text: # Copyright 2001-2004 by Vinay Sajip. All Rights Reserved.
  #
  # Permission to use, copy, modify, and distribute this software and its
  # documentation for any purpose and without fee is hereby granted,
  # provided that the above copyright notice appear in all copies and that
  # both that copyright notice and this permission notice appear in
  # supporting documentation, and that the name of Vinay Sajip
  # not be used in advertising or publicity pertaining to distribution
  # of the software without specific, written prior permission.
  # VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
  # ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
  # VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
  # ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
  # IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  
  """
  Additional handlers for the logging package for Python. The core package is
  based on PEP 282 and comments thereto in comp.lang.python, and influenced by
  Apache's log4j system.
  
  Should work under Python versions >= 1.5.2, except that source line
  information is not available unless 'sys._getframe()' is.
  
  Copyright (C) 2001-2004 Vinay Sajip. All Rights Reserved.
  
  To use, simply 'import logging' and log away!
  """
  
  import sys, logging, socket, types, os, string, cPickle, struct, time
  
  from SocketServer import ThreadingTCPServer, StreamRequestHandler
  
  #
  # Some constants...
  #
  
  DEFAULT_TCP_LOGGING_PORT    = 9020
  DEFAULT_UDP_LOGGING_PORT    = 9021
  DEFAULT_HTTP_LOGGING_PORT   = 9022
  DEFAULT_SOAP_LOGGING_PORT   = 9023
  SYSLOG_UDP_PORT             = 514
  
  
  class RotatingFileHandler(logging.FileHandler):
      def __init__(self, filename, mode="a", maxBytes=0, backupCount=0):
          """
          Open the specified file and use it as the stream for logging.
  
          By default, the file grows indefinitely. You can specify particular
          values of maxBytes and backupCount to allow the file to rollover at
          a predetermined size.
  
          Rollover occurs whenever the current log file is nearly maxBytes in
          length. If backupCount is >= 1, the system will successively create
          new files with the same pathname as the base file, but with extensions
          ".1", ".2" etc. appended to it. For example, with a backupCount of 5
          and a base file name of "app.log", you would get "app.log",
          "app.log.1", "app.log.2", ... through to "app.log.5". The file being
          written to is always "app.log" - when it gets filled up, it is closed
          and renamed to "app.log.1", and if files "app.log.1", "app.log.2" etc.
          exist, then they are renamed to "app.log.2", "app.log.3" etc.
          respectively.
  
          If maxBytes is zero, rollover never occurs.
          """
          logging.FileHandler.__init__(self, filename, mode)
          self.maxBytes = maxBytes
          self.backupCount = backupCount
          if maxBytes > 0:
              self.mode = "a"
  
      def doRollover(self):
          """
          Do a rollover, as described in __init__().
          """
  
          self.stream.close()
          if self.backupCount > 0:
              for i in range(self.backupCount - 1, 0, -1):
                  sfn = "%s.%d" % (self.baseFilename, i)
                  dfn = "%s.%d" % (self.baseFilename, i + 1)
                  if os.path.exists(sfn):
                      #print "%s -> %s" % (sfn, dfn)
                      if os.path.exists(dfn):
                          os.remove(dfn)
                      os.rename(sfn, dfn)
              dfn = self.baseFilename + ".1"
              if os.path.exists(dfn):
                  os.remove(dfn)
              os.rename(self.baseFilename, dfn)
              #print "%s -> %s" % (self.baseFilename, dfn)
          self.stream = open(self.baseFilename, "w")
  
      def emit(self, record):
          """
          Emit a record.
  
          Output the record to the file, catering for rollover as described
          in doRollover().
          """
          if self.maxBytes > 0:                   # are we rolling over?
              msg = "%s\n" % self.format(record)
              self.stream.seek(0, 2)  #due to non-posix-compliant Windows feature
              if self.stream.tell() + len(msg) >= self.maxBytes:
                  self.doRollover()
          logging.FileHandler.emit(self, record)
  
  
  class SocketHandler(logging.Handler):
      """
      A handler class which writes logging records, in pickle format, to
      a streaming socket. The socket is kept open across logging calls.
      If the peer resets it, an attempt is made to reconnect on the next call.
      The pickle which is sent is that of the LogRecord's attribute dictionary
      (__dict__), so that the receiver does not need to have the logging module
      installed in order to process the logging event.
  
      To unpickle the record at the receiving end into a LogRecord, use the
      makeLogRecord function.
      """
  
      def __init__(self, host, port):
          """
          Initializes the handler with a specific host address and port.
  
          The attribute 'closeOnError' is set to 1 - which means that if
          a socket error occurs, the socket is silently closed and then
          reopened on the next logging call.
          """
          logging.Handler.__init__(self)
          self.host = host
          self.port = port
          self.sock = None
          self.closeOnError = 0
          self.retryTime = None
          #
          # Exponential backoff parameters.
          #
          self.retryStart = 1.0
          self.retryMax = 30.0
          self.retryFactor = 2.0
  
      def makeSocket(self):
          """
          A factory method which allows subclasses to define the precise
          type of socket they want.
          """
          s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
          s.connect((self.host, self.port))
          return s
  
      def createSocket(self):
          """
          Try to create a socket, using an exponential backoff with
          a max retry time. Thanks to Robert Olson for the original patch
          (SF #815911) which has been slightly refactored.
          """
          now = time.time()
          # Either retryTime is None, in which case this
          # is the first time back after a disconnect, or
          # we've waited long enough.
          if self.retryTime is None:
            attempt = 1
          else:
            attempt = (now >= self.retryTime)
          if attempt:
              try:
                  self.sock = self.makeSocket()
                  self.retryTime = None # next time, no delay before trying
              except:
                  #Creation failed, so set the retry time and return.
                  if self.retryTime is None:
                      self.retryPeriod = self.retryStart
                  else:
                      self.retryPeriod = self.retryPeriod * self.retryFactor
                      if self.retryPeriod > self.retryMax:
                          self.retryPeriod = self.retryMax
                  self.retryTime = now + self.retryPeriod
  
      def send(self, s):
          """
          Send a pickled string to the socket.
  
          This function allows for partial sends which can happen when the
          network is busy.
          """
          if self.sock is None:
              self.createSocket()
          #self.sock can be None either because we haven't reached the retry
          #time yet, or because we have reached the retry time and retried,
          #but are still unable to connect.
          if self.sock:
              try:
                  if hasattr(self.sock, "sendall"):
                      self.sock.sendall(s)
                  else:
                      sentsofar = 0
                      left = len(s)
                      while left > 0:
                          sent = self.sock.send(s[sentsofar:])
                          sentsofar = sentsofar + sent
                          left = left - sent
              except socket.error:
                  self.sock.close()
                  self.sock = None  # so we can call createSocket next time
  
      def makePickle(self, record):
          """
          Pickles the record in binary format with a length prefix, and
          returns it ready for transmission across the socket.
          """
          ei = record.exc_info
          if ei:
            dummy = self.format(record) # just to get traceback text into record.exc_text
            record.exc_info = None  # to avoid Unpickleable error
          s = cPickle.dumps(record.__dict__, 1)
          if ei:
            record.exc_info = ei  # for next handler
          slen = struct.pack(">L", len(s))
          return slen + s
  
      def handleError(self, record):
          """
          Handle an error during logging.
  
          An error has occurred during logging. Most likely cause -
          connection lost. Close the socket so that we can retry on the
          next event.
          """
          if self.closeOnError and self.sock:
              self.sock.close()
              self.sock = None        #try to reconnect next time
          else:
              logging.Handler.handleError(self, record)
  
      def emit(self, record):
          """
          Emit a record.
  
          Pickles the record and writes it to the socket in binary format.
          If there is an error with the socket, silently drop the packet.
          If there was a problem with the socket, re-establishes the
          socket.
          """
          try:
              s = self.makePickle(record)
              self.send(s)
          except:
              self.handleError(record)
  
      def close(self):
          """
          Closes the socket.
          """
          if self.sock:
              self.sock.close()
              self.sock = None
          logging.Handler.close(self)
  
  class DatagramHandler(SocketHandler):
      """
      A handler class which writes logging records, in pickle format, to
      a datagram socket.  The pickle which is sent is that of the LogRecord's
      attribute dictionary (__dict__), so that the receiver does not need to
      have the logging module installed in order to process the logging event.
  
      To unpickle the record at the receiving end into a LogRecord, use the
      makeLogRecord function.
  
      """
      def __init__(self, host, port):
          """
          Initializes the handler with a specific host address and port.
          """
          SocketHandler.__init__(self, host, port)
          self.closeOnError = 0
  
      def makeSocket(self):
          """
          The factory method of SocketHandler is here overridden to create
          a UDP socket (SOCK_DGRAM).
          """
          s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
          return s
  
      def send(self, s):
          """
          Send a pickled string to a socket.
  
          This function no longer allows for partial sends which can happen
          when the network is busy - UDP does not guarantee delivery and
          can deliver packets out of sequence.
          """
          self.sock.sendto(s, (self.host, self.port))
  
  class SysLogHandler(logging.Handler):
      """
      A handler class which sends formatted logging records to a syslog
      server. Based on Sam Rushing's syslog module:
      http://www.nightmare.com/squirl/python-ext/misc/syslog.py
      Contributed by Nicolas Untz (after which minor refactoring changes
      have been made).
      """
  
      # from <linux/sys/syslog.h>:
      # ======================================================================
      # priorities/facilities are encoded into a single 32-bit quantity, where
      # the bottom 3 bits are the priority (0-7) and the top 28 bits are the
      # facility (0-big number). Both the priorities and the facilities map
      # roughly one-to-one to strings in the syslogd(8) source code.  This
      # mapping is included in this file.
      #
      # priorities (these are ordered)
  
      LOG_EMERG     = 0       #  system is unusable
      LOG_ALERT     = 1       #  action must be taken immediately
      LOG_CRIT      = 2       #  critical conditions
      LOG_ERR       = 3       #  error conditions
      LOG_WARNING   = 4       #  warning conditions
      LOG_NOTICE    = 5       #  normal but significant condition
      LOG_INFO      = 6       #  informational
      LOG_DEBUG     = 7       #  debug-level messages
  
      #  facility codes
      LOG_KERN      = 0       #  kernel messages
      LOG_USER      = 1       #  random user-level messages
      LOG_MAIL      = 2       #  mail system
      LOG_DAEMON    = 3       #  system daemons
      LOG_AUTH      = 4       #  security/authorization messages
      LOG_SYSLOG    = 5       #  messages generated internally by syslogd
      LOG_LPR       = 6       #  line printer subsystem
      LOG_NEWS      = 7       #  network news subsystem
      LOG_UUCP      = 8       #  UUCP subsystem
      LOG_CRON      = 9       #  clock daemon
      LOG_AUTHPRIV  = 10  #  security/authorization messages (private)
  
      #  other codes through 15 reserved for system use
      LOG_LOCAL0    = 16      #  reserved for local use
      LOG_LOCAL1    = 17      #  reserved for local use
      LOG_LOCAL2    = 18      #  reserved for local use
      LOG_LOCAL3    = 19      #  reserved for local use
      LOG_LOCAL4    = 20      #  reserved for local use
      LOG_LOCAL5    = 21      #  reserved for local use
      LOG_LOCAL6    = 22      #  reserved for local use
      LOG_LOCAL7    = 23      #  reserved for local use
  
      priority_names = {
          "alert":    LOG_ALERT,
          "crit":     LOG_CRIT,
          "critical": LOG_CRIT,
          "debug":    LOG_DEBUG,
          "emerg":    LOG_EMERG,
          "err":      LOG_ERR,
          "error":    LOG_ERR,        #  DEPRECATED
          "info":     LOG_INFO,
          "notice":   LOG_NOTICE,
          "panic":    LOG_EMERG,      #  DEPRECATED
          "warn":     LOG_WARNING,    #  DEPRECATED
          "warning":  LOG_WARNING,
          }
  
      facility_names = {
          "auth":     LOG_AUTH,
          "authpriv": LOG_AUTHPRIV,
          "cron":     LOG_CRON,
          "daemon":   LOG_DAEMON,
          "kern":     LOG_KERN,
          "lpr":      LOG_LPR,
          "mail":     LOG_MAIL,
          "news":     LOG_NEWS,
          "security": LOG_AUTH,       #  DEPRECATED
          "syslog":   LOG_SYSLOG,
          "user":     LOG_USER,
          "uucp":     LOG_UUCP,
          "local0":   LOG_LOCAL0,
          "local1":   LOG_LOCAL1,
          "local2":   LOG_LOCAL2,
          "local3":   LOG_LOCAL3,
          "local4":   LOG_LOCAL4,
          "local5":   LOG_LOCAL5,
          "local6":   LOG_LOCAL6,
          "local7":   LOG_LOCAL7,
          }
  
      def __init__(self, address=('localhost', SYSLOG_UDP_PORT), facility=LOG_USER):
          """
          Initialize a handler.
  
          If address is specified as a string, UNIX socket is used.
          If facility is not specified, LOG_USER is used.
          """
          logging.Handler.__init__(self)
  
          self.address = address
          self.facility = facility
          if type(address) == types.StringType:
              self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
              # syslog may require either DGRAM or STREAM sockets
              try:
                  self.socket.connect(address)
              except socket.error:
                  self.socket.close()
                  self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
              self.socket.connect(address)
              self.unixsocket = 1
          else:
              self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
              self.unixsocket = 0
  
          self.formatter = None
  
      # curious: when talking to the unix-domain '/dev/log' socket, a
      #   zero-terminator seems to be required.  this string is placed
      #   into a class variable so that it can be overridden if
      #   necessary.
      log_format_string = '<%d>%s\000'
  
      def encodePriority (self, facility, priority):
          """
          Encode the facility and priority. You can pass in strings or
          integers - if strings are passed, the facility_names and
          priority_names mapping dictionaries are used to convert them to
          integers.
          """
          if type(facility) == types.StringType:
              facility = self.facility_names[facility]
          if type(priority) == types.StringType:
              priority = self.priority_names[priority]
          return (facility << 3) | priority
  
      def close (self):
          """
          Closes the socket.
          """
          if self.unixsocket:
              self.socket.close()
          logging.Handler.close(self)
  
      def emit(self, record):
          """
          Emit a record.
  
          The record is formatted, and then sent to the syslog server. If
          exception information is present, it is NOT sent to the server.
          """
          msg = self.format(record)
          """
          We need to convert record level to lowercase, maybe this will
          change in the future.
          """
          msg = self.log_format_string % (
              self.encodePriority(self.facility,
                                  string.lower(record.levelname)),
              msg)
          try:
              if self.unixsocket:
                  self.socket.send(msg)
              else:
                  self.socket.sendto(msg, self.address)
          except:
              self.handleError(record)
  
  class SMTPHandler(logging.Handler):
      """
      A handler class which sends an SMTP email for each logging event.
      """
      def __init__(self, mailhost, fromaddr, toaddrs, subject):
          """
          Initialize the handler.
  
          Initialize the instance with the from and to addresses and subject
          line of the email. To specify a non-standard SMTP port, use the
          (host, port) tuple format for the mailhost argument.
          """
          logging.Handler.__init__(self)
          if type(mailhost) == types.TupleType:
              host, port = mailhost
              self.mailhost = host
              self.mailport = port
          else:
              self.mailhost = mailhost
              self.mailport = None
          self.fromaddr = fromaddr
          if type(toaddrs) == types.StringType:
              toaddrs = [toaddrs]
          self.toaddrs = toaddrs
          self.subject = subject
  
      def getSubject(self, record):
          """
          Determine the subject for the email.
  
          If you want to specify a subject line which is record-dependent,
          override this method.
          """
          return self.subject
  
      weekdayname = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
  
      monthname = [None,
                   'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
                   'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
  
      def date_time(self):
          """Return the current date and time formatted for a MIME header."""
          year, month, day, hh, mm, ss, wd, y, z = time.gmtime(time.time())
          s = "%s, %02d %3s %4d %02d:%02d:%02d GMT" % (
                  self.weekdayname[wd],
                  day, self.monthname[month], year,
                  hh, mm, ss)
          return s
  
      def emit(self, record):
          """
          Emit a record.
  
          Format the record and send it to the specified addressees.
          """
          try:
              import smtplib
              port = self.mailport
              if not port:
                  port = smtplib.SMTP_PORT
              smtp = smtplib.SMTP(self.mailhost, port)
              msg = self.format(record)
              msg = "From: %s\r\nTo: %s\r\nSubject: %s\r\nDate: %s\r\n\r\n%s" % (
                              self.fromaddr,
                              string.join(self.toaddrs, ","),
                              self.getSubject(record),
                              self.date_time(), msg)
              smtp.sendmail(self.fromaddr, self.toaddrs, msg)
              smtp.quit()
          except:
              self.handleError(record)
  
  class NTEventLogHandler(logging.Handler):
      """
      A handler class which sends events to the NT Event Log. Adds a
      registry entry for the specified application name. If no dllname is
      provided, win32service.pyd (which contains some basic message
      placeholders) is used. Note that use of these placeholders will make
      your event logs big, as the entire message source is held in the log.
      If you want slimmer logs, you have to pass in the name of your own DLL
      which contains the message definitions you want to use in the event log.
      """
      def __init__(self, appname, dllname=None, logtype="Application"):
          logging.Handler.__init__(self)
          try:
              import win32evtlogutil, win32evtlog
              self.appname = appname
              self._welu = win32evtlogutil
              if not dllname:
                  dllname = os.path.split(self._welu.__file__)
                  dllname = os.path.split(dllname[0])
                  dllname = os.path.join(dllname[0], r'win32service.pyd')
              self.dllname = dllname
              self.logtype = logtype
              self._welu.AddSourceToRegistry(appname, dllname, logtype)
              self.deftype = win32evtlog.EVENTLOG_ERROR_TYPE
              self.typemap = {
                  logging.DEBUG   : win32evtlog.EVENTLOG_INFORMATION_TYPE,
                  logging.INFO    : win32evtlog.EVENTLOG_INFORMATION_TYPE,
                  logging.WARNING : win32evtlog.EVENTLOG_WARNING_TYPE,
                  logging.ERROR   : win32evtlog.EVENTLOG_ERROR_TYPE,
                  logging.CRITICAL: win32evtlog.EVENTLOG_ERROR_TYPE,
           }
          except ImportError:
              print "The Python Win32 extensions for NT (service, event "\
                          "logging) appear not to be available."
              self._welu = None
  
      def getMessageID(self, record):
          """
          Return the message ID for the event record. If you are using your
          own messages, you could do this by having the msg passed to the
          logger being an ID rather than a formatting string. Then, in here,
          you could use a dictionary lookup to get the message ID. This
          version returns 1, which is the base message ID in win32service.pyd.
          """
          return 1
  
      def getEventCategory(self, record):
          """
          Return the event category for the record.
  
          Override this if you want to specify your own categories. This version
          returns 0.
          """
          return 0
  
      def getEventType(self, record):
          """
          Return the event type for the record.
  
          Override this if you want to specify your own types. This version does
          a mapping using the handler's typemap attribute, which is set up in
          __init__() to a dictionary which contains mappings for DEBUG, INFO,
          WARNING, ERROR and CRITICAL. If you are using your own levels you will
          either need to override this method or place a suitable dictionary in
          the handler's typemap attribute.
          """
          return self.typemap.get(record.levelno, self.deftype)
  
      def emit(self, record):
          """
          Emit a record.
  
          Determine the message ID, event category and event type. Then
          log the message in the NT event log.
          """
          if self._welu:
              try:
                  id = self.getMessageID(record)
                  cat = self.getEventCategory(record)
                  type = self.getEventType(record)
                  msg = self.format(record)
                  self._welu.ReportEvent(self.appname, id, cat, type, [msg])
              except:
                  self.handleError(record)
  
      def close(self):
          """
          Clean up this handler.
  
          You can remove the application name from the registry as a
          source of event log entries. However, if you do this, you will
          not be able to see the events as you intended in the Event Log
          Viewer - it needs to be able to access the registry to get the
          DLL name.
          """
          #self._welu.RemoveSourceFromRegistry(self.appname, self.logtype)
          logging.Handler.close(self)
  
  class HTTPHandler(logging.Handler):
      """
      A class which sends records to a Web server, using either GET or
      POST semantics.
      """
      def __init__(self, host, url, method="GET"):
          """
          Initialize the instance with the host, the request URL, and the method
          ("GET" or "POST")
          """
          logging.Handler.__init__(self)
          method = string.upper(method)
          if method not in ["GET", "POST"]:
              raise ValueError, "method must be GET or POST"
          self.host = host
          self.url = url
          self.method = method
  
      def mapLogRecord(self, record):
          """
          Default implementation of mapping the log record into a dict
          that is sent as the CGI data. Overwrite in your class.
          Contributed by Franz  Glasner.
          """
          return record.__dict__
  
      def emit(self, record):
          """
          Emit a record.
  
          Send the record to the Web server as an URL-encoded dictionary
          """
          try:
              import httplib, urllib
              h = httplib.HTTP(self.host)
              url = self.url
              data = urllib.urlencode(self.mapLogRecord(record))
              if self.method == "GET":
                  if (string.find(url, '?') >= 0):
                      sep = '&'
                  else:
                      sep = '?'
                  url = url + "%c%s" % (sep, data)
              h.putrequest(self.method, url)
              if self.method == "POST":
                  h.putheader("Content-length", str(len(data)))
              h.endheaders()
              if self.method == "POST":
                  h.send(data)
              h.getreply()    #can't do anything with the result
          except:
              self.handleError(record)
  
  class BufferingHandler(logging.Handler):
      """
    A handler class which buffers logging records in memory. Whenever each
    record is added to the buffer, a check is made to see if the buffer should
    be flushed. If it should, then flush() is expected to do what's needed.
      """
      def __init__(self, capacity):
          """
          Initialize the handler with the buffer size.
          """
          logging.Handler.__init__(self)
          self.capacity = capacity
          self.buffer = []
  
      def shouldFlush(self, record):
          """
          Should the handler flush its buffer?
  
          Returns true if the buffer is up to capacity. This method can be
          overridden to implement custom flushing strategies.
          """
          return (len(self.buffer) >= self.capacity)
  
      def emit(self, record):
          """
          Emit a record.
  
          Append the record. If shouldFlush() tells us to, call flush() to process
          the buffer.
          """
          self.buffer.append(record)
          if self.shouldFlush(record):
              self.flush()
  
      def flush(self):
          """
          Override to implement custom flushing behaviour.
  
          This version just zaps the buffer to empty.
          """
          self.buffer = []
  
      def close(self):
          """
          Close the handler.
  
          This version just flushes and chains to the parent class' close().
          """
          self.flush()
          logging.Handler.close(self)
  
  class MemoryHandler(BufferingHandler):
      """
      A handler class which buffers logging records in memory, periodically
      flushing them to a target handler. Flushing occurs whenever the buffer
      is full, or when an event of a certain severity or greater is seen.
      """
      def __init__(self, capacity, flushLevel=logging.ERROR, target=None):
          """
          Initialize the handler with the buffer size, the level at which
          flushing should occur and an optional target.
  
          Note that without a target being set either here or via setTarget(),
          a MemoryHandler is no use to anyone!
          """
          BufferingHandler.__init__(self, capacity)
          self.flushLevel = flushLevel
          self.target = target
  
      def shouldFlush(self, record):
          """
          Check for buffer full or a record at the flushLevel or higher.
          """
          return (len(self.buffer) >= self.capacity) or \
                  (record.levelno >= self.flushLevel)
  
      def setTarget(self, target):
          """
          Set the target handler for this handler.
          """
          self.target = target
  
      def flush(self):
          """
          For a MemoryHandler, flushing means just sending the buffered
          records to the target, if there is one. Override if you want
          different behaviour.
          """
          if self.target:
              for record in self.buffer:
                  self.target.handle(record)
              self.buffer = []
  
      def close(self):
          """
          Flush, set the target to None and lose the buffer.
          """
          self.flush()
          self.target = None
          BufferingHandler.close(self)
  