pyassuan/client.py

   1 # Copyright
   2
   3 import logging as _logging
   4 import sys as _sys
   5
   6 from . import LOG as _LOG
   7 from . import common as _common
   8 from . import error as _error
   9
  10
  11 class AssuanClient (object):
  12     """A single-threaded Assuan client based on the `devolpment suggestions`_
  13
  14     .. _development suggestions:
  15       http://www.gnupg.org/documentation/manuals/assuan/Client-code.html
  16     """
  17     def __init__(self, name, logger=_LOG, use_sublogger=True,
  18                  close_on_disconnect=False):
  19         self.name = name
  20         if use_sublogger:
  21             logger = _logging.getLogger('{}.{}'.format(logger.name, self.name))
  22         self.logger = logger
  23         self.close_on_disconnect = close_on_disconnect
  24         self.input = self.output = None
  25
  26     def connect(self):
  27         if not self.input:
  28             self.logger.info('read from stdin')
  29             self.input = _sys.stdin
  30         if not self.output:
  31             self.logger.info('write to stdout')
  32             self.output = _sys.stdout
  33
  34     def disconnect(self):
  35         if self.close_on_disconnect:
  36             self.logger.info('disconnecting')
  37             self.input = None
  38             self.output = None
  39
  40     def raise_error(self, error):
  41         self.logger.error(str(error))
  42         raise(error)
  43
  44     def read_response(self):
  45         line = self.input.readline()
  46         if not line:
  47             self.raise_error(
  48                 _error.AssuanError(message='IPC accept call failed'))
  49         if not line.endswith('\n'):
  50             self.raise_error(
  51                 _error.AssuanError(message='Invalid response'))
  52         line = line[:-1]  # remove trailing newline
  53         # TODO, line length?
  54         response = _common.Response()
  55         try:
  56             response.from_string(line)
  57         except _error.AssuanError as e:
  58             self.logger.error(str(e))
  59             raise
  60         self.logger.info('S: {}'.format(response))
  61         return response
  62
  63     def make_request(self, request):
  64         rstring = str(request)
  65         self.logger.info('C: {}'.format(rstring))
  66         self.output.write(rstring)
  67         self.output.write('\n')
  68         try:
  69             self.output.flush()
  70         except IOError:
  71             if not self.stop:
  72                 raise
  73         responses = list(self.responses())
  74         if responses[-1].type == 'ERR':
  75             eresponse = responses[-1]
  76             fields = eresponse.parameters.split(' ', 1)
  77             code = int(fields[0])
  78             if len(fields) > 1:
  79                 message = fields[1].strip()
  80             else:
  81                 message = None
  82             error = _error.AssuanError(code=code, message=message)
  83             error.request = request
  84             error.responses = responses
  85             raise error
  86         return responses
  87
  88     def responses(self):
  89         while True:
  90             response = self.read_response()
  91             yield response
  92             if response.type in ['OK', 'ERR']:
  93                 break