74 lines
2.6 KiB
Python
74 lines
2.6 KiB
Python
# Copyright (c) 2017 DataCore Software Corp. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""Utilities and helper functions."""
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from oslo_utils import netutils
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import six
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def build_network_address(host, port):
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"""Combines the specified host name or IP address with the specified port.
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:param host: Host name or IP address in presentation (string) format
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:param port: Port number
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:return: The host name or IP address and port combination;
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IPv6 addresses are enclosed in the square brackets
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"""
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if netutils.is_valid_ipv6(host):
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return '[%s]:%s' % (host, port)
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else:
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return '%s:%s' % (host, port)
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def get_first(predicate, source):
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"""Searches for an item that matches the conditions.
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:param predicate: Defines the conditions of the item to search for
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:param source: Iterable collection of items
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:return: The first item that matches the conditions defined by the
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specified predicate, if found; otherwise StopIteration is raised
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"""
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return six.next(item for item in source if predicate(item))
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def get_first_or_default(predicate, source, default):
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"""Searches for an item that matches the conditions.
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:param predicate: Defines the conditions of the item to search for
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:param source: Iterable collection of items
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:param default: Value that is returned if the iterator is exhausted
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:return: The first item that matches the conditions defined by the
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specified predicate, if found; otherwise the default value
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"""
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try:
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return get_first(predicate, source)
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except StopIteration:
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return default
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def get_distinct_by(key, source):
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"""Finds distinct items for the key and returns the result in a list.
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:param key: Function computing a key value for each item
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:param source: Iterable collection of items
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:return: The list of distinct by the key value items
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"""
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seen_keys = set()
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return [item for item in source
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if key(item) not in seen_keys and not seen_keys.add(key(item))]
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