third_party/pycoverage/coverage/debug.py

   1 """Control of and utilities for debugging."""
   2
   3 import os
   4
   5
   6 # When debugging, it can be helpful to force some options, especially when
   7 # debugging the configuration mechanisms you usually use to control debugging!
   8 # This is a list of forced debugging options.
   9 FORCED_DEBUG = []
  10
  11
  12 class DebugControl(object):
  13     """Control and output for debugging."""
  14
  15     def __init__(self, options, output):
  16         """Configure the options and output file for debugging."""
  17         self.options = options
  18         self.output = output
  19
  20     def should(self, option):
  21         """Decide whether to output debug information in category `option`."""
  22         return (option in self.options or option in FORCED_DEBUG)
  23
  24     def write(self, msg):
  25         """Write a line of debug output."""
  26         if self.should('pid'):
  27             msg = "pid %5d: %s" % (os.getpid(), msg)
  28         self.output.write(msg+"\n")
  29         self.output.flush()
  30
  31     def write_formatted_info(self, info):
  32         """Write a sequence of (label,data) pairs nicely."""
  33         for line in info_formatter(info):
  34             self.write(" %s" % line)
  35
  36
  37 def info_formatter(info):
  38     """Produce a sequence of formatted lines from info.
  39
  40     `info` is a sequence of pairs (label, data).  The produced lines are
  41     nicely formatted, ready to print.
  42
  43     """
  44     label_len = max([len(l) for l, _d in info])
  45     for label, data in info:
  46         if data == []:
  47             data = "-none-"
  48         if isinstance(data, (list, tuple)):
  49             prefix = "%*s:" % (label_len, label)
  50             for e in data:
  51                 yield "%*s %s" % (label_len+1, prefix, e)
  52                 prefix = ""
  53         else:
  54             yield "%*s: %s" % (label_len, label, data)