byteorder.hh

/*
 * This file is open source software, licensed to you under the terms
 * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
 * distributed with this work for additional information regarding copyright
 * ownership.  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.
 */
/*
 * Copyright (C) 2014 Cloudius Systems, Ltd.
 */
 
#pragma once
 
#ifndef SEASTAR_MODULE
#include <arpa/inet.h>  // for ntohs() and friends
#include <iosfwd>
#include <utility>
#endif
 
#include <seastar/core/unaligned.hh>
#include <seastar/util/modules.hh>
 
namespace seastar {
 
inline uint64_t ntohq(uint64_t v) {
#if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
    // big endian, nothing to do
    return v;
#else
    // little endian, reverse bytes
    return __builtin_bswap64(v);
#endif
}
inline uint64_t htonq(uint64_t v) {
    // htonq and ntohq have identical implementations
    return ntohq(v);
}
 
namespace net {
 
inline void ntoh() {}
inline void hton() {}
 
inline uint8_t ntoh(uint8_t x) { return x; }
inline uint8_t hton(uint8_t x) { return x; }
inline uint16_t ntoh(uint16_t x) { return ntohs(x); }
inline uint16_t hton(uint16_t x) { return htons(x); }
inline uint32_t ntoh(uint32_t x) { return ntohl(x); }
inline uint32_t hton(uint32_t x) { return htonl(x); }
inline uint64_t ntoh(uint64_t x) { return ntohq(x); }
inline uint64_t hton(uint64_t x) { return htonq(x); }
 
inline int8_t ntoh(int8_t x) { return x; }
inline int8_t hton(int8_t x) { return x; }
inline int16_t ntoh(int16_t x) { return ntohs(x); }
inline int16_t hton(int16_t x) { return htons(x); }
inline int32_t ntoh(int32_t x) { return ntohl(x); }
inline int32_t hton(int32_t x) { return htonl(x); }
inline int64_t ntoh(int64_t x) { return ntohq(x); }
inline int64_t hton(int64_t x) { return htonq(x); }
 
// Deprecated alias net::packed<> for unaligned<> from unaligned.hh.
// TODO: get rid of this alias.
template <typename T> using packed = unaligned<T>;
 
template <typename T>
inline T ntoh(const packed<T>& x) {
    T v = x;
    return ntoh(v);
}
 
template <typename T>
inline T hton(const packed<T>& x) {
    T v = x;
    return hton(v);
}
 
template <typename T>
inline std::ostream& operator<<(std::ostream& os, const packed<T>& v) {
    auto x = v.raw;
    return os << x;
}
 
inline
void ntoh_inplace() {}
inline
void hton_inplace() {};
 
template <typename First, typename... Rest>
inline
void ntoh_inplace(First& first, Rest&... rest) {
    first = ntoh(first);
    ntoh_inplace(std::forward<Rest&>(rest)...);
}
 
template <typename First, typename... Rest>
inline
void hton_inplace(First& first, Rest&... rest) {
    first = hton(first);
    hton_inplace(std::forward<Rest&>(rest)...);
}
 
template <class T>
inline
T ntoh(const T& x) {
    T tmp = x;
    tmp.adjust_endianness([] (auto&&... what) { ntoh_inplace(std::forward<decltype(what)&>(what)...); });
    return tmp;
}
 
template <class T>
inline
T hton(const T& x) {
    T tmp = x;
    tmp.adjust_endianness([] (auto&&... what) { hton_inplace(std::forward<decltype(what)&>(what)...); });
    return tmp;
}
 
}
 
}