UUIDv7 Draft 3 will simplify node generation (#21)

Author: oittaa

src/uuid6/__init__.py

@@ -66,7 +66,7 @@ def time(self) -> int:
                 | (self.time_hi_version & 0x0FFF)
             )
         if self.version == 7:
-            return self.unixts * 10 ** 9 + _subsec_decode(self.subsec)
+            return self.unixts * 10**9 + _subsec_decode(self.subsec)
         return super().time
 
     @property
@@ -75,11 +75,11 @@ def unixts(self) -> int:
 
 
 def _subsec_decode(value: int) -> int:
-    return -(-value * 10 ** 9 // 2 ** 30)
+    return -(-value * 10**9 // 2**30)
 
 
 def _subsec_encode(value: int) -> int:
-    return value * 2 ** 30 // 10 ** 9
+    return value * 2**30 // 10**9
 
 
 _last_v6_timestamp = None
@@ -127,14 +127,12 @@ def uuid7() -> UUID:
     if _last_v7_timestamp is not None and nanoseconds <= _last_v7_timestamp:
         nanoseconds = _last_v7_timestamp + 1
     _last_v7_timestamp = nanoseconds
-    timestamp_s, timestamp_ns = divmod(nanoseconds, 10 ** 9)
+    timestamp_s, timestamp_ns = divmod(nanoseconds, 10**9)
     subsec = _subsec_encode(timestamp_ns)
     subsec_a = subsec >> 18
     subsec_b = (subsec >> 6) & 0x0FFF
     subsec_c = subsec & 0x3F
-    rand = 0
-    while rand == 0:
-        rand = secrets.randbits(56)
+    rand = secrets.randbits(56)
     uuid_int = (timestamp_s & 0x0FFFFFFFFF) << 92
     uuid_int |= subsec_a << 80
     uuid_int |= subsec_b << 64

test/test_uuid6.py

@@ -1,11 +1,12 @@
 import unittest
+from datetime import datetime
 from time import time_ns
 from unittest.mock import patch
 from uuid import uuid1
 
 from uuid6 import DraftUUID, uuid6, uuid7
 
-YEAR_IN_NS = 3600 * 24 * 36525 * 10 ** 7
+YEAR_IN_NS = 3600 * 24 * 36525 * 10**7
 
 
 class DraftUUIDTests(unittest.TestCase):
@@ -100,10 +101,24 @@ def test_uuid7_far_in_future(self):
     def test_time(self):
         uuid_1 = uuid1()
         uuid_6 = uuid6()
-        self.assertAlmostEqual(uuid_6.time / 10 ** 7, uuid_1.time / 10 ** 7, 3)
+        self.assertAlmostEqual(uuid_6.time / 10**7, uuid_1.time / 10**7, 3)
         cur_time = time_ns()
         uuid_7 = uuid7()
-        self.assertAlmostEqual(uuid_7.time / 10 ** 9, cur_time / 10 ** 9, 3)
+        self.assertAlmostEqual(uuid_7.time / 10**9, cur_time / 10**9, 3)
+
+    def test_time_zero(self):
+        uuid_6 = DraftUUID(hex="00000000-0000-6000-8000-000000000000")
+        self.assertEqual(uuid_6.time, 0)
+        uuid_7 = DraftUUID(hex="00000000-0000-7000-8000-000000000000")
+        self.assertEqual(uuid_7.time, 0)
+
+    def test_time_max(self):
+        uuid_6 = DraftUUID(hex="ffffffff-ffff-6fff-bfff-ffffffffffff")
+        self.assertEqual(uuid_6.time, 1152921504606846975)
+        uuid_7 = DraftUUID(hex="ffffffff-ffff-7fff-bfff-ffffffffffff")
+        self.assertEqual(uuid_7.time, 68719476736000000000)
+        dt = datetime.utcfromtimestamp(uuid_7.time / 10**9)
+        self.assertEqual(dt, datetime(4147, 8, 20, 7, 32, 16))
 
     def test_uuid7_from_hex(self):
         uuid_7 = DraftUUID(hex="061d0edc-bea0-75cc-9892-f6295fd7d295")