code.delx.au - offlineimap/blob - offlineimap/folder/Maildir.py

   1 # Maildir folder support
   2 # Copyright (C) 2002 - 2007 John Goerzen
   3 # <jgoerzen@complete.org>
   4 #
   5 #    This program is free software; you can redistribute it and/or modify
   6 #    it under the terms of the GNU General Public License as published by
   7 #    the Free Software Foundation; either version 2 of the License, or
   8 #    (at your option) any later version.
   9 #
  10 #    This program is distributed in the hope that it will be useful,
  11 #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 #    GNU General Public License for more details.
  14 #
  15 #    You should have received a copy of the GNU General Public License
  16 #    along with this program; if not, write to the Free Software
  17 #    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  18
  19 import os.path, os, re, time, socket
  20 from Base import BaseFolder
  21 from offlineimap import imaputil
  22 from offlineimap.ui import UIBase
  23 from threading import Lock
  24
  25 try:
  26     from hashlib import md5
  27 except ImportError:
  28     from md5 import md5
  29
  30 uidmatchre = re.compile(',U=(\d+)')
  31 flagmatchre = re.compile(':.*2,([A-Z]+)')
  32
  33 timeseq = 0
  34 lasttime = long(0)
  35 timelock = Lock()
  36
  37 def gettimeseq():
  38     global lasttime, timeseq, timelock
  39     timelock.acquire()
  40     try:
  41         thistime = long(time.time())
  42         if thistime == lasttime:
  43             timeseq += 1
  44             return (thistime, timeseq)
  45         else:
  46             lasttime = thistime
  47             timeseq = 0
  48             return (thistime, timeseq)
  49     finally:
  50         timelock.release()
  51
  52 class MaildirFolder(BaseFolder):
  53     def __init__(self, root, name, sep, repository, accountname, config):
  54         self.name = name
  55         self.config = config
  56         self.dofsync = config.getdefaultboolean("general", "fsync", True)
  57         self.root = root
  58         self.sep = sep
  59         self.messagelist = None
  60         self.repository = repository
  61         self.accountname = accountname
  62         BaseFolder.__init__(self)
  63
  64     def getaccountname(self):
  65         return self.accountname
  66
  67     def getfullname(self):
  68         return os.path.join(self.getroot(), self.getname())
  69
  70     def getuidvalidity(self):
  71         """Maildirs have no notion of uidvalidity, so we just return a magic
  72         token."""
  73         return 42
  74
  75     def _scanfolder(self):
  76         """Cache the message list.  Maildir flags are:
  77         R (replied)
  78         S (seen)
  79         T (trashed)
  80         D (draft)
  81         F (flagged)
  82         and must occur in ASCII order."""
  83         retval = {}
  84         files = []
  85         nouidcounter = -1               # Messages without UIDs get
  86                                         # negative UID numbers.
  87         foldermd5 = md5(self.getvisiblename()).hexdigest()
  88         folderstr = ',FMD5=' + foldermd5
  89         for dirannex in ['new', 'cur']:
  90             fulldirname = os.path.join(self.getfullname(), dirannex)
  91             files.extend([os.path.join(fulldirname, filename) for
  92                           filename in os.listdir(fulldirname)])
  93         for file in files:
  94             messagename = os.path.basename(file)
  95             foldermatch = messagename.find(folderstr) != -1
  96             if not foldermatch:
  97                 # If there is no folder MD5 specified, or if it mismatches,
  98                 # assume it is a foreign (new) message and generate a
  99                 # negative uid for it
 100                 uid = nouidcounter
 101                 nouidcounter -= 1
 102             else:                       # It comes from our folder.
 103                 uidmatch = uidmatchre.search(messagename)
 104                 uid = None
 105                 if not uidmatch:
 106                     uid = nouidcounter
 107                     nouidcounter -= 1
 108                 else:
 109                     uid = long(uidmatch.group(1))
 110             flagmatch = flagmatchre.search(messagename)
 111             flags = []
 112             if flagmatch:
 113                 flags = [x for x in flagmatch.group(1)]
 114             flags.sort()
 115             retval[uid] = {'uid': uid,
 116                            'flags': flags,
 117                            'filename': file}
 118         return retval
 119
 120     def quickchanged(self, statusfolder):
 121         self.cachemessagelist()
 122         savedmessages = statusfolder.getmessagelist()
 123         if len(self.messagelist) != len(savedmessages):
 124             return True
 125         for uid in self.messagelist.keys():
 126             if uid not in savedmessages:
 127                 return True
 128             if self.messagelist[uid]['flags'] != savedmessages[uid]['flags']:
 129                 return True
 130         return False
 131
 132     def cachemessagelist(self):
 133         if self.messagelist is None:
 134             self.messagelist = self._scanfolder()
 135
 136     def getmessagelist(self):
 137         return self.messagelist
 138
 139     def getmessage(self, uid):
 140         filename = self.messagelist[uid]['filename']
 141         file = open(filename, 'rt')
 142         retval = file.read()
 143         file.close()
 144         return retval.replace("\r\n", "\n")
 145
 146     def getmessagetime( self, uid ):
 147         filename = self.messagelist[uid]['filename']
 148         st = os.stat(filename)
 149         return st.st_mtime
 150
 151     def savemessage(self, uid, content, flags, rtime):
 152         # This function only ever saves to tmp/,
 153         # but it calls savemessageflags() to actually save to cur/ or new/.
 154         ui = UIBase.getglobalui()
 155         ui.debug('maildir', 'savemessage: called to write with flags %s and content %s' % \
 156                  (repr(flags), repr(content)))
 157         if uid < 0:
 158             # We cannot assign a new uid.
 159             return uid
 160         if uid in self.messagelist:
 161             # We already have it.
 162             self.savemessageflags(uid, flags)
 163             return uid
 164
 165         # Otherwise, save the message in tmp/ and then call savemessageflags()
 166         # to give it a permanent home.
 167         tmpdir = os.path.join(self.getfullname(), 'tmp')
 168         messagename = None
 169         attempts = 0
 170         while 1:
 171             if attempts > 15:
 172                 raise IOError, "Couldn't write to file %s" % messagename
 173             timeval, timeseq = gettimeseq()
 174             messagename = '%d_%d.%d.%s,U=%d,FMD5=%s' % \
 175                           (timeval,
 176                            timeseq,
 177                            os.getpid(),
 178                            socket.gethostname(),
 179                            uid,
 180                            md5(self.getvisiblename()).hexdigest())
 181             if os.path.exists(os.path.join(tmpdir, messagename)):
 182                 time.sleep(2)
 183                 attempts += 1
 184             else:
 185                 break
 186         tmpmessagename = messagename.split(',')[0]
 187         ui.debug('maildir', 'savemessage: using temporary name %s' % tmpmessagename)
 188         file = open(os.path.join(tmpdir, tmpmessagename), "wt")
 189         file.write(content)
 190
 191         # Make sure the data hits the disk
 192         file.flush()
 193         if self.dofsync:
 194             os.fsync(file.fileno())
 195
 196         file.close()
 197         if rtime != None:
 198             os.utime(os.path.join(tmpdir,tmpmessagename), (rtime,rtime))
 199         ui.debug('maildir', 'savemessage: moving from %s to %s' % \
 200                  (tmpmessagename, messagename))
 201         if tmpmessagename != messagename: # then rename it
 202             os.link(os.path.join(tmpdir, tmpmessagename),
 203                     os.path.join(tmpdir, messagename))
 204             os.unlink(os.path.join(tmpdir, tmpmessagename))
 205
 206         if self.dofsync:
 207             try:
 208                 # fsync the directory (safer semantics in Linux)
 209                 fd = os.open(tmpdir, os.O_RDONLY)
 210                 os.fsync(fd)
 211                 os.close(fd)
 212             except:
 213                 pass
 214
 215         self.messagelist[uid] = {'uid': uid, 'flags': [],
 216                                  'filename': os.path.join(tmpdir, messagename)}
 217         self.savemessageflags(uid, flags)
 218         ui.debug('maildir', 'savemessage: returning uid %d' % uid)
 219         return uid
 220
 221     def getmessageflags(self, uid):
 222         return self.messagelist[uid]['flags']
 223
 224     def savemessageflags(self, uid, flags):
 225         oldfilename = self.messagelist[uid]['filename']
 226         newpath, newname = os.path.split(oldfilename)
 227         tmpdir = os.path.join(self.getfullname(), 'tmp')
 228         if 'S' in flags:
 229             # If a message has been seen, it goes into the cur
 230             # directory.  CR debian#152482, [complete.org #4]
 231             newpath = os.path.join(self.getfullname(), 'cur')
 232         else:
 233             newpath = os.path.join(self.getfullname(), 'new')
 234         infostr = ':'
 235         infomatch = re.search('(:.*)$', newname)
 236         if infomatch:                   # If the info string is present..
 237             infostr = infomatch.group(1)
 238             newname = newname.split(':')[0] # Strip off the info string.
 239         infostr = re.sub('2,[A-Z]*', '', infostr)
 240         flags.sort()
 241         infostr += '2,' + ''.join(flags)
 242         newname += infostr
 243
 244         newfilename = os.path.join(newpath, newname)
 245         if (newfilename != oldfilename):
 246             os.rename(oldfilename, newfilename)
 247             self.messagelist[uid]['flags'] = flags
 248             self.messagelist[uid]['filename'] = newfilename
 249
 250         # By now, the message had better not be in tmp/ land!
 251         final_dir, final_name = os.path.split(self.messagelist[uid]['filename'])
 252         assert final_dir != tmpdir
 253
 254     def deletemessage(self, uid):
 255         if not uid in self.messagelist:
 256             return
 257         filename = self.messagelist[uid]['filename']
 258         try:
 259             os.unlink(filename)
 260         except OSError:
 261             # Can't find the file -- maybe already deleted?
 262             newmsglist = self._scanfolder()
 263             if uid in newmsglist:       # Nope, try new filename.
 264                 os.unlink(newmsglist[uid]['filename'])
 265             # Yep -- return.
 266         del(self.messagelist[uid])
 267