add a new method iter_process_result which does the same as proces_result but is a generator (closes #1625374)
process_result is reimplemented using the new method, and the two helper
methods are turned into generators.
These generators use cursor.fetchmany instead of cursor.fetchall after setting
cursor.arraysize to 100. This means that the whole result set should never
loaded in memory when using the iter_process_result method. This is used in the
"portable" database dump implementation when we typically to 'SELECT * FROM
table', but could probably be used too in other parts of cubicweb.
# copyright 2003-2010 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb 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 Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.
"""undoable transaction objects.
This module is in the cubicweb package and not in cubicweb.server because those
objects should be accessible to client through pyro, where the cubicweb.server
package may not be installed.
"""
__docformat__ = "restructuredtext en"
_ = unicode
from cubicweb import RepositoryError
ACTION_LABELS = {
'C': _('entity creation'),
'U': _('entity update'),
'D': _('entity deletion'),
'A': _('relation add'),
'R': _('relation removal'),
}
class NoSuchTransaction(RepositoryError):
pass
class Transaction(object):
"""an undoable transaction"""
def __init__(self, uuid, time, ueid):
self.uuid = uuid
self.datetime = time
self.user_eid = ueid
# should be set by the dbapi connection
self.req = None
def __repr__(self):
return '<Transaction %s by %s on %s>' % (
self.uuid, self.user_eid, self.datetime)
def user(self):
"""return the user entity which has done the transaction,
none if not found.
"""
return self.req.execute('Any X WHERE X eid %(x)s',
{'x': self.user_eid}).get_entity(0, 0)
def actions_list(self, public=True):
"""return an ordered list of action effectued during that transaction
if public is true, return only 'public' action, eg not ones triggered
under the cover by hooks.
"""
return self.req.cnx.transaction_actions(self.uuid, public)
class AbstractAction(object):
def __init__(self, action, public, order):
self.action = action
self.public = public
self.order = order
@property
def label(self):
return ACTION_LABELS[self.action]
class EntityAction(AbstractAction):
def __init__(self, action, public, order, etype, eid, changes):
AbstractAction.__init__(self, action, public, order)
self.etype = etype
self.eid = eid
self.changes = changes
def __repr__(self):
return '<%s: %s %s (%s)>' % (
self.label, self.eid, self.changes,
self.public and 'dbapi' or 'hook')
class RelationAction(AbstractAction):
def __init__(self, action, public, order, rtype, eidfrom, eidto):
AbstractAction.__init__(self, action, public, order)
self.rtype = rtype
self.eid_from = eidfrom
self.eid_to = eidto
def __repr__(self):
return '<%s: %s %s %s (%s)>' % (
self.label, self.eid_from, self.rtype, self.eid_to,
self.public and 'dbapi' or 'hook')