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Diffstat (limited to '.venv/lib/python3.12/site-packages/aiohttp/helpers.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/aiohttp/helpers.py | 958 |
1 files changed, 958 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/aiohttp/helpers.py b/.venv/lib/python3.12/site-packages/aiohttp/helpers.py new file mode 100644 index 00000000..ace4f0e9 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/aiohttp/helpers.py @@ -0,0 +1,958 @@ +"""Various helper functions""" + +import asyncio +import base64 +import binascii +import contextlib +import datetime +import enum +import functools +import inspect +import netrc +import os +import platform +import re +import sys +import time +import weakref +from collections import namedtuple +from contextlib import suppress +from email.parser import HeaderParser +from email.utils import parsedate +from math import ceil +from pathlib import Path +from types import MappingProxyType, TracebackType +from typing import ( + Any, + Callable, + ContextManager, + Dict, + Generator, + Generic, + Iterable, + Iterator, + List, + Mapping, + Optional, + Protocol, + Tuple, + Type, + TypeVar, + Union, + get_args, + overload, +) +from urllib.parse import quote +from urllib.request import getproxies, proxy_bypass + +import attr +from multidict import MultiDict, MultiDictProxy, MultiMapping +from propcache.api import under_cached_property as reify +from yarl import URL + +from . import hdrs +from .log import client_logger + +if sys.version_info >= (3, 11): + import asyncio as async_timeout +else: + import async_timeout + +__all__ = ("BasicAuth", "ChainMapProxy", "ETag", "reify") + +IS_MACOS = platform.system() == "Darwin" +IS_WINDOWS = platform.system() == "Windows" + +PY_310 = sys.version_info >= (3, 10) +PY_311 = sys.version_info >= (3, 11) + + +_T = TypeVar("_T") +_S = TypeVar("_S") + +_SENTINEL = enum.Enum("_SENTINEL", "sentinel") +sentinel = _SENTINEL.sentinel + +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")) +) + + +CHAR = {chr(i) for i in range(0, 128)} +CTL = {chr(i) for i in range(0, 32)} | { + chr(127), +} +SEPARATORS = { + "(", + ")", + "<", + ">", + "@", + ",", + ";", + ":", + "\\", + '"', + "/", + "[", + "]", + "?", + "=", + "{", + "}", + " ", + chr(9), +} +TOKEN = CHAR ^ CTL ^ SEPARATORS + + +class noop: + def __await__(self) -> Generator[None, None, None]: + yield + + +class BasicAuth(namedtuple("BasicAuth", ["login", "password", "encoding"])): + """Http basic authentication helper.""" + + def __new__( + cls, login: str, password: str = "", encoding: str = "latin1" + ) -> "BasicAuth": + if login is None: + raise ValueError("None is not allowed as login value") + + if password is None: + raise ValueError("None is not allowed as password value") + + if ":" in login: + raise ValueError('A ":" is not allowed in login (RFC 1945#section-11.1)') + + return super().__new__(cls, login, password, encoding) + + @classmethod + def decode(cls, auth_header: str, encoding: str = "latin1") -> "BasicAuth": + """Create a BasicAuth object from an Authorization HTTP header.""" + try: + auth_type, encoded_credentials = auth_header.split(" ", 1) + except ValueError: + raise ValueError("Could not parse authorization header.") + + if auth_type.lower() != "basic": + raise ValueError("Unknown authorization method %s" % auth_type) + + try: + decoded = base64.b64decode( + encoded_credentials.encode("ascii"), validate=True + ).decode(encoding) + except binascii.Error: + raise ValueError("Invalid base64 encoding.") + + try: + # RFC 2617 HTTP Authentication + # https://www.ietf.org/rfc/rfc2617.txt + # the colon must be present, but the username and password may be + # otherwise blank. + username, password = decoded.split(":", 1) + except ValueError: + raise ValueError("Invalid credentials.") + + return cls(username, password, encoding=encoding) + + @classmethod + def from_url(cls, url: URL, *, encoding: str = "latin1") -> Optional["BasicAuth"]: + """Create BasicAuth from url.""" + if not isinstance(url, URL): + raise TypeError("url should be yarl.URL instance") + # Check raw_user and raw_password first as yarl is likely + # to already have these values parsed from the netloc in the cache. + if url.raw_user is None and url.raw_password is None: + return None + return cls(url.user or "", url.password or "", encoding=encoding) + + def encode(self) -> str: + """Encode credentials.""" + creds = (f"{self.login}:{self.password}").encode(self.encoding) + return "Basic %s" % base64.b64encode(creds).decode(self.encoding) + + +def strip_auth_from_url(url: URL) -> Tuple[URL, Optional[BasicAuth]]: + """Remove user and password from URL if present and return BasicAuth object.""" + # Check raw_user and raw_password first as yarl is likely + # to already have these values parsed from the netloc in the cache. + if url.raw_user is None and url.raw_password is None: + return url, None + return url.with_user(None), BasicAuth(url.user or "", url.password or "") + + +def netrc_from_env() -> Optional[netrc.netrc]: + """Load netrc from file. + + Attempt to load it from the path specified by the env-var + NETRC or in the default location in the user's home directory. + + Returns None if it couldn't be found or fails to parse. + """ + netrc_env = os.environ.get("NETRC") + + if netrc_env is not None: + netrc_path = Path(netrc_env) + else: + try: + home_dir = Path.home() + except RuntimeError as e: # pragma: no cover + # if pathlib can't resolve home, it may raise a RuntimeError + client_logger.debug( + "Could not resolve home directory when " + "trying to look for .netrc file: %s", + e, + ) + return None + + netrc_path = home_dir / ("_netrc" if IS_WINDOWS else ".netrc") + + try: + return netrc.netrc(str(netrc_path)) + except netrc.NetrcParseError as e: + client_logger.warning("Could not parse .netrc file: %s", e) + except OSError as e: + netrc_exists = False + with contextlib.suppress(OSError): + netrc_exists = netrc_path.is_file() + # we couldn't read the file (doesn't exist, permissions, etc.) + if netrc_env or netrc_exists: + # only warn if the environment wanted us to load it, + # or it appears like the default file does actually exist + client_logger.warning("Could not read .netrc file: %s", e) + + return None + + +@attr.s(auto_attribs=True, frozen=True, slots=True) +class ProxyInfo: + proxy: URL + proxy_auth: Optional[BasicAuth] + + +def basicauth_from_netrc(netrc_obj: Optional[netrc.netrc], host: str) -> BasicAuth: + """ + Return :py:class:`~aiohttp.BasicAuth` credentials for ``host`` from ``netrc_obj``. + + :raises LookupError: if ``netrc_obj`` is :py:data:`None` or if no + entry is found for the ``host``. + """ + if netrc_obj is None: + raise LookupError("No .netrc file found") + auth_from_netrc = netrc_obj.authenticators(host) + + if auth_from_netrc is None: + raise LookupError(f"No entry for {host!s} found in the `.netrc` file.") + login, account, password = auth_from_netrc + + # TODO(PY311): username = login or account + # Up to python 3.10, account could be None if not specified, + # and login will be empty string if not specified. From 3.11, + # login and account will be empty string if not specified. + username = login if (login or account is None) else account + + # TODO(PY311): Remove this, as password will be empty string + # if not specified + if password is None: + password = "" + + return BasicAuth(username, password) + + +def proxies_from_env() -> Dict[str, ProxyInfo]: + proxy_urls = { + k: URL(v) + for k, v in getproxies().items() + if k in ("http", "https", "ws", "wss") + } + netrc_obj = netrc_from_env() + stripped = {k: strip_auth_from_url(v) for k, v in proxy_urls.items()} + ret = {} + for proto, val in stripped.items(): + proxy, auth = val + if proxy.scheme in ("https", "wss"): + client_logger.warning( + "%s proxies %s are not supported, ignoring", proxy.scheme.upper(), proxy + ) + continue + if netrc_obj and auth is None: + if proxy.host is not None: + try: + auth = basicauth_from_netrc(netrc_obj, proxy.host) + except LookupError: + auth = None + ret[proto] = ProxyInfo(proxy, auth) + return ret + + +def get_env_proxy_for_url(url: URL) -> Tuple[URL, Optional[BasicAuth]]: + """Get a permitted proxy for the given URL from the env.""" + if url.host is not None and proxy_bypass(url.host): + raise LookupError(f"Proxying is disallowed for `{url.host!r}`") + + proxies_in_env = proxies_from_env() + try: + proxy_info = proxies_in_env[url.scheme] + except KeyError: + raise LookupError(f"No proxies found for `{url!s}` in the env") + else: + return proxy_info.proxy, proxy_info.proxy_auth + + +@attr.s(auto_attribs=True, frozen=True, slots=True) +class MimeType: + type: str + subtype: str + suffix: str + parameters: "MultiDictProxy[str]" + + +@functools.lru_cache(maxsize=56) +def parse_mimetype(mimetype: str) -> MimeType: + """Parses a MIME type into its components. + + mimetype is a MIME type string. + + Returns a MimeType object. + + Example: + + >>> parse_mimetype('text/html; charset=utf-8') + MimeType(type='text', subtype='html', suffix='', + parameters={'charset': 'utf-8'}) + + """ + if not mimetype: + return MimeType( + type="", subtype="", suffix="", parameters=MultiDictProxy(MultiDict()) + ) + + parts = mimetype.split(";") + params: MultiDict[str] = MultiDict() + for item in parts[1:]: + if not item: + continue + key, _, value = item.partition("=") + params.add(key.lower().strip(), value.strip(' "')) + + fulltype = parts[0].strip().lower() + if fulltype == "*": + fulltype = "*/*" + + mtype, _, stype = fulltype.partition("/") + stype, _, suffix = stype.partition("+") + + return MimeType( + type=mtype, subtype=stype, suffix=suffix, parameters=MultiDictProxy(params) + ) + + +@functools.lru_cache(maxsize=56) +def parse_content_type(raw: str) -> Tuple[str, MappingProxyType[str, str]]: + """Parse Content-Type header. + + Returns a tuple of the parsed content type and a + MappingProxyType of parameters. + """ + msg = HeaderParser().parsestr(f"Content-Type: {raw}") + content_type = msg.get_content_type() + params = msg.get_params(()) + content_dict = dict(params[1:]) # First element is content type again + return content_type, MappingProxyType(content_dict) + + +def guess_filename(obj: Any, default: Optional[str] = None) -> Optional[str]: + name = getattr(obj, "name", None) + if name and isinstance(name, str) and name[0] != "<" and name[-1] != ">": + return Path(name).name + return default + + +not_qtext_re = re.compile(r"[^\041\043-\133\135-\176]") +QCONTENT = {chr(i) for i in range(0x20, 0x7F)} | {"\t"} + + +def quoted_string(content: str) -> str: + """Return 7-bit content as quoted-string. + + Format content into a quoted-string as defined in RFC5322 for + Internet Message Format. Notice that this is not the 8-bit HTTP + format, but the 7-bit email format. Content must be in usascii or + a ValueError is raised. + """ + if not (QCONTENT > set(content)): + raise ValueError(f"bad content for quoted-string {content!r}") + return not_qtext_re.sub(lambda x: "\\" + x.group(0), content) + + +def content_disposition_header( + disptype: str, quote_fields: bool = True, _charset: str = "utf-8", **params: str +) -> str: + """Sets ``Content-Disposition`` header for MIME. + + This is the MIME payload Content-Disposition header from RFC 2183 + and RFC 7579 section 4.2, not the HTTP Content-Disposition from + RFC 6266. + + disptype is a disposition type: inline, attachment, form-data. + Should be valid extension token (see RFC 2183) + + quote_fields performs value quoting to 7-bit MIME headers + according to RFC 7578. Set to quote_fields to False if recipient + can take 8-bit file names and field values. + + _charset specifies the charset to use when quote_fields is True. + + params is a dict with disposition params. + """ + if not disptype or not (TOKEN > set(disptype)): + raise ValueError(f"bad content disposition type {disptype!r}") + + value = disptype + if params: + lparams = [] + for key, val in params.items(): + if not key or not (TOKEN > set(key)): + raise ValueError(f"bad content disposition parameter {key!r}={val!r}") + if quote_fields: + if key.lower() == "filename": + qval = quote(val, "", encoding=_charset) + lparams.append((key, '"%s"' % qval)) + else: + try: + qval = quoted_string(val) + except ValueError: + qval = "".join( + (_charset, "''", quote(val, "", encoding=_charset)) + ) + lparams.append((key + "*", qval)) + else: + lparams.append((key, '"%s"' % qval)) + else: + qval = val.replace("\\", "\\\\").replace('"', '\\"') + lparams.append((key, '"%s"' % qval)) + sparams = "; ".join("=".join(pair) for pair in lparams) + value = "; ".join((value, sparams)) + return value + + +def is_ip_address(host: Optional[str]) -> bool: + """Check if host looks like an IP Address. + + This check is only meant as a heuristic to ensure that + a host is not a domain name. + """ + if not host: + return False + # For a host to be an ipv4 address, it must be all numeric. + # The host must contain a colon to be an IPv6 address. + return ":" in host or host.replace(".", "").isdigit() + + +_cached_current_datetime: Optional[int] = None +_cached_formatted_datetime = "" + + +def rfc822_formatted_time() -> str: + global _cached_current_datetime + global _cached_formatted_datetime + + now = int(time.time()) + if now != _cached_current_datetime: + # Weekday and month names for HTTP date/time formatting; + # always English! + # Tuples are constants stored in codeobject! + _weekdayname = ("Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun") + _monthname = ( + "", # Dummy so we can use 1-based month numbers + "Jan", + "Feb", + "Mar", + "Apr", + "May", + "Jun", + "Jul", + "Aug", + "Sep", + "Oct", + "Nov", + "Dec", + ) + + year, month, day, hh, mm, ss, wd, *tail = time.gmtime(now) + _cached_formatted_datetime = "%s, %02d %3s %4d %02d:%02d:%02d GMT" % ( + _weekdayname[wd], + day, + _monthname[month], + year, + hh, + mm, + ss, + ) + _cached_current_datetime = now + return _cached_formatted_datetime + + +def _weakref_handle(info: "Tuple[weakref.ref[object], str]") -> None: + ref, name = info + ob = ref() + if ob is not None: + with suppress(Exception): + getattr(ob, name)() + + +def weakref_handle( + ob: object, + name: str, + timeout: float, + loop: asyncio.AbstractEventLoop, + timeout_ceil_threshold: float = 5, +) -> Optional[asyncio.TimerHandle]: + if timeout is not None and timeout > 0: + when = loop.time() + timeout + if timeout >= timeout_ceil_threshold: + when = ceil(when) + + return loop.call_at(when, _weakref_handle, (weakref.ref(ob), name)) + return None + + +def call_later( + cb: Callable[[], Any], + timeout: float, + loop: asyncio.AbstractEventLoop, + timeout_ceil_threshold: float = 5, +) -> Optional[asyncio.TimerHandle]: + if timeout is None or timeout <= 0: + return None + now = loop.time() + when = calculate_timeout_when(now, timeout, timeout_ceil_threshold) + return loop.call_at(when, cb) + + +def calculate_timeout_when( + loop_time: float, + timeout: float, + timeout_ceiling_threshold: float, +) -> float: + """Calculate when to execute a timeout.""" + when = loop_time + timeout + if timeout > timeout_ceiling_threshold: + return ceil(when) + return when + + +class TimeoutHandle: + """Timeout handle""" + + __slots__ = ("_timeout", "_loop", "_ceil_threshold", "_callbacks") + + def __init__( + self, + loop: asyncio.AbstractEventLoop, + timeout: Optional[float], + ceil_threshold: float = 5, + ) -> None: + self._timeout = timeout + self._loop = loop + self._ceil_threshold = ceil_threshold + self._callbacks: List[ + Tuple[Callable[..., None], Tuple[Any, ...], Dict[str, Any]] + ] = [] + + def register( + self, callback: Callable[..., None], *args: Any, **kwargs: Any + ) -> None: + self._callbacks.append((callback, args, kwargs)) + + def close(self) -> None: + self._callbacks.clear() + + def start(self) -> Optional[asyncio.TimerHandle]: + timeout = self._timeout + if timeout is not None and timeout > 0: + when = self._loop.time() + timeout + if timeout >= self._ceil_threshold: + when = ceil(when) + return self._loop.call_at(when, self.__call__) + else: + return None + + def timer(self) -> "BaseTimerContext": + if self._timeout is not None and self._timeout > 0: + timer = TimerContext(self._loop) + self.register(timer.timeout) + return timer + else: + return TimerNoop() + + def __call__(self) -> None: + for cb, args, kwargs in self._callbacks: + with suppress(Exception): + cb(*args, **kwargs) + + self._callbacks.clear() + + +class BaseTimerContext(ContextManager["BaseTimerContext"]): + + __slots__ = () + + def assert_timeout(self) -> None: + """Raise TimeoutError if timeout has been exceeded.""" + + +class TimerNoop(BaseTimerContext): + + __slots__ = () + + def __enter__(self) -> BaseTimerContext: + return self + + def __exit__( + self, + exc_type: Optional[Type[BaseException]], + exc_val: Optional[BaseException], + exc_tb: Optional[TracebackType], + ) -> None: + return + + +class TimerContext(BaseTimerContext): + """Low resolution timeout context manager""" + + __slots__ = ("_loop", "_tasks", "_cancelled", "_cancelling") + + def __init__(self, loop: asyncio.AbstractEventLoop) -> None: + self._loop = loop + self._tasks: List[asyncio.Task[Any]] = [] + self._cancelled = False + self._cancelling = 0 + + def assert_timeout(self) -> None: + """Raise TimeoutError if timer has already been cancelled.""" + if self._cancelled: + raise asyncio.TimeoutError from None + + def __enter__(self) -> BaseTimerContext: + task = asyncio.current_task(loop=self._loop) + if task is None: + raise RuntimeError("Timeout context manager should be used inside a task") + + if sys.version_info >= (3, 11): + # Remember if the task was already cancelling + # so when we __exit__ we can decide if we should + # raise asyncio.TimeoutError or let the cancellation propagate + self._cancelling = task.cancelling() + + if self._cancelled: + raise asyncio.TimeoutError from None + + self._tasks.append(task) + return self + + def __exit__( + self, + exc_type: Optional[Type[BaseException]], + exc_val: Optional[BaseException], + exc_tb: Optional[TracebackType], + ) -> Optional[bool]: + enter_task: Optional[asyncio.Task[Any]] = None + if self._tasks: + enter_task = self._tasks.pop() + + if exc_type is asyncio.CancelledError and self._cancelled: + assert enter_task is not None + # The timeout was hit, and the task was cancelled + # so we need to uncancel the last task that entered the context manager + # since the cancellation should not leak out of the context manager + if sys.version_info >= (3, 11): + # If the task was already cancelling don't raise + # asyncio.TimeoutError and instead return None + # to allow the cancellation to propagate + if enter_task.uncancel() > self._cancelling: + return None + raise asyncio.TimeoutError from exc_val + return None + + def timeout(self) -> None: + if not self._cancelled: + for task in set(self._tasks): + task.cancel() + + self._cancelled = True + + +def ceil_timeout( + delay: Optional[float], ceil_threshold: float = 5 +) -> async_timeout.Timeout: + if delay is None or delay <= 0: + return async_timeout.timeout(None) + + loop = asyncio.get_running_loop() + now = loop.time() + when = now + delay + if delay > ceil_threshold: + when = ceil(when) + return async_timeout.timeout_at(when) + + +class HeadersMixin: + """Mixin for handling headers.""" + + ATTRS = frozenset(["_content_type", "_content_dict", "_stored_content_type"]) + + _headers: MultiMapping[str] + _content_type: Optional[str] = None + _content_dict: Optional[Dict[str, str]] = None + _stored_content_type: Union[str, None, _SENTINEL] = sentinel + + def _parse_content_type(self, raw: Optional[str]) -> None: + self._stored_content_type = raw + if raw is None: + # default value according to RFC 2616 + self._content_type = "application/octet-stream" + self._content_dict = {} + else: + content_type, content_mapping_proxy = parse_content_type(raw) + self._content_type = content_type + # _content_dict needs to be mutable so we can update it + self._content_dict = content_mapping_proxy.copy() + + @property + def content_type(self) -> str: + """The value of content part for Content-Type HTTP header.""" + raw = self._headers.get(hdrs.CONTENT_TYPE) + if self._stored_content_type != raw: + self._parse_content_type(raw) + assert self._content_type is not None + return self._content_type + + @property + def charset(self) -> Optional[str]: + """The value of charset part for Content-Type HTTP header.""" + raw = self._headers.get(hdrs.CONTENT_TYPE) + if self._stored_content_type != raw: + self._parse_content_type(raw) + assert self._content_dict is not None + return self._content_dict.get("charset") + + @property + def content_length(self) -> Optional[int]: + """The value of Content-Length HTTP header.""" + content_length = self._headers.get(hdrs.CONTENT_LENGTH) + return None if content_length is None else int(content_length) + + +def set_result(fut: "asyncio.Future[_T]", result: _T) -> None: + if not fut.done(): + fut.set_result(result) + + +_EXC_SENTINEL = BaseException() + + +class ErrorableProtocol(Protocol): + def set_exception( + self, + exc: BaseException, + exc_cause: BaseException = ..., + ) -> None: ... # pragma: no cover + + +def set_exception( + fut: "asyncio.Future[_T] | ErrorableProtocol", + exc: BaseException, + exc_cause: BaseException = _EXC_SENTINEL, +) -> None: + """Set future exception. + + If the future is marked as complete, this function is a no-op. + + :param exc_cause: An exception that is a direct cause of ``exc``. + Only set if provided. + """ + if asyncio.isfuture(fut) and fut.done(): + return + + exc_is_sentinel = exc_cause is _EXC_SENTINEL + exc_causes_itself = exc is exc_cause + if not exc_is_sentinel and not exc_causes_itself: + exc.__cause__ = exc_cause + + fut.set_exception(exc) + + +@functools.total_ordering +class AppKey(Generic[_T]): + """Keys for static typing support in Application.""" + + __slots__ = ("_name", "_t", "__orig_class__") + + # This may be set by Python when instantiating with a generic type. We need to + # support this, in order to support types that are not concrete classes, + # like Iterable, which can't be passed as the second parameter to __init__. + __orig_class__: Type[object] + + def __init__(self, name: str, t: Optional[Type[_T]] = None): + # Prefix with module name to help deduplicate key names. + frame = inspect.currentframe() + while frame: + if frame.f_code.co_name == "<module>": + module: str = frame.f_globals["__name__"] + break + frame = frame.f_back + + self._name = module + "." + name + self._t = t + + def __lt__(self, other: object) -> bool: + if isinstance(other, AppKey): + return self._name < other._name + return True # Order AppKey above other types. + + def __repr__(self) -> str: + t = self._t + if t is None: + with suppress(AttributeError): + # Set to type arg. + t = get_args(self.__orig_class__)[0] + + if t is None: + t_repr = "<<Unknown>>" + elif isinstance(t, type): + if t.__module__ == "builtins": + t_repr = t.__qualname__ + else: + t_repr = f"{t.__module__}.{t.__qualname__}" + else: + t_repr = repr(t) + return f"<AppKey({self._name}, type={t_repr})>" + + +class ChainMapProxy(Mapping[Union[str, AppKey[Any]], Any]): + __slots__ = ("_maps",) + + def __init__(self, maps: Iterable[Mapping[Union[str, AppKey[Any]], Any]]) -> None: + self._maps = tuple(maps) + + def __init_subclass__(cls) -> None: + raise TypeError( + "Inheritance class {} from ChainMapProxy " + "is forbidden".format(cls.__name__) + ) + + @overload # type: ignore[override] + def __getitem__(self, key: AppKey[_T]) -> _T: ... + + @overload + def __getitem__(self, key: str) -> Any: ... + + def __getitem__(self, key: Union[str, AppKey[_T]]) -> Any: + for mapping in self._maps: + try: + return mapping[key] + except KeyError: + pass + raise KeyError(key) + + @overload # type: ignore[override] + def get(self, key: AppKey[_T], default: _S) -> Union[_T, _S]: ... + + @overload + def get(self, key: AppKey[_T], default: None = ...) -> Optional[_T]: ... + + @overload + def get(self, key: str, default: Any = ...) -> Any: ... + + def get(self, key: Union[str, AppKey[_T]], default: Any = None) -> Any: + try: + return self[key] + except KeyError: + return default + + def __len__(self) -> int: + # reuses stored hash values if possible + return len(set().union(*self._maps)) + + def __iter__(self) -> Iterator[Union[str, AppKey[Any]]]: + d: Dict[Union[str, AppKey[Any]], Any] = {} + for mapping in reversed(self._maps): + # reuses stored hash values if possible + d.update(mapping) + return iter(d) + + def __contains__(self, key: object) -> bool: + return any(key in m for m in self._maps) + + def __bool__(self) -> bool: + return any(self._maps) + + def __repr__(self) -> str: + content = ", ".join(map(repr, self._maps)) + return f"ChainMapProxy({content})" + + +# https://tools.ietf.org/html/rfc7232#section-2.3 +_ETAGC = r"[!\x23-\x7E\x80-\xff]+" +_ETAGC_RE = re.compile(_ETAGC) +_QUOTED_ETAG = rf'(W/)?"({_ETAGC})"' +QUOTED_ETAG_RE = re.compile(_QUOTED_ETAG) +LIST_QUOTED_ETAG_RE = re.compile(rf"({_QUOTED_ETAG})(?:\s*,\s*|$)|(.)") + +ETAG_ANY = "*" + + +@attr.s(auto_attribs=True, frozen=True, slots=True) +class ETag: + value: str + is_weak: bool = False + + +def validate_etag_value(value: str) -> None: + if value != ETAG_ANY and not _ETAGC_RE.fullmatch(value): + raise ValueError( + f"Value {value!r} is not a valid etag. Maybe it contains '\"'?" + ) + + +def parse_http_date(date_str: Optional[str]) -> Optional[datetime.datetime]: + """Process a date string, return a datetime object""" + if date_str is not None: + timetuple = parsedate(date_str) + if timetuple is not None: + with suppress(ValueError): + return datetime.datetime(*timetuple[:6], tzinfo=datetime.timezone.utc) + return None + + +@functools.lru_cache +def must_be_empty_body(method: str, code: int) -> bool: + """Check if a request must return an empty body.""" + return ( + code in EMPTY_BODY_STATUS_CODES + or method in EMPTY_BODY_METHODS + or (200 <= code < 300 and method in hdrs.METH_CONNECT_ALL) + ) + + +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 EMPTY_BODY_STATUS_CODES or ( + 200 <= code < 300 and method in hdrs.METH_CONNECT_ALL + ) |