code/safety.py

   1 #file: safety.py
   2 #Copyright (C) 2008 FunnyMan3595
   3 #This file is part of Endgame: Singularity.
   4
   5 #Endgame: Singularity is free software; you can redistribute it and/or modify
   6 #it under the terms of the GNU General Public License as published by
   7 #the Free Software Foundation; either version 2 of the License, or
   8 #(at your option) any later version.
   9
  10 #Endgame: Singularity is distributed in the hope that it will be useful,
  11 #but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 #MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 #GNU General Public License for more details.
  14
  15 #You should have received a copy of the GNU General Public License
  16 #along with Endgame: Singularity; if not, write to the Free Software
  17 #Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18
  19 #This file contains wrapper functions for making error-tolerant "safe" calls.
  20
  21 import logging
  22 import time
  23 import traceback
  24 import sys
  25
  26 import os
  27 import os.path
  28
  29 # We store error.log in .endgame on OSes with a HOME directory;
  30 # otherwise, we store it in the CWD.  As we're not importing any
  31 # parts of E:S here, we have to reimplement this logic.
  32 logpath = "error.log"
  33 if os.environ.has_key("HOME"):
  34     prefs_dir = os.path.expanduser("~/.endgame")
  35     if not os.path.isdir(prefs_dir):
  36         os.makedirs(prefs_dir)
  37     logpath = os.path.join(prefs_dir, "error.log")
  38
  39 logging.getLogger().addHandler(logging.FileHandler(logpath))
  40
  41 class Buffer(object):
  42     def __init__(self, prefix=""):
  43         self.data = prefix
  44     def write(self, unbuffered):
  45         self.data += unbuffered
  46
  47 def get_timestamp(when=None):
  48     if when == None:
  49         when = time.time()
  50     return time.ctime(when) + " " + time.tzname[time.daylight]
  51
  52 def log_error(error_message):
  53     logging.getLogger().error(error_message)
  54     sys.stderr.write(error_message + "\n")
  55
  56 def safe_call(func, args=(), kwargs={}, on_error=None):
  57     try:
  58         return func(*args, **kwargs)
  59     except Exception, e:
  60         if isinstance(e, SystemExit):
  61             raise
  62         buffer = Buffer("Exception in function %s at %s:\n"
  63                                    % (func.__name__, get_timestamp()))
  64         traceback.print_exc(file=buffer)
  65         log_error(buffer.data)
  66
  67 #        # ... --- ...
  68 #        import g
  69 #        g.play_sound("click")
  70 #        delays = (.15, .15, .8, .5, .5, .8, .15, .15)
  71 #        for delay in delays:
  72 #            time.sleep(delay)
  73 #            g.play_sound("click")
  74
  75         return on_error
  76
  77 # Catches any errors raised by a function, logs them, and returns the given
  78 # value.
  79 #
  80 # Apply to a function like so:
  81 # @safe(my_error_code)
  82 # def my_function(...)
  83 #
  84 # And then:
  85 # result = my_function(...)
  86 # if result == my_error_code:
  87 #     # An error was raised.
  88 def safe(on_error):
  89     return lambda func: _safe(func, on_error)
  90
  91 def _safe(func, on_error):
  92     return lambda *args, **kwargs: safe_call(func, args, kwargs, on_error)