codekingpro/portable-devtools

1# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license2 3import collections.abc4from typing import Any, Callable5 6from dns._immutable_ctx import immutable7 8 9@immutable10class Dict(collections.abc.Mapping):  # lgtm[py/missing-equals]11    def __init__(12        self,13        dictionary: Any,14        no_copy: bool = False,15        map_factory: Callable[[], collections.abc.MutableMapping] = dict,16    ):17        """Make an immutable dictionary from the specified dictionary.18 19        If *no_copy* is `True`, then *dictionary* will be wrapped instead20        of copied.  Only set this if you are sure there will be no external21        references to the dictionary.22        """23        if no_copy and isinstance(dictionary, collections.abc.MutableMapping):24            self._odict = dictionary25        else:26            self._odict = map_factory()27            self._odict.update(dictionary)28        self._hash = None29 30    def __getitem__(self, key):31        return self._odict.__getitem__(key)32 33    def __hash__(self):  # pylint: disable=invalid-hash-returned34        if self._hash is None:35            h = 036            for key in sorted(self._odict.keys()):37                h ^= hash(key)38            object.__setattr__(self, "_hash", h)39        # this does return an int, but pylint doesn't figure that out40        return self._hash41 42    def __len__(self):43        return len(self._odict)44 45    def __iter__(self):46        return iter(self._odict)47 48 49def constify(o: Any) -> Any:50    """51    Convert mutable types to immutable types.52    """53    if isinstance(o, bytearray):54        return bytes(o)55    if isinstance(o, tuple):56        try:57            hash(o)58            return o59        except Exception:60            return tuple(constify(elt) for elt in o)61    if isinstance(o, list):62        return tuple(constify(elt) for elt in o)63    if isinstance(o, dict):64        cdict = dict()65        for k, v in o.items():66            cdict[k] = constify(v)67        return Dict(cdict, True)68    return o69