63 lines
1.8 KiB
Python
63 lines
1.8 KiB
Python
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# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
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import collections.abc
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from typing import Any
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from dns._immutable_ctx import immutable
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@immutable
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class Dict(collections.abc.Mapping): # lgtm[py/missing-equals]
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def __init__(self, dictionary: Any, no_copy: bool = False):
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"""Make an immutable dictionary from the specified dictionary.
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If *no_copy* is `True`, then *dictionary* will be wrapped instead
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of copied. Only set this if you are sure there will be no external
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references to the dictionary.
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"""
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if no_copy and isinstance(dictionary, dict):
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self._odict = dictionary
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else:
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self._odict = dict(dictionary)
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self._hash = None
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def __getitem__(self, key):
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return self._odict.__getitem__(key)
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def __hash__(self): # pylint: disable=invalid-hash-returned
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if self._hash is None:
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h = 0
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for key in sorted(self._odict.keys()):
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h ^= hash(key)
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object.__setattr__(self, "_hash", h)
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# this does return an int, but pylint doesn't figure that out
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return self._hash
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def __len__(self):
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return len(self._odict)
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def __iter__(self):
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return iter(self._odict)
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def constify(o: Any) -> Any:
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"""
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Convert mutable types to immutable types.
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"""
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if isinstance(o, bytearray):
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return bytes(o)
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if isinstance(o, tuple):
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try:
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hash(o)
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return o
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except Exception:
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return tuple(constify(elt) for elt in o)
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if isinstance(o, list):
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return tuple(constify(elt) for elt in o)
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if isinstance(o, dict):
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cdict = dict()
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for k, v in o.items():
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cdict[k] = constify(v)
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return Dict(cdict, True)
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return o
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