venv/lib/python3.11/site-packages/werkzeug/datastructures/etag.py

   1 from __future__ import annotations
   2
   3 from collections.abc import Collection
   4
   5
   6 class ETags(Collection):
   7     """A set that can be used to check if one etag is present in a collection
   8     of etags.
   9     """
  10
  11     def __init__(self, strong_etags=None, weak_etags=None, star_tag=False):
  12         if not star_tag and strong_etags:
  13             self._strong = frozenset(strong_etags)
  14         else:
  15             self._strong = frozenset()
  16
  17         self._weak = frozenset(weak_etags or ())
  18         self.star_tag = star_tag
  19
  20     def as_set(self, include_weak=False):
  21         """Convert the `ETags` object into a python set.  Per default all the
  22         weak etags are not part of this set."""
  23         rv = set(self._strong)
  24         if include_weak:
  25             rv.update(self._weak)
  26         return rv
  27
  28     def is_weak(self, etag):
  29         """Check if an etag is weak."""
  30         return etag in self._weak
  31
  32     def is_strong(self, etag):
  33         """Check if an etag is strong."""
  34         return etag in self._strong
  35
  36     def contains_weak(self, etag):
  37         """Check if an etag is part of the set including weak and strong tags."""
  38         return self.is_weak(etag) or self.contains(etag)
  39
  40     def contains(self, etag):
  41         """Check if an etag is part of the set ignoring weak tags.
  42         It is also possible to use the ``in`` operator.
  43         """
  44         if self.star_tag:
  45             return True
  46         return self.is_strong(etag)
  47
  48     def contains_raw(self, etag):
  49         """When passed a quoted tag it will check if this tag is part of the
  50         set.  If the tag is weak it is checked against weak and strong tags,
  51         otherwise strong only."""
  52         from ..http import unquote_etag
  53
  54         etag, weak = unquote_etag(etag)
  55         if weak:
  56             return self.contains_weak(etag)
  57         return self.contains(etag)
  58
  59     def to_header(self):
  60         """Convert the etags set into a HTTP header string."""
  61         if self.star_tag:
  62             return "*"
  63         return ", ".join(
  64             [f'"{x}"' for x in self._strong] + [f'W/"{x}"' for x in self._weak]
  65         )
  66
  67     def __call__(self, etag=None, data=None, include_weak=False):
  68         if [etag, data].count(None) != 1:
  69             raise TypeError("either tag or data required, but at least one")
  70         if etag is None:
  71             from ..http import generate_etag
  72
  73             etag = generate_etag(data)
  74         if include_weak:
  75             if etag in self._weak:
  76                 return True
  77         return etag in self._strong
  78
  79     def __bool__(self):
  80         return bool(self.star_tag or self._strong or self._weak)
  81
  82     def __str__(self):
  83         return self.to_header()
  84
  85     def __len__(self):
  86         return len(self._strong)
  87
  88     def __iter__(self):
  89         return iter(self._strong)
  90
  91     def __contains__(self, etag):
  92         return self.contains(etag)
  93
  94     def __repr__(self):
  95         return f"<{type(self).__name__} {str(self)!r}>"