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Diffstat (limited to 'src/leap/util/dicts.py')
| -rw-r--r-- | src/leap/util/dicts.py | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/src/leap/util/dicts.py b/src/leap/util/dicts.py new file mode 100644 index 00000000..d8177973 --- /dev/null +++ b/src/leap/util/dicts.py @@ -0,0 +1,258 @@ +# Backport of OrderedDict() class that runs on Python 2.4, 2.5, 2.6, 2.7 and pypy. +# Passes Python2.7's test suite and incorporates all the latest updates. + +try: + from thread import get_ident as _get_ident +except ImportError: + from dummy_thread import get_ident as _get_ident + +try: + from _abcoll import KeysView, ValuesView, ItemsView +except ImportError: + pass + + +class OrderedDict(dict): + 'Dictionary that remembers insertion order' + # An inherited dict maps keys to values. + # The inherited dict provides __getitem__, __len__, __contains__, and get. + # The remaining methods are order-aware. + # Big-O running times for all methods are the same as for regular dictionaries. + + # The internal self.__map dictionary maps keys to links in a doubly linked list. + # The circular doubly linked list starts and ends with a sentinel element. + # The sentinel element never gets deleted (this simplifies the algorithm). + # Each link is stored as a list of length three: [PREV, NEXT, KEY]. + + def __init__(self, *args, **kwds): + '''Initialize an ordered dictionary. Signature is the same as for + regular dictionaries, but keyword arguments are not recommended + because their insertion order is arbitrary. + + ''' + if len(args) > 1: + raise TypeError('expected at most 1 arguments, got %d' % len(args)) + try: + self.__root + except AttributeError: + self.__root = root = [] # sentinel node + root[:] = [root, root, None] + self.__map = {} + self.__update(*args, **kwds) + + def __setitem__(self, key, value, dict_setitem=dict.__setitem__): + 'od.__setitem__(i, y) <==> od[i]=y' + # Setting a new item creates a new link which goes at the end of the linked + # list, and the inherited dictionary is updated with the new key/value pair. + if key not in self: + root = self.__root + last = root[0] + last[1] = root[0] = self.__map[key] = [last, root, key] + dict_setitem(self, key, value) + + def __delitem__(self, key, dict_delitem=dict.__delitem__): + 'od.__delitem__(y) <==> del od[y]' + # Deleting an existing item uses self.__map to find the link which is + # then removed by updating the links in the predecessor and successor nodes. + dict_delitem(self, key) + link_prev, link_next, key = self.__map.pop(key) + link_prev[1] = link_next + link_next[0] = link_prev + + def __iter__(self): + 'od.__iter__() <==> iter(od)' + root = self.__root + curr = root[1] + while curr is not root: + yield curr[2] + curr = curr[1] + + def __reversed__(self): + 'od.__reversed__() <==> reversed(od)' + root = self.__root + curr = root[0] + while curr is not root: + yield curr[2] + curr = curr[0] + + def clear(self): + 'od.clear() -> None. Remove all items from od.' + try: + for node in self.__map.itervalues(): + del node[:] + root = self.__root + root[:] = [root, root, None] + self.__map.clear() + except AttributeError: + pass + dict.clear(self) + + def popitem(self, last=True): + '''od.popitem() -> (k, v), return and remove a (key, value) pair. + Pairs are returned in LIFO order if last is true or FIFO order if false. + + ''' + if not self: + raise KeyError('dictionary is empty') + root = self.__root + if last: + link = root[0] + link_prev = link[0] + link_prev[1] = root + root[0] = link_prev + else: + link = root[1] + link_next = link[1] + root[1] = link_next + link_next[0] = root + key = link[2] + del self.__map[key] + value = dict.pop(self, key) + return key, value + + # -- the following methods do not depend on the internal structure -- + + def keys(self): + 'od.keys() -> list of keys in od' + return list(self) + + def values(self): + 'od.values() -> list of values in od' + return [self[key] for key in self] + + def items(self): + 'od.items() -> list of (key, value) pairs in od' + return [(key, self[key]) for key in self] + + def iterkeys(self): + 'od.iterkeys() -> an iterator over the keys in od' + return iter(self) + + def itervalues(self): + 'od.itervalues -> an iterator over the values in od' + for k in self: + yield self[k] + + def iteritems(self): + 'od.iteritems -> an iterator over the (key, value) items in od' + for k in self: + yield (k, self[k]) + + def update(*args, **kwds): + '''od.update(E, **F) -> None. Update od from dict/iterable E and F. + + If E is a dict instance, does: for k in E: od[k] = E[k] + If E has a .keys() method, does: for k in E.keys(): od[k] = E[k] + Or if E is an iterable of items, does: for k, v in E: od[k] = v + In either case, this is followed by: for k, v in F.items(): od[k] = v + + ''' + if len(args) > 2: + raise TypeError('update() takes at most 2 positional ' + 'arguments (%d given)' % (len(args),)) + elif not args: + raise TypeError('update() takes at least 1 argument (0 given)') + self = args[0] + # Make progressively weaker assumptions about "other" + other = () + if len(args) == 2: + other = args[1] + if isinstance(other, dict): + for key in other: + self[key] = other[key] + elif hasattr(other, 'keys'): + for key in other.keys(): + self[key] = other[key] + else: + for key, value in other: + self[key] = value + for key, value in kwds.items(): + self[key] = value + + __update = update # let subclasses override update without breaking __init__ + + __marker = object() + + def pop(self, key, default=__marker): + '''od.pop(k[,d]) -> v, remove specified key and return the corresponding value. + If key is not found, d is returned if given, otherwise KeyError is raised. + + ''' + if key in self: + result = self[key] + del self[key] + return result + if default is self.__marker: + raise KeyError(key) + return default + + def setdefault(self, key, default=None): + 'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od' + if key in self: + return self[key] + self[key] = default + return default + + def __repr__(self, _repr_running={}): + 'od.__repr__() <==> repr(od)' + call_key = id(self), _get_ident() + if call_key in _repr_running: + return '...' + _repr_running[call_key] = 1 + try: + if not self: + return '%s()' % (self.__class__.__name__,) + return '%s(%r)' % (self.__class__.__name__, self.items()) + finally: + del _repr_running[call_key] + + def __reduce__(self): + 'Return state information for pickling' + items = [[k, self[k]] for k in self] + inst_dict = vars(self).copy() + for k in vars(OrderedDict()): + inst_dict.pop(k, None) + if inst_dict: + return (self.__class__, (items,), inst_dict) + return self.__class__, (items,) + + def copy(self): + 'od.copy() -> a shallow copy of od' + return self.__class__(self) + + @classmethod + def fromkeys(cls, iterable, value=None): + '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S + and values equal to v (which defaults to None). + + ''' + d = cls() + for key in iterable: + d[key] = value + return d + + def __eq__(self, other): + '''od.__eq__(y) <==> od==y. Comparison to another OD is order-sensitive + while comparison to a regular mapping is order-insensitive. + + ''' + if isinstance(other, OrderedDict): + return len(self)==len(other) and self.items() == other.items() + return dict.__eq__(self, other) + + def __ne__(self, other): + return not self == other + + # -- the following methods are only used in Python 2.7 -- + + def viewkeys(self): + "od.viewkeys() -> a set-like object providing a view on od's keys" + return KeysView(self) + + def viewvalues(self): + "od.viewvalues() -> an object providing a view on od's values" + return ValuesView(self) + + def viewitems(self): + "od.viewitems() -> a set-like object providing a view on od's items" + return ItemsView(self) |