Handle cameras that close connections without Connection: close header (#140)

Author: bdraco

onvif/client.py

@@ -114,13 +114,17 @@ class AsyncTransportProtocolErrorHandler(AIOHTTPTransport):
     # once since
     """
 
-    @retry_connection_error(attempts=2, exception=aiohttp.ServerDisconnectedError)
+    @retry_connection_error(
+        attempts=2, exception=aiohttp.ServerDisconnectedError, backoff=0
+    )
     async def post(
         self, address: str, message: str, headers: dict[str, str]
     ) -> httpx.Response:
         return await super().post(address, message, headers)
 
-    @retry_connection_error(attempts=2, exception=aiohttp.ServerDisconnectedError)
+    @retry_connection_error(
+        attempts=2, exception=aiohttp.ServerDisconnectedError, backoff=0
+    )
     async def get(
         self,
         address: str,
@@ -129,6 +133,14 @@ async def get(
     ) -> Response:
         return await super().get(address, params, headers)
 
+    @retry_connection_error(
+        attempts=2, exception=aiohttp.ServerDisconnectedError, backoff=0
+    )
+    async def post_xml(
+        self, address: str, envelope: Any, headers: dict[str, str]
+    ) -> Response:
+        return await super().post_xml(address, envelope, headers)
+
 
 async def _cached_document(url: str) -> Document:
     """Load external XML document from disk."""

onvif/wrappers.py

@@ -19,8 +19,11 @@
 def retry_connection_error(
     attempts: int = DEFAULT_ATTEMPTS,
     exception: type[Exception] = aiohttp.ClientError,
+    backoff: float | None = None,
 ) -> Callable[[Callable[P, Awaitable[T]]], Callable[P, Awaitable[T]]]:
     """Define a wrapper to retry on connection error."""
+    if backoff is None:
+        backoff = BACKOFF_TIME
 
     def _decorator_retry_connection_error(
         func: Callable[P, Awaitable[T]],
@@ -35,8 +38,17 @@ def _decorator_retry_connection_error(
         async def _async_wrap_connection_error_retry(  # type: ignore[return]
             *args: P.args, **kwargs: P.kwargs
         ) -> T:
+            logger.debug(
+                "retry_connection_error wrapper called for %s with exception=%s, attempts=%s",
+                func.__name__,
+                exception,
+                attempts,
+            )
             for attempt in range(attempts):
                 try:
+                    logger.debug(
+                        "Attempt %s/%s for %s", attempt + 1, attempts, func.__name__
+                    )
                     return await func(*args, **kwargs)
                 except exception as ex:
                     #
@@ -49,16 +61,25 @@ async def _async_wrap_connection_error_retry(  # type: ignore[return]
                     # to close the connection at any time, we treat this as a normal and try again
                     # once since we do not want to declare the camera as not supporting PullPoint
                     # if it just happened to close the connection at the wrong time.
+                    logger.debug(
+                        "Caught exception %s (type: %s) on attempt %s/%s",
+                        ex,
+                        type(ex).__name__,
+                        attempt + 1,
+                        attempts,
+                        exc_info=True,
+                    )
                     if attempt == attempts - 1:
+                        logger.debug("Final attempt failed, re-raising exception")
                         raise
                     logger.debug(
                         "Error: %s while calling %s, backing off: %s, retrying...",
                         ex,
                         func,
-                        BACKOFF_TIME,
+                        backoff,
                         exc_info=True,
                     )
-                    await asyncio.sleep(BACKOFF_TIME)
+                    await asyncio.sleep(backoff)
 
         return _async_wrap_connection_error_retry