# 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/>.
"""Core hooks: check for data integrity according to the instance'schema
validity
"""
__docformat__ = "restructuredtext en"
from threading import Lock
from yams.schema import role_name
from cubicweb import ValidationError
from cubicweb.schema import RQLConstraint, RQLUniqueConstraint
from cubicweb.selectors import implements
from cubicweb.uilib import soup2xhtml
from cubicweb.server import hook
from cubicweb.server.hook import set_operation
# special relations that don't have to be checked for integrity, usually
# because they are handled internally by hooks (so we trust ourselves)
DONT_CHECK_RTYPES_ON_ADD = set(('owned_by', 'created_by',
'is', 'is_instance_of',
'wf_info_for', 'from_state', 'to_state'))
DONT_CHECK_RTYPES_ON_DEL = set(('is', 'is_instance_of',
'wf_info_for', 'from_state', 'to_state'))
_UNIQUE_CONSTRAINTS_LOCK = Lock()
_UNIQUE_CONSTRAINTS_HOLDER = None
def _acquire_unique_cstr_lock(session):
"""acquire the _UNIQUE_CONSTRAINTS_LOCK for the session.
This lock used to avoid potential integrity pb when checking
RQLUniqueConstraint in two different transactions, as explained in
http://intranet.logilab.fr/jpl/ticket/36564
"""
if 'uniquecstrholder' in session.transaction_data:
return
_UNIQUE_CONSTRAINTS_LOCK.acquire()
session.transaction_data['uniquecstrholder'] = True
# register operation responsible to release the lock on commit/rollback
_ReleaseUniqueConstraintsOperation(session)
def _release_unique_cstr_lock(session):
if 'uniquecstrholder' in session.transaction_data:
del session.transaction_data['uniquecstrholder']
_UNIQUE_CONSTRAINTS_LOCK.release()
class _ReleaseUniqueConstraintsOperation(hook.Operation):
def commit_event(self):
pass
def postcommit_event(self):
_release_unique_cstr_lock(self.session)
def rollback_event(self):
_release_unique_cstr_lock(self.session)
class _CheckRequiredRelationOperation(hook.LateOperation):
"""checking relation cardinality has to be done after commit in
case the relation is being replaced
"""
role = key = base_rql = None
def precommit_event(self):
session =self.session
pendingeids = session.transaction_data.get('pendingeids', ())
pendingrtypes = session.transaction_data.get('pendingrtypes', ())
# poping key is not optional: if further operation trigger new deletion
# of relation, we'll need a new operation
for eid, rtype in session.transaction_data.pop(self.key):
# recheck pending eids / relation types
if eid in pendingeids:
continue
if rtype in pendingrtypes:
continue
if not session.execute(self.base_rql % rtype, {'x': eid}):
etype = session.describe(eid)[0]
_ = session._
msg = _('at least one relation %(rtype)s is required on '
'%(etype)s (%(eid)s)')
msg %= {'rtype': _(rtype), 'etype': _(etype), 'eid': eid}
raise ValidationError(eid, {role_name(rtype, self.role): msg})
class _CheckSRelationOp(_CheckRequiredRelationOperation):
"""check required subject relation"""
role = 'subject'
key = '_cwisrel'
base_rql = 'Any O WHERE S eid %%(x)s, S %s O'
class _CheckORelationOp(_CheckRequiredRelationOperation):
"""check required object relation"""
role = 'object'
key = '_cwiorel'
base_rql = 'Any S WHERE O eid %%(x)s, S %s O'
class IntegrityHook(hook.Hook):
__abstract__ = True
category = 'integrity'
class CheckCardinalityHook(IntegrityHook):
"""check cardinalities are satisfied"""
__regid__ = 'checkcard'
events = ('after_add_entity', 'before_delete_relation')
def __call__(self):
getattr(self, self.event)()
def after_add_entity(self):
eid = self.entity.eid
eschema = self.entity.e_schema
for rschema, targetschemas, role in eschema.relation_definitions():
# skip automatically handled relations
if rschema.type in DONT_CHECK_RTYPES_ON_ADD:
continue
rdef = rschema.role_rdef(eschema, targetschemas[0], role)
if rdef.role_cardinality(role) in '1+':
if role == 'subject':
set_operation(self._cw, '_cwisrel', (eid, rschema.type),
_CheckSRelationOp, list)
else:
set_operation(self._cw, '_cwiorel', (eid, rschema.type),
_CheckORelationOp, list)
def before_delete_relation(self):
rtype = self.rtype
if rtype in DONT_CHECK_RTYPES_ON_DEL:
return
session = self._cw
eidfrom, eidto = self.eidfrom, self.eidto
pendingrdefs = session.transaction_data.get('pendingrdefs', ())
if (session.describe(eidfrom)[0], rtype, session.describe(eidto)[0]) in pendingrdefs:
return
card = session.schema_rproperty(rtype, eidfrom, eidto, 'cardinality')
if card[0] in '1+' and not session.deleted_in_transaction(eidfrom):
set_operation(self._cw, '_cwisrel', (eidfrom, rtype),
_CheckSRelationOp, list)
if card[1] in '1+' and not session.deleted_in_transaction(eidto):
set_operation(self._cw, '_cwiorel', (eidto, rtype),
_CheckORelationOp, list)
class _CheckConstraintsOp(hook.LateOperation):
""" check a new relation satisfy its constraints """
def precommit_event(self):
session = self.session
for values in session.transaction_data.pop('check_constraints_op'):
eidfrom, rtype, eidto, constraints = values
# first check related entities have not been deleted in the same
# transaction
if session.deleted_in_transaction(eidfrom):
return
if session.deleted_in_transaction(eidto):
return
for constraint in constraints:
# XXX
# * lock RQLConstraint as well?
# * use a constraint id to use per constraint lock and avoid
# unnecessary commit serialization ?
if isinstance(constraint, RQLUniqueConstraint):
_acquire_unique_cstr_lock(session)
try:
constraint.repo_check(session, eidfrom, rtype, eidto)
except NotImplementedError:
self.critical('can\'t check constraint %s, not supported',
constraint)
def commit_event(self):
pass
class CheckConstraintHook(IntegrityHook):
"""check the relation satisfy its constraints
this is delayed to a precommit time operation since other relation which
will make constraint satisfied (or unsatisfied) may be added later.
"""
__regid__ = 'checkconstraint'
events = ('after_add_relation',)
def __call__(self):
# XXX get only RQL[Unique]Constraints?
constraints = self._cw.schema_rproperty(self.rtype, self.eidfrom, self.eidto,
'constraints')
if constraints:
hook.set_operation(self._cw, 'check_constraints_op',
(self.eidfrom, self.rtype, self.eidto, tuple(constraints)),
_CheckConstraintsOp, list)
class CheckAttributeConstraintHook(IntegrityHook):
"""check the attribute relation satisfy its constraints
this is delayed to a precommit time operation since other relation which
will make constraint satisfied (or unsatisfied) may be added later.
"""
__regid__ = 'checkattrconstraint'
events = ('after_add_entity', 'after_update_entity')
def __call__(self):
eschema = self.entity.e_schema
for attr in self.entity.edited_attributes:
if eschema.subjrels[attr].final:
constraints = [c for c in eschema.rdef(attr).constraints
if isinstance(c, (RQLUniqueConstraint, RQLConstraint))]
if constraints:
hook.set_operation(self._cw, 'check_constraints_op',
(self.entity.eid, attr, None, tuple(constraints)),
_CheckConstraintsOp, list)
class CheckUniqueHook(IntegrityHook):
__regid__ = 'checkunique'
events = ('before_add_entity', 'before_update_entity')
def __call__(self):
entity = self.entity
eschema = entity.e_schema
for attr in entity.edited_attributes:
if eschema.subjrels[attr].final and eschema.has_unique_values(attr):
val = entity[attr]
if val is None:
continue
rql = '%s X WHERE X %s %%(val)s' % (entity.e_schema, attr)
rset = self._cw.execute(rql, {'val': val})
if rset and rset[0][0] != entity.eid:
msg = self._cw._('the value "%s" is already used, use another one')
qname = role_name(attr, 'subject')
raise ValidationError(entity.eid, {qname: msg % val})
class DontRemoveOwnersGroupHook(IntegrityHook):
"""delete the composed of a composite relation when this relation is deleted
"""
__regid__ = 'checkownersgroup'
__select__ = IntegrityHook.__select__ & implements('CWGroup')
events = ('before_delete_entity', 'before_update_entity')
def __call__(self):
if self.event == 'before_delete_entity' and self.entity.name == 'owners':
msg = self._cw._('can\'t be deleted')
raise ValidationError(self.entity.eid, {None: msg})
elif self.event == 'before_update_entity' and \
'name' in self.entity.edited_attributes:
newname = self.entity.pop('name')
oldname = self.entity.name
if oldname == 'owners' and newname != oldname:
qname = role_name('name', 'subject')
msg = self._cw._('can\'t be changed')
raise ValidationError(self.entity.eid, {qname: msg})
self.entity['name'] = newname
class TidyHtmlFields(IntegrityHook):
"""tidy HTML in rich text strings"""
__regid__ = 'htmltidy'
events = ('before_add_entity', 'before_update_entity')
def __call__(self):
entity = self.entity
metaattrs = entity.e_schema.meta_attributes()
for metaattr, (metadata, attr) in metaattrs.iteritems():
if metadata == 'format' and attr in entity.edited_attributes:
try:
value = entity[attr]
except KeyError:
continue # no text to tidy
if isinstance(value, unicode): # filter out None and Binary
if getattr(entity, str(metaattr)) == 'text/html':
entity[attr] = soup2xhtml(value, self._cw.encoding)
class StripCWUserLoginHook(IntegrityHook):
"""ensure user logins are stripped"""
__regid__ = 'stripuserlogin'
__select__ = IntegrityHook.__select__ & implements('CWUser')
events = ('before_add_entity', 'before_update_entity',)
def __call__(self):
user = self.entity
if 'login' in user.edited_attributes and user.login:
user.login = user.login.strip()
# 'active' integrity hooks: you usually don't want to deactivate them, they are
# not really integrity check, they maintain consistency on changes
class _DelayedDeleteOp(hook.Operation):
"""delete the object of composite relation except if the relation has
actually been redirected to another composite
"""
key = base_rql = None
def precommit_event(self):
session = self.session
pendingeids = session.transaction_data.get('pendingeids', ())
neweids = session.transaction_data.get('neweids', ())
# poping key is not optional: if further operation trigger new deletion
# of composite relation, we'll need a new operation
for eid, rtype in session.transaction_data.pop(self.key):
# don't do anything if the entity is being created or deleted
if not (eid in pendingeids or eid in neweids):
etype = session.describe(eid)[0]
session.execute(self.base_rql % (etype, rtype), {'x': eid})
class _DelayedDeleteSEntityOp(_DelayedDeleteOp):
"""delete orphan subject entity of a composite relation"""
key = '_cwiscomp'
base_rql = 'DELETE %s X WHERE X eid %%(x)s, NOT X %s Y'
class _DelayedDeleteOEntityOp(_DelayedDeleteOp):
"""check required object relation"""
key = '_cwiocomp'
base_rql = 'DELETE %s X WHERE X eid %%(x)s, NOT Y %s X'
class DeleteCompositeOrphanHook(hook.Hook):
"""delete the composed of a composite relation when this relation is deleted
"""
__regid__ = 'deletecomposite'
events = ('before_delete_relation',)
category = 'activeintegrity'
def __call__(self):
# if the relation is being delete, don't delete composite's components
# automatically
pendingrdefs = self._cw.transaction_data.get('pendingrdefs', ())
if (self._cw.describe(self.eidfrom)[0], self.rtype,
self._cw.describe(self.eidto)[0]) in pendingrdefs:
return
composite = self._cw.schema_rproperty(self.rtype, self.eidfrom, self.eidto,
'composite')
if composite == 'subject':
set_operation(self._cw, '_cwiocomp', (self.eidto, self.rtype),
_DelayedDeleteOEntityOp)
elif composite == 'object':
set_operation(self._cw, '_cwiscomp', (self.eidfrom, self.rtype),
_DelayedDeleteSEntityOp)