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