Add optional node parameter to uuid6() (#109)

Author: oittaa

README.md

@@ -52,9 +52,9 @@ If your use case requires greater granularity than UUID version 7 can provide, y
 
 Generate a UUID version 6 object from a UUID version 1 object.
 
-### uuid6.uuid6(*clock_seq=None*)
+### uuid6.uuid6(*node=None*, *clock_seq=None*)
 
-Generate a UUID from a random number, sequence number, and the current time. If *clock_seq* is given, it is used as the sequence number; otherwise a random 14-bit sequence number is chosen.
+Generate a UUID from a host ID, sequence number, and the current time. If *node* is not given, a random 48-bit number is chosen. If *clock_seq* is given, it is used as the sequence number; otherwise a random 14-bit sequence number is chosen.
 
 ### uuid6.uuid7()
 

src/uuid6/__init__.py

@@ -92,12 +92,14 @@ def uuid1_to_uuid6(uuid1: uuid.UUID) -> UUID:
 _last_v8_timestamp = None
 
 
-def uuid6(clock_seq: Optional[int] = None) -> UUID:
+def uuid6(node: Optional[int] = None, clock_seq: Optional[int] = None) -> UUID:
     r"""UUID version 6 is a field-compatible version of UUIDv1, reordered for
     improved DB locality. It is expected that UUIDv6 will primarily be
     used in contexts where there are existing v1 UUIDs. Systems that do
     not involve legacy UUIDv1 SHOULD consider using UUIDv7 instead.
 
+    If 'node' is not given, a random 48-bit number is chosen.
+
     If 'clock_seq' is given, it is used as the sequence number;
     otherwise a random 14-bit sequence number is chosen."""
 
@@ -112,12 +114,14 @@ def uuid6(clock_seq: Optional[int] = None) -> UUID:
     _last_v6_timestamp = timestamp
     if clock_seq is None:
         clock_seq = secrets.randbits(14)  # instead of stable storage
+    if node is None:
+        node = secrets.randbits(48)
     time_high_and_time_mid = (timestamp >> 12) & 0xFFFFFFFFFFFF
     time_low_and_version = timestamp & 0x0FFF
     uuid_int = time_high_and_time_mid << 80
     uuid_int |= time_low_and_version << 64
     uuid_int |= (clock_seq & 0x3FFF) << 48
-    uuid_int |= secrets.randbits(48)
+    uuid_int |= node & 0xFFFFFFFFFFFF
     return UUID(int=uuid_int, version=6)
 
 

test/test_vectors.py

@@ -44,10 +44,9 @@ def test_uuid6_from_int(self):
         self.assertEqual(str(uuid_6), "1ec9414c-232a-6b00-b3c8-9e6bdeced846")
 
     @patch("uuid6._last_v6_timestamp", 1)
-    @patch("secrets.randbits", return_value=0x9E6BDECED846)
     @patch("time.time_ns", return_value=0x16D6320C3D4DCC00)
-    def test_uuid6_hex_from_time(self, mocktime, mockrand):
-        uuid_6 = uuid6(0x3C8 | int("11", 2) << 12)
+    def test_uuid6_hex_from_time(self, mocktime):
+        uuid_6 = uuid6(node=0x9E6BDECED846, clock_seq=0x3C8 | int("11", 2) << 12)
         self.assertEqual(str(uuid_6), "1ec9414c-232a-6b00-b3c8-9e6bdeced846")
 
     def test_uuid6_time_from_hex(self):