VirtualMailManager/serviceset.py
author martin f. krafft <madduck@madduck.net>
Mon, 09 Apr 2012 18:10:56 +0200
branchv0.6.x
changeset 504 f180ead60568
parent 482 428ee9cdf1b2
child 568 14abdd04ddf5
permissions -rw-r--r--
First version of a CatchallAlias class I based the CatchallAlias class in catchall.py heavily on the Alias class, but by copy, not deriving. The two are functionally related, but the implementations are too different because CatchallAliases have no localpart.

# coding: utf-8
# Copyright (c) 2011, Pascal Volk
# See COPYING for distribution information.
"""
    VirtualMailManager.serviceset
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    Virtual Mail Manager's ServiceSet class for simplified database access
    to the service_set table.
"""

SERVICES = ('smtp', 'pop3', 'imap', 'sieve')

cfg_dget = lambda option: None


class ServiceSet(object):
    """A wrapper class that provides access to the service_set table.

    Each ServiceSet object provides following - read only - attributes:

    `ssid` : long
      The id of the service set
    `smtp` : bool
      Boolean flag for service smtp
    `pop3` : bool
      Boolean flag for service pop3
    `imap` : bool
      Boolean flag for service imap
    `sieve` : bool
      Boolean flag for service sieve
    `services` : dict
      The four services above with boolean values
    """
    __slots__ = ('_ssid', '_services', '_sieve_col', '_dbh')
    _kwargs = (('ssid',) + SERVICES)

    def __init__(self, dbh, **kwargs):
        """Creates a new ServiceSet instance.

        Either the 'ssid' keyword argument or one or more of the service
        arguments ('smtp', 'pop3',  'imap', 'sieve') must be provided.

        Arguments:
        `dbh` : pyPgSQL.PgSQL.Connection or psycopg2.extensions.connection
          A database connection for the database access.

        Keyword arguments:
        `ssid` : int
          The id of the service set (>0)
        `smtp` : bool
          Boolean flag for service smtp - default `True`
        `pop3` : bool
          Boolean flag for service pop3 - default `True`
        `imap` : bool
          Boolean flag for service imap - default `True`
        `sieve` : bool
          Boolean flag for service sieve - default `True`
        """
        self._dbh = dbh
        self._ssid = 0
        self._services = dict.fromkeys(SERVICES, True)
        if cfg_dget('misc.dovecot_version') < 0x10200b02:
            self._sieve_col = 'managesieve'
        else:
            self._sieve_col = 'sieve'

        for key in kwargs.iterkeys():
            if key not in self.__class__._kwargs:
                raise ValueError('unrecognized keyword: %r' % key)
            if key == 'ssid':
                assert not isinstance(kwargs[key], bool) and \
                       isinstance(kwargs[key], (int, long)) and kwargs[key] > 0
                self._load_by_ssid(kwargs[key])
                break
            else:
                assert isinstance(kwargs[key], bool)
                if not kwargs[key]:
                    self._services[key] = kwargs[key]
        if not self._ssid:
            self._load_by_services()

    def __eq__(self, other):
        if isinstance(other, self.__class__):
            return self._ssid == other._ssid
        return NotImplemented

    def __ne__(self, other):
        if isinstance(other, self.__class__):
            return self._ssid != other._ssid
        return NotImplemented

    def __getattr__(self, name):
        if name not in self.__class__._kwargs:
            raise AttributeError('%r object has no attribute %r' % (
                                 self.__class__.__name__, name))
        if name == 'ssid':
            return self._ssid
        else:
            return self._services[name]

    def __repr__(self):
        return '%s(%s, %s)' % (self.__class__.__name__, self._dbh,
                  ', '.join('%s=%r' % s for s in self._services.iteritems()))

    def _load_by_services(self):
        """Try to load the service_set by it's service combination."""
        sql = ('SELECT ssid FROM service_set WHERE %s' %
               ' AND '.join('%s = %s' %
               (k, str(v).upper()) for k, v in self._services.iteritems()))
        if self._sieve_col == 'managesieve':
            sql.replace('sieve', self._sieve_col)
        dbc = self._dbh.cursor()
        dbc.execute(sql)
        result = dbc.fetchone()
        dbc.close()
        if result:
            self._ssid = result[0]
        else:
            self._save()

    def _load_by_ssid(self, ssid):
        """Try to load the service_set by it's primary key."""
        dbc = self._dbh.cursor()
        dbc.execute('SELECT ssid, smtp, pop3, imap, %s' % (self._sieve_col,) +
                    ' FROM service_set WHERE ssid = %s', (ssid,))
        result = dbc.fetchone()
        dbc.close()
        if not result:
            raise ValueError('Unknown service_set id specified: %r' % ssid)
        self._ssid = result[0]
        #self._services.update(zip(SERVICES, result[1:]))
        for key, value in zip(SERVICES, result[1:]):  # pyPgSQL compatible
            if value:
                self._services[key] = True
            else:
                self._services[key] = False

    def _save(self):
        """Store a new service_set in the database."""
        sql = ('INSERT INTO service_set (ssid, smtp, pop3, imap, %s) ' %
               (self._sieve_col,) +
               'VALUES (%(ssid)s, %(smtp)s, %(pop3)s, %(imap)s, %(sieve)s)')
        if self._sieve_col == 'managesieve':
            sql.replace('sieve', self._sieve_col)
        self._set_ssid()
        values = {'ssid': self._ssid}
        values.update(self._services)
        dbc = self._dbh.cursor()
        dbc.execute(sql, values)
        self._dbh.commit()
        dbc.close()

    def _set_ssid(self):
        """Set the unique ID for the new service_set."""
        assert self._ssid == 0
        dbc = self._dbh.cursor()
        dbc.execute("SELECT nextval('service_set_id')")
        self._ssid = dbc.fetchone()[0]
        dbc.close()

    @property
    def services(self):
        """A dictionary: Keys: `smtp`, `pop3`, `imap` and `sieve` with
        boolean values."""
        return self._services.copy()

del cfg_dget