Add logging for input and output event streams (smithy-lang#408)

Author: jonathan343

packages/aws-event-stream/src/aws_event_stream/_private/deserializers.py

@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0
 import asyncio
 import datetime
+import logging
 from collections.abc import Callable
 
 from smithy_core.aio.interfaces import AsyncByteStream
@@ -25,6 +26,8 @@
 )
 from smithy_core.traits import EventHeaderTrait
 
+logger = logging.getLogger(__name__)
+
 INITIAL_MESSAGE_TYPES = (INITIAL_REQUEST_EVENT_TYPE, INITIAL_RESPONSE_EVENT_TYPE)
 
 
@@ -55,14 +58,17 @@ async def receive(self) -> E | None:
             raise
 
         if event is None:
+            logger.debug("No event received from the source.")
             return None
+        logger.debug("Received raw event: %s", event)
 
         deserializer = EventDeserializer(
             event=event,
             payload_codec=self._payload_codec,
             is_client_mode=self._is_client_mode,
         )
         result = self._deserializer(deserializer)
+        logger.debug("Successfully deserialized event: %s", result)
         if isinstance(getattr(result, "value"), Exception):
             raise result.value  # type: ignore
         return result

packages/aws-event-stream/src/aws_event_stream/_private/serializers.py

@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0
 import asyncio
 import datetime
+import logging
 from collections.abc import Callable, Iterator
 from contextlib import contextmanager
 from io import BytesIO
@@ -29,6 +30,8 @@
 )
 from smithy_core.traits import ErrorTrait, EventHeaderTrait, MediaTypeTrait
 
+logger = logging.getLogger(__name__)
+
 _DEFAULT_STRING_CONTENT_TYPE = "text/plain"
 _DEFAULT_BLOB_CONTENT_TYPE = "application/octet-stream"
 
@@ -55,6 +58,7 @@ def __init__(
     async def send(self, event: E) -> None:
         if self._closed:
             raise IOError("Attempted to write to closed stream.")
+        logger.debug("Preparing to publish event: %s", event)
         event.serialize(self._serializer)
         result = self._serializer.get_result()
         if result is None:
@@ -66,6 +70,7 @@ async def send(self, event: E) -> None:
 
         encoded_result = result.encode()
         try:
+            logger.debug("Publishing serialized event: %s", result)
             await self._writer.write(encoded_result)
         except Exception as e:
             await self.close()