sfa/util/sfalogging.py

   1 #!/usr/bin/python
   2
   3 import os, sys
   4 import traceback
   5 import logging, logging.handlers
   6
   7 CRITICAL=logging.CRITICAL
   8 ERROR=logging.ERROR
   9 WARNING=logging.WARNING
  10 INFO=logging.INFO
  11 DEBUG=logging.DEBUG
  12
  13 # a logger that can handle tracebacks
  14 class _SfaLogger:
  15     def __init__ (self,logfile=None,loggername=None,level=logging.INFO):
  16         # default is to locate loggername from the logfile if avail.
  17         if not logfile:
  18             loggername='console'
  19             handler=logging.StreamHandler()
  20             handler.setFormatter(logging.Formatter("%(levelname)s %(message)s"))
  21         else:
  22             if not loggername:
  23                 loggername=os.path.basename(logfile)
  24             try:
  25                 handler=logging.handlers.RotatingFileHandler(logfile,maxBytes=1000000, backupCount=5)
  26             except IOError:
  27                 # This is usually a permissions error becaue the file is
  28                 # owned by root, but httpd is trying to access it.
  29                 tmplogfile=os.getenv("TMPDIR", "/tmp") + os.path.sep + os.path.basename(logfile)
  30                 handler=logging.handlers.RotatingFileHandler(tmplogfile,maxBytes=1000000, backupCount=5)
  31             handler.setFormatter(logging.Formatter("%(asctime)s - %(levelname)s - %(message)s"))
  32
  33         self.logger=logging.getLogger(loggername)
  34         self.logger.setLevel(level)
  35         self.logger.addHandler(handler)
  36         self.loggername=loggername
  37
  38     def setLevel(self,level):
  39         self.logger.setLevel(level)
  40
  41     # shorthand to avoid having to import logging all over the place
  42     def setLevelDebug(self):
  43         self.logger.setLevel(logging.DEBUG)
  44
  45     # define a verbose option with s/t like
  46     # parser.add_option("-v", "--verbose", action="count", dest="verbose", default=0)
  47     # and pass the coresponding options.verbose to this method to adjust level
  48     def setLevelFromOptVerbose(self,verbose):
  49         if verbose==0:
  50             self.logger.setLevel(logging.WARNING)
  51         elif verbose==1:
  52             self.logger.setLevel(logging.INFO)
  53         elif verbose==2:
  54             self.logger.setLevel(logging.DEBUG)
  55
  56     ####################
  57     def wrap(fun):
  58         def wrapped(self,msg,*args,**kwds):
  59             native=getattr(self.logger,fun.__name__)
  60             return native(msg,*args,**kwds)
  61         #wrapped.__doc__=native.__doc__
  62         return wrapped
  63
  64     @wrap
  65     def critical(): pass
  66     @wrap
  67     def error(): pass
  68     @wrap
  69     def warning(): pass
  70     @wrap
  71     def info(): pass
  72     @wrap
  73     def debug(): pass
  74
  75     # logs an exception - use in an except statement
  76     def log_exc(self,message):
  77         self.error("%s BEG TRACEBACK"%message+"\n"+traceback.format_exc().strip("\n"))
  78         self.error("%s END TRACEBACK"%message)
  79
  80     def log_exc_critical(self,message):
  81         self.critical("%s BEG TRACEBACK"%message+"\n"+traceback.format_exc().strip("\n"))
  82         self.critical("%s END TRACEBACK"%message)
  83
  84     # for investigation purposes, can be placed anywhere
  85     def log_stack(self,message):
  86         to_log="".join(traceback.format_stack())
  87         self.debug("%s BEG STACK"%message+"\n"+to_log)
  88         self.debug("%s END STACK"%message)
  89
  90 ####################
  91 # import-related operations go in this file
  92 _import_logger=_SfaLogger(logfile='/var/log/sfa_import.log')
  93 # servers log into /var/log/sfa.log
  94 _server_logger=_SfaLogger(logfile='/var/log/sfa.log')
  95 # clients use the console
  96 _console_logger=_SfaLogger()
  97
  98 # default is to use the server-side logger
  99 _the_logger=_server_logger
 100
 101 # clients would change the default by issuing one of these call
 102 def sfa_logger_goes_to_console():
 103     current_module=sys.modules[globals()['__name__']]
 104     current_module._the_logger=_console_logger
 105
 106 # clients would change the default by issuing one of these call
 107 def sfa_logger_goes_to_import():
 108     current_module=sys.modules[globals()['__name__']]
 109     current_module._logger=_sfa_import_logger
 110
 111 # this is how to retrieve the 'right' logger
 112 def sfa_logger():
 113     return _the_logger
 114
 115 ########################################
 116 import time
 117
 118 def profile(logger):
 119     """
 120     Prints the runtime of the specified callable. Use as a decorator, e.g.,
 121
 122     @profile(logger)
 123     def foo(...):
 124         ...
 125     """
 126     def logger_profile(callable):
 127         def wrapper(*args, **kwds):
 128             start = time.time()
 129             result = callable(*args, **kwds)
 130             end = time.time()
 131             args = map(str, args)
 132             args += ["%s = %s" % (name, str(value)) for (name, value) in kwds.items()]
 133             # should probably use debug, but then debug is not always enabled
 134             logger.info("PROFILED %s (%s): %.02f s" % (callable.__name__, ", ".join(args), end - start))
 135             return result
 136         return wrapper
 137     return logger_profile
 138
 139
 140 if __name__ == '__main__':
 141     print 'testing sfalogging into logger.log'
 142     logger=_SfaLogger('logger.log')
 143     logger.critical("logger.critical")
 144     logger.error("logger.error")
 145     logger.warning("logger.warning")
 146     logger.info("logger.info")
 147     logger.debug("logger.debug")
 148     logger.setLevel(logging.DEBUG)
 149     logger.debug("logger.debug again")
 150
 151     sfa_logger_goes_to_console()
 152     my_logger=sfa_logger()
 153     my_logger.info("redirected to console")
 154
 155     @profile(my_logger)
 156     def sleep(seconds = 1):
 157         time.sleep(seconds)
 158
 159     my_logger.info('console.info')
 160     sleep(0.5)
 161     my_logger.setLevel(logging.DEBUG)
 162     sleep(0.25)
 163