kendryte-standalone-sdk/lib/nncase/v0/include/runtime/span_reader.h

113 lines
2.8 KiB
C++

/* Copyright 2019-2020 Canaan Inc.
*
* 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.
*/
#pragma once
#include <xtl/xspan.hpp>
#include <cstring>
namespace nncase
{
namespace runtime
{
class span_reader
{
public:
span_reader(xtl::span<const uint8_t> span)
: span_(span)
{
}
bool empty() const noexcept { return span_.empty(); }
template <class T>
T read()
{
auto value = *reinterpret_cast<const T *>(span_.data());
advance(sizeof(T));
return value;
}
template <class T>
T read_unaligned()
{
T value;
std::memcpy(&value, span_.data(), sizeof(T));
advance(sizeof(T));
return value;
}
template <class T>
void read(T &value)
{
value = *reinterpret_cast<const T *>(span_.data());
advance(sizeof(T));
}
template <class T>
void read_span(xtl::span<const T> &span, size_t size)
{
span = { reinterpret_cast<const T *>(span_.data()), size };
advance(sizeof(T) * size);
}
template <class T, ptrdiff_t N>
void read_span(xtl::span<const T, N> &span)
{
span = { reinterpret_cast<const T *>(span_.data()), N };
advance(sizeof(T) * N);
}
void read_avail(xtl::span<const uint8_t> &span)
{
span = span_;
span_ = {};
}
template <class T>
const T *peek() const noexcept
{
return reinterpret_cast<const T *>(span_.data());
}
template <class T>
void get_array(const T *&value, size_t size)
{
value = peek<T>();
advance(size * sizeof(T));
}
template <class T>
void get_ref(const T *&value)
{
value = peek<T>();
advance(sizeof(T));
}
void skip(size_t count)
{
advance(count);
}
private:
void advance(size_t count)
{
span_ = span_.subspan(count);
}
private:
xtl::span<const uint8_t> span_;
};
}
}