docker-offlineimap/offlineimap/ui/UIBase.py
John Goerzen e1fb9492f8 Patch for signal handling to start a sync by Jim Pryor
Here's the way I'd like to use offlineimap on my laptop:
    1. Have a regular cron job running infrequently. The cron job
    checks to see
if I'm online, plugged in, and that no other copy of offlineimap is
running. If
all of these conditions are satisfied, it runs offlineimap just once:
"offlineimap -o -u Noninteractive.Quiet"

    2. When I start up mutt, I do it by calling a wrapper script that
    delays
until cron-started copies of offlineimap have finished, then starts
    offlineimap
on its regular, stay-alive and keep checking schedule. When I quit
    mutt, the
wrapper script tells offlineimap to stop.

This way I get frequent regular checks while I have mutt running, but
I don't
waste my battery/cpu checking frequently for mail when I'm not
interested in
it.

To make this work, though, it'd be nicer if it were easier to tell
offlineimap,
from the outside, things like "terminate cleanly now" and "when you've
finished
synching, then terminate instead of sleeping and synching again."

OK, to put my money where my mouth is, I attach two patches against
offlineimap
6.0.3.

The first, "cleanup.patch", cleans up a few spots that tend to throw
exceptions
for me as offlineimap is exiting from a KeyboardInterrupt.

The second adds signaling capabilities to offlineimap.

* sending a SIGTERM tells offlineimap to terminate immediately but
  cleanly,
  just as if "q" had been pressed in the GUI interface

* sending a SIGUSR1 tells every account to do a full sync asap: if
  it's
  sleeping, then wake up and do the sync now. If it's mid-sync, then
  re-synch
  any folders whose syncing has already been started or completed, and
  continue
  to synch the other, queued but not-yet-synched folders.

* sending a SIGHUP tells every account to die as soon as it can (but
  not
  immediately: only after finishing any synch it's now engaged in)

* sending a SIGUSR2 tells every account to do a full sync asap (as
  with
  SIGUSR1), then die

It's tricky to mix signals with threads, but I think I've done this
correctly.
I've been using it now for a few weeks without any obvious
problems. But I'm passing it
on so that others can review the code and test it out on their
systems. I developed the
patch when I was running Python 2.5.2, but to my knowledge I don't use
any Python 2.5-specific
code. Now I'm using the patch with Python 2.6.

Although I said "without any obvious problems," let me confess that
I'm
seeing offlineimap regularly choke when I do things like this: start
up
my offlineimap-wrapped copy of mutt, wait a while, put the machine to
sleep (not sure if offlineimap is active in the background or idling),
move to a different spot, wake the machine up again and it acquires a
new network, sometimes a wired network instead of wifi. Offlineimap
doesn't like that so much. I don't yet have any reason to think the
problems here come from my patches. But I'm just acknowledging them,
so
that if others are able to use offlineimap without any difficulty in
situations like I described, then maybe the fault is with my patches.
2008-12-01 16:13:16 -06:00

364 lines
14 KiB
Python

# UI base class
# Copyright (C) 2002 John Goerzen
# <jgoerzen@complete.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
import offlineimap.version
import re, time, sys, traceback, threading, thread
from StringIO import StringIO
from Queue import Empty
debugtypes = {'imap': 'IMAP protocol debugging',
'maildir': 'Maildir repository debugging',
'thread': 'Threading debugging'}
globalui = None
def setglobalui(newui):
global globalui
globalui = newui
def getglobalui():
global globalui
return globalui
class UIBase:
def __init__(s, config, verbose = 0):
s.verbose = verbose
s.config = config
s.debuglist = []
s.debugmessages = {}
s.debugmsglen = 50
s.threadaccounts = {}
s.logfile = None
################################################## UTILS
def _msg(s, msg):
"""Generic tool called when no other works."""
s._log(msg)
s._display(msg)
def _log(s, msg):
"""Log it to disk. Returns true if it wrote something; false
otherwise."""
if s.logfile:
s.logfile.write("%s: %s\n" % (threading.currentThread().getName(),
msg))
return 1
return 0
def setlogfd(s, logfd):
s.logfile = logfd
logfd.write("This is %s %s\n" % \
(offlineimap.version.productname,
offlineimap.version.versionstr))
logfd.write("Python: %s\n" % sys.version)
logfd.write("Platform: %s\n" % sys.platform)
logfd.write("Args: %s\n" % sys.argv)
def _display(s, msg):
"""Display a message."""
raise NotImplementedError
def warn(s, msg, minor = 0):
if minor:
s._msg("warning: " + msg)
else:
s._msg("WARNING: " + msg)
def registerthread(s, account):
"""Provides a hint to UIs about which account this particular
thread is processing."""
if s.threadaccounts.has_key(threading.currentThread()):
raise ValueError, "Thread %s already registered (old %s, new %s)" %\
(threading.currentThread().getName(),
s.getthreadaccount(s), account)
s.threadaccounts[threading.currentThread()] = account
def unregisterthread(s, thr):
"""Recognizes a thread has exited."""
if s.threadaccounts.has_key(thr):
del s.threadaccounts[thr]
def getthreadaccount(s, thr = None):
if not thr:
thr = threading.currentThread()
if s.threadaccounts.has_key(thr):
return s.threadaccounts[thr]
return '*Control'
def debug(s, debugtype, msg):
thisthread = threading.currentThread()
if s.debugmessages.has_key(thisthread):
s.debugmessages[thisthread].append("%s: %s" % (debugtype, msg))
else:
s.debugmessages[thisthread] = ["%s: %s" % (debugtype, msg)]
while len(s.debugmessages[thisthread]) > s.debugmsglen:
s.debugmessages[thisthread] = s.debugmessages[thisthread][1:]
if debugtype in s.debuglist:
if not s._log("DEBUG[%s]: %s" % (debugtype, msg)):
s._display("DEBUG[%s]: %s" % (debugtype, msg))
def add_debug(s, debugtype):
global debugtypes
if debugtype in debugtypes:
if not debugtype in s.debuglist:
s.debuglist.append(debugtype)
s.debugging(debugtype)
else:
s.invaliddebug(debugtype)
def debugging(s, debugtype):
global debugtypes
s._msg("Now debugging for %s: %s" % (debugtype, debugtypes[debugtype]))
def invaliddebug(s, debugtype):
s.warn("Invalid debug type: %s" % debugtype)
def locked(s):
raise Exception, "Another OfflineIMAP is running with the same metadatadir; exiting."
def getnicename(s, object):
prelimname = str(object.__class__).split('.')[-1]
# Strip off extra stuff.
return re.sub('(Folder|Repository)', '', prelimname)
def isusable(s):
"""Returns true if this UI object is usable in the current
environment. For instance, an X GUI would return true if it's
being run in X with a valid DISPLAY setting, and false otherwise."""
return 1
################################################## INPUT
def getpass(s, accountname, config, errmsg = None):
raise NotImplementedError
def folderlist(s, list):
return ', '.join(["%s[%s]" % (s.getnicename(x), x.getname()) for x in list])
################################################## WARNINGS
def msgtoreadonly(s, destfolder, uid, content, flags):
if not (s.config.has_option('general', 'ignore-readonly') and s.config.getboolean("general", "ignore-readonly")):
s.warn("Attempted to synchronize message %d to folder %s[%s], but that folder is read-only. The message will not be copied to that folder." % \
(uid, s.getnicename(destfolder), destfolder.getname()))
def flagstoreadonly(s, destfolder, uidlist, flags):
if not (s.config.has_option('general', 'ignore-readonly') and s.config.getboolean("general", "ignore-readonly")):
s.warn("Attempted to modify flags for messages %s in folder %s[%s], but that folder is read-only. No flags have been modified for that message." % \
(str(uidlist), s.getnicename(destfolder), destfolder.getname()))
def deletereadonly(s, destfolder, uidlist):
if not (s.config.has_option('general', 'ignore-readonly') and s.config.getboolean("general", "ignore-readonly")):
s.warn("Attempted to delete messages %s in folder %s[%s], but that folder is read-only. No messages have been deleted in that folder." % \
(str(uidlist), s.getnicename(destfolder), destfolder.getname()))
################################################## MESSAGES
def init_banner(s):
"""Called when the UI starts. Must be called before any other UI
call except isusable(). Displays the copyright banner. This is
where the UI should do its setup -- TK, for instance, would
create the application window here."""
if s.verbose >= 0:
s._msg(offlineimap.version.banner)
def connecting(s, hostname, port):
if s.verbose < 0:
return
if hostname == None:
hostname = ''
if port != None:
port = ":%s" % str(port)
displaystr = ' to %s%s.' % (hostname, port)
if hostname == '' and port == None:
displaystr = '.'
s._msg("Establishing connection" + displaystr)
def acct(s, accountname):
if s.verbose >= 0:
s._msg("***** Processing account %s" % accountname)
def acctdone(s, accountname):
if s.verbose >= 0:
s._msg("***** Finished processing account " + accountname)
def syncfolders(s, srcrepos, destrepos):
if s.verbose >= 0:
s._msg("Copying folder structure from %s to %s" % \
(s.getnicename(srcrepos), s.getnicename(destrepos)))
############################## Folder syncing
def syncingfolder(s, srcrepos, srcfolder, destrepos, destfolder):
"""Called when a folder sync operation is started."""
if s.verbose >= 0:
s._msg("Syncing %s: %s -> %s" % (srcfolder.getname(),
s.getnicename(srcrepos),
s.getnicename(destrepos)))
def skippingfolder(s, folder):
"""Called when a folder sync operation is started."""
if s.verbose >= 0:
s._msg("Skipping %s (not changed)" % folder.getname())
def validityproblem(s, folder):
s.warn("UID validity problem for folder %s (repo %s) (saved %d; got %d); skipping it" % \
(folder.getname(), folder.getrepository().getname(),
folder.getsaveduidvalidity(), folder.getuidvalidity()))
def loadmessagelist(s, repos, folder):
if s.verbose > 0:
s._msg("Loading message list for %s[%s]" % (s.getnicename(repos),
folder.getname()))
def messagelistloaded(s, repos, folder, count):
if s.verbose > 0:
s._msg("Message list for %s[%s] loaded: %d messages" % \
(s.getnicename(repos), folder.getname(), count))
############################## Message syncing
def syncingmessages(s, sr, sf, dr, df):
if s.verbose > 0:
s._msg("Syncing messages %s[%s] -> %s[%s]" % (s.getnicename(sr),
sf.getname(),
s.getnicename(dr),
df.getname()))
def copyingmessage(s, uid, src, destlist):
if s.verbose >= 0:
ds = s.folderlist(destlist)
s._msg("Copy message %d %s[%s] -> %s" % (uid, s.getnicename(src),
src.getname(), ds))
def deletingmessage(s, uid, destlist):
if s.verbose >= 0:
ds = s.folderlist(destlist)
s._msg("Deleting message %d in %s" % (uid, ds))
def deletingmessages(s, uidlist, destlist):
if s.verbose >= 0:
ds = s.folderlist(destlist)
s._msg("Deleting %d messages (%s) in %s" % \
(len(uidlist),
", ".join([str(u) for u in uidlist]),
ds))
def addingflags(s, uidlist, flags, destlist):
if s.verbose >= 0:
ds = s.folderlist(destlist)
s._msg("Adding flags %s to %d messages on %s" % \
(", ".join(flags), len(uidlist), ds))
def deletingflags(s, uidlist, flags, destlist):
if s.verbose >= 0:
ds = s.folderlist(destlist)
s._msg("Deleting flags %s to %d messages on %s" % \
(", ".join(flags), len(uidlist), ds))
################################################## Threads
def getThreadDebugLog(s, thread):
if s.debugmessages.has_key(thread):
message = "\nLast %d debug messages logged for %s prior to exception:\n"\
% (len(s.debugmessages[thread]), thread.getName())
message += "\n".join(s.debugmessages[thread])
else:
message = "\nNo debug messages were logged for %s." % \
thread.getName()
return message
def delThreadDebugLog(s, thread):
if s.debugmessages.has_key(thread):
del s.debugmessages[thread]
def getThreadExceptionString(s, thread):
message = "Thread '%s' terminated with exception:\n%s" % \
(thread.getName(), thread.getExitStackTrace())
message += "\n" + s.getThreadDebugLog(thread)
return message
def threadException(s, thread):
"""Called when a thread has terminated with an exception.
The argument is the ExitNotifyThread that has so terminated."""
s._msg(s.getThreadExceptionString(thread))
s.delThreadDebugLog(thread)
s.terminate(100)
def getMainExceptionString(s):
sbuf = StringIO()
traceback.print_exc(file = sbuf)
return "Main program terminated with exception:\n" + \
sbuf.getvalue() + "\n" + \
s.getThreadDebugLog(threading.currentThread())
def mainException(s):
s._msg(s.getMainExceptionString())
def terminate(s, exitstatus = 0, errortitle = None, errormsg = None):
"""Called to terminate the application."""
if errormsg <> None:
if errortitle <> None:
sys.stderr.write('ERROR: %s\n\n%s\n'%(errortitle, errormsg))
else:
sys.stderr.write('%s\n' % errormsg)
sys.exit(exitstatus)
def threadExited(s, thread):
"""Called when a thread has exited normally. Many UIs will
just ignore this."""
s.delThreadDebugLog(thread)
s.unregisterthread(thread)
################################################## Hooks
def callhook(s, msg):
if s.verbose >= 0:
s._msg(msg)
################################################## Other
def sleep(s, sleepsecs, siglistener):
"""This function does not actually output anything, but handles
the overall sleep, dealing with updates as necessary. It will,
however, call sleeping() which DOES output something.
Returns 0 if timeout expired, 1 if there is a request to cancel
the timer, and 2 if there is a request to abort the program."""
abortsleep = 0
while sleepsecs > 0 and not abortsleep:
try:
abortsleep = siglistener.get_nowait()
# retrieved signal while sleeping: 1 means immediately resynch, 2 means immediately die
except Empty:
# no signal
abortsleep = s.sleeping(1, sleepsecs)
sleepsecs -= 1
s.sleeping(0, 0) # Done sleeping.
return abortsleep
def sleeping(s, sleepsecs, remainingsecs):
"""Sleep for sleepsecs, remainingsecs to go.
If sleepsecs is 0, indicates we're done sleeping.
Return 0 for normal sleep, or 1 to indicate a request
to sync immediately."""
s._msg("Next refresh in %d seconds" % remainingsecs)
if sleepsecs > 0:
time.sleep(sleepsecs)
return 0