Store elapsed time on stream wrapper to avoid reference cycles

src/httpx2/httpx2/_client.py

@@ -132,43 +132,43 @@ class ClientState(enum.Enum):
 
 class BoundSyncStream(SyncByteStream):
     """
-    A byte stream that is bound to a given response instance, and that
-    ensures the `response.elapsed` is set once the response is closed.
+    A byte stream that tracks elapsed time for a response. Once closed, the
+    elapsed time is available via the `elapsed` attribute, and the response
+    can read it back from `response.stream.elapsed`.
     """
 
-    def __init__(self, stream: SyncByteStream, response: Response, start: float) -> None:
+    def __init__(self, stream: SyncByteStream, start: float) -> None:
         self._stream = stream
-        self._response = response
         self._start = start
+        self.elapsed: datetime.timedelta | None = None
 
     def __iter__(self) -> typing.Iterator[bytes]:
         for chunk in self._stream:
             yield chunk
 
     def close(self) -> None:
-        elapsed = time.perf_counter() - self._start
-        self._response.elapsed = datetime.timedelta(seconds=elapsed)
+        self.elapsed = datetime.timedelta(seconds=time.perf_counter() - self._start)
         self._stream.close()
 
 
 class BoundAsyncStream(AsyncByteStream):
     """
-    An async byte stream that is bound to a given response instance, and that
-    ensures the `response.elapsed` is set once the response is closed.
+    An async byte stream that tracks elapsed time for a response. Once closed,
+    the elapsed time is available via the `elapsed` attribute, and the response
+    can read it back from `response.stream.elapsed`.
     """
 
-    def __init__(self, stream: AsyncByteStream, response: Response, start: float) -> None:
+    def __init__(self, stream: AsyncByteStream, start: float) -> None:
         self._stream = stream
-        self._response = response
         self._start = start
+        self.elapsed: datetime.timedelta | None = None
 
     async def __aiter__(self) -> typing.AsyncIterator[bytes]:
         async for chunk in self._stream:
             yield chunk
 
     async def aclose(self) -> None:
-        elapsed = time.perf_counter() - self._start
-        self._response.elapsed = datetime.timedelta(seconds=elapsed)
+        self.elapsed = datetime.timedelta(seconds=time.perf_counter() - self._start)
         await self._stream.aclose()
 
 
@@ -977,7 +977,7 @@ def _send_single_request(self, request: Request) -> Response:
         assert isinstance(response.stream, SyncByteStream)
 
         response.request = request
-        response.stream = BoundSyncStream(response.stream, response=response, start=start)
+        response.stream = BoundSyncStream(response.stream, start=start)
         self.cookies.extract_cookies(response)
         response.default_encoding = self._default_encoding
 
@@ -1680,7 +1680,7 @@ async def _send_single_request(self, request: Request) -> Response:
 
         assert isinstance(response.stream, AsyncByteStream)
         response.request = request
-        response.stream = BoundAsyncStream(response.stream, response=response, start=start)
+        response.stream = BoundAsyncStream(response.stream, start=start)
         self.cookies.extract_cookies(response)
         response.default_encoding = self._default_encoding
 

src/httpx2/httpx2/_models.py

@@ -563,6 +563,9 @@ def elapsed(self) -> datetime.timedelta:
         cycle to complete.
         """
         if not hasattr(self, "_elapsed"):
+            stream_elapsed: datetime.timedelta | None = getattr(self.stream, "elapsed", None)
+            if stream_elapsed is not None:
+                return stream_elapsed
             raise RuntimeError("'.elapsed' may only be accessed after the response has been read or closed.")
         return self._elapsed
 

tests/httpx2/models/test_responses.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import datetime
 import json
 import pickle
 import typing
@@ -771,6 +772,12 @@ async def test_elapsed_not_available_until_closed() -> None:
         response.elapsed  # noqa: B018
 
 
+def test_elapsed_set_directly() -> None:
+    response = httpx2.Response(200)
+    response.elapsed = datetime.timedelta(seconds=1)
+    assert response.elapsed == datetime.timedelta(seconds=1)
+
+
 def test_unknown_status_code() -> None:
     response = httpx2.Response(
         600,