JezK
Edit File: http.py
import re import typing as t from datetime import datetime from .._internal import _cookie_parse_impl from .._internal import _dt_as_utc from .._internal import _to_str from ..http import generate_etag from ..http import parse_date from ..http import parse_etags from ..http import parse_if_range_header from ..http import unquote_etag _etag_re = re.compile(r'([Ww]/)?(?:"(.*?)"|(.*?))(?:\s*,\s*|$)') def is_resource_modified( http_range: t.Optional[str] = None, http_if_range: t.Optional[str] = None, http_if_modified_since: t.Optional[str] = None, http_if_none_match: t.Optional[str] = None, http_if_match: t.Optional[str] = None, etag: t.Optional[str] = None, data: t.Optional[bytes] = None, last_modified: t.Optional[t.Union[datetime, str]] = None, ignore_if_range: bool = True, ) -> bool: """Convenience method for conditional requests. :param http_range: Range HTTP header :param http_if_range: If-Range HTTP header :param http_if_modified_since: If-Modified-Since HTTP header :param http_if_none_match: If-None-Match HTTP header :param http_if_match: If-Match HTTP header :param etag: the etag for the response for comparison. :param data: or alternatively the data of the response to automatically generate an etag using :func:`generate_etag`. :param last_modified: an optional date of the last modification. :param ignore_if_range: If `False`, `If-Range` header will be taken into account. :return: `True` if the resource was modified, otherwise `False`. .. versionadded:: 2.2 """ if etag is None and data is not None: etag = generate_etag(data) elif data is not None: raise TypeError("both data and etag given") unmodified = False if isinstance(last_modified, str): last_modified = parse_date(last_modified) # HTTP doesn't use microsecond, remove it to avoid false positive # comparisons. Mark naive datetimes as UTC. if last_modified is not None: last_modified = _dt_as_utc(last_modified.replace(microsecond=0)) if_range = None if not ignore_if_range and http_range is not None: # https://tools.ietf.org/html/rfc7233#section-3.2 # A server MUST ignore an If-Range header field received in a request # that does not contain a Range header field. if_range = parse_if_range_header(http_if_range) if if_range is not None and if_range.date is not None: modified_since: t.Optional[datetime] = if_range.date else: modified_since = parse_date(http_if_modified_since) if modified_since and last_modified and last_modified <= modified_since: unmodified = True if etag: etag, _ = unquote_etag(etag) etag = t.cast(str, etag) if if_range is not None and if_range.etag is not None: unmodified = parse_etags(if_range.etag).contains(etag) else: if_none_match = parse_etags(http_if_none_match) if if_none_match: # https://tools.ietf.org/html/rfc7232#section-3.2 # "A recipient MUST use the weak comparison function when comparing # entity-tags for If-None-Match" unmodified = if_none_match.contains_weak(etag) # https://tools.ietf.org/html/rfc7232#section-3.1 # "Origin server MUST use the strong comparison function when # comparing entity-tags for If-Match" if_match = parse_etags(http_if_match) if if_match: unmodified = not if_match.is_strong(etag) return not unmodified def parse_cookie( cookie: t.Union[bytes, str, None] = "", charset: str = "utf-8", errors: str = "replace", cls: t.Optional[t.Type["ds.MultiDict"]] = None, ) -> "ds.MultiDict[str, str]": """Parse a cookie from a string. The same key can be provided multiple times, the values are stored in-order. The default :class:`MultiDict` will have the first value first, and all values can be retrieved with :meth:`MultiDict.getlist`. :param cookie: The cookie header as a string. :param charset: The charset for the cookie values. :param errors: The error behavior for the charset decoding. :param cls: A dict-like class to store the parsed cookies in. Defaults to :class:`MultiDict`. .. versionadded:: 2.2 """ # PEP 3333 sends headers through the environ as latin1 decoded # strings. Encode strings back to bytes for parsing. if isinstance(cookie, str): cookie = cookie.encode("latin1", "replace") if cls is None: cls = ds.MultiDict def _parse_pairs() -> t.Iterator[t.Tuple[str, str]]: for key, val in _cookie_parse_impl(cookie): # type: ignore key_str = _to_str(key, charset, errors, allow_none_charset=True) val_str = _to_str(val, charset, errors, allow_none_charset=True) yield key_str, val_str return cls(_parse_pairs()) # circular dependencies from .. import datastructures as ds