tko/parsers/base.py

   1 import traceback
   2
   3 from autotest_lib.tko import status_lib, utils as tko_utils
   4
   5
   6 class parser(object):
   7     """
   8     Abstract parser base class. Provides a generic implementation of the
   9     standard parser interfaction functions. The derived classes must
  10     implement a state_iterator method for this class to be useful.
  11     """
  12     def start(self, job):
  13         """ Initialize the parser for processing the results of
  14         'job'."""
  15         # initialize all the basic parser parameters
  16         self.job = job
  17         self.finished = False
  18         self.line_buffer = status_lib.line_buffer()
  19         # create and prime the parser state machine
  20         self.state = self.state_iterator(self.line_buffer)
  21         self.state.next()
  22
  23
  24     def process_lines(self, lines):
  25         """ Feed 'lines' into the parser state machine, and return
  26         a list of all the new test results produced."""
  27         self.line_buffer.put_multiple(lines)
  28         try:
  29             return self.state.next()
  30         except StopIteration:
  31             msg = ("WARNING: parser was called to process status "
  32                    "lines after it was end()ed\n"
  33                    "Current traceback:\n" +
  34                    traceback.format_exc() +
  35                    "\nCurrent stack:\n" +
  36                    "".join(traceback.format_stack()))
  37             tko_utils.dprint(msg)
  38             return []
  39
  40
  41     def end(self, lines=[]):
  42         """ Feed 'lines' into the parser state machine, signal to the
  43         state machine that no more lines are forthcoming, and then
  44         return a list of all the new test results produced."""
  45         self.line_buffer.put_multiple(lines)
  46         # run the state machine to clear out the buffer
  47         self.finished = True
  48         try:
  49             return self.state.next()
  50         except StopIteration:
  51             msg = ("WARNING: parser was end()ed multiple times\n"
  52                    "Current traceback:\n" +
  53                    traceback.format_exc() +
  54                    "\nCurrent stack:\n" +
  55                    "".join(traceback.format_stack()))
  56             tko_utils.dprint(msg)
  57             return []
  58
  59
  60     @staticmethod
  61     def make_job(dir):
  62         """ Create a new instance of the job model used by the
  63         parser, given a results directory."""
  64         raise NotImplemented
  65
  66
  67     def state_iterator(self, buffer):
  68         """ A generator method that implements the actual parser
  69         state machine. """
  70         raise NotImplemented