[PR #9722/fbf555c backport][3.11] Simplify header and method lookups (#9724)

Author: bdraco

CHANGES/9722.misc.rst

@@ -0,0 +1 @@
+Replace internal helper methods ``method_must_be_empty_body`` and ``status_code_must_be_empty_body`` with simple `set` lookups -- by :user:`bdraco`.

aiohttp/client.py

@@ -92,10 +92,10 @@
 from .helpers import (
     _SENTINEL,
     DEBUG,
+    EMPTY_BODY_METHODS,
     BasicAuth,
     TimeoutHandle,
     get_env_proxy_for_url,
-    method_must_be_empty_body,
     sentinel,
     strip_auth_from_url,
 )
@@ -706,7 +706,7 @@ async def _request(
                     assert conn.protocol is not None
                     conn.protocol.set_response_params(
                         timer=timer,
-                        skip_payload=method_must_be_empty_body(method),
+                        skip_payload=method in EMPTY_BODY_METHODS,
                         read_until_eof=read_until_eof,
                         auto_decompress=auto_decompress,
                         read_timeout=real_timeout.sock_read,

aiohttp/client_proto.py

@@ -11,9 +11,9 @@
 )
 from .helpers import (
     _EXC_SENTINEL,
+    EMPTY_BODY_STATUS_CODES,
     BaseTimerContext,
     set_exception,
-    status_code_must_be_empty_body,
 )
 from .http import HttpResponseParser, RawResponseMessage
 from .http_exceptions import HttpProcessingError
@@ -284,9 +284,7 @@ def data_received(self, data: bytes) -> None:
 
                     self._payload = payload
 
-                    if self._skip_payload or status_code_must_be_empty_body(
-                        message.code
-                    ):
+                    if self._skip_payload or message.code in EMPTY_BODY_STATUS_CODES:
                         self.feed_data((message, EMPTY_PAYLOAD), 0)
                     else:
                         self.feed_data((message, payload), 0)

aiohttp/client_reqrep.py

@@ -3,7 +3,6 @@
 import contextlib
 import functools
 import io
-import itertools
 import re
 import sys
 import traceback
@@ -239,9 +238,6 @@ class ClientRequest:
     }
     POST_METHODS = {hdrs.METH_PATCH, hdrs.METH_POST, hdrs.METH_PUT}
     ALL_METHODS = GET_METHODS.union(POST_METHODS).union({hdrs.METH_DELETE})
-    _HOST_STRINGS = frozenset(
-        map("".join, itertools.product(*zip("host".upper(), "host".lower())))
-    )
 
     DEFAULT_HEADERS = {
         hdrs.ACCEPT: "*/*",
@@ -445,7 +441,7 @@ def update_headers(self, headers: Optional[LooseHeaders]) -> None:
 
         for key, value in headers:  # type: ignore[misc]
             # A special case for Host header
-            if key in self._HOST_STRINGS:
+            if key in hdrs.HOST_ALL:
                 self.headers[key] = value
             else:
                 self.headers.add(key, value)

aiohttp/hdrs.py

@@ -2,6 +2,7 @@
 
 # After changing the file content call ./tools/gen.py
 # to regenerate the headers parser
+import itertools
 from typing import Final, Set
 
 from multidict import istr
@@ -106,3 +107,15 @@
 X_FORWARDED_FOR: Final[istr] = istr("X-Forwarded-For")
 X_FORWARDED_HOST: Final[istr] = istr("X-Forwarded-Host")
 X_FORWARDED_PROTO: Final[istr] = istr("X-Forwarded-Proto")
+
+# These are the upper/lower case variants of the headers/methods
+# Example: {'hOst', 'host', 'HoST', 'HOSt', 'hOsT', 'HosT', 'hoSt', ...}
+METH_HEAD_ALL: Final = frozenset(
+    map("".join, itertools.product(*zip(METH_HEAD.upper(), METH_HEAD.lower())))
+)
+METH_CONNECT_ALL: Final = frozenset(
+    map("".join, itertools.product(*zip(METH_CONNECT.upper(), METH_CONNECT.lower())))
+)
+HOST_ALL: Final = frozenset(
+    map("".join, itertools.product(*zip(HOST.upper(), HOST.lower())))
+)

aiohttp/helpers.py

@@ -75,6 +75,12 @@
 
 NO_EXTENSIONS = bool(os.environ.get("AIOHTTP_NO_EXTENSIONS"))
 
+# https://datatracker.ietf.org/doc/html/rfc9112#section-6.3-2.1
+EMPTY_BODY_STATUS_CODES = frozenset((204, 304, *range(100, 200)))
+# https://datatracker.ietf.org/doc/html/rfc9112#section-6.3-2.1
+# https://datatracker.ietf.org/doc/html/rfc9112#section-6.3-2.2
+EMPTY_BODY_METHODS = hdrs.METH_HEAD_ALL
+
 DEBUG = sys.flags.dev_mode or (
     not sys.flags.ignore_environment and bool(os.environ.get("PYTHONASYNCIODEBUG"))
 )
@@ -919,34 +925,19 @@ def parse_http_date(date_str: Optional[str]) -> Optional[datetime.datetime]:
 def must_be_empty_body(method: str, code: int) -> bool:
     """Check if a request must return an empty body."""
     return (
-        status_code_must_be_empty_body(code)
-        or method_must_be_empty_body(method)
-        or (200 <= code < 300 and method.upper() == hdrs.METH_CONNECT)
+        code in EMPTY_BODY_STATUS_CODES
+        or method in EMPTY_BODY_METHODS
+        or (200 <= code < 300 and method in hdrs.METH_CONNECT_ALL)
     )
 
 
-def method_must_be_empty_body(method: str) -> bool:
-    """Check if a method must return an empty body."""
-    # https://datatracker.ietf.org/doc/html/rfc9112#section-6.3-2.1
-    # https://datatracker.ietf.org/doc/html/rfc9112#section-6.3-2.2
-    return method.upper() == hdrs.METH_HEAD
-
-
-def status_code_must_be_empty_body(code: int) -> bool:
-    """Check if a status code must return an empty body."""
-    # https://datatracker.ietf.org/doc/html/rfc9112#section-6.3-2.1
-    return code in {204, 304} or 100 <= code < 200
-
-
 def should_remove_content_length(method: str, code: int) -> bool:
     """Check if a Content-Length header should be removed.
 
     This should always be a subset of must_be_empty_body
     """
     # https://www.rfc-editor.org/rfc/rfc9110.html#section-8.6-8
     # https://www.rfc-editor.org/rfc/rfc9110.html#section-15.4.5-4
-    return (
-        code in {204, 304}
-        or 100 <= code < 200
-        or (200 <= code < 300 and method.upper() == hdrs.METH_CONNECT)
+    return code in EMPTY_BODY_STATUS_CODES or (
+        200 <= code < 300 and method in hdrs.METH_CONNECT_ALL
     )

aiohttp/http_parser.py

@@ -30,11 +30,11 @@
 from .helpers import (
     _EXC_SENTINEL,
     DEBUG,
+    EMPTY_BODY_METHODS,
+    EMPTY_BODY_STATUS_CODES,
     NO_EXTENSIONS,
     BaseTimerContext,
-    method_must_be_empty_body,
     set_exception,
-    status_code_must_be_empty_body,
 )
 from .http_exceptions import (
     BadHttpMessage,
@@ -376,8 +376,8 @@ def get_content_length() -> Optional[int]:
 
                         assert self.protocol is not None
                         # calculate payload
-                        empty_body = status_code_must_be_empty_body(code) or bool(
-                            method and method_must_be_empty_body(method)
+                        empty_body = code in EMPTY_BODY_STATUS_CODES or bool(
+                            method and method in EMPTY_BODY_METHODS
                         )
                         if not empty_body and (
                             ((length is not None and length > 0) or msg.chunked)

aiohttp/web_response.py

@@ -776,7 +776,7 @@ async def _start(self, request: "BaseRequest") -> AbstractStreamWriter:
                 body_len = len(self._body) if self._body else "0"
                 # https://www.rfc-editor.org/rfc/rfc9110.html#section-8.6-7
                 if body_len != "0" or (
-                    self.status != 304 and request.method.upper() != hdrs.METH_HEAD
+                    self.status != 304 and request.method not in hdrs.METH_HEAD_ALL
                 ):
                     self._headers[hdrs.CONTENT_LENGTH] = str(body_len)
 

tests/test_helpers.py

@@ -15,7 +15,7 @@
 
 from aiohttp import helpers
 from aiohttp.helpers import (
-    method_must_be_empty_body,
+    EMPTY_BODY_METHODS,
     must_be_empty_body,
     parse_http_date,
     should_remove_content_length,
@@ -897,9 +897,9 @@ def test_read_basicauth_from_empty_netrc():
 
 def test_method_must_be_empty_body():
     """Test that HEAD is the only method that unequivocally must have an empty body."""
-    assert method_must_be_empty_body("HEAD") is True
+    assert "HEAD" in EMPTY_BODY_METHODS
     # CONNECT is only empty on a successful response
-    assert method_must_be_empty_body("CONNECT") is False
+    assert "CONNECT" not in EMPTY_BODY_METHODS
 
 
 def test_should_remove_content_length_is_subset_of_must_be_empty_body():