def make_etag(value, is_weak=False):
"""Creates and returns a ETag object.
Args:
value (str): Unquated entity tag value
is_weak (bool): The weakness indicator
Returns:
A ``str``-like Etag instance with weakness indicator.
"""
etag = ETag(value)
etag.is_weak = is_weak
return etag
def _parse_etags(etag_str):
"""Parse a string containing one or more HTTP entity-tags.
The string is assumed to be formatted as defined for a precondition
header, and may contain either a single ETag, or multiple comma-separated
ETags. The string may also contain a '*' character, in order to indicate
that any ETag should match the precondition.
(See also: RFC 7232, Section 3)
Args:
etag_str (str): An ASCII header value to parse ETags from. ETag values
within may be prefixed by ``W/`` to indicate that the weak comparison
function should be used.
Returns:
list: A list of unquoted ETags or ``['*']`` if all ETags should be
matched. If the string to be parse is empty, or contains only
whitespace, ``None`` will be returned instead.
"""
etag_str = etag_str.strip()
if not etag_str:
return None
if etag_str == '*':
return [etag_str]
if ',' not in etag_str:
return [ETag.loads(etag_str)]
etags = []
# PERF(kgriffs): Parsing out the weak string like this turns out to be more
# performant than grabbing the entire entity-tag and passing it to
# ETag.loads(). This is also faster than parsing etag_str manually via
# str.find() and slicing.
for weak, value in _ENTITY_TAG_PATTERN.findall(etag_str):
t = ETag(value)
t.is_weak = bool(weak)
etags.append(t)
# NOTE(kgriffs): Normalize a string with only whitespace and commas
# to None, since it is like a list of individual ETag headers that
# are all set to nothing, and so therefore basically should be
# treated as not having been set in the first place.
return etags or None
def _parse_etags(etag_str):
"""Parse a string containing one or more HTTP entity-tags.
The string is assumed to be formatted as defined for a precondition
header, and may contain either a single ETag, or multiple comma-separated
ETags. The string may also contain a '*' character, in order to indicate
that any ETag should match the precondition.
(See also: RFC 7232, Section 3)
Args:
etag_str (str): An ASCII header value to parse ETags from. ETag values
within may be prefixed by ``W/`` to indicate that the weak comparison
function should be used.
Returns:
list: A list of unquoted ETags or ``['*']`` if all ETags should be
matched. If the string to be parse is empty, or contains only
whitespace, ``None`` will be returned instead.
"""
etag_str = etag_str.strip()
if not etag_str:
return None
if etag_str == '*':
return [etag_str]
if ',' not in etag_str:
return [ETag.loads(etag_str)]
etags = []
# PERF(kgriffs): Parsing out the weak string like this turns out to be more
# performant than grabbing the entire entity-tag and passing it to
# ETag.loads(). This is also faster than parsing etag_str manually via
# str.find() and slicing.
for weak, value in _ENTITY_TAG_PATTERN.findall(etag_str):
t = ETag(value)
t.is_weak = bool(weak)
etags.append(t)
# NOTE(kgriffs): Normalize a string with only whitespace and commas
# to None, since it is like a list of individual ETag headers that
# are all set to nothing, and so therefore basically should be
# treated as not having been set in the first place.
return etags or None