docker-offlineimap/offlineimap/accounts.py
Sebastian Spaeth 0ccf06d5e6 Implement clean CTRL-C termination
Previously, we would simply bail out in an ugly way, potentially leaving
temporary files around etc, or while writing status files. Hand SIGINT
and SIGTERM as an event to the Account class, and make that bail out
cleanly at predefined points. Stopping on ctrl-c can take a few seconds
(it will e.g. finish to transfer the ongoing message), but it will shut
down cleanly.

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
2012-01-04 19:31:27 +01:00

463 lines
18 KiB
Python

# Copyright (C) 2003-2011 John Goerzen & contributors
#
# 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
from offlineimap import mbnames, CustomConfig, OfflineImapError
from offlineimap.repository import Repository
from offlineimap.ui import getglobalui
from offlineimap.threadutil import InstanceLimitedThread
from subprocess import Popen, PIPE
from threading import Event
import os
from sys import exc_info
import traceback
try:
import fcntl
except:
pass # ok if this fails, we can do without
def getaccountlist(customconfig):
return customconfig.getsectionlist('Account')
def AccountListGenerator(customconfig):
return [Account(customconfig, accountname)
for accountname in getaccountlist(customconfig)]
def AccountHashGenerator(customconfig):
retval = {}
for item in AccountListGenerator(customconfig):
retval[item.getname()] = item
return retval
class Account(CustomConfig.ConfigHelperMixin):
"""Represents an account (ie. 2 repositories) to sync
Most of the time you will actually want to use the derived
:class:`accounts.SyncableAccount` which contains all functions used
for syncing an account."""
#signal gets set when we should stop looping
abort_soon_signal = Event()
#signal gets set on CTRL-C/SIGTERM
abort_NOW_signal = Event()
def __init__(self, config, name):
"""
:param config: Representing the offlineimap configuration file.
:type config: :class:`offlineimap.CustomConfig.CustomConfigParser`
:param name: A string denoting the name of the Account
as configured"""
self.config = config
self.name = name
self.metadatadir = config.getmetadatadir()
self.localeval = config.getlocaleval()
#Contains the current :mod:`offlineimap.ui`, and can be used for logging etc.
self.ui = getglobalui()
self.refreshperiod = self.getconffloat('autorefresh', 0.0)
self.quicknum = 0
if self.refreshperiod == 0.0:
self.refreshperiod = None
def getlocaleval(self):
return self.localeval
def getconfig(self):
return self.config
def getname(self):
return self.name
def __str__(self):
return self.name
def getaccountmeta(self):
return os.path.join(self.metadatadir, 'Account-' + self.name)
def getsection(self):
return 'Account ' + self.getname()
@classmethod
def set_abort_event(cls, config, signum):
"""Set skip sleep/abort event for all accounts
If we want to skip a current (or the next) sleep, or if we want
to abort an autorefresh loop, the main thread can use
set_abort_event() to send the corresponding signal. Signum = 1
implies that we want all accounts to abort or skip the current
or next sleep phase. Signum = 2 will end the autorefresh loop,
ie all accounts will return after they finished a sync. signum=3
means, abort NOW, e.g. on SIGINT or SIGTERM.
This is a class method, it will send the signal to all accounts.
"""
if signum == 1:
# resync signal, set config option for all accounts
for acctsection in getaccountlist(config):
config.set('Account ' + acctsection, "skipsleep", '1')
elif signum == 2:
# don't autorefresh anymore
cls.abort_soon_signal.set()
elif signum == 3:
# abort ASAP
cls.abort_NOW_signal.set()
def get_abort_event(self):
"""Checks if an abort signal had been sent
If the 'skipsleep' config option for this account had been set,
with `set_abort_event(config, 1)` it will get cleared in this
function. Ie, we will only skip one sleep and not all.
:returns: True, if the main thread had called
:meth:`set_abort_event` earlier, otherwise 'False'.
"""
skipsleep = self.getconfboolean("skipsleep", 0)
if skipsleep:
self.config.set(self.getsection(), "skipsleep", '0')
return skipsleep or Account.abort_soon_signal.is_set() or \
Account.abort_NOW_signal.is_set()
def sleeper(self):
"""Sleep if the account is set to autorefresh
:returns: 0:timeout expired, 1: canceled the timer,
2:request to abort the program,
100: if configured to not sleep at all.
"""
if not self.refreshperiod:
return 100
kaobjs = []
if hasattr(self, 'localrepos'):
kaobjs.append(self.localrepos)
if hasattr(self, 'remoterepos'):
kaobjs.append(self.remoterepos)
for item in kaobjs:
item.startkeepalive()
refreshperiod = int(self.refreshperiod * 60)
sleepresult = self.ui.sleep(refreshperiod, self)
# Cancel keepalive
for item in kaobjs:
item.stopkeepalive()
if sleepresult:
if Account.abort_soon_signal.is_set() or \
Account.abort_NOW_signal.is_set():
return 2
self.quicknum = 0
return 1
return 0
def serverdiagnostics(self):
"""Output diagnostics for all involved repositories"""
remote_repo = Repository(self, 'remote')
local_repo = Repository(self, 'local')
#status_repo = Repository(self, 'status')
self.ui.serverdiagnostics(remote_repo, 'Remote')
self.ui.serverdiagnostics(local_repo, 'Local')
#self.ui.serverdiagnostics(statusrepos, 'Status')
class SyncableAccount(Account):
"""A syncable email account connecting 2 repositories
Derives from :class:`accounts.Account` but contains the additional
functions :meth:`syncrunner`, :meth:`sync`, :meth:`syncfolders`,
used for syncing."""
def __init__(self, *args, **kwargs):
Account.__init__(self, *args, **kwargs)
self._lockfd = None
self._lockfilepath = os.path.join(self.config.getmetadatadir(),
"%s.lock" % self)
def lock(self):
"""Lock the account, throwing an exception if it is locked already"""
# Take a new-style per-account lock
self._lockfd = open(self._lockfilepath, 'w')
try:
fcntl.lockf(self._lockfd, fcntl.LOCK_EX|fcntl.LOCK_NB)
except NameError:
#fcntl not available (Windows), disable file locking... :(
pass
except IOError:
self._lockfd.close()
raise OfflineImapError("Could not lock account %s." % self,
OfflineImapError.ERROR.REPO)
def unlock(self):
"""Unlock the account, deleting the lock file"""
#If we own the lock file, delete it
if self._lockfd and not self._lockfd.closed:
self._lockfd.close()
try:
os.unlink(self._lockfilepath)
except OSError:
pass #Failed to delete for some reason.
def syncrunner(self):
self.ui.registerthread(self)
accountmetadata = self.getaccountmeta()
if not os.path.exists(accountmetadata):
os.mkdir(accountmetadata, 0700)
self.remoterepos = Repository(self, 'remote')
self.localrepos = Repository(self, 'local')
self.statusrepos = Repository(self, 'status')
# Loop account sync if needed (bail out after 3 failures)
looping = 3
while looping:
self.ui.acct(self)
try:
self.lock()
self.sync()
except (KeyboardInterrupt, SystemExit):
raise
except OfflineImapError, e:
# Stop looping and bubble up Exception if needed.
if e.severity >= OfflineImapError.ERROR.REPO:
if looping:
looping -= 1
if e.severity >= OfflineImapError.ERROR.CRITICAL:
raise
self.ui.error(e, exc_info()[2])
except Exception, e:
self.ui.error(e, exc_info()[2], msg = "While attempting to sync"
" account '%s'" % self)
else:
# after success sync, reset the looping counter to 3
if self.refreshperiod:
looping = 3
finally:
self.ui.acctdone(self)
self.unlock()
if looping and self.sleeper() >= 2:
looping = 0
def sync(self):
"""Synchronize the account once, then return
Assumes that `self.remoterepos`, `self.localrepos`, and
`self.statusrepos` has already been populated, so it should only
be called from the :meth:`syncrunner` function.
"""
folderthreads = []
hook = self.getconf('presynchook', '')
self.callhook(hook)
quickconfig = self.getconfint('quick', 0)
if quickconfig < 0:
quick = True
elif quickconfig > 0:
if self.quicknum == 0 or self.quicknum > quickconfig:
self.quicknum = 1
quick = False
else:
self.quicknum = self.quicknum + 1
quick = True
else:
quick = False
try:
remoterepos = self.remoterepos
localrepos = self.localrepos
statusrepos = self.statusrepos
# init repos with list of folders, so we have them (and the
# folder delimiter etc)
remoterepos.getfolders()
localrepos.getfolders()
statusrepos.getfolders()
# replicate the folderstructure between REMOTE to LOCAL
if not localrepos.getconfboolean('readonly', False):
self.ui.syncfolders(remoterepos, localrepos)
remoterepos.syncfoldersto(localrepos, statusrepos)
# iterate through all folders on the remote repo and sync
for remotefolder in remoterepos.getfolders():
# check for CTRL-C or SIGTERM
if Account.abort_NOW_signal.is_set(): break
if not remotefolder.sync_this:
self.ui.debug('', "Not syncing filtered remote folder '%s'"
"[%s]" % (remotefolder, remoterepos))
continue # Filtered out remote folder
thread = InstanceLimitedThread(\
instancename = 'FOLDER_' + self.remoterepos.getname(),
target = syncfolder,
name = "Folder %s [acc: %s]" % (remotefolder, self),
args = (self, remotefolder, quick))
thread.start()
folderthreads.append(thread)
# wait for all threads to finish
for thr in folderthreads:
thr.join()
mbnames.write()
localrepos.forgetfolders()
remoterepos.forgetfolders()
except:
#error while syncing. Drop all connections that we have, they
#might be bogus by now (e.g. after suspend)
localrepos.dropconnections()
remoterepos.dropconnections()
raise
else:
# sync went fine. Hold or drop depending on config
localrepos.holdordropconnections()
remoterepos.holdordropconnections()
hook = self.getconf('postsynchook', '')
self.callhook(hook)
def callhook(self, cmd):
# check for CTRL-C or SIGTERM and run postsynchook
if Account.abort_NOW_signal.is_set():
return
if not cmd:
return
try:
self.ui.callhook("Calling hook: " + cmd)
p = Popen(cmd, shell=True,
stdin=PIPE, stdout=PIPE, stderr=PIPE,
close_fds=True)
r = p.communicate()
self.ui.callhook("Hook stdout: %s\nHook stderr:%s\n" % r)
self.ui.callhook("Hook return code: %d" % p.returncode)
except (KeyboardInterrupt, SystemExit):
raise
except Exception, e:
self.ui.error(e, exc_info()[2], msg = "Calling hook")
def syncfolder(account, remotefolder, quick):
"""This function is called as target for the
InstanceLimitedThread invokation in SyncableAccount.
Filtered folders on the remote side will not invoke this function."""
remoterepos = account.remoterepos
localrepos = account.localrepos
statusrepos = account.statusrepos
ui = getglobalui()
ui.registerthread(account)
try:
# Load local folder.
localfolder = localrepos.\
getfolder(remotefolder.getvisiblename().\
replace(remoterepos.getsep(), localrepos.getsep()))
#Filtered folders on the remote side will not invoke this
#function, but we need to NOOP if the local folder is filtered
#out too:
if not localfolder.sync_this:
ui.debug('', "Not syncing filtered local folder '%s'" \
% localfolder)
return
# Write the mailboxes
mbnames.add(account.name, localfolder.getvisiblename())
# Load status folder.
statusfolder = statusrepos.getfolder(remotefolder.getvisiblename().\
replace(remoterepos.getsep(),
statusrepos.getsep()))
if localfolder.getuidvalidity() == None:
# This is a new folder, so delete the status cache to be sure
# we don't have a conflict.
statusfolder.deletemessagelist()
statusfolder.cachemessagelist()
if quick:
if not localfolder.quickchanged(statusfolder) \
and not remotefolder.quickchanged(statusfolder):
ui.skippingfolder(remotefolder)
localrepos.restore_atime()
return
# Load local folder
ui.syncingfolder(remoterepos, remotefolder, localrepos, localfolder)
ui.loadmessagelist(localrepos, localfolder)
localfolder.cachemessagelist()
ui.messagelistloaded(localrepos, localfolder, localfolder.getmessagecount())
# If either the local or the status folder has messages and there is a UID
# validity problem, warn and abort. If there are no messages, UW IMAPd
# loses UIDVALIDITY. But we don't really need it if both local folders are
# empty. So, in that case, just save it off.
if localfolder.getmessagecount() or statusfolder.getmessagecount():
if not localfolder.isuidvalidityok():
ui.validityproblem(localfolder)
localrepos.restore_atime()
return
if not remotefolder.isuidvalidityok():
ui.validityproblem(remotefolder)
localrepos.restore_atime()
return
else:
localfolder.saveuidvalidity()
remotefolder.saveuidvalidity()
# Load remote folder.
ui.loadmessagelist(remoterepos, remotefolder)
remotefolder.cachemessagelist()
ui.messagelistloaded(remoterepos, remotefolder,
remotefolder.getmessagecount())
# Synchronize remote changes.
if not localrepos.getconfboolean('readonly', False):
ui.syncingmessages(remoterepos, remotefolder, localrepos, localfolder)
remotefolder.syncmessagesto(localfolder, statusfolder)
else:
ui.debug('imap', "Not syncing to read-only repository '%s'" \
% localrepos.getname())
# Synchronize local changes
if not remoterepos.getconfboolean('readonly', False):
ui.syncingmessages(localrepos, localfolder, remoterepos, remotefolder)
localfolder.syncmessagesto(remotefolder, statusfolder)
else:
ui.debug('', "Not syncing to read-only repository '%s'" \
% remoterepos.getname())
statusfolder.save()
localrepos.restore_atime()
except (KeyboardInterrupt, SystemExit):
raise
except OfflineImapError, e:
# bubble up severe Errors, skip folder otherwise
if e.severity > OfflineImapError.ERROR.FOLDER:
raise
else:
#if the initial localfolder assignement bailed out, the localfolder var will not be available, so we need
ui.error(e, exc_info()[2], msg = "Aborting sync, folder '%s' "
"[acc: '%s']" % (
remotefolder.getvisiblename().\
replace(remoterepos.getsep(), localrepos.getsep()),
account))
# we reconstruct foldername above rather than using
# localfolder, as the localfolder var is not
# available if assignment fails.
except Exception, e:
ui.error(e, msg = "ERROR in syncfolder for %s folder %s: %s" % \
(account, remotefolder.getvisiblename(),
traceback.format_exc()))