docker-offlineimap/offlineimap/folder/LocalStatus.py
John Goerzen 4f54887265 Improve filesystem flushing semantics
fsync the Maildir file, its final directory when writing a new message.

fsync the localstatus file and its final directory when writing the 
local status cache.

This should reduce duplication in the event of hardware trouble.

fixes #8

see thread at http://lists.complete.org/offlineimap@complete.org/2007/03/threads.html.gz
2007-03-28 21:23:18 +01:00

139 lines
4.1 KiB
Python

# Local status cache virtual folder
# Copyright (C) 2002 - 2007 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
from Base import BaseFolder
import os, threading
magicline = "OFFLINEIMAP LocalStatus CACHE DATA - DO NOT MODIFY - FORMAT 1"
class LocalStatusFolder(BaseFolder):
def __init__(self, root, name, repository, accountname):
self.name = name
self.root = root
self.sep = '.'
self.filename = os.path.join(root, name)
self.filename = repository.getfolderfilename(name)
self.messagelist = None
self.repository = repository
self.savelock = threading.Lock()
self.doautosave = 1
self.accountname = accountname
BaseFolder.__init__(self)
def getaccountname(self):
return self.accountname
def storesmessages(self):
return 0
def isnewfolder(self):
return not os.path.exists(self.filename)
def getname(self):
return self.name
def getroot(self):
return self.root
def getsep(self):
return self.sep
def getfullname(self):
return self.filename
def deletemessagelist(self):
if not self.isnewfolder():
os.unlink(self.filename)
def cachemessagelist(self):
if self.isnewfolder():
self.messagelist = {}
return
file = open(self.filename, "rt")
self.messagelist = {}
line = file.readline().strip()
assert(line == magicline)
for line in file.xreadlines():
line = line.strip()
uid, flags = line.split(':')
uid = long(uid)
flags = [x for x in flags]
self.messagelist[uid] = {'uid': uid, 'flags': flags}
file.close()
def autosave(self):
if self.doautosave:
self.save()
def save(self):
self.savelock.acquire()
try:
file = open(self.filename + ".tmp", "wt")
file.write(magicline + "\n")
for msg in self.messagelist.values():
flags = msg['flags']
flags.sort()
flags = ''.join(flags)
file.write("%s:%s\n" % (msg['uid'], flags))
file.flush()
os.fsync(file.fileno())
file.close()
os.rename(self.filename + ".tmp", self.filename)
try:
fd = os.open(os.path.dirname(self.filename), os.O_RDONLY)
os.fsync(fd)
os.close(fd)
except:
pass
finally:
self.savelock.release()
def getmessagelist(self):
return self.messagelist
def savemessage(self, uid, content, flags, rtime):
if uid < 0:
# We cannot assign a uid.
return uid
if uid in self.messagelist: # already have it
self.savemessageflags(uid, flags)
return uid
self.messagelist[uid] = {'uid': uid, 'flags': flags, 'time': rtime}
self.autosave()
return uid
def getmessageflags(self, uid):
return self.messagelist[uid]['flags']
def getmessagetime(self, uid):
return self.messagelist[uid]['time']
def savemessageflags(self, uid, flags):
self.messagelist[uid]['flags'] = flags
self.autosave()
def deletemessage(self, uid):
if not uid in self.messagelist:
return
del(self.messagelist[uid])
self.autosave()