# vim: tabstop=4 shiftwidth=4 softtabstop=4 # 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. """ System-level utilities and helper functions. """ import re import sys import unicodedata import six from seamicroclient.openstack.common.gettextutils import _ # noqa # Used for looking up extensions of text # to their 'multiplied' byte amount BYTE_MULTIPLIERS = { '': 1, 't': 1024 ** 4, 'g': 1024 ** 3, 'm': 1024 ** 2, 'k': 1024, } BYTE_REGEX = re.compile(r'(^-?\d+)(\D*)') 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): """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 is considered False. 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 = str(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 False def safe_decode(text, incoming=None, errors='strict'): """Decodes incoming str 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 isntance of str """ if not isinstance(text, six.string_types): 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 str/unicode 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 isntance of str """ if not isinstance(text, six.string_types): 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) return text def to_bytes(text, default=0): """Converts a string into an integer of bytes. Looks at the last characters of the text to determine what conversion is needed to turn the input text into a byte number. Supports "B, K(B), M(B), G(B), and T(B)". (case insensitive) :param text: String input for bytes size conversion. :param default: Default return value when text is blank. """ match = BYTE_REGEX.search(text) if match: magnitude = int(match.group(1)) mult_key_org = match.group(2) if not mult_key_org: return magnitude elif text: msg = _('Invalid string format: %s') % text raise TypeError(msg) else: return default mult_key = mult_key_org.lower().replace('b', '', 1) multiplier = BYTE_MULTIPLIERS.get(mult_key) if multiplier is None: msg = _('Unknown byte multiplier: %s') % mult_key_org raise TypeError(msg) return magnitude * multiplier 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)