offlineimap/offlineimap/imaplibutil.py

# imaplib utilities
# Copyright (C) 2002-2007 John Goerzen <jgoerzen@complete.org>
#                    2010 Sebastian Spaeth <Sebastian@SSpaeth.de>
#    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

import os
import fcntl
import re
import socket
import time
import subprocess
from offlineimap.ui import getglobalui
import threading
from offlineimap import OfflineImapError
from offlineimap.imaplib2 import IMAP4, IMAP4_SSL, zlib, IMAP4_PORT, InternalDate, Mon2num

try:
    import ssl
except ImportError:
    #fails on python <2.6
    pass

class UsefulIMAPMixIn:
    def getselectedfolder(self):
        if self.state == 'SELECTED':
            return self.mailbox
        return None

    def select(self, mailbox='INBOX', readonly=None, force = 0):
        """Selects a mailbox on the IMAP server

        :returns: 'OK' on success, nothing if the folder was already
        selected or raises an :exc:`OfflineImapError`"""
        if (not force) and self.getselectedfolder() == mailbox \
           and self.is_readonly == readonly:
            # No change; return.
            return
        # Wipe out all old responses, to maintain semantics with old imaplib2
        del self.untagged_responses[:]
        try:
            result = self.__class__.__bases__[1].select(self, mailbox, readonly)
        except self.abort, e:
            # self.abort is raised when we are supposed to retry
            errstr = "Server '%s' closed connection, error on SELECT '%s'. Ser"\
                "ver said: %s" % (self.host, mailbox, e.args[0])
            severity = OfflineImapError.ERROR.FOLDER_RETRY
            raise OfflineImapError(errstr, severity) 
        if result[0] != 'OK':
            #in case of error, bail out with OfflineImapError
            errstr = "Error SELECTing mailbox '%s', server reply:\n%s" %\
                (mailbox, result)
            severity = OfflineImapError.ERROR.FOLDER
            raise OfflineImapError(errstr, severity) 
        return result

    def _mesg(self, s, tn=None, secs=None):
        new_mesg(self, s, tn, secs)

class IMAP4_Tunnel(UsefulIMAPMixIn, IMAP4):
    """IMAP4 client class over a tunnel

    Instantiate with: IMAP4_Tunnel(tunnelcmd)

    tunnelcmd -- shell command to generate the tunnel.
    The result will be in PREAUTH stage."""

    def __init__(self, tunnelcmd, **kwargs):
        IMAP4.__init__(self, tunnelcmd, **kwargs)

    def open(self, host, port):
        """The tunnelcmd comes in on host!"""
        self.host = host
        self.process = subprocess.Popen(host, shell=True, close_fds=True,
                        stdin=subprocess.PIPE, stdout=subprocess.PIPE)
        (self.outfd, self.infd) = (self.process.stdin, self.process.stdout)
        # imaplib2 polls on this fd
        self.read_fd = self.infd.fileno()

        self.set_nonblocking(self.read_fd)

    def set_nonblocking(self, fd):
        "Mark fd as nonblocking"
        # get the file's current flag settings
        fl = fcntl.fcntl(fd, fcntl.F_GETFL)
        # clear non-blocking mode from flags
        fl = fl & ~os.O_NONBLOCK
        fcntl.fcntl(fd, fcntl.F_SETFL, fl)

    def read(self, size):
        """data = read(size)
        Read at most 'size' bytes from remote."""

        if self.decompressor is None:
            return os.read(self.read_fd, size)

        if self.decompressor.unconsumed_tail:
            data = self.decompressor.unconsumed_tail
        else:
            data = os.read(self.read_fd, 8192)

        return self.decompressor.decompress(data, size)

    def send(self, data):
        if self.compressor is not None:
            data = self.compressor.compress(data)
            data += self.compressor.flush(zlib.Z_SYNC_FLUSH)

        self.outfd.write(data)


    def shutdown(self):
        self.infd.close()
        self.outfd.close()
        self.process.wait()


def new_mesg(self, s, tn=None, secs=None):
            if secs is None:
                secs = time.time()
            if tn is None:
                tn = threading.currentThread().getName()
            tm = time.strftime('%M:%S', time.localtime(secs))
            getglobalui().debug('imap', '  %s.%02d %s %s' % (tm, (secs*100)%100, tn, s))


class WrappedIMAP4_SSL(UsefulIMAPMixIn, IMAP4_SSL):
    """Improved version of imaplib.IMAP4_SSL overriding select()"""
    pass


class WrappedIMAP4(UsefulIMAPMixIn, IMAP4):
    """Improved version of imaplib.IMAP4 overriding select()"""
    pass


def Internaldate2epoch(resp):
    """Convert IMAP4 INTERNALDATE to UT.

    Returns seconds since the epoch.
    """

    mo = InternalDate.match(resp)
    if not mo:
        return None

    mon = Mon2num[mo.group('mon')]
    zonen = mo.group('zonen')

    day = int(mo.group('day'))
    year = int(mo.group('year'))
    hour = int(mo.group('hour'))
    min = int(mo.group('min'))
    sec = int(mo.group('sec'))
    zoneh = int(mo.group('zoneh'))
    zonem = int(mo.group('zonem'))

    # INTERNALDATE timezone must be subtracted to get UT

    zone = (zoneh*60 + zonem)*60
    if zonen == '-':
        zone = -zone

    tt = (year, mon, day, hour, min, sec, -1, -1, -1)

    return time.mktime(tt)