Use ciso8601 for parsing MySQLdb datetimes (#71818)

* Use ciso8601 for parsing MySQLDB datetimes

The default parser is this:

5340191feb/MySQLdb/times.py (L66)

* tweak

* tweak

* add coverage for building the MySQLdb connect conv param

homeassistant/components/recorder/const.py

@@ -10,6 +10,7 @@ from homeassistant.helpers.json import JSONEncoder
 
 DATA_INSTANCE = "recorder_instance"
 SQLITE_URL_PREFIX = "sqlite://"
+MYSQLDB_URL_PREFIX = "mysql://"
 DOMAIN = "recorder"
 
 CONF_DB_INTEGRITY_CHECK = "db_integrity_check"

homeassistant/components/recorder/core.py

@@ -41,6 +41,7 @@ from .const import (
     DB_WORKER_PREFIX,
     KEEPALIVE_TIME,
     MAX_QUEUE_BACKLOG,
+    MYSQLDB_URL_PREFIX,
     SQLITE_URL_PREFIX,
     SupportedDialect,
 )
@@ -77,6 +78,7 @@ from .tasks import (
     WaitTask,
 )
 from .util import (
+    build_mysqldb_conv,
     dburl_to_path,
     end_incomplete_runs,
     is_second_sunday,
@@ -1014,6 +1016,14 @@ class Recorder(threading.Thread):
             kwargs["pool_reset_on_return"] = None
         elif self.db_url.startswith(SQLITE_URL_PREFIX):
             kwargs["poolclass"] = RecorderPool
+        elif self.db_url.startswith(MYSQLDB_URL_PREFIX):
+            # If they have configured MySQLDB but don't have
+            # the MySQLDB module installed this will throw
+            # an ImportError which we suppress here since
+            # sqlalchemy will give them a better error when
+            # it tried to import it below.
+            with contextlib.suppress(ImportError):
+                kwargs["connect_args"] = {"conv": build_mysqldb_conv()}
         else:
             kwargs["echo"] = False
 

homeassistant/components/recorder/util.py

@@ -15,6 +15,7 @@ from awesomeversion import (
     AwesomeVersionException,
     AwesomeVersionStrategy,
 )
+import ciso8601
 from sqlalchemy import text
 from sqlalchemy.engine.cursor import CursorFetchStrategy
 from sqlalchemy.exc import OperationalError, SQLAlchemyError
@@ -331,6 +332,30 @@ def _extract_version_from_server_response(
         return None
 
 
+def _datetime_or_none(value: str) -> datetime | None:
+    """Fast version of mysqldb DateTime_or_None.
+
+    https://github.com/PyMySQL/mysqlclient/blob/v2.1.0/MySQLdb/times.py#L66
+    """
+    try:
+        return ciso8601.parse_datetime(value)
+    except ValueError:
+        return None
+
+
+def build_mysqldb_conv() -> dict:
+    """Build a MySQLDB conv dict that uses cisco8601 to parse datetimes."""
+    # Late imports since we only call this if they are using mysqldb
+    from MySQLdb.constants import (  # pylint: disable=import-outside-toplevel,import-error
+        FIELD_TYPE,
+    )
+    from MySQLdb.converters import (  # pylint: disable=import-outside-toplevel,import-error
+        conversions,
+    )
+
+    return {**conversions, FIELD_TYPE.DATETIME: _datetime_or_none}
+
+
 def setup_connection_for_dialect(
     instance: Recorder,
     dialect_name: str,

tests/components/recorder/test_util.py

@@ -2,7 +2,7 @@
 from datetime import datetime, timedelta
 import os
 import sqlite3
-from unittest.mock import MagicMock, patch
+from unittest.mock import MagicMock, Mock, patch
 
 import pytest
 from sqlalchemy import text
@@ -641,3 +641,20 @@ def test_is_second_sunday():
     assert is_second_sunday(datetime(2022, 5, 8, 0, 0, 0, tzinfo=dt_util.UTC)) is True
 
     assert is_second_sunday(datetime(2022, 1, 10, 0, 0, 0, tzinfo=dt_util.UTC)) is False
+
+
+def test_build_mysqldb_conv():
+    """Test building the MySQLdb connect conv param."""
+    mock_converters = Mock(conversions={"original": "preserved"})
+    mock_constants = Mock(FIELD_TYPE=Mock(DATETIME="DATETIME"))
+    with patch.dict(
+        "sys.modules",
+        **{"MySQLdb.constants": mock_constants, "MySQLdb.converters": mock_converters},
+    ):
+        conv = util.build_mysqldb_conv()
+
+    assert conv["original"] == "preserved"
+    assert conv["DATETIME"]("INVALID") is None
+    assert conv["DATETIME"]("2022-05-13T22:33:12.741") == datetime(
+        2022, 5, 13, 22, 33, 12, 741000, tzinfo=None
+    )