From 849228de96bbe32a8d61d56718ddb67b4ef2ad28 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 1 Dec 2024 19:06:29 -0600
Subject: [PATCH] Avoid calling len on the same data in the stream reader twice
 (#10088)

(cherry picked from commit 29c3ca93a4d1793c60d33038151228962f8b6f78)
---
 aiohttp/streams.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/aiohttp/streams.py b/aiohttp/streams.py
index b97846171b1..029d577b88c 100644
--- a/aiohttp/streams.py
+++ b/aiohttp/streams.py
@@ -517,8 +517,9 @@ def _read_nowait_chunk(self, n: int) -> bytes:
         else:
             data = self._buffer.popleft()
 
-        self._size -= len(data)
-        self._cursor += len(data)
+        data_len = len(data)
+        self._size -= data_len
+        self._cursor += data_len
 
         chunk_splits = self._http_chunk_splits
         # Prevent memory leak: drop useless chunk splits