fix: remaining issues with subscriber client (#43)

* fix: Remaining issues with subscriber client.

Fix make_subscriber to defer GRPC client creation.

Fix retrying_connection to not let __aenter__ return until successful initialization or permanent failure.

* chore: reformat

Author: dpcollins-google

google/cloud/pubsublite/cloudpubsub/make_subscriber.py

@@ -88,14 +88,18 @@ def assignment_connection_factory(
 
 def _make_partition_subscriber_factory(
     subscription: SubscriptionPath,
-    subscribe_client: SubscriberServiceAsyncClient,
-    cursor_client: CursorServiceAsyncClient,
+    client_options: ClientOptions,
+    credentials: Optional[Credentials],
     base_metadata: Optional[Mapping[str, str]],
     flow_control_settings: FlowControlSettings,
     nack_handler: NackHandler,
     message_transformer: MessageTransformer,
 ) -> PartitionSubscriberFactory:
     def factory(partition: Partition) -> AsyncSubscriber:
+        subscribe_client = SubscriberServiceAsyncClient(
+            credentials=credentials, client_options=client_options
+        )  # type: ignore
+        cursor_client = CursorServiceAsyncClient(credentials=credentials, client_options=client_options)  # type: ignore
         final_metadata = merge_metadata(
             base_metadata, subscription_routing_metadata(subscription, partition)
         )
@@ -174,25 +178,22 @@ def make_async_subscriber(
     if fixed_partitions:
         assigner_factory = lambda: FixedSetAssigner(fixed_partitions)  # noqa: E731
     else:
-        assignment_client = PartitionAssignmentServiceAsyncClient(
-            credentials=credentials, client_options=client_options
-        )  # type: ignore
         assigner_factory = lambda: _make_dynamic_assigner(  # noqa: E731
-            subscription, assignment_client, metadata
+            subscription,
+            PartitionAssignmentServiceAsyncClient(
+                credentials=credentials, client_options=client_options
+            ),
+            metadata,
         )
 
-    subscribe_client = SubscriberServiceAsyncClient(
-        credentials=credentials, client_options=client_options
-    )  # type: ignore
-    cursor_client = CursorServiceAsyncClient(credentials=credentials, client_options=client_options)  # type: ignore
     if nack_handler is None:
         nack_handler = DefaultNackHandler()
     if message_transformer is None:
         message_transformer = DefaultMessageTransformer()
     partition_subscriber_factory = _make_partition_subscriber_factory(
         subscription,
-        subscribe_client,
-        cursor_client,
+        client_options,
+        credentials,
         metadata,
         per_partition_flow_control_settings,
         nack_handler,

google/cloud/pubsublite/internal/wire/retrying_connection.py

@@ -24,6 +24,7 @@ class RetryingConnection(Connection[Request, Response], PermanentFailable):
 
     _connection_factory: ConnectionFactory[Request, Response]
     _reinitializer: ConnectionReinitializer[Request, Response]
+    _initialized_once: asyncio.Event
 
     _loop_task: asyncio.Future
 
@@ -38,11 +39,13 @@ def __init__(
         super().__init__()
         self._connection_factory = connection_factory
         self._reinitializer = reinitializer
+        self._initialized_once = asyncio.Event()
         self._write_queue = asyncio.Queue(maxsize=1)
         self._read_queue = asyncio.Queue(maxsize=1)
 
     async def __aenter__(self):
         self._loop_task = asyncio.ensure_future(self._run_loop())
+        await self.await_unless_failed(self._initialized_once.wait())
         return self
 
     async def __aexit__(self, exc_type, exc_val, exc_tb):
@@ -76,6 +79,7 @@ async def _run_loop(self):
                         self._read_queue = asyncio.Queue(maxsize=1)
                         self._write_queue = asyncio.Queue(maxsize=1)
                         await self._reinitializer.reinitialize(connection)
+                        self._initialized_once.set()
                         bad_retries = 0
                         await self._loop_connection(connection)
                 except GoogleAPICallError as e:

tests/unit/pubsublite/internal/wire/retrying_connection_test.py

@@ -1,5 +1,4 @@
 import asyncio
-from typing import Union
 
 from asynctest.mock import MagicMock, CoroutineMock
 import pytest
@@ -15,6 +14,7 @@
     RetryingConnection,
     _MIN_BACKOFF_SECS,
 )
+from google.cloud.pubsublite.testing.test_utils import wire_queues
 
 # All test coroutines will be treated as marked.
 pytestmark = pytest.mark.asyncio
@@ -41,7 +41,7 @@ def connection_factory(default_connection):
 
 @pytest.fixture()
 def retrying_connection(connection_factory, reinitializer):
-    return RetryingConnection[int, int](connection_factory, reinitializer)
+    return RetryingConnection(connection_factory, reinitializer)
 
 
 @pytest.fixture
@@ -55,40 +55,27 @@ def asyncio_sleep(monkeypatch):
 async def test_permanent_error_on_reinitializer(
     retrying_connection: Connection[int, int], reinitializer, default_connection
 ):
-    fut = asyncio.Future()
-    reinitialize_called = asyncio.Future()
-
     async def reinit_action(conn):
         assert conn == default_connection
-        reinitialize_called.set_result(None)
-        return await fut
+        raise InvalidArgument("abc")
 
     reinitializer.reinitialize.side_effect = reinit_action
-    async with retrying_connection as _:
-        await reinitialize_called
-        reinitializer.reinitialize.assert_called_once()
-        fut.set_exception(InvalidArgument("abc"))
-        with pytest.raises(InvalidArgument):
-            await retrying_connection.read()
+    with pytest.raises(InvalidArgument):
+        async with retrying_connection as _:
+            pass
 
 
 async def test_successful_reinitialize(
     retrying_connection: Connection[int, int], reinitializer, default_connection
 ):
-    fut = asyncio.Future()
-    reinitialize_called = asyncio.Future()
-
     async def reinit_action(conn):
         assert conn == default_connection
-        reinitialize_called.set_result(None)
-        return await fut
+        return None
+
+    default_connection.read.return_value = 1
 
     reinitializer.reinitialize.side_effect = reinit_action
     async with retrying_connection as _:
-        await reinitialize_called
-        reinitializer.reinitialize.assert_called_once()
-        fut.set_result(None)
-        default_connection.read.return_value = 1
         assert await retrying_connection.read() == 1
         assert (
             default_connection.read.call_count == 2
@@ -111,26 +98,15 @@ async def test_reinitialize_after_retryable(
     default_connection,
     asyncio_sleep,
 ):
-    reinit_called = asyncio.Queue()
-    reinit_results: "asyncio.Queue[Union[None, Exception]]" = asyncio.Queue()
+    reinit_queues = wire_queues(reinitializer.reinitialize)
 
-    async def reinit_action(conn):
-        assert conn == default_connection
-        await reinit_called.put(None)
-        result = await reinit_results.get()
-        if isinstance(result, Exception):
-            raise result
+    default_connection.read.return_value = 1
 
-    reinitializer.reinitialize.side_effect = reinit_action
+    await reinit_queues.results.put(InternalServerError("abc"))
+    await reinit_queues.results.put(None)
     async with retrying_connection as _:
-        await reinit_called.get()
-        reinitializer.reinitialize.assert_called_once()
-        await reinit_results.put(InternalServerError("abc"))
-        await reinit_called.get()
         asyncio_sleep.assert_called_once_with(_MIN_BACKOFF_SECS)
         assert reinitializer.reinitialize.call_count == 2
-        await reinit_results.put(None)
-        default_connection.read.return_value = 1
         assert await retrying_connection.read() == 1
         assert (
             default_connection.read.call_count == 2