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# Copyright 2013, Big Switch Networks, Inc.
#
# LoxiGen is licensed under the Eclipse Public License, version 1.0 (EPL), with
# the following special exception:
#
# LOXI Exception
#
# As a special exception to the terms of the EPL, you may distribute libraries
# generated by LoxiGen (LoxiGen Libraries) under the terms of your choice, provided
# that copyright and licensing notices generated by LoxiGen are not altered or removed
# from the LoxiGen Libraries and the notice provided below is (i) included in
# the LoxiGen Libraries, if distributed in source code form and (ii) included in any
# documentation for the LoxiGen Libraries, if distributed in binary form.
#
# Notice: "Copyright 2013, Big Switch Networks, Inc. This library was generated by the LoxiGen Compiler."
#
# You may not use this file except in compliance with the EPL or LOXI Exception. You may obtain
# a copy of the EPL at:
#
# http://www.eclipse.org/legal/epl-v10.html
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# EPL for the specific language governing permissions and limitations
# under the EPL.
"""
@brief Generic utilities
Intended to be imported into another namespace
"""
import logging
import collections
import functools
import sys
################################################################
#
# Debug
#
################################################################
def debug(obj):
"""
Legacy logging method. Delegate to logging.debug.
Use logging.debug directly in the future.S
"""
logging.debug(obj)
def log(obj):
"""
Legacy logging method. Delegate to logging.info.
Use logging.info directly in the future.S
"""
logging.info(obj)
################################################################
#
# Memoize
#
################################################################
def memoize(obj):
""" A function/method decorator that memoizes the result"""
cache = obj.cache = {}
@functools.wraps(obj)
def memoizer(*args, **kwargs):
key = args + tuple(kwargs.items())
if key not in cache:
cache[key] = obj(*args, **kwargs)
return cache[key]
return memoizer
################################################################
#
# OrderedSet
#
################################################################
class OrderedSet(collections.MutableSet):
"""
A set implementations that retains insertion order. From the receipe
http://code.activestate.com/recipes/576694/
as referred to in the python documentation
"""
def __init__(self, iterable=None):
self.end = end = []
end += [None, end, end] # sentinel node for doubly linked list
self.map = {} # key --> [key, prev, next]
if iterable is not None:
self |= iterable
def __len__(self):
return len(self.map)
def __contains__(self, key):
return key in self.map
def add(self, key):
if key not in self.map:
end = self.end
curr = end[1]
curr[2] = end[1] = self.map[key] = [key, curr, end]
def discard(self, key):
if key in self.map:
key, prev, next = self.map.pop(key)
prev[2] = next
next[1] = prev
def __iter__(self):
end = self.end
curr = end[2]
while curr is not end:
yield curr[0]
curr = curr[2]
def __reversed__(self):
end = self.end
curr = end[1]
while curr is not end:
yield curr[0]
curr = curr[1]
def pop(self, last=True):
if not self:
raise KeyError('set is empty')
key = self.end[1][0] if last else self.end[2][0]
self.discard(key)
return key
def __repr__(self):
if not self:
return '%s()' % (self.__class__.__name__,)
return '%s(%r)' % (self.__class__.__name__, list(self))
def __eq__(self, other):
if isinstance(other, OrderedSet):
return len(self) == len(other) and list(self) == list(other)
return set(self) == set(other)
################################################################
#
# OrderedDefaultDict
#
################################################################
class OrderedDefaultDict(collections.OrderedDict):
"""
A Dictionary that maintains insertion order where missing values
are provided by a factory function, i.e., a combination of
the semantics of collections.defaultdict and collections.OrderedDict.
"""
def __init__(self, default_factory=None, *a, **kw):
if (default_factory is not None and
not callable(default_factory)):
raise TypeError('first argument must be callable')
collections.OrderedDict.__init__(self, *a, **kw)
self.default_factory = default_factory
def __getitem__(self, key):
try:
return collections.OrderedDict.__getitem__(self, key)
except KeyError:
return self.__missing__(key)
def __missing__(self, key):
if self.default_factory is None:
raise KeyError(key)
self[key] = value = self.default_factory()
return value
def __reduce__(self):
if self.default_factory is None:
args = tuple()
else:
args = self.default_factory,
return type(self), args, None, None, self.items()
def copy(self):
return self.__copy__()
def __copy__(self):
return type(self)(self.default_factory, self)
def __deepcopy__(self, memo):
import copy
return type(self)(self.default_factory,
copy.deepcopy(self.items()))
def __repr__(self):
return 'OrderedDefaultDict(%s, %s)' % (self.default_factory,
collections.OrderedDict.__repr__(self))
def find(func, iterable):
"""
find the first item in iterable for which func returns something true'ish.
@returns None if no item in iterable fulfills the condition
"""
for i in iterable:
if func(i):
return i
return None
def count(func, iteratable):
"""
count how the number of items in iterable for which func returns something true'ish.
"""
c = 0
for i in iterable:
if func(i):
c +=1
return c