From 9d606695884bb73eb0dbdd9a176e4f07433e2259 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Wed, 24 Apr 2024 19:39:54 +0300
Subject: [PATCH] Add uuid::time_point_v1(), uuid_clock::from_timestamp,
 uuid_clock::to_timestamp

---
 include/boost/uuid/uuid.hpp       | 18 ++++++++++++++++++
 include/boost/uuid/uuid_clock.hpp | 13 +++++++++++++
 test/test_time_generator_v1.cpp   | 10 +---------
 test/test_uuid_clock.cpp          |  7 +++++--
 4 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/include/boost/uuid/uuid.hpp b/include/boost/uuid/uuid.hpp
index c191df3..c962e8d 100644
--- a/include/boost/uuid/uuid.hpp
+++ b/include/boost/uuid/uuid.hpp
@@ -33,6 +33,7 @@
 //  02 Dec 2009 - removed BOOST_STATIC_CONSTANT - not all compilers like it
 //  29 Apr 2013 - added support for noexcept and constexpr, added optimizations for SSE/AVX
 
+#include <boost/uuid/uuid_clock.hpp>
 #include <boost/uuid/detail/endian.hpp>
 #include <boost/uuid/detail/hash_mix.hpp>
 #include <boost/uuid/detail/config.hpp>
@@ -81,6 +82,8 @@ public:
 
     // accessors
 
+    // variant
+
     enum variant_type
     {
         variant_ncs, // NCS backward compatibility
@@ -106,6 +109,8 @@ public:
         }
     }
 
+    // version
+
     enum version_type
     {
         version_unknown = -1,
@@ -136,6 +141,8 @@ public:
         }
     }
 
+    // timestamp
+
     using timestamp_type = std::uint64_t;
 
     timestamp_type timestamp_v1() const BOOST_NOEXCEPT
@@ -147,6 +154,15 @@ public:
         return time_low | static_cast<std::uint64_t>( time_mid ) << 32 | static_cast<std::uint64_t>( time_hi ) << 48;
     }
 
+    // time_point
+
+    uuid_clock::time_point time_point_v1() const BOOST_NOEXCEPT
+    {
+        return uuid_clock::from_timestamp( timestamp_v1() );
+    }
+
+    // clock_seq
+
     using clock_seq_type = std::uint16_t;
 
     clock_seq_type clock_seq() const BOOST_NOEXCEPT
@@ -154,6 +170,8 @@ public:
         return detail::load_big_u16( this->data + 8 ) & 0x3FFF;
     }
 
+    // node_identifier
+
     using node_type = std::array<std::uint8_t, 6>;
 
     node_type node_identifier() const BOOST_NOEXCEPT
diff --git a/include/boost/uuid/uuid_clock.hpp b/include/boost/uuid/uuid_clock.hpp
index 0fdf081..0ee2700 100644
--- a/include/boost/uuid/uuid_clock.hpp
+++ b/include/boost/uuid/uuid_clock.hpp
@@ -27,6 +27,9 @@ public:
 
     static time_point from_sys( std::chrono::system_clock::time_point const& tp ) noexcept;
     static std::chrono::system_clock::time_point to_sys( time_point const& tp ) noexcept;
+
+    static time_point from_timestamp( std::uint64_t timestamp ) noexcept;
+    static std::uint64_t to_timestamp( time_point const& tp ) noexcept;
 };
 
 inline uuid_clock::time_point uuid_clock::now() noexcept
@@ -54,6 +57,16 @@ inline std::chrono::system_clock::time_point uuid_clock::to_sys( time_point cons
     return std::chrono::system_clock::time_point( sys_since );
 }
 
+inline uuid_clock::time_point uuid_clock::from_timestamp( std::uint64_t timestamp ) noexcept
+{
+    return time_point( duration( timestamp ) );
+}
+
+inline std::uint64_t uuid_clock::to_timestamp( time_point const& tp ) noexcept
+{
+    return tp.time_since_epoch().count();
+}
+
 } // uuids
 } // boost
 
diff --git a/test/test_time_generator_v1.cpp b/test/test_time_generator_v1.cpp
index dc662ec..4a313d4 100644
--- a/test/test_time_generator_v1.cpp
+++ b/test/test_time_generator_v1.cpp
@@ -13,14 +13,6 @@
 
 using namespace boost::uuids;
 
-uuid_clock::time_point get_time_point_v1( uuid const& u )
-{
-    auto t = u.timestamp_v1();
-    auto d = uuid_clock::duration( t );
-
-    return uuid_clock::time_point( d );
-}
-
 uuid generate_and_test( time_generator_v1& gen )
 {
     auto sys_before = std::chrono::time_point_cast<uuid_clock::duration>( std::chrono::system_clock::now() );
@@ -32,7 +24,7 @@ uuid generate_and_test( time_generator_v1& gen )
 
     auto sys_after = std::chrono::time_point_cast<uuid_clock::duration>( std::chrono::system_clock::now() );
 
-    auto uuid_time_point = get_time_point_v1( u );
+    auto uuid_time_point = u.time_point_v1();
 
     auto sys_time_point = uuid_clock::to_sys( uuid_time_point );
 
diff --git a/test/test_uuid_clock.cpp b/test/test_uuid_clock.cpp
index 818cb2d..a072faf 100644
--- a/test/test_uuid_clock.cpp
+++ b/test/test_uuid_clock.cpp
@@ -16,7 +16,9 @@ int main()
 
     std::uint64_t uuid_timestamp = 0x1ef018cddaa7790;
 
-    auto uuid_time = uuid_clock::time_point( uuid_clock::duration( uuid_timestamp ) );
+    auto uuid_time = uuid_clock::from_timestamp( uuid_timestamp );
+
+    BOOST_TEST_EQ( uuid_clock::to_timestamp( uuid_time ), uuid_timestamp );
 
     auto sys_time = uuid_clock::to_sys( uuid_time );
 
@@ -26,7 +28,8 @@ int main()
 
     auto uuid_time_2 = uuid_clock::from_sys( sys_time );
 
-    BOOST_TEST_EQ( uuid_time_2.time_since_epoch().count(), uuid_timestamp );
+    BOOST_TEST( uuid_time == uuid_time_2 );
+    BOOST_TEST_EQ( uuid_clock::to_timestamp( uuid_time_2 ), uuid_timestamp );
 
     return boost::report_errors();
 }