refactor: change IsolationLevel to Enum

Signed-off-by: Đặng Minh Dũng <dungdm93@live.com>

tests/sqlalchemy/test_dialect.py

@@ -1,12 +1,15 @@
 from typing import List, Any, Dict
+from unittest import mock
 
 import pytest
 from assertpy import assert_that
 from sqlalchemy.engine import make_url
 from sqlalchemy.engine.url import URL
 
 from trino.auth import BasicAuthentication
+from trino.dbapi import Connection
 from trino.sqlalchemy.dialect import TrinoDialect
+from trino.transaction import IsolationLevel
 
 
 class TestTrinoDialect:
@@ -32,3 +35,16 @@ def test_create_connect_args(self, url: URL, expected_args: List[Any], expected_
 
         assert_that(actual_args).is_equal_to(expected_args)
         assert_that(actual_kwargs).is_equal_to(expected_kwargs)
+
+    def test_get_default_isolation_level(self):
+        isolation_level = self.dialect.get_default_isolation_level(mock.Mock())
+        assert_that(isolation_level).is_equal_to('AUTOCOMMIT')
+
+    def test_isolation_level(self):
+        dbapi_conn = Connection(host="localhost")
+
+        self.dialect.set_isolation_level(dbapi_conn, "SERIALIZABLE")
+        assert_that(dbapi_conn._isolation_level).is_equal_to(IsolationLevel.SERIALIZABLE)
+
+        isolation_level = self.dialect.get_isolation_level(dbapi_conn)
+        assert_that(isolation_level).is_equal_to("SERIALIZABLE")

trino/sqlalchemy/dialect.py

@@ -20,7 +20,7 @@
 from trino import dbapi as trino_dbapi
 from trino.auth import BasicAuthentication
 from trino.dbapi import Cursor
-from . import compiler, datatype, error
+from trino.sqlalchemy import compiler, datatype, error
 
 
 class TrinoDialect(DefaultDialect):
@@ -291,16 +291,14 @@ def do_commit_twophase(self, connection: Connection, xid: str,
     def do_recover_twophase(self, connection: Connection) -> None:
         pass
 
-    def set_isolation_level(self, dbapi_conn: trino_dbapi.Connection, level) -> None:
-        dbapi_conn._isolation_level = getattr(trino_dbapi.IsolationLevel, level)
+    def set_isolation_level(self, dbapi_conn: trino_dbapi.Connection, level: str) -> None:
+        dbapi_conn._isolation_level = trino_dbapi.IsolationLevel[level]
 
     def get_isolation_level(self, dbapi_conn: trino_dbapi.Connection) -> str:
-        level_names = ['AUTOCOMMIT',
-                       'READ_UNCOMMITTED',
-                       'READ_COMMITTED',
-                       'REPEATABLE_READ',
-                       'SERIALIZABLE']
-        return level_names[dbapi_conn.isolation_level]
+        return dbapi_conn.isolation_level.name
+
+    def get_default_isolation_level(self, dbapi_conn: trino_dbapi.Connection) -> str:
+        return trino_dbapi.IsolationLevel.AUTOCOMMIT.name
 
     def _get_full_table(self, table_name: str, schema: str = None, quote: bool = True) -> str:
         table_part = self.identifier_preparer.quote_identifier(table_name) if quote else table_name

trino/transaction.py

@@ -9,24 +9,24 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from enum import Enum, unique
 from typing import Iterable
 
-from trino import constants
 import trino.client
 import trino.exceptions
 import trino.logging
-
+from trino import constants
 
 logger = trino.logging.get_logger(__name__)
 
-
 NO_TRANSACTION = "NONE"
 START_TRANSACTION = "START TRANSACTION"
 ROLLBACK = "ROLLBACK"
 COMMIT = "COMMIT"
 
 
-class IsolationLevel(object):
+@unique
+class IsolationLevel(Enum):
     AUTOCOMMIT = 0
     READ_UNCOMMITTED = 1
     READ_COMMITTED = 2
@@ -35,16 +35,16 @@ class IsolationLevel(object):
 
     @classmethod
     def levels(cls) -> Iterable[str]:
-        return {k for k, v in cls.__dict__.items() if not k.startswith("_") and isinstance(v, int)}
+        return {isolation_level.name for isolation_level in IsolationLevel}
 
     @classmethod
     def values(cls) -> Iterable[int]:
-        return {getattr(cls, level) for level in cls.levels()}
+        return {isolation_level.value for isolation_level in IsolationLevel}
 
     @classmethod
     def check(cls, level: int) -> int:
         if level not in cls.values():
-            raise ValueError("invalid isolation level {}".format(level))
+            raise ValueError(f"invalid isolation level {level}")
         return level
 
 
@@ -60,9 +60,7 @@ def id(self):
     def begin(self):
         response = self._request.post(START_TRANSACTION)
         if not response.ok:
-            raise trino.exceptions.DatabaseError(
-                "failed to start transaction: {}".format(response.status_code)
-            )
+            raise trino.exceptions.DatabaseError(f"failed to start transaction: {response.status_code}")
         transaction_id = response.headers.get(constants.HEADER_STARTED_TRANSACTION)
         if transaction_id and transaction_id != NO_TRANSACTION:
             self._id = response.headers[constants.HEADER_STARTED_TRANSACTION]
@@ -74,16 +72,14 @@ def begin(self):
                 self._id = response.headers[constants.HEADER_STARTED_TRANSACTION]
             status = self._request.process(response)
         self._request.transaction_id = self._id
-        logger.info("transaction started: " + self._id)
+        logger.info("transaction started: %s", self._id)
 
     def commit(self):
         query = trino.client.TrinoQuery(self._request, COMMIT)
         try:
             list(query.execute())
         except Exception as err:
-            raise trino.exceptions.DatabaseError(
-                "failed to commit transaction {}: {}".format(self._id, err)
-            )
+            raise trino.exceptions.DatabaseError(f"failed to commit transaction {self._id}") from err
         self._id = NO_TRANSACTION
         self._request.transaction_id = self._id
 
@@ -92,8 +88,6 @@ def rollback(self):
         try:
             list(query.execute())
         except Exception as err:
-            raise trino.exceptions.DatabaseError(
-                "failed to rollback transaction {}: {}".format(self._id, err)
-            )
+            raise trino.exceptions.DatabaseError(f"failed to rollback transaction {self._id}") from err
         self._id = NO_TRANSACTION
         self._request.transaction_id = self._id