--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/hooks/integrity.py Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,347 @@
+# copyright 2003-2014 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 cubicweb import _
+
+from threading import Lock
+
+from six import text_type
+
+from cubicweb import validation_error, neg_role
+from cubicweb.schema import (META_RTYPES, WORKFLOW_RTYPES,
+ RQLConstraint, RQLUniqueConstraint)
+from cubicweb.predicates import is_instance, composite_etype
+from cubicweb.uilib import soup2xhtml
+from cubicweb.server import hook
+
+# 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 = META_RTYPES | WORKFLOW_RTYPES
+DONT_CHECK_RTYPES_ON_DEL = META_RTYPES | WORKFLOW_RTYPES
+
+_UNIQUE_CONSTRAINTS_LOCK = Lock()
+_UNIQUE_CONSTRAINTS_HOLDER = None
+
+
+def _acquire_unique_cstr_lock(cnx):
+ """acquire the _UNIQUE_CONSTRAINTS_LOCK for the cnx.
+
+ This lock used to avoid potential integrity pb when checking
+ RQLUniqueConstraint in two different transactions, as explained in
+ https://extranet.logilab.fr/3577926
+ """
+ if 'uniquecstrholder' in cnx.transaction_data:
+ return
+ _UNIQUE_CONSTRAINTS_LOCK.acquire()
+ cnx.transaction_data['uniquecstrholder'] = True
+ # register operation responsible to release the lock on commit/rollback
+ _ReleaseUniqueConstraintsOperation(cnx)
+
+def _release_unique_cstr_lock(cnx):
+ if 'uniquecstrholder' in cnx.transaction_data:
+ del cnx.transaction_data['uniquecstrholder']
+ _UNIQUE_CONSTRAINTS_LOCK.release()
+
+class _ReleaseUniqueConstraintsOperation(hook.Operation):
+ def postcommit_event(self):
+ _release_unique_cstr_lock(self.cnx)
+ def rollback_event(self):
+ _release_unique_cstr_lock(self.cnx)
+
+
+class _CheckRequiredRelationOperation(hook.DataOperationMixIn,
+ hook.LateOperation):
+ """checking relation cardinality has to be done after commit in case the
+ relation is being replaced
+ """
+ containercls = list
+ role = key = base_rql = None
+
+ def precommit_event(self):
+ cnx = self.cnx
+ pendingeids = cnx.transaction_data.get('pendingeids', ())
+ pendingrtypes = cnx.transaction_data.get('pendingrtypes', ())
+ for eid, rtype in self.get_data():
+ # recheck pending eids / relation types
+ if eid in pendingeids:
+ continue
+ if rtype in pendingrtypes:
+ continue
+ if not cnx.execute(self.base_rql % rtype, {'x': eid}):
+ etype = cnx.entity_metas(eid)['type']
+ msg = _('at least one relation %(rtype)s is required on '
+ '%(etype)s (%(eid)s)')
+ raise validation_error(eid, {(rtype, self.role): msg},
+ {'rtype': rtype, 'etype': etype, 'eid': eid},
+ ['rtype', 'etype'])
+
+
+class _CheckSRelationOp(_CheckRequiredRelationOperation):
+ """check required subject relation"""
+ role = 'subject'
+ base_rql = 'Any O WHERE S eid %%(x)s, S %s O'
+
+class _CheckORelationOp(_CheckRequiredRelationOperation):
+ """check required object relation"""
+ role = 'object'
+ base_rql = 'Any S WHERE O eid %%(x)s, S %s O'
+
+
+class IntegrityHook(hook.Hook):
+ __abstract__ = True
+ category = 'integrity'
+
+
+class _EnsureSymmetricRelationsAdd(hook.Hook):
+ """ ensure X r Y => Y r X iff r is symmetric """
+ __regid__ = 'cw.add_ensure_symmetry'
+ __abstract__ = True
+ category = 'activeintegrity'
+ events = ('after_add_relation',)
+ # __select__ is set in the registration callback
+
+ def __call__(self):
+ self._cw.repo.system_source.add_relation(self._cw, self.eidto,
+ self.rtype, self.eidfrom)
+
+
+class _EnsureSymmetricRelationsDelete(hook.Hook):
+ """ ensure X r Y => Y r X iff r is symmetric """
+ __regid__ = 'cw.delete_ensure_symmetry'
+ __abstract__ = True
+ category = 'activeintegrity'
+ events = ('after_delete_relation',)
+ # __select__ is set in the registration callback
+
+ def __call__(self):
+ self._cw.repo.system_source.delete_relation(self._cw, self.eidto,
+ self.rtype, self.eidfrom)
+
+
+class CheckCardinalityHookBeforeDeleteRelation(IntegrityHook):
+ """check cardinalities are satisfied"""
+ __regid__ = 'checkcard_before_delete_relation'
+ events = ('before_delete_relation',)
+
+ def __call__(self):
+ rtype = self.rtype
+ if rtype in DONT_CHECK_RTYPES_ON_DEL:
+ return
+ cnx = self._cw
+ eidfrom, eidto = self.eidfrom, self.eidto
+ rdef = cnx.rtype_eids_rdef(rtype, eidfrom, eidto)
+ if (rdef.subject, rtype, rdef.object) in cnx.transaction_data.get('pendingrdefs', ()):
+ return
+ card = rdef.cardinality
+ if card[0] in '1+' and not cnx.deleted_in_transaction(eidfrom):
+ _CheckSRelationOp.get_instance(cnx).add_data((eidfrom, rtype))
+ if card[1] in '1+' and not cnx.deleted_in_transaction(eidto):
+ _CheckORelationOp.get_instance(cnx).add_data((eidto, rtype))
+
+
+class CheckCardinalityHookAfterAddEntity(IntegrityHook):
+ """check cardinalities are satisfied"""
+ __regid__ = 'checkcard_after_add_entity'
+ events = ('after_add_entity',)
+
+ def __call__(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':
+ op = _CheckSRelationOp.get_instance(self._cw)
+ else:
+ op = _CheckORelationOp.get_instance(self._cw)
+ op.add_data((eid, rschema.type))
+
+
+class _CheckConstraintsOp(hook.DataOperationMixIn, hook.LateOperation):
+ """ check a new relation satisfy its constraints """
+ containercls = list
+ def precommit_event(self):
+ cnx = self.cnx
+ for values in self.get_data():
+ eidfrom, rtype, eidto, constraints = values
+ # first check related entities have not been deleted in the same
+ # transaction
+ if cnx.deleted_in_transaction(eidfrom):
+ continue
+ if cnx.deleted_in_transaction(eidto):
+ continue
+ 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(cnx)
+ try:
+ constraint.repo_check(cnx, eidfrom, rtype, eidto)
+ except NotImplementedError:
+ self.critical('can\'t check constraint %s, not supported',
+ constraint)
+
+
+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?
+ rdef = self._cw.rtype_eids_rdef(self.rtype, self.eidfrom, self.eidto)
+ constraints = rdef.constraints
+ if constraints:
+ _CheckConstraintsOp.get_instance(self._cw).add_data(
+ (self.eidfrom, self.rtype, self.eidto, constraints))
+
+
+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.cw_edited:
+ if eschema.subjrels[attr].final:
+ constraints = [c for c in eschema.rdef(attr).constraints
+ if isinstance(c, (RQLUniqueConstraint, RQLConstraint))]
+ if constraints:
+ _CheckConstraintsOp.get_instance(self._cw).add_data(
+ (self.entity.eid, attr, None, constraints))
+
+
+class CheckUniqueHook(IntegrityHook):
+ __regid__ = 'checkunique'
+ events = ('before_add_entity', 'before_update_entity')
+
+ def __call__(self):
+ entity = self.entity
+ eschema = entity.e_schema
+ for attr, val in entity.cw_edited.items():
+ if eschema.subjrels[attr].final and eschema.has_unique_values(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 = _('the value "%s" is already used, use another one')
+ raise validation_error(entity, {(attr, 'subject'): msg},
+ (val,))
+
+
+class DontRemoveOwnersGroupHook(IntegrityHook):
+ """delete the composed of a composite relation when this relation is deleted
+ """
+ __regid__ = 'checkownersgroup'
+ __select__ = IntegrityHook.__select__ & is_instance('CWGroup')
+ events = ('before_delete_entity', 'before_update_entity')
+
+ def __call__(self):
+ entity = self.entity
+ if self.event == 'before_delete_entity' and entity.name == 'owners':
+ raise validation_error(entity, {None: _("can't be deleted")})
+ elif self.event == 'before_update_entity' \
+ and 'name' in entity.cw_edited:
+ oldname, newname = entity.cw_edited.oldnewvalue('name')
+ if oldname == 'owners' and newname != oldname:
+ raise validation_error(entity, {('name', 'subject'): _("can't be changed")})
+
+
+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()
+ edited = entity.cw_edited
+ for metaattr, (metadata, attr) in metaattrs.items():
+ if metadata == 'format' and attr in edited:
+ try:
+ value = edited[attr]
+ except KeyError:
+ continue # no text to tidy
+ if isinstance(value, text_type): # filter out None and Binary
+ if getattr(entity, str(metaattr)) == 'text/html':
+ edited[attr] = soup2xhtml(value, self._cw.encoding)
+
+
+class StripCWUserLoginHook(IntegrityHook):
+ """ensure user logins are stripped"""
+ __regid__ = 'stripuserlogin'
+ __select__ = IntegrityHook.__select__ & is_instance('CWUser')
+ events = ('before_add_entity', 'before_update_entity',)
+
+ def __call__(self):
+ login = self.entity.cw_edited.get('login')
+ if login:
+ self.entity.cw_edited['login'] = login.strip()
+
+
+class DeleteCompositeOrphanHook(hook.Hook):
+ """Delete the composed of a composite relation when the composite is
+ deleted (this is similar to the cascading ON DELETE CASCADE
+ semantics of sql).
+ """
+ __regid__ = 'deletecomposite'
+ __select__ = hook.Hook.__select__ & composite_etype()
+ events = ('before_delete_entity',)
+ category = 'activeintegrity'
+ # give the application's before_delete_entity hooks a chance to run before we cascade
+ order = 99
+
+ def __call__(self):
+ eid = self.entity.eid
+ for rdef, role in self.entity.e_schema.composite_rdef_roles:
+ rtype = rdef.rtype.type
+ target = getattr(rdef, neg_role(role))
+ expr = ('C %s X' % rtype) if role == 'subject' else ('X %s C' % rtype)
+ self._cw.execute('DELETE %s X WHERE C eid %%(c)s, %s' % (target, expr),
+ {'c': eid})
+
+
+def registration_callback(vreg):
+ vreg.register_all(globals().values(), __name__)
+ symmetric_rtypes = [rschema.type for rschema in vreg.schema.relations()
+ if rschema.symmetric]
+ class EnsureSymmetricRelationsAdd(_EnsureSymmetricRelationsAdd):
+ __select__ = _EnsureSymmetricRelationsAdd.__select__ & hook.match_rtype(*symmetric_rtypes)
+ vreg.register(EnsureSymmetricRelationsAdd)
+ class EnsureSymmetricRelationsDelete(_EnsureSymmetricRelationsDelete):
+ __select__ = _EnsureSymmetricRelationsDelete.__select__ & hook.match_rtype(*symmetric_rtypes)
+ vreg.register(EnsureSymmetricRelationsDelete)