# Copyright 2011 OpenStack Foundation. # 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. # # Copyright (c) 2017 Wind River Systems, Inc. # # The right to copy, distribute, modify, or otherwise make use # of this software may be licensed only pursuant to the terms # of an applicable Wind River license agreement. # """ System-level utilities and helper functions. """ import math import re import sys import unicodedata import six from dcmanagerclient.openstack.common.gettextutils import _ UNIT_PREFIX_EXPONENT = { 'k': 1, 'K': 1, 'Ki': 1, 'M': 2, 'Mi': 2, 'G': 3, 'Gi': 3, 'T': 4, 'Ti': 4, } UNIT_SYSTEM_INFO = { 'IEC': (1024, re.compile(r'(^[-+]?\d*\.?\d+)([KMGT]i?)?(b|bit|B)$')), 'SI': (1000, re.compile(r'(^[-+]?\d*\.?\d+)([kMGT])?(b|bit|B)$')), } TRUE_STRINGS = ('1', 't', 'true', 'on', 'y', 'yes') FALSE_STRINGS = ('0', 'f', 'false', 'off', 'n', 'no') SLUGIFY_STRIP_RE = re.compile(r"[^\w\s-]") SLUGIFY_HYPHENATE_RE = re.compile(r"[-\s]+") def int_from_bool_as_string(subject): """Interpret a string as a boolean and return either 1 or 0. Any string value in: ('True', 'true', 'On', 'on', '1') is interpreted as a boolean True. Useful for JSON-decoded stuff and config file parsing """ return bool_from_string(subject) and 1 or 0 def bool_from_string(subject, strict=False, default=False): """Interpret a string as a boolean. A case-insensitive match is performed such that strings matching 't', 'true', 'on', 'y', 'yes', or '1' are considered True and, when `strict=False`, anything else returns the value specified by 'default'. Useful for JSON-decoded stuff and config file parsing. If `strict=True`, unrecognized values, including None, will raise a ValueError which is useful when parsing values passed in from an API call. Strings yielding False are 'f', 'false', 'off', 'n', 'no', or '0'. """ if not isinstance(subject, six.string_types): subject = six.text_type(subject) lowered = subject.strip().lower() if lowered in TRUE_STRINGS: return True elif lowered in FALSE_STRINGS: return False elif strict: acceptable = ', '.join( "'%s'" % s for s in sorted(TRUE_STRINGS + FALSE_STRINGS)) msg = _("Unrecognized value '%(val)s', acceptable values are:" " %(acceptable)s") % {'val': subject, 'acceptable': acceptable} raise ValueError(msg) else: return default def safe_decode(text, incoming=None, errors='strict'): """Decodes incoming text/bytes string using `incoming` if they're not already unicode. :param incoming: Text's current encoding :param errors: Errors handling policy. See here for valid values http://docs.python.org/2/library/codecs.html :returns: text or a unicode `incoming` encoded representation of it. :raises TypeError: If text is not an instance of str """ if not isinstance(text, (six.string_types, six.binary_type)): raise TypeError("%s can't be decoded" % type(text)) if isinstance(text, six.text_type): return text if not incoming: incoming = (sys.stdin.encoding or sys.getdefaultencoding()) try: return text.decode(incoming, errors) except UnicodeDecodeError: # Note(flaper87) If we get here, it means that # sys.stdin.encoding / sys.getdefaultencoding # didn't return a suitable encoding to decode # text. This happens mostly when global LANG # var is not set correctly and there's no # default encoding. In this case, most likely # python will use ASCII or ANSI encoders as # default encodings but they won't be capable # of decoding non-ASCII characters. # # Also, UTF-8 is being used since it's an ASCII # extension. return text.decode('utf-8', errors) def safe_encode(text, incoming=None, encoding='utf-8', errors='strict'): """Encodes incoming text/bytes string using `encoding`. If incoming is not specified, text is expected to be encoded with current python's default encoding. (`sys.getdefaultencoding`) :param incoming: Text's current encoding :param encoding: Expected encoding for text (Default UTF-8) :param errors: Errors handling policy. See here for valid values http://docs.python.org/2/library/codecs.html :returns: text or a bytestring `encoding` encoded representation of it. :raises TypeError: If text is not an instance of str """ if not isinstance(text, (six.string_types, six.binary_type)): raise TypeError("%s can't be encoded" % type(text)) if not incoming: incoming = (sys.stdin.encoding or sys.getdefaultencoding()) if isinstance(text, six.text_type): return text.encode(encoding, errors) elif text and encoding != incoming: # Decode text before encoding it with `encoding` text = safe_decode(text, incoming, errors) return text.encode(encoding, errors) else: return text def string_to_bytes(text, unit_system='IEC', return_int=False): """Converts a string into an float representation of bytes. The units supported for IEC :: Kb(it), Kib(it), Mb(it), Mib(it), Gb(it), Gib(it), Tb(it), Tib(it) KB, KiB, MB, MiB, GB, GiB, TB, TiB The units supported for SI :: kb(it), Mb(it), Gb(it), Tb(it) kB, MB, GB, TB Note that the SI unit system does not support capital letter 'K' :param text: String input for bytes size conversion. :param unit_system: Unit system for byte size conversion. :param return_int: If True, returns integer representation of text in bytes. (default: decimal) :returns: Numerical representation of text in bytes. :raises ValueError: If text has an invalid value. """ try: base, reg_ex = UNIT_SYSTEM_INFO[unit_system] except KeyError: msg = _('Invalid unit system: "%s"') % unit_system raise ValueError(msg) match = reg_ex.match(text) if match: magnitude = float(match.group(1)) unit_prefix = match.group(2) if match.group(3) in ['b', 'bit']: magnitude /= 8 else: msg = _('Invalid string format: %s') % text raise ValueError(msg) if not unit_prefix: res = magnitude else: res = magnitude * pow(base, UNIT_PREFIX_EXPONENT[unit_prefix]) if return_int: return int(math.ceil(res)) return res def to_slug(value, incoming=None, errors="strict"): """Normalize string. Convert to lowercase, remove non-word characters, and convert spaces to hyphens. Inspired by Django's `slugify` filter. :param value: Text to slugify :param incoming: Text's current encoding :param errors: Errors handling policy. See here for valid values http://docs.python.org/2/library/codecs.html :returns: slugified unicode representation of `value` :raises TypeError: If text is not an instance of str """ value = safe_decode(value, incoming, errors) # NOTE(aababilov): no need to use safe_(encode|decode) here: # encodings are always "ascii", error handling is always "ignore" # and types are always known (first: unicode; second: str) value = unicodedata.normalize("NFKD", value).encode( "ascii", "ignore").decode("ascii") value = SLUGIFY_STRIP_RE.sub("", value).strip().lower() return SLUGIFY_HYPHENATE_RE.sub("-", value)