Fix session/workspace life-cycle (#680)

 * don't emit deprecation warning of workspace.__del__ if it was closed already
 * don't import things while executing a destructor (in deprecation warning)
 * unasync _AsyncClassNames as well

Author: robsdedude

bin/make-unasync

@@ -172,6 +172,9 @@ class CustomRule(unasync.Rule):
         # Convert class names from 'AsyncXyz' to 'Xyz'
         if len(name) > 5 and name.startswith("Async") and name[5].isupper():
             return name[5:]
+        # Convert class names from '_AsyncXyz' to '_Xyz'
+        elif len(name) > 6 and name.startswith("_Async") and name[6].isupper():
+            return "_" + name[6:]
         # Convert variable/method/function names from 'async_xyz' to 'xyz'
         elif len(name) > 6 and name.startswith("async_"):
             return name[6:]

neo4j/_async/work/session.py

@@ -147,6 +147,8 @@ async def close(self):
         This will release any borrowed resources, such as connections, and will
         roll back any outstanding transactions.
         """
+        if self._closed:
+            return
         if self._connection:
             if self._auto_result:
                 if self._state_failed is False:

neo4j/_async/work/workspace.py

@@ -45,8 +45,9 @@ def __init__(self, pool, config):
         self._closed = False
 
     def __del__(self):
-        if not self._closed:
-            unclosed_resource_warn(self)
+        if self._closed:
+            return
+        unclosed_resource_warn(self)
         # TODO: 6.0 - remove this
         if asyncio.iscoroutinefunction(self.close):
             return
@@ -120,5 +121,7 @@ async def _disconnect(self, sync=False):
             self._connection_access_mode = None
 
     async def close(self):
+        if self._closed:
+            return
         await self._disconnect(sync=True)
         self._closed = True

neo4j/_sync/work/session.py

@@ -147,6 +147,8 @@ def close(self):
         This will release any borrowed resources, such as connections, and will
         roll back any outstanding transactions.
         """
+        if self._closed:
+            return
         if self._connection:
             if self._auto_result:
                 if self._state_failed is False:

neo4j/_sync/work/transaction.py

@@ -29,7 +29,7 @@
 __all__ = ("Transaction", "ManagedTransaction")
 
 
-class _AsyncTransactionBase:
+class _TransactionBase:
     def __init__(self, connection, fetch_size, on_closed, on_error):
         self._connection = connection
         self._error_handling_connection = ConnectionErrorHandler(
@@ -196,7 +196,7 @@ def _closed(self):
         return self._closed_flag
 
 
-class Transaction(_AsyncTransactionBase):
+class Transaction(_TransactionBase):
     """ Container for multiple Cypher queries to be executed within a single
     context. :class:`Transaction` objects can be used as a context
     managers (:py:const:`with` block) where the transaction is committed
@@ -207,32 +207,32 @@ class Transaction(_AsyncTransactionBase):
 
     """
 
-    @wraps(_AsyncTransactionBase._enter)
+    @wraps(_TransactionBase._enter)
     def __enter__(self):
         return self._enter()
 
-    @wraps(_AsyncTransactionBase._exit)
+    @wraps(_TransactionBase._exit)
     def __exit__(self, exception_type, exception_value, traceback):
         self._exit(exception_type, exception_value, traceback)
 
-    @wraps(_AsyncTransactionBase._commit)
+    @wraps(_TransactionBase._commit)
     def commit(self):
         return self._commit()
 
-    @wraps(_AsyncTransactionBase._rollback)
+    @wraps(_TransactionBase._rollback)
     def rollback(self):
         return self._rollback()
 
-    @wraps(_AsyncTransactionBase._close)
+    @wraps(_TransactionBase._close)
     def close(self):
         return self._close()
 
-    @wraps(_AsyncTransactionBase._closed)
+    @wraps(_TransactionBase._closed)
     def closed(self):
         return self._closed()
 
 
-class ManagedTransaction(_AsyncTransactionBase):
+class ManagedTransaction(_TransactionBase):
     """Transaction object provided to transaction functions.
 
     Inside a transaction function, the driver is responsible for managing

neo4j/_sync/work/workspace.py

@@ -45,8 +45,9 @@ def __init__(self, pool, config):
         self._closed = False
 
     def __del__(self):
-        if not self._closed:
-            unclosed_resource_warn(self)
+        if self._closed:
+            return
+        unclosed_resource_warn(self)
         # TODO: 6.0 - remove this
         if asyncio.iscoroutinefunction(self.close):
             return
@@ -120,5 +121,7 @@ def _disconnect(self, sync=False):
             self._connection_access_mode = None
 
     def close(self):
+        if self._closed:
+            return
         self._disconnect(sync=True)
         self._closed = True

neo4j/meta.py

@@ -18,6 +18,7 @@
 
 import asyncio
 from functools import wraps
+from warnings import warn
 
 
 # Can be automatically overridden in builds
@@ -39,7 +40,6 @@ def get_user_agent():
 
 
 def deprecation_warn(message, stack_level=2):
-    from warnings import warn
     warn(message, category=DeprecationWarning, stacklevel=stack_level)