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 foldermatchre = re.compile(',FMD5=([0-9a-f]{32})')
  26 uidmatchre = re.compile(',U=(\d+)')
  27 flagmatchre = re.compile(':.*2,([A-Z]+)')
  28
  29 timeseq = 0
  30 lasttime = long(0)
  31 timelock = Lock()
  32
  33 def gettimeseq():
  34     global lasttime, timeseq, timelock
  35     timelock.acquire()
  36     try:
  37         thistime = long(time.time())
  38         if thistime == lasttime:
  39             timeseq += 1
  40             return (thistime, timeseq)
  41         else:
  42             lasttime = thistime
  43             timeseq = 0
  44             return (thistime, timeseq)
  45     finally:
  46         timelock.release()
  47
  48 class MaildirFolder(BaseFolder):
  49     def __init__(self, root, name, sep, repository, accountname):
  50         self.name = name
  51         self.root = root
  52         self.sep = sep
  53         self.messagelist = None
  54         self.repository = repository
  55         self.accountname = accountname
  56         BaseFolder.__init__(self)
  57
  58     def getaccountname(self):
  59         return self.accountname
  60
  61     def getfullname(self):
  62         return os.path.join(self.getroot(), self.getname())
  63
  64     def getuidvalidity(self):
  65         """Maildirs have no notion of uidvalidity, so we just return a magic
  66         token."""
  67         return 42
  68
  69     def _scanfolder(self):
  70         """Cache the message list.  Maildir flags are:
  71         R (replied)
  72         S (seen)
  73         T (trashed)
  74         D (draft)
  75         F (flagged)
  76         and must occur in ASCII order."""
  77         retval = {}
  78         files = []
  79         nouidcounter = -1               # Messages without UIDs get
  80                                         # negative UID numbers.
  81         for dirannex in ['new', 'cur']:
  82             fulldirname = os.path.join(self.getfullname(), dirannex)
  83             files.extend([os.path.join(fulldirname, filename) for
  84                           filename in os.listdir(fulldirname)])
  85         for file in files:
  86             messagename = os.path.basename(file)
  87             foldermatch = foldermatchre.search(messagename)
  88             if (not foldermatch) or \
  89                md5.new(self.getvisiblename()).hexdigest() \
  90                != foldermatch.group(1):
  91                 # If there is no folder MD5 specified, or if it mismatches,
  92                 # assume it is a foreign (new) message and generate a
  93                 # negative uid for it
  94                 uid = nouidcounter
  95                 nouidcounter -= 1
  96             else:                       # It comes from our folder.
  97                 uidmatch = uidmatchre.search(messagename)
  98                 uid = None
  99                 if not uidmatch:
 100                     uid = nouidcounter
 101                     nouidcounter -= 1
 102                 else:
 103                     uid = long(uidmatch.group(1))
 104             flagmatch = flagmatchre.search(messagename)
 105             flags = []
 106             if flagmatch:
 107                 flags = [x for x in flagmatch.group(1)]
 108             flags.sort()
 109             retval[uid] = {'uid': uid,
 110                            'flags': flags,
 111                            'filename': file}
 112         return retval
 113
 114     def cachemessagelist(self):
 115         self.messagelist = self._scanfolder()
 116
 117     def getmessagelist(self):
 118         return self.messagelist
 119
 120     def getmessage(self, uid):
 121         filename = self.messagelist[uid]['filename']
 122         file = open(filename, 'rt')
 123         retval = file.read()
 124         file.close()
 125         return retval.replace("\r\n", "\n")
 126
 127     def getmessagetime( self, uid ):
 128         filename = self.messagelist[uid]['filename']
 129         st = os.stat(filename)
 130         return st.st_mtime
 131
 132     def savemessage(self, uid, content, flags, rtime):
 133         # This function only ever saves to tmp/,
 134         # but it calls savemessageflags() to actually save to cur/ or new/.
 135         ui = UIBase.getglobalui()
 136         ui.debug('maildir', 'savemessage: called to write with flags %s and content %s' % \
 137                  (repr(flags), repr(content)))
 138         if uid < 0:
 139             # We cannot assign a new uid.
 140             return uid
 141         if uid in self.messagelist:
 142             # We already have it.
 143             self.savemessageflags(uid, flags)
 144             return uid
 145
 146         # Otherwise, save the message in tmp/ and then call savemessageflags()
 147         # to give it a permanent home.
 148         tmpdir = os.path.join(self.getfullname(), 'tmp')
 149         messagename = None
 150         attempts = 0
 151         while 1:
 152             if attempts > 15:
 153                 raise IOError, "Couldn't write to file %s" % messagename
 154             timeval, timeseq = gettimeseq()
 155             messagename = '%d_%d.%d.%s,U=%d,FMD5=%s' % \
 156                           (timeval,
 157                            timeseq,
 158                            os.getpid(),
 159                            socket.gethostname(),
 160                            uid,
 161                            md5.new(self.getvisiblename()).hexdigest())
 162             if os.path.exists(os.path.join(tmpdir, messagename)):
 163                 time.sleep(2)
 164                 attempts += 1
 165             else:
 166                 break
 167         tmpmessagename = messagename.split(',')[0]
 168         ui.debug('maildir', 'savemessage: using temporary name %s' % tmpmessagename)
 169         file = open(os.path.join(tmpdir, tmpmessagename), "wt")
 170         file.write(content)
 171
 172         # Make sure the data hits the disk
 173         file.flush()
 174         os.fsync(file.fileno())
 175
 176         file.close()
 177         if rtime != None:
 178             os.utime(os.path.join(tmpdir,tmpmessagename), (rtime,rtime))
 179         ui.debug('maildir', 'savemessage: moving from %s to %s' % \
 180                  (tmpmessagename, messagename))
 181         if tmpmessagename != messagename: # then rename it
 182             os.link(os.path.join(tmpdir, tmpmessagename),
 183                     os.path.join(tmpdir, messagename))
 184             os.unlink(os.path.join(tmpdir, tmpmessagename))
 185
 186         try:
 187             # fsync the directory (safer semantics in Linux)
 188             fd = os.open(tmpdir, os.O_RDONLY)
 189             os.fsync(fd)
 190             os.close(fd)
 191         except:
 192             pass
 193
 194         self.messagelist[uid] = {'uid': uid, 'flags': [],
 195                                  'filename': os.path.join(tmpdir, messagename)}
 196         self.savemessageflags(uid, flags)
 197         ui.debug('maildir', 'savemessage: returning uid %d' % uid)
 198         return uid
 199
 200     def getmessageflags(self, uid):
 201         return self.messagelist[uid]['flags']
 202
 203     def savemessageflags(self, uid, flags):
 204         oldfilename = self.messagelist[uid]['filename']
 205         newpath, newname = os.path.split(oldfilename)
 206         tmpdir = os.path.join(self.getfullname(), 'tmp')
 207         if 'S' in flags:
 208             # If a message has been seen, it goes into the cur
 209             # directory.  CR debian#152482, [complete.org #4]
 210             newpath = os.path.join(self.getfullname(), 'cur')
 211         else:
 212             newpath = os.path.join(self.getfullname(), 'new')
 213         infostr = ':'
 214         infomatch = re.search('(:.*)$', newname)
 215         if infomatch:                   # If the info string is present..
 216             infostr = infomatch.group(1)
 217             newname = newname.split(':')[0] # Strip off the info string.
 218         infostr = re.sub('2,[A-Z]*', '', infostr)
 219         flags.sort()
 220         infostr += '2,' + ''.join(flags)
 221         newname += infostr
 222
 223         newfilename = os.path.join(newpath, newname)
 224         if (newfilename != oldfilename):
 225             os.rename(oldfilename, newfilename)
 226             self.messagelist[uid]['flags'] = flags
 227             self.messagelist[uid]['filename'] = newfilename
 228
 229         # By now, the message had better not be in tmp/ land!
 230         final_dir, final_name = os.path.split(self.messagelist[uid]['filename'])
 231         assert final_dir != tmpdir
 232
 233     def deletemessage(self, uid):
 234         if not uid in self.messagelist:
 235             return
 236         filename = self.messagelist[uid]['filename']
 237         try:
 238             os.unlink(filename)
 239         except OSError:
 240             # Can't find the file -- maybe already deleted?
 241             newmsglist = self._scanfolder()
 242             if uid in newmsglist:       # Nope, try new filename.
 243                 os.unlink(newmsglist[uid]['filename'])
 244             # Yep -- return.
 245         del(self.messagelist[uid])
 246