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