From d684195bb5cb90a85a07b98127a298f3b1ae2ef3 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Tue, 1 Oct 2024 12:02:54 -0500
Subject: [PATCH] Speed up the ConnectionKey (#9365)

---
 CHANGES/9365.breaking.rst |  1 +
 aiohttp/client_reqrep.py  | 24 +++++++++++++++---------
 aiohttp/connector.py      |  5 ++---
 3 files changed, 18 insertions(+), 12 deletions(-)
 create mode 100644 CHANGES/9365.breaking.rst

diff --git a/CHANGES/9365.breaking.rst b/CHANGES/9365.breaking.rst
new file mode 100644
index 00000000000..f0224170f07
--- /dev/null
+++ b/CHANGES/9365.breaking.rst
@@ -0,0 +1 @@
+Changed ``ClientRequest.connection_key`` to be a `NamedTuple` to improve client performance -- by :user:`bdraco`.
diff --git a/aiohttp/client_reqrep.py b/aiohttp/client_reqrep.py
index 499ca012a88..b8ea586ead5 100644
--- a/aiohttp/client_reqrep.py
+++ b/aiohttp/client_reqrep.py
@@ -19,6 +19,7 @@
     Iterable,
     List,
     Mapping,
+    NamedTuple,
     Optional,
     Tuple,
     Type,
@@ -150,8 +151,13 @@ def check(self, transport: asyncio.Transport) -> None:
     SSL_ALLOWED_TYPES = (bool,)
 
 
-@dataclasses.dataclass(frozen=True)
-class ConnectionKey:
+_SSL_SCHEMES = frozenset(("https", "wss"))
+
+
+# ConnectionKey is a NamedTuple because it is used as a key in a dict
+# and a set in the connector. Since a NamedTuple is a tuple it uses
+# the fast native tuple __hash__ and __eq__ implementation in CPython.
+class ConnectionKey(NamedTuple):
     # the key should contain an information about used proxy / TLS
     # to prevent reusing wrong connections from a pool
     host: str
@@ -287,7 +293,7 @@ def _writer(self, writer: Optional["asyncio.Task[None]"]) -> None:
             writer.add_done_callback(self.__reset_writer)
 
     def is_ssl(self) -> bool:
-        return self.url.scheme in ("https", "wss")
+        return self.url.scheme in _SSL_SCHEMES
 
     @property
     def ssl(self) -> Union["SSLContext", bool, Fingerprint]:
@@ -295,16 +301,16 @@ def ssl(self) -> Union["SSLContext", bool, Fingerprint]:
 
     @property
     def connection_key(self) -> ConnectionKey:
-        proxy_headers = self.proxy_headers
-        if proxy_headers:
+        if proxy_headers := self.proxy_headers:
             h: Optional[int] = hash(tuple(proxy_headers.items()))
         else:
             h = None
+        url = self.url
         return ConnectionKey(
-            self.host,
-            self.port,
-            self.is_ssl(),
-            self.ssl,
+            url.raw_host or "",
+            url.port,
+            url.scheme in _SSL_SCHEMES,
+            self._ssl,
             self.proxy,
             self.proxy_auth,
             h,
diff --git a/aiohttp/connector.py b/aiohttp/connector.py
index 45f766b0fcc..1237f3c74d4 100644
--- a/aiohttp/connector.py
+++ b/aiohttp/connector.py
@@ -1,5 +1,4 @@
 import asyncio
-import dataclasses
 import functools
 import logging
 import random
@@ -1312,8 +1311,8 @@ async def _create_proxy_connection(
             # asyncio handles this perfectly
             proxy_req.method = hdrs.METH_CONNECT
             proxy_req.url = req.url
-            key = dataclasses.replace(
-                req.connection_key, proxy=None, proxy_auth=None, proxy_headers_hash=None
+            key = req.connection_key._replace(
+                proxy=None, proxy_auth=None, proxy_headers_hash=None
             )
             conn = Connection(self, key, proto, self._loop)
             proxy_resp = await proxy_req.send(conn)