Synnefo » Pithos

            if until:

                raise NotAllowedError

            containers = self._allowed_containers(user, account)

            start = 0

            if marker:

                try:

                    start = containers.index(marker) + 1

                except ValueError:

                    pass

            if not limit or limit > 10000:

                limit = 10000

            return containers[start:start + limit]

    def _is_allowed(self, user, account, container, name, op='read'):

        if user == account:

            return True

        path = os.path.join(account, container, name)

        if op == 'read' and self._get_public(path):

            return True

        perm_path, perms = self._get_permissions(path)

        # Expand groups.

        for x in ('read', 'write'):

            g_perms = set()

            for y in perms.get(x, []):

                if ':' in y:

                    g_account, g_name = y.split(':', 1)

                    groups = self._get_groups(g_account)

                    if g_name in groups:

                        g_perms.update(groups[g_name])

                else:

                    g_perms.add(y)

            perms[x] = g_perms

        if op == 'read' and ('*' in perms['read'] or user in perms['read']):

            return True

        if '*' in perms['write'] or user in perms['write']:

            return True

        return False

    def _can_read(self, user, account, container, name):

        if not self._is_allowed(user, account, container, name, 'read'):

            raise NotAllowedError

    def _can_write(self, user, account, container, name):

        if not self._is_allowed(user, account, container, name, 'write'):

            raise NotAllowedError

    def _allowed_paths(self, user, prefix=None):

        sql = '''select distinct name from permissions where (user = ?

                    or user in (select account || ':' || gname from groups where user = ?))'''

        param = (user, user)

        if prefix:

            sql += ' and name like ?'

            param += (prefix + '/%',)

        c = self.con.execute(sql, param)

        return [x[0] for x in c.fetchall()]

    def _allowed_accounts(self, user):

        allow = set()

        for path in self._allowed_paths(user):

            allow.add(path.split('/', 1)[0])

        return sorted(allow)

    def _allowed_containers(self, user, account):

        allow = set()

        for path in self._allowed_paths(user, account):

            allow.add(path.split('/', 2)[1])

        return sorted(allow)