From c3fe9802ee8cb649785bf4333d307bafc1051ab9 Mon Sep 17 00:00:00 2001
From: Alexandros Tzannes <alexandros.tzannes@aprioriinvestments.com>
Date: Fri, 14 Mar 2025 17:08:38 -0400
Subject: [PATCH 1/2] Use io.BytesIO() instead of List[bytes] + b"".join()

---
 aiohttp/streams.py | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/aiohttp/streams.py b/aiohttp/streams.py
index db22f162396..aaa20c08848 100644
--- a/aiohttp/streams.py
+++ b/aiohttp/streams.py
@@ -1,5 +1,6 @@
 import asyncio
 import collections
+import io
 import warnings
 from typing import (
     Awaitable,
@@ -399,12 +400,13 @@ async def read(self, n: int = -1) -> bytes:
             # deadlock if the subprocess sends more than self.limit
             # bytes.  So just call self.readany() until EOF.
             blocks = []
+            buffer = io.BytesIO()
             while True:
                 block = await self.readany()
                 if not block:
                     break
-                blocks.append(block)
-            return b"".join(blocks)
+                buffer.write(block)
+            return buffer.getvalue()
 
         # TODO: should be `if` instead of `while`
         # because waiter maybe triggered on chunk end,
@@ -464,16 +466,16 @@ async def readexactly(self, n: int) -> bytes:
         if self._exception is not None:
             raise self._exception
 
-        blocks: List[bytes] = []
+        buffer = io.BytesIO()
         while n > 0:
             block = await self.read(n)
             if not block:
-                partial = b"".join(blocks)
+                partial = buffer.getvalue()
                 raise asyncio.IncompleteReadError(partial, len(partial) + n)
-            blocks.append(block)
+            buffer.write(block)
             n -= len(block)
 
-        return b"".join(blocks)
+        return buffer.getvalue()
 
     def read_nowait(self, n: int = -1) -> bytes:
         # default was changed to be consistent with .read(-1)
@@ -523,15 +525,16 @@ def _read_nowait(self, n: int) -> bytes:
         self._timer.assert_timeout()
 
         chunks = []
+        buffer = io.BytesIO()
         while self._buffer:
             chunk = self._read_nowait_chunk(n)
-            chunks.append(chunk)
+            buffer.write(chunk)
             if n != -1:
                 n -= len(chunk)
                 if n == 0:
                     break
 
-        return b"".join(chunks) if chunks else b""
+        return buffer.getvalue()
 
 
 class EmptyStreamReader(StreamReader):  # lgtm [py/missing-call-to-init]

From a6969b40e64d69fc6b038355203984ded0415a8f Mon Sep 17 00:00:00 2001
From: Alexandros Tzannes <alexandros.tzannes@aprioriinvestments.com>
Date: Tue, 18 Mar 2025 17:21:48 -0400
Subject: [PATCH 2/2] Clean up unused code

---
 aiohttp/streams.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/aiohttp/streams.py b/aiohttp/streams.py
index aaa20c08848..bf090cd8925 100644
--- a/aiohttp/streams.py
+++ b/aiohttp/streams.py
@@ -399,7 +399,6 @@ async def read(self, n: int = -1) -> bytes:
             # collect everything in self._buffer, but that would
             # deadlock if the subprocess sends more than self.limit
             # bytes.  So just call self.readany() until EOF.
-            blocks = []
             buffer = io.BytesIO()
             while True:
                 block = await self.readany()
@@ -524,7 +523,6 @@ def _read_nowait(self, n: int) -> bytes:
         """Read not more than n bytes, or whole buffer if n == -1"""
         self._timer.assert_timeout()
 
-        chunks = []
         buffer = io.BytesIO()
         while self._buffer:
             chunk = self._read_nowait_chunk(n)