ceph/src/seastar/include/seastar/core/byteorder.hh

   1 /*
   2  * This file is open source software, licensed to you under the terms
   3  * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
   4  * distributed with this work for additional information regarding copyright
   5  * ownership.  You may not use this file except in compliance with the License.
   6  *
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing,
  12  * software distributed under the License is distributed on an
  13  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  14  * KIND, either express or implied.  See the License for the
  15  * specific language governing permissions and limitations
  16  * under the License.
  17  */
  18 /*
  19  * Copyright (C) 2015 Scylladb, Ltd.
  20  */
  21
  22 #pragma once
  23
  24 #include <algorithm>
  25 #include <boost/endian/conversion.hpp>
  26 #include <seastar/core/unaligned.hh>
  27
  28 namespace seastar {
  29
  30 template <typename T>
  31 inline T cpu_to_le(T x) noexcept {
  32   return boost::endian::native_to_little(x);
  33 }
  34 template <typename T>
  35 inline T le_to_cpu(T x) noexcept {
  36   return boost::endian::little_to_native(x);
  37 }
  38
  39 template <typename T>
  40 inline T cpu_to_be(T x) noexcept {
  41   return boost::endian::native_to_big(x);
  42 }
  43 template <typename T>
  44 inline T be_to_cpu(T x) noexcept {
  45   return boost::endian::big_to_native(x);
  46 }
  47
  48 template <typename T>
  49 inline T cpu_to_le(const unaligned<T>& v) noexcept {
  50     return cpu_to_le(T(v));
  51 }
  52
  53 template <typename T>
  54 inline T le_to_cpu(const unaligned<T>& v) noexcept {
  55     return le_to_cpu(T(v));
  56 }
  57
  58 template <typename T>
  59 inline
  60 T
  61 read_le(const char* p) noexcept {
  62     T datum;
  63     std::copy_n(p, sizeof(T), reinterpret_cast<char*>(&datum));
  64     return le_to_cpu(datum);
  65 }
  66
  67 template <typename T>
  68 inline
  69 void
  70 write_le(char* p, T datum) noexcept {
  71     datum = cpu_to_le(datum);
  72     std::copy_n(reinterpret_cast<const char*>(&datum), sizeof(T), p);
  73 }
  74
  75 template <typename T>
  76 inline
  77 T
  78 read_be(const char* p) noexcept {
  79     T datum;
  80     std::copy_n(p, sizeof(T), reinterpret_cast<char*>(&datum));
  81     return be_to_cpu(datum);
  82 }
  83
  84 template <typename T>
  85 inline
  86 void
  87 write_be(char* p, T datum) noexcept {
  88     datum = cpu_to_be(datum);
  89     std::copy_n(reinterpret_cast<const char*>(&datum), sizeof(T), p);
  90 }
  91
  92 template <typename T>
  93 inline
  94 T
  95 consume_be(const char*& p) noexcept {
  96     auto ret = read_be<T>(p);
  97     p += sizeof(T);
  98     return ret;
  99 }
 100
 101 template <typename T>
 102 inline
 103 void
 104 produce_be(char*& p, T datum) noexcept {
 105     write_be<T>(p, datum);
 106     p += sizeof(T);
 107 }
 108
 109 }