# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# Copyright 2011 Justin Santa Barbara
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# 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
# License for the specific language governing permissions and limitations
# under the License.
"""Utilities and helper functions."""
import bisect
import calendar
import copy
import datetime
import decimal
import fnmatch
import hashlib
import re
import struct
import sys
from oslo_concurrency import processutils
from oslo_config import cfg
from oslo_utils import timeutils
from oslo_utils import units
import six
OPTS = [
cfg.StrOpt('rootwrap_config',
default="/etc/ceilometer/rootwrap.conf",
help='Path to the rootwrap configuration file to'
'use for running commands as root'),
]
CONF = cfg.CONF
CONF.register_opts(OPTS)
EPOCH_TIME = datetime.datetime(1970, 1, 1)
def _get_root_helper():
return 'sudo ceilometer-rootwrap %s' % CONF.rootwrap_config
def execute(*cmd, **kwargs):
"""Convenience wrapper around oslo's execute() method."""
if 'run_as_root' in kwargs and 'root_helper' not in kwargs:
kwargs['root_helper'] = _get_root_helper()
return processutils.execute(*cmd, **kwargs)
def decode_unicode(input):
"""Decode the unicode of the message, and encode it into utf-8."""
if isinstance(input, dict):
temp = {}
# If the input data is a dict, create an equivalent dict with a
# predictable insertion order to avoid inconsistencies in the
# message signature computation for equivalent payloads modulo
# ordering
for key, value in sorted(six.iteritems(input)):
temp[decode_unicode(key)] = decode_unicode(value)
return temp
elif isinstance(input, (tuple, list)):
# When doing a pair of JSON encode/decode operations to the tuple,
# the tuple would become list. So we have to generate the value as
# list here.
return [decode_unicode(element) for element in input]
elif six.PY2 and isinstance(input, six.text_type):
return input.encode('utf-8')
elif six.PY3 and isinstance(input, six.binary_type):
return input.decode('utf-8')
else:
return input
def recursive_keypairs(d, separator=':'):
"""Generator that produces sequence of keypairs for nested dictionaries."""
for name, value in sorted(six.iteritems(d)):
if isinstance(value, dict):
for subname, subvalue in recursive_keypairs(value, separator):
yield ('%s%s%s' % (name, separator, subname), subvalue)
elif isinstance(value, (tuple, list)):
yield name, decode_unicode(value)
else:
yield name, value
def restore_nesting(d, separator=':'):
"""Unwinds a flattened dict to restore nesting."""
d = copy.copy(d) if any([separator in k for k in d.keys()]) else d
for k, v in d.copy().items():
if separator in k:
top, rem = k.split(separator, 1)
nest = d[top] if isinstance(d.get(top), dict) else {}
nest[rem] = v
d[top] = restore_nesting(nest, separator)
del d[k]
return d
def dt_to_decimal(utc):
"""Datetime to Decimal.
Some databases don't store microseconds in datetime
so we always store as Decimal unixtime.
"""
if utc is None:
return None
decimal.getcontext().prec = 30
return (decimal.Decimal(str(calendar.timegm(utc.utctimetuple()))) +
(decimal.Decimal(str(utc.microsecond)) /
decimal.Decimal("1000000.0")))
def decimal_to_dt(dec):
"""Return a datetime from Decimal unixtime format."""
if dec is None:
return None
integer = int(dec)
micro = (dec - decimal.Decimal(integer)) * decimal.Decimal(units.M)
daittyme = datetime.datetime.utcfromtimestamp(integer)
return daittyme.replace(microsecond=int(round(micro)))
def sanitize_timestamp(timestamp):
"""Return a naive utc datetime object."""
if not timestamp:
return timestamp
if not isinstance(timestamp, datetime.datetime):
timestamp = timeutils.parse_isotime(timestamp)
return timeutils.normalize_time(timestamp)
def stringify_timestamps(data):
"""Stringify any datetimes in given dict."""
isa_timestamp = lambda v: isinstance(v, datetime.datetime)
return dict((k, v.isoformat() if isa_timestamp(v) else v)
for (k, v) in six.iteritems(data))
def dict_to_keyval(value, key_base=None):
"""Expand a given dict to its corresponding key-value pairs.
Generated keys are fully qualified, delimited using dot notation.
ie. key = 'key.child_key.grandchild_key[0]'
"""
val_iter, key_func = None, None
if isinstance(value, dict):
val_iter = six.iteritems(value)
key_func = lambda k: key_base + '.' + k if key_base else k
elif isinstance(value, (tuple, list)):
val_iter = enumerate(value)
key_func = lambda k: key_base + '[%d]' % k
if val_iter:
for k, v in val_iter:
key_gen = key_func(k)
if isinstance(v, dict) or isinstance(v, (tuple, list)):
for key_gen, v in dict_to_keyval(v, key_gen):
yield key_gen, v
else:
yield key_gen, v
def lowercase_keys(mapping):
"""Converts the values of the keys in mapping to lowercase."""
items = mapping.items()
for key, value in items:
del mapping[key]
mapping[key.lower()] = value
def lowercase_values(mapping):
"""Converts the values in the mapping dict to lowercase."""
items = mapping.items()
for key, value in items:
mapping[key] = value.lower()
def update_nested(original_dict, updates):
"""Updates the leaf nodes in a nest dict.
Updates occur without replacing entire sub-dicts.
"""
dict_to_update = copy.deepcopy(original_dict)
for key, value in six.iteritems(updates):
if isinstance(value, dict):
sub_dict = update_nested(dict_to_update.get(key, {}), value)
dict_to_update[key] = sub_dict
else:
dict_to_update[key] = updates[key]
return dict_to_update
def uniq(dupes, attrs):
"""Exclude elements of dupes with a duplicated set of attribute values."""
key = lambda d: '/'.join([getattr(d, a) or '' for a in attrs])
keys = []
deduped = []
for d in dupes:
if key(d) not in keys:
deduped.append(d)
keys.append(key(d))
return deduped
def hash_of_set(s):
return str(hash(frozenset(s)))
[docs]class HashRing(object):
def __init__(self, nodes, replicas=100):
self._ring = dict()
self._sorted_keys = []
for node in nodes:
for r in six.moves.range(replicas):
hashed_key = self._hash('%s-%s' % (node, r))
self._ring[hashed_key] = node
self._sorted_keys.append(hashed_key)
self._sorted_keys.sort()
@staticmethod
def _hash(key):
return struct.unpack_from('>I',
hashlib.md5(str(key).encode()).digest())[0]
def _get_position_on_ring(self, key):
hashed_key = self._hash(key)
position = bisect.bisect(self._sorted_keys, hashed_key)
return position if position < len(self._sorted_keys) else 0
[docs] def get_node(self, key):
if not self._ring:
return None
pos = self._get_position_on_ring(key)
return self._ring[self._sorted_keys[pos]]
def kill_listeners(listeners):
# NOTE(gordc): correct usage of oslo.messaging listener is to stop(),
# which stops new messages, and wait(), which processes remaining
# messages and closes connection
for listener in listeners:
listener.stop()
listener.wait()
if sys.version_info > (2, 7, 9):
match = fnmatch.fnmatch
else:
_MATCH_CACHE = {}
_MATCH_CACHE_MAX = 100
def match(string, pattern):
"""Thread safe fnmatch re-implementation.
Standard library fnmatch in Python versions <= 2.7.9 has thread safe
issue, this helper function is created for such case. see:
https://bugs.python.org/issue23191
"""
string = string.lower()
pattern = pattern.lower()
cached_pattern = _MATCH_CACHE.get(pattern)
if cached_pattern is None:
translated_pattern = fnmatch.translate(pattern)
cached_pattern = re.compile(translated_pattern)
if len(_MATCH_CACHE) >= _MATCH_CACHE_MAX:
_MATCH_CACHE.clear()
_MATCH_CACHE[pattern] = cached_pattern
return cached_pattern.match(string) is not None