revert UUIDv1 construction

Doc/whatsnew/3.14.rst

@@ -675,18 +675,14 @@ uuid
 * Improve generation of :class:`~uuid.UUID` objects via their dedicated
   functions:
 
-  * For a given 48-bit hardware address *node* and a given 14-bit
-    clock sequence *clock_seq*, :func:`uuid1(node=node) <uuid.uuid1>`
-    and :func:`uuid1(clock_seq=clock_seq) <uuid.uuid1>` are 35% faster.
-    Performances for :func:`~uuid.uuid1` remain unchanged when neither
-    the hardware address nor the clock sequence is specified.
-  * :func:`~uuid.uuid3` is 27% faster for 16-byte names and 8% faster
+  * :func:`~uuid.uuid3` is 40% faster for 16-byte names and 10% faster
     for 1024-byte names. Performances for longer names remain unchanged.
-  * :func:`~uuid.uuid5` is 24% faster for 16-byte names and 11% faster
+  * :func:`~uuid.uuid5` is 38% faster for 16-byte names and 21% faster
     for 1024-byte names. Performances for longer names remain unchanged.
-  * :func:`~uuid.uuid4` and :func:`~uuid.uuid8` are 20% faster.
+  * :func:`~uuid.uuid4` is 31% faster and :func:`~uuid.uuid8` is 37% faster.
 
-  Overall, dedicated generation of UUID objects is 20% faster.
+  Overall, dedicated generation of UUID objects version 3, 4, 5, and 8 is
+  roughly 30% faster.
 
   (Contributed by Bénédikt Tran in :gh:`128150`.)
 

Lib/uuid.py

@@ -710,14 +710,12 @@ def uuid1(node=None, clock_seq=None):
     time_low = timestamp & 0xffffffff
     time_mid = (timestamp >> 32) & 0xffff
     time_hi_version = (timestamp >> 48) & 0x0fff
+    clock_seq_low = clock_seq & 0xff
+    clock_seq_hi_variant = (clock_seq >> 8) & 0x3f
     if node is None:
         node = getnode()
-    clock_seq = clock_seq & 0x3fff
-    int_uuid_1 = ((time_low << 96) | (time_mid << 80) |
-                  (time_hi_version << 64) | (clock_seq << 48) | node)
-    # by construction, the variant and version bits are already cleared
-    int_uuid_1 |= _RFC_4122_VERSION_1_FLAGS
-    return UUID(int=int_uuid_1, version=None)
+    return UUID(fields=(time_low, time_mid, time_hi_version,
+                        clock_seq_hi_variant, clock_seq_low, node), version=1)
 
 def uuid3(namespace, name):
     """Generate a UUID from the MD5 hash of a namespace UUID and a name."""

Misc/NEWS.d/next/Library/2024-12-21-11-12-50.gh-issue-128151.aq7vpG.rst

@@ -1,2 +1,2 @@
-Improve generation of :class:`~uuid.UUID` objects via their dedicated
-functions by 20%. Patch by Bénédikt Tran.
+Improve generation of :class:`~uuid.UUID` objects version 3, 4, 5, and 8
+via their dedicated functions by 30%. Patch by Bénédikt Tran.