# -*- coding: Windows-1251 -*- ''' ''' import logging import os log=logging.getLogger('LogExtractor') BUF_SIZE=8*1024 class LogExtractor(object): ''' Save current position of first disk file-based handler and save log fragment up to current position into separated file by request. Useful for splitting common program log for further reviewing by unprofessional personnel/client ;) ''' def _find_file_handler(self, logger): # partially imported from Logger.callHandlers() c = logger filehandler=None while c: for hdlr in c.handlers: #log.info('Handler: %s' % type(hdlr)) if isinstance(hdlr, logging.FileHandler): filehandler=hdlr break if filehandler: break if not c.propagate: c = None #break out else: c = c.parent return filehandler def __init__(self, logger): ''' search for first FileHandler and store it's current position ''' self.init_ok=0 if not isinstance(logger, logging.Logger): log.error('__init__: must be instance of logging.Logger') return filehandler=self._find_file_handler(logger) if filehandler is None: log.error('__init__: no FileHandlers binded to ') return self.stream=filehandler.stream self.basename=filehandler.baseFilename self.start_pos=self.stream.tell() self.init_ok=1 def write_part(self, part_filename): ''' put log file fragment from saved position to cyurrent state into separate file ''' if not self.init_ok: log.error('not properly initialized') return 0 if self.stream.closed: if os.path.isfile(self.basename): part_size=os.path.getsize() else: log.error('log file (%s) not found on disk' % (self.basename)) return 0 else: part_size=self.stream.tell() - self.start_pos # put fragment f_log=open(self.basename, 'rb') f_part=open(part_filename, 'wb') try: f_log.seek(self.start_pos) left_size=part_size while left_size > 0: s=min(left_size, BUF_SIZE) buf=f_log.read(s) if len(buf) > 0: f_part.write(buf) left_size-=s else: break return 1 finally: f_part.close() f_log.close() return 0 if __name__ == '__main__': import sys logging.basicConfig(level=logging.DEBUG, format='%(asctime)s %(levelname)s %(message)s', filename='%s.log' % sys.argv[0], filemode='w') log=logging.getLogger('main') for i in range(1, 6): logextr=LogExtractor(log) # save current position for r in range(10): log.info('Pass %d: log message %d' % (i, r)) rc=logextr.write_part('pass_%d.log' % i) # put fragment to file log.info('write_part result: %r' % rc)