Source Code for Module ganeti.compat

  1  # 
  2  # 
  3   
  4  # Copyright (C) 2010 Google Inc. 
  5  # 
  6  # This program is free software; you can redistribute it and/or modify 
  7  # it under the terms of the GNU General Public License as published by 
  8  # the Free Software Foundation; either version 2 of the License, or 
  9  # (at your option) any later version. 
 10  # 
 11  # This program is distributed in the hope that it will be useful, but 
 12  # WITHOUT ANY WARRANTY; without even the implied warranty of 
 13  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
 14  # General Public License for more details. 
 15  # 
 16  # You should have received a copy of the GNU General Public License 
 17  # along with this program; if not, write to the Free Software 
 18  # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 
 19  # 02110-1301, USA. 
 20   
 21   
 22  """Module containing backported language/library functionality. 
 23   
 24  """ 
 25   
 26  import itertools 
 27   
 28  try: 
 29    # pylint: disable-msg=F0401 
 30    import functools 
 31  except ImportError: 
 32    functools = None 
 33   
 34  try: 
 35    # pylint: disable-msg=F0401 
 36    import roman 
 37  except ImportError: 
 38    roman = None 
 39   
 40   
 41  # compat.md5_hash and compat.sha1_hash can be called to generate and md5 and a 
 42  # sha1 hashing modules, under python 2.4, 2.5 and 2.6, even though some changes 
 43  # went on. compat.sha1 is python-version specific and is used for python 
 44  # modules (hmac, for example) which have changed their behavior as well from 
 45  # one version to the other. 
 46  try: 
 47    # pylint: disable-msg=F0401 
 48    # Yes, we're not using the imports in this module. 
 49    # pylint: disable-msg=W0611 
 50    from hashlib import md5 as md5_hash 
 51    from hashlib import sha1 as sha1_hash 
 52    # this additional version is needed for compatibility with the hmac module 
 53    sha1 = sha1_hash 
 54  except ImportError: 
 55    from md5 import new as md5_hash 
 56    import sha 
 57    sha1 = sha 
 58    sha1_hash = sha.new 
 59   
 60   
 61 -def _all(seq): 
 62    """Returns True if all elements in the iterable are True. 
 63   
 64    """ 
 65    for _ in itertools.ifilterfalse(bool, seq): 
 66      return False 
 67    return True 
 68   
 69 -def _any(seq): 
 70    """Returns True if any element of the iterable are True. 
 71   
 72    """ 
 73    for _ in itertools.ifilter(bool, seq): 
 74      return True 
 75    return False 
 76   
 77  try: 
 78    # pylint: disable-msg=E0601 
 79    # pylint: disable-msg=W0622 
 80    all = all 
 81  except NameError: 
 82    all = _all 
 83   
 84  try: 
 85    # pylint: disable-msg=E0601 
 86    # pylint: disable-msg=W0622 
 87    any = any 
 88  except NameError: 
 89    any = _any 
 90   
 91 -def partition(seq, pred=bool): # pylint: disable-msg=W0622 
 92    """Partition a list in two, based on the given predicate. 
 93   
 94    """ 
 95    return (list(itertools.ifilter(pred, seq)), 
 96            list(itertools.ifilterfalse(pred, seq))) 
 97   
 98   
 99  # Even though we're using Python's built-in "partial" function if available, 
100  # this one is always defined for testing. 
101 -def _partial(func, *args, **keywords): # pylint: disable-msg=W0622 
102    """Decorator with partial application of arguments and keywords. 
103   
104    This function was copied from Python's documentation. 
105   
106    """ 
107    def newfunc(*fargs, **fkeywords): 
108      newkeywords = keywords.copy() 
109      newkeywords.update(fkeywords) 
110      return func(*(args + fargs), **newkeywords) # pylint: disable-msg=W0142 
111   
112    newfunc.func = func 
113    newfunc.args = args 
114    newfunc.keywords = keywords 
115    return newfunc 
116   
117   
118  if functools is None: 
119    partial = _partial 
120  else: 
121    partial = functools.partial 
122   
123   
124 -def TryToRoman(val, convert=True): 
125    """Try to convert a value to roman numerals 
126   
127    If the roman module could be loaded convert the given value to a roman 
128    numeral. Gracefully fail back to leaving the value untouched. 
129   
130    @type val: integer 
131    @param val: value to convert 
132    @type convert: boolean 
133    @param convert: if False, don't try conversion at all 
134    @rtype: string or typeof(val) 
135    @return: roman numeral for val, or val if conversion didn't succeed 
136   
137    """ 
138    if roman is not None and convert: 
139      try: 
140        return roman.toRoman(val) 
141      except roman.RomanError: 
142        return val 
143    else: 
144      return val 
145