libs/openid/kvform.py

   1 __all__ = ['seqToKV', 'kvToSeq', 'dictToKV', 'kvToDict']
   2
   3 from openid import oidutil
   4
   5 import types
   6
   7 class KVFormError(ValueError):
   8     pass
   9
  10 def seqToKV(seq, strict=False):
  11     """Represent a sequence of pairs of strings as newline-terminated
  12     key:value pairs. The pairs are generated in the order given.
  13
  14     @param seq: The pairs
  15     @type seq: [(str, (unicode|str))]
  16
  17     @return: A string representation of the sequence
  18     @rtype: str
  19     """
  20     def err(msg):
  21         formatted = 'seqToKV warning: %s: %r' % (msg, seq)
  22         if strict:
  23             raise KVFormError(formatted)
  24         else:
  25             oidutil.log(formatted)
  26
  27     lines = []
  28     for k, v in seq:
  29         if isinstance(k, types.StringType):
  30             k = k.decode('UTF8')
  31         elif not isinstance(k, types.UnicodeType):
  32             err('Converting key to string: %r' % k)
  33             k = str(k)
  34
  35         if '\n' in k:
  36             raise KVFormError(
  37                 'Invalid input for seqToKV: key contains newline: %r' % (k,))
  38
  39         if ':' in k:
  40             raise KVFormError(
  41                 'Invalid input for seqToKV: key contains colon: %r' % (k,))
  42
  43         if k.strip() != k:
  44             err('Key has whitespace at beginning or end: %r' % (k,))
  45
  46         if isinstance(v, types.StringType):
  47             v = v.decode('UTF8')
  48         elif not isinstance(v, types.UnicodeType):
  49             err('Converting value to string: %r' % (v,))
  50             v = str(v)
  51
  52         if '\n' in v:
  53             raise KVFormError(
  54                 'Invalid input for seqToKV: value contains newline: %r' % (v,))
  55
  56         if v.strip() != v:
  57             err('Value has whitespace at beginning or end: %r' % (v,))
  58
  59         lines.append(k + ':' + v + '\n')
  60
  61     return ''.join(lines).encode('UTF8')
  62
  63 def kvToSeq(data, strict=False):
  64     """
  65
  66     After one parse, seqToKV and kvToSeq are inverses, with no warnings::
  67
  68         seq = kvToSeq(s)
  69         seqToKV(kvToSeq(seq)) == seq
  70     """
  71     def err(msg):
  72         formatted = 'kvToSeq warning: %s: %r' % (msg, data)
  73         if strict:
  74             raise KVFormError(formatted)
  75         else:
  76             oidutil.log(formatted)
  77
  78     lines = data.split('\n')
  79     if lines[-1]:
  80         err('Does not end in a newline')
  81     else:
  82         del lines[-1]
  83
  84     pairs = []
  85     line_num = 0
  86     for line in lines:
  87         line_num += 1
  88
  89         # Ignore blank lines
  90         if not line.strip():
  91             continue
  92
  93         pair = line.split(':', 1)
  94         if len(pair) == 2:
  95             k, v = pair
  96             k_s = k.strip()
  97             if k_s != k:
  98                 fmt = ('In line %d, ignoring leading or trailing '
  99                        'whitespace in key %r')
 100                 err(fmt % (line_num, k))
 101
 102             if not k_s:
 103                 err('In line %d, got empty key' % (line_num,))
 104
 105             v_s = v.strip()
 106             if v_s != v:
 107                 fmt = ('In line %d, ignoring leading or trailing '
 108                        'whitespace in value %r')
 109                 err(fmt % (line_num, v))
 110
 111             pairs.append((k_s.decode('UTF8'), v_s.decode('UTF8')))
 112         else:
 113             err('Line %d does not contain a colon' % line_num)
 114
 115     return pairs
 116
 117 def dictToKV(d):
 118     seq = d.items()
 119     seq.sort()
 120     return seqToKV(seq)
 121
 122 def kvToDict(s):
 123     return dict(kvToSeq(s))