VirtualMailManager/alias.py
branchv0.6.x
changeset 320 011066435e6f
parent 316 31d8931dc535
child 322 94bd10e237e5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/VirtualMailManager/alias.py	Wed Jul 28 02:08:03 2010 +0000
@@ -0,0 +1,164 @@
+# -*- coding: UTF-8 -*-
+# Copyright (c) 2007 - 2010, Pascal Volk
+# See COPYING for distribution information.
+"""
+    VirtualMailManager.alias
+    ~~~~~~~~~~~~~~~~~~~~~~~~
+
+    Virtual Mail Manager's Alias class to manage e-mail aliases.
+"""
+
+from VirtualMailManager.domain import get_gid
+from VirtualMailManager.emailaddress import EmailAddress
+from VirtualMailManager.errors import AliasError as AErr
+from VirtualMailManager.ext.postconf import Postconf
+from VirtualMailManager.pycompat import all
+from VirtualMailManager.constants import \
+     ALIAS_EXCEEDS_EXPANSION_LIMIT, NO_SUCH_ALIAS, NO_SUCH_DOMAIN
+
+
+_ = lambda msg: msg
+cfg_dget = lambda option: None
+
+
+class Alias(object):
+    """Class to manage e-mail aliases."""
+    __slots__ = ('_addr', '_dests', '_gid', '_dbh')
+
+    def __init__(self, dbh, address):
+        assert isinstance(address, EmailAddress)
+        self._addr = address
+        self._dbh = dbh
+        self._gid = get_gid(self._dbh, self._addr.domainname)
+        if not self._gid:
+            raise AErr(_(u"The domain '%s' doesn't exist.") %
+                       self._addr.domainname, NO_SUCH_DOMAIN)
+        self._dests = []
+
+        self.__load_dests()
+
+    def __load_dests(self):
+        """Loads all known destination addresses into the _dests list."""
+        dbc = self._dbh.cursor()
+        dbc.execute('SELECT destination FROM alias WHERE gid = %s AND '
+                    'address = %s', self._gid, self._addr.localpart)
+        dests = dbc.fetchall()
+        if dbc.rowcount > 0:
+            self._dests.extend(EmailAddress(dest[0]) for dest in dests)
+        dbc.close()
+
+    def __check_expansion(self, count_new):
+        """Checks the current expansion limit of the alias."""
+        postconf = Postconf(cfg_dget('bin.postconf'))
+        limit = long(postconf.read('virtual_alias_expansion_limit'))
+        dcount = len(self._dests)
+        failed = False
+        if dcount == limit or dcount + count_new > limit:
+            failed = True
+            errmsg = _(
+u"""Can't add %(count_new)i new destination(s) to alias '%(address)s'.
+Currently this alias expands into %(count)i/%(limit)i recipients.
+%(count_new)i additional destination(s) will render this alias unusable.
+Hint: Increase Postfix' virtual_alias_expansion_limit""")
+        elif dcount > limit:
+            failed = True
+            errmsg = _(
+u"""Can't add %(count_new)i new destination(s) to alias '%(address)s'.
+This alias already exceeds its expansion limit (%(count)i/%(limit)i).
+So its unusable, all messages addressed to this alias will be bounced.
+Hint: Delete some destination addresses.""")
+        if failed:
+            raise AErr(errmsg % {'address': self._addr, 'count': dcount,
+                                 'limit': limit, 'count_new': count_new},
+                       ALIAS_EXCEEDS_EXPANSION_LIMIT)
+
+    def __delete(self, destination=None):
+        """Deletes a destination from the alias, if ``destination`` is
+        not ``None``.  If ``destination`` is None, the alias with all
+        its destination addresses will be deleted.
+
+        """
+        dbc = self._dbh.cursor()
+        if not destination:
+            dbc.execute('DELETE FROM alias WHERE gid = %s AND address = %s',
+                        self._gid, self._addr.localpart)
+        else:
+            dbc.execute('DELETE FROM alias WHERE gid = %s AND address = %s '
+                        'AND destination = %s', self._gid,
+                        self._addr.localpart, str(destination))
+        if dbc.rowcount > 0:
+            self._dbh.commit()
+        dbc.close()
+
+    def __len__(self):
+        """Returns the number of destinations of the alias."""
+        return len(self._dests)
+
+    @property
+    def address(self):
+        """The Alias' EmailAddress instance."""
+        return self._addr
+
+    def add_destinations(self, destinations, warnings=None):
+        """Adds the `EmailAddress`es from *destinations* list to the
+        destinations of the alias.
+
+        Destinations, that are already assigned to the alias, will be
+        removed from *destinations*.  When done, this method will return
+        a set with all destinations, that were saved in the database.
+        """
+        destinations = set(destinations)
+        assert destinations and \
+                all(isinstance(dest, EmailAddress) for dest in destinations)
+        if not warnings is None:
+            assert isinstance(warnings, list)
+        if self._addr in destinations:
+            destinations.remove(self._addr)
+            if not warnings is None:
+                warnings.append(self._addr)
+        duplicates = destinations.intersection(set(self._dests))
+        if duplicates:
+            destinations.difference_update(set(self._dests))
+            if not warnings is None:
+                warnings.extend(duplicates)
+        if not destinations:
+            return destinations
+        self.__check_expansion(len(destinations))
+        dbc = self._dbh.cursor()
+        dbc.executemany("INSERT INTO alias VALUES (%d, '%s', %%s)" %
+                        (self._gid, self._addr.localpart),
+                        (str(destination) for destination in destinations))
+        self._dbh.commit()
+        dbc.close()
+        self._dests.extend(destinations)
+        return destinations
+
+    def del_destination(self, destination):
+        """Deletes the specified ``destination`` address from the alias."""
+        assert isinstance(destination, EmailAddress)
+        if not self._dests:
+            raise AErr(_(u"The alias '%s' doesn't exist.") % self._addr,
+                       NO_SUCH_ALIAS)
+        if not destination in self._dests:
+            raise AErr(_(u"The address '%(addr)s' isn't a destination of "
+                         u"the alias '%(alias)s'.") % {'addr': self._addr,
+                       'alias': destination}, NO_SUCH_ALIAS)
+        self.__delete(destination)
+        self._dests.remove(destination)
+
+    def get_destinations(self):
+        """Returns an iterator for all destinations of the alias."""
+        if not self._dests:
+            raise AErr(_(u"The alias '%s' doesn't exist.") % self._addr,
+                       NO_SUCH_ALIAS)
+        return iter(self._dests)
+
+    def delete(self):
+        """Deletes the alias with all its destinations."""
+        if not self._dests:
+            raise AErr(_(u"The alias '%s' doesn't exist.") % self._addr,
+                       NO_SUCH_ALIAS)
+        self.__delete()
+        del self._dests[:]
+
+del _, cfg_dget