lokinet/llarp/util/aligned.hpp
Jason Rhinelander d4a5dc66ac Change alignment to std::max_align_t
This will typically be stricter alignment (16 byte on amd64) which seems
useful for the intended use case here.
2019-12-12 12:15:13 -04:00

276 lines
4.7 KiB
C++

#ifndef LLARP_ALIGNED_HPP
#define LLARP_ALIGNED_HPP
#include <util/bencode.h>
#include <util/encode.hpp>
#include <util/logging/logger.hpp>
#include <util/meta/traits.hpp>
#include <util/printer.hpp>
#include <array>
#include <cstddef>
#include <iomanip>
#include <iostream>
#include <memory>
#include <numeric>
#include <type_traits>
#include <algorithm>
extern "C"
{
extern void
randombytes(unsigned char* const ptr, unsigned long long sz);
extern int
sodium_is_zero(const unsigned char *n, const size_t nlen);
}
namespace llarp
{
/// aligned buffer that is sz bytes long and aligns to the nearest Alignment
template < size_t sz >
struct alignas(std::max_align_t) AlignedBuffer
{
static constexpr size_t SIZE = sz;
using Data = std::array< byte_t, SIZE >;
AlignedBuffer()
{
Zero();
}
explicit AlignedBuffer(const byte_t* data)
{
*this = data;
}
explicit AlignedBuffer(const Data& buf)
{
m_data = buf;
}
AlignedBuffer&
operator=(const byte_t* data)
{
std::memcpy(m_data.data(), data, sz);
return *this;
}
friend std::ostream&
operator<<(std::ostream& out, const AlignedBuffer& self)
{
char tmp[(sz * 2) + 1] = {0};
return out << HexEncode(self, tmp);
}
/// bitwise NOT
AlignedBuffer< sz >
operator~() const
{
AlignedBuffer< sz > ret;
std::transform(begin(), end(), ret.begin(), [](byte_t a) { return ~a; });
return ret;
}
bool
operator==(const AlignedBuffer& other) const
{
return m_data == other.m_data;
}
bool
operator!=(const AlignedBuffer& other) const
{
return m_data != other.m_data;
}
bool
operator<(const AlignedBuffer& other) const
{
return m_data < other.m_data;
}
bool
operator>(const AlignedBuffer& other) const
{
return m_data > other.m_data;
}
bool
operator<=(const AlignedBuffer& other) const
{
return m_data <= other.m_data;
}
bool
operator>=(const AlignedBuffer& other) const
{
return m_data >= other.m_data;
}
AlignedBuffer
operator^(const AlignedBuffer& other) const
{
AlignedBuffer< sz > ret;
std::transform(begin(), end(), other.begin(), ret.begin(),
std::bit_xor< byte_t >());
return ret;
}
AlignedBuffer&
operator^=(const AlignedBuffer& other)
{
// Mutate in place instead.
for(size_t i = 0; i < sz; ++i)
{
m_data[i] ^= other.m_data[i];
}
return *this;
}
byte_t& operator[](size_t idx)
{
assert(idx < SIZE);
return m_data[idx];
}
const byte_t& operator[](size_t idx) const
{
assert(idx < SIZE);
return m_data[idx];
}
static constexpr size_t
size()
{
return sz;
}
void
Fill(byte_t f)
{
m_data.fill(f);
}
Data&
as_array()
{
return m_data;
}
const Data&
as_array() const
{
return m_data;
}
byte_t*
data()
{
return m_data.data();
}
const byte_t*
data() const
{
return m_data.data();
}
bool
IsZero() const
{
return sodium_is_zero(data(), size());
}
void
Zero()
{
m_data.fill(0);
}
void
Randomize()
{
randombytes(data(), SIZE);
}
typename Data::iterator
begin()
{
return m_data.begin();
}
typename Data::iterator
end()
{
return m_data.end();
}
typename Data::const_iterator
begin() const
{
return m_data.cbegin();
}
typename Data::const_iterator
end() const
{
return m_data.cend();
}
bool
BEncode(llarp_buffer_t* buf) const
{
return bencode_write_bytestring(buf, data(), sz);
}
bool
BDecode(llarp_buffer_t* buf)
{
llarp_buffer_t strbuf;
if(!bencode_read_string(buf, &strbuf))
{
return false;
}
if(strbuf.sz != sz)
{
llarp::LogError("bdecode buffer size missmatch ", strbuf.sz, "!=", sz);
return false;
}
memcpy(data(), strbuf.base, sz);
return true;
}
std::string
ToHex() const
{
char strbuf[(1 + sz) * 2] = {0};
return std::string(HexEncode(*this, strbuf));
}
std::ostream&
print(std::ostream& stream, int level, int spaces) const
{
Printer printer(stream, level, spaces);
printer.printValue(ToHex());
return stream;
}
struct Hash
{
size_t
operator()(const AlignedBuffer& buf) const
{
return *(reinterpret_cast< const size_t* >(buf.data()));
}
};
private:
Data m_data;
};
} // namespace llarp
#endif