Hash and cache 128 bytes of UUID

bumble/core.py

@@ -19,6 +19,7 @@
 
 import dataclasses
 import enum
+import functools
 import struct
 from collections.abc import Iterable
 from typing import (
@@ -273,13 +274,8 @@ def parse_uuid(cls, uuid_as_bytes: bytes, offset: int) -> tuple[int, UUID]:
     def parse_uuid_2(cls, uuid_as_bytes: bytes, offset: int) -> tuple[int, UUID]:
         return offset + 2, cls.from_bytes(uuid_as_bytes[offset : offset + 2])
 
-    def to_bytes(self, force_128: bool = False) -> bytes:
-        '''
-        Serialize UUID in little-endian byte-order
-        '''
-        if not force_128:
-            return self.uuid_bytes
-
+    @functools.cached_property
+    def uuid_128_bytes(self) -> bytes:
         match len(self.uuid_bytes):
             case 2:
                 return self.BASE_UUID + self.uuid_bytes + bytes([0, 0])
@@ -290,6 +286,15 @@ def to_bytes(self, force_128: bool = False) -> bytes:
             case _:
                 assert False, "unreachable"
 
+    def to_bytes(self, force_128: bool = False) -> bytes:
+        '''
+        Serialize UUID in little-endian byte-order
+        '''
+        if not force_128:
+            return self.uuid_bytes
+
+        return self.uuid_128_bytes
+
     def to_pdu_bytes(self) -> bytes:
         '''
         Convert to bytes for use in an ATT PDU.
@@ -318,15 +323,15 @@ def __bytes__(self) -> bytes:
 
     def __eq__(self, other: object) -> bool:
         if isinstance(other, UUID):
-            return self.to_bytes(force_128=True) == other.to_bytes(force_128=True)
+            return self.uuid_128_bytes == other.uuid_128_bytes
 
         if isinstance(other, str):
             return UUID(other) == self
 
         return False
 
     def __hash__(self) -> int:
-        return hash(self.uuid_bytes)
+        return hash(self.uuid_128_bytes)
 
     def __str__(self) -> str:
         result = self.to_hex_str(separator='-')

tests/core_test.py

@@ -73,6 +73,14 @@ def test_uuid_to_hex_str() -> None:
     )
 
 
+# -----------------------------------------------------------------------------
+def test_uuid_hash() -> None:
+    uuid = UUID("1234")
+    uuid_128_bytes = UUID.from_bytes(uuid.to_bytes(force_128=True))
+    assert uuid in {uuid_128_bytes}
+    assert uuid_128_bytes in {uuid}
+
+
 # -----------------------------------------------------------------------------
 def test_appearance() -> None:
     a = Appearance(Appearance.Category.COMPUTER, Appearance.ComputerSubcategory.LAPTOP)