git.maemo.org Git - dbuscron/blob - dbuscron/parser.py

   1 # encoding: utf-8
   2 from __future__ import with_statement
   3 import re
   4 from dbuscron.bus import DbusBus
   5
   6 def unescape(value):
   7     if not value or r'\x' not in value:
   8         return value
   9
  10     r = re.compile(r'\\x([0-9A-Fa-f]{2})')
  11     return r.sub(lambda m: chr(int(m.group(1), 16)), value)
  12
  13 def product(*args):
  14     if args:
  15         head, tail = args[0], args[1:]
  16         for h in head:
  17             for t in product(*tail):
  18                 yield (h,) + t
  19
  20     else:
  21         yield ()
  22
  23 class CrontabParserError(SyntaxError):
  24     def __init__(self, message, lineno, expected=None):
  25         if expected:
  26             if isinstance(expected, (tuple, list)):
  27                 exp = ' (expected %s or %s)' % (', '.join(expected[:-1]), expected[-1])
  28         else:
  29             exp = ''
  30
  31         msg = '%s%s at line %d' % (message, exp, lineno)
  32
  33         SyntaxError.__init__(self, msg)
  34
  35 class CrontabParser(object):
  36     __fields_sep = re.compile(r'\s+')
  37     __envvar_sep = re.compile(r'\s*=\s*')
  38     __fields_chk = {
  39             'bus_'         : None,
  40             'type_'        : ('signal','method_call','method_return','error'),
  41             'sender_'      : None,
  42             'interface_'   : re.compile(r'^[a-zA-Z][a-zA-Z0-9_.]+$'),
  43             'path_'        : re.compile(r'^/[a-zA-Z0-9_/]+$'),
  44             'member_'      : re.compile(r'^[a-zA-Z][a-zA-Z0-9_]+$'),
  45             'destination_' : None,
  46             'args_'        : None,
  47             }
  48     __fields = [
  49             'bus_',
  50             'type_',
  51             'sender_',
  52             'interface_',
  53             'path_',
  54             'member_',
  55             'destination_',
  56             'args_',
  57             ]
  58
  59     def __init__(self, fname):
  60         self.__bus = DbusBus()
  61         self.__filename = fname
  62         self.__environ = dict()
  63
  64     @property
  65     def environ(self):
  66         return self.__environ
  67
  68     def __iter__(self):
  69         # bus type sender interface path member destination args command
  70         lineno = 0
  71         with open(self.__filename) as f:
  72             for line in f:
  73                 lineno += 1
  74                 line = line.strip()
  75
  76                 if not line or line.startswith('#'):
  77                     continue
  78
  79                 parts = self.__fields_sep.split(line, 8)
  80                 if len(parts) < 9:
  81                     parts = self.__envvar_sep.split(line, 1)
  82                     if len(parts) == 2:
  83                         self.__environ[parts[0]] = parts[1]
  84                         continue
  85
  86                     raise CrontabParserError('Unexpected number of records', lineno)
  87
  88                 rule = [('s','S'), self.__fields_chk['type_'], (None,), (None,), (None,), (None,), (None,), (None,)]
  89
  90                 for p in range(0, 8):
  91                     if parts[p] != '*':
  92                         rule[p] = parts[p].split(',')
  93
  94                 command = parts[8]
  95
  96                 for r in product(*rule):
  97                     r = list(r)
  98                     if r[0] == 'S':
  99                         r[0] = self.__bus.system
 100                     elif r[0] == 's':
 101                         r[0] = self.__bus.session
 102                     else:
 103                         raise CrontabParserError('Unexpected bus value', lineno, expected=('S', 's', '*'))
 104
 105                     if r[7]:
 106                         r[7] = map(unescape, r[7].split(';'))
 107
 108                     ruled = dict()
 109                     for i, f in enumerate(self.__fields):
 110                         if self.__fields_chk[f]:
 111                             if isinstance(self.__fields_chk[f], tuple):
 112                                 if r[i] not in self.__fields_chk[f]:
 113                                     raise CrontabParserError('Unexpected %s value' % (f.strip('_')), lineno,
 114                                             expected=self.__fields_chk[f])
 115                             else:
 116                                 if not self.__fields_chk[f].match(r[i]):
 117                                     raise CrontabParserError('Incorrect %s value' % (f.strip('_')), lineno)
 118                         ruled[f] = r[i]
 119
 120                     yield ruled, command
 121
 122 def OptionsParser(args=None, help=u'', **opts):
 123
 124     from optparse import OptionParser
 125     import dbuscron
 126     parser = OptionParser(usage=help, version="%prog "+dbuscron.__version__)
 127     for opt, desc in opts.iteritems():
 128         names = desc.pop('names')
 129         desc['dest'] = opt
 130         parser.add_option(*names, **desc)
 131
 132     return parser.parse_args(args)[0]
 133