Improve performance of generating non-cryptographically secure uuids (#41314)

homeassistant/config_entries.py

@@ -139,7 +139,7 @@ class ConfigEntry:
     ) -> None:
         """Initialize a config entry."""
         # Unique id of the config entry
-        self.entry_id = entry_id or uuid_util.uuid_v1mc_hex()
+        self.entry_id = entry_id or uuid_util.random_uuid_hex()
 
         # Version of the configuration.
         self.version = version

homeassistant/core.py

@@ -511,7 +511,7 @@ class Context:
 
     user_id: str = attr.ib(default=None)
     parent_id: Optional[str] = attr.ib(default=None)
-    id: str = attr.ib(factory=uuid_util.uuid_v1mc_hex)
+    id: str = attr.ib(factory=uuid_util.random_uuid_hex)
 
     def as_dict(self) -> dict:
         """Return a dictionary representation of the context."""

homeassistant/helpers/area_registry.py

@@ -26,7 +26,7 @@ class AreaEntry:
     """Area Registry Entry."""
 
     name: Optional[str] = attr.ib(default=None)
-    id: str = attr.ib(factory=uuid_util.uuid_v1mc_hex)
+    id: str = attr.ib(factory=uuid_util.random_uuid_hex)
 
 
 class AreaRegistry:

homeassistant/helpers/device_registry.py

@@ -73,7 +73,7 @@ class DeviceEntry:
     area_id: str = attr.ib(default=None)
     name_by_user: str = attr.ib(default=None)
     entry_type: str = attr.ib(default=None)
-    id: str = attr.ib(factory=uuid_util.uuid_v1mc_hex)
+    id: str = attr.ib(factory=uuid_util.random_uuid_hex)
     # This value is not stored, just used to keep track of events to fire.
     is_new: bool = attr.ib(default=False)
 

homeassistant/util/uuid.py

@@ -1,15 +1,12 @@
 """Helpers to generate uuids."""
 
-import random
+from random import getrandbits
-import uuid
 
 
-def uuid_v1mc_hex() -> str:
+def random_uuid_hex() -> str:
-    """Generate a uuid1 with a random multicast MAC address.
+    """Generate a random UUID hex.
 
-    The uuid1 uses a random multicast MAC address instead of the real MAC address
+    This uuid should not be used for cryptographically secure
-    of the machine without the overhead of calling the getrandom() system call.
+    operations.
-
-    This is effectively equivalent to PostgreSQL's uuid_generate_v1mc() function
     """
-    return uuid.uuid1(node=random.getrandbits(48) | (1 << 40)).hex
+    return "%032x" % getrandbits(32 * 4)

tests/util/test_uuid.py

@@ -5,7 +5,7 @@ import uuid
 import homeassistant.util.uuid as uuid_util
 
 
-async def test_uuid_v1mc_hex():
+async def test_uuid_util_random_uuid_hex():
-    """Verify we can generate a uuid_v1mc and return hex."""
+    """Verify we can generate a random uuid."""
-    assert len(uuid_util.uuid_v1mc_hex()) == 32
+    assert len(uuid_util.random_uuid_hex()) == 32
-    assert uuid.UUID(uuid_util.uuid_v1mc_hex())
+    assert uuid.UUID(uuid_util.random_uuid_hex())