsedData::Sum{
|
|
.index = index,
|
|
.value = {it, ty.variants[index]},
|
|
};
|
|
} else {
|
|
static_assert(always_false_v<T>, "non-exhaustive visitor!");
|
|
}
|
|
},
|
|
dy);
|
|
}
|
|
|
|
namespace {
|
|
uint64_t parseVarint(std::vector<uint8_t>::const_iterator& it) {
|
|
uint64_t v = 0;
|
|
int shift = 0;
|
|
while (*it >= 0x80) {
|
|
v |= static_cast<uint64_t>(*it++ & 0x7f) << shift;
|
|
shift += 7;
|
|
}
|
|
v |= static_cast<uint64_t>(*it++ & 0x7f) << shift;
|
|
return v;
|
|
}
|
|
} // namespace
|
|
} // namespace oi::exporters
|