src/cpp-common/uuid.hpp

   1 /*
   2  * Copyright (c) 2022 Francis Deslauriers <francis.deslauriers@efficios.com>
   3  *
   4  * SPDX-License-Identifier: MIT
   5  */
   6
   7 #ifndef BABELTRACE_CPP_COMMON_UUID_HPP
   8 #define BABELTRACE_CPP_COMMON_UUID_HPP
   9
  10 #include <algorithm>
  11 #include <array>
  12 #include <cstdint>
  13 #include <string>
  14
  15 #include "common/assert.h"
  16 #include "common/uuid.h"
  17 #include "uuid-view.hpp"
  18
  19 namespace bt2_common {
  20
  21 /*
  22  * A universally unique identifier.
  23  *
  24  * A `Uuid` object contains its UUID data: see `UuidView` to have a
  25  * UUID view on existing UUID data.
  26  */
  27 class Uuid final
  28 {
  29 public:
  30     using Val = UuidView::Val;
  31     using ConstIter = UuidView::ConstIter;
  32
  33 public:
  34     /*
  35      * Builds a nil UUID.
  36      */
  37     explicit Uuid() noexcept = default;
  38
  39     explicit Uuid(const Val * const uuid) noexcept
  40     {
  41         this->_setFromPtr(uuid);
  42     }
  43
  44     explicit Uuid(const char * const str) noexcept
  45     {
  46         const auto ret = bt_uuid_from_str(str, _mUuid.data());
  47         BT_ASSERT(ret == 0);
  48     }
  49
  50     explicit Uuid(const std::string& str) noexcept : Uuid {str.c_str()}
  51     {
  52     }
  53
  54     explicit Uuid(const UuidView& view) noexcept : Uuid {view.data()}
  55     {
  56     }
  57
  58     Uuid(const Uuid&) noexcept = default;
  59     Uuid& operator=(const Uuid&) noexcept = default;
  60
  61     Uuid& operator=(const Val * const uuid) noexcept
  62     {
  63         this->_setFromPtr(uuid);
  64         return *this;
  65     }
  66
  67     static Uuid generate() noexcept
  68     {
  69         bt_uuid_t uuidGen;
  70
  71         bt_uuid_generate(uuidGen);
  72         return Uuid {uuidGen};
  73     }
  74
  75     std::string str() const
  76     {
  77         return this->_view().str();
  78     }
  79
  80     bool operator==(const Uuid& other) const noexcept
  81     {
  82         return this->_view() == other._view();
  83     }
  84
  85     bool operator!=(const Uuid& other) const noexcept
  86     {
  87         return this->_view() != other._view();
  88     }
  89
  90     bool operator<(const Uuid& other) const noexcept
  91     {
  92         return this->_view() < other._view();
  93     }
  94
  95     /*
  96      * The returned UUID view must not outlive the UUID object.
  97      */
  98     operator UuidView() const noexcept
  99     {
 100         return this->_view();
 101     }
 102
 103     static constexpr std::size_t size() noexcept
 104     {
 105         return UuidView::size();
 106     }
 107
 108     const Val *data() const noexcept
 109     {
 110         return _mUuid.data();
 111     }
 112
 113     Val operator[](const std::size_t index) const noexcept
 114     {
 115         return this->_view()[index];
 116     }
 117
 118     ConstIter begin() const noexcept
 119     {
 120         return this->_view().begin();
 121     }
 122
 123     ConstIter end() const noexcept
 124     {
 125         return this->_view().end();
 126     }
 127
 128     bool isNil() const noexcept
 129     {
 130         return this->_view().isNil();
 131     }
 132
 133 private:
 134     /*
 135      * std::copy_n() won't throw when simply copying bytes below,
 136      * therefore this method won't throw.
 137      */
 138     void _setFromPtr(const Val * const uuid) noexcept
 139     {
 140         BT_ASSERT(uuid);
 141         std::copy_n(uuid, BT_UUID_LEN, std::begin(_mUuid));
 142     }
 143
 144     UuidView _view() const noexcept
 145     {
 146         return UuidView {_mUuid.data()};
 147     }
 148
 149     std::array<Val, UuidView::size()> _mUuid = {};
 150 };
 151
 152 } /* namespace bt2_common */
 153
 154 #endif /* BABELTRACE_CPP_COMMON_UUID_HPP */